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Showing papers by "Claude Bouchard published in 1998"



Journal ArticleDOI
TL;DR: The hypothesis of maternal inheritance, with the father's contribution being environmental, was found to fit the data with estimates of maternal heritability, potentially associated with mitochondrial inheritance, reaching about 30%.
Abstract: This study investigates the familial resemblance of maximal oxygen uptake (VO2max) based on data from 86 nuclear families of Caucasian descent participating in the HERITAGE Family Study. In the current study, VO2max was measured twice on a cycle ergometer in 429 sedentary individuals (170 parents and 259 of their offspring), aged between 16 and 65 yr. The VO2max was adjusted by regression procedures for the effects of 1) age and sex; 2) age, sex, and body mass; and 3) age, sex, body mass, fat mass, and fat-free mass, as determined by underwater weighing. Evidence for significant familial resemblance was observed for each of the three VO2max phenotypes. Spouse, sibling, and parent-offspring correlations were significant, suggesting that both genetic and environmental factors contribute to the familial resemblance for VO2max. Maximal heritability estimates were at least 50%, a value inflated to an undetermined degree by nongenetic factors. The hypothesis of maternal inheritance, with the father's contribution being environmental, was also found to fit the data with estimates of maternal heritability, potentially associated in part with mitochondrial inheritance, reaching about 30%. These results suggest that genetic and nongenetic factors as well as maternal influences contribute to the familial aggregation of VO2max in sedentary individuals.

460 citations


Journal ArticleDOI
01 Jun 1998-Diabetes
TL;DR: The results of the present study suggest that visceral obesity is associated with an impaired postprandial TG clearance and the exaggerated postPRandial FFA response observed in subjects with high visceral AT suggests that visceral Obesity may contribute to fasting and postpr andial hypertriglyceridemia by altering FFA metabolism in the postpranderial state.
Abstract: Although metabolic disturbances are often observed in obese patients, increased accumulation of visceral adipose tissue (AT) has been shown to be more closely associated with high fasting triglyceride (TG) and insulin levels as well as with low HDL cholesterol concentrations than with excess body fatness per se Interestingly, the fasting concentration of plasma TGs has been shown to be an important determinant of the magnitude and duration of the postprandial TG response Yet little is known about the respective contributions of obesity versus excess visceral AT to the variation in postprandial TG clearance In the present study, we examined potential differences in postprandial triglyceride-rich lipoprotein (TRL) responses in subjects characterized by high versus low levels of visceral AT In a sample of 43 men (mean age: 413 +/- 96 years), we found that both excess body fat and visceral obesity were associated with increased postprandial TG responses in total TRL (r = 033-045) We also found a strong relationship between fasting plasma TG levels and postprandial total TRL-TG concentrations (r = 079, P or =130 cm2; n = 10) as assessed by computed tomography were characterized by increased medium- and small-TRL-TG responses (P < 005) compared with subjects with low visceral AT accumulation (<130 cm2; n = 10) Moreover, this elevated response of small-TRL triglycerides noted in men with high levels of visceral AT was not accompanied by a concomitant increased retinyl palmitate response in this TRL fraction, suggesting that visceral obesity in men is accompanied by higher postprandial VLDL production than is found in obese men with lower levels of visceral AT Increased postprandial insulin and free fatty acid (FFA) responses were also noted in men with high levels of visceral AT Finally, postheparin plasma lipoprotein lipase activity was negatively correlated with the total-TRL-TG response in a subsample of 32 individuals (r = -037, P < 005) The results of the present study suggest that visceral obesity is associated with an impaired postprandial TG clearance Furthermore, the exaggerated postprandial FFA response observed in subjects with high visceral AT suggests that visceral obesity may contribute to fasting and postprandial hypertriglyceridemia by altering FFA metabolism in the postprandial state

289 citations


Journal ArticleDOI
TL;DR: To achieve long-standing control of overweight, one should combine changes in eating and activity patterns, using behavior modification techniques, and the onus is also on society to reduce incentives for a sedentary lifestyle and over-consumption of food.
Abstract: Almost one-quarter of U.S. children are now obese, a dramatic increase of over 20% in the past decade. It is intriguing that the increase in prevalence has been occurring while overall fat consumption has been declining. Body mass and composition are influenced by genetic factors, but the actual heritability of juvenile obesity is not known. A low physical activity (PA) is characteristic of obese children and adolescents, and it may be one cause of juvenile obesity. There is little evidence, however, that overall energy expenditure is low among the obese. There is a strong association between the prevalence of obesity and the extent of TV viewing. Enhanced PA can reduce body fat and blood pressure and improve lipoprotein profile in obese individuals. Its effect on body composition, however, is slower than with low-calorie diets. The three main dietary approaches are: protein sparing modified fast, balanced hypocaloric diets, and comprehensive behavioral lifestyle programs. To achieve long-standing control of overweight, one should combine changes in eating and activity patterns, using behavior modification techniques. However, the onus is also on society to reduce incentives for a sedentary lifestyle and over-consumption of food. To address the key issues related to childhood weight management, the American College of Sports Medicine convened a Scientific Roundtable in Indianapolis.

242 citations


Journal ArticleDOI
TL;DR: There is a significant relationship between activity and health-related physical fitness, but a large part of the variability in fitness is not accounted for by physical activity as measured in this study.
Abstract: Purpose:To evaluate the relationship between indicators of physical activity and health-related fitness in youth 9-18 yrMethods:A cross-sectional sample of 356 boys and 284 girls 9-18 yr of age from phase I of the Quebec Family Study was studied The sample was divided into three age groups

123 citations


Journal ArticleDOI
TL;DR: An update of the human obesity gene map incorporating published results up to October 1997 is presented and studies reporting negative association and linkage results are listed, with the exception of the unlinked markers from genome-wide scans.
Abstract: An update of the human obesity gene map incorporating published results up to October 1997 is presented. Evidence from Mendelian disorders exhibiting obesity as a clinical feature; single-gene mutation rodent models; quantitative trait loci uncovered in human genome-wide scans and in crossbreeding experiments with mouse, rat, and pig models; association and case-control studies with candidate genes; and linkage studies with genes and other markers is reviewed. All chromosomal locations of the animal loci are converted into human genome locations based on syntenic relationships between the genomes. A complete listing of all of these loci reveals that all but chromosome Y of the 24 human chromosomes are represented. Some chromosomes show at least three putative loci related to obesity on both arms (1, 2, 6, 8, 11, and 20) and several on one chromosome arm only (3p, 4q, 5q, 7q, 12q, 13q, 15q, 15p, 22q, and Xq). Studies reporting negative association and linkage results are also listed, with the exception of the unlinked markers from genome-wide scans.

104 citations


Journal ArticleDOI
TL;DR: The results confirm the notion that high fat diets might lead over time to excess body fat deposition and confirm that SFA and MUFA intake also seem to be predictors of actual adiposity markers while high PUFA intake seems to exert no effect on these markers.
Abstract: Objectives: This study was undertaken to investigate the relation between dietary fat composition and adiposity in adult men. Subjects: A sample of 128 male subjects who participated in Phase 2 of the Quebec Family Study. Design: The association between adiposity and total dietary fat intake (TFI), saturated fat intake (SFA), monounsaturated fat intake (MUFA) and polyunsaturated fat intake (PUFA) was analyzed in the overall sample. A comparison of body fatness was also performed between consumers of high (4th quartile) and low amounts (1st quartile) of TFI, SFA, MUFA and PUFA. Results: Significant positive correlations were found between the percentage of dietary energy as total fat and body fatness. Men in the upper quartile of TFI displayed significantly more adiposity than those in the lower quartile. Significant differences were also observed when quartiles were established using SFA and MUFA. However, higher intakes of PUFA had no statistical effects on adiposity. Conclusion: These results confirm the notion that high fat diets might lead over time to excess body fat deposition. SFA and MUFA intake also seem to be predictors of actual adiposity markers while high PUFA intake seems to exert no effect on these markers. Sponsorship: This work forms part of a research program supported by the Medical Research Council of Canada (PG-11811).

102 citations


Journal ArticleDOI
TL;DR: The results indicate that time watching television has only a weak association with indicators of physical activity and health-related fitness in Québec youth.

94 citations


Journal ArticleDOI
TL;DR: Genes involved in the regulation of lipid storage and mobilization in the abdominal fat depot are potential candidates for these genetic pleiotropic effects.
Abstract: Abdominal visceral fat (AVF) is an obesity-related phenotype thought to be associated with insulin resistance, diabetes mellitus, and atherosclerosis. Significant genetic influences on both AVF and insulin levels have been reported. However, information is lacking as to whether common genetic influences on AVF and insulin levels exist. AVF was assessed by computed tomography scan, and fasting insulin was measured by RIA in 512 members of 98 sedentary Caucasian families participating in the HERITAGE Family Study. Baseline data, collected before exercise training, were used in the present investigation. A bivariate familial correlation model was applied to evaluate whether there are familial influences that are common to insulin and AVF before and after adjustment for total fat mass (FM), and to assess the overall heritability of insulin and AVF. The maximal heritability for AVF, before and after adjustment for total FM, was 42% and 50%, respectively; and for insulin, it was 21%. Interestingly, 29% of the f...

73 citations


Journal ArticleDOI
TL;DR: 20 wk of endurance exercise training had no effect on the RMR even in the presence of small changes in body composition and a large increase in VO2max.

71 citations


Journal ArticleDOI
TL;DR: It is concluded that within-subject day-to-day variation and measurement unreliabilities are generally small compared with the between-subject variance in the response to submaximal exercise at each of the clinical centers of the HERITAGE Family Study.
Abstract: This study determined the reproducibility of cardiovascular, respiratory, and metabolic responses to submaximal cycle ergometer exercise at two power outputs (50 W and 60% ˙VO2max) on each of two separate days in a sample of 390 subjects (198 men and 192 women) participating in the HERITAGE

Journal ArticleDOI
TL;DR: Analysis of adrenal and gonadal steroids and of conjugated metabolites before and after overfeeding in monozygotic twins supports the idea that there is a genotype effect on steroid circulating steroid levels and that these blood levels are correlated with the pattern of body fat distribution.
Abstract: An analysis of the data collected in the Quebec Overfeeding Study of identical twins was undertaken to determine any evidence of a genotype effect on plasma levels of adrenal and gonadal steroids arising from long term positive energy balance. Plasma levels of sex hormone-binding globulin (SHBG), testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone sulfate (DHEA-S), androsterone glucuronide, androstane-3 alpha, 17 beta-diol glucuronide (3 alpha-DIOL-G), and cortisol were measured in 12 pairs of young, sedentary, male monozygotic twins before and after 100 days of overfeeding. The dietary energy excess of 4.2 MJ/day (1000 Cal), 6 days a week, resulted in a total positive energy balance of 353 MJ (84,000 Cal). Overfeeding induced significant changes (P < 0.0001) in body weight and other measures of body composition. Within-twin pair resemblance was observed at baseline in all steroids, except cortisol [intraclass correlation range: DHEA-S, 0.50 (P < 0.05); DHT, 0.77 (P < 0.001)] and was lost with overfeeding, except for DHT and SHBG (P < 0.05). SHBG levels fell and 3 alpha-DIOL-G rose with the gain in body fatness. The change in testosterone was a significant correlate of the change in upper body fat (r = -0.48; P < 0.05). The change in 3 alpha-DIOL-G correlated positively with increases in all measures of central adiposity (r = 0.52; P < 0.01). A decrease in DHEA-S occurred with a higher, but not with a lower, gain in abdominal visceral fat (P < 0.05). Thus, analysis of adrenal and gonadal steroids and of conjugated metabolites before and after overfeeding in monozygous twins supports the idea that there is a genotype effect on steroid circulating steroid levels and that these blood levels are correlated with the pattern of body fat distribution. Moreover, the baseline within-twin pairs similarity in steroid levels was attenuated by prolonged positive energy balance and body fat gain.

Journal Article
TL;DR: The finding that the magnitude of the familial correlations was higher in the black sample than in the white sample suggest that the effects of host and familial environmental factors differ between the races.
Abstract: Resting blood pressure in both white and black families participating in the HERITAGE Family Study was analyzed using a simple familial correlation model to assess familial influences. The two samples of black and white families were analyzed separately and together, providing an opportunity to test for heterogeneity in the familial resemblance. Maximal heritability was 46% for systolic blood pressure (SBP) and 31% for diastolic blood pressure (DBP) in the pooled sample. Noticeably higher heritabilities were found in the black sample (68% for SBP and 56% for DBP) than in the white sample (43% for SBP and 24% for DBP). The patterns of familial correlations were similar in blacks and whites, with the exception that spouse resemblance was significant in white families but not in black families. These results along with the finding that the magnitude of the familial correlations was higher in the black sample than in the white sample suggest that the effects of host and familial environmental factors differ between the races.

Journal ArticleDOI
TL;DR: The UCP1 A-3826G sequence variation is not associated with obesity-related phenotypes and weight gain over time in subjects from the SOS cohorts, compared to what was found in other populations.
Abstract: OBJECTIVE: To investigate the relationships between the A–G point mutation at position −3826 bp in the 5′ flanking domain of the uncoupling protein 1 (UCP1 A-3826G) and some obesity phenotypes in the Swedish Obese Subjects (SOS) cohorts of obese and non-obese men and women. Previous studies have supported the hypothesis of an association between the UCP1 A-3826G polymorphism and body weight regulation in humans. DESIGN: Case-control study comparing obese subjects from the SOS registry and a sample of the Swedish general population (body mass index (BMI) 0.05). Similar results were obtained when the three genotypes were compared. CONCLUSIONS: In contrast to what was found in other populations, the UCP1 A-3826G sequence variation is not associated with obesity-related phenotypes and weight gain over time in subjects from the SOS cohorts.

Journal ArticleDOI
TL;DR: Results indicate no evidence for a difference in the frequency of two polymorphic restriction sites in the subunit 5 of the NADH dehydrogenase gene of mtDNA and one in the D-loop region between elite endurance athletes and sedentary controls.
Abstract: This study examined the associations between elite endurance athlete (EEA) status and three mitochondrial DNA (mtDNA) restriction fragment length polymorphisms (RFLPs) in the subunit 5 of the NADH dehydrogenase (MTND5) locus and one in the D-loop region. A group of 125 Caucasian male EEA well endowed with the phenotypic expression of VO2max (78.9 +/- 3.8 mL x kg(-1) x min(-1), mean +/- SD) and 65 sedentary controls (SCON: VO2max = 39.8 +/- 8.2 mL x kg(-1) x min(-1)) participated in the study. VO2max was determined during an incremental exercise test on a cycle ergometer or a motor-driven treadmill. mtDNA was extracted from white blood cells or lymphoblastoid cell lines and specific regions were amplified by the polymerase chain reaction. The Pearson Chi-square statistic test and Fisher exact test revealed no significant association (P > 0.05) between any of the three mtDNA RFLPs and EEA status. The MTND5-BamHI RFLP at bp 13,470 (morph 3) was found in 12.8% of the EEA and 12.3% of the SCON (chi2 = 0.009, P = 0.92). The prevalence of the MTND5-Ncil RFLP at bp 13,364 (morph 2) was 12.9% and 14% for the EEA and SCON, respectively (chi2 = 0.043, P = 0.83). The D-loop-KpnI RFLP at bp 16,133 (morph 1) was found in 5.8% of the EEA and in 1.6% of the SCON (Fisher exact test = 1.80, P = 0.18). The MTND5-HincII RFLP at bp 12,406 (morph 1) was not present in this study sample. These results indicate no evidence for a difference in the frequency of two polymorphic restriction sites in the subunit 5 of the NADH dehydrogenase gene of mtDNA and one in the D-loop region between elite endurance athletes and sedentary controls.

Journal ArticleDOI
TL;DR: High degree of genetic identity between the two traits is not surprising, since the BMI often is used as a surrogate for FM; however, simultaneous analysis of both phenotypes enabled the detection of a second major locus, which apparently does not affect extreme overweight but which affects variation in the "normal" range.
Abstract: The genetics of human fatness has been the subject of many recent studies, motivated by the increased morbidity and mortality associated with obesity, as well as the increasing prevalence of overweight and obesity. The body-mass index (BMI) and fat mass (FM), measured by underwater weighing, were assessed for 1,630 individuals from approximately 300 families from phase 1 of the Quebec Family Study. The two phenotypes are highly correlated ( approximately .8) in adults, and previous segregation analysis revealed evidence for a recessive major gene for each trait. In our study, we utilized bivariate segregation analysis to determine the source(s) of phenotypic correlation-namely, a pleiotropic major gene, shared familial factors/polygenes, or shared nontransmitted environmental factors. Analysis was performed by use of the Pedigree Analysis Package, with extensions to the bivariate case. Tests of hypotheses provided evidence for two pleiotropic recessive loci, together accounting for 64% and 47% of the variance in BMI and FM, respectively. Under the model, all sources of phenotypic correlation were significant: 73% of the covariance was attributed to the pleiotropic major loci, 8% to residual familial effects, and 19% to nontransmitted environmental factors. The high degree of genetic identity between the two traits is not surprising, since the BMI often is used as a surrogate for FM; however, simultaneous analysis of both phenotypes enabled the detection of a second major locus, which apparently does not affect extreme overweight (as does the primary major locus) but which affects variation in the "normal" range.

Journal ArticleDOI
TL;DR: The results suggest that in youth 9–18 years, a physique characterized by high endomorphy and mesomarphy is associated with higher levels of TG, LDL‐C, and GLY, and lower levels of HDL‐C.
Abstract: The relationship between physique and metabolic fitness was examined in a sample of 413 boys and 343 girls 9-18 years of age from Phase I of the Quebec Family Study. Physique was assessed using the Heath-Carter anthropometric somatotype. Indicators of metabolic fitness were plasma triglyceride levels (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and blood glucose levels (GLY). The sample was divided into three age groups, 9-12, 13-15, and 16-18 years of age. A partial canonical correlation analysis was used to quantify the relationship between the standardized somatotype and metabolic fitness variables (z-transformed) with age as the covariate. In both boys and girls the first canonical correlation is significant (P ⩽ 0.001) and indicates a relationship between the physique and metabolic fitness variables. By age group, the 16-18 year old boys, and the 9-12, 13-15, 16-18 year old girls demonstrate significant canonical correlations (P ⩽ 0.03). Overall, 8% to 19% of the variance in metabolic fitness can be explained by the Heath-Carter anthropometric somatotype. The makeup of the canonical variates is similar for all age groups. Generally, the physique domain is characterized by a positive loading for ectomorphy and negative loadings for endomorphy and mesomorphy. The metabolic fitness domain has a positive loading for HDL-C and negative loadings for TG, LDL-C, and GLY. The results suggest that in youth 9-18 years, a physique characterized by high endomorphy and mesomorphy is associated with higher levels of TG, LDL-C, and GLY, and lower levels of HDL-C. Am. J. Hum. Biol. 10:341-350, 1998. © 1998 Wiley-Liss, Inc.

Journal ArticleDOI
TL;DR: The contribution of obesity to serum lipid and lipoprotein levels and lipid metabolizing enzyme activities is assessed by examining 23 identical twin pairs who had, on the average, an 18-kg intrapair difference in BW.
Abstract: Obesity is associated with adverse changes in plasma lipoprotein metabolism, but it is not known completely how this association is modified by genetic factors. We assessed the contribution of obesity to serum lipid and lipoprotein levels and lipid metabolizing enzyme activities by examining 23 identical twin pairs (9 male, 14 female) who had, on the average, an 18-kg intrapair difference in BW. Compared with lean co-twins, obese co-twins had approximately 20% higher low-density lipoprotein (LDL) cholesterol (P < 0.01), 20% lower high-density lipoprotein2 cholesterol (P = 0.010), and 90% (men) or 35% (women) higher (P ≤ 0.06) total, very-low-density lipoprotein and LDL triglycerides. The pairs were divided into subgroups by the gender-specific median value of abdominal visceral fat (AVF) area in the obese co-twin and by apolipoprotein E 4 phenotype. The intrapair differences in serum cholesterol fractions were similar in twin pairs with high or low AVF, whereas only high AVF pairs showed significant diffe...

Journal ArticleDOI
TL;DR: Evidence from human association and linkage studies, performed with markers surrounding human homologs of the genes involved in mouse models of obesity, revealed that these genes tend to be linked more often to severe obesity than to moderate levels of obesity.
Abstract: It is well established that there is a significant familial aggregation of obesity, although most of the evidence regarding the genetic basis of obesity has been derived from overweight and moderately obese cases. Less is known about the contribution of genetic factors in severely obese individuals. This paper reviews the available evidence regarding the extent of familial aggregation of morbid obesity and the contribution of specific genes. The results of available studies suggest a stronger degree of familial resemblance for morbid obesity (body mass index (BMI > 40 kg/m 2 )) than for more moderate levels of obesity (BMI < 40 kg/m 2 ). Evidence from human association and linkage studies, performed with markers surrounding human homologs of the genes involved in mouse models of obesity, revealed that these genes tend to be linked more often to severe obesity than to moderate levels of obesity. Overweight, defined as a body mass index (BMI) of 27 kg/m 2 or more, and obesity, defined as a BMI of 30 kg/m 2 or more, are associated with an increased risk of several morbid conditions, such as hypertension, non-insulin-dependent diabetes mellitus (NIDDM), and cardiovascular diseases. The prevalence of over- weight and obesity is about 33% in the adult population in Canada (1) and the United States (2). Morbid obesity refers to more severe cases of obesity (i.e., those individuals located at the extreme of the distribution of BMI or body fat content). A BMI above 40, which represents an excess weight of at least 100 lbs for men and 80 lbs for women, is a common cutoff point used to categorize an individual as morbidly obese. Although it is well accepted that obesity aggregates in families, most of the evidence regarding the contribution of genetic factors in the etiology of obesity has been obtained from overweight or moderately obese individuals. Less is known about the extent of familial aggregation and the role of genetic factors in the more extreme forms of obesity. This paper reviews the role of genetic factors in morbid obesity from genetic epidemiology and molecular studies.

Journal ArticleDOI
TL;DR: Even though the adults displayed changes in fat balance generally following current public health recommendations, a substantial increase in skinfold thicknesses was observed in these subjects during follow-up, suggesting that there is a strong effect of age-related factors on fat balance.
Abstract: The aim of the present study was to evaluate changes in participation in physical activity and in fat and alcohol intake associated with ageing. This issue was examined in adults (n 207) who were tested between 1978 and 1982 and re-tested 12 years later. These adults were 42.3 (SD 4.9) years of age at baseline. Their children (n 122) were tested over the same follow-up period. They were, on average, 12.5 (SD 1.9) years at entry into the study. A decrease in the proportion of daily energy intake as fat and an increase in participation in vigorous physical activities were observed over the 12-year period in both groups. The proportion of dietary energy as alcohol remained stable in adults whereas it increased markedly in children. Correlation analyses between baseline and follow-up levels were significant for dietary fat and alcohol intake in adults. In children, the levels of these variables in the growing years did not predict the levels attained 12 years later. Even though the adults displayed changes in fat balance generally following current public health recommendations, a substantial increase in skinfold thicknesses was observed in these subjects during follow-up. This observation suggests that there is a strong effect of age-related factors on fat balance.

Journal ArticleDOI
TL;DR: HerITAGE-1 was slightly better than the equations of ACSM, Lang et al., and Latin and Berg using pretraining data but was not better when using post-training data.
Abstract: It was hypothesized that more accurate equations for estimating submaximal VO 2 during cycle ergometry could be developed if more independent variables were used in the equation. Purpose: The purposes of this study were: (1) to develop new equations for estimating submaximal VO 2 during cycle ergometry; and (2) to examine the accuracy of the newly developed equations and those of the American College of Sports Medicine (1995 ), Berry et al. (1993), Lang et al. (1992), Latin and Berg (1994), and Londeree et al. (1997). Methods: Subjects (715 men and women, ages 16-65 yr, from the HERITAGE Family Study) completed a maximal cycle ergometry test, two submaximal trials at 50 W and 60% of VO 2max , hydrostatic weighing, and stature and body mass measures before and after 20 wk of cycle ergometry training. Regression analysis generated prediction equations using pretraining data from the 60% trials. Results: No equation with more independent variables was better than an equation that used only power output. This equation, HERITAGE-1, with only power output was cross-validated using the jackknife technique. Paired t-tests, mean differences, SEEs, and Es were used to compare the VO 2 estimated by HERITAGE- I and those of previously published equations with the measured VO 2 at 60% of VO 2max . Conclusions: HERITAGE- was slightly better than the equations of ACSM, Lang et al., and Latin and Berg using pretraining data but was not better when using post-training data. All four of these equations were superior to the equations of Berry et al. and Londeree et al.

Journal ArticleDOI
TL;DR: Physique, as estimated with the Heath-Carter anthropometric somatotype, is not related to echocardiographic dimensions in children, youths and young adults.
Abstract: SummaryRelationships between echocardiographic dimensions and the Heath-Carter anthropometric somatotype were considered in healthy, non-obese children (8–11 year olds, n = 143), adolescents (12–15 year olds, n = 216) and young adults (16–24 years, n = 190). Cardiac dimensions, measured by M-mode echocardiography at end-diastole, included left ventricular internal diameter (LVIDd), posterior wall thickness (PWTd), and interventricular posterior wall thickness (STd). Left ventricular mass (LVM) and left ventricular end-diastolic volume (LVEDV) were estimated. Partial correlations between cardiac dimensions and each somatotype component were calculated, controlling for age and the other two components. Only 9 out of 45 correlations in males and 7 of 45 correlations in females were significant (p ˇ-0.05). LVM, LVEDV, and LVIDd were significantly related to somatotype in males, demonstrating significant positive correlations with mesomorphy (r = 0.25, 0.29 and 0.29, respectively) and ectomorphy (r = 0.22, 0.3...

Journal ArticleDOI
TL;DR: La carte genetique de l'obesite, etablie a partir des resultats provenant d'etudes animales and humaines, indique that tous les chromosomes, a l'exception du chromosome Y, contiennent des genes ou des locus potentiellement impliques dans l'etiologie de cette maladie.
Abstract: L'obesite est une maladie complexe qui affecte pres d'une personne sur trois dans la plupart des pays industrialises. Les recherches menees au cours des dix dernieres annees dans les domaines de l'epidemiologie genetique et de la genetique moleculaire permettent d'affirmer que l'obesite, ainsi que la susceptibilite des individus a prendre ou a perdre du poids, sont en partie determinees par nos genes. Dans le cadre de l'etude des familles de Quebec, l'heritabilite des divers phenotypes de l'obesite varie de 10% a 50 % et les analyses de segregation suggerent qu'un (ou quelques) gene(s) a transmission autosomique recessive pourrai(en)t y exercer une influence majeure. La carte genetique de l'obesite, etablie a partir des resultats provenant d'etudes animales et humaines, indique que tous les chromosomes, a l'exception du chromosome Y, contiennent des genes ou des locus potentiellement impliques dans l'etiologie de cette maladie.


Journal Article
TL;DR: In this article, a simple familial correlation model was used to assess familial influences in the HERITAGE family study and the results showed that the magnitude of the familial correlations was higher in the black sample than in the white sample.
Abstract: Resting blood pressure in both white and black families participating in the HERITAGE Family Study was analyzed using a simple familial correlation model to assess familial influences. The two samples of black and white families were analyzed separately and together, providing an opportunity to test for heterogeneity in the familial resemblance. Maximal heritability was 46% for systolic blood pressure (SBP) and 31% for diastolic blood pressure (DBP) in the pooled sample. Noticeably higher heritabilities were found in the black sample (68% for SBP and 56% for DBP) than in the white sample (43% for SBP and 24% for DBP). The patterns of familial correlations were similar in blacks and whites, with the exception that spouse resemblance was significant in white families but not in black families. These results along with the finding that the magnitude of the familial correlations was higher in the black sample than in the white sample suggest that the effects of host and familial environmental factors differ between the races.


01 Jan 1998
TL;DR: Both excess body fat and visceral obesity were found to be correlated with increased postprandial TG responses in totalTRL, and little is known about the respective contributions of obesity versus excess visceral AT to the variation in postpr andial TG clearance.
Abstract: Charles Couillard, Nathalie Bergeron, Denis Prud’homme, Jean Bergeron, Angelo Tr e m b l a y , Claude Bouchard, Pascale Mauriege, and Jean-Pierre DespresAlthough metabolic disturbances are often observed inobese patients, increased accumulation of visceral adi-pose tissue (AT) has been shown to be more closelyassociated with high fasting triglyceride (TG) andinsulin levels as well as with low HDL cholesterol con-centrations than with excess body fatness per se. Inter-e s t i n g l y , the fasting concentration of plasma TGs hasbeen shown to be an important determinant of the mag-nitude and duration of the postprandial TG response. Ye tlittle is known about the respective contributions ofobesity versus excess visceral AT to the variation inpostprandial TG clearance. In the present study, weexamined potential differences in postprandial triglyc-eride-rich lipoprotein (TRL) responses in subjects char-acterized by high versus low levels of visceral AT. In asample of 43 men (mean age: 41.3 ± 9.6 years), we foundthat both excess body fat and visceral obesity were asso-ciated with increased postprandial TG responses in totalTRL (