Overweight of Korean Male Workers and Genetic Polymorphism of Insulin Receptor Substrate 1 (IRS1) Gene

We have examined the hypothesis that the Gly972Arg variant of the insulin receptor substrate 1 (IRS1) gene is associated with the components contributing to overweight (obesity) and metabolic syndrome. We describe IRS1 genotype frequencies in 274 Korean men. The frequencies of Gly972Gly (G/G) and Gly972Arg (G/A variant) of the IRS1 gene were 88.3% and 11.7%, respectively, and the differences in frequencies between the overweight (BMI greater-than or equal to 25 kg/㎡) group and non-overweight (BMI less than 25 kg/㎡) group were statistically significant. The subjects with G/A variant of IRS1 gene in non-overweight had significantly higher level of visceral fat thickness and adiponectin/leptin ratio than those with G/G alleles. In overweight group, the subjects with G/A variant of IRS1 gene also showed significantly higher level of insulin than those with G/G alleles. These results suggest that the IRS1 genetic polymorphism is involved in the occurrence of overweight, as well as metabolic syndrome.