Bone Mineral Density and Bone Remodeling in Tunisian Patients with Inflammatory Bowel Disease

Background:A high prevalence of osteopenia and osteoporosis is observed in patients with Inflammatory Bowel Disease (IBD).Objective:The aim of our study was to investigate the prevalence of bone loss, bone remodeling and risk factors in Tunisian patient with IBD.Patients and Methods:The study included 40 patients with IBD and 32 age- and sex-matched healthy controls subjects. All participants underwent bone densitometry by dual energy X-ray absorptiometry at the femoral neck and lumbar spine. Serum levels of 25-hydroxy vitamin D (25(OH)D), parathyroid hormone (PTH), osteocalcin(OC), and urinary degradation products of C-terminal telopeptide of type I collagen (CTXI) were measured in all participants to assess the bone metabolism status.Results:Twelve (30%) patients were normal, 32.5% were osteopenic and 37.5% were osteoporotic. Osteoporosis was more frequent in IBD patients than controls (p=0.0001). Age and inflammation were associated with low bone mineral density (BMD). Mean calcium, phosphorus and alkaline phosphatase levels were similar in both groups. Median 25(OH) D levels were significantly lower in IBD patients compared with controls (p=0.0001). Median urinary CTXI levels were significantly higher in IBD patients compared with healthy controls (p=0.007). No significant differences between IBD patients and controls concerning the median serum OC and PTH levels were found.Conclusion:In our study, there is a high prevalence of low BMD in IBD patients and an increase in bone resorption without a change of bone formation. Low BMI and hypovitaminoses D were identified as risk factors for low BMD.