P460. Is it necessary to perform x-ray absorptiometry in young IBD patients to predict the risk of fracture?
K. Lorinczy1, P.L. Lakatos2, Á. Salamon3, A. Nemes3, T. Pere3, Á. Csontos1, B. Fekete1, O. Terjék1, L. Herszényi1, Z. Tulassay1, P. Miheller1, 1Semmelweis University, 2nd Department of Internal Medicine, Budapest, Hungary, 2Semmelweis University, 1nd Department of Internal Medicine, Budapest, Hungary, 3János Balassa Tolna County Hospital, Department of Gastroenterology, Szekszárd, Hungary
Inflammatory bowel disease (IBD) patients have an increased risk of osteoporosis related fractures. Necessity of bone density measurement in IBD patients is not clearly defined, however, the risk of fracture increases among them. Fracture Risk Assessment Tool (FRAX) score computes the 10-years probability of the major osteoporotic fractures and particularly hip fracture. Clinical FRAX (c-FRAX) does not include the bone mineral density (BMD) measurement. We aimed to compare the value the c-FRAX to FRAX enhanced with dual x-ray absorptiometry (DEXA) (bmd-FRAX) in IBD patients.
169 consecutive IBD patients (128 Crohn's disease (CD) and 41 ulcerative colitis (UC); female/male: 88/81) were included into the study. Mean age of the patients was 35.9±11.7 years, 7.6% of them was postmenopausal women. FRAX-scores were calculated with the online tool using a Hungarian algorithm. Bone mineral density measurements were performed by DEXA. Calculations were performed using SPSS statistics 15.0 software.
In patients under 40 the c-FRAX score regarding major osteoporotic fracture risk was significantly higher compared to bmd-FRAX (1.9±1.1 vs. 1.4±0.8, p < 0.01). The same difference was observed computing the probability of hip fractures (c-FRAX: 0.4±0.7 vs. bmd-FRAX: 0.3±0.5; p < 0.05). In a subgroup analysis the fracture risks have not differed in CD vs. UC patients. Major fracture risk c-FRAX and bmd-FRAX were 3.0±3.4% és 2.4±2.7% in CD and 3.4±3.4% and 2.5±2.4% in UC patients (non-significant [NS]). Clinical FRAX and bmd-FRAX showing hip fracture risk were 0.8±1.5% and 0.6±1.4% in CD and 0.8±1.3% and 0.4±0.7% in UC, respectively (NS). We did not observe any correlation between FRAX scores and calcium intake, physical activity, severity, extent and duration of the disease. Subgroup analysis regarding steroid use and body mass index has not been performed due to the FRAX system included in these parameters.
Guidelines regarding IBD associated osteoporosis advise to perform the DEXA measurements in patients with some special risk factors for bone loss. In our study the fracture risk according to FRAX scores completed with DEXA were lower than clinical FRAX – especially in patients younger than 40 years. Our results suggest that DEXA enhanced FRAX may have an advantageous role in preventing over medicating young IBD patients.