No Association of Leptin Receptor Gene Gln223Arg Polymorphism with Capillary Glucose Levels: A Preliminary Population Base Cross-Sectional Study

The leptin receptor gene has been reported to associate with insulin and glucose metabolism and adiposity in different study settings and various populations. Therefore, the aim of the study was to investigate the associations of the leptin receptor gene Gln223Arg polymorphism (LEPR Gln223Arg) with high capillary glucose levels. Cross-sectional study with probabilistic sample was carried out in individuals aged ≥18 years in an urban area of Montes Claros, MG, Brazil. The capillary glucose was considered high when ≥140？mg/dL. The genotypes of LEPR Gln223Arg distribution were as the following: 10.43%？GG ( ), 46.81%？AG ( ), and 42.77%？AA ( ), and there were no prevalence differences between genders, ( ). Multivariate-adjusted models showed that there is no association between the polymorphism LEPR Gln223Arg and capillary high levels of glucose even when adjusted for age, sex, smoking, schooling, and parental history of obesity. In conclusion, no association between the polymorphism LEPR Gln223Arg and elevated blood glucose levels was detected. 1. Introduction The leptin hormone is an adipocyte-specific ob gene product that regulates the energy balance and multifaceted biological actions and performs its central effects through several neuroendocrine systems [1]. There are multiple lines of evidence with regard to the association between variants of the gene encoding the leptin receptor and the metabolism of the hormone, a certain degree affecting the biological function and serum leptin [2–5]. In this sense, specifically leptin receptor gene Gln223Arg polymorphism (LEPR Gln223Arg) has been mentioned as one of the factors of genetic predisposition to overweight and other cardiometabolic events [4, 6–10] and as suggesting that obesity that genetic variation plays a leptin-resistance [11]. Since the LEPR Gln223Arg has a functional importance for obesity, it could play a significant role in type 2 diabetes mellitus and pathophysiology of human obesity [12]. Furthermore, they may share a common genetic background; that is, the risk alleles for obesity may also be involved in the increased risk of developing type 2 diabetes [13, 14]. Studies with the leptin receptor, it will be important to clarify the functionality of different genetic variants, since several studies have found significant associations linking them to several traits of obesity, diabetes or the metabolic syndrome [10, 13]. For our knowledge, no data are yet available in Brazil on the association of the LEPR Gln223Arg genotypes and capillary glucose levels as a proxy of impaired metabolism