Early-life nutrition is associated with processing speed at age 5 in children born preterm with very low birth weight

Abstract

Objective: Processing speed is suboptimal among preterm-born children which is of concern as it is a foundational skill supporting higher-level cognitive functions. The study objective was to evaluate associations between early-life nutrition and processing speed in childhood.

Methods: Macronutrient and human milk (mother's own, donor) intakes from 137 children born preterm with very low birth weight enrolled in a nutrition feeding trial were included. Processing speed was evaluated at age 5 using the Wechsler Preschool and Primary Scale of Intelligence-fourth edition Processing Speed Index. Associations between early-life nutrition and processing speed were explored through linear regression.

Results: Children had a mean (standard deviation [SD]) birth gestational age of 28.1 (2.5) weeks, weight of 1036 (260) g and 52% were male. The mean (SD) assessment age was 5.7 (0.2) years. Sex-dependent relationships were identified between first postnatal month protein, lipid and energy intakes and processing speed at 5 years. For females, lower protein (per 0.1 g/kg/d: -0.88, 95% confidence interval [CI]: -1.53, -0.23; p = 0.01) and energy (per 10 kcal/kg/d: -2.38, 95% CI: -4.70, -0.05; p = 0.03) intakes were related to higher processing speed scores. Mother's milk provision was positively associated (per 10% increase: 0.80, 95% CI: 0.22, 1.37; p = 0.01) and donor milk was negatively associated (per 10% increase: -1.15, 95% CI: -2.22, -0.08; p = 0.04) with processing speed scores; no sex differences were observed.

Conclusions: First postnatal month nutrition was related to processing speed at age 5 in children born preterm with very low birth weight. Early-life nutrition that supports processing speed may be leveraged to improve later cognitive outcomes for this vulnerable population.

Keywords: cognition; human milk; macronutrient.