ESPE Yearbook of Paediatric Endocrinology

To read the full abstract: Lancet Glob Health 2017; 5(12):e1249-e1257

This paper adds to the understanding of the factors underlying stunting in low-and middle-income countries (LMIC), a phenomenon that is adaptive to undernutrition, and associates with overall poorer health status and unfavorable social determinants of health. Previously thought to be secondary to predominantly individual and household-level factors, this study elegantly demonstrates that stunting in LMICs can primarily be attributed to population-wide community-level factors.

The authors first used statistical modeling to demonstrate how the trends of the HAZ population mean, standard deviation (SD), and 5^th and 95^th centiles change based on the proportion of the population that is exposed to factors impairing growth. If a trend is driven by only subgroup, the population SD increases, whereas the SD remains steady if the trend occurs across the whole population. The study team then analyzed cross-sectional data from 0-3 year-old children from Demographic and Health Surveys (DHS) in 64 LMIC, including over half in sub-Saharan Africa and none in North America, to assess the trajectory of early childhood HAZ, and evaluate for individual vs. population-driven growth faltering. They demonstrate that the overall mean HAZ declined over time, confirming early childhood growth faltering, and that across regions the HAZ dispersion remained symmetric during the first 3 years of life when growth faltering is most likely to occur, suggesting that the overall mean HAZ decline over time is experienced by children across the entire HAZ z-score spectrum rather than only by a high-risk group such as the extremely stunted.

While the study’s limitations include factors inherent to survey-based data, including anthropometric measurement errors and sample heterogeneity, its results supported by consistent multiple well-designed sensitivity analyses. Early childhood stunting in LMIC may be less attributable to different individual genetic, epigenetic and environmental exposures, but rather may be rooted in community-level social and macroeconomic factors. This represents an important public health concern that needs further in-depth study.