Abnormal mineral homeostasis linked to CVD risk in hypoparathyroidism patients

The study showed that adult patients with chronic hypoparathyroidism are likelier to have a CV event if they had a higher percentage of albumin-corrected serum calcium measurements outside the 2.00 to 2.25 mmol/L or any serum phosphate and any calcium-phosphate product measurements over the normal population range.

The cause of chronic hypoparathyroidism is insufficient production of the parathyroid hormone, an essential regulator of serum phosphate and calcium. Active vitamin D and oral calcium supplements are the traditional therapy strategies for these patients. However, it does not impact other physiologic functions of the parathyroid hormone.

The pathophysiological basis for the increased risk of CVD (cardiovascular disease) in patients with chronic hypoparathyroidism is poorly understood. Therefore, Sanjiv Kaul, Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, and colleagues aimed to evaluate the association between levels of serum phosphate, albumin-corrected serum calcium, and calcium-phosphate product with the odds of developing CV (cardiovascular events) in patients with chronic hypoparathyroidism with ≥1 calcitriol prescription.

For this purpose, they conducted a retrospective nested case-control study of patients who developed a CV event and matched controls without an event. Five hundred twenty-eight patients were identified for the albumin-corrected serum calcium analysis and 200 patients for the serum phosphate and calcium-phosphate product analyses using an electronic medical record database. The study's primary outcome was the instance of CV events.

The study revealed the following findings:

• Patients with ≥67% of albumin-corrected serum calcium measurements outside the study-defined 2.00 to 2.25 mmol/L (8.0 to 9.0 mg/100 ml) range had 1.9-fold higher odds of a cardiovascular event than patients having <33% of calcium measurements outside the range.
• Patients with any serum phosphate measurements above 0.81 to 1.45 mmol/L (2.5 to 4.5 mg/100 ml) were at 3.3-fold higher odds, and those with any calcium-phosphate product measurements above 4.40 mmol2/L2 (55 mg2/dL2) were at 4.8-fold higher odds of a cardiovascular event compared with patients with no measurements above these ranges.

"Controlling mineral homeostasis and treatment optimization to achieve clinical goals of calcium and phosphate levels management within ranges described in current guidelines may improve long-term cardiovascular outcomes for chronic hypoparathyroidism patients," the researchers conclude.

Reference:

Kaul S, Ayodele O, Chen K, Cook EE, Swallow E, Rejnmark L, Gosmanova EO. Association of Serum Calcium and Phosphate With Incident Cardiovascular Disease in Patients With Hypoparathyroidism. Am J Cardiol. 2023 May 1;194:60-70. doi: 10.1016/j.amjcard.2023.01.029. Epub 2023 Mar 28. PMID: 36989548.