Relation between body composition at birth and child development at 2 years of age: a prospective cohort study among Ethiopian children.

BACKGROUND/OBJECTIVES: Birth weight (BW), independent of socioeconomic status, has been identified as a predictor for childhood cognitive development. However, it is not known whether this relation is related to low BW per se or particularly related to a deficit in fat mass (FM) or fat-free mass (FFM) at birth. This study therefore aimed at investigating the relation between body composition at birth and child development at 2 years of age. SUBJECTS/METHODS: An Ethiopian birth cohort was followed up at 2 years. Body composition was measured within 48 h of birth using infant air-displacement plethysmography. Child development was assessed at 2 years of age using Denver developmental screening test. Associations between body composition at birth and development at 2 years of age were tested using linear regression analysis. RESULTS: FFM but not FM at birth was positively associated with higher global developmental score at 2 years of age (ß=2.48, 95% confidence interval (CI) 0.17; 4.79) adjusted for neonatal, postnatal and parental characteristics. This association was attributable to the association with the language developmental domain (ß=1.61, 95 CI 0.33; 2.90). CONCLUSIONS: Among Ethiopian children, FFM at birth but not FM predicted better global and language development at 2 years of age. Higher FFM at birth might have exerted a positive effect on the growth and differentiation of the brain and neuronal circuits for better development. This study therefore highlights the need to improve mother's nutritional status during pregnancy in ways that stimulate fetal FFM growth.

Calibration of bioelectrical impedance analysis for body composition assessment in Ethiopian infants using air-displacement plethysmography.

BACKGROUND/OBJECTIVES: Assessment of infant body composition (BC) is crucial to understand the consequences of suboptimal nutritional status and postnatal growth, and the effects of public health interventions. Bioelectrical impedance analysis (BIA) is a feasible, relatively inexpensive and noninvasive method for assessing BC. However, very little research has been conducted in low- and middle-income populations, where efforts to prevent or treat malnutrition in early life are a public health priority. We aimed to develop equations for predicting fat-free mass (FFM) and fat mass (FM) based on BIA in 0- to 6-month-old Ethiopian infants. SUBJECTS/METHODS: The study comprised a total of 186 BC assessments performed in 101 healthy infants, delivered at Jimma University Specialized Hospital. Infant air-displacement plethysmography (IADP) was the criterion method, whereas weight, length, sex, age and an impedance index (L(2)/Z50) were predictors. Prediction equations were developed using stepwise multiple linear regression and the accuracy was evaluated with a 10-fold cross-validation approach. RESULTS: A linear regression model based on body weight, age and sex predicted FFM, estimated by IADP, with an adjusted R(2) and root mean square error (RMSE) of 0.94 and 200 g, respectively. Adding impedance index to the model resulted in a significantly improved model fit (R(2)=0.95; RMSE=181 g). For infants below 3 months of age, inclusion of impedance index did not contribute to an improved model fit for predicting FFM compared with a model already comprising weight, sex and age. CONCLUSIONS: The derived equations predicted FFM with acceptable accuracy and may be used in future field surveys, epidemiological studies and clinical trials conducted in similar sub-Saharan African population groups aged 0-6 months.