Correlation Between Parathyroid Hormone Level and Platelet Count and Morphology Indices in Patients on Maintenance Hemodialysis With Secondary Hyperparathyroidism (A Retrospective Study)

Abstract

Background: Chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients on maintenance hemodialysis exhibit hematological disturbances, including secondary hyperparathyroidism (SHPT) and platelet dysfunction. Platelet morphology indices—mean platelet volume (MPV), platelet distribution width (PDW), and platelet-large cell ratio (P-LCR)—provide insight into platelet reactivity. This study evaluated relationships between serum parathyroid hormone (PTH) and platelet parameters in end-stage renal disease patients undergoing hemodialysis.

Methods: This retrospective observational study included 79 adult hemodialysis patients (3 sessions/week) at Theodor Bilharz Research Institute, Egypt (January–July 2023). Demographic, clinical, and laboratory data were extracted. Statistical analyses included Spearman correlation, Kruskal-Wallis H, ANOVA with Tukey HSD, and Two-Way ANOVA.

Results: Serum PTH positively correlated with MPV (\rho = +0.448, p < 0.001) and P-LCR (\rho = +0.604, p < 0.001). Stratification into PTH tertiles (Low< 156 pg/ml, Mid 156–753 pg/ml, High >753 pg/ml) revealed a clear level- dependent increase for MPV (10.8 ± 1.3 vs 10.9 ±1.4 vs 12.3 ± 0.9 fL, p = 0.0004) and P-LCR (22.0 ± 8.1\% vs 28.0 ±10.1\% vs 37.1 ±10.0\%, p < 0.001). Patients with SHPT ({PTH} > 300 pg/ml) exhibited significantly higher median MPV (12.10 vs 10.45 fL, p = 0.008) and P-LCR (34.8\% vs 21.5\%, p < 0.001) compared to non-SHPT patients. No significant correlation or variance was observed for platelet count.

Conclusion: Elevated PTH is strongly associated with larger, immature, more reactive platelets (increased MPV and P-LCR) without affecting platelet count or PDW, suggesting SHPT influences platelet morphology rather than quantitative depletion.