REGULATORS OF CALCIUM HOMEOSTASIS AND BONE-MINERAL DENSITY IN PATIENTS WITH CROHNS-DISEASE

Background: Several papers have reported on vitamin D, parathyroid hor mone (PTH), and other regulators of calcium metabolism in patients wit h Crohn's disease, but results have been conflicting. Bone mineral den sity (BMD) has been found to be reduced in several papers. A recent st udy from our laboratory suggested that the expected reduction in BMD d isappears when the patients are compared with sex-, age-, and weight-m atched healthy controls. The relationship between BMD and regulators o f calcium homeostasis is not well established in patients with Crohn's disease. Methods: BMD and biochemical regulators of calcium metabolis m were measured in 115 unselected patients with Crohn's disease, most of whom were in remission. Results: Vitamin D deficiency (25-OHD less than or equal to 10 pg/ml) was present in 44% of patients. Secondary h yperparathyroidism was present in 2% of unoperated patients and in 18% of patients subjected to bowel operations. Conclusions: 1) Vitamin D deficiency is common in patients with Crohn's disease even when the di sease is in remission and regardless of the location of the disease. 2 ) Secondary hyperparathyroidism is most frequently seen in patients wh o have undergone intestinal resection(s). 3) PTH correlates with BMD i n a large group of unselected patients with Crohn's disease; 25-OHD on ly correlates with BMD of the forearm.