Showing papers by "Claude Bouchard published in 1992"
TL;DR: The results demonstrate that the amount of visceral AT and the ratio of abdominal to femoral AT measured by CT are important correlates of the alterations in carbohydrate and lipoprotein metabolism observed in obese men, and suggest that, in men, a high accumulation of femoral fat may be protective against the adverse effects of obesity, particularly abdominal obesity, on plasma lipop protein levels.
Abstract: The relations of regional adipose tissue (AT) distribution measured by computed tomography (CT) to plasma insulin-glucose homeostasis and lipoprotein-lipid levels were studied in 58 obese and 29 lean control men. In the group of obese men, the visceral AT area measured by CT was positively correlated with fasting plasma triglyceride and insulin levels and with glucose and insulin areas under the curves measured during a 75-g oral glucose tolerance test. Visceral AT area was also negatively associated with plasma high-density lipoprotein (HDL) and HDL2 cholesterol levels. The relative accumulation of abdominal fat, estimated by the ratio of abdominal to femoral AT areas obtained by CT, was also a significant correlate of indices of carbohydrate metabolism and was the best univariate correlate of plasma lipoprotein levels. No significant associations were observed between the visceral AT area, the ratio of abdominal to femoral AT areas, and indices of carbohydrate and lipoprotein metabolism in the group of lean men. On the other hand, the subcutaneous abdominal AT area was a significant correlate of the glucose area under the curve in both groups of men, but this association was not independent from the percentage of total body fat. No relationship was observed between the femoral AT area and indices of carbohydrate metabolism in either lean or obese groups. In obese men, however, the femoral AT area was negatively correlated with plasma triglyceride concentration and positively correlated with plasma HDL and HDL2 cholesterol levels.(ABSTRACT TRUNCATED AT 250 WORDS)
649 citations
Journal Article•
TL;DR: Comparison of measurements with self-reported prevalence estimates revealed a considerable amount of previously undiagnosed hypertension and diabetes in the obese subjects, suggesting that the excess health risks associated with obesity may not be fully appreciated.
Abstract: SOS (Swedish obese subjects) is an on-going intervention trial designed to determine whether the mortality and morbidity rates among obese individuals who lose weight by surgical means (gastric banding, vertical banded gastroplasty and gastric by-pass) differ from the rates associated with conventional treatment. For this purpose, the study is recruiting a sample of obese men and women who constitute a registry of potential subjects from which the participants are drawn. Eligibility criteria for participation in the registry were: age at application 37-57 years and BMI greater than or equal to 34 kg/m2 for men and greater than or equal to 38 kg/m2 for women. Before receiving a health examination, all patients complete extensive questionnaires on current and past health status, utilization of medical care and medications, socio-economic status, psychological profiles, dietary habits, physical activity, weight history, and familial disposition to obesity. Each surgical case is matched to its optimal control in the registry, to ensure that the two groups do not differ systematically with respect to any of 18 matching variables that may affect prognosis. The first 1006 subjects included in the registry have been studied with respect to morbidity and compared with on-going population studies of men and women in Goteborg, Sweden. The relative risks of prevalent disease and symptoms associated with obesity in 50-year-old males and females respectively were 4.3 and 4.7 (dyspnoea), 14.7 and 11.8 (angina), 6.3 (myocardial infarction, males only), 2.1 and 4.5 (hypertension), 5.2 and 6.6 (diabetes), 4.6 and 26.1 (claudication) and 1.7 and 1.8 (gall bladder disease). Correspondingly, obese males and females display elevations of systolic and diastolic blood pressure, fasting glucose, insulin, triglyceride, and uric acid levels. However, total cholesterol was not increased in obese males and was in fact significantly lower in obese compared with reference women. HDL-cholesterol was lower in obese than reference men (data were not available in reference women). The rate of taking sick pensions was over twice as high in SOS obese patients than in population controls. Finally, comparison of measurements with self-reported prevalence estimates revealed a considerable amount of previously undiagnosed hypertension and diabetes in the obese subjects. These data suggest that the excess health risks associated with obesity may not be fully appreciated.
287 citations
279 citations
241 citations
TL;DR: In this article, the associations of body mass index (BMI), absolute fat mass, percent body fat, and regional fat distribution with concentrations of fasting blood glucose and blood pressure were examined cross-sectionally in 1551 men and women aged 15-79 y from two study centers.
197 citations
TL;DR: The results suggest that aerobic exercise training, per se, irrespective of the changes in total body fat, seems to have beneficial effects on carbohydrate and lipid metabolism that may potentially reduce the risk of coronary artery disease (CAD) and a concomitant reduction in body fat mass probably amplifies the beneficial effects of aerobic exerciseTraining on metabolism.
Abstract: Thirty-one obese, premenopausal women aged 35.4 +/- 5.1 (SD) years exercised for 90 minutes at approximately 55% of maximal aerobic power (VO2max) four to five times a week for a period of 6 months. The training program induced a significant increase in VO2max (P < .001) and significant improvements in carbohydrate and lipid metabolism, as reflected by decreased plasma insulin (INS) concentrations measured in the fasting state and after glucose (GLU) ingestion (INS area, P < .001), by reduced plasma cholesterol (C) and low-density lipoprotein cholesterol (LDL-C) levels (P < .001), and by increased ratios of high-density lipoprotein cholesterol (HDL-C)/LDL-C and HDL2-C/HDL3-C (P < .05 and P < .001, respectively). Changes in body fat mass were positively associated with changes in the INS area/GLU area ratio (r = .49, P < .05) and with changes in very-low-density lipoprotein triglycerides ([VLDL-TG] r = .49, P < .05). Furthermore, changes in the INS area were positively associated with changes in VLDL-TG (r = .51, P < .05). Although no significant mean change in body composition was observed, important individual variation was noted. Twenty women showed a reduction in body fat mass (mean reduction, 2.63 +/- 2.2 kg), whereas 11 women showed an increase in adipose mass (mean increase, 2.79 +/- 2.36 kg). Comparable increases in VO2max were observed between the two groups. The group that showed a decrease in body fat mass with exercise also had significant improvements in carbohydrate and lipid metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)
116 citations
TL;DR: Abdominal obesity should be considered as a factor that exacerbates an individual's susceptibility to cardiovascular disease, and variations in several genes relevant to lipid and lipoprotein metabolism may alter the relation of abdominal obesity to dyslipoproteinemias.
Abstract: Obesity has a multifactorial origin. However, although environmental variables undoubtedly play a role in the development of obesity, it is now clear that genetic variation is also involved in the determination of an individual's susceptibility to body fat accumulation. In addition, it is also widely accepted that obesity is not a single homogeneous phenotype. It is also heterogeneous regarding its causes and metabolic complications. The regional distribution of body fat appears to be an important correlate of the metabolic complications that have been related to obesity. Due to their higher accumulation of abdominal fat, men are generally more at risk for the metabolic complications of obesity than women whereas some obese women, with large gluteal-femoral adipose depots may have a cosmetic problem which may not necessarily require medical intervention. Several studies have been conducted to understand the mechanisms by which abdominal obesity is related to diabetes, hypertension and cardiovascular disease. It appears that the increased risk of abdominal obesity is the result of complex hormonal and metabolic interactions. Studies in genetic epidemiology have shown that both total body fatness and the regional distribution of body fat have a significant genetic component. Standardized intervention studies using an identical twin design have shown that individuals that have the same genetic background tend to show similar changes in body fat and in plasma lipoprotein levels when exposed to standardized caloric excess or energy restriction. Finally, although abdominal obesity is a significant risk factor for cardiovascular disease, not every abdominal obese subject will experience metabolic complications, suggesting that some obese individuals may be more susceptible than others. Variation in several genes relevant to lipid and lipoprotein metabolism may alter the relation of abdominal obesity to dyslipoproteinemias. Abdominal obesity should therefore be considered as a factor that exacerbates an individual's susceptibility to cardiovascular disease.
64 citations
Journal Article•
TL;DR: The finding of commingling of distributions for almost all phenotypes is consistent with (but not evidence for) major gene effects, however, for some of the measures the effect of a putative major locus genotype may be mediated by covariates such as age and/or sex.
Abstract: Regional fat distribution is related to higher risk of diabetes and cardiovascular morbidity and mortality, independent of excess body mass for height. In particular, the male (android) pattern of fat deposition, which is characterized by greater truncal and abdominal fat stores relative to extremity fat levels, is associated with a higher propensity to metabolic complications. Motivated by these considerations, we have initiated a systematic investigation of several measures of regional fat distribution aimed at the detection of possible single gene effects. In this paper, we assess the evidence for commingling in the distributions of these variables in a large French-Canadian study. Two measures approximating the size of subcutaneous fat stores relative to total body fat were considered: the sum of six skinfolds (SF6 = abdominal + supra-iliac + subscapular + calf + tricep + bicep), and the sum of three trunk skinfolds (TSF3 = abdominal + supra-iliac + subscapular). In addition, two measures assessing the distributional pattern of subcutaneous fat were considered: the ratio of TSF3 to the sum of the three extremity skinfolds (TER), and a relative fat pattern index [RFPI = subscapular/(subscapular + supra-iliac)]. All four measures were assessed both prior to and after adjusting for total fat mass, which was measured using underwater weighing. Significant distributional heterogeneity was observed for some of these measures, either between generations and/or between the sexes. In general, however, fat mass adjustment tended to eliminate the heterogeneity; the exception was for RFPI, for which sex differences were noted both prior to and after the adjustment. The finding of commingling of distributions for almost all phenotypes is consistent with (but not evidence for) major gene effects. However, for some of the measures the effect of a putative major locus genotype may be mediated by covariates such as age and/or sex.
38 citations
TL;DR: The group that showed a decrease in body fat mass with exercise also had significant improvements in carbohydrate and lipid metabolism, as reflected by decreased plasma insulin concentrations measured in the fasting state and after glucose (GLU) ingestion.
Abstract: Thirty-one obese, premenopausal women aged 35.4 +/- 5.1 (SD) years exercised for 90 minutes at approximately 55% of maximal aerobic power (VO2max) four to five times a week for a period of 6 months. The training program induced a significant increase in VO2max (P < .001) and significant improvements in carbohydrate and lipid metabolism, as reflected by decreased plasma insulin (INS) concentrations measured in the fasting state and after glucose (GLU) ingestion (INS area, P < .001), by reduced plasma cholesterol (C) and low-density lipoprotein cholesterol (LDL-C) levels (P < .001), and by increased ratios of high-density lipoprotein cholesterol (HDL-C)/LDL-C and HDL2-C/HDL3-C (P < .05 and P < .001, respectively). Changes in body fat mass were positively associated with changes in the INS area/GLU area ratio (r = .49, P < .05) and with changes in very-low-density lipoprotein triglycerides ([VLDL-TG] r = .49, P < .05). Furthermore, changes in the INS area were positively associated with changes in VLDL-TG (r = .51, P < .05). Although no significant mean change in body composition was observed, important individual variation was noted. Twenty women showed a reduction in body fat mass (mean reduction, 2.63 +/- 2.2 kg), whereas 11 women showed an increase in adipose mass (mean increase, 2.79 +/- 2.36 kg). Comparable increases in VO2max were observed between the two groups. The group that showed a decrease in body fat mass with exercise also had significant improvements in carbohydrate and lipid metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)
28 citations
TL;DR: It is suggested that in men with alterations of glucose-insulin homeostasis, the relationship of body fat distribution to glucose tolerance and plasma insulin levels is different in those with no family history of diabetes than in subjects with a positive familyHistory of diabetes.
Abstract: The interaction between environmental and genetic factors in the alterations of glucose-insulin homeostasis was studied in 104 non-diabetic men. Family history of diabetes mellitus was used as an index of genetic predisposition to diabetes. Body composition was measured by under-water weighing whereas subcutaneous and visceral adipose tissue areas were measured at the abdominal and femoral levels by computed tomography. The sample was first divided into two groups. The first group included subjects with “normal” glycaemic and insulinaemic responses during a 75 g oral glucose tolerance test. The second group was composed of subjects either with a high glucose response or high insulin response or both. Men included in the second group were different from the “normal” subjects for almost all body fatness variables. They also presented a prevalence of a positive family history of diabetes which was significantly higher than “normal” subjects. The second group was then divided into three distinct subgroups based on insulin and glucose responses of the subjects during the oral glucose tolerance test. Subjects with high insulin but “normal” glucose responses were characterized by significantly higher levels of total body fat and deep abdominal adipose tissue when compared to the “normal” group (p<0.05). Men with both high insulinaemic and glycaemic responses displayed higher body fatness values and higher deep and subcutaneous abdominal adipose tissue areas (p<0.05) in comparison with “normal” subjects. They also had a higher body mass index at age 20 years than control subjects and subjects with high insulin but “normal” glucose responses. In contrast, subjects with “normal” insulin but with high glucose responses were not different from the “normal” group with regard to body fat and adipose tissue areas. These results show the heterogeneous origin of altered glucose-insulin homeostasis in non-diabetic men. Finally, subjects in the altered glucose-insulin homeostasis group with no family history of diabetes displayed a higher body mass index at age 20 years (p<0.05) in comparison with subjects who had a positive family history of the disease. They also presented a greater abdominal-to-thigh fat ratio measured by computed tomography. These results suggest that in men with alterations of glucose-insulin homeostasis, the relationship of body fat distribution to glucose tolerance and plasma insulin levels is different in those with no family history of diabetes than in subjects with a positive family history of diabetes.
16 citations
TL;DR: Results showed that the blood pressure response to epinephrine infusion was not correlated with the blood Pressure response to submaximal exercise, however, post-exercise and post-infusion systolic blood pressure responses were significantly associated (r = 0.81, p less than 0.01).
Abstract: This study was undertaken (1) to examine the relation of plasma catecholamine and insulin levels to the blood pressure response during and after submaximal exercise, (2) to verify whether the blood pressure response to an epinephrine infusion is associated with the blood pressure response to a prolonged submaximal exercise, and (3) to study some potential correlates of the hypotensive effect of prolonged aerobic exercise. Nine normotensive young men (mean age 22.0 ± 1.4 years) were subjected to a 1-h epinephrine infusion protocol and a 1-h submaximal exercise test on a cycle ergometer. The two tests were performed 1 week apart. The physiological and hormonal responses observed during the submaximal exercise test were generally greater than those observed during the epinephrine infusion test. Blood pressure responses in both tests showed no significant association with changes in plasma insulin levels. Changes in plasma norepinephrine concentration were positively correlated with changes in systolic blood ...
Book•
01 Jan 1992
TL;DR: In this paper, the authors introduce the physical activity sciences and present the search for knowledge, application of knowledge, service areas, and future trends in the Physical Activity Sciences, as well as the future.
Abstract: Part I: Introduction to the Physical Activity Sciences. Part II: The Search for Knowledge: Research Areas in the Physical Activity Sciences. Part III: The Application of Knowledge: Service Areas of the Physical Activity Sciences. Part IV: The Future: Emerging Trends in the Physical Activity Sciences.
TL;DR: The results suggest that the reduction in AT-LPL activity in both fat depots following endurance training in obese women can occur despite the lack of significant decrease in body weight and average fat cell size.
Abstract: Abdominal and femoral adipose tissue lipoprotein lipase (AT-LPL) activities were measured in ten obese premenopausal women (mean age 35 +/- 5 years) who took part in a six month endurance exercise training programme. The programme involved four to five 90 min training sessions per week at about 50 to 55% of maximal endurance power (VO2max). Before training, the ratio of insulin to glucose area measured during an oral glucose tolerance test (OGTT) was significantly correlated with fat mass (r = 0.72, P < 0.05) as well as with abdominal AT-LPL activity (r = 0.69, P < 0.05). The training programme induced a significant increase in VO2max (P < 0.05) whereas no significant change in the mean body composition was observed. Abdominal as well as femoral AT-LPL activities were significantly reduced after the exercise training programme (P < 0.05) whereas plasma post-heparin (PH) LPL activity was significantly increased by training (P < 0.05). No significant association was observed between changes in VO2max and in body composition parameters and changes in abdominal or femoral AT-LPL activities. However, changes in insulin sensitivity, as estimated by changes in the insulin area/glucose area ratio were positively correlated with changes in abdominal AT-LPL activity expressed on a per cell (r = 0.72, P < 0.05) or per surface area (r = 0.81, P < 0.01) basis. These results suggest that the reduction in AT-LPL activity in both fat depots following endurance training in obese women can occur despite the lack of significant decrease in body weight and average fat cell size.(ABSTRACT TRUNCATED AT 250 WORDS)