Worldwide, there has been an increase in the incidence of metabolic syndrome. The search for genetic markers contributing to this increase is ongoing. The leptin receptor has recently received attention. One of the polymorphisms (Gln223Arg), is possibly associated with the development of obesity and insulin resistance. However, the results of studies on this polymorphism remain equivocal. Gln223Arg polymorphism has not been studied previously in the Kyrgyzs. Thus, we aimed to investigate the possible association of the Gln223Arg polymorphism of the leptin receptor gene with metabolic syndrome components in the Kyrgyz population.

Material and methods:
237 Kyrgyz subjects, aged 35-70 years were studied. For the analysis anthropometric data, glucose, insulin, lipid spectrum, leptin were obtained. The genotype of the Gln223Arg leptin polymorphism was evaluated using the TaqMan PCR in real time.

The distribution of genotypes was as follows: Gln223Gln 46.4%, Gln223Arg 40.1%, Arg223Arg 13.5%. The study failed to obtain an association with abdominal obesity, arterial hypertension, hypertriglyceridemia and low-density cholesterol levels. The relationship of Gln223Arg and Arg223Arg genotypes with insulin resistance (p <0.03) was found. Gln223Arg polymorphism was associated with higher level of glycemia (5.54 vs. 5.39 mmol/l, p<0.05) and insulinemia (8.3 vs. 7.1 μIU/ml, p<0.05). Correlation analysis showed that carriers of the Arg 223 allele demonstrate a higher risk of insulin resistance (odds ratio [OR] 1.83 (95%CI: 1.03- 3.24); p<0.03) than carriers of the Gln 223 allele.

Gln223Arg polymorphism of the leptin receptor gene may be a marker of predisposition to insulin resistance in Kyrgyzs. Further studies are necessary to confirm these results in populations from other regions.