Associations of fat and fat-free mass at birth and accretion from 0-5 years with cognitive function at later childhood: The Ethiopian iABC birth cohort

Early childhood growth is associated with cognitive function. However, the independent associations of fat mass (FM) and fat-free mass (FFM) with cognitive function are not well understood. We investigated associations of FM and FFM at birth and 0-5 years accretion with cognitive function at 10 years. Healthy term newborns were enrolled in this cohort. FM and FFM were measured at birth, 1.5, 2.5, 3.5, 4.5, 6 months, 4 and 5 years. Cognitive function was assessed using Peabody Picture Vocabulary Test (PPVT) at 10 years. FM and FFM accretion were computed using statistically independent conditional accretion from 0-3 months, 3-6 months, 6 months-4 years, and 4-5 years. Multiple linear regression was used to assess associations. At the 10-year follow-up, we assessed 318 children with mean (SD) age of 9.8 (1.0) years. A 1 SD higher birth FFM was associated with a 0.14 SD (95% CI: 0.01, 0.28) higher PPVT at 10 years . FFM accretion from 0-3 and 3-6 months was associated with PPVT at 10 year, β = 0.5 SD (95% CI: 0.08, 0.93 ) and β = -0.48 SD (95% CI: -0.90, -0.07 , respectively . FFM accretion after 6 months showed no association with PPVT. Neither FM at birth nor 0-5 years accretion showed association with PPVT. Overall, b irth FFM, but not FM was associated with cognitive function at 10 years, while t he association of FFM accretion and cognitive function varied across distinct developmental stages in infancy . The mechanisms underlying this varying association between body composition and cognitive function need further investigation.