Regulators of Calcium Homeostasis and Bone Mineral Density in Patients with Crohn's Disease

Abstract

Several papers have reported on vitamin D, parathyroid hormone (PTH), and other regulators of calcium metabolism in patients with Crohn's disease, but results have been conflicting. Bone mineral density (BMD) has been found to be reduced in several papers. A recent study from our laboratory suggested that the expected reduction in BMD disappears when the patients are compared with sex-, age-, and weight-matched healthy controls. The relationship between BMD and regulators of calcium homeostasis is not well established in patients with Crohn's disease. BMD and biochemical regulators of calcium metabolism were measured in 115 unselected patients with Crohn's disease, most of whom were in remission. Vitamin D deficiency (25-OHD < or = 10 pg/ml) was present in 44% of patients. Secondary hyperparathyroidism was present in 2% of unoperated patients and in 18% of patients subjected to bowel operations. 1) Vitamin D deficiency is common in patients with Crohn's disease even when the disease is in remission and regardless of the location of the disease. 2) Secondary hyperparathyroidism is most frequently seen in patients who have undergone intestinal resection(s). 3) PTH correlates with BMD in a large group of unselected patients with Crohn's disease; 25-OHD only correlates with BMD of the forearm.