MADRID – Being overweight or obese makes it much more difficult for patients with early rheumatoid arthritis to achieve remission and significantly increases the chance that they will need a biologic by the end of the first treatment year.
The finding speaks to the role that weight can play in RA management, Dr. Elisa Gremese said during the annual European Congress of Rheumatology.
"Obesity is considered a systemic low-grade inflammatory state, and adipose tissue is a proinflammatory cytokine-producing factory," Dr. Gremese said during a press briefing. "Studies continue to show that obesity may be contributing to the rise in RA and is associated with a worse course of disease and more disability."
She examined the relationship between weight and first-year therapeutic outcomes among 346 patients with early rheumatoid arthritis; 33% of these had very early disease of less than 6 months’ duration. Normal weight was considered to be a body mass index of less than 25 kg/m2; overweight was a BMI of 25-30 kg/m2, and obesity was a BMI of greater than 30 kg/m2. About half of the patients (47%) were normal weight, 39% were overweight, and the remainder were obese, said Dr. Gremese of the Università Cattolica del Sacro Cuore in Rome.
All patients received up to 25 mg methotrexate each week, with or without steroids. In cases in which a patient didn’t achieve at least a "good" response (a change of at least 1.2 on the Disease Activity Score [DAS] 28), a tumor necrosis factor (TNF) blocker was added to the treatment regimen.
Overweight and obese patients had a significantly lower rate of remission as measured by both the DAS and the Clinical Disease Activity Index (CDAI) Score.
At 12 months, 49% of the normal weight group, 29% of the overweight group, and 34% of the obese group reached remission as measured by the DAS. Remission according to the CDAI criteria occurred in 50% of the normal weight group, 37% of the overweight group, and 31% of the obese group.
By the end of the first year, significantly more overweight and obese patients were taking an anti-TNF medication than were normal weight patients (29% and 28%, compared with 16%, respectively).
A multivariate analysis found that having a body mass index of at least 25 kg/m2 at baseline more than doubled the risk of DAS nonremission (odds ratio, 2.4) at 12 months, and nearly doubled the risk of CDAI nonremission (OR, 1.8).
"In the general population, the prevalence of overweight and obesity now reaches 50%," Dr. Gremese said. "We should look at this as a modifiable risk factor" that can be changed to help patients reach a better outcome.
She added that her group has started a dedicated outpatient center with a multidisciplinary program to help patients with RA and other rheumatic diseases with weight loss. "They work with a dietitian and psychologist as well as rheumatologist," she said.
Dr. Gremese had no financial declarations.