Showing papers on "Body mass index published in 2011"

Systematic review of sedentary behaviour and health indicators in school-aged children and youth

Abstract: Accumulating evidence suggests that, independent of physical activity levels, sedentary behaviours are associated with increased risk of cardio-metabolic disease, all-cause mortality, and a variety of physiological and psychological problems. Therefore, the purpose of this systematic review is to determine the relationship between sedentary behaviour and health indicators in school-aged children and youth aged 5-17 years. Online databases (MEDLINE, EMBASE and PsycINFO), personal libraries and government documents were searched for relevant studies examining time spent engaging in sedentary behaviours and six specific health indicators (body composition, fitness, metabolic syndrome and cardiovascular disease, self-esteem, pro-social behaviour and academic achievement). 232 studies including 983,840 participants met inclusion criteria and were included in the review. Television (TV) watching was the most common measure of sedentary behaviour and body composition was the most common outcome measure. Qualitative analysis of all studies revealed a dose-response relation between increased sedentary behaviour and unfavourable health outcomes. Watching TV for more than 2 hours per day was associated with unfavourable body composition, decreased fitness, lowered scores for self-esteem and pro-social behaviour and decreased academic achievement. Meta-analysis was completed for randomized controlled studies that aimed to reduce sedentary time and reported change in body mass index (BMI) as their primary outcome. In this regard, a meta-analysis revealed an overall significant effect of -0.81 (95% CI of -1.44 to -0.17, p = 0.01) indicating an overall decrease in mean BMI associated with the interventions. There is a large body of evidence from all study designs which suggests that decreasing any type of sedentary time is associated with lower health risk in youth aged 5-17 years. In particular, the evidence suggests that daily TV viewing in excess of 2 hours is associated with reduced physical and psychosocial health, and that lowering sedentary time leads to reductions in BMI.

Childhood Adiposity, Adult Adiposity, and Cardiovascular Risk Factors

Abstract: Background Obesity in childhood is associated with increased cardiovascular risk. It is uncertain whether this risk is attenuated in persons who are overweight or obese as children but not obese as adults. Methods We analyzed data from four prospective cohort studies that measured childhood and adult body-mass index (BMI, the weight in kilograms divided by the square of the height in meters). The mean length of follow-up was 23 years. To define high adiposity status, international age-specific and sex-specific BMI cutoff points for overweight and obesity were used for children, and a BMI cutoff point of 30 was used for adults. Results Data were available for 6328 subjects. Subjects with consistently high adiposity status from childhood to adulthood, as compared with persons who had a normal BMI as children and were nonobese as adults, had an increased risk of type 2 diabetes (relative risk, 5.4; 95% confidence interval [CI], 3.4 to 8.5), hypertension (relative risk, 2.7; 95% CI, 2.2 to 3.3), elevated low-...

A Better Index of Body Adiposity

Abstract: Obesity is a growing problem in the United States and throughout the world. It is a risk factor for many chronic diseases. The BMI has been used to assess body fat for almost 200 years. BMI is known to be of limited accuracy, and is different for males and females with similar %body adiposity. Here, we define an alternative parameter, the body adiposity index (BAI = ((hip circumference)/((height)1.5) − 18)). The BAI can be used to reflect %body fat for adult men and women of differing ethnicities without numerical correction. We used a population study, the “BetaGene” study, to develop the new index of body adiposity. %Body fat, as measured by the dual-energy X-ray absorptiometry (DXA), was used as a “gold standard” for validation. Hip circumference (R = 0.602) and height (R = −0.524) are strongly correlated with %body fat and therefore chosen as principal anthropometric measures on which we base BAI. The BAI measure was validated in the “Triglyceride and Cardiovascular Risk in African-Americans (TARA)” study of African Americans. Correlation between DXA-derived %adiposity and the BAI was R = 0.85 for TARA with a concordance of C_b = 0.95. BAI can be measured without weighing, which may render it useful in settings where measuring accurate body weight is problematic. In summary, we have defined a new parameter, the BAI, which can be calculated from hip circumference and height only. It can be used in the clinical setting even in remote locations with very limited access to reliable scales. The BAI estimates %adiposity directly.

Association between Body-Mass Index and Risk of Death in More Than 1 Million Asians

Abstract: A b s t r ac t Background Most studies that have evaluated the association between the body-mass index (BMI) and the risks of death from any cause and from specific causes have been conducted in populations of European origin. Methods We performed pooled analyses to evaluate the association between BMI and the risk of death among more than 1.1 million persons recruited in 19 cohorts in Asia. The analyses included approximately 120,700 deaths that occurred during a mean follow-up period of 9.2 years. Cox regression models were used to adjust for confounding factors. Results In the cohorts of East Asians, including Chinese, Japanese, and Koreans, the lowest risk of death was seen among persons with a BMI (the weight in kilograms divided by the square of the height in meters) in the range of 22.6 to 27.5. The risk was elevated among persons with BMI levels either higher or lower than that range — by a factor of up to 1.5 among those with a BMI of more than 35.0 and by a factor of 2.8 among those with a BMI of 15.0 or less. A similar U-shaped association was seen between BMI and the risks of death from cancer, from cardiovascular diseases, and from other causes. In the cohorts comprising Indians and Bangladeshis, the risks of death from any cause and from causes other than cancer or cardiovascular disease were increased among persons with a BMI of 20.0 or less, as compared with those with a BMI of 22.6 to 25.0, whereas there was no excess risk of either death from any cause or cause-specific death associated with a high BMI. Conclusions Underweight was associated with a substantially increased risk of death in all Asian populations. The excess risk of death associated with a high BMI, however, was seen among East Asians but not among Indians and Bangladeshis.

Assessing Adiposity A Scientific Statement From the American Heart Association

Abstract: The prevalence of obesity in the United States and the world has risen to epidemic/pandemic proportions. This increase has occurred despite great efforts by healthcare providers and consumers alike to improve the health-related behaviors of the population and a tremendous push from the scientific community to better understand the pathophysiology of obesity. This epidemic is all the more concerning given the clear association between excess adiposity and adverse health consequences such as cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). The risks associated with overweight/obesity are primarily related to the deposition of adipose tissue, which leads to excess adiposity or body fatness. Furthermore, weight loss, specifically loss of body fat, is associated with improvement in obesity-related comorbidities. Before weight loss interventions can be recommended, however, patients must be assessed for their adiposity-related risk. Unfortunately, healthcare providers and systems have not done a good job of assessing for excess adiposity even in its simplest form, such as measuring body mass index (BMI). It is for these reasons that we must emphasize the importance of assessing adiposity in clinical practices. Although it can be argued that the entire population should be targeted as an important public health issue with a goal of prevention of weight gain and obesity, there are currently so many “at risk” individuals that simple strategies to identify and treat those individuals are necessary. We must identify those individuals at highest risk of comorbidities in order to identify those who might benefit the most from aggressive weight management. This scientific statement will first briefly review the epidemiology of obesity and its related comorbidities, supporting the need for improved assessment of adiposity in daily clinical practice. This will be followed by a discussion of some of the challenges and issues associated with assessing adiposity and then by a review …

Interventions for preventing obesity in children (Review)

Abstract: Background Prevention of childhood obesity is an international public health priority given the significant impact of obesity on acute and chronic diseases, general health, development and well-being. The international evidence base for strategies that governments, communities and families can implement to prevent obesity, and promote health, has been accumulating but remains unclear. Objectives This review primarily aims to update the previous Cochrane review of childhood obesity prevention research and determine the effectiveness of evaluated interventions intended to prevent obesity in children, assessed by change in Body Mass Index (BMI). Secondary aims were to examine the characteristics of the programs and strategies to answer the questions "What works for whom, why and for what cost?" Search methods The searches were re-run in CENTRAL, MEDLINE, EMBASE, PsychINFO and CINAHL in March 2010 and searched relevant websites. Non-English language papers were included and experts were contacted. Selection criteria The review includes data from childhood obesity prevention studies that used a controlled study design (with or without randomisation). Studies were included if they evaluated interventions, policies or programs in place for twelve weeks or more. If studies were randomised at a cluster level, 6 clusters were required. Data collection and analysis Two review authors independently extracted data and assessed the risk of bias of included studies. Data was extracted on intervention implementation, cost, equity and outcomes. Outcome measures were grouped according to whether they measured adiposity, physical activity (PA)-related behaviours or diet-related behaviours. Adverse outcomes were recorded. A meta-analysis was conducted using available BMI or standardised BMI (zBMI) score data with subgroup analysis by age group (0-5, 6-12, 13-18 years, corresponding to stages of developmental and childhood settings). Main results This review includes 55 studies (an additional 36 studies found for this update). The majority of studies targeted children aged 6-12 years. The meta-analysis included 37 studies of 27,946 children and demonstrated that programmes were effective at reducing adiposity, although not all individual interventions were effective, and there was a high level of observed heterogeneity (I2=82%). Overall, children in the intervention group had a standardised mean difference in adiposity (measured as BMI or zBMI) of -0.15kg/m2 (95% confidence interval (CI): -0.21 to -0.09). Intervention effects by age subgroups were -0.26kg/m2 (95% CI:-0.53 to 0.00) (0-5 years), -0.15kg/m2 (95% CI -0.23 to -0.08) (6-12 years), and -0.09kg/m2 (95% CI -0.20 to 0.03) (13-18 years). Heterogeneity was apparent in all three age groups and could not explained by randomisation status or the type, duration or setting of the intervention. Only eight studies reported on adverse effects and no evidence of adverse outcomes such as unhealthy dieting practices, increased prevalence of underweight or body image sensitivities was found. Interventions did not appear to increase health inequalities although this was examined in fewer studies. Authors' conclusions We found strong evidence to support beneficial effects of child obesity prevention programmes on BMI, particularly for programmes targeted to children aged six to 12 years. However, given the unexplained heterogeneity and the likelihood of small study bias, these findings must be interpreted cautiously. A broad range of programme components were used in these studies and whilst it is not possible to distinguish which of these components contributed most to the beneficial effects observed, our synthesis indicates the following to be promising policies and strategies: · school curriculum that includes healthy eating, physical activity and body image · increased sessions for physical activity and the development of fundamental movement skills throughout the school week · improvements in nutritional quality of the food supply in schools · environments and cultural practices that support children eating healthier foods and being active throughout each day · support for teachers and other staff to implement health promotion strategies and activities (e.g. professional development, capacity building activities) · parent support and home activities that encourage children to be more active, eat more nutritious foods and spend less time in screen based activities However, study and evaluation designs need to be strengthened, and reporting extended to capture process and implementation factors, outcomes in relation to measures of equity, longer term outcomes, potential harms and costs. Childhood obesity prevention research must now move towards identifying how effective intervention components can be embedded within health, education and care systems and achieve long term sustainable impacts.

Rotating night shift work and risk of type 2 diabetes: two prospective cohort studies in women.

Abstract: Background Rotating night shift work disrupts circadian rhythms and has been associated with obesity, metabolic syndrome, and glucose dysregulation. However, its association with type 2 diabetes remains unclear. Therefore, we aimed to evaluate this association in two cohorts of US women. Methods and Findings We followed 69,269 women aged 42–67 in Nurses' Health Study I (NHS I, 1988–2008), and 107,915 women aged 25–42 in NHS II (1989–2007) without diabetes, cardiovascular disease, and cancer at baseline. Participants were asked how long they had worked rotating night shifts (defined as at least three nights/month in addition to days and evenings in that month) at baseline. This information was updated every 2–4 years in NHS II. Self-reported type 2 diabetes was confirmed by a validated supplementary questionnaire. We documented 6,165 (NHS I) and 3,961 (NHS II) incident type 2 diabetes cases during the 18–20 years of follow-up. In the Cox proportional models adjusted for diabetes risk factors, duration of shift work was monotonically associated with an increased risk of type 2 diabetes in both cohorts. Compared with women who reported no shift work, the pooled hazard ratios (95% confidence intervals) for participants with 1–2, 3–9, 10–19, and ≥20 years of shift work were 1.05 (1.00–1.11), 1.20 (1.14–1.26), 1.40 (1.30–1.51), and 1.58 (1.43–1.74, p-value for trend <0.001), respectively. Further adjustment for updated body mass index attenuated the association, and the pooled hazard ratios were 1.03 (0.98–1.08), 1.06 (1.01–1.11), 1.10 (1.02–1.18), and 1.24 (1.13–1.37, p-value for trend <0.001). Conclusions Our results suggest that an extended period of rotating night shift work is associated with a modestly increased risk of type 2 diabetes in women, which appears to be partly mediated through body weight. Proper screening and intervention strategies in rotating night shift workers are needed for prevention of diabetes. Please see later in the article for the Editors' Summary

Body mass index in midlife and late-life as a risk factor for dementia: a meta-analysis of prospective studies.

Abstract: The relationship between body mass index (BMI) (in midlife and late-life) and dementia was investigated in meta-analyses of 16 articles reporting on 15 prospective studies. Follow-ups ranged from 3.2 to 36.0 years. Meta-analyses were conducted on samples including 25 624 participants evaluated for Alzheimer's disease (AD), 15 435 participants evaluated for vascular dementia (VaD) and 30 470 followed for any type of dementia (Any Dementia). Low BMI in midlife was associated with 1.96 [95% confidence interval (CI): 1.32, 2.92] times the risk of developing AD. The pooled relative risks for AD, VaD and Any Dementia for overweight BMI in midlife compared with normal BMI were 1.35 (95% CI:1.19, 1.54), 1.33 (95% CI: 1.02, 1.75) and 1.26 (95% CI: 1.10, 1.44), respectively. The pooled relative risks of AD and Any Dementia for obese BMI in midlife compared to normal BMI were 2.04 (95% CI: 1.59, 2.62) and 1.64 (95% CI: 1.34, 2.00), respectively. Continuous BMI in late-life was not associated with dementia. Small numbers of studies included in pooled analyses reduce generalizability of findings, and emphasize the need for publication of additional findings. We conclude that underweight, overweight and obesity in midlife increase dementia risk. Further research evaluating late-life BMI and dementia is required.

Adolescent BMI trajectory and risk of diabetes versus coronary disease.

Abstract: BackgroundThe association of body-mass index (BMI) from adolescence to adulthood with obesity-related diseases in young adults has not been completely delineated. MethodsWe conducted a prospective study in which we followed 37,674 apparently healthy young men for incident angiography-proven coronary heart disease and diabetes through the Staff Periodic Examination Center of the Israeli Army Medical Corps. The height and weight of participants were measured at regular intervals, with the first measurements taken when they were 17 years of age. ResultsDuring approximately 650,000 person-years of follow-up (mean follow-up, 17.4 years), we documented 1173 incident cases of type 2 diabetes and 327 of coronary heart disease. In multivariate models adjusted for age, family history, blood pressure, lifestyle factors, and biomarkers in blood, elevated adolescent BMI (the weight in kilograms divided by the square of the height in meters; mean range for the first through last deciles, 17.3 to 27.6) was a significant...

Endogenous Testosterone and Mortality in Men: A Systematic Review and Meta-Analysis

Abstract: Context Low testosterone levels have been associated with outcomes that reduce survival in men. Objective Our objective was to perform a systematic review and meta-analysis of published studies to evaluate the association between endogenous testosterone and mortality. Data sources Data sources included MEDLINE (1966 to December 2010), EMBASE (1988 to December 2010), and reference lists. Study selection Eligible studies were published English-language observational studies of men that reported the association between endogenous testosterone and all-cause or cardiovascular disease (CVD) mortality. A two-stage process was used for study selection. 1) Working independently and in duplicate, reviewers screened a subset (10%) of abstracts. Results indicated 96% agreement, and thereafter, abstract screening was conducted in singlicate. 2) All full-text publications were reviewed independently and in duplicate for eligibility. Data extraction Reviewers working independently and in duplicate determined methodological quality of studies and extracted descriptive, quality, and outcome data. Data synthesis Of 820 studies identified, 21 were included in the systematic review, and 12 were eligible for meta-analysis [n = 11 studies of all-cause mortality (16,184 subjects); n = 7 studies of CVD mortality (11,831 subjects)]. Subject mean age and testosterone level were 61 yr and 487 ng/dl, respectively, and mean follow-up time was 9.7 yr. Between-study heterogeneity was observed among studies of all-cause (P Conclusion Low endogenous testosterone levels are associated with increased risk of all-cause and CVD death in community-based studies of men, but considerable between-study heterogeneity, which was related to study and subject characteristics, suggests that effects are driven by differences between cohorts (e.g. in underlying health status).

Relative Muscle Mass Is Inversely Associated with Insulin Resistance and Prediabetes. Findings from The Third National Health and Nutrition Examination Survey

Abstract: Context: Insulin resistance, the basis of type 2 diabetes, is rapidly increasing in prevalence; very low muscle mass is a risk factor for insulin resistance. Objective: The aim was to determine whether increases in muscle mass at average and above average levels are associated with improved glucose regulation. Design: We conducted a cross-sectional analysis of National Health and Nutrition Examination Survey III data. Participants: Data from 13,644 subjects in a national study were evaluated. Outcome Measurements: We measured homeostasis model assessment of insulin resistance (HOMA-IR), blood glycosylated hemoglobin level, prevalence of transitional/pre- or overt diabetes (PDM), and prevalence of overt diabetes mellitus. Results: All four outcomes decreased from the lowest quartile to the highest quartile of skeletal muscle index (SMI), the ratio of total skeletal muscle mass (estimated by bioelectrical impedance) to total body weight. After adjusting for age, ethnicity, sex, and generalized and central o...

Lifestyle changes in women with polycystic ovary syndrome

Abstract: Background Polycystic ovary syndrome (PCOS) affects 4% to 18% of reproductive-aged women and is associated with reproductive, metabolic and psychological dysfunction Obesity worsens the presentation of PCOS and weight management (weight loss, maintenance or prevention of excess weight gain) is proposed as an initial treatment strategy, best achieved through lifestyle changes incorporating diet, exercise and behavioural interventions Objectives To assess the effectiveness of lifestyle treatment in improving reproductive, anthropometric (weight and body composition), metabolic and quality of life factors in PCOS Search methods Electronic databases (Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, PsycINFO, CINAHL, AMED) (date of last search 7/9/2010), controlled trials register, conference abstracts, relevant journals, reference lists of relevant papers and reviews and grey literature databases, with no language restrictions applied Selection criteria Randomised controlled trials comparing lifestyle treatment (diet, exercise, behavioural or combined treatments) to minimal or no treatment in women with PCOS Data collection and analysis Two authors independently selected trials, assessed methodological quality and risk of bias and extracted data Main results Six studies were included with n=164 participants Three studies compared physical activity to minimal dietary and behavioural advice or no advice Three studies compared combined dietary, exercise and behavioural interventions to minimal intervention Risk of bias varied with 4/6 having adequate sequence generation and clinician or outcome assessor blinding and 3/6 having adequate allocation concealment, complete outcome data and being free of selective reporting There were no studies assessing the fertility primary outcomes of pregnancy, live birth and miscarriage and no data for meta-analysis on ovulation or menstrual regularity Lifestyle intervention provided benefits when compared to minimal treatment for secondary reproductive, anthropometric and reproductive outcomes These included endpoint values for total testosterone (mean difference (MD) -027 nmol/L, 95% confidence interval (CI) -046 to -009, P = 0004), hirsutism or excess hair growth by the Ferriman-Gallwey score (MD -119, 95% CI -235 to -003, P = 004), weight (MD -347 kg, 95% CI -494 to -200, P < 000001), waist circumference (MD -195 cm, 95% CI -334 to -057, P = 0006) and fasting insulin (MD -202 µU/mL, 95% CI -328 to -077, P = 0002) There was no evidence of effect of lifestyle for body mass index, free androgen index, sex hormone binding globulin, glucose or cholesterol levels; and no data for quality of life, patient satisfaction or acne Authors' conclusions Lifestyle intervention improves body composition, hyperandrogenism (high male hormones and clinical effects) and insulin resistance in women with PCOS There was no evidence of effect for lifestyle intervention on improving glucose tolerance or lipid profiles and no literature assessing clinical reproductive outcomes, quality of life and treatment satisfaction

Motivational interviewing to improve weight loss in overweight and/or obese patients: a systematic review and meta‐analysis of randomized controlled trials

Abstract: Motivational interviewing, a directive, patient-centred counselling approach focused on exploring and resolving ambivalence, has emerged as an effective therapeutic approach within the addictions field. However, the effectiveness of motivational interviewing in weight-loss interventions is unclear. Electronic databases were systematically searched for randomized controlled trials evaluating behaviour change interventions using motivational interviewing in overweight or obese adults. Standardized mean difference (SMD) for change in body mass, reported as either body mass index (BMI; kg m(-2) ) or body weight (kg), was the primary outcome, with weighted mean difference (WMD) for change in body weight and BMI as secondary outcomes. The search strategy yielded 3540 citations and of the 101 potentially relevant studies, 12 met the inclusion criteria and 11 were included for meta-analysis. Motivational interviewing was associated with a greater reduction in body mass compared to controls (SMD = -0.51 [95% CI -1.04, 0.01]). There was a significant reduction in body weight (kg) for those in the intervention group compared with those in the control group (WMD = -1.47 kg [95% CI -2.05, -0.88]). For the BMI outcome, the WMD was -0.25 kg m(-2) (95% CI -0.50, 0.01). Motivational interviewing appears to enhance weight loss in overweight and obese patients.

Effect of Obesity on Prognosis After Early-Stage Breast Cancer

Abstract: Purpose This study was performed to characterize the impact of obesity on the risk of breast cancer recurrence and death as a result of breast cancer or other causes in relation to adjuvant treatment. Patients and Methods Information on body mass index (BMI) at diagnosis was available for 18,967 (35%) of 53,816 women treated for early-stage breast cancer in Denmark between 1977 and 2006 with complete follow-up for first events (locoregional recurrences and distant metastases) up to 10 years and for death up to 30 years. Information was available on prognostic factors and adjuvant treatment for all patients. Univariate analyses were used to compare the associations of known prognostic factors and risks of recurrence or death according to BMI categories. Cox proportional hazards regression models were used to assess the influence of BMI after adjusting for other factors. Results Patients with a BMI of 30 kg/m2 or more were older and had more advanced disease at diagnosis compared with patients with a BMI be...

Outdoor temperature, age, sex, body mass index, and diabetic status determine the prevalence, mass, and glucose-uptake activity of 18F-FDG-detected BAT in humans.

Abstract: Context: In humans, the prevalence, mass, and glucose-uptake activity of 18F-fluorodeoxyglucose (18F-FDG)-detected brown adipose tissue (BAT), which are expectedly enhanced by a cold stimulus, also appear modulated by other factors that still have to be disentangled. Objective: The objective of the study was to investigate the factors determining the prevalence, mass, and glucose-uptake activity of 18F-FDG-detected BAT in humans. Research Design and Methods: We retrospectively analyzed all 18F-FDG positron emission tomography/computed tomography examinations performed between January 2007 and December 2008 at our institution for 18F-FDG uptake within the cervical/supraclavicular, mediastinal, paravertebral, and perirenal fat areas. The influence of outdoor temperature, sex, age, body mass index (BMI), plasma glucose level, diabetes diagnosis, day length, and cancer status on the prevalence, mass, and glucose-uptake activity of 18F-FDG-detected BAT depots was investigated. Results: Three hundred twenty-eig...

Long-term effects of changes in cardiorespiratory fitness and body mass index on all-cause and cardiovascular disease mortality in men: the Aerobics Center Longitudinal Study.

Abstract: Background—The combined associations of changes in cardiorespiratory fitness and body mass index (BMI) with mortality remain controversial and uncertain. Methods and Results—We examined the independent and combined associations of changes in fitness and BMI with all-cause and cardiovascular disease (CVD) mortality in 14 345 men (mean age 44 years) with at least 2 medical examinations. Fitness, in metabolic equivalents (METs), was estimated from a maximal treadmill test. BMI was calculated using measured weight and height. Changes in fitness and BMI between the baseline and last examinations over 6.3 years were classified into loss, stable, or gain groups. During 11.4 years of follow-up after the last examination, 914 all-cause and 300 CVD deaths occurred. The hazard ratios (95% confidence intervals) of all-cause and CVD mortality were 0.70 (0.59–0.83) and 0.73 (0.54–0.98) for stable fitness, and 0.61 (0.51–0.73) and 0.58 (0.42–0.80) for fitness gain, respectively, compared with fitness loss in multivariab...

Physical activity attenuates the influence of FTO variants on obesity risk: A meta-analysis of 218,166 adults and 19,268 children

Abstract: Background: The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n=218,166) and nine studies of children and adolescents (n=19,268). Methods and Findings: All studies identified to have data on the FTO rs9939609 variant (or any proxy [r(2)>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTOxPA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A-) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20-1.26), but PA attenuated this effect (p(interaction) = 0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio = 1.22/allele, 95% CI 1.19-1.25) than in the inactive group (odds ratio = 1.30/allele, 95% CI 1.24-1.36). No such interaction was found in children and adolescents. Conclusions: The association of the FTO risk allele with the odds of obesity is attenuated by 27% in physically active adults, highlighting the importance of PA in particular in those genetically predisposed to obesity.

Midlife overweight and obesity increase late-life dementia risk A population-based twin study

Abstract: Objective: The relation of overweight to dementia is controversial. We aimed to examine the association of midlife overweight and obesity with dementia, Alzheimer disease (AD), and vascular dementia (VaD) in late life, and to verify the hypothesis that genetic and early-life environmental factors contribute to the observed association. Methods: From the Swedish Twin Registry, 8,534 twin individuals aged ≥65 (mean age 74.4) were assessed to detect dementia cases ( DSM-IV criteria). Height and weight at midlife (mean age 43.4) were available in the Registry. Data were analyzed as follows: 1) unmatched case-control analysis for all twins using generalized estimating equation (GEE) models and 2) cotwin matched case-control approach for dementia-discordant twin pairs by conditional logistic regression taking into account lifespan vascular disorders and diabetes. Results: Among all participants, dementia was diagnosed in 350 subjects, and 114 persons had questionable dementia. Overweight (body mass index [BMI] >25–30) and obesity (BMI >30) at midlife were present in 2,541 (29.8%) individuals. In fully adjusted GEE models, compared with normal BMI (20–25), overweight and obesity at midlife were related to dementia with odds ratios (ORs) (95% CIs) of 1.71 (1.30–2.25) and 3.88 (2.12–7.11), respectively. Conditional logistic regression analysis in 137 dementia-discordant twin pairs led to an attenuated midlife BMI-dementia association. The difference in ORs from the GEE and the matched case-control analysis was statistically significant ( p = 0.019). Conclusions: Both overweight and obesity at midlife independently increase the risk of dementia, AD, and VaD. Genetic and early-life environmental factors may contribute to the midlife high adiposity–dementia association.

Mirror extreme BMI phenotypes associated with gene dosage at the chromosome 16p11.2 locus

Abstract: Both obesity and being underweight have been associated with increased mortality. Underweight, defined as a body mass index (BMI) ≤ 18.5 kg per m(2) in adults and ≤ -2 standard deviations from the mean in children, is the main sign of a series of heterogeneous clinical conditions including failure to thrive, feeding and eating disorder and/or anorexia nervosa. In contrast to obesity, few genetic variants underlying these clinical conditions have been reported. We previously showed that hemizygosity of a ∼600-kilobase (kb) region on the short arm of chromosome 16 causes a highly penetrant form of obesity that is often associated with hyperphagia and intellectual disabilities. Here we show that the corresponding reciprocal duplication is associated with being underweight. We identified 138 duplication carriers (including 132 novel cases and 108 unrelated carriers) from individuals clinically referred for developmental or intellectual disabilities (DD/ID) or psychiatric disorders, or recruited from population-based cohorts. These carriers show significantly reduced postnatal weight and BMI. Half of the boys younger than five years are underweight with a probable diagnosis of failure to thrive, whereas adult duplication carriers have an 8.3-fold increased risk of being clinically underweight. We observe a trend towards increased severity in males, as well as a depletion of male carriers among non-medically ascertained cases. These features are associated with an unusually high frequency of selective and restrictive eating behaviours and a significant reduction in head circumference. Each of the observed phenotypes is the converse of one reported in carriers of deletions at this locus. The phenotypes correlate with changes in transcript levels for genes mapping within the duplication but not in flanking regions. The reciprocal impact of these 16p11.2 copy-number variants indicates that severe obesity and being underweight could have mirror aetiologies, possibly through contrasting effects on energy balance.

Body mass index, prostate cancer-specific mortality, and biochemical recurrence: a systematic review and meta-analysis.

Abstract: Increasing evidence suggested obesity, measured by body mass index (BMI), was associated with prostate cancer-specific mortality, and its impact on biochemical recurrence was also inconclusive. We systematically searched MEDLINE, EMBASE, and bibliographies of retrieved studies up to January 5, 2010. We used random-effects meta-analysis to assess the relative risks (RR) of prostate cancer-specific mortality and biochemical recurrence associated with a 5 kg/m(2) increase in BMI. Among the six population-based cohort studies in 1,263,483 initially cancer-free men, 6,817 prostate cancer deaths occurred; a 5 kg/m(2) increase in BMI was associated with 15% (RR: 1.15, 95% confidence interval (CI): 1.06-1.25, P < 0.01) higher risk of dying of prostate cancer. In the six postdiagnosis survival studies on 18,203 patients with 932 prostate cancer deaths, a 5 kg/m(2) increase in BMI was associated with 20% higher prostate cancer-specific mortality (RR: 1.20, 95% CI: 0.99-1.46, P = 0.06). In the sixteen studies which followed 26,479 prostate cancer patients after primary treatment, a 5 kg/m(2) increase in BMI was significantly associated with 21% increased risk of biochemical recurrence (RR: 1.21, 95% CI: 1.11-1.31 P < 0.01). Elevated BMI is associated with risk of prostate cancer-specific mortality in prospective cohort studies and biochemical recurrence in prostate cancer patients. Its association with prostate cancer-specific mortality in diagnosed patients needs to be further evaluated.

Gastric Bypass vs Sleeve Gastrectomy for Type 2 Diabetes Mellitus: A Randomized Controlled Trial

Abstract: Objectives To determine the efficacies of 2 weight-reducing operations on diabetic control and the role of duodenum exclusion. Design Double-blind randomized controlled trial. Setting Department of Surgery of the Min-Sheng General Hospital, National Taiwan University. Patients We studied 60 moderately obese patients (body mass index >25 and 30 to 7.5%) after conventional treatment (>6 months) from September 1, 2007, through June 30, 2008. Patients and observers were masked during the follow-up, which ended in 2009, 1 year after final enrollment. Interventions Gastric bypass with duodenum exclusion (n = 30) vs sleeve gastrectomy without duodenum exclusion (n = 30). Main Outcome Measures The primary outcome was remission of T2DM (fasting glucose Results Of the 60 patients enrolled, all completed the 12-month follow-up. Remission of T2DM was achieved by 28 (93%) in the gastric bypass group and 14 (47%) in the sleeve gastrectomy group (P = .02). Participants assigned to gastric bypass had lost more weight, achieved a lower waist circumference, and had lower glucose, HbA1c, and blood lipid levels than the sleeve gastrectomy group. No serious complications occurred in either group. Conclusions Participants randomized to gastric bypass were more likely to achieve remission of T2DM. Duodenum exclusion plays a role in T2DM treatment and should be assessed. Trial Registration clinicaltrials.gov Identifier:http://clinicaltrials.gov/show/NCT00540462>NCT00540462(http://www.clinicaltrials.gov).

General parenting, childhood overweight and obesity-inducing behaviors: a review

Abstract: Despite emerging efforts to investigate the influence parents have on their children's weight status and related dietary and activity behaviors, reviews regarding the role of general parenting are ...

Body Adiposity and Type 2 Diabetes: Increased Risk With a High Body Fat Percentage Even Having a Normal BMI

Abstract: Obesity is the major risk factor for the development of prediabetes and type 2 diabetes. BMI is widely used as a surrogate measure of obesity, but underestimates the prevalence of obesity, defined as an excess of body fat. We assessed the presence of impaired glucose tolerance or impaired fasting glucose (both considered together as prediabetes) or type 2 diabetes in relation to the criteria used for the diagnosis of obesity using BMI as compared to body fat percentage (BF%). We performed a cross-sectional study including 4,828 (587 lean, 1,320 overweight, and 2,921 obese classified according to BMI) white subjects (66% females), aged 18-80 years. BMI, BF% determined by air-displacement plethysmography (ADP) and conventional blood markers of glucose metabolism and lipid profile were measured. We found a higher than expected number of subjects with prediabetes or type 2 diabetes in the obese category according to BF% when the sample was globally analyzed (P < 0.0001) and in the lean BMI-classified subjects (P < 0.0001), but not in the overweight or obese-classified individuals. Importantly, BF% was significantly higher in lean (by BMI) women with prediabetes or type 2 diabetes as compared to those with normoglycemia (NG) (35.5 ± 7.0 vs. 30.3 ± 7.7%, P < 0.0001), whereas no differences were observed for BMI. Similarly, increased BF% was found in lean BMI-classified men with prediabetes or type 2 diabetes (25.2 ± 9.0 vs. 19.9 ± 8.0%, P = 0.008), exhibiting no differences in BMI or waist circumference. In conclusion, assessing BF% may help to diagnose disturbed glucose tolerance beyond information provided by BMI and waist circumference in particular in male subjects with BMI <25 kg/m(2) and over the age of 40.