Sagittal abdominal diameter is more predictive of cardiovascular risk than abdominal fat compartments in severe obesity

Objective: To compare the predictive role of abdominal fat distribution by computed tomography (CT) with that of total abdominal fat by sagittal abdominal diameter (SAD) on cardiovascular risk in severe obesity. Design: A cross-sectional, clinical study. Subjects: 64 males and 64 females, aged 42±15 years (mean±s.d.; range 18-75 years), BMI (kg/m²) 41.7±5.3 (30.2-57.6). Measurements: Blood glucose, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides (TGLs), insulin (IRI), insulin resistance (HOMA-IR), slice areas (cm²) of total (tSAT), superficial (sSAT) and deep subcutaneous adipose tissue (dSAT), visceral adipose tissue (VAT) and SAD (mm) by CT. Results: The sSAT depot was negatively associated with blood glucose, HOMA-IR, LDL cholesterol and TGLs, whereas dSAT was negatively associated with HDL cholesterol. VAT was associated with blood glucose and HOMA-IR, whereas SAD was associated with all variables evaluated. In males, VAT was associated with blood glucose (r²=0.12, P<0.01), SAD was associated with blood glucose (r²=0.67, P<0.01), IRI (r²=0.65, P<0.05), and HOMA-IR (r²=0.67, P<0.01). In females, sSAT was negatively associated with blood glucose (r²=0.63, P<0.05), whereas VAT was associated positively with blood glucose (r²=0.21, P< 0.001), total cholesterol (r²=0.16, P<0.01), LDL cholesterol (r ²=0.20, P<0.001) and TGLs (r²=0.12, P<0.01). SAD was associated positively with IRI (r²=0.52, P<0.05), HOMA-IR (r ²=0.53, P<0.05), total cholesterol (r²=0.52, P<0.05), LDL cholesterol (r²=0.54, P<0.01), TGLs (r ²=0.52, P<0.05) and negatively to HDL cholesterol (r ²=0.51, P<0.001). Conclusion: When compared with CT-based measures of abdominal fat compartments, SAD is a more predictive indicator of cardiovascular risk in severe obesity.