Unbalanced bone remodeling in Tunisian patients with inflammatory bowel diseases.

BACKGROUND: Bone loss is an ignored complication in inflammatory bowel diseases. Its underling mechanisms are not fully elucidated. OBJECTIVES: To investigate bone turnover in patients with inflammatory bowel diseases. METHODS: The study included 67 patients with inflammatory bowel diseases and 54 age- and sex-matched healthy subjects. Urinary degradation products of C-terminal telopeptide of type I collagen, serum osteocalcin, parathyroid hormone, 25 hydroxy vitamin D and interleukin-6 were assessed. Bone mineral density was measured by dual energy-X-ray absorptiometry and osteoporosis was defined as T score < -2.5 SD. RESULTS: Patients showed significantly higher levels of C-terminal telopeptide of type I collagen and interleukin-6 and lower levels of 25 hydroxy vitamin D. Serum osteocalcin and parathyroid hormone were in normal range. In multivariate analysis, urinary degradation products of C-terminal telopeptide of type I collagen were associated with disease activity (p=0.04) and osteocalcin was associated with parathyroid hormone (p=0.04). Urinary degradation products of Cterminal telopeptide of type I collagen and interleukin-6 were significantly increased in inflammatory bowel disease patients with osteoporosis. No association was found between osteoporosis and serum osteocalcin, parathyroid hormone and 25 hydroxy vitamin D. CONCLUSION: Bone resorption rate is increased and is associated with osteoporosis in inflammatory bowel disease patients. Inflammation, malnutrition, and hypovitaminosis D may contribute to the bone loss.