Risk of Cardiovascular Events, Infections, and Renal Complications in Postsurgical Chronic Hypoparathyroidism: A US Medicare Claims Retrospective Analysis.

Introduction: Hypoparathyroidism (HypoPT) is an endocrine disease caused by insufficient levels of parathyroid hormone and is associated with impaired health-related quality of life. This study assessed the clinical burden among individuals with postsurgical chronic HypoPT in Medicare Fee-For-Service.

Methods: Adults (aged ≥ 18 years) with newly diagnosed HypoPT (N = 1166) were identified from the Medicare 100% Limited Data Set between July 1, 2017, and March 31, 2020. All had a confirmed diagnosis within 6-12 months after index diagnosis and were required to be continuously enrolled for ≥ 6 months pre index and ≥ 12 months post index. A random sample of non-HypoPT controls (N = 11,258) was synthetically assigned an index date of diagnosis to ensure similar baseline and follow-up periods as individuals with postsurgical chronic HypoPT. The two cohorts were compared before and after matching with respect to the risk of cardiovascular (CV) events, renal complications, urinary tract infections (UTIs), upper respiratory tract infections (URTIs), and mortality.

Results: Individuals with postsurgical chronic HypoPT were older than non-HypoPT controls (mean age 69 vs. 64 years), more were female (76% vs. 57%), had higher Charlson Comorbidity Index scores (3.24 vs. 0.73), and a higher prevalence of moderate-to-severe renal disease (28.8% vs. 5.6%), nephrocalcinosis (59.9% vs. 0.6%), and nephrolithiasis (8.3% vs. 1.0%). They also had significantly greater mortality (hazard ratio [HR]  2.75). The incident risks of composite CV events (HR 1.35), renal complications (HR 4.92), UTIs (HR 2.09), and URTIs (HR 1.46) were greater in subcohorts without those conditions prior to index. After matching for baseline characteristics, the elevated risk of renal complications, UTIs, and URTIs remained while there was no difference in the risk of CV events or death between individuals with postsurgical chronic HypoPT and controls.

Conclusion: The substantial clinical burden of postsurgical chronic HypoPT in Medicare patients highlights the treatment gaps associated with current therapy and the need for parathyroid hormone replacement therapies.