Associations between single-nucleotide polymorphisms of the adiponectin gene, serum adiponectin levels and increased risk of type 2 diabetes mellitus in Iranian obese individuals

Abstract

Introduction: Adiponectin is an adipose tissue-secreted hormone with important metabolic effects. There have been inconsistent reports about SNPs of the adiponectin gene and risk of type 2 diabetes (T2DM). The aim of this study was to investigate any association between SNPs (+45 T/G and +276 G/T) of the adiponectin gene with serum adiponectin levels, metabolic factors and risk of T2DM in obese individuals. Design and methods: Genotyping for two common SNPs of adiponectin gene was performed in 50 unrelated obese type 2 diabetic patients and 52 obese non-diabetic control subjects by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Lipid profile was measured by enzymatic methods. Serum adiponectin, insulin, leptin and glucose levels were measured by immunoassay, and glucose oxidase methods, respectively. Results and conclusion: It was observed that obesity and T2DM are associated with low serum adiponectin levels. The G allele and TG/GG genotype of SNP 45 occurred more frequently than the T allele and TT genotype in T2DM patients compare to the controls (p<0.05). Subjects with the G/G + TG genotype of SNP 45 were at increased risk for T2DM [Odds Ratio (OR) 2.574; 95% Confidence Interval (CI) 1.051–6.302; p=0.036] compared with those T/T genotype. There was no statistically significant difference in allele and genotype frequencies of SNP 276 comparing control group with T2DM group. Thus, our results demonstrated that, adiponectin SNP 45T/G, rather than SNP 276G/T, is more associated with risk of T2DM in obese individuals.

Keywords::

• Adiponectin
• SNP
• PCR-RFLP
• T2DM
• obesity

Acknowledgements

This project was supported by the Endocrine Research Center, Tehran University of Medical Sciences, and nutritional research center, Tabriz University of Medical Sciences, grant number E222. The authors are grateful to the people located radio pharmacy lab in drug applied research center, Tabriz University of Medical Sciences.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.