Data from two large clinical trials of rheumatoid arthritis (GO-BEFORE and GO-FORWARD) have led researchers to a surprising revelation: Patients who are overweight or obese are at reduced risk of radiographic progression, as measured by either X-ray or MRI.
In this brief podcast the lead author of the analysis, Joshua Baker MD, describes the results and ponders what they mean to rheumatology practice.
Dr. Baker is assistant professor of rheumatology and epidemiology at the Hospital of the University of Pennsylvania and the Philadelphia VA Medical Center.
• This was a retrospective analysis of data from clinical trials of golimumab use in rheumatoid arthritis. What led you to study the particular aspect of obesity?
• Can you briefly describe the findings for us?
• What's already known from previous studies about the effect of BMI on the effectiveness of drugs that are used for RA?
• What insights do you have into the possible mechanisms behind what's going on in this relationship?
• What do you think are the specific clinical implications of what you've found for practicing rheumatologists?
• Are you and your group planning a followup study, and if so, what?
• Not all RA is the same. So different ways of trying to understand how people got to where they are, what their disease severity is, what their different risks are, are very important, and may also help us to understand how aggressive we should be with treatment, what treatments to use, and just how worried we should be about somebody in terms of their risk over time.
• I think this sort of speaks to the idea that there's something different about the subjects that are obese. They may have a different disease phenotype.
• People with severe RA over time may tend to lose weight ... What this study suggests is that, even after they've already lost the weight, their phenotype of disease would still put them at risk for radiographic progression.
• The other possibility is that low body mass actually puts patients at risk because of some biologic mechanism. ... Similarly, people who are overweight have more lean mass ... and it may be that people who have a higher BMI are protected against various kinds of bone loss.
• I certainly would not recommend that anybody tell their patients to gain weight. ... What this does tell us that when you're seeing a patient for the first time in clinic and you notice that they are underweight or have a low BMI, it may ... make you more concerned about them in terms of their long-term risk.
Baker JF, Østergaard M, George M, et al. Greater body mass independently predicts less radiographic progression in X-ray and MRI over 1-2 years. Ann Rheum Disdoi:10.1136/annrheumdis-2014-205544. Published online Aug. 4, 2014.