Sex Differences in Early Childhood Growth in a Resource-limited Setting: A Secondary Analysis of the Early Life Interventions in Childhood Growth and Development In Tanzania (ELICIT) Study.

Background In population-based growth surveys in sub-Saharan Africa, boys have higher rates of growth failure than girls. Objective Our goal was to assess for the presence, timing and potential etiology of sex-based differences in length-for-age z-score (LAZ), weight-for-age z-score (WAZ) and head-circumference-for-age z-score (HCZ) in a birth cohort in rural Tanzania. Methods We performed a secondary analysis of RCT data on 1084 children followed from age Results While male and female infants had similar anthropometry measures at study entry, males exhibited poorer growth through 6-months (e.g., 3-month mean LAZ: males -0.94, females -0.74, P Conclusions In longitudinal analysis, males exhibited more severe growth failure by 3-months than girls and did not exhibit catch-up growth between 6-18 months. Reported symptoms of illness and early introduction of CSL did not appear to be mediators of these sex-based differences, though likely not all sickness was captured by monthly maternal report. Given the early nature of these deficits, LAZ and WAZ measures at 6-months may be good outcomes for intervention studies targeting improvements in early childhood growth and thriving.