Adiposity rebound from three to six years of age was associated with a higher insulin resistance risk at eight-and-a-half years in a birth cohort study.

Aim: The association between adiposity rebound and insulin resistance in middle childhood has seldom been studied. We examined the effect of body mass index (BMI) velocity and early adiposity rebound on the insulin resistance of prepubertal children.

Methods: BMI data from a longitudinal follow-up of a birth cohort in Thailand were used. The homoeostatic model assessment of insulin resistance (HOMA-IR) was calculated from 12-hour fasting plasma glucose and serum insulin at eight-and-a-half years of age. BMI velocity was calculated from four periods: zero to one, one to three, three to six and six to eight-and-a-half years of age. A multiple linear regression model was used to assess the association of BMI velocity during these four periods and insulin resistance at the age of eight-and-a-half years.

Results: In 814 children - 76.7% of the initial cohort - BMI velocities between years one to three, three to six and six to eight-and-a-half years were positively associated with HOMA-IR levels after adjusting for demographic, behavioural and socio-economic factors. Children who had BMI gains between three and six years had mean HOMA-IR values that were 43% higher than those who did not.

Conclusion: BMI velocity during early and middle childhood, and early adiposity rebound between three and six years, was associated with a higher insulin resistance risk at eight-and-a-half years.