Anemia and disease activity indexes in women with rheumatoid arthritis

AIMS: To evaluate disease activity indexes in female patients with rheumatoid arthritis, Anemic and Non-anemic, correlating them with hemoglobin levels. METHODS: A cross-sectional study involved women with rheumatoid arthritis classified into two groups: 1) Anemic (hemoglobin <12 g/dL)and 2) Non-anemic. Disease activity was measured by Disease Activity Index (DAS28), using different inflammatory markers: Erythrocyte Sedimentation Rate (ESR) and C-reative Protein (CRP). This score also uses the number of swollen and painful joints and an overall assessment of the disease on Visual Analogue Scale (VAS). An assessment of functional capacity by the Health Assessment Questionnaire (HAQ) was also performed. The statistic used Student's t-Test, Mann-Whitney, Wilcoxon, Fisher, likelihood ratio and Spearman correlation tests. It was considered significant p < 0,05. RESULTS: Twenty-four patients were included, eight patients in the Anemic group and 16 patients in the Non-anemic group. The groups were similar in terms of clinical, demographic and treatment characteristics, differing only in relation to rheumatoid factor, positive in all anemic participants and in 56,2% of non anemic participants. DAS28 ESR (median 6,05; interquartile range [IQR] 5,21-7,76), DAS28 CRP (median 4,32; IQR 3,98-5,92) and VAS (median 66,50 mm; IQR 54,75-80,50) were significantly higher in Anemic group. DAS28 ESR (-0,418) and VAS (-0,426) showed a significant negative correlation with hemoglobin level. DAS28 ESR and DAS28 CRP values were different in the same group, showing a discrepancy in the categorization of disease activity. In Anemic group, DAS28 ESR value (median 6,05; IQR 5,21-7,76) was higher in relation to DAS28 CRP (median 4,32; IQR 3,98-5,92). A less discrepant increase of DAS28 ESR (median 4,01; IQR 3,05-5,68) compared to DAS28 CRP (median 3,06; IQR 2,18-4,66) was observed in Non-anemic group. CONCLUSIONS: Anemia was associated with worse disease activity indexes in women with rheumatoid arthritis, being correlated with greater pain intensity and increase of DAS28 ESR score.