Effect of Recovery From Obesity on Cardiovascular Risk Factors Among Japanese Schoolchildren: The Iwata Population-Based Follow-Up Study

BACKGROUND: The effect of recovery from obesity on cardiovascular risk factors is not well understood in Japanese children. METHODS: We analyzed follow-up data from the Iwata city population-based study of schoolchildren in Japan. The Iwata Board of Education conducted health screenings of children aged 10 and 14 years. A total of 914 children aged 10 years (451 boys and 463 girls, 87.1% of all children in the city in 1997) were followed until 14 years of age and classified by pattern of obesity as Normal, Recovered, Worsened, or Persistent. RESULTS: Of the 914 children, 111 (12%) were obese at 10 years of age. Of those children, 44 (40%) were no longer obese at 14 years (ie, Recovered). At follow-up, Recovered boys had the greatest decrease in non-HDL cholesterol (mean ± SE, −21.3 ± 3.6 mg/dL) among the 4 groups, and Recovered girls had a significantly lower level of non-HDL cholesterol (Recovered, 107.1 ± 5.4 mg/dL vs. Persistent, 126.1 ± 4.5 mg/dL). The Recovered boys also had a significantly higher level of HDL cholesterol at age 14 (Recovered, 67.2 ± 2.7 mg/dL vs. Persistent, 53.3 ± 2.1 mg/dL). In the Recovered group, 68% of children who were dyslipidemic at baseline had normal cholesterol levels at age 14. The recovery rate from dyslipidemia was significantly higher in the Recovered group (cumulative incidence rate ratio, 2.5; 95% confidence interval, 1.4–4.7) as compared with the Persistent group. CONCLUSIONS: Dyslipidemia was reversed in children who recovered from obesity. Our findings suggest that reducing obesity is beneficial to the health of Japanese schoolchildren.