Relationships between serum omentin-1 concentration, body composition and physical activity levels in older women

This study aimed to investigate the relationships between omentin-1, body composition and physical activity (PA) levels in older women. Eighty-one older women (age = 64 ± 6years; body mass index = 24.2 ± 3.2 kg/m(2); body fat percentage = 36.1 ± 5.7%) participated in this study. We divided the subjects into overweight/obesity and normal weight group. Body composition was measured by dual energy X-ray absorptiometry. Serum omentin-1 concentration was measured using enzyme linked immunosorbent assay. PA levels were obtained by using accelerometers. In addition, anthropometric and insulin resistance values were determined. Omentin-1 level in overweight/obesity group was significantly lower than in the normal weight group (P < .01). Analysis of all subjects showed that serum omentin-1 was negatively correlated with body weight, BMI (body mass index), waist circumference (WC), WHR (waist-to-hip ratio), percentage of body fat, total body fat mass (FM), fat-free mass (FFM) (r = −.571, −0.569, −0.546, −0.382, −0.394, −0.484, −0.524, all P < .01), respectively. We also found a negative correlation between moderate-to-vigorous physical activity (MVPA) and total body FM (r = −.233, P < .05). However, no significant correlation was found between omentin-1 and sedentary behavior and MVPA (both P > .05). Moreover, the relationship between omentin-1, body composition and PA was analyzed by using multiple linear stepwise regressions. The results showed that serum omentin-1 concentration was inversely correlated with total body FM (β = −0.334, P = .004) in multiple linear stepwise regression analysis. We found that total body FM was inversely related to serum omentin-1 concentration and PA levels, but there was no correlation between omentin-1 and PA levels. These results showed that PA may participate in the regulation of body composition, which may be also affected by serum omentin-1. However, the mechanism by which PA affects body composition may not be through omentin-1 and was more likely through other metabolic pathways.