The relationship between residential altitude and stunting: evidence from >26 000 children living in highlands and lowlands of Ethiopia

Abstract

Little information is known about the influence of altitude on child growth in Ethiopia, where most people live in highlands. We investigated the relation of residential altitude with growth faltering (stunting) of infants and young children in Ethiopia. We also examined whether the altitude–growth relationship was independent of the influence of the dietary and non-dietary determinants of growth. We used the data of 26 976 under-5-year-old children included in the Ethiopian Demographic and Health Surveys, conducted from 2005 to 2016. The samples were recruited following a two-stage cluster sampling strategy. Stunting was defined by height-for-age <−2 z-scores. The relationship between residential altitude and stunting was examined by running multiple logistic regression analysis, controlling the effect of covariate dietary and non-dietary variables. The residential altitude of the study participants ranged from −116 to 4500 m above sea level (masl). There was a significant and progressive increase in the prevalence and odds of stunting with increasing altitude (P < 0·001), irrespective of the dietary and non-dietary predictors of stunting. The prevalence of stunting was lowest in lowlands (39 %) and highest in highlands (47 %). Compared with altitude <1000 masl, the odds of stunting was 1·41 times higher at altitude ≥2500 masl (OR 1·41, 95 % CI 1·16, 1·71) and 1·29 times higher at altitude 2000–2499 masl (OR 1·29, 95 % CI 1·11, 1·49). Children living in highlands might be at a higher risk of poor growth. Further studies are warranted to understand the mechanism behind the observed altitude–stunting link and identify strategies to compensate for the growth-faltering effect of living in highlands.

The Effect of Socioeconomic and Behavioral Factors on Childhood Stunting in Janamora District, Ethiopia

“…This finding is in line with other studies done in Bahir Dar city (42.5%), 24 Holeta town, Oromia regional state (48.2%), 25 in Bule-Hora district (47.6%), 26 Harmaya (45.8%), 27 East Badawacho district (45.6%), 28 the high land area of Ethiopia (47%), 29 and Nigeria (47.6%). 4 However, this finding is higher than mini-EDHS 2019 (37%), 10 Amhara region report (41.3%), 29 Sodo Zuria district (24.9%), 30 Hosanna town (35.4%), 7 in Shey bench district, Southwest Ethiopia (33.3%), 22 and Korahay Zone, Somalia regional state (31.9%), 22 Sudan (24.9%), 31 and Bangladesh (41%). 5 The reason for this discrepancy might be differences in altitude.…”

Elevation and Child Linear Growth in Nepal

“…We expect that researchers studying children living in similarly remote communities (as has been documented in, for example, Tibet, Peru, and Bolivia) would find similar patterns, both because economic circumstances in these similarly remote areas are sufficiently comparable, and because our socioeconomic controls reduced the extent to which socioeconomic differences between these locations could drive regression results. Our findings suggest a moderate reduction in linear growth for children at high elevations, and they are consistent with findings reported from other locations, including Tibet (Argnani et al 2008), Argentina (Roman et al 2015), and Ethiopia (Mohammed et al 2020). Future studies that combine samples would strengthen our confidence that elevation, and not unobserved country-specific factors, is driving this pattern.…”

“…Future research for Nepal and elsewhere might attempt to account for dietary factors directly. For example, in a recent study of Ethiopian children living at high elevation, Mohammed et al (2020) found a negative association between height and elevation while controlling for household dietary diversity, measured using 24 hour recall data on 7 food groups. This suggests that the elevation relationship is robust to the inclusion of dietary measures.…”

“…Recent research has reinforced these findings in studies similar to ours. Studies using data from high-elevation areas in Tibet (Argnani et al 2008), Argentina (Roman et al 2015), and Ethiopia (Mohammed et al 2020) have shown a negative and statistically significant association between elevation and linear growth, with children living above 2000 masl facing increased odds of stunting of 28-29%, and children living at higher elevations (3000 masl or more) facing even greater risk.…”

Altitude and early child growth in 47 countries

“…For example, altitude was found to be a significant predictor of linear growth at birth, 6 months, and 1 year for Bolivian children living at 3600 m above sea level (masl) compared to their counterparts living at 400 masl, and similar findings were later reported for a different Bolivian sample, as well as for children in the US mountain west and Tibet (Argnani et al, 2008;Dang et al, 2007;Greksa et al, 1985;Haas et al, 1982;Wang et al, 2016;Zahran et al, 2014). Studies from high-altitude areas in Argentina (Roman et al, 2015), and Ethiopia (Mohammed et al, 2020) have also found negative and statistically significant associations between altitude and linear growth, with children living beyond 2000 masl facing 28 percent greater odds of stunting, and children living at higher altitudes facing even greater risks.…”