OBJECTIVETo compare the characteristics of over weight and obesity subjects defined by three criteria: World Health Organization (WHO) in 1999, the National Cholesterol Education Program Adult Treatment Panel Nll (NCEP-ATP II ) in 2001, and the International Diabetes Federation (IDF) in 2005.

METHODSMedical history collection, physical examination, oral glucose tolerance test ( OGTT) , and frequently sampled intravenous glucose tolerance test (FSIGTT) were performed in 371 subjects with body mass index (BMI)> or =23 kg/m(2). Fasting blood samples were taken to test lipid profiles, urea acid level and so on. Data was analyzed including comparison and relationship statistics.

RESULTSData from FSIGTT showed that insulin resistance existed in all over weight and obesity subjects. The relationship between waist and sensitivity index (SI) was superior than that between BMI and SI ( r = - 0. 198 and r = - 0. 194, P < 0. 001). Totally 107 subjects (28. 8%) did not meet any definitions, 187 (50. 4%) met ATP definition, 98 (26. 4%) met WHO definition, and 234 (63. 1% ) met IDF definition. ATP and IDF definitions had the highest coincidence rate (70. 3% ) , and subjects in these two groups almost had basically the same manifestations. The age of onset in WHO group was higher than those in other two groups. Meanwhile, subjects in the WHO group was characterized by lower BMI, higher hyperlipidemia, and significantly increased fasting and postprandial blood glucose level. The MS component scores were positively correlated with age, BMI, waist, and waist-to-hip ratio (WHR) , and were negatively correlated with SI. However, no correlation was found between MS component scores and gender, fat% , or acute insulin response to glucose index.

CONCLUSIONSSome of over weight and obesity subjects only have insulin resistance and have no metabolism syndrome. The group defined by IDF criteria of the metabolic syndrome (MS) has the highest incidence rate. Limited by the requirements of insulin resistance evaluation, the definition proposed by WHO is somewhat unfeasible for practices. ATP definition may be replaced by IDF definition, because the populations defined by ATP definition is covered by the latter. Meanwhile, the abnormalities of fat mass distribution in the body ( i. e. , central obesity) , rather than its contents, may exacerbate the occurrence of MS, as well as the development of insulin resistance.