Association between Red Blood Cell Indices and Hypertension Among Patients Attending Primary Health Care Centers in Libya

Hypertension is a major risk factor for cardiovascular disease, and identifying inexpensive laboratory markers associated with elevated blood pressure may improve early risk assessment in primary healthcare. This study investigated associations between red blood cell (RBC) indices and hypertension among patients attending primary health centers. A cross-sectional analytical study was conducted at the Sabratha and Surman Health Centers between January and July 2024, involving 326 participants (151 hypertensive patients and 175 normotensive patients). Hematological profiles were compared and correlated with blood pressure measurements. Hypertensive patients had significantly higher mean RBC counts (4.50 ± 0.58 vs. 4.38 ± 0.42 × 10¹²/L; p = 0.030), hemoglobin (12.79 ± 1.91 vs. 12.32 ± 1.66 g/dL; p = 0.019), hematocrit (38.14 ± 5.14 vs. 36.46 ± 4.11%; p = 0.001), mean corpuscular volume (85.12 ± 6.41 vs. 83.50 ± 7.16 fL; p = 0.033), and RDW-SD (44.44 ± 5.44 vs. 42.37 ± 5.24 fL; p = 0.001). Correlation analysis showed RBC count was positively associated with systolic (r = 0.205, p = 0.012) and diastolic blood pressure (r = 0.172, p = 0.034). Hemoglobin and hematocrit also correlated significantly with diastolic blood pressure, while RDW-SD showed a negative correlation (r = -0.160, p = 0.050). In conclusion, routine RBC parameters are significantly associated with hypertension and correlate with blood pressure levels. These indices may serve as accessible, low-cost biomarkers for hypertension risk assessment in primary healthcare settings.