Gauthier M.-S.,Institute Of Recherches Cliniques Of Montreal |
Rabasa-Lhoret R.,Institute Of Recherches Cliniques Of Montreal |
Rabasa-Lhoret R.,University of Montreal |
Rabasa-Lhoret R.,University of Ottawa |
And 5 more authors.
Journal of Clinical Endocrinology and Metabolism
Context: Although obesity is strongly linked to insulin resistance and type 2 diabetes, a subset of obese individuals termed metabolically healthy but obese(MHO)appears relatively protected from the development of cardiometabolic complications. The origins of this metabolically healthy phenotype remain unclear. Recently, persistent organic pollutants (POPs) have emerged as potential endocrine disruptors. Objective: The aim of this study was to test the hypothesis that theMHOphenotype presents lower circulating levels of POPs as compared to the metabolically abnormal obese (MAO) phenotype. Design, Setting, and Patients:Weconducted a cross-sectional study of 76 nondiabetic obese (body mass index ≥30 kg/m2) postmenopausal women. Main Outcome Measures: Plasma concentrations of 21 POPs as well as cardiometabolic risk factors were analyzed. Results: For similar age, body mass index, and fat mass index, MHO women (n 40) showed higher insulin sensitivity levels and a more favorable cardiometabolic profile than MAO women (n = 36), as evidenced by a 2-fold increase in glucose disposal rates measured by the hyperinsulinemic-euglycemic clamp (P = .001). Among 18 detectable pollutants measured, MAO women had higher plasma concentrations of 12 POPs (fold increase, 1.4-2.9; P<.001-.036). Logistic regression analyses showed that the prevalence of the MAO phenotype was significantly associated with higher levels of total dioxinand non-dioxin-like polychlorinated biphenyls (odds ratio, 4.7; 95% confidence interval, 1.8-12.5; P= .002), as well as trans-nonachlor (odds ratio, 6.1; 95% CI, 2.2-16.4; P < .001). Conclusion: Our study demonstrates that the metabolically healthy and abnormal phenotypes have distinct plasma POP profiles. © 2014 by the Endocrine Society. Source
Changes in glucose disposal after a caloric restriction-induced weight loss program in obese postmenopausal women: Characteristics of positive and negative responders in a Montreal-Ottawa New Emerging Team study
Myette-Cote E.,Universite de Sherbrooke |
Doucet E.,University of Ottawa |
Prud'Homme D.,University of Ottawa |
Prud'Homme D.,Institute Of Recherche Of Lhopital Montfort |
And 4 more authors.
Objective: This study aims to investigate individual characteristics that explain interindividual variations in glucose disposal in response to a 6-month weight loss program in obese postmenopausal women.Methods: The cohort was divided into tertiles based on changes in glucose disposal after weight loss. Only women in the upper tertile (positive responders: Δglucose disposal ? 0.92 mg/kg/min; n = 19) and lower tertile (negative responders: Δglucose disposal ≤ -0.23 mg/kg/min; n = 19) were considered for analyses. Outcome measures included body weight, lean body mass (LBM), LBM index (= LBM / height [m]), fat mass (FM), FM index (= FM / height [m]), visceral fat, subcutaneous abdominal fat, high-sensitivity C-reactive protein (hsCRP) levels, interleukin-6, lipid profile, physical activity levels, fasting blood glucose and insulin levels, glucose disposal by hyperinsulinemic-euglycemic clamp technique, and resting blood pressure.Results: At baseline, positive responders had higher triglycerides and hsCRP levels and lower glucose disposal (0.01 < P < 0.05) than negative responders. Except for visceral fat, the entire cohort showed significant decreases in all measures of body composition (P < 0.005) after weight loss, with greater decreases in body weight, body mass index, and FM index in positive responders (P < 0.005). Finally, data revealed that only positive responders showed decreases in LBM, LBM index, and hsCRP levels after weight loss (P between 0.01 and 0.001).Conclusions: An important interindividual variability in changes in glucose disposal after weight loss is observed. Interestingly, participants who display improvements in glucose disposal also show significant decreases in LBM, LBM index, and hsCRP after weight loss. © 2014 by The North American Menopause Society. Source
Gavarry O.,University of Toulon |
Aguer C.,Institute Of Recherche Of Lhopital Montfort |
Delextrat A.,Oxford Brookes University |
Lentin G.,Unite Mediterraneenne de Nutrition |
And 2 more authors.
Journal of Sports Sciences
Abstract: The purpose of this study was to determine the substrate oxidation rate and the exercise intensity at which maximal lipid oxidation and ventilatory threshold (VT) occur in obese (BMI: 36.6 ± 6.3 kg · m−2) and normal-weight adolescent girls (BMI: 18.7 ± 1.6 kg · m−2) aged 14–18 years. Substrate oxidation rate was determined by gas exchange using an incremental field test involving walking. Body composition was assessed by bioelectrical impedance. Carbohydrate oxidation rates were significantly higher in obese than in normal-weight girls at speeds ranging from 4 to 6 km · h−1 (P < 0.05), whereas no significant differences were observed between groups regarding lipid oxidation rates. The crossover point of substrate utilisation and the VT were significantly lower in obese than in normal-weight adolescents (P < 0.05). Maximal lipid oxidation rate was observed at 46 ± 15 and 53 ± 15 %E (Formula presented.) O2max in obese and normal-weight adolescents, respectively. At these intensities, the Lipoxmax was significantly lower in obese than in normal-weight girls (6.7 ± 2.3 versus 8.9 ± 3.5 mg · min−1 · kg−1 FFM, P < 0.05, 95% CI: −3.7 to −0.7, d = −0.74). The present results have implications in designing interventions to promote lipid oxidation and energy expenditure during walking in severely obese adolescent girls. © 2015 Taylor & Francis. Source
Pal S.,University of Ottawa |
Blais J.M.,University of Ottawa |
Robidoux M.A.,Indigenous |
Haman F.,Indigenous |
And 5 more authors.
Diabetes and Metabolism
Aims: Recent evidence suggests an association between persistent organic pollutants (POPs) and type 2 diabetes. In two First Nations communities where wild food is consumed by a large portion of the population, we compared pollutants in plasma between diabetic and non-diabetic individuals, and investigated the strength of association between pollutants and insulin resistance/secretion in non-diabetic individuals. Methods: The study population consisted of 72 participants. Oral Glucose Tolerance Tests were used to assess diabetes status. Plasma was used to determine POP concentrations and mercury concentrations were determined from hair samples. Results: Age-adjusted plasma concentrations of some pollutants were significantly higher in diabetic than in non-diabetic individuals. When taking into account age, adiposity levels, and smoking status, POP levels were not associated with insulin resistance nor with insulin secretion in non-diabetic individuals. Conclusions: These findings confirm that POP concentrations in plasma may be higher in diabetic than in non-diabetic individuals. No association was however seen between POP concentrations and markers of insulin resistance/secretion in non-diabetic individuals. © 2013 Elsevier Masson SAS. Source
Ivanova I.V.,Ottawa Hospital Research Institute |
Tasca G.A.,University of Ottawa |
Hammond N.,Ottawa Hospital |
Balfour L.,University of Ottawa |
And 4 more authors.
European Eating Disorders Review
This study evaluated the validity of the interpersonal model of binge-eating disorder (BED) psychopathology in a clinical sample of women with BED. Data from a cross-sectional sample of 255 women with BED were examined for the direct effects of interpersonal problems on BED symptoms and psychopathology, and indirect effects mediated by negative affect. Structural equation modelling analyses demonstrated that higher levels of interpersonal problems were associated with greater negative affect, and greater negative affect was associated with higher frequency of BED symptoms and psychopathology. There was a significant indirect effect of interpersonal problems on BED symptoms and psychopathology mediated through negative affect. Interpersonal problems may lead to greater BED symptoms and psychopathology, and this relationship may be partially explained by elevated negative affect. The results of the study are the first to provide support for the interpersonal model of BED symptoms and psychopathology in a clinical sample of women. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association. Source