Background The impact of comorbidity on the course and results of RA treatment isn't investigated enough.
Methods 402 RA patients (pts) (50.0% with early RA, including 12.4% pts with very early RA) were studied. Mean age at inclusion was 49.6±0.58 yrs, disease duration – 52.3±3.15 month. 84.1% of the pts were women; 63.2% were positive for rheumatoid factor and 75.2% - for antibodies against cyclic citrullinated peptides. 175 pts had extra-articular manifestations (EAM): mostly rheumatoid nodules (22.1%), lymphadenopathy (13.3%) and weight loss or fever (10.1%), less frequently - Sjögren's syndrome, vasculitis, eye disease, serositis. Pts were treated with methotrexate (mean dose – 11.6±0.29 mg/w, n=157), leflunomide (19.2±0.28 mg/d, n=95), sulfasalazine (2 g/d, n=76) or combined basic therapy (n=74). Effectiveness outcomes were evaluated after 2 yrs of treatment by ΔDAS28 and modified Sharp-van der Heijde score (ΔSHS).
Results Comorbidity was observed in 58.7% RA pts, 25.0% of them had several comorbid conditions. The following most common comorbidities were recorded in pts with RA: arterial hypertension (AH) (22.5% of comorbidities), thyroid disease (11.9%), osteoarthritis (9.17%), chronic pyelonephritis (5.96%), diabetes mellitus (5.50%), peptic ulcer disease (5.05%), liver pathology (5.05%).
After 2 years clinical response to the treatment was significantly less in pts with comorbidity versus pts without comorbidity (ΔDAS28 2.12±0.13 vs 2.63±0.17, p<0.05), while a degree of radiological progression was only slightly higher (ΔSHS 11.7±1.20 vs 10.0±1.39, p>0.05).
The impact of the most common comorbidities in RA (AH and thyroid disease) on clinical and radiological response to treatment was assessed. Our results suggests that DMARDs efficiency doesn't depend on AH presence (ΔDAS28/ΔSHS – 2.0±0.19/9.05±1.55 vs 2.38±0.17/10.0±1.39 in pts with and without comorbidity respectively). However, in pts with thyroid disorders clinical response to treatment was significantly lower (ΔDAS28 – 1.57 ± 0.29) versus pts without comorbid diseases (2.38 ± 0.17, p<0.05), radiological progression in the compared groups did not differ significantly (ΔSHS – 11.5±2.77 vs 10.0±1.39).
To study the possible mutual aggravating influence of comorbidity and EAM of RA the effectiveness of DMARDs in the relevant subgroups was analyzed: in pts with comorbidity and EAM (n=94) or without EAM (n=142), pts without comorbidity, but with EAM (n=68) or without EAM (n=98). The clinical response in pts without comorbidity and EAM of RA was better (ΔDAS28 2.52±0.20) then in pts with comorbidity and with or without EAM (2.01±0.21 and 1.87±0.17 respectively, p<0.05). The lowest rate of radiographic progression (ΔSHS 8.85±1.13) in pts without comorbidity and EAM was observed (comparing 12.1±1.12 in pts with comorbidity and EAM, p<0.05).
Conclusions 1. Comorbidity in more than half of Ukrainian pts with RA is observed, mostly arterial hypertension and thyroid disease.
2. The presence of comorbidity in pts with RA is associated with a worse clinical efficacy of DMARDs and the trend to greater radiological progression of RA.
3. Pts without comorbidity and EAM of RA have the best clinical response to non-biological DMARDs treatment (significantly better then pts with comorbidity, without EAM) and the lowest degree of radiological progression (vs pts with comorbidity and EAM).
Disclosure of Interest None declared