Age-related differences in inflammatory biomarkers and acute kidney injury among hospitalized malaria patients in Luanda, Angola

Abstract

Malaria remains a leading cause of morbidity and mortality in sub-Saharan Africa; however, the clinical profiles of older adults with malaria are poorly characterized. Here, we investigated age-related differences in inflammatory burden and acute kidney injury (AKI) among hospitalized patients with malaria in Luanda, Angola. We conducted a cross-sectional study of 518 patients with malaria at two tertiary hospitals in Luanda, Angola, from January 2023 to December 2024. Logistic regression assessed associations between age group and inflammatory burden scores and AKI. Older adults (> 50 years) represented 9.8% of patients with malaria. After multivariable analysis, gender, ABO blood group, hemoglobin S (HbS), parasitemia, and AKI were not associated with age group (p > 0.05). In contrast, moderate [AOR: 0.40 (95% CI: 0.18–0.90), p = 0.028] and high inflammatory burden [AOR: 0.19 (95% CI: 0.04–0.91), p = 0.038] were associated with lower odds of being in the older age group. AKI was more frequent in older adults (35.3% vs 34.7%) and was associated with slightly increased odds (AOR: 1.09; p = 0.842), although this was not statistically significant. Patients over 50 years of age constituted a clinically distinct group among hospitalized malaria cases, characterized by a markedly reduced inflammatory response and a slight increase in acute kidney injury compared to younger patients, despite similar parasitemia. These findings highlight important age-related differences in the pathophysiology of malaria and reinforce the importance of including the elderly in targeted clinical and public health strategies in malaria-endemic areas.