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 (> or =median) were more likely to have worsening of glucose tolerance at 2 y 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.