Decrease of trabecular bone score reflects severity of Crohn's disease: results of a case-control study

Osteoporosis and osteopaenia are known chronic complications of inflammatory bowel diseases. The trabecular bone score (TBS) provides an indirect measurement of bone microarchitecture, independent of bone mineral density (BMD).

The study was designed as a case-control study with the aim to assess and compare bone quantity and quality in patients with Crohn's disease (CD). We purposefully excluded postmenopausal women and patients on long-term corticosteroid therapy.

The cohort consisted of 50 CD patients and 25 healthy controls who matched in age, sex, weight, or vitamin D status. There was no significant difference between CD patients versus controls in the mean lumbar BMD of 0.982±0.119 versus 0.989±0.12 g/cm and the mean TBS score of 1.37±0.12 versus 1.38±0.12. We observed significantly lower TBS, but not lumbar BMD, in CD patients with stricturing (B2, 1.36±0.08) or penetrating (B3, 1.32±0.11) disease compared with those with luminal disease (B1, 1.42±0.11; P=0.003 and <0.0001, respectively). We also observed lower mean±SD TBS in patients on versus not on anti-tumour necrosis factor-α therapy: 1.341±0.138 versus 1.396±0.099, respectively. However, the difference between these groups failed to reach statistical significance (P=0.11). No similar finding was seen comparing lumbar BMD in these groups.

For the first time, it was observed that TBS, but not BMD, correlates with the severity of CD. Our results therefore suggest that TBS can potentially help to identify high fracture risk CD patients better than BMD alone.