Showing papers in "International Journal of Obesity in 2000"
TL;DR: VAS scores are reliable for appetite research and do not seem to be influenced by prior diet standardization, however, consideration should be given to the specific parameters being measured, their sensitivity and study power.
Abstract: OBJECTIVE: To examine reproducibility and validity of visual analogue scales (VAS) for measurement of appetite sensations, with and without a diet standardization prior to the test days DESIGN: On two different test days the subjects recorded their appetite sensations before breakfast and every 30 min during the 45 h postprandial period under exactly the same conditions SUBJECTS: 55 healthy men (age 256±06 y, BMI 226±03 kg/m2) MEASUREMENTS: VAS were used to record hunger, satiety, fullness, prospective food consumption, desire to eat something fatty, salty, sweet or savoury, and palatability of the meals Subsequently an ad libitum lunch was served and energy intake was recorded Reproducibility was assessed by the coefficient of repeatability (CR) of fasting, mean 45 h and peak/nadir values RESULTS: CRs (range 20–61 mm) were larger for fasting and peak/nadir values compared with mean 45 h values No parameter seemed to be improved by diet standardization Using a paired design and a study power of 08, a difference of 10 mm on fasting and 5 mm on mean 45 h ratings can be detected with 18 subjects When using desires to eat specific types of food or an unpaired design, more subjects are needed due to considerable variation The best correlations of validity were found between 45 h mean VAS of the appetite parameters and subsequent energy intake (r=±050−053, P<0001) CONCLUSION: VAS scores are reliable for appetite research and do not seem to be influenced by prior diet standardization However, consideration should be given to the specific parameters being measured, their sensitivity and study power
1,927 citations
TL;DR: The Goldberg cut-off can be used to evaluate the mean population bias in reported energy intake, but information on the activity or lifestyle of the population is needed to choose a suitable PAL energy requirement for comparison.
Abstract: OBJECTIVES: To re-state the principles underlying the Goldberg cut-off for identifying under-reporters of energy intake, re-examine the physiological principles and update the values to be substituted into the equation for calculating the cut-off, and to examine its use and limitations. RESULTS: New values are suggested for each element of the Goldberg equation. The physical activity level (PAL) for comparison with energy intake:basal metabolic rate (EI:BMR) should be selected to reflect the population under study; the PAL value of 1.55 x BMR is not necessarily the value of choice. The suggested value for average within-subject variation in energy intake is 23% (unchanged), but other sources of variation are increased in the light of new data. For within-subject variation in measured and estimated BMR, 4% and 8.5% respectively are suggested (previously 2.5% and 8%), and for total between-subject variation in PAL, the suggested value is 15% (previously 12.5%). The effect of these changes is to widen the confidence limits and reduce the sensitivity of the cut-off. CONCLUSIONS: The Goldberg cut-off can be used to evaluate the mean population bias in reported energy intake, but information on the activity or lifestyle of the population is needed to choose a suitable PAL energy requirement for comparison. Sensitivity for identifying under-reporters at the individual level is limited. In epidemiological studies information on home, leisure and occupational activity is essential in order to assign subjects to low, medium or high PAL levels before calculating the cut-offs. In small studies, it is desirable to measure energy expenditure, or to calculate individual energy requirements, and to compare energy intake directly with energy expenditure.
1,318 citations
TL;DR: W waist circumference was the most significant predictor for all variables both for boys and girls, whereas BMI had the lowest predictive value for the detection of cardiovascular disease risk factors.
Abstract: BACKGROUND: Visceral adipose tissue is associated with increased risk for cardiovascular disease risk factors and morbidity from cardiovascular diseases. Waist measurement and waist-to-height ratio (WHtR) have been used as proxy measures of visceral adipose tissue, mainly in adults. OBJECTIVE: To validate body mass index (BMI), waist circumference and WHtR as predictors for the presence of cardiovascular disease risk factors in children of Greek-Cypriot origin. SUBJECTS AND METHODS: A total of 1037 boys and 950 girls with mean age 11.4±0.4 y were evaluated. Dependent variables for the study were total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholestrol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and systolic (SBP) and diastolic (DBP) blood pressure. RESULTS: When children were divided into two groups according to the 75th percentile for BMI, waist circumference and WHtR, all dependent variables had higher mean values in the highest percentile groups in WHtR groups and almost all variables in BMI and waist circumference groups. Adjusted odds ratios for predicting pathological values of cardiovascular disease risk factors were slightly higher for the highest WHtR group for predicting lipid and lipoprotein pathological values and for the highest BMI groups in predicting high blood pressure measurement. Using stepwise multiple regression analysis to explain the variance of the dependent variables, waist circumference was the most significant predictor for all variables both for boys and girls, whereas BMI had the lowest predictive value for the detection of cardiovascular disease risk factors. CONCLUSION: Waist circumference and WHtR are better predictors of cardiovascular disease risk factors in children than BMI. Further studies are necessary to determine the cutoff points for these indices for an accurate prediction of risk factors.
936 citations
TL;DR: It is indicated that liquid carbohydrate promotes positive energy balance, whereas a comparable solid carbohydrate elicits precise dietary compensation and increased consumption of energy-yielding fluids may promotepositive energy balance.
Abstract: BACKGROUND: Beverages are contributing an increased proportion of energy to the diet. Because they elicit a weak compensatory dietary response, they may increase risk of positive energy balance. OBJECTIVES: This study aimed to document the differential effects of matched liquid and solid carbohydrate loads on diet and body weight. DESIGN: In a cross-over design, seven males and eight females consumed dietary carbohydrate loads of 1880 kJ/day as a liquid (soda) or solid (jelly beans) during two 4 week periods separated by a 4 week washout. Subjects were permitted to consume the loads however they chose. In addition to baseline measurements, diet records were obtained on random days throughout the study, body composition was measured weekly, physical activity was assessed before and after treatments and hunger was assessed during washout and midway through each treatment. RESULTS: Free-feeding energy intake during the solid period was significantly lower than intake prior to this period. Dietary energy compensation was precise (118%). No decrease in free-feeding energy intake occurred during the liquid period. Total daily energy intake increased by an amount equal to the load resulting in dietary compensation of −17%. Consequently, body weight and BMI increased significantly only during the liquid period. Physical activity and hunger were unchanged. CONCLUSIONS: This study indicates that liquid carbohydrate promotes positive energy balance, whereas a comparable solid carbohydrate elicits precise dietary compensation. Increased consumption of energy-yielding fluids may promote positive energy balance.
878 citations
TL;DR: A short, revised 18-item instrument was constructed, representing the derived factors of Cognitive Restraint, Uncontrolled Eating and Emotional Eating, and the most efficient items were used to boost both the convergent and discriminant validity of the scales.
Abstract: OBJECTIVE: To evaluate the construct validity of the Three-Factor Eating Questionnaire (TFEQ) in obese men and women. SUBJECTS: A total of 4377 middle-aged, obese subjects in the Swedish Obese Subjects (SOS) study. METHODS: The total sample was randomly split into two data subsets and psychometric testing was performed separately in each sample. Multitrait/multi-item analysis was conducted to test scaling assumptions and factor analysis was used to test the factor structure. Measures of mental well-being (MACL, HAD) were used for testing criterion-based validity. RESULTS: The Cognitive Restraint factor was consistently reproduced and scaling analysis demonstrated strong item-scale discriminant validity, while the item-scale convergent validity was unsatisfactory. The internal structure of the Disinhibition scale was weak. Most Disinhibition and Hunger items grouped in one global factor labeled Uncontrolled Eating. A third cluster containing items on Emotional Eating was also identified. The obtained three-factor structure was cross-validated and replicated across subgroups by gender, age and BMI. CONCLUSION: The original TFEQ factor structure was not replicated. A short, revised 18-item instrument was constructed, representing the derived factors of Cognitive Restraint, Uncontrolled Eating and Emotional Eating. The most efficient items were used to boost both the convergent and discriminant validity of the scales.
849 citations
TL;DR: Stress-induced hypercortisolism and visceral obesity and their cardiovascular and other sequelae increase the all-cause mortality risk of affected subjects by 2–3-fold and curtail their life expectancy by several years.
Abstract: The stress system coordinates the adaptive response of the organism to real or perceived stressors. The main components of the stress system are the corticotropin-releasing hormone (CRH) and locus ceruleus-norepinephrine/ autonomic (LC/NE) systems and their peripheral effectors, the hypothalamic-pituitary-adrenal (HPA) axis, and the limbs of the autonomic system. Activation of the stress system leads to behavioral and peripheral changes that improve the ability of the organism to adjust homeostasis and increase its chances for survival. Thus, CRH and the LC/NE system stimulate arousal and attention, as well as the mesocorticolimbic dopaminergic system, which is involved in anticipatory and reward phenomena, and the amygdala, which are responsible for the generation of fear. Hypothalamic CRH plays an important role in inhibiting gonadotropin-releasing hormone secretion during stress, while via somatostatin it also inhibits growth hormone, thyrotropin-releasing hormone and thyrotropin secretion, suppressing thus reproduction, growth and thyroid function. Glucocorticoids directly inhibit pituitary gonadotropin, growth hormone and thyrotropin secretion and make the target tissues of sex steroids and growth factors resistant to these substances. In addition, glucocorticoids stimulate hepatic gluconeogenesis, and inhibit or potentiate insulin actions on skeletal muscle and adipose tissue respectively, ultimately promoting visceral adiposity and the metabolic syndrome. Glucocorticoids also have direct effects on the bone, inhibiting osteoblastic activity and causing osteoporosis. Obese subjects with psychiatric manifestations ranging from those of melancholic depression to anxiety with perception of 'uncontrollable' stress, frequently have mild hypercortisolism, while carefully screened obese subjects with no such manifestations are eucortisolemic. The former may have stress-induced glucocorticoid-mediated visceral obesity and metabolic syndrome manifestations, which in the extreme may be called a pseudo-Cushing state that needs to be differentiated from frank Cushing syndrome. Stress-induced hypercortisolism and visceral obesity and their cardiovascular and other sequelae increase the all-cause mortality risk of affected subjects by 2-3-fold and curtail their life expectancy by several years.
613 citations
TL;DR: The present study demonstrated that the development of high fat diet-induced obesity in C57 B1/6J mice could be divided into three stages: an early stage in response to high-fat diet that mice were sensitive to exogenous leptin; a reduced food intake stage when mice had an increase in leptin production and still retained central leptin sensitivity; and an increasedFood intake stage, accompanied by a reduction of central leptinensitivity.
Abstract: OBJECTIVE: To investigate the development of high fat diet-induced obesity and leptin resistance. DESIGN: Two experiments were carried out in this study. Firstly, we fed the mice with a high- or low-fat diet for up to 19 weeks to examine a progressive development of high fat diet-induced obesity. Secondly, we examined peripheral and central exogenous leptin sensitivity in mice fed high- or low-fat diets for 1, 8 or 19 weeks. SUBJECTS: A total of 168 C57BL/6J mice (3 weeks old) were used in this study. MEASUREMENTS: In the first experiment, we measured the body weight, energy intake, adipose tissue mass, tibia bone length, and plasma leptin in mice fed either a high- or low-fat diet for 1, 8, 15 and 19 weeks. In the second experiment, body weight change and cumulative energy intake were measured at 6 h intervals for 72 h after leptin injection in mice fed a high- or low-fat diet for 1, 8 or 19 weeks. RESULTS: The results from the first experiment suggested that the development of high fat diet-induced obesity in mice could be divided into early, middle and late stages. Compared with the mice fed a low-fat diet, the mice fed a high-fat diet showed a gradually increased body weight (+5.2%), fat storage (epididymal plus perirenal; +6.7%) and plasma leptin (+18%) at 1 week; +11.4%, +68.1%, and +223%, respectively, at 8 weeks; and +30.5%, +141%, and +458%, respectively, at 19 weeks. Energy intake of high fat diet-fed mice was equal to that of low fat diet-fed controls for the first 3 weeks; it fell below control levels over the next 5 week period, but began to increase gradually after 8 weeks of high-fat diet feeding and then increased dramatically from 15 weeks to be 14% higher than that of controls after 19 weeks. The results from our second experiment showed that: (1) after 1 week of feeding, the mice fed a high-fat diet were sensitive to a 2 μg/g (body weight) intraperitoneal (i.p.) injection of leptin, with no differences in body weight change or cumulative energy intake post-injection; (2) after 8 weeks of feeding, the mice fed a high-fat diet were insensitive to 2 μg/g (body weight) i.p. leptin, but were sensitive to a 0.1 μg intracerebroventricular (i.c.v.) injection of leptin; (3) after 19 weeks of feeding, the mice fed a high-fat diet were insensitive to 0.1 μg i.c.v. leptin, but were sensitive to a high dose of 2 μg i.c.v. leptin. CONCLUSIONS: The present study demonstrated that the development of high fat diet-induced obesity (19 weeks) in C57 B1/6J mice could be divided into three stages: (1) an early stage in response to high-fat diet that mice were sensitive to exogenous leptin; (2) a reduced food intake stage when mice had an increase in leptin production and still retained central leptin sensitivity; and (3) an increased food intake stage, accompanied by a reduction of central leptin sensitivity.
571 citations
TL;DR: The results show that the relationship between BF% and BMI is different between Singaporeans and Caucasians and also among the three ethnic groups in Singapore, and the cut-off points for obesity in Singapore based on the BMI would need to be lowered.
Abstract: Objective To study the relationship between body fat percentage and body mass index (BMI) in three different ethnic groups in Singapore (Chinese, Malays and Indians) in order to evaluate the validity of the BMI cut-off points for obesity. Design Cross-sectional study. Subjects Two-hundred and ninety-one subjects, purposively selected to ensure adequate representation of range of age and BMI of the general adult population, with almost equal numbers from each ethnic and gender group. Measurements Body weight, body height, sitting height, wrist and femoral widths, skinfold thicknesses, total body water by deuterium oxide dilution, densitometry with Bodpod(R) and bone mineral content with Hologic(R) QDR-4500. Body fat percentage was calculated using a four-compartment model. Results Compared with body fat percentage (BF%) obtained using the reference method, BF% for the Singaporean Chinese, Malays and Indians were under-predicted by BMI, sex and age when an equation developed in a Caucasian population was used. The mean prediction error ranged from 2.7% to 5.6% body fat. The BMI/BF% relationship was also different among the three Singaporean groups, with Indians having the highest BF% and Chinese the lowest for the same BMI. These differences could be ascribed to differences in body build. It was also found that for the same amount of body fat as Caucasians who have a body mass index (BMI) of 30 kg/m2 (cut-off for obesity as defined by WHO), the BMI cut-off points for obesity would have to be about 27 kg/m2 for Chinese and Malays and 26 kg/m2 for Indians. Conclusions The results show that the relationship between BF% and BMI is different between Singaporeans and Caucasians and also among the three ethnic groups in Singapore. If obesity is regarded as an excess of body fat and not as an excess of weight (increased BMI), the cut-off points for obesity in Singapore based on the BMI would need to be lowered. This would have immense public health implications in terms of policy related to obesity prevention and management.
565 citations
Journal Article•
TL;DR: Frequency of fast food restaurant use is associated with higher energy and fat intake and greater body weight, and could be an important risk factor for excess weight gain in the population.
550 citations
TL;DR: In this article, the frequency of fast food restaurant use was associated with higher total energy intake, higher percentage fat energy, more frequent consumption of hamburgers, French fries and soft drinks, and less frequent consumption consumption of fiber and fruit.
Abstract: OBJECTIVE: To examine demographic, behavioral and dietary correlates of frequency of fast food restaurant use in a community-based sample of 891 adult women. DESIGN: A survey was administered at baseline and 3 y later as part of a randomized, prospective intervention trial on weight gain prevention. SUBJECTS: Women (n=891) aged 20–45 y who enrolled in the Pound of Prevention study. MEASUREMENTS: Frequency of fast food restaurant use, dietary intake, demographic and behavioral measures were self-reported. Dietary intake was measured using the 60-item Block Food Frequency Questionnaire. Body weight and height were directly measured. RESULTS: Twenty-one percent of the sample reported eating ≥3 fast food meals per week. Frequency of fast food restaurant use was associated with higher total energy intake, higher percentage fat energy, more frequent consumption of hamburgers, French fries and soft drinks, and less frequent consumption of fiber and fruit. Frequency of fast food restaurant use was higher among younger women, those with lower income, non-White ethnicity, greater body weight, lower dietary restraint, fewer low-fat eating behaviors, and greater television viewing. Over 3 y, increases in frequency of fast food restaurant use were associated with increases in body weight, total energy intake, percentage fat intake, intake of hamburgers, French fries and soft drinks, and with decreases in physical activity, dietary restraint and low-fat eating behaviors. Intake of several other foods, including fruits and vegetables, did not differ by frequency of fast food restaurant use. CONCLUSION: Frequency of fast food restaurant use is associated with higher energy and fat intake and greater body weight, and could be an important risk factor for excess weight gain in the population.
549 citations
TL;DR: These changes in the distribution of BMI suggest the combination of both profound environmental determinants and a population with a high degree of susceptibility, suggesting an increase in BMI across the entire population.
Abstract: BACKGROUND: National survey data show increases in mean body mass index (BMI) and in the prevalence of overweight and obesity for adults and children in the United States, indicating a change in the distribution of BMI. OBJECTIVE: To apply graphical methods to describe changes in the distribution of BMI. DESIGN: BMI values from the third National Health and Nutrition Examination Survey (NHANES III: 1988–94) were compared with data from earlier cross-sectional nationally representative surveys for adults 20–74 y of age and for children and adolescents 6–17 y of age. Tukey mean–difference plots were used to investigate the changes in the distributions of BMI within sex–age groups. RESULTS: Mean–difference plots allow qualitative visual comparisons of the distributions of BMI between surveys. For all sex–age groups, there was increasing skewness with a greater shift in the upper part of the distribution so that, within each group, the heaviest subgroup was heavier in NHANES III than in prior surveys. For the youngest children, the lower part of the distribution showed virtually no change. With increasing age the whole distribution tended to shift upward slightly, suggesting an increase in BMI across the entire population. CONCLUSIONS: These changes in the distribution of BMI suggest the combination of both profound environmental determinants and a population with a high degree of susceptibility. The reasons for the increasing prevalence of obesity should be sought in part by seeking to understand the factors causing increases in the population as a whole.
TL;DR: The findings suggest that self-reported weight and height should be treated with caution, because of biases leading to misclassification for overweight and obesity, especially in certain segments of the population.
Abstract: OBJECTIVE: To examine the validity of self-reported weight and height and the resulting body mass index (BMI), and to explore the associations between demographic, socioeconomic, and health-related factors on the one hand and bias in self-reported weight and height on the other, in order to determine the groups most likely to exhibit bias. DESIGN: Prospective cohort study. SUBJECTS: 7350 middle-aged subjects, 5445 men and 1905 women, from the GAZEL cohort, who have been followed up since 1989 and work at the French national company Electricite De France–Gaz De France (EDF-GDF) in various occupations. MEASUREMENTS: Self-reported weight and height were based on information from yearly mailed questionnaires, and measured weight and height, used here as true values, were provided by occupational physicians from 1994 to 1997. Sex, age, marital status, education, occupation, history of ischemic heart disease, and treatment for cardiovascular risk factors were obtained from the mailed questionnaires or from data provided by the Company's personnel and medical departments. RESULTS: Strong correlations were found between measured and self-reported values, but self-reported weight and height displayed significant systematic errors. Weight was significantly underestimated for men (0.54 kg) and for women (0.85 kg), and height overestimated for men (0.38 cm) and women (0.40 cm). These biases led to significant underestimations of BMI (0.29 and 0.44 kg/m2 for men and women respectively). Consequently, the prevalence of overweight, defined as BMI>26.9 kg/m2 for women and BMI>27.2 kg/m2 for men, was also underestimated, by 13% for men and 17% for women. The five factors associated with bias in self-reported weight and height were: overweight status, end-digit preference, age, educational level and occupation. CONCLUSION: These findings suggest that self-reported weight and height should be treated with caution, because of biases leading to misclassification for overweight and obesity, especially in certain segments of the population.
TL;DR: A reduction in dietary fat without intentional restriction of energy intake causes weight loss, which is more substantial in heavier subjects.
Abstract: OBJECTIVES: Low-fat high-carbohydrate diets are recommended to prevent weight gain in normal weight subjects and reduce body weight in overweight and obese. However, their efficacy is controversial. We evaluated the efficacy of ad libitum low-fat diets in reducing body weight in non-diabetic individuals from the results of intervention trials. DESIGN: Studies were identified from a computerized search of the Medline database from January 1966 to July 1999 and other sources. Inclusion criteria were: controlled trials lasting more than 2 months comparing ad libitum low-fat diets as the sole intervention with a control group consuming habitual diet or a medium-fat diet ad libitum. MAIN OUTCOME MEASURES: Differences in changes in dietary fat intake, energy intake and body weight. Weighted mean differences for continuous data and 95% confidence intervals (CIs) were calculated. RESULTS: Two authors independently selected the studies meeting the inclusion criteria and extracted data from 16 trials (duration of 2–12 months) with 19 intervention groups, enrolling 1910 individuals. Fourteen were randomized. Weight loss was not the primary aim in 11 studies. Before the interventions the mean proportions of dietary energy from fat in the studies were 37.7% (95% CI, 36.9–38.5) in the low-fat groups, and 37.4% (36.4–38.4) in the control groups. The low-fat intervention produced a mean fat reduction of 10.2% (8.1–12.3). Low-fat intervention groups showed a greater weight loss than control groups (3.2 kg, 95% confidence interval 1.9–4.5 kg; P<0.0001), and a greater reduction in energy intake (1138 kJ/day, 95% confidence interval 564–1712 kJ/day, P=0.002). Having a body weight 10 kg higher than the average pre-treatment body weight was associated with a 2.6±0.8 kg (P=0.011) greater difference in weight loss. CONCLUSION: A reduction in dietary fat without intentional restriction of energy intake causes weight loss, which is more substantial in heavier subjects.
TL;DR: It is proposed that the green tea extract is effective in stimulating thermogenesis by relieving inhibition at different control points along the NA–cAMP axis, and a synergistic interaction between catechin-polyphenols and caffeine to augment and prolong sympathetic stimulation of thermogenesis could be of value in assisting the management of obesity.
Abstract: The thermogenic effect of tea is generally attributed to its caffeine content. We report here that a green tea extract stimulates brown adipose tissue thermogenesis to an extent which is much greater than can be attributed to its caffeine content per se, and that its thermogenic properties could reside primarily in an interaction between its high content in catechin-polyphenols and caffeine with sympathetically released noradrenaline (NA). Since catechin-polyphenols are known to be capable of inhibiting catechol-O-methyl-transferase (the enzyme that degrades NA), and caffeine to inhibit trancellular phosphodiesterases (enzymes that break down NA-induced cAMP), it is proposed that the green tea extract, via its catechin-polyphenols and caffeine, is effective in stimulating thermogenesis by relieving inhibition at different control points along the NA-cAMP axis. Such a synergistic interaction between catechin-polyphenols and caffeine to augment and prolong sympathetic stimulation of thermogenesis could be of value in assisting the management of obesity. International Journal of Obesity (2000) 24, 252-258
TL;DR: Examination of radiologic imaging techniques suggests that early-postmenopausal status is associated with a preferential increase in intra-abdominal fat that is independent of age and total body fat mass.
Abstract: OBJECTIVE: Preliminary studies suggest that the menopause transition is associated with deleterious changes in body composition and abdominal fat distribution. Limitations of the methodology used in these studies, however, render their conclusions controversial. Thus, the present study used radiologic imaging techniques to examine the effect of menopausal status on body composition and abdominal fat distribution. DESIGN: Cross-sectional. SUBJECTS: Fifty-three healthy, middle-aged, premenopausal women (mean±SD; 47±3 y) and 28 early-postmenopausal women (51±4 y). MEASUREMENTS: Total and regional body composition by dual energy X-ray absorptiometry and abdominal fat distribution by computed tomography. RESULTS: No differences in total body fat-free mass or appendicular skeletal muscle mass were noted between groups. In contrast, total body fat mass was 28% higher (23±7 vs 18±7 kg) and percentage fat 17% higher (35±6 vs 30±9%; both P<0.01) in postmenopausal women compared with premenopausal women. Postmenopausal women had a 49% greater intra-abdominal (88±32 vs 59±32 cm2; P<0.01) and a 22% greater abdominal subcutaneous fat area (277±93 vs 227±108 cm2; P<0.05) compared to premenopausal women. The menopause-related difference in intra-abdominal fat persisted (P<0.05) after statistical adjustment for age and total body fat mass, whereas no difference in abdominal subcutaneous fat was noted. A similar pattern of differences in total and abdominal adiposity was noted in sub-samples of pre- and postmenopausal women matched for age or fat mass. CONCLUSION: Our data suggest that early-postmenopausal status is associated with a preferential increase in intra-abdominal fat that is independent of age and total body fat mass.
TL;DR: Changes in childhood BMI were related to adult overweight and adiposity more so in females than males, however BMI patterns during and post-adolescence were more important than the BMI rebound for adulthood TBF and %BF status.
Abstract: BACKGROUND: Childhood overweight develops during ‘critical periods’, but the relationship of body mass index (BMI) patterns during ‘critical periods’ from childhood into adulthood with subsequent overweight and adiposity has not been previously investigated. BMI patterns during early childhood, pubescence and post-pubescence and their independent effects on overweight and body fatness at 35–45 y of age were examined along with birth weight and the effects of adult lifestyle factors. METHODS: BMI parameters describing the timing, velocity minimum (min) and maximum (max) values from 2 to 25 y of age were related to adulthood BMI values and total and percentage body fat (TBF, %BF) at 35–45 y. These data were from 180 males and 158 females in the Fels Longitudinal Study. RESULTS: There was no sex difference in the timing of BMI rebound, but the age of BMI maximum velocity and maximum BMI were both earlier in girls. Children with an earlier BMI rebound had larger BMI values at rebound and at maximum velocity. Children who reached maximum BMI at later age had larger maximum BMI values. Maximum BMI was a strong predictor for adult BMI and in females, a strong predictor of adulthood TBF and %BF. Maximum BMI was closely related to maximum BMI velocity in females and in males, BMI at maximum velocity is a strong predictor of TBF and %BF. CONCLUSIONS: Changes in childhood BMI were related to adult overweight and adiposity more so in females than males. BMI rebound is a significant important period related to overweight at 35–45 y in females but not in males. However BMI patterns during and post-adolescence were more important than the BMI rebound for adulthood TBF and %BF status. There is marked tracking in BMI from approximately 20 y into 35–45 y. The pattern of BMI changes from 2 to 25 y had stronger effects on subsequent adult overweight than birth weight and adult lifestyle variables.
TL;DR: G/T polymorphism in exon 2 was associated with neither plasma adiponectin concentrations nor the presence of obesity, and a subject carrying missense mutation (R112C) showed markedly low plasma adip onectin concentration.
Abstract: BACKGROUND: Adiponectin is a collagen-like plasma protein specifically synthesized in adipose tissue. Plasma adiponectin concentrations are decreased in obesity whereas it is adipose-specific. OBJECTIVE: To clarify the significance of the genetic variations in adiponectin gene on its plasma concentrations and obesity. SUBJECTS: Two hundred and nineteen unrelated adult Japanese subjects (123 men and 96 women, age: 20–83 y, BMI: 16–43 kg/m2) including 77 obese subjects (BMI>26.4 kg/m2). MEASUREMENT: Human adiponectin gene was isolated from PAC DNA pools. Mutations in the adiponectin gene were screened by direct sequencing or restriction-fragment polymorphism. The levels of plasma adiponectin were determined by the enzyme-linked immunosorbent assay (ELISA). RESULTS: Adiponectin gene spanned 17 kb on chromosome 3q27, consisting of three exons and two introns. Within 2.1 kb of the 5′-flanking region, there were two octamer elements present in the promoter of adipsin. Two nucleotide changes were identified. One was a polymorphism (G/T) occurring in exon 2, and the other was a missense mutation (R112C) in exon 3. The mean plasma adiponectin levels of the subjects carrying G allele were low (G/G: 4.5 μg/ml; G/T: 5.9 μg/ml; and T/T: 6.3 μg/ml), but were not statistically significant. The allelic frequency between the obese and the non-obese showed no significant difference. The subject carrying R112C mutation showed markedly low concentration of plasma adiponectin. CONCLUSION: Two nucleotide changes have been identified in the adiponectin gene. G/T polymorphism in exon 2 was associated with neither plasma adiponectin concentrations nor the presence of obesity. A subject carrying missense mutation (R112C) showed markedly low plasma adiponectin concentration.
TL;DR: In overweight and obese boys and girls there is a mismatch between body weight and bone development during growth: their bone mass and bone area are low for their body weight.
Abstract: OBJECTIVES: To determine whether girls and boys categorized from body mass index (BMI) values as overweight or obese for their age have lower bone mineral content (BMC) or lower bone area in relation to total body weight than children of normal adiposity. DESIGN: Cross-sectional study in a university bone research unit. SUBJECTS: Two hundred girls and 136 boys aged 3–19 y recruited from the general population by advertisement. MEASUREMENTS: Total body BMC (g) and bone area (cm2) measured by dual energy X-ray absorptiometry (DXA) in relation to body weight (kg), lean tissue mass (kg) and fat mass (kg) in boys and girls of three different BMI percentile groupings: normal weight (BMI<85th percentile); overweight (85 to 94th BMI percentile); obese (≥95th BMI percentile). RESULTS: Obese children had higher BMC, bone area, and fat mass for chronological age than those of normal body weight (P<0.001). In spite of this the observed values for age-adjusted total body BMC and bone area relative to body weight were each lower than predicted values, in both overweight and obese children (2.5–10.1% less, P<0.05) than in children of lower adiposity. CONCLUSION: In overweight and obese boys and girls there is a mismatch between body weight and bone development during growth: their bone mass and bone area are low for their body weight.
TL;DR: Time spent watching television and a low physical activity at work were related to obesity in adults in Spain, and the inverse association between obesity and sleep duration deserves further research.
Abstract: OBJECTIVE: To analyse the association of time watching television (TV) and physical activity with obesity in the Mediterranean area of Spain with the highest prevalence of obesity. DESIGN: Cross-sectional study. SETTING: Valencia Region in Spain. PARTICIPANTS: A representative sample of 814 men and 958 women, aged 15 y and older, participating in a Health and Nutrition Survey conducted in 1994. MEASUREMENTS: Height and weight were directly measured during home interviews. The outcome measure was obesity, defined as a body mass index ≥30 kg/m2. Covariates were self-reported hours of TV viewing, physical activity habits, sleeping duration, age, gender, educational level, smoking and marital status. Prevalence odds ratios (POR) estimated by logistic regression were used as effect measures. RESULTS: Obese people reported to spend more time watching TV (mean±s.d.: 3.6±1.5 h/day) than non-obese ones (3.0±1.4 h/day), and less sleeping time. In multivariate analysis, obesity was associated with TV viewing, sleeping time and physical activity at work. People watching TV ≥4 h/day showed a higher adjusted prevalence odds ratio of obesity, POR=2.38 (95% confidence interval, 1.54–3. 69), compared with those watching TV ≤1 h/day. People who reported to sleep ≥9 h/day presented a lower POR of obesity than those sleeping ≤6 h/day, POR=0.43 (0.27–0.67). Statistically significant dose–responses were observed for both associations, so that the prevalence odds ratio of obesity was 30% higher for each hour of increased TV viewing and 24% lower for each additional hour of sleeping time. In addition, the prevalence of obesity was lowest among single people, those more physically active at work, and those with a high educational level. CONCLUSION: Time spent watching television and a low physical activity at work were related to obesity in adults. The inverse association between obesity and sleep duration deserves further research.
TL;DR: Extremely obese adolescents and young adults who seek long-term inpatient treatment have a high lifetime prevalence for affective, anxiety, somatoform and eating disorders.
Abstract: OBJECTIVE: To compare rates of DSM-IV psychiatric disorders between (1) a clinical study group of extremely obese adolescents and young adults, (2) gender-matched population-based obese controls and (3) a population-based control group of the same age range. DESIGN: Rates of psychiatric disorders were assessed in (1) the clinical study group of obese adolescents and (2) the population based sample of obese adolescents, and compared to (3) a large population-based control group using a standardized psychiatric interview. SUBJECTS: (1) Clinical study group: 30 female and 17 male extremely obese adolescents and young adults (age range: 15–21 y; mean BMI:42.4 kg/m2). (2) Thirty females and 17 males with the highest BMI (age range 15–21 y; mean BMI:29.8 kg/m2) of a population-based control group encompassing 1655 (805 males) adolescents and young adults. (3) The population based control group excluding the 30 females and 17 males with the highest BMI (n=1608; 788 males). MEASUREMENTS: Munich-Composite International Diagnostic Interview (M-CIDI) allowing for DSM-IV diagnoses. RESULTS: High rates of mood, anxiety, somatoform and eating disorders were detected in the clinical sample of obese adolescents which exceeded those observed in population controls (all P-values<0.01). Rates between population-based obese adolescents and young adults and population controls did not differ. In most patients the psychiatric disorders set in after onset of obesity. 57% and 35% of the female and male patients, respectively, reported eating binges with lack of control. However, less than one-half of these patients qualified for a DSM-IV diagnosis of an eating disorder. CONCLUSIONS: Extremely obese adolescents and young adults who seek long-term inpatient treatment have a high lifetime prevalence for affective, anxiety, somatoform and eating disorders. Because the mean BMI of the clinical study group was considerably higher than that of the obese population controls, we were not able to clarify whether the high rate of psychopathology in the study group was related to the extreme obesity or to their treatment-seeking behavior.
TL;DR: The major influence of body weight onVO2max is explained by FFM; FM does not have any effect on VO2max.
Abstract: OBJECTIVE: The objective of this study was to examine the influence of body weight and body composition on aspects of aerobic fitness. Our hypothesis was that increased body weight, specifically increased fat mass (FM), would not limit VO2max relative to fat-free mass (FFM), but would reduce maximal and sub-maximal VO2max relative to body weight. DESIGN: We used data from two ongoing studies. In Study 1 a cross-sectional analysis of 129 children across a wide spectrum of body composition was performed. In Study 2 we examined data from 31 overweight women before and after weight loss. METHODS: VO2max was measured using a treadmill test. Sub-maximal aerobic capacity was evaluated with respiratory exchange ratio (RER), heart-rate (HR), and oxygen uptake relative to VO2max at a given workload (%VO2max). Body composition was assessed using dual energy X-ray absorptiometry (DXA) (Study 1) and a four-compartment model (Study 2). RESULTS: In Study 1, FFM was the strongest determinant of VO2max (r=0.87; P<0.0001). After adjusting for FFM, there was no significant influence of FM on VO2max. After separating children into lean and obese sub-groups, absolute VO2max was significantly higher in the obese (1.24±0.27 vs 1.56±0.40) and VO2max relative to body weight was significantly lower (44.2±3.2 vs 32.0±4.1 ml/(kg-min)), whereas there was no significant difference when expressed relative to FFM (57.9±5.8 vs 59.2±4.9 ml/(kgFFM-min)). Sub-maximal aerobic capacity was significantly lower in the obese children, as indicated by a higher HR and %VO2max; time to exhaustion was significantly lower in the obese children (15.3±2.9 vs 11.1±2.1 min). In Study 2, FFM was also the strongest determinant of VO2max before and after weight loss. The relationship between VO2max and FFM was identical before and after weight loss so that VO2max relative to FFM was identical before and after weight loss (43.8±4.9 vs 45.5±6.4 ml/(kgFFM-min)). However, sub-maximal aerobic capacity was lower in the obese state, as indicated by a significantly higher RER (0.85±0.06 vs 0.79±0.05), HR (124±14 vs 102±11 bpm), and %VO2max (44% vs 36%). CONCLUSION: The major influence of body weight on VO2max is explained by FFM; FM does not have any effect on VO2max. Fatness and excess body weight do not necessarily imply a reduced ability to maximally consume oxygen, but excess fatness does have a detrimental effect on submaximal aerobic capacity. Thus, fatness and VO2max should be considered independent entities.
TL;DR: In this article, the effect of food source on body mass index (BMI) while accounting for other factors has been shown to affect obesity in a nationally representative sample of the US population.
Abstract: OBJECTIVE: To determine if the source from which food is obtained has contributed to the increased obesity of the US population, while controlling for demographic, lifestyle and regional factors. METHODS: Multiple regression was used to estimate the effect of food source on body mass index (BMI) while accounting for other factors which have been shown to affect obesity in a nationally representative sample of the US population. SAMPLE: This study used secondary data from the 1994–1996 Continuing Survey of Food Intake by Individuals (CSFII). The CSFII is a nationally representative sample of 16,103 individuals, obtaining for each respondent 24 h recalls of all food intake on two nonconsecutive days as well as demographics and information on lifestyle choices. RESULTS: For a large number of demographic and lifestyle factors, our results support those which have previously been found to contribute to increased overweight. Our contribution is to examine whether the source from which food is obtained also contributes to increased overweight. Our evidence suggests that this is the case. The average height for males in our sample was 1.77 m. For two such males, one who ate food away from home (FAFH) during the previous 24 h period and the other who did not, results suggest that the first will be about 1 kg heavier, all other factors being equal. For two females of average height (1.63 m) the same is true for those who ate fast food, but not at restaurants. In all cases, except females who ate at restaurants, the effects are significant in the regression (P<0.05). CONCLUSION: The trends in both increased US obesity and in increased consumption of FAFH are unlikely to be coincidental. FAFH, and particularly fast food consumption, are likely to be contributing factors to increased obesity.
TL;DR: With approximately half the Australian adult population overweight or obese, these findings indicate that public health strategies to reduce overweight and prevent weight gain may need to focus on reducing sedentary behaviours such as television viewing in addition to increasing physical activity.
Abstract: OBJECTIVES: To investigate the effect of physical activity on the association between television viewing and overweight (body mass index (BMI) ≥25 kg/m2). DESIGN: Cross-sectional study administered by interview to adults randomly selected from the electronic white pages. SUBJECTS: 3392 adults (64% response rate) from a representative population sample in the State of New South Wales, Australia. MEASUREMENTS: Self-reported height and weight, two-week leisure-time physical activity recall, one-week average television viewing recall. RESULTS: BMI and physical activity patterns were both associated with hours of television watched. Compared to those participants who reported watching less than one hour of television per day, those watching 1 to 2.5 hours were 93% more likely to be overweight (BMI≥25 kg/m2), those watching 2.5 to 4 hours were 183% more likely to be overweight, those watching more than 4 hours per day were four times more likely to be overweight. Physical activity was not directly associated with being overweight, but an interaction between activity and television watching was present. Respondents in the low, moderate and high physical activity categories who reported watching more than 4 hours of television per day were twice as likely to be overweight compared to those who watched less than one hour of television per day, irrespective of physical activity participation. CONCLUSIONS: With approximately half the Australian adult population overweight or obese, these findings indicate that public health strategies to reduce overweight and prevent weight gain may need to focus on reducing sedentary behaviours such as television viewing in addition to increasing physical activity.
TL;DR: Obesity does not appear to be a public health problem among preschool children in Asia and Sub-Saharan Africa and in a number of countries in Latin America and the Caribbean, the Middle East and North Africa, and the region of Central Eastern Europe/Commonwealth of Independent States, levels are as high as in the United States.
Abstract: OBJECTIVES: To estimate levels and trends in overweight and obesity in preschool children from developing countries; to study how overweight varies by the educational level of the mother, by urban or rural residence, and by gender; to investigate how these relationships are related to the gross national product (GNP). DESIGN: 71 national nutrition surveys since 1986 from 50 countries were used. SUBJECTS: 150,482 children 12 to 60 months from the most recent survey from each country were the primary sample. MEASUREMENTS: Overweight and obesity were defined as weight-for-height (>1 or >2 s.d., respectively) of the WHO/NCHS reference curves. Stunting was <−2 s.d. of the same reference. Urban was as defined in each of the surveys and higher education was defined as at least one year of secondary schooling or higher. RESULTS: 32 of 50 countries had a prevalence of obesity below 2.3%, the value in the reference population. The prevalences of overweight and obesity were lowest in Asia and in Sub-Saharan Africa. In 17 countries with serial data, no consistent regional trends could be detected. Overweight was more common in urban areas, in children of mothers with higher education, and in girls; these relationships did not differ by GNP but GNP was related negatively to stunting and positively to overweight. CONCLUSIONS: Obesity does not appear to be a public health problem among preschool children in Asia and Sub-Saharan Africa. In a number of countries in Latin America and the Caribbean, the Middle East and North Africa, and the region of Central Eastern Europe/Commonwealth of Independent States, levels are as high as in the United States.
TL;DR: Interventions to prevent weight gain exhibited various degrees of effectiveness, and future interventions might be more effective if they were explicitly based on methods of behaviour change that have been shown to work in other contexts.
Abstract: OBJECTIVE: To identify and review published interventions aimed at the prevention of weight gain. DESIGN: A systematic review of published interventions aimed at the prevention of weight gain. METHODS: Search strategies—we searched eight databases, manually checked reference lists and contacted authors. Inclusion and exclusion criteria—studies of any design, in which participants were selected regardless of weight or age, were included. Interventions targeting a specific subgroup, multifactorial interventions, interventions aimed at weight loss, and those with an ambiguous aim were excluded. Data extraction—data were extracted on behaviours targeted for change, psychological model, behaviour change methods and modes of delivery, methodological quality, characteristics of participants, and outcomes related to body weight and self-reported diet and physical activity. Classification and validation—a taxonomy of behaviour change programmes was developed and used for classification of underlying model, behaviour change methods, and modes of delivery. The data extraction and subsequent classification were independently validated. RESULTS: Eleven publications were included, describing five distinct interventions in schools and four in the wider community. Where diet and physical activity were described, positive effects were usually obtained, but all were measured by self-report. Effects on weight were mixed but follow-up was generally short. Smaller effects on weight gain were found among low-income participants, students and smokers. Many participants in the community-based studies were overweight or obese. Study dropout was higher among thinner and lower-income subjects. CONCLUSION: Interventions to prevent weight gain exhibited various degrees of effectiveness. Definite statements about the elements of the interventions that were associated with increased effect size cannot be made as only one of the five studies that involved an RCT design reported a significant effect on weight. This intervention involved a correspondence programme and a mix of behaviour change methods including goal setting, self-monitoring and contingencies. Future interventions might be more effective if they were explicitly based on methods of behaviour change that have been shown to work in other contexts. Effective interventions would be more easily replicated if they were explicitly described. Effectiveness might be more precisely demonstrated if more objective measures of physical activity and diet were used, and if the follow-up was over a longer period.
TL;DR: While these data find low proportions of Asian Americans overweight at present, they also imply the proportion will increase with more US-born Asian Americans and longer duration in the US.
Abstract: OBJECTIVE: To examine body mass index (BMI) and the proportion overweight and obese among adults age 18–59 in the six largest Asian American ethnic groups (Chinese, Filipino, Asian Indian, Japanese, Korean, Vietnamese), and investigate whether BMI varies by nativity (foreign- vs native-born), years in US, or socioeconomic status. DESIGN: Cross-sectional interview data were pooled from the 1992–1995 National Health Interview Survey (NHIS). SUBJECTS: 254,153 persons aged 18–59 included in the 1992–1995 NHIS. Sample sizes range from 816 to 1940 for each of six Asian American ethnic groups. MEASUREMENTS: Self-reported height and weight used to calculate BMI and classify individuals as overweight (BMI≥25 kg/m2) or obese (BMI≥30 kg/m2), age, sex, years in the US, household income and household size. RESULTS: For men, the percentage overweight ranges from 17% of Vietnamese to 42% of Japanese, while the total male population is 57% overweight. For women, the percentage overweight ranges from 9% of Vietnamese and Chinese to 25% of Asian Indians, while the total female population is 38% overweight. The percentage of Asian Americans classified as obese is very low. Adjusted for age and ethnicity, the odds ratio for obese is 3.5 for women and 4.0 for men for US - vs foreign-born. Among the foreign-born, more years in the US is associated with higher risk of being overweight or obese. The association between household income for women is similar for US-born Asian Americans and Whites and Blacks, but is much weaker for foreign-born Asian Americans. CONCLUSIONS: While these data find low proportions of Asian Americans overweight at present, they also imply the proportion will increase with more US-born Asian Americans and longer duration in the US.
TL;DR: Screening for childhood obesity using the BMI is specific, and can have moderately high sensitivity if an appropriate cut-off is chosen, and new recommendations based on the IOTF approach to defining childhood obesity are associated with lower sensitivity, and sensitivity differs between boys and girls.
Abstract: OBJECTIVE: To assess the ability of simple definitions of BMI to successfully screen for children with high body fatness. DESIGN: We determined the sensitivity and specificity of the body mass index (BMI) by testing its ability to correctly identify children with high body fat percentage. Receiver operator characteristic (ROC) analyses were carried out using the top 5% of body fat percentage to define children as obese (true positives). SUBJECTS: Representative sample of 4175 7 y-old (88–92 month-old) children (2120 boys; 2055 girls) participating in the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC). RESULTS: The current obesity definition based on BMI (95th centile) had moderately high sensitivity (88%) and high specificity (94%). Sensitivity and specificity did not differ significantly between boys and girls. The ROC analysis showed that lower cut-offs applied to the BMI improved sensitivity with no marked loss of specificity: the optimum combination of sensitivity (92%) and specificity (92%) was at a BMI cut-off equivalent to the 92nd centile. Sensitivity of BMI using the new International Obesity Task Force (IOTF) cut-off for obesity was much lower, and differed significantly (P<0.001) between boys (46%) and girls (72%). CONCLUSIONS: Screening for childhood obesity using the BMI is specific, and can have moderately high sensitivity if an appropriate cut-off is chosen. New recommendations based on the IOTF approach to defining childhood obesity are associated with lower sensitivity, and sensitivity differs between boys and girls.
TL;DR: Orlistat was well tolerated and offered a promising new approach to the long-term management of obesity, and produced greater and more frequent significant weight loss than placebo during 1 y of treatment.
Abstract: OBJECTIVE: To assess the efficacy and tolerability of orlistat (Xenical®) in producing and maintaining weight loss over a 12-month period. DESIGN: Patients were randomized to double-blind treatment with either orlistat 120 mg or placebo three times daily, in conjunction with a low-energy diet, for 12 months. SETTING: Five centres in the UK. SUBJECTS: 228 obese adult patients with body mass index between 30 and 43 kg/m2 and mean weight 97 kg (range 74–144 kg). INTERVENTIONS: All patients were prescribed a low-energy diet, providing 30% of energy from fat, designed to produce an individually tailored energy deficit of approximately 600 kcal/day, for a run-in period of 4 weeks and then 12 months, plus orlistat 120 mg or placebo three times daily. MAIN OUTCOME MEASURES: Change in body weight (the primary efficacy parameter), waist circumference and adverse events were reviewed regularly, together with serum lipids, insulin, glucose and plasma levels of fat-soluble vitamins and β carotene. RESULTS: Based on an intent-to-treat analysis, after 1 y of treatment patients receiving orlistat had lost an average of 8.5% of their initial body weight compared with 5.4% for placebo-treated patients; 35% of the orlistat group lost at least 5% of body weight compared with 21% of the placebo group (P<0.05), and 28% and 17%, respectively (P=0.04) lost at least 10% of body weight. Orlistat-treated patients showed significant decreases (P<0.05) in serum levels of total cholesterol, low density lipoprotein cholesterol, and in the low density lipoprotein:high density lipoprotein ratio in comparison with placebo. Both groups had similar adverse-event profiles, except for gastrointestinal events, which were 26% more frequent in the orlistat group but were mostly mild and transient. To maintain normal plasma levels of fat-soluble vitamins, supplements of vitamins A, D and E were given to 1.8%, 8.0% and 3.6%, respectively, of orlistat-treated patients, compared with 0.9% of placebo-treated patients for each vitamin type. After 1 y, the decrease in vitamin E and β carotene was significantly greater in orlistat-treated patients compared with those receiving placebo (P<0.001). No significant change was found in the mean vitamin E:total cholesterol ratio in either group after 52 weeks. Conclusions: Orlistat, in conjunction with a low-energy diet, produced greater and more frequent significant weight loss than placebo during 1 y of treatment. One-third of orlistat-treated patients achieved clinically relevant weight loss (≥5% initial body weight). There was also an improvement in relevant serum lipid parameters. Fat-soluble vitamin supplements may be required during chronic therapy. Orlistat was well tolerated and offers a promising new approach to the long-term management of obesity.
TL;DR: Prudent substitution therapy with L-thyroxine is indicated in patients with both overt and subclinical hypothyroidism, with or without angina, to counteract the cardiovascular risk resulting from hyper-dyslipidemia.
Abstract: Thyroid hormones influence all major metabolic pathways. Their most obvious and well-known action is an increase in basal energy expenditure obtained acting on protein, carbohydrate and lipid metabolism. With specific regard to lipid metabolism, thyroid hormones affect synthesis, mobilization and degradation of lipids, although degradation is influenced more than synthesis. The main and best-known effects on lipid metabolism include: (a) enhanced utilization of lipid substrates; (b) increase in the synthesis and mobilization of triglycerides stored in adipose tissue; (c) increase in the concentration of non-esterified fatty acids (NEFA); and (d) increase of lipoprotein-lipase activity. While severe hypothyroidism is usually associated with an increased serum concentration of total cholesterol and atherogenic lipoproteins, the occurrence of acute myocardial infarction (AMI) in hypothyroid patients is not frequent. However, hypothyroid patients appear to have an increased incidence of residual myocardial ischemia following AMI. Even in subclinical hypothyroidism, which is characterized by raised serum TSH levels with normal serum thyroid hormone concentrations, mild hyperlipidemia is present and may contribute to an increased risk of atherogenesis. Prudent substitution therapy with L-thyroxine is indicated in patients with both overt and subclinical hypothyroidism, with or without angina, to counteract the cardiovascular risk resulting from hyper-dyslipidemia.
TL;DR: The apparent U-shaped association between BMI and total mortality may be the result of compound risk functions from body fat and fat-free mass.
Abstract: Mortality associated with body fat, fat-free mass and body mass index among 60-year-old Swedish men—a 22-year follow-up. The study of men born in 1913