Visceral & subcutaneous abdominal fat in relation to insulin resistance & metabolic syndrome in non-diabetic south Indians.

Background & objectives: The objective of the study was to determine whether visceral or subcutaneous component of abdominal fat was associated with insulin resistance and metabolic syndrome in non-diabetic Asian Indians. Method: This cross-sectional study had on 120 individuals with normal glucose tolerance (49 males and 71 females). A single slice CT scan at L4- L5 was done for measurement of visceral and subcutaneous abdominal fat. Metabolic syndrome was defined according to the South Asian Modified National Cholesterol Education Program Adult Treatment Panel III criteria (SAM-NCEP) criteria. Insulin Sensitivity Index (ISI-Matsuda) was used to assess insulin sensitivity/resistance. Results: Linear regression analysis revealed that visceral, but not subcutaneous fat was associated with serum triglycerides (R2=0.457, β= 0.34; P=0.006), HDL cholesterol (R2=0.430, β= -0.051; P=0.018) and ISI-Matsuda (R2=0.437, β= -0.05; P=0.039) after adjusting for age, gender and BMI. Visceral fat showed significant association with metabolic syndrome (OR: 1.013, 95% CI: 1.001- 1.025; P=0.041) even after adjusting for age, gender, body mass index and glycated haemoglobin whereas subcutaneous fat did not show such an association. Interpretation & conclusions: These results indicate that in non-diabetic Asian Indians, visceral, but not subcutaneous component of abdominal fat is associated with insulin resistance, cardiovascular risk factors and metabolic syndrome.