Abstract

Background: This study aimed to explore the patterns in body mass index trajectories and obesity onset, as well as the prevalence of childhood obesity, among Japanese children with intellectual disabilities (ID) (including Down syndrome; DS).
Methods: We evaluated 231 students (6–18 years old) who were receiving special needs education. Obesity was calculated via the Rohrer index and Japanese obesity index, which used height and body weight data that were obtained during the children’s annual school health monitoring check-up. Data regarding a diagnosis of DS were obtained from their entrance applications, which were completed by the children’s parents. Chi square and Mann-Whitney U tests were used to test the associations between obesity, sex, and DS. Body mass index trajectory patterns were evaluated by fitting a semiparametric mixture model.
Results: The highest prevalences of obesity among Japanese children with ID were 25.8% among 6–8-year-old boys and 21.1% among 15–17-year-old girls. The onset of obesity was most likely to occur at the ages of 8 years and 12 years in this study.
Conclusion: Japanese children with ID have a higher prevalence of obesity (compared to non-ID children), and the onset of obesity predominantly occurred at the ages of 8 years and 12 years. Although the prevalences of obesity were similar for children with and without DS, children with DS had a significantly higher obesity index. These findings suggest that children with DS may easily develop serious obesity.