Showing papers by "Claude Bouchard published in 1983"

Familial resemblance in fatness indicators

Abstract: Family resemblance in fatness has been studied in 481 individuals from 114 families of French descent living in the greater Quebec city area. Subjects were measured for the following fatness indicators: triceps, biceps, subscapular, suprailiac, abdominal and medial calf skinfolds. The sum of these six skinfolds as well as a prediction of percent body fat (Durnin and Rahaman 1967) were also considered. Data were standardized for appropriate age and sex classes yielding SS scores. The influence of relevant lifestyle variables (energy intake, energy expenditure and socioeconomic status) were statistically removed from SS yeilding residual scores (RS) that were then submitted to familial analyses. Analyses of variance indicate that there is a larger between family variation than within (P less than or equal to 0.01) for SS when considering either the whole nuclear family or sibships; in these instances, the intra-class correlation ranges from 0.15 to 0.26. There was, however, no significant resemblance among spouses for the SS fatness indicators. Similar values were essentially found for RS fatness indicators. Furthermore, husband-wife inter-class correlations were not significant with the exception of subscapular and calf skinfold RS. Covariations between biological relatives are however significant (0.16 less than or equal to r less than or equal to 0.24, P less than or equal to 0.01) for SS and remain essentially unchanged after statistical control over the lifestyle variables (0.16 less than or equal to r less than or equal to 0.40, P less than or equal to 0.01). The findings that spouses do not covary significantly in fatness, while biological relatives of traditional nuclear families exhibit a significant degree of resemblance even after statistical control over daily energy intake, daily energy expenditure and socioeconomic status provide evidence supporting the hypothesis that there is a substantial genetic effect in human fatness.

Association between serum high-density lipoprotein cholesterol and body composition in adult men

Abstract: The relationships between measurements of body composition and fasting serum high-density lipoprotein cholesterol (HDL-C) were assessed in 357 men aged 30 to 59 years. The sum of six skinfolds (triceps, biceps, subscapular, suprailiac, abdominal and medial calf), body density through underwater body weighing, lean body mass (kg), body-fat mass, and percent body fat, all three derived from the Siri equation, were obtained. Effects of age, sex, alcohol consumption, cigarette smoking, socioeconomic status, triglycerides, total cholesterol and current energy expenditure were statistically removed through multiple regression procedures. HDL-C was significantly associated with weight, weight/height, weight/height11, weight/height16, body density, body-fat mass, sum of six skinfolds, but not with height alone or lean body mass. These results suggest that, among the body composition measurements, the adipose component is the major contributor to the low but significant association between HDL-C and weight.

Adipocyte diameter and lipolytic activity in marathon runners: Relationship with body fatness

Abstract: Fifteen highly trained marathon runners gave their consent to participate in a study designed to investigate the effects of exercise-training on adipose tissue morphology and metabolism. They were submitted to an adipose tissue biopsy in the suprailiac region and their results were compared with an age and weight matched control group. As expected, runners were characterized by a lower percent body fat. They also had a significantly smaller mean fat cell diameter. Moreover, runners had significantly higher basal, epineprine sub-maximal, and epinephrine maximal stimulated lipolysis than controls. \(\dot VO_2\) max and body fatness were significantly correlated to adipocytes lipolysis. However, when seven runners were paired for mean fat cell diameter and percent body fat with seven sedentary control subjects, no differences in lipolytic activities were observed. These results indicate that high adipose tissue lipolytic activity is associated with low percent body fat in highly trained endurance runners.

Familial resemblance in catecholamine changes to cold stress and maximal exercise.

Abstract: Parents and children from 38 families were submitted to a cold-stress and maximal treadmill test. The number of subjects varied depending on the measurements. Plasma epinephrine and norepinephrine, blood pressure and heart rate were measured before, during and after a cold hand immersion test (in a water bath at 5 degrees C for 2 min), as well as before and after maximal exercise (modified Balke). Scores were adjusted for the effects of age and sex through multiple-regression procedures (age + sex + age X sex + age2 + age3), yielding residuals which were submitted to analysis. Characteristic variations during cold stress were observed. Maximal exercise yielded a mean aerobic power of 43 ml/kg min-1 (SD = 10), a mean maximal heart rate of 192 (SD = 10) and a mean maximal blood lactate of 65 mg/100 ml (SD = 23). Family resemblances in cold stress and maximal exercise adaptive reactions were investigated by comparison of between-family over within-family means of squares. In response to the cold stress, there were indications of family lines in induced changes for systolic blood pressure, epinephrine, and total catecholamines at 1 min after the test (p less than or equal to 0.05). Furthermore, parent-child correlations were significant and reached 0.38 for epinephrine, 0.28 for norepinephrine, and 0.34 for total catecholamines. Familial concentrations could not be detected before or 8 min after the cold stress. There are no indications of family resemblance in plasma catecholamine concentrations following exposure to maximal-exercise stress. It is concluded that genetic variation is probably contributing only moderately to catecholamine changes under cold stress and very little under exercise stress.