These data are from the Nurses’ Health Study (Carey VJ et al, 1997), an observational study that followed a cohort of 43,581 women between 1986 and 1994 in the USA. The analysis presented here was designed to define the association between waist circumference and the risk of developing type 2 diabetes.

The risk of developing type 2 diabetes increased linearly with an increasing waist circumference. The relative risk for women at the 90th percentile of waist circumference (equivalent to a waist measurement of 92 cm [36 in]) was 5.1 (95% CI 2.9-8.9) compared with women at the 10th percentile (waist measurement of 67 cm [26.2 in]). High waist circumference is a powerful predictor of an increased risk of developing type 2 diabetes (Wang Y et al, 2005).