Pro12Ala Polymorphism on the PPAR γ 2 Gene and Weight Loss After Aerobic Training: A Randomized Controlled Trial

The objective of this study was to verify the influence of the Pro12Ala polymorphism of the PPARγ2 gene in response of a training program on the body composition. Sixty-nine previously inactive men and women (32.8 ± 8.2 years) were genotyped and underwent a 12-week aerobic (running/walking) training program (3-5 sessions, 40 - 60 min per session, and intensity between the aerobic and anaerobic threshold) (experimental group = 53) or were part of the control group ( = 16). They were tested for aerobic capacity (ergospirometry), body composition (DXA), abdomen, waist and hip circumferences and nutritional assessment before and 48 h after the experimental protocol. Two-way repeated measures ANOVA test was used to verify possible differences in variables between the experimental vs. control groups or Pro/Pro vs. Pro/Ala groups, and the Chi-squared test was used to verify the distribution of responders and non-responders according to genotype ( < 0.05). Frequencies of 75.5% Pro/Pro ( = 40) and 24.5% Pro/Ala ( = 13) were found, without any occurrence of the recessive homozygote. Body fat reduction was initially confirmed compared to a control group which did not exercise ( = 16; 29.1 ± 8.8 years), so that the exercise group obtained a reduction of -1.3 kg vs. -0.3 kg in the control group ( = 0.03). When they were divided by genotype, there were significant changes in fat mass (-1.3 ± 2.1 kg; = 0.00), lean mass (0.6 ± 1.5 kg; = 0.02), fat percentage (-1.3 ± 1.6; = 0.00), waist circumference (-2.2 ± 2.9 cm; = 0.00), abdomen circumference (-3.3 ± 3.6 cm; = 0.00) and hip circumference (-2.7 ± 2.7 cm; = 0.00) for Pro/Pro genotypes; and fat mass (-1.1 ± 1.7 kg; = 0.04), fat percentage (-0.9 ± 1.5; = 0.04), abdomen circumference (-3.9 ± 3.5 cm; = 0.00) and hip circumference (-1.8 ± 1.8 cm; = 0.00) for Pro/Ala genotypes, without any group interaction differences. The Chi squared test revealed no differences in the distribution of responders or non-responders according to genotype. It is concluded that an aerobic training program promotes weight loss, but the Pro12Ala polymorphism in the PPARγ2 gene does not influence the variability of aerobic-induced exercise weight loss.