The Correlation of Carotid Intima-media Thickness with Calcium-phosphorus Product in Patients Undergoing Maintenance Haemodialysis: A Cross-sectional Study

Introduction: The risk of Cardiovascular Disease (CVD) morbidity and mortality remains high in all stages of Chronic Kidney Disease (CKD). Elevated calcium and phosphorus have direct effects on vascular smooth muscle cells, promoting vascular calcification and arteriosclerosis. Carotid Artery IntimaMedia Thickness (CIMT) is a well-established index of systemic atherosclerosis and correlates with the incidence of coronary artery disease and stroke in the CKD population. Aim: To study levels of Serum Calcium-Phosphorus product (S. CaxP) and CIMT in patients undergoing Maintenance Haemodialysis (MHD) and to correlate CIMT with S. CaxP. Materials and Methods: This was a cross-sectional study conducted at the Department of General Medicine, K.R. Hospital (Krishna Rajendra Hospital), Mysore Medical College and Research Institute (MMCRI), Irwin Road, Mysuru, Karnataka, India over a period of one and a half years between January 2020 and July 2021. Data were collected from patients visiting the Outpatient Department (OPD) or those admitted for MHD, as well as through the medical records of stage 5 CKD patients who were admitted to the hospital for MHD. Subjects’ serum calcium, serum potassium, S. CaxP, and CIMT were evaluated. The Student’s t-test and the Chi-square test were employed to assess the significance between the groups. A p-value <0.05 was considered statistically significant. Results: Of the 76 individuals included in the study, 27 were females with mean age 44.07 years and 49 were males with a mean age 43.81 years. The mean CIMT among the study population was 1.2108±0.28966 mm, and the mean S. CaxP was 46.9237 mg²/dL². There was a positive correlation between CIMT values, S. Calcium, S. phosphorus, S. CaxP, and the duration of MHD. High S. CaxP is a significant and independent risk factor associated with advanced arteriosclerosis in CKD patients, independent of age, gender, Diabetes Mellitus (DM), Hypertension (HTN), and hyperlipidemia. Conclusion: Patients with CKD have a high risk of CVD. Although these patients share many cardiovascular risk factors with the general population, additional factors, such as abnormal calcium/phosphorus metabolism, elevate their risk for CVD. The present study concludes that there is a positive correlation between serum calcium-phosphorus product levels and CIMT, as well as with the duration of maintenance haemodialysis.