ABSTRACT
Bone loss is an ignored complication in inflammatory bowel diseases. Its underling mechanisms are not fully elucidated. To investigate bone turnover in patients with inflammatory bowel diseases.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. 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. 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