Urinary albumin excretion in patients with rheumatoid arthritis in a large cross-sectional study

Abstract

While there is a lot of evidence published on the association of cardiovascular (CV) disease and rheumatoid arthritis (RA), little is known about urinary albumin excretion (UAE)-a marker of CV risk-in this particular high-risk population. Therefore, we investigated UAE in a large cross-sectional study. We used data from the US National Health and Nutrition Examination Survey (NHANES), including the years 2007-2012. Primary outcome was the proportion of patients with a urinary albumin-creatinine ratio (ACR) >30mg/g. A total of 14,648 study participants (representing a population size of 174,663,008) with available ACR were included in the study (14,179 without RA and 469 with RA). In the RA group, the proportion of patients with an ACR >30mg/g was 10.46% (95% CI 7.47-14.45%) and in the non-RA group this proportion was 13.39% (95% CI 12.65-14.16%; p = 0.09). There was a strong association between RA and DM (OR 5.84; 95% CI 4.48-7.62). In the RA group, significantly more patients had a former CV event (OR 3.01; 95% CI 2.28-3.97). Adjustments for DM, smoking status, former CV event, age, systolic blood pressure, and gender did not substantially alter the association between RA and ACR >30mg/g (OR 0.82; 95% CI 0.51-1.33). We did not find evidence for a difference in UAE in patients with or without RA, despite the fact that RA was associated with DM and, in addition, RA patients more often had a previous CV event. These findings may support the assumption that despite an increased CV risk, UAE does not play a major role in RA patients.