Widely differing screening and treatment practice for osteoporosis in patients with inflammatory bowel diseases in the Swiss IBD cohort study

Abstract

Low bone mineral density (BMD) and osteoporosis remain frequent problems in patients with inflammatory bowel diseases (IBDs). Several guidelines with nonidentical recommendations exist and there is no general agreement regarding the optimal approach for osteoporosis screening in IBD patients. Clinical practice of osteoporosis screening and treatment remains insufficiently investigated.In the year 2014, a chart review of 877 patients included in the Swiss IBD Cohort study was performed to assess details of osteoporosis diagnostics and treatment. BMD measurements, osteoporosis treatment, and IBD medication were recorded.Our chart review revealed 253 dual-energy x-ray absorptiometry (DXA) scans in 877 IBD patients; osteoporosis was prevalent in 20% of tested patients. We identified widely differing osteoporosis screening rates among centers (11%-62%). A multivariate logistic regression analysis identified predictive factors for screening including steroid usage, long disease duration, and perianal disease; even after correction for all risk factors, the study center remained a strong independent predictor (odds ratio 2.3-21 compared to the center with the lowest screening rate). Treatment rates for patients with osteoporosis were suboptimal (55% for calcium, 65% for vitamin D) at the time of chart review. Similarly, a significant fraction of patients with current steroid medication were not treated with vitamin D or calcium (treatment rates 53% for calcium, 58% for vitamin D). For only 29% of patients with osteoporosis bisphosphonate treatment was started. Treatment rates also differed among centers, generally following screening rates. In patients with longitudinal DXA scans, calcium and vitamin D usage was significantly associated with improvement of BMD over time.Our analysis identified inconsistent usage of osteoporosis screening and underuse of osteoporosis treatment in IBD patients. Increasing awareness of osteoporosis as a significant clinical problem in IBD patients might improve patient care.

Figure 1

Screening for osteoporosis in 6 Swiss IBD Cohort Study centers from inclusion into the study until year 2014. (A) Screening rates per center. In a conservative approach, screening rates were defined as evidence of osteoporosis/osteopenia in the cohort documentation and/or the patient chart. (B) OR for having a DXA scan in various centers (compare Table 3). Multivariate analysis: ^∗∗∗P < .001, ^∗∗P < .01, ^∗P < .05. DXA = dual-energy x-ray absorptiometry, IBD = inflammatory bowel disease, OR = odds ratio.

Figure 2

Fraction of dual-energy x-ray absorptiometry (DXA) scans diagnostic for osteopenia or osteoporosis in 6 Swiss study centers from inclusion into the study until year 2014. Percentage of DXA scans diagnostic for osteoporosis or osteopenia are shown. Rates of positive findings did not differ significantly (Chi-square test).

Figure 3

Osteoporosis treatment. (A) Percentage of patients with osteoporosis treatment at the time of chart review according to results of DXA scans. For the statistical analysis patients with osteoporosis/osteopenia were compared to patients with normal BMD. Fisher exact test: ns, ^∗P < .05, ^∗∗P < .01, ^∗∗∗P < .001. (B) Treatment in patients depending on their history of steroid therapy. For the statistical analysis patients which never received steroids were compared to patients with current or any steroid treatment. No significant differences were found. BMD = bond mineral density, DXA = dual-energy x-ray absorptiometry, ns = not significant.

Figure 4

Improvement of dual-energy x-ray absorptiometry (DXA) results of the lumbar spine upon treatment with vitamin D or calcium. (A) Changes in T scores of the spine over time with and without calcium treatment (R² = .17, P = .004, linear regression analysis). For comparison patients without calcium treatment are shown. (B) Changes in T scores with and without vitamin D treatment (R² = .13, P = .007).