The start of renal replacement therapy is a critical period for assessing cardiovascular risk. Recently, researchers investigated how serum calcium levels at the initiation of hemodialysis relate to the coronary artery calcium score (CACS). This cross-sectional study analyzed 176 adults who started dialysis between 2015 and 2023. They measured both ionized calcium and albumin-corrected calcium to determine their association with significant vascular calcification. Consequently, the findings offer new insights into mineral metabolism management during the transition to dialysis.

The study found a clear link between higher calcium and increased CACS. Specifically, ionized calcium showed a stable, linear association with a CACS ≥ 400. In contrast, albumin-corrected calcium displayed a convex pattern, particularly in patients with low albumin. This suggests that Payne’s formula may overestimate physiologically active calcium in certain patient groups. Therefore, clinicians might find ionized calcium to be a more reliable marker for risk stratification. Moreover, this accuracy is vital for preventing the progression of cardiovascular disease in uremic environments.

Impact of Serum Calcium Levels on Vascular Risk

Vascular calcification is highly prevalent among Indian dialysis patients, often exceeding 50% in clinical cohorts. Elevated serum calcium levels contribute significantly to this burden. Because ionized calcium represents the biologically active fraction, it provides a more accurate picture of mineral metabolism than corrected total calcium. Thus, using ionized calcium measurements could help nephrologists identify high-risk patients earlier. Furthermore, earlier detection allows for more aggressive management of phosphate and calcium intake, potentially slowing arterial hardening.

Conclusion

Managing mineral bone disease is vital for improving outcomes in patients entering dialysis. While corrected calcium is commonly used, ionized calcium appears to offer a more stable relationship with coronary artery calcification. Implementing routine ionized calcium checks could refine cardiovascular risk assessment at the very start of the dialysis journey. Eventually, this shift in diagnostic focus might lead to better tailored therapies for end-stage renal disease patients.

Frequently Asked Questions

Why is ionized calcium preferred over corrected calcium in dialysis patients?

Ionized calcium represents the physiologically active form of the mineral. In dialysis patients, albumin levels and pH fluctuations often make calculation formulas like Payne's less accurate, leading to overestimation of calcium status.

What does a high coronary artery calcium score (CACS) signify?

A high CACS, specifically over 400, indicates significant atherosclerotic plaque burden. For patients starting hemodialysis, it serves as a strong predictor of future cardiovascular events and mortality.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice or a professional relationship. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

Ito H et al. Association of Serum Calcium Levels With Coronary Artery Calcification in Patients at the Initiation of Hemodialysis. Hemodial Int. 2026 Mar 06. doi: 10.1111/hdi.70064. PMID: 41789532.

KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease–Mineral and Bone Disorder (CKD-MBD). Kidney Int Suppl. 2017;7(1):1-59.

Sharma A et al. Vascular Calcification in Chronic Kidney Disease Patients on Hemodialysis: Prevalence and Correlation. Indian Journal of Clinical Practice. 2023;34(1):16-21.