PPARα Gene Is Involved in Body Composition Variation in Response to an Aerobic Training Program in Overweight/Obese.

The objective of this study was to investigate the relationship of the polymorphism in Intron 7 G/C (rs 4253778) of the peroxisome proliferator-activated receptor alpha (PPARα) gene with the magnitude of changes in the body composition of an overweight and obese population that underwent an aerobic training program. Fifty-eight previously inactive men and women, body mass index (BMI) 31.5 ± 2.8 kg/m2, 46.5% (n = 27) genotyped as CC genotype and 53.5% (n = 31) as CA+AA, underwent a 12-week aerobic training (walking/running). Aerobic capacity (ergospirometry), body composition (DXA), and nutritional assessment were made before and 48 h after the experimental protocol. Two-way ANOVA, chi-square test, and logistic regression were used (p < 0.05). Twenty-seven volunteers (46.5%) were identified as CC genotype and 31 (53.5%) as CA+AA genotype. Time-group interaction showed that there was no difference in these between two allele groups. However, differences in distribution of respondents or nonresponders according to allele A were identified for fat mass (p ≤ 0.003), percentage fat mass (p ≤ 0.002), the waist (p ≤ 0.009), abdomen (p ≤ 0.000), and hip (p ≤ 0.001), this difference being independent for the fat mass. Meanwhile, sex, age, and nutritional management have also been found to be influential factors. It is concluded that the PPARα gene is involved in varying body composition in response to an aerobic training program.

Oxidative stress does not influence weight loss induced by aerobic training in adults: randomized clinical trials.

BACKGROUND: High levels of oxidative stress promote degradation of the cell membrane impairing cellular function in fat oxidation. However, the influence of oxidative stress on exercise-induced weight-loss has not yet been investigated. Therefore, the aim of this study was to verify the influence of a lipidic peroxidation marker (malondialdehyde, MDA) and antioxidant status (total antioxidant capacity marker, TAC) on the magnitude of weight-loss by aerobic-induced exercise in previously sedentary overweight or obese individuals. METHODS: Seventy-five physically inactive adults were randomized into experimental (N.=58) and control (N.=17) groups, who engaged in a 12-week program of aerobic training walking and/or running (3 to 5 days/week) or stretching (1 day/week), respectively. Body composition (DXA), aerobic capacity (ergospirometric) and blood collections for oxidative stress analysis (MDA and TAC) were determined before and after the experimental protocol. Two-way ANOVA for repeated measures or Friedman's test were used to evaluate differences in time/group interaction. Pearson correlation was used to verify the relationship between the variables of oxidative stress and of body composition. RESULTS: Significant reduction was found in fat body mass of experimental when compared to control group (-1.3±1.9 kg versus -0.3±1.3, P=0.04). Experimental group also altered significantly the total body mass (-1.2±4.7 kg; effect size 0.44), body mass index - BMI (-0.3±1.1 effect size 0.37), fat percentage (1.3±1.6%; effect size 0.50) and lean body mass (0.6±1.5 kg; effect size 0.32).There was increase in MDA of 2.3 µmol/L to 2.7 µmol/L (P=0.00), without changes to TAC (25.6±13.9% to 28.0±10.4%). No correlation was found between these variations in body composition with either the initial values of MDA and TAC or delta variation of these indicators of oxidative stress in response to the training program. CONCLUSIONS: Indicators of oxidative stress (MDA and TAC) does not influence the magnitude of weight-loss induced by aerobic training.