Anthropometric, metabolic, psychosocial, and dietary characteristics of overweight/obese postmenopausal women with a history of weight cycling: a MONET (Montreal Ottawa New Emerging Team) study.

Characteristics of weight cyclers have not been fully assessed. The objective of this study was to determine the anthropometric, metabolic, psychosocial, and dietary profile of postmenopausal women according to weight-cycling history, defined as the frequency of going on a diet and losing >10 kg: never (0 times), low (1 time), moderate (2 to 3 times), or frequent (> or = 4 times). The sample of this cross-sectional study consisted of 121 overweight/obese postmenopausal women enrolled in a 6-month randomized weight-loss intervention between 2003 and 2006. Measures at baseline were used to evaluate body composition (fat mass by dual-energy x-ray absorptiometry and visceral fat by computed tomography); resting metabolic rate by indirect calorimetry; insulin sensitivity by hyperinsulinemic-euglycemic clamp; fasting plasma levels of glucose, lipids, leptin, ghrelin, and adiponectin; blood pressure; psychosocial profile (eg, body-esteem, self-esteem, stress, perceived risks, perceived benefits, self-efficacy, quality of life, dietary restraint, disinhibition, hunger); and dietary profile (3-day food record). Differences among groups of weight cyclers were determined using analyses of variance. Among the 121 women, 15.7%, 24.8%, 33.9%, and 25.6% were non-, low, moderate, and frequent cyclers, respectively. Frequent cyclers were characterized by higher body mass index (calculated as kg/m(2)) (current and at 25 years of age) and percent body fat mass, larger waist circumference, and lower resting metabolic rate/kg body weight than noncyclers (P<0.05); and moderate cyclers had lower plasma adiponectin values than noncyclers (P<0.05). For psychosocial measures, frequent cyclers were characterized by greater disinhibition and lower body esteem after controlling for body mass index (P<0.05). In conclusion, weight cycling was found to be associated with some unfavorable metabolic and psychosocial parameters.

Psychosocial correlates of cardiorespiratory fitness and muscle strength in overweight and obese post-menopausal women: a MONET study.

The purpose of this study was to examine the psychosocial correlates of cardiorespiratory fitness (VO2peak) and muscle strength in overweight and obese sedentary post-menopausal women. The study population consisted of 137 non-diabetic, sedentary overweight and obese post-menopausal women (mean age 57.7 years, s = 4.8; body mass index 32.4 kg.m(-2), s = 4.6). At baseline we measured: (1) body composition using dual-energy X-ray absorptiometry; (2) visceral fat using computed tomography; (3) insulin sensitivity using the hyperinsulinaemic-euglycaemic clamp; (4) cardiorespiratory fitness; (5) muscle strength using the leg press exercise; and (6) psychosocial profile (quality of life, perceived stress, self-esteem, body-esteem, and perceived risk for developing chronic diseases) using validated questionnaires. Both VO2peak and muscle strength were significantly correlated with quality of life (r = 0.29, P < 0.01 and r = 0.30, P < 0.01, respectively), and quality of life subscales for: physical functioning (r = 0.28, P < 0.01 and r = 0.22, P < 0.05, respectively), pain (r = 0.18, P < 0.05 and r = 0.23, P < 0.05, respectively), role functioning (r = 0.20, P < 0.05 and r = 0.24, P < 0.05, respectively), and perceived risks (r = -0.24, P < 0.01 and r = -0.30, P < 0.01, respectively). In addition, VO2peak was significantly associated with positive health perceptions, greater body esteem, and less time watching television/video. Stepwise regression analysis showed that quality of life for health perceptions and for role functioning were independent predictors of VO2peak and muscle strength, respectively. In conclusion, higher VO2peak and muscle strength are associated with a favourable psychosocial profile, and the psychosocial correlates of VO2peak were different from those of muscle strength. Furthermore, psychosocial factors could be predictors of VO2peak and muscle strength in our cohort of overweight and obese sedentary post-menopausal women.

Association of acylated ghrelin profiles with chronic inflammatory markers in overweight and obese postmenopausal women: a MONET study.

OBJECTIVE: Recent reports have suggested that the existence of associations between hormonal dysregulation and chronic upregulation of inflammatory markers, which may cause obesity-related disturbances. Thus, we examined whether acylated ghrelin (AcylG) and total ghrelin (TotG) levels could be associated with the following inflammatory markers: C-reactive protein (CRP), tumor necrosis factor alpha (TNF-alpha), and soluble TNF receptor 1 (sTNF-R1). DESIGN: Cross-sectional study consisting of 50 overweight and obese postmenopausal women. METHODS: AcylG and TotG levels were assessed at 0, 60, 160, 170, and 180 min of the euglycemic/hyperinsulinemic clamp (EHC). We evaluated insulin sensitivity, body composition, and blood lipid profiles as well as fasting concentrations of CRP, TNF-alpha, and sTNF-R1. RESULTS: In fasting conditions, sTNF-R1 was negatively correlated with AcylG (r = -0.48, P < 0.001) levels. In addition, AcylG/TotG was associated negatively with sTNF-R1 (r = -0.44, P = 0.002) and positively with TNF-alpha (r = 0.38, P = 0.009) values. During the EHC, TotG (at all time points) and AcylG (at 60 and 160 min) values were significantly decreased from fasting concentrations. AcylG maximal reduction and area under the curve (AUC) values were correlated to sTNF-R1 (r = -0.35, P = 0.02 and r = -0.34, P = 0.02, respectively). Meanwhile, the AcylG/TotG AUC ratio was associated negatively with sTNF-R1 (r = -0.29, P < 0.05) and positively with TNF-alpha (r = 0.36, P = 0.02). Following adjustments for total adiposity, sTNF-R1 remained correlated with fasting and maximal reduction AcylG values. Similarly, AcylG/TotG ratios remained significantly correlated with sTNF-R1 and TNF-alpha. Importantly, 23% of the variation in sTNF-R1 was independently predicted by fasting AcylG. CONCLUSION: These results are the first to suggest that both fasting and EHC-induced AcylG profiles are correlated with fasting values of sTNF-R1, a component of the TNF-alpha system. Thus, AcylG may act, at least in part, as one mediator of chronic inflammatory activity in human obesity.

Association of acylated and nonacylated ghrelin with insulin sensitivity in overweight and obese postmenopausal women.

OBJECTIVE: Ghrelin [acylated (AG) and nonacylated (NAG)] has been shown to play a pivotal role in the regulation of food intake and insulin sensitivity. It is presently unclear whether variation in insulin sensitivity is related to AG and NAG levels in obese individuals. To address this issue, we determined whether insulin-sensitive overweight or obese (ISO) and insulin-resistant overweight or obese (IRO) individuals display different total ghrelin (TotG), AG, and NAG profiles during a euglycemic/hyperinsulinemic clamp (EHC). DESIGN: Eighty-nine nondiabetic overweight and obese postmenopausal women underwent EHC to evaluate insulin sensitivity. Body composition and blood lipid profiles were assessed. Subjects within the highest tertile of insulin sensitivity were described as ISO (n = 31), whereas those within the lowest tertile of insulin sensitivity were considered as IRO (n = 29). Plasma TotG, AG, and NAG profiles were assessed by RIA at 0, 60, 160, 170, and 180 min during the EHC. RESULTS: TotG and NAG levels were significantly decreased for ISO and IRO individuals during the EHC, whereas only ISO subjects displayed a significant reduction of AG concentrations (P < 0.05). AG area under the curve value and the ratio of AG/NAG (fasting and area under the curve) were significantly decreased in ISO individuals. Furthermore, maximal reduction of TotG and AG concentrations was greater in ISO compared with IRO individuals (P < 0.05). Insulin sensitivity was significantly correlated with maximal reduction of TotG (r = 0.36; P < 0.01) and AG (r = 0.36; P < 0.05) concentrations. CONCLUSION: The dysregulation of ghrelin secretion profiles during EHC is associated with insulin resistance. AG may contribute to the variation of insulin sensitivity in overweight or obese postmenopausal women.