Association Between the Gln223Arg Polymorphism of the Leptin Receptor and Metabolic Syndrome in Free-Living Community Elderly

Abstract

Metabolic syndrome is a cluster of cardiovascular risk factors. Aging and gene-environmental interactions are involved in the pathophysiology of metabolic syndrome. The LEPR gene Gln223Arg polymorphism has been associated with energy metabolism and body weight. The association of the Gln223Arg polymorphism with metabolic syndrome was evaluated in a case-control study with elderly subjects (> or = 60 years old). The case-control groups were: (1) healthy group (HG), individuals without any cardio-metabolic diseases (CMD) or previous cardiovascular events (n = 64); (2) metabolic disorder group (MD), subjects with at least one metabolic disorder (hypertension, obesity, dyslipidemia, and impaired glucose tolerance, n = 306); and (3) metabolic syndrome group (MS) (n = 98). The Gln223Arg polymorphism of the LEPR gene was determined by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) using Msp I endonuclease enzyme restriction. The mean age of the HG subjects was 70.12 +/- 7.7, and the MD and MS subjects were 69.7 +/- 6.4 and 69.68 +/- 5.0 years old, respectively. The MS group showed higher body mass index (BMI), waist circumference, systolic and diastolic blood pressure, glucose, cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C) levels than did the HG individuals. The analysis showed differences in genotype frequencies: reduction in the Gln/Gln genotype and an excess of the Arg/Arg genotype in MD (chi(2) = 7.886, P = 0.019) and MS (chi(2) = 14.941, P = 0.001) when compared to the HG group. This study provides evidence for a role of the LEPR gene Gln223Arg polymorphism in predisposition to metabolic syndrome in the elderly.