Introduction
Inflammatory bowel diseases (IBD), encompassing ulcerative colitis (UC) and Crohn’s disease (CD), are associated with an increased risk of metabolic bone diseases (MBD), primarily osteopenia and osteoporosis; however, the risk at IBD diagnosis is currently unknown.
Aims & Methods
The aim of the current study was to evaluate a screening strategy for MBD in which all patients with newly diagnosed IBD are offered a Dual-energy X-ray absorptiometry (DXA) scan. Secondly, we aimed to identify risk factors for development of MBD.
All adult patients with newly diagnosed IBD within a catchment area corresponding to ~20% of the Danish population have since May 2021 been enrolled in an ongoing prospective population-based inception cohort, IBD Prognosis Study. Herein, all participants were, as part of the initial work-up, invited to a DXA scan at IBD diagnosis. A T-score< −2.5 standard deviations (SD) was diagnostic for osteoporosis, while a T-score between –1 and –2.5 defined osteopenia. Multivariate analyses adjusted findings for age, gender, and medication differences.
Results
As of April 15th, 2023, a total of 316 newly diagnosed patients with IBD (UC: 178, CD: 117, IBD unclassified (IBDU): 21) received a DXA scan within 90 days (interquartile range (IQR) 51-139 days). Baseline characteristics of the population were similar to those previously described for newly diagnosed IBD.
In total, 48 (27.0%, females (F): 26.3%, males (M): 27.7%) and 17 (9.6%, F: 13.7%, M: 4.8%) patients with UC were found to have osteopenia and osteoporosis, respectively. The corresponding numbers for CD were 23 (19.7%, F: 15.3%, M: 24.1%) and nine (7.7%, F: 6.8%, M: 8.6%).
Subgroup analysis showed a high occurrence of osteopenia in both UC and CD regardless of age group (Table 1). Further, no difference between UC and CD was observed in terms of the risk of osteopenia (adjusted odds ratio (aOR)=1.86 (95% confidence interval (CI) 0.99-3.60) or osteoporosis (OR=1.42 (95% CI 0.53-4.08)).
Further, low albumin level (<36 g/L) was the only factor associated with the risk of osteopenia in patients with UC (aOR=2.57 (95% CI 1.05-6.53). In patients with CD, no risk factors were identified for development of osteopenia, although a trend was seen with high age (aOR=4.28 (95% CI 0.99-20.23). However, the risk of osteoporosis was independently associated with age higher than 65 years in both UC (aOR=13.4 (95% CI 3.78-51.36)) and CD (aOR=6.39 (95% CI 1.09-35.47)), while female gender was not relevant (UC: aOR=2.63 (95% CI 0.75-10.98), CD: (aOR=0.47 (95% CI 0.08-2.20)).
Finally, in both UC and CD, the risk of these MBD was not associated with IBD phenotype, medications, or patient-reported or endoscopic severity.
Table 2: Prevalence of osteopenia and osteoporosis in different age groups in patients with newly diagnoses patients with inflammatory bowel diseases
| Osteopenia | Osteoporosis |
| Age group (years) | Ulcerative colitis | Crohn's disease | IBD unclassified | Ulcerative colitis | Crohn's disease | IBD unclassified |
| 18-30 | 9/55 (16.4) | 6/50 (12.0) | 1/10 (10.0) | 0/55 (0) | 2/50 (4.0) | 0/10 (0) |
| 31-40 | 5/27 (18.5) | 3/24 (12.5) | 0/4 (0) | 0/27 (0) | 2/24 (8.3) | 0/4 (0) |
| 41-50 | 9/26 (34.6) | 3/9 (33.3) | 1/2 (50.0) | 3/26 (11.5) | 1/9 (11.1) | 0/2 (0) |
| 51-60 | 16/38 (42.1) | 3/14 (21.4) | 2/2 (100.0) | 4/38 (10.5) | 1/14 (7.1) | 0/2 (0) |
| 61-70 | 4/17 (23.5) | 5/13 38.5) | 1/2 (50.0) | 7/17 (41.2) | 2/13 (15.4) | 0/2 (0) |
| >70 | 5/15 (33.3) | 3/7 (42.9) | 0/1 (0) | 3/15 (20.0) | 1/7 (14.3) | 1/1 (100.0) |
| Total | 48/178 (27.0) | 23/117 (19.7) | 5/21 (23.8) | 17/178 (9.6) | 9/178 (5.1) | 1/21 (4.8) |
Conclusion
To our knowledge, the current study is the first evaluation of DXA scans as a screening tool for patients with newly diagnosed IBD in a population-based setting. We found a high incidence of osteopenia affecting every fourth patient at IBD diagnosis. These findings are concerning given the high risk of repeated need for systemic steroids in this patient population.
Disclosure
Mohamed Attauabi: None
Gorm Roager Madsen: None
Flemming Bendtsen: Tillotts, Ferring
Klaus Theede: Ferring, Janssen, Takeda, Pfizer and Tillotts
Jakob Benedict Seidelin: has received research grants from Takeda, Janssen, the Danish Research Council, and the Capital Region Denmark, and is national coordinator of studies from AbbVie, Arena Pharmaceuticals, Ely Lilly, and Boehringer Ingelheim.
Johan Burisch: reports grants and personal fees from AbbVie, grants and personal fees from Janssen-Cilag, personal fees from Celgene, grants and personal fees from MSD, personal fees from Pfizer, grants and personal fees from Takeda, grants and personal fees from Tillots Pharma, personal fees from Samsung Bioepis, grants and personal fees from Bristol Myers Squibb, grants from Novo Nordisk, personal fees from Pharmacosmos, personal fees from Ferring, personal fees from Galapagos, outside the submitted work.