Sagittal abdominal diameter and waist circumference are equally good as identifiers of cardiometabolic risk

Background Body mass index (BMI) and waist circumference (WC) are commonly used markers of cardiometabolic risk. However, sagittal abdominal diameter (SAD) has been proposed to be a better marker of intra-abdominal obesity compared to WC and might better associate with metabolic disturbances in high-risk populations. The objective of this study was to compare SAD, WC, and BMI as determinants of an adverse metabolic phenotype. Method Anthropometric and metabolic measures of 1516 overweight or obese individuals with features of the metabolic syndrome were included to examine differences between SAD, WC and BMI as measures of an adverse metabolic phenotype. Multiple linear regression and logistic regression models were used to investigate the association between SAD, WC, and BMI and markers of metabolic syndrome, insulin resistance, blood lipids, and low grade inflammation. Results Both SAD and WC correlated with BMI, but as BMI increased, SAD proportionately estimated higher abdominal adiposity compared to WC (slope = 0.0037 (0.0029; 0.0046), p<0.0001). We did not find major differences between SAD, WC and BMI in explained variance in models with the different markers of metabolic risk. Furthermore, we did not find differences between SAD and WC in the ability to identify individuals with metabolic syndrome according to the International Diabetes Federation (IDF) cut-offs, but a few differences from BMI were indicated but mostly before adjustments. Moreover, the differences between SAD and WC associations were not modified by sex or degree of adiposity, but identification of individuals with a metabolic phenotype was generally better in women. Conclusion These data indicate that SAD and WC are equally good indicators of an adverse metabolic phenotype. Thus, from a public health perspective choice of anthropometric measure may depend only on what is the most practical method in a given situation.