P172. Prevalence and predictive factors of low bone mineral density in new onset of inflammatory bowel disease
N. Ben Mustapha1, M. Cheikh2, H. Dabbabi2, M. Serghini2, L. Kallel2, J. Boubaker2, M. Fekih2, A. Filali2, 1La Rabta Hospital, Gastro A Unit, Tunis, Tunisia, 2La Rabta Hospital, Gastro A unit, Tunis, Tunisia
Osteopenia and osteoporosis are frequent in Inflammatory Bowel Disease (IBD) with ileal involvement or treated with steroids. Our aims were to determine the prevalence of low bone mineral density (BMD) at the time of IBD diagnosis, and to identify predictive factors of reduced BMD.
a retrospective study conducted from January 2002 to December 2011 including patients diagnosed with IBD in Gastroenterology A Department at the Rabta University Hospital and in whom BMD was cheked up few days after the diagnosis and before starting any treatment. Data collected were: age, gender, body mass index (BMI), disease activity, disease location. Laboratory findings included serum calcium, phosphate, albumin, hemoglobin, C-reactive protein). BMD was assessed by dual energy x-ray absorptiometry (DEXA) of the lumber spine and femoral neck. Osteopenia was defined as a T-score between −1 and −2 SD, and osteoporosis as a T-score less than −2 SD.
A total of 94 patients (38 men, 56 women) were enrolled. Mean age was 32.81±13.12 years (range 14–72). 73 patients (77.6%) had Crohn's disease (CD) and 21 patients (22.4%) had ulcerative colitis (UC). Mean BMI was 20.53±4.83 kg/m2. Low BMD occurred in 51 (54.2%) patients (38 CD, 13 UC). 32 patients (34%) exhibited osteopenia and 19 patients (20.2%) showed osteoporosis. Mean vertebral T-score was −0.982±1.41 (range −4.1 to 1.7) and BMD in this site was 1.077±0.17 g/cm2 (range 0.674 to 1.380). Mean femoral T-score was −0.326±1.2 (range −3.1 to 2.4) and BMD in this site was 1.001±0.173 g/cm2 (range 0.633 to 1.600). There was a positive correlation between T-score and BMI. Hypoalbuminemia (35 g/l) was found to be a predictive factor of reduced BMD at the moment of IBD diagnosis. However no correlation were found between BMD and the other variables studied (age, gender, severity of the disease, disease location, CRP).
Our results showed that more than half of patients with IBD had a low BMD at the time of diagnosis. Low BMI and hypoalbuminemia were the major factors affecting BMD in these patients. Bone density measurement should be performed in all patients with IBD in an early stage of the disease and not only in patients with ileal involvement or treated with steroids.