Age at onset and comorbidity burden, especially obesity, have increased at rheumatoid arthritis (RA) presentation over 25 years, reflecting wider demographic trends at the population level, a recent study found. A total of 2,701 patients were recruited over 25 years to 2 RA inception cohorts. Trends in demographic and baseline clinical/laboratory and radiographic variables and comorbidities were estimated using mixed-effects models. Researchers found:

• Age at onset increased from 53.2 to 57.7 years in 1990 and 2010, respectively.
• After controlling for treatment at the time of assessment, erythrocyte sedimentation rate decreased and hemoglobin increased over time.
• The overall prevalence of comorbidity increased from 29.0% in 1990 to 50.7% in 2010, mainly due to cardiovascular and non-cardiac vascular conditions, including hypertension.
• There was a significant increase in body mass index, resulting in an increase in the prevalence of obesity from 13.3% in 1990 to 33.6% in 2010.