Body composition of children born HIV-exposed uninfected in rural Zimbabwe

Background: Globally, 15 million children were born HIV-exposed uninfected (CHEU) from mothers living with HIV. CHEU have increased mortality, morbidity and stunting compared to children HIV-unexposed (CHU). Our objective was to compare body composition between CHEU and CHU, which may underlie this vulnerability. Methods: In a substudy among 223 children (36 CHEU and 187 CHU) enrolled in the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial in rural Zimbabwe, we measured height, knee-heel length, weight, calf circumference, skinfold thicknesses (triceps, subscapular and calf), and bio-electrical impedance at 2 years of age. Generalised estimating equations were used to compare body composition between CHEU and CHU, and interactions with linear growth and birthweight. Results: CHEU had significantly lower length-for-age, knee-heel length, weight-for-age, mid-upper arm circumference and calf circumference compared to CHU. CHEU had a lower impedance index (adjusted mean difference −0.49, 95% CI −0.87, −0.11), reflecting less lean mass, and lower skinfold thicknesses (subscapular Z-score adjusted mean difference −0.49 (95% CI −0.97, −0.02); triceps Z-score −0.48 (95% CI −0.83, −0.13)), indicating reduced subcutaneous fat. In early-life, CHEU had lower birthweight. However, no significant interaction between stunting or birthweight and HIV exposure was observed for body composition outcomes. Conclusion: CHEU have a distinct pattern of body composition by 2 years of age, characterised by reduced lean and fat mass compared to CHU which was not explained by reduced linear growth or lower birthweight. This pattern of early-life growth may contribute to the increased vulnerability of CHEU to mortality, morbidity and reduced neurodevelopment.