Laboratory measures of systemic inflammation, particularly C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR), are routinely used in the diagnosis and assessment of disease activity in patients with rheumatoid arthritis (RA). Prior research has associated higher levels of CRP with greater body mass index (BMI) and adiposity in the general population, especially among women. This association may indicate that these inflammatory markers may perform as a biomarker of disease activity among obese patients with RA.
To assess this possibility, Michael D. George, MD, MSCE, from the University of Pennsylvania, Philadelphia, and colleagues designed a study to evaluate the connection between BMI and inflammatory markers in people with RA, determine if these associations are similar to patients without RA and examine the potential effect of obesity on disease activity. Their findings were published in December 2017 Arthritis Care & Research.
Using data that from two RA cohorts, the cross-sectional Body Composition (BC) cohort and the longitudinal Veterans Affairs Rheumatoid Arthritis (VARA) registry, researchers identified 2,103 patients with RA. For comparison, researchers used data from the National Health and Nutrition Examination Survey to evaluate the general population.