Obesity's Negative Impact on Rheumatoid Arthritis
The negative impact of obesity on various aspects of rheumatoid arthritis has been well established. A 2013 study highlighted findings that suggested that overweight patients with rheumatoid arthritis (RA) have more disease activity, lower rates of remission and are twice as likely to require tumor necrosis factor (TNF) inhibitor drugs compared to healthy weight patients with the disease.
A 2016 study published in Current Rheumatology Reports found that obesity can be a driver of RA, modestly increasing risk, and is associated with more subjective measures of disease activity and poor treatment response. In this study, obesity did seem to confer a small protective impact on joint damage and mortality rates (this finding was later questioned).
New research presented at the 2017 ACR/ARHP Annual Meeting suggests that a higher BMI in RA patients is linked to lower rates of remission and higher rates of disability.
Rheumatoid arthritis affects an estimated 1.3 million Americans, and women are twice as likely as men to develop RA. Obesity is linked to general inflammation and RA is a disease where inflammation instigates joint disease. Though joints are the major body parts affected by RA, it can certainly affect other organs.
Obesity is increasing in prevalence in the U.S. and worldwide, so this new research looked at how obesity-driven inflammation resulted in clinical disease activity and functional disability. Researchers focused on BMI measurement and how it seemed to relate to either disease remission, lower disease activity or better or worse joint function in RA.
The process of inflammation and what it does in the body is a source of scrutiny by the health and research communities because of its role in disease evolution and disease severity. There seems to be growing evidence that obesity may itself be a low grade chronic inflammatory condition — so it may have a lot in common with RA, even as it raises the risk of developing RA. In the case of RA, there is an autoimmune-driven inflammatory component. Coupled with obesity, this may heighten the negative outcomes that the researchers noted.
The researchers extrapolated data from the Early RA Study (ERAS) and the Early RA Network (ERAN). These studies had robust subject numbers and 25-year follow-up in the ERAS study and 10-year follow-up of the ERAN subjects.
At baseline, BMI was 25.5 in the ERAS group of subjects, and 27.6 in the ERAN group. Over the first five years of follow-up, BMIs continued to skew higher, meaning overweight subjects moved closer to a diagnosis of obesity and patients diagnosed as obese at baseline continued to gain weight.
When adjusted for age, gender and age at time of recruitment, a higher BMI was found to be associated with reduced remission of disease based on two scores (R-DAS and L-DAS). These are two measurements of low disease activity. The findings validated the working theory that obesity increased a patient’s odds of higher disease-driven disability (by 63 percent) and higher DAS scores also strongly predicted higher disability.
It’s important to note that though these scoring tools are considered both useful and helpful, many clinicians prefer asking patients a litany of questions, running specific blood tests, using radiographic assessments and using tools that evaluate range-of-motion during daily tasks (RAPID-3) to diagnose and grade RA.
The researchers offered some important takeaway messages from this new research:
Obesity must be assessed in the RA patient.
Obesity can drive RA risk.
Obesity likely worsens the RA condition through an inflammatory mechanism.
Obesity in the presence of RA has several negative consequences.
With a goal in mind of reducing RA flare ups, improving remission rates, and lowering the level of disability associated with the disease, screening for and treating obesity should be a strong consideration. If obesity is a co-morbid condition with RA, then it needs to be part of the treatment management plan. Obesity is considered to be a hard-to-treat disease, but in an individual with RA, there may be some motivation to reverse obesity or at minimum to lose weight to improve remission rates.
In terms of the nutrition component of obesity management in the presence of RA, recommending and implementing a consult and regular follow up with a dietician or nutritionist should be part of the management protocol if insurance or personal finances can cover the costs.
The Mediterranean Diet is considered an anti-inflammatory diet because of its emphasis on non-meat protein options and healthy fats (fish, nuts, olive oil). RA patients may also be more sensitive to meat, sweets and refined sugar, so removing these “inflammatory foods” from the diet may lower general body inflammation and help with weight loss.
A weight loss program should be personalized to individuals, taking into account all current diagnoses, goal weight, food preferences and finances.
The goal of the exercise part of this prescription should be to aim for some aerobic, calorie-burning activity daily and strength training several times a week. Remember that you may have varying levels of movement limitation which will hopefully improve with weight loss and with physical activity, over time.
Physicians do need to be aware of possible bias when it comes to patients who have a diagnosis of obesity and RA. A just-released study in the Annals of the Rheumatic Diseases found that when MRIs were used to assess disease activity in these patients, rates of low disease activity were similar in RA patients with and without a diagnosis of obesity. The researchers in this study suggest that obesity creates bias in calculating disease activity scores, which can lead to an incorrect perception of “cause and effect.” The researchers wanted to make sure that doctors who evaluate and treat this patient population not let obesity color their judgement of true disease activity.
Still, limiting obesity in patients who have more than one disease diagnosis will more than likely help to improve overall health and may also reduce certain symptoms or severity of other diagnoses.
