Background Osteoporosis (OP) and related fractures occur in patients with AS. No guidelines exist for treating OP in patients with AS.TNFI are increasingly used for treating AS. If TNFIs are proven to prevent or revert bone loss, use of other treatments of OP can be avoided.
Objectives To study the effect of TNF inhibitors on spine and hip BMD in patients with AS.
Methods Two authors searched MEDLINE, EMBASE & Cochrane databases (inception to Dec 31, 2012), reviewed abstracts, read selected articles in full& extracted data. Discrepancies were resolved by a 3rd author. Studies with minimum 6 months follow up & at least 70% of subjects satisfying Modified New York for AS criteria were included. Spine & hip BMD at 1 & 2 years were the primary outcomes. We excluded case reports & studies on children & adolescents. The quality of studies were assessed by Newcastle–Ottawa Quality Assessment Scale.
Results The 5207 titles retrieved were narrowed down to 7 studies (1 RCT, 3 case control and case studies each) that measured outcomes at 6 months (3 studies, 91% Infliximab (I), 5% Etanercept (E), and 14% Adalimumab (A)),1 year (5 studies,42% I, 31% E and 27% A), 2 years (4 studies,71%I,15% E &14% A) & 3 years(1 study). 76-92% were males. Only 2.6% (n=12) got bisphosphonates. Little data was available on calcium intake, vitamin D intake & fracture incidence. Spine BMD increased with TNFI treatment in all studies. The effect was significant compared to controls (4 studies). The effect was noted as early as 6 months & lasted up to 3 years with continued therapy, except in 1 study (n=19, where the change was similar to those on NSAIDs/bisphosphonates(Table 1). Change in spine BMD at 2 years ranged from 5.8-11%. Hip BMD remained stable/ improved by 1.9-2.3% and 1.8-3.5% at 1 & 2 years, respectively. BMD gain correlated to ESR reduction & baseline mSASSS. On multivariate regression analyses, baseline BMD predicted BMD gain. Syndesmophytes did not influence the response of BMD to TNFIs.
Conclusions Treatment with TNF inhibitors improve spine and hip BMD as early as 6 months. On continued treatment, the improvement lasts up to 3 years.
Disclosure of Interest N. Nigil Haroon Grant/research support from: AMGEN Canada, N. AlGhanim: None Declared, R. Inman Consultant for: AMGEN, PFIZER and VYETH, A. Cheung Grant/research support from: AMGEN and PFIZER, Consultant for: AMGEN