Childhood central adiposity at ages 5 and 9 shows consistent relationship with that of the maternal grandmother but not other grandparents

Background: The importance of a life course approach to childhood obesity has been emphasized; however, few studies can prospectively investigate relationships in three-generation families.

Objective: To prospectively investigate the relationship between grandparental and grandchild waist circumference (WC) at ages 5 and 9 down maternal and paternal lines.

Methods: At baseline in the Lifeways Cross-Generation Cohort, 1094 children were born to 1082 mothers; 585 were examined at age 5 and 298 at age 9. Of the total 589 children with measured WC, data were also available from 745 grandparents. Child WC was standardized for age and sex, and theory-based hierarchical linear regression was used.

Results: Maternal grandmother (MGM) WC was predictive of grandchild WC at both time points. At age 5, grandchild's standardized birth weight (B = 0.266, p = 0.001), mother's means tested eligibility for free medical care (B = 1.029, p = 0.001) and grandchild seeing maternal grandparents daily (B = 0.312, p = 0.048) were significant alongside MGM WC (B = 0.015, p = 0.019). At age 9, only MGM WC (B = 0.022, p = 0.033) and mother's WC (B = 0.032, p = 0.005) were significant. Mediation analysis with mother's WC showed significant direct relationship of MGM and grandchild WC.

Conclusions: This prospective cross-generational cohort shows consistent patterns of association between MGM and grandchild WC, not seen in other grandparental lineages.