PROPORTIONAL MORTALITY FROM COVID-19 BY ALTITUDE IN DEATH CERTIFICATES OF PEOPLE WITH DIABETES DURING THE FIRST WAVE IN PERU

Introduction: Proportional mortality from COVID-19 among individuals with diabetes mellitus (DM) has been reported to be lower at higher altitudes. Objective: To examine proportional mortality from COVID-19 by altitude using death certificates of individuals with DM in Peru. Methods: A cross-sectional, population-based study using census data from the National Death System (SINADEF, by its Spanish acronym) was conducted between March 1 and December 31, 2020. The primary outcome was the proportion of deaths attributed to COVID-19 among all deaths in people with DM. The altitude of the district of death was categorized as <1500, 1500-2499, and ≥2500 meters above sea level. Crude and adjusted prevalence ratios (cPR, aPR) were estimated. Results: A total of 16, 406 deaths were analyzed, with 34.3% attributed to COVID-19. Living at ≥2500 meters was associated with lower proportional mortality compared with <1500 meters (aPR: 0.80; 95% CI: 0.75-0.88). When altitude was modeled as a continuous variable, the aPR declined by 4% for every 500-meter increase (aPR: 0.96; 95% CI: 0.94-0.98). Conclusions: In 2020, proportional mortality from COVID-19 among individuals with DM was lower at higher altitudes. These findings highlight an ecological pattern derived from death certificates and should be interpreted with caution given administrative data limitations, including potential mismatch between place of residence and place of death, and lack of adjustment for structural factors. The study provides exploratory evidence in the context of DM, which may inform future research using more precise measures of residence, mobility, and healthcare access.