Risk factors of obesity in preschool children in an urban area in China.

To assess risk factors of childhood obesity, we carried out a case-control study in ten kindergartens in Changsha, the capital city in the Chinese province of Hunan, between July 1 and December 31, 2007. Height and weight measurements were obtained from annual physical examinations for children attending these kindergartens. Obesity was defined according to the International Obesity Task Force cutoff for body mass index (BMI). For each obese child, one child with normal BMI, matched by kindergarten class, sex, age (within 3 months), and height (within 3 cm) were chosen as controls. The parents of the study subjects were asked to complete a questionnaire about their children, including perinatal factors, infant feeding, and current lifestyle factors. Univariate analysis was performed first to compare the distribution of risk factors between cases and controls. Conditional logistic regression analysis was used to assess independent risk factors of childhood obesity. A total of 162 subjects (81 pairs of cases and controls) were included in the final analysis. The results showed that the adjusted odds ratios and 95% confidence intervals for childhood obesity were 8.88 (2.41-32.70), 5.23 (1.24-22.04), 10.96 (2.08-21.64), and 6.72 (1.55-29.12), respectively, for macrosomia, cesarean delivery, early solid foods initiation (<4 months), and fetal musical education. We conclude that macrosomia, cesarean delivery, early initiation of solid foods, and fetal musical education are associated with increased risk of obesity in preschool children in urban China.