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A Tremblay

Publications and source records attributed to A Tremblay.

371 records · Page 21Linked to original sources
PubMedDate not supplied

Genetic and environmental determinants of serum lipids and lipoproteins in French Canadian families.

The contribution of genetic and environmental factors in serum triglycerides (TG), total cholesterol (CHOL), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and HDL-C/CHOL ratio were studied in 1630 subjects from 375 families of French descent by using a path analysis procedure. Familial correlations were computed in several pairs of biological relatives and relatives by adoption after adjustment for age and gender effects and after further adjustment for physical fitness, level of habitual physical activity, total body fat and fat distribution, diet, smoking, and alcohol consumption. The model of path analysis allowed the separation of transmissible variance (t2) into genetic (h2) and cultural (b2) components of inheritance. Under the most parsimonious solution and after adjustment for age, gender, and concomitants, the transmissible variance was entirely accounted for by genetic factors (t2 = h2), with h2 estimates of 0.52, 0.55, 0.60, and 0.63 for TG, CHOL, LDL-C, HDL-C, and HDL-C/CHOL, respectively. These estimates were similar to those obtained after adjustment for age and gender effects only. The contribution of nontransmissible environmental factors ranged from 0.48 for TG to 0.37 for HDL-C/CHOL ratio. These results suggest that both genetic and environmental factors contribute to the variation in blood lipids and lipoproteins in this population and that nongenetic influences are not associated with cultural factors transmitted across generations.

Adolescent↗
PubMedDate not supplied

Role of hepatic-triglyceride lipase activity in the association between intra-abdominal fat and plasma HDL cholesterol in obese women.

Intra-abdominal fat content is an important variable in the association between regional body fat distribution and plasma high density lipoprotein (HDL) cholesterol levels. In the present study, we report on the role of plasma postheparin lipases as well as abdominal and femoral adipose tissue lipoprotein lipase activities in the association between body fat distribution and plasma lipoprotein levels. Postheparin plasma lipoprotein lipase (LPL), hepatic-triglyceride lipase (H-TGL), abdominal and femoral adipose tissue (AT)-LPL activities and plasma lipoprotein levels were measured after an overnight fast in a sample of 16 obese women (ages 36.0 +/- 6.1 years [mean +/- SD], percent body fat 46% +/- 6%). Computed axial tomography was used to assess body fat distribution. Plasma postheparin LPL activity was neither correlated with total adiposity nor with the level of intra-abdominal fat. Intra-abdominal fat deposition was, however, positively correlated with H-TGL activity (r = 0.66, p less than 0.005). Furthermore, covariance analysis showed that the association between intra-abdominal fat and H-TGL was independent from total adiposity. Plasma postheparin LPL and abdominal AT-LPL activities showed no significant correlation with plasma lipoprotein levels, whereas femoral AT-LPL activity was positively correlated with the HDL2 cholesterol/HDL3 cholesterol ratio (r = 0.51, p less than 0.05). H-TGL activity was, however, negatively correlated with HDL2 cholesterol (r = -0.60, p less than 0.05), but not with HDL3 cholesterol (r = -0.28, NS). These results suggest that the high H-TGL activity in obese women with excess deep abdominal fat could be responsible for the reduction in plasma HDL2 cholesterol levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMedDate not supplied

The effects of exercise-training on energy balance and adipose tissue morphology and metabolism.

The effects of exercise training on energy expenditure, energy intake, fat cell size and adipose tissue lipolysis have been reviewed. Individuals engaged in regular and intense training programmes, e.g. long distance runners, seem to exhibit an elevated resting metabolic rate but moderate training is not accompanied by any important change. Diet-induced thermogenesis is a significant component of daily energy expenditure. It is still unclear whether or not exercise or training causes significant alteration in the thermic response to food intake. Energy expenditure associated with physical activity can play a meaningful role in body composition and adipose tissue metabolism. Largest weight losses have been achieved with programmes of long duration, presumably without marked compensation in food intake. However, it has been shown repeatedly that an increase in energy expenditure with exercise training tends to be associated with an elevation in food intake in free-living individuals. Weight loss is concomitant with a reduction in fat cell diameter and, when caused by an exercise training programme, it is generally accompanied by an increase in fat cell lipolytic activities. There are clear indications that weight loss induced by exercise training has a much higher fat content than weight loss caused by dieting. In addition, data suggest that exercise training may result in a greater depletion of fat stores than a low calorie diet, thus delaying the advent of the resistance phase to fat loss. Data on human subjects derived from well controlled energy balance and metabolic experiments are needed to further advance our understanding about the effects of exercise training on the adipose tissue.

Adipose Tissue↗