Objectives:
Rheumatoid arthritis (RA) is one of the most common systemic inflammatory diseases, but its etiology is still not fully known. The aim of this preliminary study was to assess what particular comorbidities are involved in the progression of RA and determine the influence that the aforementioned diseases have on each other.

Material and methods:
Forty patients with diagnosed RA according to EULAR/ACR criteria from 2010 were included in the study. The majority of the group was female (n = 35; 87.5%). Patients were tested using routine laboratory and imaging methods allowing diagnosis and assessment of disease activity. Dual energy X-ray absorptiometry was also evaluated for mineral density. The activity of the disease was assessed using the disease activity score DAS28 (ESR) and SDAI (Simplified Disease Activity Index).

Results:
Among studied patients, based on the DAS28 index, 9 patients were in the remission phase (22.5%) and 12 (30%) had high disease activity. Increased values ​​of CRP were observed in the majority of patients (65%). The group analysis demonstrated the most common comorbidities in patients with RA, as follows: hypertension (n = 14; 35%) and osteoporosis or osteopenia (n = 13; 32.6%).

Conclusions:
Patients with rheumatoid arthritis (RA) are more susceptible to developing hypertension and osteoporosis. We did not observe a significant association between other comorbidities and activity of RA. The next study will assess a larger number of patients.