The early onset of disease may be a risk factor for decreased bone mineral density in patients with inflammatory bowel disease.

Background/aims: The pathogenesis of bone loss in patients with inflammatory bowel disease (IBD) is complex, multifactorial, and only partly understood. We aimed to examine the extent and risk factors of bone mass reduction and to analyze the impact of early onset of a disease before attaining peak bone mass in IBD patients.

Methods: We compared the risk factors for osteoporosis and BMD at the lumbar spine and the hip bone in IBD patients.

Results: A total of 44 patients with IBD were enrolled. Twenty-one and 23 patients were diagnosed as IBD before and after the age of 30 and designated as group A and group B, respectively. Group A had significant bone mass reduction at the lumbar spine than group B (BMD, 1.01±0.10 vs. 1.14±0.17, p<0.01; T-score, -1.22±0.84 vs. -0.08±1.39, p<0.01; Z-score, -1.11±0.81 vs. -0.03±1.32, p<0.01, respectively). Multivariate analysis showed that patients diagnosed as IBD before the age of 30 had possible risk factor of bone mass reduction (hazard ratio, 3.96; p=0.06).

Conclusions: Bone mass reduction was more severe in patients who were diagnosed with IBD before the age of 30 than in those diagnosed after the age of 30.