Khanna D, C Baetge, S Simbo, B Lockard, E Galvan, Y.P. Jung, M Koozehchian, R Dalton, M Byrd, C Rasmussen, M Greenwood, RB Kreider*
Abstract: Resistin and visfatin are secreted by adipose tissue and are potential regulators of inflammation and insulin sensitivity. This study examined the effects of exercise and diet-induced weight loss on resistin and visfatin. Twenty six sedentary obese women were randomly assigned into a non-exercise and diet intervention control group (C) or a diet plus exercise group (DE) that involved adherence to a 1,200 kcal/day for 1 week and 1,500 kcal/d diet for 11 weeks (45% protein, 30% fat) while participating in a supervised circuit resistance-exercise (4 d/week) with walking (10,000 steps/d, 3 d/week). Body composition and fasting blood samples were obtained at 0 and 12 weeks and analyzed by multivariate, univariate, and repeated measures General Linear Model analysis and bivariate Pearson product correlation analysis. Data are presented as mean±SD changes from baseline. Participants in the DE group lost more weight (DE: -5.9±4.0; C: 0.6±1.4 kg, p<0.001), fat mass (DE: -5.1±4.5; C: 0.4±1.5 kg, p<0.001) and body fat percentage (DE: -3.4±3.3; C: 0.2±1.9 kg, p=0.002) with significant decreases in insulin (DE: -8.5±15.0; C: 0.1±7.7 IU/ml, p=0.07, ηp2 = 0.13), IL-6 (DE: -1.9±4.2; C: 2.7±1.2 ng/ml, p=0.001), TNFα (DE: -0.2±2.1; C: 1.7±1.5 ng/ml, p<0.01), and leptin (DE: -19.8±21.9; C: 4.5±16.0 ng/ml, p=0.003) while tending to prevent decreases in visfatin (DE: 0.9±15; C -20.1±37 ng/ml, p=0.10, ηp2 = 0.10). No effects were seen on glucose (DE: -3.8±19.8; C: -2.8±6.9 mg/dl, p=0.87) and resistin levels (DE: 18.6±100; C: 59.9±162 ng/ml, p=0.45). Changes in resistin significantly correlated with IL-6 and visfatin. Linear regression analysis revealed significant correlations between changes in resistin to visfatin (r=0.42, R2=0.174, p=0.034) and resistin to IL-6 (r=0.43, R2=0.185, p=0.028). Results support contentions that diet and exercise-induced weight loss affects insulin sensitivity and inflammatory markers and that changes in resistin and visfatin may be correlated with some of these changes.
Keywords: Resistin, Visfatin, Exercise, Weight Loss, Diet