Frequency of Gly972Arg polymorphism of the insulin receptor substrate 1 (IRS-1) gene in essential hypertension

Abstract

Introduction Difficulties in studies on the genetic background of arterial hypertension are compounded when hypertension is part of the complex polymetabolic syndrome together with obesity, type 2 diabetes, and dyslipidemia. Atherogenicity in this case is fuelled by insulin resistance present in some 50% of patients with hypertension. The present study was undertaken to determine the frequency of Gly972Arg polymorphism of the cytoplasmic insulin receptor substrate-1 (IRS-1) gene in a well-defined, homogenous group of patients with essential hypertension.
Material and methods The study group comprised 115 nonobese (BMI 24.72 ± 1.93 kg/m²) patients, aged 27.48 ± 5.15 years, with essential and uncomplicated arterial hypertension, while 46 healthy persons aged 28.0 ± 4.39 years (BMI 22.6 ± 2.16 kg/m²) formed the control group. There were no cases of diabetes or dyslipidemia in the groups. A single sample of 5 ml venous blood was drawn and genomic DNA was isolated for genotyping with the polymerase chain reaction as described by Yamade et al.
Results The GA genotype was disclosed in 16 (13.9%) patients and in just 2 controls (4.3%), one of them (2.2%) being AA homozygote. The χ² test did not disclose significant differences between both groups in the distribution of genotypes.
Conclusion The distribution of Gly972Arg polymorphism of the IRS-1 gene appears to be similar in hypertensives and normotensives suggesting that this polymorphism is not directly involved in the pathogenesis of arterial hypertension.