The Association Between Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios and Anemia in Adults with Hypertension in Southwestern Uganda: A Cross-Sectional Study

Abstract

Purpose:: This study aimed to determine the association of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) with anemia among hypertensive patients in Southwestern Uganda. Patients and Methods: We conducted a secondary analysis of a cross-sectional study involving 386 consecutively enrolled hypertensive patients at Bwizibwera Health Centre IV, Mbarara District, Uganda. Anemia was defined as hemoglobin < 12.0 g/dL in women and < 13.0 g/dL in men. Data were analyzed using STATA. Categorical variables were compared using chi-square or Fisher’s exact tests, continuous variables with the Mann–Whitney U -test. Logistic regression examined associations of NLR, PLR, and monocyte-to-lymphocyte ratio (MLR) with anemia. Predictive performance was assessed using receiver operating characteristic (ROC) curves. Results: Overall anemia prevalence was 17.1% (95% CI: 13.7– 21.2). Prevalence was significantly higher among participants with uncontrolled versus controlled blood pressure (20.8% vs 12.6%; p=0.035). Anemic participants had significantly higher NLR (1.49 vs 1.14; p< 0.001), PLR (156.06 vs 118.45; p< 0.001), and MLR (0.23 vs 0.20; p=0.006). High NLR and PLR were independently associated with anemia. Participants in the top tertile of NLR had over twice the odds of anemia compared to those in the bottom tertile (aOR=2.29; 95% CI: 1.04– 5.07; p=0.040). Similarly, those in the top tertile of PLR had higher odds of anemia (aOR=2.28; 95% CI: 1.05– 4.97; p=0.038). Both ratios showed significant predictive ability to distinguish anemic from non-anemic participants: NLR AUC=0.63 (95% CI: 0.56– 0.71); PLR AUC=0.64 (95% CI: 0.56– 0.72). Conclusion: In hypertensive patients, higher NLR and PLR are independently associated with anemia. These inexpensive, readily available inflammatory hematological ratios may help identify individuals at elevated anemia risk. Keywords: anemia, hypertension, hematological ratios, Uganda