Leptin and Leptin receptor polymorphisms, plasma Leptin levels and obesity in Tunisian volunteers

Adipose tissue is an important endocrine organ that secretes a number of adipokines, like Leptin (LEP). The aim this study was to investigate the prevalence of single nucleotide polymorphisms in LEP gene (LEP 3UTR A/C, -2548G/A) and LEPR (K109R and Q223R) and their association with Leptin level and obesity. We recruited 169 non-obese (body mass index [BMI]=24.51-3.69kg/m(2)) and 160 obese (BMI=36-4.78kg/m(2)) patients. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism, BMI was calculated, and Leptin level was measured by ELISA. Statistical analyses were performed by spss19.0. According to LEP 3UTR A/C polymorphism, AC and CC genotype carriers had higher Leptin levels than AA genotype carriers, respectively, 31[0.05-148.8] (P=.008) vs 41[0.05-111.6] (P=.003). The K109R polymorphism was associated with obesity (P=.025) and seems to significantly decrease the LEP levels (P<.001). Concerning LEP G2548A polymorphism, our results showed that the OR of obesity associated with 2548 AA/GG was 1.87[1.106-2.78] P=.028 vs 1.41[1.035-1.85] P=.045 for 223AA/GG polymorphism. In our haplotype analysis, one haplotype seems to be the more protective and one other seems to be the highest risk to obesity. LEP 3UTR A/C and LEPR K109R polymorphisms were associated with Leptin level and obesity.