Association of Parathyroidectomy With 5-Year Clinically Significant Kidney Stone Events in Patients With Primary Hyperparathyroidism.

OBJECTIVE: Patients with primary hyperparathyroidism (PHPT) are at increased risk of kidney stones. Guidelines recommend parathyroidectomy in patients with PHPT with a history of stone disease. This study aimed to compare the 5-year incidence of clinically significant kidney stone events in patients with PHPT treated with parathyroidectomy versus nonoperative management. METHODS: We performed a longitudinal cohort study of patients with PHPT in a national commercial insurance claims database (2006-2019). Propensity score inverse probability weighting-adjusted multivariable regression models were calculated. RESULTS: We identified 7623 patients aged ≥35 years old with continuous enrollment >1 year before and >5 years after PHPT diagnosis. A total of 2933 patients (38.5%) were treated with parathyroidectomy. The cohort had a mean age of 66.5 years, 5953 (78.1%) were female, and 5520 (72.4%) were White. Over 5 years, the unadjusted incidence of ≥1 kidney stone event was higher in patients who were managed with parathyroidectomy compared with those who were managed nonoperatively overall (5.4% vs 4.1%, respectively) and among those with a history of kidney stones at PHPT diagnosis (17.9% vs 16.4%, respectively). On multivariable analysis, parathyroidectomy was associated with no statistically significant difference in the odds of a 5-year kidney stone event among patients with a history of kidney stones (odds ratio, 1.03; 95% CI, 0.71-1.50) or those without a history of kidney stones (odds ratio, 1.16; 95% CI, 0.84-1.60). CONCLUSION: Based on this claim analysis, there was no difference in the odds of 5-year kidney stone events in patients with PHPT who were treated with parathyroidectomy versus nonoperative management. Time horizon for benefit should be considered when making treatment decisions for PHPT based on the risk of kidney stone events.

Risk of Permanent Hypoparathyroidism Requiring Calcitriol Therapy in a Population-Based Cohort of Adults Older Than 65 Undergoing Total Thyroidectomy for Graves' Disease.

Objective: Total thyroidectomy for Graves' disease (GD) is associated with rapid treatment of hyperthyroidism and low recurrence rates. However, it carries the risk of surgical complications including permanent hypoparathyroidism, which contributes to long-term impaired quality of life. The objective of this study was to determine the incidence of permanent hypoparathyroidism requiring calcitriol therapy among a population-based cohort of older adults undergoing total thyroidectomy for GD in the United States. Methods: We performed a population-based cohort study using 100% Medicare claims from beneficiaries older than 65 years with GD who underwent total thyroidectomy from 2007 to 2017. We required continuous enrollment in Medicare Parts A, B, and D for 12 months before and after surgery to ensure access to comprehensive claims data. Patients were excluded if they had a preoperative diagnosis of thyroid cancer or were on long-term preoperative calcitriol. Our primary outcome was permanent hypoparathyroidism, which was identified based on persistent use of calcitriol between 6 and 12 months following thyroidectomy. We used multivariable logistic regression to identify characteristics associated with permanent hypoparathyroidism, including patient age, sex, race/ethnicity, neighborhood disadvantage, Charlson-Deyo Comorbidity Index, urban or rural residence, and frailty. Results: We identified 4650 patients who underwent total thyroidectomy for GD during the study period and met the inclusion criteria (mean age = 72.8 years [standard deviation = 5.5], 86% female, and 79% white). Among this surgical cohort, 104 (2.2% [95% confidence interval, CI = 1.8-2.7%]) patients developed permanent hypoparathyroidism requiring calcitriol therapy. Patients who developed permanent hypoparathyroidism were on average older (mean age 74.1 vs. 72.8 years) than those who did not develop permanent hypoparathyroidism (p = 0.04). On multivariable regression, older age was the only patient characteristic associated with permanent hypoparathyroidism (odds ratio age ≥76 years = 1.68 [CI = 1.13-2.51] compared with age 66-75 years). Conclusions: The risk of permanent hypoparathyroidism requiring calcitriol therapy among this national, U.S. population-based cohort of older adults with GD treated with total thyroidectomy was low, even when considering operations performed by a heterogeneous group of surgeons. These findings suggest that the risk of hypoparathyroidism should not be a deterrent to operative management for GD in older adults who are appropriate surgical candidates.

Evolving Understanding of the Epidemiology of Thyroid Cancer.

The incidence of thyroid cancer worldwide has increased significantly over the past 3 decades, due predominantly to an increase in papillary thyroid cancer. Although most of these cancers are small and localized, population-based studies have documented a significant increase in thyroid cancers of all sizes and stages, in addition to incidence-based mortality for papillary thyroid cancer. This suggests that the increasing incidence of thyroid cancer is due in large part to increasing surveillance and overdiagnosis, but that there also appears to be a true increase in new cases of thyroid cancer.