The Arg16Gly polymorphism of human β2-adrenoreceptor is associated with type 2 diabetes in Taiwanese people

Abstract

Objective The significance of the association of amino terminal polymorphisms in β2‐adrenoreceptor (ADRB2) with obesity and type 2 diabetes is controversial and differs among ethnic groups. In this study, the association of ADRB2 with risk and age of onset of type 2 diabetes has been examined in a Taiwanese population. design The study design is a case–control study to investigate the impact of the two amino acid polymorphisms in ADRB2. patients and measurements This study includes 130 patients with type 2 diabetes [female : male = 1 : 1, age: 52·4 ± 10·0 years; body mass index (BMI): 24·2 ± 2·9 kg/m²; mean ± SD] and 130 controlled subjects matched for gender, age and BMI with normal glucose tolerance (female : male = 1 : 1, age: 51·7 ± 10·6 years; BMI: 23·9 ± 2·7 kg/m²). The Arg16Gly and Gln27Glu polymorphisms of ADRB2 were determined by polymerase chain reaction‐restriction fragment length polymorphism (PCR–RFLP) assays. The genotypic and allelic frequencies between two groups were compared and the relationship between the genotypes and clinical phenotypes was examined. results A difference in genotypic frequency in the Arg16Gly polymorphism was noted between groups in this gender‐, age‐ and BMI‐matched case–control study (P = 0·039). Multivariate regression analysis revealed that the Arg16Gly polymorphism was the only independent factor for development of type 2 diabetes (P = 0·021). In addition, we utilized the log‐rank test to compare the differences in age of onset between wild‐type and nonwild‐type polymorphisms. The Arg16Gly polymorphism was independently associated with age of onset in type 2 diabetes (P = 0·017). There was no difference in the Gln27Glu polymorphism between diabetic and control groups in this study. conclusions In a Taiwanese population, homozygosity of Arg16 in the ADRB2 gene was associated with a higher frequency (odds ratio 1·87, 95% confidence interval 1·34–2·40) for development of type 2 diabetes. Moreover, this polymorphism was also associated with an earlier onset of type 2 diabetes. However, the Glu27Gln polymorphism had no impact on either BMI or type 2 diabetes in a Taiwanese population.