Tumour necrosis factor-a 308G/A polymorphism is associated with insulin secretory defects in Bangladeshi prediabetic/diabetic subjects

Abstract

Objectives: Tumour necrosis factor (TNF)-a, an adipocytokine, is closely linked to impaired glucose tolerance (IGT) andinsulin resistance (IR) in type 2diabetes(T2D)subjects. The relationship between the polymorphisms in the TNF-a gene and IR in Bangladeshi prediabetes and T2D subjects has not yet been fully identified. This study aims to reveal the association betweenTNF-agene polymorphism andIR in hyperglycaemic patients of Bangladeshi origin. Methods: In our study, 106 IGT, 100 T2D, and 109 healthy subjects of Bangladeshi origin were recruited to identify the impact ofTNF-agenepolymorphismat position 308with a G>A transition using PCR and subsequent restriction fragment length polymorphism (RFLP). Results: The 308G>A TNF-a genotype frequency distributionwithin the control,IGT, andT2Dgroups showed a significant association (c2 ¼ 21.077; P ¼ 0.001), although allele frequency distribution within the groups showed a statistically non-significant difference (c2 ¼ 1.696; P ¼ 0.091). b-cell functional deficiency (HOMA-B%) was observedtobesignificantly(P¼0.034) lower insubjectswith a variant genotype. In addition, our results indicate that the study subjects’ body mass index (BMI) and residence status werepositivelycorrelated(P 0.05)with 308G>ATNF-a gene polymorphism. Conclusions: Therefore, it can be concluded that 308G>A TNF-agenepolymorphismmayhaveacausative relationship with lower insulin secretory capacity and higher BMI in Bangladeshi IGT and T2D populations, while the urban population’s lifestyle might be associated with this polymorphism.