Critical visceral adipose tissue thresholds aassociated with type 2 diabetes mellitus in chinese population

Objective: To compare intervertebral location L2-L3 with L4-L5 as landmarks for measuring abdominal fat distribution and to determine critical levels of visceral adipose tissue (VAT) at those planes, exceeding which may lead to the development of type 2 diabetes. Methods: Abdominal fat distribution was measured using computed tomography (CT) in 29 diabetics (19 male, 10 female) and 30 non-diabetics (18 male, 12 female). CT images obtained at two intervertebral locations L2-L3 and L4-L5 were used to measure the areas of total fat, VAT and subcutaneous adipose tissue (SCAT) using slice thickness of 5mm and an attenuation range from -190 to -30 Hounsfield units (HU). Data were analyzed using logistic regression and Receiver-operating characteristic (ROC) analysis. Results: At L2-L3, diabetes and obesity were correctly classified at 91.53% and 83.05% respectively, while at L4-L5, the same were correctly classified at 84.75% and 88.14% respectively. VAT compared to SCAT, had significantly higher correctly classified percent values for predicting diabetes in both measurement sites. At L2-L3, VAT≥177.29cm2 or VAT≥51.52% of the total fat area had the highest correctly classified value for predicting diabetes in men, while VAT≥132.27cm2 or VAT≥45.7% of the total fat area had the highest correctly classified value for predicting diabetes in women. At L4-L5, VAT≥130.82cm2 or VAT≥45.54% of the total fat area had the highest correctly classified value for predicting diabetes in men, while VAT≥118.56cm2 or VAT≥32.24% of the total fat area had the highest correctly classified value for predicting diabetes in women. Conclusion: L2-L3 plane is a better landmark for measuring abdominal fat distribution for predicting diabetes, while abdominal fat distribution measured at L4-L5 has better association with obesity. Regardless of the measurement site, VAT compared to SCAT, has significantly stronger association with diabetes.