TNF-αG-308A polymorphism is associated with insulin resistance: a meta-analysis

Area of Science:

• Genetics
• Metabolic Disorders
• Immunology

Background:

• Tumor necrosis factor-α (TNF-α) promoter polymorphisms are investigated for their role in obesity and insulin resistance.
• Previous studies on the TNF-α G-308A polymorphism and metabolic health have yielded conflicting results.
• A comprehensive meta-analysis is needed to clarify the association.

Purpose of the Study:

• To evaluate the association between the TNF-α G-308A polymorphism and obesity.
• To assess the relationship between the TNF-α G-308A polymorphism and insulin resistance markers, including insulin levels and HOMA-IR.
• To synthesize evidence from existing studies through meta-analysis.

Main Methods:

• A meta-analysis was conducted using data from 17 studies.
• Studies were identified through searches of electronic databases, including MEDLINE and EMBASE.
• Statistical analyses were performed to assess the effect of the TNF-α G-308A polymorphism on body mass index (BMI), obesity risk, insulin levels, and HOMA-IR.

Main Results:

• No significant association was found between the TNF-α G-308A polymorphism and BMI or obesity risk.
• The G-308A variant showed a significant association with increased insulin levels overall and in the obese subgroup.
• While no overall association with HOMA-IR was observed, subgroup analysis revealed a significant link between the G-308A polymorphism and increased HOMA-IR in Caucasians.

Conclusions:

• The TNF-α G-308A polymorphism significantly influences insulin resistance, evidenced by elevated insulin levels and, in Caucasians, increased HOMA-IR.
• The G-308A variant is unlikely to be a major genetic contributor to obesity.
• Further research may elucidate the precise mechanisms linking TNF-α G-308A to insulin resistance.