PARIS – The higher disease activity scores seen in obese patients with rheumatoid arthritis may be driven by the proinflammatory state that is associated with obesity, Dr. Christopher Sparks reported in a press conference at the annual European Congress of Rheumatology.
Although obese RA patients tend to have less radiographic joint damage than do normal-weight RA patients, they have comparable DAS (disease activity score) 28. With the clinical focus on treat-to-target, an approach guided by DAS scores, obese RA patients may be getting more aggressive treatment. The finding may explain why obese patients with RA have better outcomes than normal-weight and thin RA patients, said Dr. Sparks, a clinical research fellow at the University of Liverpool, England.
Mary Jo Dales/Frontline Medical Media
Dr. Christopher Sparks
Dr. Sparks and his colleagues used an international RA database to examine two patient subgroups: those diagnosed with RA in the previous year and those with longstanding RA. The 3,534 patients were stratified by their body mass index into five groups: underweight (less than 18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), obese (30-34.9 kg/m2), and obese II (35 kg/m2 or more). In the 1,981 patients with longstanding disease, median disease duration was about 7 years; the other 1,553 patients had disease duration of 1 year or less.
About 73% of the each cohort was female, and the distribution of BMI measures was similar for the two cohorts.
The groups were compared by BMI and RA disease measures that included DAS28, erythrocyte sedimentation rate, tender joint count; swollen joint count; and visual analog scale disease activity.
After adjusting for RA risk factors, obesity (BMI of 28 kg/m2 or greater) was significantly associated with a DAS28 exceeding 5.1, an elevated erythrocyte sedimentation rate, high tender joint count, and high visual analog scale score. For instance, compared with normal weight and overweight patients, underweight and both groups of obese patients were 1.5-2.2 times as likely to have a DAS28 exceeding 5.1, Dr. Sparks reported.
He had no financial disclosures.