Corticosteroid-Induced Osteoporosis and Osteopenia in Inflammatory Bowel Disease

Abstract

Purpose: Patients with inflammatory bowel disease are highly susceptible to develop osteoporosis or osteopenia, a condition that is more commonly occurred in patients with corticosteroid use. The aim of the present study was to determine the prevalenceof low BMD in corticosteroid ever-users and related risk factors among Iranian IBD patients. Methods: Totally, 94 corticosteroid ever-user IBD patients with a mean duration of 11.7 ± 17.7 months corticosteroid use, were included. Bone mineral density was measured at lumbar spine (L1-L4), femoral neck, and radius 33% by dual energy x-ray absorptiometry (DXA). Initial data were gathered by a questionnaire and blood samples were obtained to measure biochemical markers. Student t test, chi square, ANOVA, and Tukey HSD were applied, when appropriate. To find predictive variables for BMD, step wise regression analysis was performed. Results: The study population included 34 males and 60 females with the mean age of 38.4 ± 13.2 years. Of 94 patients, 67 had ulcerative colitis (UC) and 27 had Crohn's disease (CD). Seven patients (7.4%) had osteoporosis and 35 (37.2%) were osteopenic. Osteoporosis and osteopenia were most pronounced at lumbar spine both in UC and CD patients. Lumbar spine t score was inversely correlated with age and 25-OH vitamin D level (r =−0.37, p < 0.0001, r =−0.29, p < 0.007, respectively). Femoral neck t score was inversely correlated with age (r =−0.27, p < 0.01). Low BMD was associated with higher prevalence of pathologic fracture (p < 0.04). Osteoporotic patients had lower level of vitamin D and older age when compared with both osteopenic and normal subjects (p < 0.05 for all differences). Step wise regression analysis revealed that lumbar spine T-score could be predicted by age (p < 0.0001), whereas femoral neck T-score was predicted by age (p < 0.0001), BMI (p < 0.01) and history of smoking (p < 0.02). Radius 33% t-score was predicted by age (p < 0.0001) and BMI (p < 0.01). Conclusions: Corticosteroid use is associated with lower BMD and higher prevalence pathologic fracture among Iranian patients with IBD. Patients' age is the most important factor correlating with lumbar spine and femoral neck density. Meanwhile, lumbar spine T-score could be predicted by age and femoral neck by age, BMI and history of smoking.