Surgery No Help for the Kidneys in Older Folks With Primary Hyperparathyroidism

Parathyroidectomy within the first year after a primary hyperparathyroidism (PHPT) diagnosis wasn't much help for preserving kidney function in older adults, an observational study suggested.

Looking at over 43,000 patients with PHPT, there was no difference in the risk for estimated glomerular filtration rate (eGFR) decline between patients managed surgically with early parathyroidectomy compared with those who received nonoperative management (HR 0.98, 95% CI 0.82-1.16), reported Carolyn D. Seib, MD, MAS, of Stanford University in California, and colleagues in the Annals of Internal Medicine.

At 5 years, the weighted cumulative incidence of eGFR decline was 5.1% in both those managed with parathyroidectomy and those managed nonoperatively. At 10 years, the weighted cumulative incidence was 10.8% and 12%, respectively.

Over the median 4.9-year follow-up, 6.7% of the cohort experienced at least a 50% decline in pretreatment eGFR.

When Seib's group took a closer look at these outcomes stratified by age, significant differences started to emerge. They found that in patients younger than 60, parathyroidectomy actually was significantly associated with a 25% reduced risk for an eGFR decline of at least 50% (HR 0.75, 95% CI 0.59-0.93). On the other hand, patients ages 60 and older didn't see this benefit (HR 1.08, 95% CI 0.87-1.34).

Neither treatment strategy was favored when patients were stratified by baseline eGFR.

"Parathyroidectomy, which is a low-risk, outpatient surgery for most patients, is the only treatment for primary hyperparathyroidism and is associated with many long-term benefits," Seib told MedPage Today. For these reasons, this treatment option should be discussed with all patients at the time of PHPT diagnosis, with consideration of the individual patient's surgical risk and potential benefits over their anticipated lifespan.

"Our study shows that the benefits of parathyroidectomy related to kidney function are most relevant to patients who are younger than 60 years of age, which supports operative management in this group to prevent chronic kidney disease," she explained. "However, for older patients considering parathyroidectomy, benefits related to kidney function should not be a primary consideration. In these older patients, the reduced risk of fractures and improved quality of life that have been documented in prior studies are more relevant when weighing the risks and benefits of surgery versus observation."

Seib advised clinicians to bear in mind that preservation of kidney function is only one clinical outcome to consider when making treatment decisions for primary hyperparathyroidism.

"It is important that physicians also discuss with their patients the potential long-term benefits of parathyroidectomy related to fractures, kidney stones, cardiovascular disease, and quality of life, in addition to the need for lifelong surveillance if surgery is declined, weighing these against an individual patient's risk of surgery," she added.

Current clinical practice guidelines recommend parathyroidectomy as one method to prevent chronic kidney disease (CKD) progression in PHPT patients -- a population that has a higher risk for CKD -- especially for patients under 50. Parathyroidectomy is usually recommended for those with an eGFR less than 60 mL/min/1.73 m².

Patients with new biochemical diagnoses of PHPT -- defined as an elevated parathyroid hormone level (over 65 ng/mL) within 6 months after an elevated serum calcium level (over 10.2 mg/dL) -- were pulled from the Veterans Health Administration between 2000 and 2019. Those with stage 5 CKD were excluded, as were those with an eGFR below 30 mL/min/1.73 m² for the year prior to PHPT diagnosis.

Of the cohort, 87.5% were men, average age was 67, 67.5% were white, and 22% were Black. At baseline, mean eGFR was 71.8 mL/min/1.73 m² and mean parathyroid hormone level was 115.1 ng/mL.

In the first year after PHPT diagnosis, 8.7% were treated with parathyroidectomy, while 91.3% were managed nonoperatively. Parathyroidectomy patients tended to be younger, white, and have fewer comorbidities.

"We hope that this paper, in addition to our other recent publications showing skeletal and cardiovascular outcomes following parathyroidectomy, will help patients and their doctors make informed decisions about how to manage primary hyperparathyroidism," Seib said.

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