Which adiposity index is best? Comparison of five indicators and their ability to identify type 2 diabetes risk in a...

We compared ability of five adiposity indicators [body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), waist-by-height^0.5 (WHT.5R), and a body shape index (ABSI)] to identify current diabetes and their prospective associations with diabetes.

Baseline data were from 7,979 participants of UK Whitehall II study, of whom 7,488 diabetes-free participants were followed-up (median = 16.0 years) for incident diabetes (n = 940). According to five indices' cut-points, participants were separately classified into low-value groups and high-value groups. We cross-sectionally investigated ability of the indicators to identify existing diabetes by receiver operating characteristic curve analysis, and explored prospective associations between elevated indices and diabetes using Cox regression analysis.

Waist-based indicators were superior to BMI in identifying diabetes. High WHtR (≥0.5) demonstrated the highest multivariable-adjusted HR [2.64 (95 % CI 2.29, 3.03)]. Across all indicators, associations between elevated indicators and diabetes were stronger in younger participants. In combined analyses, "low BMI but high WHtR" had higher risk for diabetes [2.20 (95 % CI 1.65, 2.95)] than "high BMI but low WHtR" [1.34 (95 % CI 1.05, 1.70)].

Waist-based indicators are more strongly associated with diabetes than BMI. WHtR, an easy-to-calculate, waist-based index with a sex- and race-independent cut-point, may be useful for diabetes prevention.