The metabolic syndrome and incident diabetes: assessment of four suggested definitions of the metabolic syndrome in a Chinese population with high post-prandial glucose.

AIMS: To assess the sensitivity and specificity of the four definitions of the metabolic syndrome for incident diabetes in both men and women. METHODS: The screening survey for type 2 diabetes was conducted in 1994. A follow-up study on 627 high-risk non-diabetic individuals at baseline was carried out in 1999 in Beijing area. 70 men and 76 women developed diabetes during the five-year follow-up. Sensitivity and specificity of four definitions of the metabolic syndrome based on the NCEP, WHO, EGIR and AACE recommendations were compared by McNemar's test. RESULTS: The metabolic syndrome based on all four definitions identified men at a 3.7-4.5-fold and women at a 1.6-2.8-fold risk of developing diabetes during 5-year follow-up. The AACE definition had the highest sensitivity for predicting diabetes (men: 0.61; women: 0.58) and lowest specificity (men: 0.71; women: 0.70). The WHO definition identified 53 % of male and 42 % female incident diabetes. The NCEP definition of adiposity as waist girth > 102 cm was the least sensitive, detecting only 27 % of incident diabetes in men; however, it was the most specific (0.91). The EGIR definition identified the lowest number of female cases (28 %) and fewer male cases (28 %) of incident diabetes, but was specific (women: 0.87; men: 0.91). CONCLUSIONS: Further studies on definition of the metabolic syndrome should focus on the potential ethnic differences in insulin resistance and anthropometric indicators for obesity.