Does Anemia Independently Influence the Erythrocyte Sedimentation Rate in Rheumatoid Arthritis? A Multivariate...

Area of Science:

• Rheumatology
• Hematology
• Clinical Chemistry

Background:

• Anemia is common in North India, complicating erythrocyte sedimentation rate (ESR) interpretation in rheumatoid arthritis (RA).
• Evaluating the independent associations of inflammation, autoantibody status, and anemia with ESR elevation is crucial in RA patients.

Purpose of the Study:

• To determine the independent predictors of elevated ESR in RA patients.
• To investigate the association between anemia and ESR, and to analyze morphologic patterns of anemia in this cohort.

Main Methods:

• Retrospective cross-sectional analysis of 152 RA patients.
• Multivariate logistic regression to identify independent predictors of elevated ESR and anemia.
• Classification of anemia based on mean corpuscular volume (MCV) and comparison of inflammatory markers.

Main Results:

• C-reactive protein (CRP) positivity was the strongest independent predictor of elevated ESR (aOR 7.81, p<0.001).
• Anemia was not independently associated with elevated ESR (aOR 1.45, p=0.305) after adjustment.
• Among anemic patients, normocytic anemia (54%) showed significantly higher ESR and CRP values compared to microcytic anemia.

Conclusions:

• ESR elevation in RA is independently associated with inflammatory activity (CRP), not anemia.
• ESR remains a clinically relevant marker for assessing inflammatory burden in RA when used with other laboratory parameters.
• Normocytic anemia in RA patients is associated with higher inflammatory markers, suggesting a distinct clinical profile.