Background Rheumatoid arthritis (RA) patients with comorbidities are likely to have higher disease activity (DAS28) scores than patients without comorbidities1–3. Diabetes has been recently suggested to associate with higher disease activity in a large group of RA patients4; however, it is still uncertain how baseline diabetes affects RA disease activity and remission percentages in RA5. This is important and information might be used to improve treatment strategies.
Objectives To investigate the effect of having type 2 diabetes on DAS28 scores and RA remission percentages in male and female RA patients during the first year after RA diagnosis.
Methods Data were retrieved from the prospective Nijmegen Early RA cohort. Patients fulfilled the ACR or ACR-EULAR classification criteria. The course of disease activity (DAS28) over the first year after RA diagnosis was the primary outcome. Secondary outcome was RA remission one year after diagnosis (DAS28 score <2.6)6. Presence of diabetes was defined by physician diagnosis. Statistical analyses comprised mixed linear models and logistic regression. Potential confounders included smoking, BMI, alcohol intake, age, HAQ score and rheumatoid factor at baseline. Gender was treated as effect modifier.
Results 35 (4.2%) out of the 840 included patients had DM2 at baseline. Mean DAS28 values at baseline were 5.33 (SE 0.20) for diabetic and 5.04 (SE 0.05) for non-diabetic patients (p<0.21). At baseline only age was relevantly different between non-diabetic and diabetic patients in univariable analyses (53.8 (SE 0.50) versus 56.0 (SE 2.44) years, p=0.04), and was therefore included as confounder in the analyses. The difference in DAS28 scores during the first year after RA diagnosis between diabetic and non-diabetic patients is presented in Table 1.The parameter estimate of the interaction between gender and DM2 was -0.08 (SE 0.41), indicating no statistically significant interaction (p=0.85). Moreover, after one year, four (11.8%) diabetic and 186 (23.1%) non-diabetic patients were in remission. Table 1 presents the effect of DM2 on achieving remission one year after RA diagnosis, which was not statistically significantly different for males and females (parameter estimate 1.36, SE 1.24, p=0.28).
Conclusions There was no large influence of having DM on baseline DAS28, response in DAS28 scores and remission percentages during the first year after RA diagnosis; this was the same for male and female patients.
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Disclosure of Interest None declared