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Biomedical subjects

C Bouchard

Publications and source records attributed to C Bouchard.

At least 55 records · Page 3Linked to original sources
PubMed1994

Systolic blood pressure during submaximal exercise: an important correlate of cardiovascular disease risk factors in normotensive obese women.

Body fatness, plasma lipids, lipoproteins, indicators of glucose metabolism, and resting as well as submaximal treadmill exercise systolic blood pressures (BPs) were measured in a sample of 25 normotensive obese premenopausal women. No association was observed between body fatness, risk factors for cardiovascular disease, and resting BP. However, body fatness and plasma cholesterol, low-density lipoprotein cholesterol (LDL-CHOL), LDL apolipoprotein B (apo B), and apo B concentrations, as well as the high-density lipoprotein cholesterol to cholesterol (HDL-CHOL/CHOL) ratio, showed significant correlations with systolic BP measured during submaximal exercise. In addition, fasting plasma insulin concentrations and the glucose and insulin areas under the oral glucose tolerance test (OGTT) curve were both significantly associated with systolic BP during submaximal exercise. Partial correlation analyses revealed that the associations between submaximal exercise systolic BP and plasma apo B and LDL apo B levels were in part independent from the level of obesity. These results indicate that plasma concentrations of lipoproteins and insulin are important correlates of the systolic BP during submaximal exercise in obese premenopausal women. Further analyses performed on two subgroups indicated that women with high exercise systolic BP values exhibited significant differences in their metabolic profile in comparison to women with low BP during exercise. These results suggest that the absolute systolic BP recorded during submaximal exercise may be useful in the early detection of individuals at risk for the development of cardiovascular disease in resting normotensive obese women.

Adult↗
PubMed1994

Impact of exercise intensity on body fatness and skeletal muscle metabolism.

The impact of two different modes of training on body fatness and skeletal muscle metabolism was investigated in young adults who were subjected to either a 20-week endurance-training (ET) program (eight men and nine women) or a 15-week high-intensity intermittent-training (HIIT) program (five men and five women). The mean estimated total energy cost of the ET program was 120.4 MJ, whereas the corresponding value for the HIIT program was 57.9 MJ. Despite its lower energy cost, the HIIT program induced a more pronounced reduction in subcutaneous adiposity compared with the ET program. When corrected for the energy cost of training, the decrease in the sum of six subcutaneous skinfolds induced by the HIIT program was ninefold greater than by the ET program. Muscle biopsies obtained in the vastus lateralis before and after training showed that both training programs increased similarly the level of the citric acid cycle enzymatic marker. On the other hand, the activity of muscle glycolytic enzymes was increased by the HIIT program, whereas a decrease was observed following the ET program. The enhancing effect of training on muscle 3-hydroxyacyl coenzyme A dehydrogenase (HADH) enzyme activity, a marker of the activity of beta-oxidation, was significantly greater after the HIIT program. In conclusion, these results reinforce the notion that for a given level of energy expenditure, vigorous exercise favors negative energy and lipid balance to a greater extent than exercise of low to moderate intensity. Moreover, the metabolic adaptations taking place in the skeletal muscle in response to the HIIT program appear to favor the process of lipid oxidation.

Adipose Tissue↗
PubMed1994

[Incidence and characteristics in identification of abused children: cross-cultural comparison].

This study compared the incidence and characteristics of reported child abuse cases in two different ethnic groups. Incidence was calculated based on the total number of cases (N = 2,854) reported to child protection authorities between July 17, 1988 and March 31, 1989. In a sample of 953 reports, the following were examined: the source of the reporting, type of abuse, substantiation and age of the child. The incidence was found to be slightly higher among Haitian group compared to French-Canadian group. In the former case, reporting tended to originate with public authorities such as the police or school personnel. Cases tended to consist mainly of physical abuse, with very few cases of sexual abuse. Most involved adolescents. These results suggest that child-rearing practices of Haitian families are in conflict with the values of the host community, and that there exist similar value-based conflicts between Haitian parents and their children.

Adolescent↗
PubMed1994

Mechanism of inhibition of lipopolysaccharide-stimulated mouse B-cell responses by transforming growth factor-beta 1.

Transforming growth factor-beta 1 (TGF beta 1) is a pleiotropic cytokine which inhibits growth of many cell types and positively or negatively regulates the production of Ig isotypes. By using mouse resting B cells stimulated by lipopolysaccharide (LPS), we investigated whether the effect of TGF beta 1 on Ig production is related to its effect on cell growth. We show that low doses of TGF beta 1 stimulate IgG3 and IgG2b production whereas higher doses inhibit IgM, IgG3, IgG1 and IgG2b secretion and cell proliferation. TGF beta 1 titration curves and kinetics experiments suggested that the inhibitory effect on Ig secretion and B-cell growth are closely related. We defined the phase at which TGF beta 1 exerts its anti-proliferative effect on mouse B cells. TGF beta 1 does not modify the increase in expression of class II antigens which occurs before transition from G0 to G1. However, it partially inhibits the induction of expression of low-affinity Fc gamma RII and cell enlargement which both begin during the early G1 phase, and it totally blocks induction of the expression of transferrin receptors, a marker of the late G1 phase. Thus, TGF beta 1 blocks LPS-stimulated mouse B cells in the early G1 phase, and this results in inhibition of Ig production.

Animals↗
PubMed1994

Prognostic significance of early cardiac index measurements in severely burned patients.

Invasive monitoring during early resuscitation was performed. To compare the heamodynamic results of severely burned patients, the results of 38 patients hospitalized between 1988 and 1991 in the burn centre of Lyon were retrospectively reviewed. Survivors and non-Survivors' data were compared. No difference existed between the two groups in age, unit burn score, fluid requirement and dose of dobutamine. Survivors had a significantly higher cardiac index, O2 delivery and systolic blood pressure index than non-survivors. It is suggested that the ability to sustain a high cardiac index in response to the burn injury plays a role in the outcome of the patients. There is an indication that dobutamine could have a beneficial effect in this way. Further studies are needed to confirm the benefit of the maintenance of high cardiac index levels by the pressors.

Adult↗
PubMed1994

Modulation of 5-HT release in the guinea-pig brain following long-term administration of antidepressant drugs.

1. The aims of the present study were to determine whether long-term 5-hydroxytryptamine (5-HT) reuptake blockade and inhibition of type-A monoamine oxidase (MAO-A) lead to an enhancement of the electrically evoked release of tritum from guinea-pig brain slices preloaded with [3H]-5-HT, and to assess the sensitivity of the terminal 5-HT1D autoreceptor, the alpha 2-adrenoceptor also located on 5-HT terminals, and the 5-HT3 receptor that modulates 5-HT release following these two types of antidepressant treatments. 2. The electrically evoked release of tritium was significantly enhanced following a 21-day treatment with the 5-HT reuptake blocker, paroxetine and the reversible MAO-A inhibitor, befloxatone, in preloaded slices of the hypothalamus, hippocampus and frontal cortex 48 h after removal of the osmotic minipumps used to deliver the drugs. 3. The inhibitory effect of the terminal 5-HT autoreceptor agonist, 5-methoxytryptamine, on the evoked release of tritium was attenuated in slices of the hypothalamus, hippocampus, but not frontal cortex, following the paroxetine treatment. In the befloxatone group, the effectiveness of 5-methoxytryptamine was unaltered in the same brain structures. 4. The sensitivity of the alpha 2-adrenoceptor on 5-HT terminals, assessed using UK 14.304, was attenuated in hypothalamus, hippocampus, but not frontal cortex slices prepared from befloxatone-treated guinea-pigs and preloaded with [3H]-5-HT. The paroxetine treatment did not alter the sensitivity of this alpha 2-adrenoceptor in the hypothalamus. 5. The sensitivity of the alpha 2-adrenoceptor on noradrenaline terminals, also assessed using UK 14.304, was not altered in hippocampus and hypothalamus slices preloaded with [3H]-noradrenaline following the long-term befloxatone treatment. 6. In frontal cortex slices, [3H]-5-HT uptake was no longer significantly attenuated after a 21-day treatment with paroxetine, whereas it was still markedly inhibited in hypothalamus slices. The enhancing effect of paroxetine on the evoked release of [3H]-5-HT in the superfusion medium was no longer evident in frontal cortex slices of the paroxetine group. These data indicate that long-term 5-HT reuptake blockade desensitized the 5-HT transporter in the frontal cortex. 7. The capacity of the 5-HT3 receptor agonist, 2 methyl-5-HT, to enhance the electrically evoked release of tritium was not altered in hypothalamus, hippocampus, and frontal cortex slices prepared from befloxatone-treated guinea-pigs, but was significantly attenuated in the paroxetine group also treated for 21 days. Following a 2-day paroxetine treatment, the enhancing effect of 2-methyl-5-HT on tritium release was unaltered in frontal cortex slices.

Animals↗
PubMed1994

Population evaluations of health related fitness from perceptions of physical activity and fitness.

The possibility of predicting health related fitness using questions on occupational and leisure activity was explored in 172 men and 178 women. ANOVA and multiple regression equations related questionnaire responses to objective fitness measures including body mass index, circumferences, skinfolds, body fat, blood glucose, uric acid, total cholesterol, HDL-cholesterol and triglycerides, PWC150, blood pressures, and resting heart rate. Reported occupational activities bore little relationship to health related fitness. Self-perceptions of moderately frequent and moderately intense leisure activity, plus at least average perceived fitness relative to age-matched peers, were associated with a favorable body fat content and lipid profile, whereas indicators of cardiovascular health (a low resting heart rate and a high PWC150) were linked with perceptions of frequent and intense activity, plus a perceived fitness level higher than that of a peer reference group. Based on these findings, a simple scoring of reported activity for use in fitness counseling is suggested.

Adult↗
PubMed1994

Principal components of fitness: relationship to physical activity and lifestyle.

Interrelationships between metabolic and cardiorespiratory health were examined in 350 healthy adults. Four principal components accounted for 66.7% of the variance in 172 males (M) and for 62.4% in 178 females (F). Factor 1, "obesity," related to body mass index, abdominal circumference, total skinfold thickness, and (M only) abdominal/hip circumference ratio. Factor 2, "cardiovascular fitness," had loadings from resting heart rate and PWC150/kg. Factors 3 and 4 were related to total cholesterol and HDL-cholesterol, respectively (plus blood pressures, particularly in F). Factor 1 was linked to caffeine consumption and to exercise frequency (F) or perceived intensity (M). Factor 2 was linked to perceptions of activity relative to others (M and F) and to the intensity of activity (M only). Factors 3 and 4 were associated with perceived fitness and physical activity relative to others. Because perceptions of physical activity and fitness lack consistency, it is suggested that health be judged more directly from simple measures of health related fitness that require little subject cooperation.

Adult↗
PubMed1994

ApoB-100 gene EcoRI polymorphism. Relations to plasma lipoprotein changes associated with abdominal visceral obesity.

The aim of this study was to investigate whether the EcoRI restriction fragment length polymorphism (RFLP) of the apolipoprotein (apo) B-100 gene influences the associations described among obesity, regional adipose tissue distribution, and plasma lipoprotein levels. For this purpose, blood samples were collected from 56 healthy men for whom we had extensive measurements of regional adipose tissue distribution (both anthropometric and computed tomography-derived measurements) and data on the plasma lipoprotein-lipid profile. DNA was extracted from white blood cells, and RFLP analysis was performed. Subjects were classified into two groups on the basis of their apoB-100 EcoRI genotype: subjects homozygous for the major 11-kb allele, the 11/11 group (n = 40), and subjects carrying the minor 13-kb allele, the 13/11 group (n = 16). Subjects carrying the 13-kb allele had lower percent body fat and abdominal adipose tissue accumulation than subjects homozygous for the 11-kb allele (P < .05). Although leaner, the 13/11 group did not show a more favorable plasma lipoprotein-lipid profile than the group homozygous for the 11-kb allele. In fact, after statistical control for the difference in percent body fat between the two genotype groups, the 13/11 group showed significantly higher plasma cholesterol levels (P < .05) and nearly significantly higher apoB levels than the 11/11 group (P = .06). The association patterns between indices of regional adiposity and plasma cholesterol and apoB levels were also different between the two EcoRI genotype groups. Only in the 13/11 group was the abdominal visceral adipose tissue area significantly associated with these plasma variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

DNA variation in the genes of the Na,K-adenosine triphosphatase and its relation with resting metabolic rate, respiratory quotient, and body fat.

The aim of this study was to investigate in 261 subjects from 58 families the association between DNA variation at the genes coding for the Na,K-ATPase peptides and resting metabolic rate (RMR), respiratory quotient (RQ), and percent body fat (%FAT). Five restriction fragment length polymorphisms (RFLP) at three Na,K-ATPase genes were determined: one at the alpha 1 locus (BglII), and two at the beta locus (beta MspI and beta PvuII). Haplotypes were determined from the two variable sites of the alpha 2 gene (alpha 2 haplotypes) and the beta gene (beta haplotypes). There was a strong trend for %FAT to be related to the RFLP generated by BglII at the alpha 2 exons 21-22 in males (P = 0.06) and females (P = 0.05). RQ was (a) associated with the BglII RFLP at the alpha 2 exon 1 (P = 0.02) and with the alpha 2 8.0 kb/4.3 kb haplotype (P = 0.04) and (b) linked with the beta gene MspI marker (P = 0.04) and with the beta 5.3 kb/5.1 kb haplotype (P = 0.008) based on sib-pair analysis. The present study suggests that the genes encoding Na,K-ATPase may be associated or linked with RQ and perhaps with %FAT but not with RMR.

Adipose Tissue↗
PubMed1994

Thyroid hormones and thyrotropin variations during long term overfeeding in identical twins.

The aim of this study was to evaluate variations in plasma thyroid hormones and TSH during a standardized long term overfeeding protocol (4.2 megajoules/day [corrected] during a 100-day period) in 24 lean adults (12 pairs of monozygotic twins) and to assess their relationships with body composition and resting metabolic rate (RMR) changes. Compared to preoverfeeding values, basal plasma T3 concentrations were increased on day 25, but not later; basal plasma T4 and free T4 (FT4) concentrations were unchanged; basal plasma rT3 concentrations were persistently decreased throughout the entire protocol; and the TSH response to TRH stimulation was persistently enhanced. The TSH response to TRH before overfeeding was positively correlated with the changes in RMR with overfeeding (r = -0.53; P < 0.01). No association was found between changes in basal plasma T3 concentrations and changes in RMR. However, changes in basal T3 were positively related to changes in body weight (r = 0.46; P < 0.05). A significant within-pair similarity was found for changes in T4 and FT4 with overfeeding (P < 0.05). We conclude that 1) during overfeeding, the early increase in T3 concentrations is a transitory phenomenon, whereas the decrease in rT3 concentrations and the increased TSH response to TRH are more sustained; 2) the TSH responsiveness to TRH stimulation could be a predictor of the changes in RMR during times of increased energy intake; 3) there is no evidence for a direct role of T3 in the adaptation of resting energy expenditure during a long term overfeeding protocol; and 4) the genotype could be involved in the changes in T4 and FT4 during a prolonged positive energy balance period.

Adult↗
PubMed1994

DNA polymorphism in the uncoupling protein (UCP) gene and human body fat.

The objective of this study was to identify DNA sequence variation in the UCP gene and to investigate its relationship with some obesity phenotypes. Two studies were carried out: (1) association study in unrelated subjects, and (2) sib-pair linkage analysis study in brothers and sisters. The subjects were 261 individuals from the Québec Family Study (123 parents and 138 offsprings from 64 families). The following were measured: Body mass index, percent body fat (measured by hydrostatic weighing), and subcutaneous fat (estimated by the sum of 6 skinfolds) were measured in 1978-81 and again 12 years later. Resting metabolic rate (RMR) was measured only in 1989-93. Genetic analyses were performed using Southern blotting technique and a human UCP genomic probe. (1) A BcII restriction fragment length polymorphism was identified with two alleles of 8.3 and 4.5 kb in length, and respective frequencies of 0.28 and 0.72. (2) In unrelated adults from the parental generation, a cross-sectional analysis of the 1989-93 data showed no difference in body fat and RMR between the UCP genotypes. No significant difference for the absolute changes in body fat over the 12-year period among the UCP genotypes was observed. However, a higher frequency (P < 0.05) of the 8.3-kb allele was found in high gainers compared to low gainers (i.e., above and below the median value) for percent body fat over the 12-year period. (3) No evidence of linkage between any of the obesity phenotypes and the UCP BcII marker was found. For the first time, the presence of DNA polymorphism in the human UCP gene is reported. Although, no significant association and linkage were found between the UCP BcII gene marker and body fat in the cohort of the Quebec Family Study, a higher frequency of the 8.3-kb allele was found in individuals who gained more body fat over time.

Adipose Tissue↗
PubMed1994

Cross-trait familial resemblance for body fat and blood pressure: familial correlations in the Québec Family Study.

Cross-trait resemblance between body fat and blood pressure (BP) was examined among families in the Québec Family Study by using a bivariate familial correlation model assessing both intraindividual (e.g., comparison of father's body fat with his own BP) and interindividual (e.g., comparison of father's body fat with son's BP) cross-trait correlations. Each of six body-fat measures-(i) percent body fat, (ii) body-mass index, (iii) the sum of six skinfolds, (iv) the ratio of the sum of six skinfolds to total fat mass, (v) the ratio of the trunk skinfold sum to the extremity skinfold sum, and (vi) the regression of the trunk-extremity skinfold ratio on the sum of six skinfolds--was analyzed separately with systolic BP and with diastolic BP. Results showed that (1) upper-body fat was the strongest interindividual correlate of BP (especially the correlation of trunk-extremity ratio with diastolic BP), suggesting shared pleiotropic genetic and/or common familial environmental effects; (2) summary body-fat measures either were inconsistent (in the case of both percent body fat and sum of six skinfolds) or gave no evidence of interindividual cross-trait resemblance with BP (in the case of body-mass index); and (3) intraindividual resemblance between the sum of six skinfolds and BP largely vanished once the skinfold sum was adjusted for fat mass, suggesting that the intraindividual association may be mediated largely by the absolute amount of subcutaneous fat rather than by the subcutaneous proportion. Finally, the magnitude of the spouse resemblance for the trunk-extremity ratio with diastolic BP suggests that a significant proportion of the resemblance may be due to environmental influences. In summary, our investigation confirms a heritable link between BP and truncal-abdominal fat as predicted by the metabolic-syndrome hypothesis. That this result is obtained in primarily normotensive, nonobese families, suggests the connection involves normal metabolic paths.

Adipose Tissue↗
PubMed1994

Twin resemblance in somatotype and comparisons with other twin studies.

Twin resemblance in somatotype components was considered in 28 male and 34 female monozygotic (MZ) twin pairs and 19 male and 21 female dizygotic (DZ) twin pairs, 9.3-23.5 years of age. The Heath-Carter anthropometric somatotype method was used. Mean somatotypes of male twins and female twins did not differ, whereas male twins were significantly more mesomorphic than female twins. Twin resemblance was evaluated in two ways: first, treating each somatotype component independently of the other two (as in earlier twin studies), and, second, looking at resemblance in each somatotype component after statistically controlling for the other two components (thus treating the somatotype as a composite). Intraclass correlations were consistently higher in MZ than in DZ twins of both sexes, and within-pair variances were consistently lower in MZ than in DZ twins of both sexes. However, after controlling for the effects of the other two somatotype components, within-pair variances of male MZ and DZ twins for each somatotype component did not differ. In general, Heath-Carter anthropometric somatotype components show (1) significant resemblance in MZ and DZ twins within each sex, although the degree of resemblance is altered in male twins when a different analytic strategy is used, (2) no sex difference in degree of resemblance, and (3) greater resemblance within MZ twin pairs than within DZ twin pairs. These results are compatible with the presence of genetic variation affecting physique in adolescents and young adults.

Adolescent↗
PubMed1994

The natural history of obesity in an obese population and associations with metabolic aberrations.

The natural history of obesity was examined in a nation-wide sample of 1,084 obese men and 1,367 obese women aged 37-59 years who were recruited into a registry of potential subjects for an intervention trial. The registry and intervention studies are jointly referred to as SOS ('Swedish Obese Subjects'). In the registry, the mean body mass index was 37.7 kg/m2 in men and 40.9 kg/m2 in women. Descriptive information on subjects' weight histories and the relative weights of their biological parents was collected by means of a self-administered questionnaire. At a physical examination shortly thereafter, weights, heights and selected cardiovascular risk factors were measured in the fasting state. Virtually all subjects reported weight loss attempts in the past, men and women reported having gained weight during adulthood at a considerably higher rate than that observed in population-based samples. Significant correlations were observed between relative weights of obese males and both of their biological parents, but not between obese women and either of their parents. Indices of medical risk were then examined in relation to individual weight histories. Familial predisposition did not relate to most aspects of current medical risk. However, later-onset obesity tended to be associated with greater cardiovascular risk, while prior weight loss was predictive of an improved risk factor profile. These latter associations were not dependent on a subject's current degree of obesity and were particularly consistent with respect to fasting insulin level.

Adult↗
PubMed1994

Vulvar vestibulitis syndrome: an exploratory case-control study.

OBJECTIVE: To assess the prevalence of genital bacterial infection among women with vulvar vestibulitis syndrome and to evaluate the association of several potential risk factors with the occurrence of the syndrome. METHODS: Fifty-seven women referred for dyspareunia who satisfied Friedrich's criteria and had symptoms for at least 6 months were recruited as cases. Controls included 173 patients without dyspareunia seen at a private clinic. Cases and controls were aged 18-35 years and were not pregnant. RESULTS: Among cases, the prevalences were low for genital infection with gonorrhea (0%), Chlamydia (0%), Trichomonas (0%), Mycoplasma (0%), Gardnerella (14%), and Candida (8.8%). Ureaplasma was detected in the Bartholin glands of ten affected women (17.5%). Human papillomavirus DNA was detected in only three cases (5.3%) based on polymerase chain reaction assays on vestibular biopsies. The relative risk (RR) of the syndrome was related to some aspects of sexual and reproductive history. In particular, the RR in women who had used oral contraceptives (OCs) early (before age 17) reached 11.0 (95% confidence interval [CI] 1.3-97.1) relative to those who had never used OCs. Women who had first intercourse at age 15 or earlier had a 3.3-fold increase in RR (95% CI 1.4-8.0) compared to those who had first intercourse at age 16 or later. CONCLUSION: Our data provide little support for the idea that infection causes the vulvar vestibulitis syndrome. Hormonal factors such as early OC use may be involved in the etiology of this condition.

Adolescent↗