Predictors of incident diabetes mellitus in Basrah, Iraq

New-onset diabetes was associated with a 90% increase in risk of all-cause mortality and a 120% increase in risk of cardiovascular mortality compared with study participants without diabetes. The aim of this study was to study prospectively the predictors of incident diabetes mellitus in Basrah, Iraq, with special emphasis on predictive performance of the four anthropometric variables of obesity, namely body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHpR) or waist-to-height ratio (WHtR).

A total of 13,730 subjects (7,101 males and 6,629 females) diabetes-free at baseline were followed for a mean of 5 years (January 2001 to end of December 2006).

There were 935 (6.80%) cases of incident diabetes (513 males and 422 females). All anthropometric indices (BMI, WC, WHpR, WHtR) were higher among those with incident diabetes (p < 0.001). In both sexes, WHpR has the strongest associations with incident diabetes that was gender-insensitive (AUC = 0.74 in males and 0.72 in females) followed by WC and then BMI which has the weakest association with incident diabetes. On multivariable logistic regression, only hypertension (OR 1.66; 95% CI 1.41-1.96; p < 0.001) was associated with incident diabetes. All anthropometric indices were significantly associated with incident diabetes except WHtR. There was no association between incident diabetes and gender, age, stroke, and ischemic heart disease.

In both sexes, WHpR has the strongest associations with incident diabetes, followed by WC then BMI which has the weakest association with incident diabetes, while WHtR has no association. Hypertension is the only non-anthropometric variable associated with incident diabetes.