Type 2 diabetes mellitus (T2DM) subjects of Bangladeshi origin with fast N-acetyltransferase 2 (NAT2) acetylator phenotype show lower insulin sensitivity than slow acetylator phenotype

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

Objectives

Tumour necrosis factor (TNF)-α, an adipocytokine, is closely linked to impaired glucose tolerance (IGT) and insulin resistance (IR) in type 2 diabetes (T2D) subjects. The relationship between the polymorphisms in the TNF-α gene and IR in Bangladeshi prediabetes and T2D subjects has not yet been fully identified. This study aims to reveal the association between TNF-α gene polymorphism and IR 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 of TNF-α gene polymorphism at position −308 with a G>A transition using PCR and subsequent restriction fragment length polymorphism (RFLP).

Results

The −308G>A TNF-α genotype frequency distribution within the control, IGT, and T2D groups showed a significant association (χ² = 21.077; P = 0.001), although allele frequency distribution within the groups showed a statistically non-significant difference (χ² = 1.696; P = 0.091). β-cell functional deficiency (HOMA-B%) was observed to be significantly (P = 0.034) lower in subjects with a variant genotype. In addition, our results indicate that the study subjects’ body mass index (BMI) and residence status were positively correlated (P ≤ 0.05) with −308G>A TNF-α gene polymorphism.

Conclusions

Therefore, it can be concluded that −308G>A TNF-α gene polymorphism may have a causative 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.