The change of bone mineral density in patients with inflammatory bowel disease

There is limited data regarding the impact of treatment for IBD on the BMD status. Therefore, this study aimed to identify the change of BMD in the patients with IBD after treatment including 5-aminosalicylic acid, thiopurine, and anti-TNF agents. The cases were retrieved from 442 patients who were diagnosed with IBD in a single university hospital. Of those, 119 patients (CD 84, UC 35) had the follow-up BMD with at least 1-year interval. The associations between BMD, BMI and disease activity parameters including CDAI, Mayo-score, haemoglobin (Hb), c-reactive protein(CRP), serum albumin were evaluated as Pearson correlation analysis and partial correlation; BMD was measured as Z- score and low BMD was defined as less than −1. In enrolled 84 patients with inactive CD, the baseline mean of BMD Z score at the lumbar spine and femur neck were −0.44 ± 1.36, −0.13 ± 1.28; the follow-up mean of BMD Z score at the lumbar spine and femur neck were −0.47 ± 1.21 (p = 0.512), −0.18 ± 1.17 (p = 0.304). In enrolled 35 patients with inactive UC, the baseline mean of BMD Z score were −0.20 ± 1.04, −0.11 ± 1.06; the follow-up mean of BMD Z score at the lumbar spine and femur neck were −0.26 ± 1.05 (p = 0.145), −0.08 ± 1.06 (p = 0.633). The proportion of low BMD patients of CD and UC at the baseline were 30(35.7%), 11(30.6%); the number of low BMD patients with CD and UC at the disease controlled-status were 31(36.9%, p = 0.873), 9(25%, p = 0.599), respectively. Only in the low BMD group of CD, the BMD of femur neck was correlated with BMI, Hb, CRP, and albumin. (0.517: p = 0.003, 0.423: p = 0.02, −0.394: p = 0.031, 0.378: p = 0.039). However, there was no correlation with disease activity parameter and BMD status in partial correlation, using BMI as control variable. There is no correlation with improvement of disease and BMD status after treatment in patients with IBD. However, in low BMD group of CD, treatment itself could improve the status of BMD of femur neck.