Early parathyroidectomy within 1 year of diagnosis of primary hyperparathyroidism (PHPT) did not reduce the risk of a sustained decline in kidney function, measured by a decline in estimated glomerular filtration rate (eGFR) of at least 50%, compared with observation (no surgery) in adults aged 60 and older.
Early parathyroidectomy was, however, associated with a reduced adjusted risk of this decline in kidney function in patients with newly diagnosed PHPT who were younger than age 60.
The findings, based on data from close to 43,000 veterans, were published online in Annals of Internal Medicine.
“The important takeaway from our study is that for older adults [age 60 or older] with primary hyperparathyroidism, preservation of kidney function should not be a primary consideration when making decisions about whether to undergo parathyroidectomy,” lead author Carolyn D. Seib, MD, told this news organization.
“It is important that physicians also discuss with their patients the potential long-term benefits of parathyroidectomy related to a reduced risk of fractures, kidney stones, and cardiovascular disease, and improved 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,” said Dr. Seib, a surgeon at Palo Alto (Calif.) VA Medical Center.
“However, in patients younger than 60, early parathyroidectomy may prevent progression to chronic kidney disease (CKD) and should be more strongly considered,” she noted.
Parathyroidectomy, she observed, is a low-risk outpatient surgery for most adults.
“Potential complications of surgery include temporary or permanent hoarseness, hypoparathyroidism (low postoperative parathyroid function), bleeding requiring return to the operating room, and complications related to general anesthesia, all of which are rare,” said Dr. Seib.
“Surgery by a high-volume surgeon is associated with a reduced risk of complications, so patients should seek out an experienced parathyroid surgeon,” she emphasized.
Moreover, parathyroidectomy is the only treatment for primary hyperparathyroidism.
Does parathyroidectomy slow loss of kidney function?
Multidisciplinary guidelines recommend parathyroidectomy, at least in part to mitigate the risk for, and effects related to, the progression of CKD in patients with PHPT and an eGFR below 60 mL/min per 1.73 m2, the researchers wrote.
However, whether parathyroidectomy slows the loss of kidney function in adults with PHPT is not clear.
Guidelines also state that “observation for PHPT disease progression can be considered when patients have no obvious end organ damage (i.e., eGFR > 60 mL/min per 1.73 m2, normal bone mineral density, and no history of kidney stones or fractures),” Dr. Seib noted.
To address the evidence gap, the researchers emulated a randomized target trial using observational data.
In this type of study, Dr. Seib explained, “although patients aren’t randomly assigned to a treatment, complex statistical methods are used to adjust for baseline confounders in an attempt to emulate random treatment assignment and account for bias that may affect the timing of when patients receive treatment.”
Using national Veterans Health Administration data, researchers identified 43,697 veterans with a new biochemical diagnosis of PHPT, defined as elevated parathyroid hormone (> 65 ng/mL) within 6 months of an elevated serum calcium level (> 32.55 mmol/L or >10.2 mg/dL), from 2000 to 2019.
Of these patients, 3,804 underwent parathyroidectomy within 1 year of diagnosis of PHPT, and 39,893 did not, and instead, a watchful waiting approach was adopted.
To be included in the analysis, patients had to have an eGFR above 30 mL/min per 1.73 m2 for 12 months before PHPT diagnosis to exclude secondary or tertiary hyperparathyroidism.
The primary outcome was a sustained decline in eGFR of at least 50% from baseline.
In the overall cohort, patients had a mean pretreatment eGFR of 71.8 mL/min per 1.73 m2. The mean age of patients was 67, 88% were men, and 68% were White.
After a median follow-up of 4.9 years, 6.7% of the patients had a decline in eGFR of at least 50%.
The cumulative incidence of this decline in eGFR was 5.1% at 5 years and 10.8% at 10 years in patients who had had early parathyroidectomy compared with 5.1% and 12.0%, respectively, in patients who did not undergo surgery.
In the overall population, the risk of at least a 50% decline in eGFR was similar in the early parathyroidectomy group versus the observation group (adjusted hazard ratio [HR], 0.98, 95% confidence interval [CI], 0.82-1.16).
However, diving deeper showed that parathyroidectomy was associated with a reduced risk of the primary outcome among patients younger than 60 years (adjusted HR, 0.75, 95% CI, 0.59-0.93) but not among those aged 60 or older (adjusted HR, 1.08, 95% CI, 0.87-1.34).
“When participating in shared decision-making for older adults [age 60 and older] with PHPT, clinicians should not consider parathyroidectomy for potential benefits of preservation of kidney function,” the researchers reiterated.
“For younger patients, clinicians should discuss the potential benefit of parathyroidectomy to reduce the risk for CKD and associated complications in adults with PHPT,” they concluded.
The study was funded by the National Institute on Aging. The authors reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.