Background Rheumatoid arthritis (RA) is a systemic, autoimmune disease that mainly affects the joints.[1] Furthermore, patients with RA may suffer from different concurrent comorbidities. These comorbidities should be considered when treating RA patients, as they are closely related to treatment response and long-term prognosis.[2] Earlier studies were in favor of increased prevalence of diabetes mellitus (DM) among RA patients; however the association of RA disease characteristic and DM has not previously been evaluated.[3] Considering the prevalence of DM in Denmark (5.7%), patients with RA are at higher risk of DM, possibly due to autoimmunity and RA treatment e.g. steroids.

Objectives To determine the association between clinical characteristics of RA and DM as well as estimate the prevalence of DM among RA patients.

Methods A cross sectional study of the prevalence and association of DM and RA was conducted on all RA patients who had been diagnosed with RA since 1st of January 2010 at the department of Rheumatology. For each patient, data on demographics (age, sex, year of diagnosis), serology test results including rheumatoid factor (RF), anti-cyclic citrullinated peptide antibody (anti-ccp) and antinuclear antibody (ANA) as well as disease activity score in 28 joints (DAS28) at the time of diagnosis and after 4 months (±1–2 months) of treatment were collected in December 2015. To identify patients with concurrent diagnosis of DM, we consequently evaluated all patients' previous medical history, medications and laboratory tests. Chi-square test and t-test were used to compare different variables in patients with/without diabetes.

Results 439 patients were included in this study. Of all included patients 60.14% were female and the mean of age and disease duration were 64.64±15.03 and 2.59±1.66 years respectively. Prevalence of DM was 57/439 (13%). Of 57 patients, 9 patients had hemoglobin A1C ≥48 mmol/mol without receiving antidiabetic medication and 9 patients had been prescribed prednisolone with an average of 6.4±2.4 mg daily. The results of our study revealed that longer RA disease duration is associated with higher prevalence of DM, since patients who were diagnosed before 2012 had higher prevalence of DM in comparison with patients who were diagnosed within 2012 and later (P=0.05). We did not find any association between presence of DM and gender, RF, anti-ccp, ANA as well as ΔDAS28.

Conclusions DM is more prevalent among patients with RA compared to general population (13% versus 5.7%). Routine measurement of hemoglobin A1C, at diagnosis and on a yearly basis, in patients with RA should be taken into consideration leading to earlier diagnose of DM and better overall prognosis.

1. Gabriel SE, Michaud K. Epidemiological studies in incidence, prevalence, mortality, and comorbidity of the rheumatic diseases. Arthritis Research & Therapy. 2009;11:229.

2. Dougados M, Soubrier M, Antunez A, et al. Prevalence of comorbidities in rheumatoid arthritis and evaluation of their monitoring: results of an international, cross-sectional study (COMORA). Ann Rheum Dis. 2014;73:62–8.

3. Jiang P, Li H, Li X. Diabetes mellitus risk factors in rheumatoid arthritis: a systematic review and meta-analysis. Clin Exp Rheumatol. 2015;33:115–21.

Disclosure of Interest None declared