Body Mass Index Linked to Rheumatoid Arthritis Remission

Patients significantly overweight or underweight less likely to remain in remission.

The ability of rheumatoid arthritis (RA) patients to achieve a sustained remission of the disease is impacted by their body mass index (BMI), a recent study found.

In a study presented at the American College of Rheumatology meeting on November 16, 2014, researchers found that in patients who received an RA diagnosis within the past year, those who were significantly underweight or overweight were least likely to remain in remission.

"What's striking is that if you look at the BMI classifications, all the patients in the underweight or overweight categories were much less likely to achieve sustained remission compared to those with a normal BMI," said rheumatologist Susan Goodman, MD, in a press release. "Patients who were severely obese had an even lower chance of achieving sustained remission. Individuals in the highest BMI categories also had more inflammation and more pain."

Patients were grouped by BMI categories and had their symptoms measured prospectively over 3 years through the Canadian Early Arthritis Cohort study using the Disease Activity Score for RA (DAS28).

Sustained RA remission was defined in the study as having low disease activity during 2 consecutive doctor visits for a duration of 3 to 6 months apart.

A total of 944 patients were split into 6 groups based on World Health Organization BMI classifications.

Just 2% of patients were underweight, while 65% were classified as either overweight or obese. Patients who registered a higher BMI tended to be older, female, and had worse function. Patients with a very low or high BMI also exhibited more inflammation, while those with a low or normal BMI were more often smokers.

It was also found that early use of methotrexate, nonsmoker status, and response to treatment within the first 6 months increased the chances of sustained remission independently of a patient’s BMI.

The researchers next plan to initiate an American Early Arthritis Cohort study that will enroll patients with early inflammatory arthritis thought to be RA for information on outcomes and best practices.

"Our findings represent the first study to present evidence that BMI should be considered among the modifiable risk factors for poor RA outcomes," Dr. Goodman said. "There are many things patients can do to manage the disease. Along with timely diagnosis and treatment, weight control and other good practices can result in better outcomes."