Comparison of Serum Calcium, Phosphorus, Alkaline Phosphatase, and Intact Parathyroid Hormone Levels Between Dialysis-Dependent and Non-Dialysis-Dependent Patients With Chronic Kidney Disease: A Cross-Sectional Observational Study

BackgroundChronic kidney disease (CKD) is frequently accompanied by chronic kidney disease-mineral and bone disorder (CKD-MBD), a systemic complication characterised by biochemical abnormalities in serum calcium, phosphorus, alkaline phosphatase (ALP), and intact parathyroid hormone (iPTH), which may contribute to bone disease, vascular calcification, cardiovascular morbidity, and adverse clinical outcomes. AimThis study aimed to compare serum calcium, phosphorus, ALP, iPTH, and calcium-phosphorus product levels between dialysis-dependent and non-dialysis-dependent patients with CKD and to assess the associations of these biochemical parameters with dialysis duration. Materials and methodsThis hospital-based comparative observational study included 120 adults with CKD attending a tertiary care centre in Kanpur, India, comprising 60 dialysis-dependent and 60 non-dialysis-dependent patients aged 18-65 years with CKD stages 3-5.Patients were enrolled consecutively during the eight-month study period following Institutional Ethics Committee approval.Serum calcium, phosphorus, ALP, and iPTH values were obtained as part of routine clinical evaluation and retrieved from the patients' hospital records.In dialysisdependent patients, blood samples were collected before a scheduled hemodialysis session; in non-dialysisdependent patients, values were obtained from routine clinical laboratory assessments.The calciumphosphorus product (Ca × P) was calculated from the recorded calcium and phosphorus values.Statistical analysis was performed using IBM SPSS Statistics, version 26.0 (IBM Corp., Armonk, NY, USA), with p < 0.05 considered statistically significant. ResultsSerum calcium was significantly lower, whereas serum phosphorus, ALP, iPTH, and calcium-phosphorus product were significantly higher in dialysis-dependent than in non-dialysis-dependent patients with CKD (all p < 0.001).All dialysis-dependent patients had stage 5 CKD.Among dialysis-dependent patients, dialysis duration showed significant positive correlations with serum phosphorus, ALP, and iPTH and a significant negative correlation with serum calcium. ConclusionCKD-MBD abnormalities were more pronounced in dialysis-dependent than in non-dialysis-dependent patients with CKD.Longer dialysis duration was associated with lower serum calcium and higher serum phosphorus, ALP, and iPTH levels.These findings support regular surveillance of these biochemical parameters for timely recognition and management of CKD-MBD.