1 Universidade do Estado do Rio de Janeiro - Uerj, Brazil; 2 Universidade Federal do Rio de Janeiro - UFRJ, Brazil; 3 Instituto Federal de Educação, Ciência e Tecnologia do Rio De Janeiro - IFRJ, Brazil
Leptin (LEP), a hormone secreted mainly from adipose tissue, action via leptin receptor (LEPR), is associated with regulation of energy balance. The inverse association between physical exercise (PE) and leptin serum levels was observed in subjects exposed to high amount of PE. Polymorphisms of the LEPR and the LEP genes have been tested for modulating physiological response to PE, but its role is still conflicting. Therefore, the aim of this study was to examine the influence of LEP and LEPR genotypes on body mass index (BMI), fat mass (FM), fat free mass (FFM) and serum levels of leptin on high physically trained Brazilian military (n=61; 21-23 years). Whole blood sample were taken after overnight fast at baseline and at the end of 48h of training to determine leptin serum levels and isolate DNA to identify LEP 19G>A (rs2167270) and LEPR 668 A>G (rs1137101) genotypes. Leptin serum levels were higher (p<0.05) at baseline (0.81 ± 0.66 ng/mL) than after training (0.39 ± 0.29 ng/ mL). FM was greater (p<0,05) in subjects homozygous for the LEP 19A allele (13.1 ± 6.6 Kg) than others (9.6 ± 4.0 Kg). The serum leptin at baseline in subjects carrying the LEPR 668 G allele were higher (0.98 ± 0.96 ng/mL) than in subjects homozygous for the A allele (0.69 ± 0.46 ng/mL), but none difference were observed aft physical training. Our results suggest that LEP variation influence body composition and that physical training-induced alterations on serum leptin and may be influenced by genetic variation of LEPR but not LEP. Financial support: FAPERJ and CNPq