Body Composition Trajectories During the First 23 Months of Life Differ by HIV Exposure Among Infants in Western Kenya: A Prospective Study

Abstract

Background: Infants who are HIV-exposed and uninfected have suboptimal growth patterns compared to those who are HIV-unexposed and uninfected. However, little is known about how these patterns persist beyond 1 year of life.

Objectives: This study aimed to examine whether infant body composition and growth trajectories differed by HIV exposure during the first 2 years of life among Kenyan infants using advanced growth modeling.

Methods: Repeated infant body composition and growth measurements (mean: 6; range: 2-7) were obtained from 6 weeks to 23 months in the Pith Moromo cohort in Western Kenya (n = 295, 50% HIV-exposed and uninfected, 50% male). Body composition trajectory groups were fitted using latent class mixed modeling (LCMM) and associations between HIV exposure and growth trajectories were examined using logistic regression analysis.

Results: All infants exhibited poor growth. However, HIV-exposed infants generally grew suboptimally than unexposed infants. Across all body composition models except for the sum of skinfolds, HIV-exposed infants had a higher likelihood of belonging to the suboptimal growth groups identified by LCMM than the HIV-unexposed infants. Notably, HIV-exposed infants were 3.3 times more likely (95% CI: 1.5-7.4) to belong to the length-for-age z-score growth class that remained at a z-score of < -2, indicating stunted growth. HIV-exposed infants were also 2.6 times more likely (95% CI: 1.2-5.4) to belong to the weight-for-length-for-age z-score growth class that remained between 0 and -1, and were 4.2 times more likely (95% CI: 1.9-9.3) to belong to the weight-for-age z-score growth class that indicated poor weight gain besides stunted linear growth.

Conclusions: In a cohort of Kenyan infants, HIV-exposed infants grew suboptimally compared to HIV-unexposed infants beyond 1 year of age. These growth patterns and longer-term effects should be further investigated to support the ongoing efforts to reduce early-life HIV exposure-related health disparities.

Keywords: HIV-exposed uninfected; WHO z-scores; Western Kenya; body composition; food insecurity; infant growth; infant growth epidemiology; infant growth trajectories; nutritional epidemiology.

FIGURE 1

Unadjusted growth plots of all infants included in the analytic sample from 6 weeks to 23 months in Kenyan infants in the Pith Moromo study. Growth plots for all growth and body composition measurements are shown. The y-axes are different for each measurement as they depend on the anthropometric values or z-score value because of which, some axes do not start at zero.

FIGURE 2

Three-class latent class mixed models and corresponding multinomial logistic regression estimates showing the relative risk ratio (95% CI) for the likelihood of being in each class relative to the reference class. Trends of trajectory classes by anthropometric measures indicate that subgroups experience distinct differences in growth patterns over time.

FIGURE 3

Four-class latent class mixed models and corresponding multinomial logistic regression estimates showing the relative risk ratio (95% CI) for the likelihood of being in each class relative to the reference class. Trends of trajectory classes by anthropometric measures indicate that subgroups experience distinct differences in growth patterns over time.