Claude Bouchard

..Individuals differ in the response to regular exercise. Whether there are people who experience adverse changes in cardiovascular and diabetes risk factors has never been addressed...

..Combining transcriptomic and genomic technologies has also yielded highly promising results concerning the ability to predict trainability among sedentary people...

..These genomic predictors of the response of Vo(2max) to regular exercise provide new targets for the study of the biology of fitness and its adaptation to regular exercise. Large-scale replication studies are warranted...

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..The present findings may be useful in the ongoing effort to search for genes contributing to inflammation and to identify individuals at an increased risk of chronic inflammatory diseases...

..Gene-gene interactions between the PTPN1 and leptin receptor genes contributed to the phenotypic variability of insulin sensitivity. The PTPN1 Pro387Leu variant was associated with lower glucose tolerance...

..The most promising regions for fine mapping in the HERITAGE Family Study were found on 2q33 for HR50 training response in whites, on 10q25-26 for baseline HR60 in blacks, and on 18q21-22 for both baseline HR50 and DeltaHR60 in whites...

..We conclude that considerable locus heterogeneity exists even within populations, which should be taken into account when considering candidate gene studies of energy metabolism phenotypes and other complex traits...

..Despite adiponectin's presumed role in fatty acid oxidation and energy homeostasis, little is known about the effect of gene variants on substrate oxidation, energy expenditure, and adiposity-related phenotypes...

..Pro-inflammatory cytokines, such as tumor necrosis factor alpha (TNF-alpha), stimulate the release of C-reactive protein (CRP). We investigated the association between the TNF-alpha G-308A polymorphism and plasma CRP levels...

..The benefits from an exercise program on Si are likely to be substantial in the general population given the high frequency of the LIPC -514C allele, particularly in whites...

..The present findings may be important in identifying individuals at increased risk of developing type 2 diabetes and who are most likely to benefit from a physically active lifestyle...

..There is increasing interest in understanding racial differences in adiposity in specific body depots as a way to explain differential health risks associated with obesity...

..Resistance to exercise-induced reduction in total adiposity may represent one mechanism by which the FTO A allele promotes overweight and obesity...

..Exogenous administration of AGRP in rodents predisposes to high fat and high sugar intakes...

..Similar interaction was observed in blacks (P = 0.046). Variations in the LEP and LEPR genes are associated with the magnitude of the effects of regular exercise on glucose homeostasis in nondiabetic individuals...

..Associations between preproghrelin DNA variants and obesity-related phenotypes were studied in 3004 subjects from the Québec Family Study (QFS), the HERITAGE Family Study (HERITAGE), and the Swedish Obese Subjects (SOS) Study...

..To describe the prevalence of time spent in sedentary behaviors (e.g., TV/video and computer use) among youth in the US...

..Men exhibit racial differences for tHcy responses to exercise training. Regular aerobic exercise has favorable effects on individuals with hyperhomocysteinemia, but tHcy slightly increased in individuals within the normal range...

..Adiponectin is an adipocytokine with lowered blood levels in obesity and Type 2 diabetes mellitus. We sought to define the specific effects of different alleles of the gene encoding adiponectin...

..Moreover, there are 15 mitochondrial genes in which sequence variants have been shown to influence relevant fitness and performance phenotypes...

..Visceral adipose tissue (VAT) has been identified as a harmful fat depot, and sex and race differences in VAT have been reported in white and African Americans...

..In conclusion, results from our large, biethnic sample of men and women found a FM-FFM relationship very close to that originally described by Forbes, absent of significant variability by ethnicity or sex...

..Further study may refine these quantitative trait loci to identify potential candidate genes for energy and specific macronutrient intakes that would be amenable to more detailed molecular studies...

..Lpin1 was identified as the mutated gene in the fatty liver dystrophy mouse, which exhibits lipin deficiency and features of human lipodystrophy...

..Sex differences, and in some instances race differences, in the relationships between anthropometry and fat-specific depots demonstrate that these characteristics need to be considered when predicting adiposity from WC or BMI...

..DISCUSSION: The present study indicates that the QTL on chromosome 1q43 specifically affects total adiposity and provides a genetic mapping framework for the dissection of this adiposity locus...

..09, P=.023) and 27-33% lower work index (F=6.23, P=.004) than the CC homozygotes and CT heterozygotes. The results suggest that DNA sequence variation in the DRD2 gene is associated with physical activity levels among White women...

..The CETP and APOE genotypes account for up to 9% of the variance in HDL-c phenotypes in the HERITAGE Family Study...

..There are no apparent ethnic differences in men; however, in AA women the optimal BMI and WC values are ~3 kg/m2 and 5 cm higher than in white women...

..In conclusion, our results do not support the prevailing notion that sequence variation in the melanocortin 4 receptor gene is a frequent cause of human obesity...

..3, 3q13.3, 12q13.2) and one for baseline SV50 and Q50 (10p14). All these chromosomal regions include several potential candidate genes and therefore warrant further studies in the HERITAGE cohort and other studies...

..3-kb(-) subjects with overfeeding, suggesting more unfavorable metabolic changes compared with the 3.3-kb(+) subjects...

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..To study the effect of exercise training on plasma C-reactive protein, a marker of inflammation...

..04). No significant associations were found in Black women. Low Ca(2+) intake may be associated with higher adiposity, particularly in men and White women...

..2, 9q31.1, 13q22-q31), and time spent in physical activity (11p15 and 15q13.3). CONCLUSION: This study identified several chromosomal regions harboring genes that may contribute to the propensity to be physically active or sedentary...

..To determine contributions of trunk and extremity adiposity to cardiometabolic risk factors (blood pressure, fasting blood glucose, HDL cholesterol, and triglycerides) among white and African American adults...

..Genetic factors contribute significantly to the interindividual differences in endurance training-induced changes in BP. However, similar data on the genotype-by-fitness interactions on the risk of hypertension are scarce...

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..CONCLUSION: These data provide evidence of familial aggregation for enzyme activities of the main energy metabolism pathways of the skeletal muscle in the sedentary state and in response to regular exercise...

..Since TTN is the largest gene in the human genome, the challenge is to identify the DNA sequence variants contributing to the interindividual differences in cardiac adaptation to endurance training...

..Some of these chromosomal regions harbor promising potential candidate genes...

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..Furthermore, training-induced changes in submaximal exercise stroke volume may be due to mitochondrial function and variation in KIF5B expression as determined by functional SNPs in its promoter...

..To investigate the prevalence of distinct combinations of components of the metabolic syndrome among adolescents...

..We examined the associations of gene variants with symptom-limited exercise test duration at baseline and decrease in duration over 20 years...

..Metabolic risk varies within adult body mass index (BMI) categories; however, the development of BMI-specific metabolic risk from childhood is unknown...

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..In conclusion, adiponectin DNA sequence variations might play a role in the complications of morbid obesity and should be further investigated...

..The objective of this analysis was to examine trends in occupational physical activity during the past 5 decades and explore how these trends relate to concurrent changes in body weight in the U.S...

..To examine 35-year trends in the prevalence of overweight and obesity among children and adolescents from Bogalusa, Louisiana...

..We conclude from this first installment that exercise scientists need to prioritize high-quality research designs and that replication studies with large sample sizes are urgently needed...

..A genome-wide linkage scan identified a quantitative trait locus for exercise training-induced changes in submaximal exercise (50 W) heart rate (DeltaHR50) on chromosome 2q33.3-q34 in the HERITAGE Family Study (n=472)...

..However, the influence of body mass index (BMI) or waist circumference (WC) on the relationship between IMT and metabolic risk is unclear...

..Identification of functional mutation(s) could thus help in the development of ROCK2-specific treatments...

..The obesity gene map shows putative loci on all chromosomes except Y. The electronic version of the map with links to useful publications and relevant sites can be found at http://obesitygene.pbrc.edu...

..These results suggest that DNA sequence variation in the MC4R locus may contribute to the gain in body height from childhood to adulthood...

..Our study provides an illustrative example of how physical activity and fitness level modifies the associations between a candidate gene and outcome phenotype...

..To investigate associations between anthropometric measurements and total body fat, abdominal adipose tissue, and cardiovascular disease risk factors in a large biracial sample...

..There is a wide individual heterogeneity in the maximal aerobic fitness (V x O 2max) response to exercise training...

..Differences in adiposity between ethnic groups should be considered in disease risk assessment and stratification as they are observed even for a given BMI level...

..Summarizing, the observed associations with resting and submaximal-exercise cardiovascular and metabolic traits in the HERITAGE Family Study are likely due to neither variation in the promoter nor known coding SNPs of SLC4A5...

..Overall, more than 430 genes, markers, and chromosomal regions have been associated or linked with human obesity phenotypes. The electronic version of the map with links to useful sites can be found at http://obesitygene.pbrc.edu...

..We examined the associations of eight candidate genes, identified by genome-wide association studies, with HDL-C at baseline and 10 yr after bariatric surgery in the Swedish Obese Subjects study...

..DNA sequence variation in the PPARdelta locus is a potential modifier of changes in cardiorespiratory fitness and plasma HDL-C in healthy individuals in response to regular exercise...

..Finally, 13 sequence variants in mitochondrial DNA have been shown to influence relevant fitness and performance phenotypes...

..Furthermore, within-pair resemblance among twin brothers strongly suggests that genetic differences partially account for the variation in the response of lipids and lipoproteins to the negative energy balance protocol...

..69, P<0.01). These results strongly suggest that the response of plasma lipoproteins to chronic energy surplus has a significant genetic component as does the detrimental effect of chronic caloric affluence on CHD risk...

..43 to 0.53, and account for 18% to 28% of the variance in the response to overfeeding. The results suggest that an elevated skeletal muscle oxidative capacity plays a protective role in the response to long-term positive energy balance...

..Likewise, the number of negative studies, which are only partially reviewed here, is also on the rise...

..Understanding the relative contribution of global genetic variation and of DNA sequence variants in specific genes is important in the effort to influence dietary habits in a healthier direction...

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..It is possible that the prevalence of childhood obesity is increasing across generations as a result of positive assortative mating with obese husbands and wives contributing more obese offspring than normal-weight parents...

..However, comparisons depend on the true prevalence within ethnicity-gender groups. After controlling for obesity prevalence, disparity in underestimation was greater in EA than in AA men (P < 0.003) but not women...

..It was the purpose of the workshop to define the conditions under which gene-behavior interaction effects of relevance to human obesity could be reliably identified...

..Progress is likely to come when studies will be designed to truly address gene-exercise or physical activity interaction issues and with sample sizes that will provide adequate statistical power...

..The GNB3 genotype may play a minor role in HR and body fatness regulation in blacks and in responsiveness of resting BP to endurance training in black women...

..Promising physical activity interventions among children were presented, and important research, policy and practice recommendations to address the issue of physical inactivity and obesity were provided...

..We prospectively examined sitting time and mortality in a representative sample of 17,013 Canadians 18-90 yr of age...

..The c.199G-->A polymorphism in hAGRP could, therefore, play a role in the development of human obesity in an age-dependent fashion...