The Relationship Between Serum Calcium-Phosphate Product Levels and Pulse Pressure Variability in Patients Undergoing Routine Hemodialysis at Adam Malik Hospital

Abstract

Background: Chronic kidney disease (CKD) is a major global health problem associated with high morbidity and mortality, primarily due to cardiovascular complications. Among patients undergoing long-term hemodialysis, arterial stiffness and vascular calcification are common and can be reflected through increased pulse pressure variability. The calcium–phosphate product (Ca × P) represents a key indicator of mineral metabolism disorders that may contribute to vascular calcification and hemodynamic abnormalities in dialysis patients.

Objective: To analyze the relationship between serum calcium–phosphate product levels and pulse pressure variability in patients undergoing routine hemodialysis at Adam Malik Hospital, Medan.

Methods: This analytical observational study with a cross-sectional design included 60 patients with chronic kidney disease receiving regular hemodialysis. Data were collected through interviews, medical record reviews, physical examinations, and laboratory tests. Serum calcium and phosphate levels were measured before dialysis, and the calcium–phosphate product was calculated by multiplying both values. Pulse pressure was obtained by subtracting diastolic from systolic blood pressure. Statistical analysis was performed using the Spearman rank correlation test, with a significance level of p < 0.05.

Results: The mean serum calcium level was 8.24 ± 0.83 mg/dL, and the mean serum phosphate level was 5.45 ± 1.22 mg/dL. The average calcium–phosphate product was 44.93 ± 10.62 mg²/dL², while the mean pulse pressure was 61.35 ± 12.24 mmHg. A weak positive correlation was found between calcium–phosphate product and pulse pressure variability (r = 0.216, p = 0.098), indicating no statistically significant relationship.

Conclusion: The study found no significant association between serum calcium–phosphate product levels and pulse pressure variability among patients undergoing routine hemodialysis. Although a positive trend was observed, it was not statistically meaningful. These findings suggest that other factors, including hypertension, dialysis duration, and metabolic conditions, may have a greater impact on vascular stiffness. Routine monitoring of calcium, phosphate, and pulse pressure remains essential for early detection and prevention of cardiovascular complications in chronic hemodialysis patients.