A new study by researchers from Addis Ababa University (AAU) and the International Food Policy Research Institute (IFPRI) provided a new insight about the largely overlooked role of residence at high altitude on child stunting.

The paper authored by Kaleab Baye (PhD; Associate Professor) at AAU and Kalle Hirvonen (PhD; Senior Research Fellow) at IFPRI was published in the Journal of the American Medical Association (JAMA), Pediatrics– the most cited pediatrics journal in the world.

The study is the first global analyses comprising close to one million children from 59 low and middle income countries examining altitude and child growth. The study showed that residence at high altitude is consistently linked with growth faltering, even after adjusting for as many confounding factors as possible, including diets, access to health care, and living conditions.

 “The data clearly indicated that those residing in ideal-home environments grew at the same rate as the median child in the growth standard developed by the World Health Organization (WHO), but only until about 500 meters above sea level (masl). After 500 masl, average child height-for-age significantly deviated from the growth curve of the median child in the reference population”, said Dr Hirvonen.

The study identified the perinatal period as the most vulnerable period. Pregnancies at high altitude are complicated by chronic hypoxia (suboptimal supply of oxygen), putting the fetus at risk for intrauterine growth restriction.

The authors’ conclude that the WHO growth standard does not need to be adjusted for altitude, but instead greater attention and health care guidance is needed to manage pregnancies at higher altitudes.

Currently, 12% of people live at altitudes higher than 1,500 meters above sea level, largely in Africa and Asia, regions that also have high levels of child stunting. Without interventions addressing altitude-mediated growth retardations, global child stunting reductions targets may not be achieved.

“A first step is to unravel the complex relationship linking altitude, hypoxia and fetal growth to identify effective interventions. Failing to address altitude-mediated growth deficits urgently can fail a significant proportion of the world population from meeting the Sustainable Development Goals and World Health Assembly nutrition targets” said Dr Baye.

Click to access the full study: “Evaluation of Linear Growth at Higher Altitudes”