Child Neglect And Body Mass Index (BMI) In Adulthood: A Sibling Study Nested In The FAMILY Cohort

Abstract

Background: Studies for child neglect and BMI are susceptible to unmeasured or unknown confounding by childhood environment and potential genetic disposition. Sibling studies minimize confounding from all shared childhood exposures and can thereby obtain more causally robust estimates.

Aims: To examine the association between child neglect and adult BMI using a sibling fixed effects design.

Key methods: Under Hong Kong FAMILY Project, a Jockey Club Initiative for a Harmonious Society, 471 sibling groups (1,050 participants age ³18 years) from the FAMILY Cohort were administered a child neglect scale including items on health, clothing, food, education and safe living conditions. BMI was analysed as a continuous score and as a binary outcome (overweight/obese: BMI ³ 23). Generalized linear mixed effects models predicting BMI and the odds of overweight/obese were fitted.

Results: 37.2% of adults reported childhood neglect, and 40.8% of sibling groups were discordant in exposure to child neglect. Within-sibling effects for BMI (b=-0.08, 95% CI: -0.68 to 0.52) and for overweight/obese (OR=1.45, 95% CI: 0.91 to 2.31) were not significant, adjusting for non-shared factors (age, sex, place of birth and parental occupation at age 10).

Conclusions: The sibling fixed effects model found no association between child neglect and BMI, controlling for shared unmeasured and unknown confounders. Future studies should...