The relationship between calcium-sensing receptor gene polymorphism and cardiovascular complications in hemodialysis patients

Abstract

Background Secondary hyperparathyroidism and cardiovascular complications are common in hemodialysis patients. Genetic variations in the calcium-sensing receptor (CaSR) gene may influence parathyroid hormone regulation and cardiovascular outcomes in this population. This study aimed to investigate the association between the CaSR rs1042636 polymorphism and echocardiographic findings among hemodialysis patients with hyperparathyroidism. Patients and methods This observational study included 25 adult hemodialysis patients receiving cinacalcet therapy at Mansoura Urology and Nephrology Center between November 2024 and November 2025. Patients were genotyped for CaSR rs1042636 polymorphism using TaqMan real-time PCR and divided into AG ( n =18) and GG ( n =7) groups. Demographic, clinical, dialysis-related, and laboratory data – including calcium, phosphate, intact parathyroid hormone (iPTH), and hematological parameters – were collected. Dialysis adequacy was assessed via single-pool Kt/V. Transthoracic echocardiography was performed to evaluate cardiac structure, systolic and diastolic function, valvular abnormalities, and left ventricular mass. Statistical comparisons between groups were performed using χ 2 or Student’s t test, with P value less than 0.05 considered significant. Results Baseline demographics, BMI, dialysis vintage, vascular access, and comorbidities were comparable between groups. No significant differences were observed in hematological parameters, calcium, phosphate, or cardiovascular events. GG patients had significantly lower iPTH compared with AG patients ( P =0.038). Echocardiographic evaluation revealed higher frequencies of valvular calcification, mitral regurgitation, and aortic regurgitation among AG patients. In contrast, tricuspid regurgitation, left ventricular hypertrophy, chamber dimensions, and ejection fraction were similar between groups. Conclusion The CaSR gene rs1042636 polymorphism is associated with differences in iPTH levels and valvular abnormalities among hemodialysis patients, suggesting a potential role of this genetic variant in modulating mineral metabolism and cardiovascular risk in this population.