Prevalence and complications of nonsurgical hypoparathyroidism in Korea: A nationwide cohort study.

OBJECTIVE: The risk of complications of nonsurgical hypoparathyroidism in Asia is unclear. We estimated the prevalence and risk of complications in patients with nonsurgical hypoparathyroidism. METHODS: We performed a retrospective cohort study using a nationwide claims database from 2005 to 2016. Among the entire Korean population, we identified 897 patients diagnosed with nonsurgical hypoparathyroidism during 2005-2015. We selected 210 patients with nonsurgical hypoparathyroidism during 2005-2008 who had no complications at baseline and followed them to 2016. Control subjects (n = 2075) were matched using propensity scores based on age, sex, and comorbid disease with a 1:10 ratio and monitored until 2016. RESULTS: The age-standardized prevalence of nonsurgical hypoparathyroidism was 0.2 cases per 100,000 persons in 2005. During a mean follow-up period of 9.5 years, patients with nonsurgical hypoparathyroidism had a higher risk of cardiovascular disease, especially arrhythmia (hazard ratio [HR], 2.03; 95% confidence interval [CI], 1.11-3.70) and heart failure (HR, 2.43; 95% CI, 1.22-4.83). The risk of vertebral fracture was higher in patients than in controls (HR, 2.27; 95% CI, 1.09-4.72). Patients had a significantly increased risk of renal disease (HR, 2.57; 95% CI, 1.56-4.21), seizure (HR, 5.74; 95% CI, 3.34-9.86), depression and bipolar disease (HR, 1.82; 95% CI, 1.30-2.56), and cataract (HR, 1.90; 95% CI, 1.30-2.79) compared with controls. CONCLUSIONS: The prevalence of nonsurgical hypoparathyroidism was very low in Korea but was associated with a higher risk of incident cardiovascular disease and vertebral fracture as well as known complications including renal disease, seizure, and cataract.