AB1008 Comparison of bone mineral density between rheumatoid arthritis patients and healthy individuals over seven years from the tomorrow study

• Published in: Annals of the rheumatic diseases Vol. 77; no. Suppl 2; p. 1623
• Main Authors: Tada, M., Inui, K., Sugioka, Y., Okano, T., Yamada, Y., Mandai, K., Mamoto, K., Koike, T., Nakamura, H.
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group LTD 01.06.2018
• Subjects: Body weight; Bone density; Bone mineral density; Data processing; Dual energy X-ray absorptiometry; Glucocorticoids; Health risk assessment; Osteoporosis; Patients; Rheumatoid arthritis; Spine (lumbar); Surgery
• ISSN: 0003-4967; 1468-2060
• DOI: 10.1136/annrheumdis-2018-eular.2298

BackgroundDespite advances in treatment, rheumatoid arthritis (RA) remains a key cause of secondary osteoporosis and is also a risk factor for fragility fracture. We have previously reported that bone mineral density (BMD) was lower in patients with RA than in healthy individuals (HI) and examined changes in BMD over 3 years1.ObjectivesTo observe BMD changes over 7 years and identify factors that affect BMD changes in patients with RA.MethodsWe analysed data from the TOMORROW study (UMIN000003876), a prospective cohort for patients with RA and age- and sex-matched HI. BMD was measured at three parts (whole body, lower limb, lumbar spine) using dual-energy X-ray absorptiometry (DXA). We compared the percentage change in BMD (%ΔBMD) at the three parts in RA and HI from 2010 to 2017. Factors affecting%ΔBMD in RA were analysed.ResultsParticipants comprised 172 HI and 119 RA, after excluding those who dropped out (HI, n=21; RA, n=19) or underwent implant surgery (HI, n=12; RA, n=60). Height and weight reduced significantly over 7 years (p<0.001 each) in both groups (table 1). The%ΔBMDs of RA were −2.6% (whole body), −3.6% (lower limb), and 1.8% (lumbar spine), compared to −2.0%, −2.7%, and 0.6%, respectively, for HI. No significant differences in BMD for the whole body or lower limb were seen during 7 years, while BMD of the lumbar spine was significantly increased in both groups (p<0.0001). No significant differences between groups were identified. In patients with RA, DAS28ESR improved significantly over 7 years (p=0.008; table 1) and%ΔBMD of the lumbar spine correlated significantly with cumulative period of treatment for osteoporosis (r=0.341, p<0.001). The cumulative period of osteoporosis treatment was identified as a regulatory factor for increasing BMD of the lumbar spine (odds ratio: 1.36; p=0.003) adjusted by age and sex (table 2). However, cumulative period of biologics, change of glucocorticoid and DAS28ESR were not detected as factors affecting BMD by logistic regression analysis.Abstract AB1008 – Table 1Changes in characteristics over 7 yearsParameterTotal population(n=291)Healthy individuals (n=172)Patients with RA(n=119)P value Age 201056.6±12.757.1±12.355.9±13.30.431Height 2010 (cm)157.3±7.8157.9±7.1156.4±8.70.107Height 2017 (cm)156.1±8.1156.8±7.3155.2±9.10.107Body weight 2010 (kg)56.1±10.056.5±10.355.6±9.70.418Body weight 2017 (kg)55.1±10.455.8±10.754.0±9.90.145DAS28 ESR 2010--3.17±1.27-DAS28 ESR 2017--2.86±1.24-Abstract AB1008 – Table 2Factors associated with increased BMD of the lumbar spine in patients with RAFactorOdds ratio95% CIP value Period of osteoporosis treatment1.361.11–1.660.003Period of biologics1.020.92–1.130.683Change of glucocorticoid1.010.83–1.230.933Change of DAS28ESR1.040.76–1.440.798ConclusionsBMD of the whole body and lower limb tended to decrease slightly over 7 years in both groups. However, BMD of the lumbar spine increased significantly. Continued osteoporosis treatment is important for increasing BMD at the lumbar spine in patients with RA.Reference[1] Use of bisphosphonate might be important to improve bone mineral density in patients with rheumatoid arthritis even under tight control: the TOMORROW study. Rheumatol Int2017;37:999–1005.Disclosure of InterestNone declared