Metabolic syndrome in overweight and obese Japanese children.

OBJECTIVE: To determine the prevalence of and sex differences related to the metabolic syndrome among obese and overweight elementary school children. RESEARCH METHODS AND PROCEDURES: Subjects were 471 overweight or obese Japanese children. Children meeting at least three of the following five criteria qualified as having the metabolic syndrome: abdominal obesity, elevated blood pressure, low high-density lipoprotein-cholesterol levels, high triglyceride levels, and high fasting glucose levels. Fasting insulin levels were also examined. RESULTS: Japanese obese children were found to have a significantly lower prevalence (17.7%) of the metabolic syndrome than U.S. obese adolescents (28.7%, p = 0.0014). However, Japanese overweight children had a similar incidence (8.7%) of the metabolic syndrome compared with U.S. overweight adolescents (6.8%). Hyperinsulinemia in girls and abdominal obesity in boys are characteristic features of individual metabolic syndrome factors in Japanese children. DISCUSSION: The prevalence of the metabolic syndrome is not lower in preteen Japanese overweight children than in U.S. overweight adolescents, although it is significantly lower in Japanese obese preteen children than in U.S. obese adolescents. Primary and secondary interventions are needed for overweight preteen children in Japan.