Low plasma selenium concentrations, high plasma human immunodeficiency virus load and high interleukin-6 concentrations are risk factors associated with anemia in adults presenting with pulmonary tuberculosis in Zomba district, Malawi

Abstract

Although anemia is common among adults with pulmonary tuberculosis and human immunodeficiency virus (HIV) infection in sub-Saharan Africa, the factors contributing to its pathogenesis have not been well characterized. To characterize the antioxidant micronutrient status, interleukin-6 (IL-6) concentrations, and HIV load in relationship with anemia in adults with pulmonary tuberculosis. Zomba district, Malawi. Erythropoietin, IL-6, plasma HIV load, and markers of micronutrient status (hemoglobin (Hb), plasma concentrations of retinol, alpha-tocopherol, carotenoids, ferritin, zinc, and selenium) were measured in 500 adults who presented with pulmonary tuberculosis in Zomba Central Hospital, Malawi. Among 370 HIV-positive and 130 HIV-negative adults, the prevalence of anemia was 88 and 77%, respectively (P = 0.002), and moderate to severe anemia (Hb < 80 g/l) occurred in 30 and 15%, respectively (P = 0.001). Geometric mean IL-6 concentration was 21.1 pg/ml, with no difference between HIV-positive and -negative adults. The erythropoietin response to anemia was not different between adults with elevated IL-6 and those with lower IL-6 concentrations. In a multivariate logistic regression model, HIV load, and lower plasma selenium concentrations were associated with moderate to severe anemia. In a final multivariate linear regression model, IL-6, plasma HIV load, and plasma selenium concentrations were associated with Hb concentrations. This study suggests that low selenium concentrations, high HIV load, and high IL-6 concentrations are associated with anemia in adults with pulmonary tuberculosis in sub-Saharan Africa.