AB0913 PREDICTING PATIENTS AT RISK OF FRAGILITY FRACTURE WITH NORMAL BONE MINERAL DENSITY: AN OBSERVATIONAL STUDY
Authors: C. Saleh, M. Bukhari, S. M. Bilgrami
Journal: Annals of the Rheumatic Diseases (2020)

Background: There is an increased risk of low-trauma fracture as bone mineral density (BMD) decreases, however a large proportion of these fragility fractures occur in those without osteoporosis or osteopenia. The widely used FRAX tool uses femoral neck (FN) BMD, amongst other parameters, to predict fracture risk. In those with normal BMD, data is lacking on the weight these other parameters hold in predicting future risk. Indeed, FN BMD can be facultative in the estimation of risk when using FRAX. Objectives: To establish predictors of fragility fracture in a patient cohort referred for BMD estimation, subsequently found to have bilateral FN BMD of greater than 1. Methods: A cohort of patients in the North West of England referred between 2004 and 2014 for BMD estimation, with both left and right FN BMD of greater than 1 were identified. Patient parameters identified and analysed included age at scan, gender, BMD at left hip, body mass index (BMI), fat mass, family history of fracture, alcohol history of 3 or more units per day, smoking status, rheumatoid arthritis (RA), and steroid exposure. Patients with fragility fracture were compared with those without fracture. Chi-square test and T-test were applied to categorical and continuous data respectively. Further univariate and multivariate logistic regression models were fitted to determine parameters associated with future fracture risk. Results: 619 patients with bilateral FN BMD of greater than 1 were identified and included in analysis. Mean age at scan was 54 years (SD 11.82) and 542 (87.56%) were female. 92 (14.86%) patients had a fragility fracture. Mean left FN BMD was 1.91 (SD 0.71), and mean right FN BMD was 1.92 (SD 0.68). Results of the univariate analysis are described in Table 1 below. Table 1. Logistic regression analysis of patient parameters with unadjusted and adjusted odds ratios for fragility fracture Predictor Unadjusted odds ratio (95% CI) Odds ratio adjusted for age (95% CI) Odds ratio adjusted for age and gender (95% CI) Age at scan (years) 0.99 (0.98-1.01) - - Gender 1.37 (0.66, 2.84) 1.34 (0.64, 2.80) - BMD at left hip 0.34 (0.03, 4.05) 0.37 (0.03, 4.37) 0.50 (0.03, 7.67) BMI 1.07 (1.03, 1.10) 1.07 (1.03, 1.10) 1.07 (1.03, 1.10) Fat mass 1.00 (1.00, 1.00) 1.00 (1.00, 1.01) 1.00 (1.00, 1.01) Parent fractured hip 0.99 (0.57, 1.70) 0.97 (0.56, 1.68) 0.94 (0.54, 1.64) Alcohol (3 or more units/day) 1.16 (0.47, 2.86) 1.16 (0.47, 2.87) 1.16 (0.47, 2.89) Current smoker 1.40 (0.89, 2.21) 1.40 (0.89, 2.21) 1.42 (0.90, 2.23) Rheumatoid arthritis 0.83 (0.32, 2.19) 0.85 (0.32, 2.24) 0.86 (0.34, 2.27) Steroid exposure 0.53 (0.30, 0.96) 0.53 (0.30, 0.96) 0.54 (0.30, 0.98) Conclusion: Steroid exposure and body composition parameters influence fracture risk in this group pf patients with normal BMD, further work will be done looking at the types of fractures and other parameters in this group of patients. Disclosure of Interests: Christopher Saleh: None declared, Marwan Bukhari Speakers bureau: Bristol-Myers Squib, UCB celltech, Roche/Chugai, Pfizer, Abbvie, Merck, Mennarini, Sanofi-aventis, Eli-Lilly, Janssen, Amgen and Novartis., Syed Mujtaba Bilgrami Speakers bureau: Pfizer