Background and aims: Carrying variants on the leptin receptor gene (LEPR) may have an impact on inflammatory and stress markers. Thus, the aim of the study was to analyze the role of the Lys109Arg LEPR gene polymorphism on inflammatory (leptin and IL-6) and stress (cortisol) markers in obese subjects who followed a hypocaloric diet designed to lose weight.
Methods: One hundred and seventy (80 females/90 males) Caucasian subjects (body mass index: 30.8 +/- 2.4 kg/m(2)), were genotyped for the Lys109Arg polymorphism by a PCR/RFLP procedure. Anthropometric measurements were assessed and blood samples were drawn in all the volunteers before and after an 8-week energy-restricted diet (-30% E). Plasma levels of leptin as well as interleukin-6 (IL-6) as proinflammatory markers and circulating cortisol concentrations as a stress hormone were measured.
Results: Weight loss (-6.1 +/- 2.7%; p <0.001) induced significant changes in anthropometric and biochemical determinations. The AA genotype group showed a higher fat mass loss as well as greater total cholesterol decrease compared with the minor allele carriers. Moreover, the G allele carriers were associated with a higher basal risk of inflammation (OR = 2.5; p = 0.042) and stress (OR = 3.3; p = 0.011), which were reduced after weight lowering (p >0.05).
Conclusions: The Arg allele carriers of the Lys109Arg LEPR gene polymorphism were associated with an increased proinflammatory state and stress condition at baseline. These obesity-related markers were importantly decreased after following a hypocaloric diet.