Celiac.com 05/07/2012 - People with celiac disease face a higher risk of developing primary hyperparathyroidism (PHPT) in the early years after their celiac disease is diagnosed, according to a new report from Sweden. The report appears in the The Journal of Clinical Endocrinology & Metabolism.
At least one other study has suggested an association between celiac disease and primary hyperparathyroidism.
For their study, Dr. Jonas F. Ludvigsson from Orebro University Hospital and colleagues examined the risk of PHPT among 17,121 patients with biopsy-verified celiac disease. They found that patients with celiac disease faced a 1.91-fold increased risk of PHPT compared to 85,166 matched controls.
Ignoring the first year, due to a risk of ascertainment bias, the team found that the risk level for PHPT increased 3.29-fold through 60 months, and disappeared after that period.
The decrease in risk level over time may be due to the beneficial effect of the gluten-free diet, the team noted. For every per 100,000 person-years at risk, the absolute risk level from one to five years of follow-up was 61 cases in patient, compared with just 22 cases in controls. The overall risk level was even greater, by 2.53 times, when the outcome was restricted to PHPT with an adenoma diagnosis in the National Cancer Registry.
A review of the data show that the increased risk of PHPT persisted after restricting the analysis to 1987 or later, which post-date changes in ICD coding. The risk for PHPT was slightly higher for women diagnosed with celiac disease after menopause than for women diagnosed earlier in life.
Their study does not "provide any insight into the nature of the association between celiac disease and PHPT," the authors admit. They are unsure whether the association is causal or whether celiac disease and PHPT might be tied another unidentified condition.
Because most patients with untreated celiac disease have vitamin D and calcium deficiencies, the team expected to find a "constellation of celiac disease and elevated parathyroid hormone levels," but that they did not expect to see a connection between celiac disease with hypercalcemia and PHPT.
The team calls for future studies to focus on thoroughly investigating the connection, so that researchers can understand all possible aspects of the link between these two conditions.