HIIE and Abdominal Fat Mass in DT2 Postmenopausal Women

Overview

Postmenopausal women, as men, are more prone to central or android obesity. Abdominal fat mass is associated with an increase of cardiovascular diseases (CVD). In type 2 diabetic (T2D) patients, the risk of CVD mortality is more than double compared with that in age-matched subjects. Most exercise programs designed for weight loss have focused on steady-state exercise (SEE) of around 30 min at a moderate intensity several times a week. Disappointingly, these kinds of exercise programs have led to little or no fat loss (Shaw et al. 2006). Accumulating evidence suggests that high intensity intermittent exercise (HIIE) has the potential to be an effective exercise protocol for reducing fat of overweight individuals, especially at the abdominal level (Boutcher 2011, Kessler 2012). Despite these results, HIIE program has never been used in TD2 postmenopausal women to favor a specific decrease of abdominal fat mass. The aim of our study was to compare the effects of 16-week steady-state exercise (SSE) program with high intensity intermittent exercise (HIIE) program on total abdominal and visceral fat mass in T2D postmenopausal women. It is hypothesized that HIIE compared to SSE program would result in significantly greater reductions in total abdominal and visceral fat mass.

Overweight and obesity levels have escalated worldwide, and these trends are occurring in both developed and developing countries. Fat mass and more precisely abdominal fat mass is linked to the development of cardio-vascular diseases (CVD). Postmenopausal women, as men, are more prone to central or android obesity. In type 2 diabetic (T2D) patients, the risk of CVD mortality is more than double compared with that in age-matched subjects. Most exercise programs designed for weight loss have focused on steady-state exercise (SEE) during at least 30 min, 2 or 3 times a week. Disappointingly, these kinds of exercise programs have led to little or no fat loss (Shaw et al. 2006). Accumulating evidence suggests that high intensity intermittent exercise (HIIE) has the potential to be an effective exercise protocol for reducing fat of overweight individuals, especially at the abdominal level (Boutcher 2011, Kessler 2012). HIIE involves brief high-intensity, anaerobic exercise followed by brief but slightly longer bouts of very low-intensity exercise. The aim of our study was to compare the effects of 16-week steady-state exercise (SSE) program with high intensity intermittent exercise (HIIE) program on total abdominal and visceral fat mass in T2D postmenopausal women. 30 T2D postmenopausal women will be randomly assigned to SSE (n= 15) or HIIE (n= 15) group. Subjects performed two sessions by week, on bicycle, during 16 weeks. SSE: For the SSE protocol, each subject performed 40 min at 50% MAP (maximal aerobic power) HIIE: For the HIIE protocol, each subject performed 8 s of sprinting and 12 s of turning the pedals over slowly (between 20 and 30 r.p.m.) for a maximum of 60 repeats a session. Total body and regional fat content will be measured using dual-energy x-ray absorptiometry (DXA) before and after the intervention (4 months). The contribution of visceral fat to total abdominal fat will be determined from computed tomography (CT). The effects of HIIE and SSE program on: * Total fat mass (and appendicular fat mass) (DXA) * Total fat free mass (and appendicular fat free mass) (DXA) * Glycemic profile (plasma HbA1c, plasma glucose) * Lipid profile (TG, HDL, LDL, total cholesterol) * Food behavior after training (questionnaires) will also be compared. Gaussian distribution of the data will be tested by the Kolmogorov-Smirnov test. Data will be presented as mean ± standard deviation (SD). Comparisons between groups will be made with Mann \& Whitney U test or ANOVA when appropriate. Relationships between data will be assessed by Pearson correlation. Significance will be accepted at the p\<0.05 level. Statistical procedures will be performed using Statistica.