Background: Osteopenia and osteoporosis are known chronic complications of inflammatory bowel diseases (IBD). It is known that areal bone mineral density (aBMD) does not sufficiently reflect bone strength and quality. The trabecular bone score (TBS) provides an indirect measurement of bone microarchitecture, independent of aBMD.
Methods: The aim was to assess TBS and BMD of lumbar spine (LS) in IBD patients. Furthermore we analyzed the impact of clinical factors on TBS. The cohort consisted of consecutive IBD patients from tertiary IBD centre. Clinical characteristics i.e. age, gender, anthropometry, clinical behaviour, medication were recorded. The BMD was determined by dual-energy X-ray absorptiometry (DXA, Hologic Discovery) at the lumbar spine. TBS was determined by TBS Insight® software (Medimaps, France).
Results: The cohort consisted of 84 IBD patients (53 with Crohn's disease (CD) and 31 with ulcerative colitis (UC)). The mean age was 42.0±14.2 years with the mean disease duration of 11.0±7.0 years. There were 14% (12/84) postmenopausal women, 8 patients (9.5%) were on long term corticosteroids and 21 CD patients had prior major IBD surgery. The percentage of patients with substitution of vitamin D (800IU) and calcium (0.5–1g) was similar between CD and UC (24.5% vs. 29.0%), none of the patients was on anti-porothic treatment. The mean LS BMD of the cohort was 0.964±0.113 g/cm2 and TBS 1.36±0.14. We observed significantly lower mean TBS LS in patients with fistulising CD compared to luminal CD, 1.36±0.09 and 1.47±0.05 (p=0.0039) respectively. No similar finding was observed using BMD. We did not observe any significant impact of clinical characteristics nor medication in UC patients.
Conclusions: We observed that spine TBS can identify quality of bone mineral density in patients with Crohn's disease better than BMD itself. CD patients with severe disease are at higher risk of low bone mineral density.