Central obesity predicts the worsening of glycemia in southern Chinese

Aims: The association between obesity and type 2 diabetes has been found to be consistent across different ethnic populations. Our aim was to study the contribution of obesity to the development of type 2 diabetes in a non-obese Chinese population with a high prevalence of diabetes (9.8% in 1995-1996). Methods: Six-hundred and forty-four non-diabetic subjects were recruited from the Hong Kong Cardiovascular Risk Factor Prevalence Study (1995-1996). This was a community-based population study which involved the use of a 75 g oral glucose tolerance test and 1985 World Health Organization diagnostic criteria. Their glycemic status was reassessed at 2 y. Results: In subjects with impaired glucose tolerance (n=322), the annual progression rate to diabetes (4.8%; 95% CI 2.5-7.1%), was 8-fold that in control subjects (0.6%; 95% CI 0.0-1.4%; P<0.001). Baseline waist-hip ratio (WHR; OR per unit increase = 1.05; 95% CI 1.02-1.07, P=0.0003) and post-load 2 h plasma glucose (OR per unit increase = 2.02; 95% CI 1.76-2.34, P<0.0001) were significantly associated with glycemic status at 2 y in stepwise polytomous logistic regression analysis. Subjects with high baseline waist circumference or WHR (greater than or equal to median) were more likely to have worsening of glucose tolerance at 2y than those with low waist circumference (<median; conversion to diabetes, OR 3.8, P=0.001) or WHR (<median; conversion to diabetes, OR 2.8, P=0.019). Conclusion: Abdominal obesity, readily assessed by the measurement of WHR or waist circumference, was for the first time shown prospectively to be independently associated with the deterioration of glucose tolerance in a Chinese population.