Association of TNF-α promoter gene G-308A polymorphism with metabolic syndrome, insulin resistance, serum TNF-α and leptin levels in Indian adult women.

BACKGROUND: Tumour necrosis factor alpha is a multifunctional proinflammatory cytokine involved in the pathogenesis of metabolic syndrome, insulin resistance, and obesity. Aim of this study is to investigate in a North Indian female population the impact of the G-308A TNF-α variant on various components of the metabolic syndrome, Insulin Resistance, serum TNF-α and Leptin levels. METHODS: The G-308A TNF-α polymorphism has been studied in 269 females with metabolic syndrome (NCEP ATP III criteria) (age 31.91±6.05) and 272 healthy females without metabolic syndrome (age 30.96±7.01). The G-308A variant was detected by PCR amplification and Nco-1 digestion. RESULTS: Homozygous mutant genotype (AA) (p=<0.001: OR=3.24: 95% CI=2.15-4.89) and mutant allele (A) (p=<0.001: OR=3.04: 95% CI=2.08-4.43) of TNF-α was significantly less frequently observed in the control population as compared to study group. Furthermore, on dividing the subjects into two groups according to the absence (TNF-1 allele) or presence of the mutant A (TNF-2) allele, significant results were obtained in most of the metabolic risk factors. CONCLUSIONS: Our results suggest that the G-308A polymorphism of the TNF-α gene may be independently associated with hypertension, leptin level and hypercholesterolemia leading to metabolic syndrome independent of Insulin resistance and hyperglycemia.