Associations of −308 G/A Polymorphism of Tumor Necrosis Factor (TNF) – α Gene and Serum TNF- α Levels with Measures of Obesity, Intra-Abdominal and Subcutaneous Abdominal Fat, Subclinical Inflammation and Insulin Resistance in Asian Indians in North India

Objectives: Obesity is associated with high levels proinflammatory cytokines like tumour necrosis factor alpha (TNF- α ), which may play an important role in the genesis of insulin resistance. We evaluated the relationship of −308 G/A polymorphism of TNF-α gene with obesity and insulin resistance in Asian Indians in north India. Methods: This cross-sectional study included 151 apparently healthy individuals (79 males, 72 females) 18–50 yrs of age from New Delhi, India. Body composition by dual-energy x-ray absorptiometry (DEXA) and abdominal fat by magnetic resonance imaging (MRI) were measured. Biochemical measurements included OGTT, lipids, fasting insulin, hs-CRP and TNF- α levels. We analysed −308 G/A polymorphism of TNF - α gene and studied its association with obesity and biochemical parameters. Results: At comparable BMI, abdominal obesity was more prevalent in females (50%) as compared to males (20%). The wild genotype ( GG ) was present in 78.8%, GA in 17.9%, and AA in 3.3% subjects. Measures of body composition, abdominal fat distribution, lipids, insulin, hs-CRP and TNF- α levels were not influenced by the presence of −308 G/A polymorphism. Serum TNF- α levels correlated significantly with fasting insulin in both genders. Conclusion: TNF- α levels correlate with fasting insulin but not with indicators of body composition in Asian Indians. The −308 G/A polymorphism of TNF-α gene is not associated with differences in the serum levels of TNF- α in Asian Indians.