Objective To investigate the association between adiponectin and metabolic syndrome (MetS) and related diseases in older adults from major cities of China.Methods A total of 2 049 adults at the age of 60-96 years from 18 major cities of China were enrolled in the study.Plasma adiponectin and insulin concentrations were measured.Insulin resistance was assessed by homeostasis model assessment of insulin resistance (HOMA-IR).The definitions proposed by International Diabetes Federation (IDF)and American Heart Association/National Heart,Lung,and Blood Institute (AHA/NLHBI)were used to identify MetS.Results The adiponectin concentration increased with the advance of age and was higher in women than in men.The sex specific adiponectin concentration was inversely correlated with body mass index(BMI),waist circumference,diastolic blood pressure,triglycerides,glucose and fasting blood insulin,and positively correlated with HDL-C(P<0.001).The adiponectin concentration decreased with increasing MetS components.Compared with the 4th sex-specific adiponectin quartile,the odds ratio(OR)for prevalent MetS-IDF and MetS-AHA/NLHBI in subjects of the 1st quartile group was 3.25(95% CI:2.24,4.71)and 3.21(95% CI:2.26,4.55),respectively.The association was independent of age,sex,life-style factors,medication,family history of chronic diseases,BMI,and HOMA-IR.The OR for MetS was much higher than those of MetS components and its related diseases.Conclusion Adiponectin is strongly associated with MetS independent of insulin resistance and obesity in older adults from major cities in China.The adiponectin concentration is a useful predictor for the risk of MetS. Objective To investigate the association between adiponectin and metabolic syndrome (MetS) and related diseases in older adults from major cities of China. Methods A total of 2 049 adults at the age of 60-96 years from 18 major cities of China were enrolled in the The definitions proposed by International Diabetes Federation (IDF) and American Heart Association / National Heart, Lung, and Blood Institute (AHA / NLHBI) were used to identify MetS. Results The adiponectin concentration increased with the advance of age and was higher in women than in men. Sex specific adiponectin concentration was inversely correlated with body mass index (BMI), waist circumference, diastolic blood pressure, triglycerides, glucose and fasting blood insulin, and correlated positively with HDL-C (P <0.001) .Adiponectin concentration decreased with increasing M etS components. Complied with the 4th sex-specific adiponectin quartile, the odds ratio (OR) for prevalent MetS-IDF and MetS-AHA / NLHBI in subjects of the 1st quartile group was 3.25 (95% CI: 2.24,4.71) and 3.21 (95% CI: 2.26,4.55), respectively. The association was independent of age, sex, life-style factors, medication, family history of chronic diseases, BMI, and HOMA-IR.The OR for MetS was much higher than those of MetS components and its related diseases. Confocal Adiponectin is strongly associated with MetS independent of insulin resistance and obesity in older adults from major cities in China. The adiponectin concentration is a useful predictor for the risk of MetS.