Biomedical subjects

Simone Lemieux

Publications and source records attributed to Simone Lemieux.

28 records · Page 2Linked to original sources

PubMed2004

Eating behaviours, dietary profile and body composition according to dieting history in men and women of the Québec Family Study.

The purpose of the present cross-sectional study was to compare eating behaviours (cognitive dietary restraint, disinhibition and susceptibility to hunger), dietary profile and physiological variables according to the practice of dieting: current dieting; history of dieting in the 10-year period that preceded the study; no dieting during the same period. Dieting history, anthropometric markers of adiposity, RMR, dietary profile (3 d food record) and eating behaviours (three-factor eating questionnaire) were determined in a sample of 244 men and 352 women. A greater proportion of women (31.8 %) than men (16.8 %) reported that they had been on a diet over the past 10 years (P=0.0001). In both genders, current and past dieters had a higher BMI (P<0.05) than non-dieters and current dieters had lower reported energy intakes than past dieters and non-dieters (only in women) (P<0.05). Current and past dieters also had higher scores for all eating behaviours and their subscales (P<0.05; except for susceptibility to hunger in men) compared with non-dieters (adjusted for age, reported energy intake, percentage of dietary fat, BMI and RMR). Moreover, for each dieting-history category, women had significantly higher scores for cognitive dietary restraint than men (P<0.05). In conclusion, the present study showed that current and past dieters had higher scores for cognitive dietary restraint and disinhibition compared with non-dieters. As disinhibition has previously been associated with a greater risk of subsequent weight gain, interventions aimed at preventing an increase in disinhibition may be promising for long-term weight maintenance.

Adult↗

PubMed2004

Effect of a nutritional intervention promoting the Mediterranean food pattern on electrophoretic characteristics of low-density lipoprotein particles in healthy women from the Québec City metropolitan area.

The objective of the present study was to evaluate the effect of a nutritional intervention promoting the Mediterranean food pattern in free-living conditions on LDL electrophoretic characteristics in a group of seventy-one healthy women, aged between 30 and 65 years. The 12-week nutritional intervention consisted of two courses on nutrition and seven individual sessions with a dietitian. The first course provided information on the Mediterranean food pattern and the second was a cooking lesson. LDL peak particle diameter (LDL-PPD) and cholesterol levels in small (LDL-cholesterol<255 A) and large LDL fractions (LDL-cholesterol>260 A) were obtained by 2-16 % polyacrylamide gel electrophoresis of whole plasma. The sample was divided on the basis of baseline LDL-PPD using tertiles of the distribution (258.4 A and 260.0 A). Among the total sample of women, no significant change in LDL-PPD was observed in response to the nutritional intervention. However, subjects who at baseline were in the first tertile of the LDL-PPD distribution (<258.4 A) showed a significant increase in LDL-PPD and in the proportion of LDL %>260 A in response to the 12-week nutritional intervention (P<0.05). In contrast, LDL-PPD decreased significantly (P=0.007) among women with large LDL particles at baseline (LDL-PPD >260 A) while the proportion of LDL %<255 A and of LDL %>260 A remained unchanged. To conclude, changes in the food pattern, in response to a nutritional intervention promoting the Mediterranean food pattern, were accompanied by beneficial modifications in LDL electrophoretic characteristics in women who were characterised at baseline by smaller LDL particles.

Adult↗

PubMed2004

Neuromedin beta: a strong candidate gene linking eating behaviors and susceptibility to obesity.

BACKGROUND: Obesity is frequently associated with eating disorders, and evidence indicates that both conditions are influenced by genetic factors. However, little is known about the genes influencing eating behaviors. OBJECTIVE: The objective was to identify genes associated with eating behaviors. DESIGN: Three eating behaviors were assessed in 660 adults from the Quebec Family Study with the use of the Three-Factor Eating Questionnaire. A genome-wide scan was conducted with a total of 471 genetic markers spanning the 22 autosomes to identify quantitative trait loci for eating behaviors. Body composition and macronutrient and energy intakes were also measured. RESULTS: Four quantitative trait loci were identified for disinhibition and susceptibility to hunger. Of these, the best evidence of linkage was found between a locus on chromosome 15q24-q25 and disinhibition (P <0.0058) and susceptibility to hunger (P <0.0001). After fine-mapping, the peak linkage was found between markers D15S206 and D15S201 surrounding the neuromedin beta (NMB) gene. A missense mutation (p.P73T) located within the NMB gene showed significant associations with eating behaviors and obesity phenotypes. The T73T homozygotes were 2 times as likely to exhibit high levels of disinhibition (odds ratio: 1.8; 95% CI: 1.07, 2.89; P=0.03) and susceptibility to hunger (odds ratio: 1.9; 95% CI: 1.15, 3.06; P=0.01) as were the P73 allele carriers. Six-year follow-up data showed that the amount of body fat gain over time in T73T subjects was >2 times that than in P73P homozygotes (3.6 compared with 1.5 kg; P <0.05). CONCLUSION: The results suggest that NMB is a very strong candidate gene of eating behaviors and predisposition to obesity.

Adult↗

PubMed2004

What is a normal glucose value? Differences in indexes of plasma glucose homeostasis in subjects with normal fasting glucose.

OBJECTIVE: To evaluate differences in indexes of plasma glucose/insulin homeostasis and cardiovascular disease risk factors among subjects with normal fasting glucose (NFG), impaired fasting glucose, or glucose intolerance. Although individuals with fasting plasma glucose (FPG) concentrations > 5.4 mmol/l but < 6.1 mmol/l have been shown to have an increased risk of developing type 2 diabetes over 5 years, little is known about glucose metabolism abnormalities in this population. RESEARCH DESIGN AND METHODS: We compared insulin secretion and insulin sensitivity using several indexes derived from an oral glucose tolerance test (OGTT) in 668 subjects from the Quebec Family Study who had varying degrees of FPG. RESULTS: There was a progressive decline in indexes of beta-cell function and insulin sensitivity when moving from NFG to type 2 diabetes. Compared with subjects with low NFG (FPG < 4.9 mmol/l), subjects with high NFG (FPG 5.3-6.1 mmol/l) were more insulin resistant (P < 0.01), had higher insulin and C-peptide responses during an OGTT (P < 0.05), and had reduced insulin secretion (corrected for insulin resistance). Subjects with high NFG were also characterized by higher plasma triglyceride levels and reduced HDL cholesterol concentrations and by a smaller LDL particle size. All these differences remained significant, even after adjustment for age, sex, BMI, and waist circumference. In addition, subjects with mid NFG (FPG 4.9-5.3 mmol/l) were characterized by impaired insulin secretion, decreased insulin sensitivity, higher triglyceride concentrations, and lower HDL cholesterol concentrations compared with subjects with low NFG. CONCLUSIONS: Independent of age, sex, and adiposity, there are differences in indexes of plasma glucose/insulin homeostasis and in cardiovascular risk factors among subjects with low, mid, and high NFG, suggesting the presence, in the upper normal glucose range, of abnormalities in glucose homeostasis, which may predispose to type 2 diabetes.

Adolescent↗

PubMed2003

Fish consumption and blood lipids in three ethnic groups of Québec (Canada).

The purpose of this study was to compare fish intake and plasma phospholipid concentrations of n-3 fatty acids, in particular of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), among representative population samples of Québecers, James Bay Cree, and Inuit of Nunavik (Canada). The relationships between these concentrations and cardiovascular disease (CVD) risk factors were also investigated and compared in the three populations. In 1990-1992, the study subjects had participated in the extensive Santé Québec health surveys conducted in southern Québec, James Bay, and Nunavik. Significant differences in levels of CVD risk factors were found among these three populations. Globally, Inuit showed the lowest risk status for CVD compared with Cree and Québecers, despite the high prevalence of cigarette smoking and obesity. Daily fish intakes varied significantly among the three groups, averaging 13, 60, and 131 g for Québecers, Cree, and Inuit, respectively. Concentrations of EPA + DHA in plasma phospholipids were highest among Inuit (8.0%), second-highest among Cree (3.9%), and lowest among Québecers (1.8%). When the three populations were grouped together, there was a positive association between concentrations of EPA + DHA stratified into quartiles and HDL cholesterol, with a significant relation in quartile 4 (EPA + DHA > or = 4.04%). An inverse relation was also found between EPA + DHA and triacylglycerols in quartile 4. Our results indicate that increased consumption of fish as a source of n-3 fatty acids is beneficially associated with levels of HDL cholesterol and triacylglycerols.

Adolescent↗

PubMed2003

Effect of a nutritional intervention promoting the Mediterranean food pattern on plasma lipids, lipoproteins and body weight in healthy French-Canadian women.

The present study examined the effect of a nutritional intervention promoting the Mediterranean food pattern in uncontrolled 'real life' conditions among a group of 77 French-Canadian women. The principal objective was to document changes in the plasma lipid-lipoprotein profile and in body weight that occurred in response to the intervention. The 12-week nutritional intervention included two group sessions, three individual sessions and four 24-h recalls (phone interview) with a registered dietitian. A score based on the 11 components of the Mediterranean pyramid, ranging from 0 to 44 points, was established to evaluate the adhesion to the Mediterranean food pattern. The Mediterranean score increased from 21.1+/-3.6 at baseline to 28.6+/-4.4 after 6 weeks of intervention (P<0.0001) with no further increase at week 12. Small but significant decreases in total cholesterol and apolipoprotein B (apoB) as well as in body mass index (BMI) were observed after 6 weeks of intervention. No significant change in plasma concentrations of high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and triglycerides (TG) were observed in response to the nutritional intervention. In conclusion, a nutritional intervention program promoting the Mediterranean food pattern was effective in modifying food habits of healthy women from the Québec City metropolitan area and resulted in small but significant effects on specific cardiovascular risk factors.

Adult↗

PubMed2003

Relationship between sex hormone-binding globulin levels and features of the metabolic syndrome.

Previous studies have demonstrated that reduced plasma levels of sex hormone-binding globulin (SHBG) are related to alterations in several features of the metabolic syndrome in both men and women. We investigated whether SHBG level was a global predictor of the metabolic syndrome in a sample of 203 men, 173 premenopausal, and 46 postmenopausal women for whom we also obtained a detailed assessment of the metabolic profile, including body composition (hydrostatic weighing), abdominal adipose tissue areas (computed tomography), plasma lipid-lipoprotein levels, and glucose homeostasis (oral glucose challenge). Low SHBG levels were associated with increased total and abdominal adiposity in men as well as in pre- and postmenopausal women. Low SHBG levels were also associated with an altered metabolic profile, especially in premenopausal women. Subjects were subdivided according to the presence of 0, 1 to 2, or 3 or more features of the metabolic syndrome. Twenty-five percent of men were characterized by 3 features or more, whereas most premenopausal women (61.3%) had a healthy metabolic profile (0 features) and 6.9% were characterized by 3 or more features. Most postmenopausal women (54.3%) were characterized by 1 to 2 components of the metabolic syndrome, and 13.0% were characterized by 3 or more components. The proportion of subjects characterized by the metabolic syndrome (3 components or more) was lower in subjects with SHBG values in the upper tertile compared with the lower tertile in both men and premenopausal women (17.7% v 28.4% and 1.7% v 14.0%, respectively). Logistic regression analyses indicated that an SHBG level in the upper tertile was associated with a significant reduction in the probability of being characterized by the metabolic syndrome (odds ratios of 0.35, P =.02 for men and.11, P =.05 for premenopausal women, with the lower tertile as a reference). The logistic regression was not significant in postmenopausal women. These results suggest that plasma SHBG level may represent a significant predictor of the metabolic syndrome in men and premenopausal women.

Abdomen↗

PubMed2003

Eating behaviors and indexes of body composition in men and women from the Québec family study.

OBJECTIVE: To put into relationship the dietary and anthropometric profile of men and women with their eating behaviors (cognitive dietary restraint, disinhibition, and susceptibility to hunger) and to assess whether gender and obesity status influence these associations. RESEARCH METHODS AND PROCEDURES: Anthropometric measurements (including visceral adipose tissue accumulation), dietary profile (3-day food record), and eating behaviors (Three-Factor Eating Questionnaire) were determined in a sample of 244 men and 352 women. RESULTS: Women had significantly higher cognitive dietary restraint and disinhibition scores than men (p < 0.0001). In both genders, scores for disinhibition and susceptibility to hunger, but not for cognitive dietary restraint, were higher in obese subjects than in overweight and nonobese subjects (p < 0.05). Positive correlations were observed between rigid restraint and most of the anthropometric variables studied (0.12 <or= r <or= 0.16). Moreover, in women, flexible restraint was negatively associated with body fat and waist circumference (r = -0.11). Cognitive dietary restraint and rigid restraint were positively related to BMI among nonobese women (0.19 <or= r <or= 0.20), whereas in obese men, cognitive dietary restraint and flexible restraint tended to be negatively correlated with BMI (-0.20 <or= r <or= -0.22; p = 0.10). DISCUSSION: Gender could mediate associations observed between eating behaviors and anthropometric profile. It was also found that disinhibition and susceptibility to hunger are positively associated with the level of obesity. On the other hand, cognitive dietary restraint is not consistently related to body weight and adiposity, whereas rigid and flexible restraint are oppositely associated to obesity status, which suggests that it is important to differentiate the subscales of cognitive dietary restraint. Finally, counseling aimed at coping with disinhibition and susceptibility to hunger could be of benefit for the long-term treatment of obesity.

Adipose Tissue↗

PubMed2002

Cardiovascular disease risk factors and n-3 fatty acid status in the adult population of James Bay Cree.

BACKGROUND: Canadian native populations, which traditionally consume large amounts of fish, have lower rates of mortality from heart disease than do Canadian nonnative populations, which have low fish intakes. Fish oils rich in n-3 fatty acids may have a protective effect against cardiovascular disease (CVD) risk factors. OBJECTIVES: The purposes were to examine the profile of plasma phospholipid concentrations of the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) among James Bay Cree and to verify the relation between these concentrations and CVD risk factors. DESIGN: The study population consisted of 917 subjects aged 18-74 y who participated in the 1991 Santé Québec Health Survey. Data were obtained through home interviews and clinic visits. Plasma samples were analyzed for phospholipid fatty acid composition. RESULTS: The mean fish consumption on the day before the survey was 60 g among the adult Cree population. Expressed as a percentage of total fatty acids, relative concentrations of EPA and DHA were 0.65% and 2.80%, respectively. n-3 Fatty acids were higher among coastal residents than among inland residents. A positive association was observed between plasma HDL and n-3 fatty acids. EPA and EPA+DHA were inversely associated with triacylglycerols. Among subjects aged 50-74 y, an inverse association between EPA and EPA:AA and total:HDL cholesterol was observed. CONCLUSIONS: n-3 Fatty acids may favorably influence some CVD risk factors. The Cree population must be encouraged to maintain their traditional fish-based diet, which may be one of the factors protecting them against mortality from CVD.

Adolescent↗

PubMed1999

Comparison of two techniques for measurement of visceral adipose tissue cross-sectional areas by computed tomography.

Most computed tomography (CT) scanners used today are able to accurately measure adipose tissue (AT) areas at any site of the body. However, first generation CT scanners used by some medical centers are not equipped with appropriate software allowing the measurements of AT areas. The aim of this study was to validate a technique of AT area measurements independent from CT scanner software. Abdominal AT areas were recorded with CT in a sample of 30 men. Areas were thereafter calculated using the standard CT software technique. Total and visceral AT areas were then remeasured using another technique for which X-ray film of each subject's scan was analysed by a system completely independent from the CT scanner (imaging densitometer and NIH image analysis software). Correlations between measurements obtained with the two techniques were very strong for both total (n = 0.99; SEE = 11.7 cm(2)) and visceral AT areas (r = 0.99; SEE = 5.3 cm(2)). Values obtained with the image analysis method were generally higher than with the conventional CT software technique (cross-sectional areas of AT were overestimated by 4.7% for total abdominal and 8.5% for visceral AT respectively). In conclusion, the results indicate that measurements obtained with this image analysis technique would be adequate to correctly rank subjects according to levels of total or visceral AT areas. However, since this method appears to slightly overestimate AT areas, a standardized correction should be performed before comparing subjects with AT areas measured with this technique to subjects whose AT areas have been obtained with the conventional CT software technique. Am. J. Hum. Biol. 11:61-68, 1999. Copyright 1999 Wiley-Liss, Inc.

Journal Article↗