Effects of Gene Variation on Exercise-Induced Weight Loss, Body Composition and Fat Distribution in Obese Males

Abstract

Gene variants have an important role in weight loss but no study has examined their association with large exercise-induced weight loss in obesity. The genotypes of Apo E, Lpl hind, Lpl PVU, Cetpataq and UCP 3 have been associated with inter-individual differences in body composition and fat distribution. PURPOSE: Gene variants were associated with body composition and fat distribution changes during large exercise-induced weight loss in obese males. METHODS: 28 obese males (age 19.3 + 1.6 yrs)(BMI 32.9 + 4.2)were evaluated for 4-months prior to basic military training (BMT) to provide control data. These subjects were then examined before (pre-training) and after (post-training) BMT, and 4-months following the completion of training (final).The pre-training, post-training, pre-post and final training variables were analyzed for possible association with gene variants. Fat free mass (FFM), fat mass (FM) and % fat were were determined by DEXA. Fat distribution was determined from a CT scan taken at the level of the L4-L5 vertebrae. BMI and WHR were calculated from height, weight and circumferences using standard methods. Differences between pre-, post - and final training responses were analyzed with a paired t-test. Gene association was analyzed with general linear models. RESULTS: Following BMT subjects lost 13.4 + 3.7 kg (P < 0.001) from pre- to post training which was attributable to reductions in both FM (89%, P < 0.001) and FFM (11%, P<0.01).WC and HC decreased (P < 0.01), and there were equivalent reductions in CT measured IA fat (41%, P < 0.001) and abdominal subcutaneous fat (43%, P < 0.001) depots. When differences between pre- and post-training were associated with gene variants, results indicated there was no significant relations in APO E, LPL hind, LPL PVU, Cetpataq and UCP 3 genotypes and weight loss of 13 kg. Other phenotype traits were not significantly related to gene traits except for LPL Hind (Hip Circumference (HC)), LPL PVU (HC and WHR), UCP3 (WHR, subcutaneous fat). CONCLUSIONS: Results suggest an association between fat distribution and gene variants indicating a greater mobilization of upper body fat and a preferential weight loss of fat from this region during weight loss. However, further studies involving subjects undergoing large exercise induced weight loss are needed to confirm this hypothesis.