Trajectories of Physical Growth across Early Childhood Are Associated with Electroencephalography Power

Chronic malnutrition, commonly indexed using anthropometric indicators, is linked to deficits in multiple domains of children's development. Alterations to brain development have been found to partially explain these links, yet the mechanisms and timing underlying these relations are not well understood. Electroencephalography (EEG) is well suited to examining early neural correlates of anthropometric indicators, but longitudinal evidence is limited.

This study explored the presence and timing of relations between physical growth and EEG resting-state power across early childhood in a population with high rates of chronic malnutrition.

Data were drawn from a longitudinal, observational study of 130 children (74 females) living in Dhaka, Bangladesh. Anthropometric measures, including height-for-age Z-scores (HAZ) and stunting status, were collected 14 times from 3 to 54 mo old. Resting-state EEG power data were collected at ∼6 mo, 2 y, and 5.5 y old. Linear mixed-effects models were used to estimate growth trajectories and examine relations between anthropometric indicators and EEG power.

Findings revealed nonlinear changes in both HAZ and EEG over the first 5 years. HAZ scores decreased from 9 to 24 mo (b = -0.03, SE = 0.004, P < 0.001) but increased from 30 to 54 mo (b = 0.02, SE = 0.00, P < 0.001). Substantial variation in recovery status from stunting was seen. Exposure to stunting or static measures of HAZ was not associated with EEG power, but steeper positive trajectories of HAZ were related to higher EEG power (b = 1.07, SE = 0.40, P = 0.008).

These results suggest that both physical growth and EEG power development are dynamic over the first 5 years of life. The findings also highlight how longitudinal measures, including growth trajectories, can provide nuanced insights to complement static measures of anthropometry in Bangladesh.