Context
Kidney complications may be considerably higher in patients with chronic hypoparathyroidism (hypoPT) treated with activated vitamin D and calcium supplementation.
Objective
To investigate the risk of chronic kidney disease (CKD), urolithiasis and hospitalization in patients with chronic hypoPT.
Design
The Swedish National Patient Register, the Swedish Prescribed Drug Register and the Total Population Register, 1997–2018.
Setting
Population-based cohort study in Sweden.
Patients
National registries were used to identify patients with chronic hypoPT and controls matched by sex, age, and county of residence.
Main Outcome Measures
Incidence rates of hospitalization; time to CKD and urolithiasis diagnosis.
Results
A total of 1,562 patients with chronic hypoPT without preexisting CKD and 15,620 controls were included. The risk of developing CKD was higher in patients with chronic hypoPT compared with controls (hazard ratio [HR] 4.45, 95% confidence interval [CI] 3.66–5.41). In people without prior urolithiasis (n=1,810 chronic hypoPT and n=18,100 controls), the risk of developing urolithiasis was higher in patients with chronic hypoPT (HR 3.55, 95% CI 2.84–4.44) compared with controls. Patients with chronic hypoPT had higher incidence rates for all-cause hospitalization (49.59, 95% CI 48.50–50.70, per 100 person-years vs. 28.43, 95% CI 28.15–28.71, respectively) and for CKD (3.46, 95% CI 3.18–3.76, per 100 person-years vs. 0.72, 95% CI 0.68–0.77, respectively), compared to controls. Men with hypoPT appear to have a higher risk of CKD than women.
Conclusions
Patients with chronic hypoPT had an increased risk of CKD, urolithiasis, and hospitalization compared to controls.