Considerable disagreement exists among various specialists on how to treat secondary hyperparathyroidism (SHPT), according to the results of a new Dutch survey.
The survey consisted of 8 case vignettes of patients with SHPT on hemodialysis and suitable candidates for kidney transplantation. Each case varied by 1 important variable: age (40 vs 65 years), parathyroid hormone (PTH; 40 vs 90 pmol/L), and serum calcium level (2.25 vs 2.8 mmol/L). Respondents chose among active vitamin D, calcimimetics, or subtotal parathyroidectomy (PTx) for treatment.
A total of 115 specialists responded to the survey, including nephrologists, endocrinologists, and surgeons. In 6 out of 8 cases, more than a third of respondents disagreed on the best course of treatment. Elevated serum calcium level was the top reason for respondents to abandon conservative treatment in favor of subtotal PTx, Jaimie Zhang, MD-PhD student at Leiden University Medical Center in Leiden, The Netherlands, and colleagues reported in BMC Nephrology. High serum calcium of 2.8 mmol/L was significantly associated with 93- and 31-fold increased odds of opting for subtotal PTx and calcimimetics, respectively, rather than vitamin D therapy. High PTH of 90 pmol/L was significantly associated with 22- and 8-fold increased odds of choosing subtotal PTx and calcimimetics, respectively.
By specialty, endocrinologists had significant 2.6-fold increased odds of choosing subtotal PTx compared with nephrologists. Both surgeons and endocrinologists had 45% decreased odds of choosing calcimimetics compared with nephrologists.
By volume of SHPT patients, clinicians with more experience had 55% decreased odds of opting for subtotal PTx and 29% increased odds of calcimimetics.
Other factors important in the decision-making process included response to vitamin D or calcimimetics, the identification of other causes of hypercalcemia, PTH stability, transplant eligibility, and the presence of hypercalcemia complications.
“Since consensus regarding the best treatment for [renal hyperparathyroidism] is lacking, shared decision making is of the utmost importance,” according to the investigators. “In order to properly counsel patients on this complex topic, physicians should have a thorough understanding of the pathophysiology of [renal hyperparathyroidism] even in the light of awaiting a kidney transplant and the pros of cons of each treatment modality.”
The team supports conducting a trial comparing subtotal PTx to medical treatment.
Zhang JLH, Appelman-Dijkstra NM, Fu EL, Rotmans JI, Schepers A. Practice variation in the treatment of patients with renal hyperparathyroidism: a survey-based study in the Netherlands. BMC Nephrol 22(1):150. doi:10.1186/s12882-021-02361-7