Primary hyperparathyroidism and celiac disease: A population-based cohort study

Abstract

Context: Celiac disease (CD) has been linked to several endocrine disorders, including type 1 diabetes and thyroid disorders, but little is known regarding its association to primary hyperparathyroidism (PHPT). Objective: The aim of the study was to examine the risk of PHPT in patients with CD. Design and Setting: We conducted a two-group exposure-matched nonconcurrent cohort study in Sweden. A Cox regression model estimated hazard ratios (HR) for PHPT. Participants: We identified 17,121 adult patients with CD who were diagnosed through biopsy reports (Marsh 3, villous atrophy) from all 28 pathology departments in Sweden. Biopsies were performed in 1969-2008, and biopsy report data were collected in 2006-2008. Statistics Sweden then identified 85,166 reference individuals matched with the CD patients for age, sex, calendar period, and county. Main Outcome Measure: PHPT was measured according to the Swedish national registers on inpatient care, outpatient care, day surgery, and cancer. Results: During follow-up, 68 patients with CD and 172 reference individuals developed PHPT (HR = 1.91; 95% confidence interval = 1.44-2.52). The absolute risk of PHPT was 42/100,000 person-years with an excess risk of 20/100,000 person-years. The risk increase for PHPT only occurred in the first 5 yr of follow-up; after that, HR were close to 1 (HR = 1.07; 95% confidence interval = 0.70-1.66). Conclusions: CD patients are at increased risk of PHPT, but the absolute risk is small, and the excess risk disappeared after more than 5 yr of follow-up. Copyright © 2012 by The Endocrine Society.