Ecuador’s high-altitude adults show elevated ALL mortality

A nationwide ecological study of Ecuador found significantly higher mortality from acute lymphoblastic leukemia (ALL) among adults living above 2,000 metres than among sea-level residents, while children in several lower-elevation areas showed lower rates. The analysis included 3,074 ALL-related deaths recorded across all 221 Ecuadorian cantons from 2011 through 2022 and identified geographic patterns that differed by age and biological sex. Because the study used deaths and population data aggregated by administrative area, its findings show an association with elevation rather than proving that altitude causes the differences in mortality.

Researchers combined Ecuador’s National Institute of Statistics and Censuses mortality register with official cantonal elevation data and population figures from the 2010 census. To assess broad geographic trends and reduce rate instability associated with small numbers of deaths in smaller administrative units, they pooled cantons into six 500-metre altitudinal strata: sea level, below 500 metres; low, 500–999 metres; moderately low, 1,000–1,499 metres; moderate, 1,500–1,999 metres; moderately high, 2,000–2,499 metres; and high, at least 2,500 metres. The nationwide scope covered 12 years of mortality records, allowing investigators to compare average annual age-specific mortality rates across the country’s elevation gradient.

The investigators calculated average annual age-specific mortality rates per 100,000 people, separating people younger than 18 from adults aged 18 or older and stratifying the analysis by biological sex. Exact Poisson 95% confidence intervals quantified uncertainty in the rates. Mortality rate ratios, assessed with 95% log-Wald confidence intervals, compared each higher-elevation stratum with the sea-level group. The clearest adult excess appeared in the 2,000–2,499-metre band: compared with sea level, the mortality rate ratio was 2.02 for men, with a 95% confidence interval of 1.67–2.45, and 1.83 for women, with a 95% confidence interval of 1.50–2.23. Both comparisons had p-values below 0.001, indicating statistically significant differences from the reference group.

Adult mortality also remained significantly elevated in the highest band, at least 2,500 metres above sea level. The mortality rate ratio was 1.72 for men, with a 95% confidence interval of 1.50–1.97, and 1.65 for women, with a 95% confidence interval of 1.43–1.90; both p-values were below 0.001. These estimates correspond to adult ALL mortality rates about 72% higher for men and 65% higher for women than the sea-level reference rates. The reported results therefore support the authors’ description of higher adult mortality above 2,000 metres, but the ecological design does not identify the individual-level factors behind the geographic contrasts.

Children showed a different pattern, with lower mortality at selected lower elevations rather than an excess at higher elevations. In the 500–999-metre band, the mortality rate ratio for boys younger than 18 was 0.59, with a 95% confidence interval of 0.39–0.90. At 1,000–1,499 metres, the ratio for pediatric males fell to 0.43, with a 95% confidence interval of 0.19–0.97. Pediatric females had a lower rate only in the 1,000–1,499-metre stratum, where the ratio was 0.31 and the 95% confidence interval was 0.10–0.97. All three comparisons had p-values below 0.05. These results support the reported inverse, age-dependent pediatric pattern, which contrasts with the elevated adult rates measured above 2,000 metres.

The study’s authors said the findings could inform regional health planning across the Andes, where communities at different elevations may face distinct disease patterns. They also identified potential biological mechanisms involving hypoxia-inducible factor pathways as subjects for further investigation and called for prospective research incorporating individual-level clinical, genetic and socioeconomic data. The current analysis treated elevation as a marker of macro-environmental conditions and did not directly measure individual clinical characteristics or personal environmental exposure. Its results are therefore observational and ecological: the reported rate ratios document population-level associations between canton-level elevation and ALL mortality, not causal effects of altitude or proof of a biological mechanism.

Subject of Research: Age-specific acute lymphoblastic leukemia mortality across Ecuadorian elevation gradients

Article Title: Spatial distribution and age-specific geodemographic patterns of Acute Lymphoblastic Leukemia (ALL) mortality in Ecuador: an ecological analysis across elevation gradients (2011–2022)

Article References: García-León, X., Fernández-Moreira, E., del Moral, M. G., Ballaz, S., Chamorro, K., & Gómez-García, A. R. (2026). Spatial distribution and age-specific geodemographic patterns of Acute Lymphoblastic Leukemia (ALL) mortality in Ecuador: an ecological analysis across elevation gradients (2011–2022). BMC Public Health. https://doi.org/10.1186/s12889-026-29730-x

Image Credits: AI Generated

DOI: 10.1186/s12889-026-29730-x

Keywords: acute lymphoblastic leukemia, Ecuador, mortality rates, elevation gradient, ecological analysis, pediatric mortality, adult mortality, Andes, geodemographic patterns, population health, Spatial, distribution