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.