Genetic variations of leptin and leptin receptor are associated with body composition changes in response to physical training.

Leptin regulates body weight, metabolism, and tissue adaptations to environmental stressors. We examined the association of single nucleotide polymorphism (SNP) of leptin promoter G-2548A (rs7799039) and leptin receptor Gln223Arg (rs1137101) with body composition, plasma leptin levels, and peak oxygen uptake (VO(2)peak) in response to 8 weeks of physical training in 48 male military conscripts. AA homozygotes of leptin promoter SNP-2548 showed higher body fat and BMI values than G allele carriers. Acute exercise decreased leptin levels in G allele carriers, but increased in AA homozygotes. Physical training significantly decreased BMI values and also a tendency for decreased plasma leptin levels was observed in all subjects. In G allele carriers, BMI loss was mainly due to decreased fat mass, whereas in AA homozygotes due to loss of fat-free mass. Training increased VO(2)peak in all subjects with most prominent effects in G allele carriers. Regarding leptin receptor SNP, there were no statistically significant differences in BMI values between the genotype groups at baseline or after physical training. Our results suggest that physical training-induced alterations in body composition and plasma leptin may be influenced by a genetic variation of leptin promoter but not of leptin receptor.