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C Bouchard

Publications and source records attributed to C Bouchard.

At least 523 records · Page 29Linked to original sources
PubMed1988

Effect of the amount of body fat on the age-associated increase in serum cholesterol.

This study investigates the contribution of body fat stores on the age-associated increase in serum cholesterol and triglyceride levels. Percentage of body fat was measured by hydrostatic weighing, and serum cholesterol, triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels were determined in a sample of 472 healthy men and women ages 18-50 years. In both sexes, body fat mass was significantly correlated with serum cholesterol (r = 0.21 in men and r = 0.24 in women, P less than 0.01) and triglyceride (r = 0.33 in men and r = 0.24 in women, P less than 0.01) levels. After adjustment for the association between age and serum cholesterol, no correlation was observed between body fat mass and serum cholesterol (r = 0.01 in men and r = 0.09 in women). After correction for age, serum triglyceride levels remained significantly correlated with body fat mass (r = 0.26 and r = 0.17 in men and women, respectively, P less than 0.05). As body fat also increases with age, the possibility that a partial correlation coefficient procedure eliminated a portion of the age effect mediated by an age-related increase in fat, was addressed by performing further analyses. Within each sex subsample two sets of analyses were performed on (a) three groups of subjects individually paired for age but with different levels of body fat stores, and (b) three groups of subjects paired for the amount of body fat but differing in age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1988

Relationships between body fatness, adipose tissue distribution and blood pressure in men and women.

The relationships between body fatness, fat distribution and blood pressure (BP) were studied in 234 women and 238 men, aged 18-50 years. In both sexes, subcutaneous (s.c.) fat (assessed by the measurement of s.c. skinfolds) and percent body fat (measured by underwater weighing) were correlated significantly with diastolic (0.27 less than or equal to r less than or equal to 0.37, p less than 0.0005) and systolic (0.17 less than or equal to r less than or equal to 0.29, p less than 0.01) BP. In either sex, the proportion of s.c. trunk fat as reflected by the ratio of trunk/extremity skinfolds showed significant associations with diastolic (men: r = 0.35, women: r = 0.20, p less than 0.01) and systolic BP (men: r = 0.15, women: r = 0.17, p less than 0.05). Control for the effects of covariables potentially affecting BP (energy intake, energy expenditure, maximal oxygen consumption, cigarette smoking, alcohol intake and age) revealed significant effects of age and alcohol intake on BP in men. In women, only age appeared to be associated with BP variation. Partial correlations after control for age and alcohol intake indicated a significant association between the trunk/extremity skinfolds ratio and diastolic BP in men. Such a correlation was not found in women after control for the effect of age. Analysis of variance (2 x 2 factorial with fixed effects) confirmed that, in men, the distribution of s.c. body fat was, per se, associated with diastolic BP (F = 8.43, p less than 0.01), whereas the proportional of s.c. trunk fat was not related to systolic BP in both sexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1988

Estimation of the contribution of the various energy systems during maximal work of short duration.

The aim of this experiment was to estimate the relative contribution of the various energy delivery systems during maximal exercise tests of short duration. Twenty-five males were submitted to a VO2max test and 10-, 30-, and 90-s maximal ergocycle tests. Expiratory gases were collected with a Douglas bag during the entire 30-s test and continuously monitored with an open-circuit system during the 90-s test. Estimates of the phosphagenic component represented approximately 55%-60% of the energy expenditure during the 10-s work performance. Results of the 30-s test indicated that the relative contributions of the energy systems were 23%, 49%, and 28% for the phosphagenic, glycolytic, and oxidative pathways, respectively. For the 90-s test, these estimates were 12%, 42%, and 46% for the three metabolic systems. The highest contribution of each system during the 90-s was obtained from 5 to 15 s for the phosphagenic component, from 16 to 30 s for the glycolytic, and from 61 to 75 s for the aerobic energy systems. During the 90-s test, VO2max was reached after approximately 60 s. It is concluded that the 30 and 90 s are not strictly anaerobic although they all have a large anaerobic component.

Adult↗
PubMed1988

Familial resemblance in energy intake: contribution of genetic and environmental factors.

Total energy intake and intakes of carbohydrate, fat, and protein as well as the percentage of energy derived from these nutrients were calculated from a 3-d dietary record in 1597 subjects living in 375 families of French descent. Familial correlations were computed in pairs of biological relatives and relatives by adoption and used in the path-analysis BETA model to determine the contribution of genetic and nongenetic factors in the familial resemblance observed in energy intake. No significant genetic effect was found for intake of any nutrient tested (h2 less than or equal to 11%) and cultural inheritance was found to be more important than genetic inheritance. Nontransmitted environmental factors, including home environmental effects, were found to account for more than 50% of the variation observed in the energy-intake components. These results suggest that the average genetic influence on nutrient intake is negligible and that nongenetic effects associated mainly with home environmental effects are the major affecters of energy intake.

Adolescent↗
PubMed1988

Condyloma and intraepithelial neoplasia of the uterine cervix: a case-control study.

Cervical condyloma and cervical intraepithelial neoplasia are related to human papillomavirus infections, some of which may be involved in the etiology of cancer of the uterine cervix. This case-control study was designed to assess the relation of age at first sexual intercourse, number of sexual partners, and cigarette smoking to the risk of cervical condyloma and cervical intraepithelial neoplasia. Cases and controls were premenopausal women under age 50 years who had been referred for examination at the Colposcopy Clinic of Saint-Sacrement Hospital in Quebec from 1982 to 1985. These were 136 cases of histologically confirmed cervical condyloma and 247 cases of cervical intraepithelial neoplasia. The 137 controls were women without anogenital condyloma, dysplasia, or carcinoma. Information on personal characteristics and exposures of subjects was obtained by interview. Associations observed with age at first intercourse were different for condyloma and cervical intraepithelial neoplasia. Relative risk of condyloma varied little with age at first intercourse. In contrast, relative risk of cervical intraepithelial neoplasia increased as age at first intercourse decreased. For the two types of lesions, relative risk was elevated among women with more than one sexual partner and increased steadily with increasing number of cigarettes smoked per day. The association with cigarette smoking was, however, somewhat stronger for cervical intraepithelial neoplasia.

Adult↗
PubMed1988

Genetic factors in the regulation of adipose tissue distribution.

This paper reviews current data concerning the role of the genotype in human variation in fat distribution and its contribution in regulating fat deposition in various regions of the body, primarily the lower trunk area. After statistical control over age, gender and total amount of subcutaneous fat, one finds an additive genetic effect of about 20-25% of remaining human variance in amount of lower trunk fat and in the relative proportion of lower trunk versus extremity fat. In spite of such a moderate genetic effect in fat distribution, the preferential site of fat deposition when exposed to chronic overfeeding is largely determined by one's genotype. Characteristics of regional adipose tissue metabolism and morphology are probably involved in mediating some of these genetic effects but other regulatory mechanisms are undoubtedly implicated.

Abdomen↗
PubMed1988

Physical training and changes in regional adipose tissue distribution.

Obesity has been associated with numerous metabolic complications, such as changes in the concentration and/or composition of plasma lipoproteins, glucose intolerance and hyperinsulinemia leading to diabetes and hypertension. The relation of obesity to cardiovascular disease has not, however, been consistently reported. Recent prospective studies have clearly indicated that the distribution of adipose tissue was a significant cardiovascular risk factor and numerous studies have shown that metabolic disturbances were more closely associated with the level of abdominal fat than excess adiposity per se. As obese men generally store their energy excess in the abdominal region and women in the peripheral fat depots, the metabolic complications of obesity seem to be more closely related to adiposity in men than in women. It is suggested that the sex dimorphism observed in adipose tissue localization could partly explain the greater cardiovascular risk associated with obesity in men than in women. Indeed, obese women with a "male" (abdominal) distribution of body fat have greater metabolic complications than women with lower body fat. When aerobic exercise-training is used to induce weight loss, men generally lose more fat than women. In men, the loss of adipose tissue appears to be central, potentially reducing the risk of cardiovascular disease, whereas a relative resistance to fat loss is observed in women compared to men. Although resistance to fat loss is noted in women, those with a "male" distribution of adipose tissue (high waist-to-hip ratio and high intra-abdominal fat deposition) and with associated metabolic complications greatly benefit from aerobic exercise-training.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1988

Heredity and body fat.

The genetics of human obesity was reviewed here in terms of studies dealing with body fat and fat distribution. The role of heredity was examined by reviewing genetic disorders in which obesity is a clinical feature. Two kinds of genetic effects were discussed: the additive genetic effect and the genotype-environment interaction effect. Several indicators of body fat exist, including body mass index, amount of subcutaneous fat, percentage body fat, fat mass, regional fat distribution, and subcutaneous fat pattern. A low additive genetic effect of less than 10% of human phenotypic variation is found in body mass index and amount of subcutaneous fat, while percentage body fat, fat mass, fat distribution, and fat patterning are characterized by heritability estimates of about 25%. On the other hand, a recent study demonstrates that there is an important genotype-environment interaction effect in human body fat variation induced by overfeeding. Limitations of current approaches to the study of the genetics of human body fat and obesity are considered and comments are offered concerning promising areas of future research.

Adipose Tissue↗
PubMed1988

Abdominal adipose tissue and serum HDL-cholesterol: association independent from obesity and serum triglyceride concentration.

It has been recently shown that an excess of abdominal fat was associated with reduced serum HDL-cholesterol level, supporting previous studies that have reported a relationship between fat distribution and cardiovascular risk factors. Since a negative relationship has been observed between serum triglyceride and HDL-cholesterol concentrations, the associations between body fat distribution and HDL-cholesterol level was studied with control over serum triglycerides in a sample of 429 healthy adult men. The relative distribution of subcutaneous fat, as reflected by the trunk to extremity skinfolds (T/E) ratio and the absolute amount of subcutaneous abdominal fat, obtained by the measurement of the abdominal skinfold thickness, were significantly correlated with serum triglycerides (r = 0.27 and 0.35 respectively, P less than 0.0001), with serum HDL-cholesterol (r = -0.14, P less than 0.01, and -0.26, P less than 0.0001) and with the serum HDL-cholesterol/total cholesterol ratio (r = -0.25 and -0.39, P less than 0.0001). Analysis of variance on two factors, the T/E ratio and the body mass index (BMI), revealed significant and independent effects of adiposity and relative distribution of subcutaneous fat on serum lipids and HDL-cholesterol (0.05 greater than P less than 0.001). However, when comparable analyses of variance were performed to study the respective contributions of obesity (as measured by the BMI) and the absolute amount of abdominal fat (as measured by the abdominal skinfold), most of the variance in serum triglycerides, cholesterol and HDL-cholesterol was explained by abdominal fat alone and not by the BMI. Therefore, it appeared that with the exception of the HDL-cholesterol/total cholesterol ratio, the association between obesity and serum lipids and HDL-cholesterol was, in the present sample, primarily explained by the amount of abdominal fat. As reported by others, serum triglyceride level was negatively correlated with HDL-cholesterol (r = -0.33, P less than 0.0001) and the HDL-cholesterol/total cholesterol ratio (r = -0.54, P less than 0.0001). After cholesterol and HDL-cholesterol scores were adjusted for the effect of triglycerides, the T/E ratio was no longer associated with serum HDL-cholesterol whereas the abdominal skinfold remained significantly correlated with serum HDL-cholesterol concentration (r = -0.16, P less than 0.01). These results suggest that a portion of the association between body fat topography and serum HDL-cholesterol is mediated by the effect of fat distribution on serum triglycerides.(ABSTRACT TRUNCATED AT 400 WORDS)

Abdominal Muscles↗
PubMed1988

Sensitivity to overfeeding: the Quebec experiment with identical twins.

The role of the genotype in the response to short-term overfeeding was assessed by submitted six pairs of male monozygotic twins to a 4.2 MJ (1000 kcal) per day energy intake surplus for a period of 22 consecutive days. Individual differences in fat mass and fat-free mass gains were observed in response to overfeeding but they were not randomly distributed. Indeed, the within-pair resemblance in the response was striking when compared to the heterogeneity found among the pairs in adiposity and fat-free mass gains. The intrapair resemblance in the response to overfeeding as assessed by the intraclass coefficient computed with the individual changes, reached 0.88 for total fat mass and 0.76 for fat-free mass. A similar trend for a genetically determined pattern of adaptation to overfeeding was observed for resting metabolic rate (intraclass = 0.63), thermic effect of a meal (intraclass = 0.62), and energy cost of submaximal exercise (intraclass = 0.78) when the data were analysed in terms of changes in oxygen uptake. On the other hand, no major alterations in glucose and insulin response to a glucose load or a test meal, in cardio-pulmonary adaptation to submaximal exercise and in maximal exercise tolerance were found with overfeeding. In contrast, the response of suprailiac fat cell lipolysis (intraclass of about 0.7) and heparin releasable adipose tissue lipoprotein lipase (intraclass - 0.82) varied among individuals but was highly homogeneous within genotypes. Similarly, a genotype-overfeeding interaction effect was seen for serum triglycerides (intraclass = 0.69), HDL-cholesterol (intraclass = 0.85), and the HDL-cholesterol to total cholesterol ratio (intraclass = 0.82). Multiple correlation analyses suggest that much of the variance in the response of fat mass (R = 0.65) and fat-free mass (R = 0.81) is accounted for by alterations in the energy expenditure components assessed in the study. If one takes into account the measurement errors always present in such complex studies and the fact that only a limited fraction of the energy expenditure of activity was considered by design, one can conclude that the genotype determines to a large extent the response variation to short-term overfeeding. In particular, the genotype-overfeeding interaction effect for body composition changes seems to be mediated by the various energy expenditure components, themselves characterized by significant genotype-overfeeding interaction effects.(ABSTRACT TRUNCATED AT 400 WORDS)

Adipose Tissue↗
PubMed1988

Effect of a three-day interruption of exercise-training on resting metabolic rate and glucose-induced thermogenesis in training individuals.

Exercise-training has been shown to influence resting components of energy expenditure in lean and obese individuals. Moreover, experimental data suggest that the effect of training on these components could represent an acute effect of exercise. In this regard, the present study was undertaken to determine whether resting metabolic rate (RMR) and glucose-induced thermogenesis (GIT) could be modified depending on the delay elapsing between the last exercise session of a training program and calorimetric measurements. Eight trained individuals were tested 16 h after a 90-min exercise bout and following a 3-day interruption of training. A significant decrease in RMR (-6.6 percent, P less than 0.05) was observed in response to exercise cessation. On the other hand, an increased GIT was noted following the 3-day rest period and this effect was also statistically significant. These results show that short-term interruption of training can affect substantially RMR and GIT in trained individuals, indicating that the time elapsing since the last exercise session must be taken into account in the interpretation of the effects of physical training on both these parameters.

Basal Metabolism↗
PubMed1988

Genetic basis of racial differences.

The purpose of this paper is (a) to present brief historical notes on the concept of race, (b) to define race in the context of evolutionary biology, (c) to quantify the extent of human genetic variation, (d) to estimate genetic differences within and between races, and (e) to comment on the implications of these concepts for racial differences in sport performance. Research shows that genetic variation in gene products and in the non-coding sequence of DNA is quite extensive in humans. Variation is found more frequently in non-coding DNA sequences than in coding exons, and while this variation does not influence the primary structure of the proteins, it may have considerable impact on gene expression. However, much of that genetic variation is shared by all human beings, and only about 10% is specific to races or populations within races. At this time, it is not possible to conclude satisfactorily the significance of these modest racial differences in genetic variation for racial differences in performance. It may turn out that this low level of genetic heterogeneity may have considerable implication for performance.

Genetic Variation↗
PubMed1988

Racial variation in work capacities and powers.

Large interindividual variation in work capacities and powers are often reported in the literature. The variations are attributed to such varied factors as age, sex, exercise training, and heredity, among others. Ethnic/racial origin as a putative causal factor of such variations has also been considered. Studies of subjects from various countries report aerobic power generally between 40 and 50 mL O2/kg.min-1, with a mean around 45 mL. Differences between groups are generally small and genuine racial differences in maximal aerobic power are lacking when allowance is made for other factors. There are, on the other hand, differences between racial groups in submaximal work efficiency and endurance performance. These differences, however, appear to result from differences in mechanical efficiency owing to test mode and/or level of habituation to the ergometer. Performances on maximal tests of short duration demonstrate some variation among racial groups, but again differences in mechanical efficiency cannot be ruled out. Thus there does not appear to be valid and reliable evidence to support the concept of clear racial differences in work capacities and powers.

Adolescent↗
PubMed1988

A comprehensive nutrition case management system.

An innovative, state-of-the-art, comprehensive nutrition assessment and case management system has been developed by nutritionists (R.D.s) and public health nurses with the San Bernardino County Public Health Department in California. The system consists of three major components: flowsheets for the infant, the child, the perinatal client, family planning, and the adolescent/adult/aging client; a manual that defines and describes nutrition assessment guidelines and interventions; and an appendix that includes resource/reference information. Distinct advantages and unique features of this system include the following: (a) decrease in charting time; (b) precise documentation; (c) a workable diagnostic tool for implementing nutrition interventions; (d) a standard for consistent, quality nutrition care; (e) computer adaptability; and (f) easy accessibility for quality assurance audits.

Age Factors↗
PubMed1988

Isokinetic strength training protocols: do they induce skeletal muscle fiber hypertrophy?

Sedentary subjects were submitted to repeated concentric isokinetic strength training protocols separated by a 50-day detraining period. Peak torque output of the quadriceps muscle group increased by 54% after the first ten-week training protocol. No significant changes in mean skeletal muscle fiber area were observed while a significant increase in percent fiber type and percent fiber area was noticed for type IIa fibers. The activities of the enzymes hexokinase, malate dehydrogenase, 3-hydroxyacyl CoA dehydrogenase, and oxoglutarate dehydrogenase were also increased significantly. Fifty days without training induced a significant decline in peak torque output. All the enzymes that responded to the first training protocol maintained their elevated activities over the detraining period except for the enzyme oxoglutarate dehydrogenase. A second training protocol administered to the same subjects following the 50-day inactivity period did not result in any significant increase in maximum torque output and fiber area. It is concluded that the isokinetic strength training protocol used can increase the functional capacity of skeletal muscle, but this effect does not appear to be related to skeletal muscle fiber hypertrophy.

Adult↗
PubMed1988

Inter-generation transmission of physical fitness in the Canadian population.

Body weight, height, body mass index, skinfold measurements, waist-to-hip ratio (WHR), somatotype components, muscular endurance and strength, flexibility, resting heart rate and submaximal power output (PWC150/kg) were measured in 13,804 subjects during the 1981 Canada Fitness Survey. Familial correlations were computed to determine the contribution of transmissible (t2) and environmental (e2) factors in physical fitness by path analysis. Transmissibility estimates (t2) under 0.30 for weight, height, WHR and PWC150/kg, above 0.40 for mesomorphy, ectomorphy, push-up test and flexibility, and between 0.30 and 0.40 for the other measurements were obtained. These results suggest that e2 account for more than 50% of the variation and that the average total biological and cultural inheritance from parents to offspring in physical fitness of Canadians accounts for 30% to 40% of the phenotypic variation.

Adolescent↗