[Prevalence of metabolic syndrome of children and adolescent students in Chinese six cities].

OBJECTIVE: To investigate the prevalence of obesity and metabolic syndrome in Chinese children and adolescents and to evaluate clinical applications of two definitions of metabolic syndrome in children and adolescents developed by The Society of Pediatrics, Chinese Medical Association in 2012 (MS-CHN2012) and by International Diabetes Federation in 2007 (MS-IDF2007), respectively.

METHOD: Totally 22 071 children (11 638 were boys and 10 433 were girls) aged 7 to 16 years from 6 representative geographical areas, including Beijing, Tianjin, Hangzhou, Shanghai, Chongqing and Nanning, were surveyed in a random cluster sample in Chinese. Anthropometric parameters and blood pressure were determined. Fasting blood glucose, fasting blood triglyceride, total cholesterol, and high-density lipoprotein cholesterol (HDL-C) levels were measured. Then non-high-density lipoprotein cholesterol (non-HDL-C) levels were calculated. The diagnostic concordance of the two definitions for metabolic syndrome (MS-CHN2012 and MS-IDF2007) and its individual components were estimated.

RESULT: (1) The prevalence of overweight and obesity was 19.9% in 7-16-year-old teenagers and the prevalence of obesity was 8.9%. The prevalence of obesity in boys was higher than in girls (10.9% vs. 6.6%, P < 0.001). (2) The prevalence of obesity in Northern region (Beijing, Tianjin), Midwest region (Chongqing and Nanning) and Eastern region (Hangzhou, Shanghai) were significantly different (χ(2) = 1.007×10(3), P < 0.001), the prevalence of obesity in Northern region was the highest (16.9%), in Midwest was 5.9% and in the Eastern region was the lowest (4.9%). The prevalence of obesity in boys was higher than in girls (10.9% vs. 6.6%, P < 0.001). (3) The prevalence of MS diagnosed by MS-CHN2012 and MS-IDF2007 in 7-16-year-old teenagers were 2.4% and 1.4%, respectively, and in obese subjects were 28.8% and 16.8%, respectively. The prevalence of MS diagnosed by MS-CHN2012 was higher than that diagnosed by MS-IDF2007 (P < 0.001). (4) The concordance between the two definitions for diagnosing metabolic syndrome was good (kappa = 0.711); as for detecting the individual components, the Kappa concordance index was 1.000, 0.818, 0.713, 0.686 for hyperglycemia, cholesterol abnormality, hypertriglyceridemia and hypertension, respectively.

CONCLUSION: (1) The prevalence of overweight and obesity was 19.9% in 7-16-year-old teenagers and the prevalence of obesity was 8.9%, which was higher in boys than in girls. The obesity of children had uneven geographical distribution and the Northern region was higher than the other. (2) The concordance between MS-CHN2012 and MS-IDF2007 definitions for diagnosing metabolic syndrome in Chinese children and adolescents was good. Compared with MS-IDF2007 definition, MS-CHN2012 definition was more effective to detect high risk of MS in children and adolescents and to reduce the risk of the occurrence of MS in adulthood.