Associations of -308G/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 -308G/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 -308G/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 -308G/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 -308G/A polymorphism of TNF-α gene is not associated with differences in the serum levels of TNF-α in Asian Indians.