Obesity may obstruct rheumatoid arthritis management, study highlights

RA affects between 0.5 and 1% of adults in the developed world with between 5 and 50 per 100,000 people newly developing the condition each year. ©iStock/stockdevil

Excess weight and obesity can interfere in the diagnosis and care of autoimmune conditions such as rheumatoid arthritis as the impact of diet on the inflammation process is highlighted. 

High body mass index (BMI) was associated with greater levels of the rheumatoid arthritis (RA) biomarkers C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) in women with and without RA.

“The increase in these levels of inflammation was not because rheumatoid arthritis was worse in these women,” said Dr Michael George of the University of Pennsylvania Health System.

In fact, we found that obesity leads to very similar increases in these lab tests even in women without rheumatoid arthritis.”

Meanwhile, low BMI was associated with a greater levels of CRP and ESR in men with RA.

Dr George believed that RA and obesity could both contribute to levels of inflammation, making the diagnosis of lab tests more complicated.

The findings also raise questions about the relationship between weight and inflammation and how it may differ between men and women.

“Physicians might assume that high levels of inflammation mean that a patient has rheumatoid arthritis or that their rheumatoid arthritis requires more treatment when in fact a mild increase in levels of inflammation could be due to obesity instead,” he explained.

Study criteria

In the study, BMI associations with CRP and ESR were investigated in two RA sample groups.

One measured the cross-sectional Body Composition (BC) and included whole body measures of fat mass index of 451 men and women aged between 18-70 years.

The other group, known as the VA Rheumatoid Arthritis (VARA) Registry Cohort, consisted of 1,652 males and females over the age of 18.

Follow-up visits included the questionnaires that asked about swollen and tender joint counts, inflammatory markers, pain scores, and patient and physician disease assessment scores.

The team found among women with RA and in the general population, greater BMI was associated with greater CRP, especially among women with severe obesity.

Positive associations between BMI and ESR in women were more modest. In men with RA lower BMI was associated with greater CRP and ESR, contrasting positive associations among men in the general population.

“In this study, obesity was associated with greater CRP in women with RA, independent of other components of disease activity,” the study stated.

“A similar association was observed in a non-RA sample, suggesting that elevated CRP values among obese women with RA are not reflective of greater RA disease activity but rather are an expected phenomenon related to adiposity.”

Inflammation and weight

Inflammation has already been shown to have different effects on body composition in men and women.

This could explain why different associations were seen among men and women with RA.

While a lower BMI was associated with a greater swollen joint count among men with RA, differences in joint counts and patient global scores alone could not explain the higher CRP and ESR in men with lower BMI.

“Furthermore, because obesity may be expected to impact the reliability of other component measures of disease activity, clinicians may tend to rely more on objective measures such as CRP for diagnosis or to make treatment decisions,” the study concluded.

Source: Arthritis Care & Research

Published online ahead of print: DOI 10.1002/acr.23229

“The impact of obesity and adiposity on inflammatory markers in patients with rheumatoid arthritis.”

Authors: Michael George et al.

Related News

'The finding of sodium being a risk factor for the development of RA among smokers is intriguing, as it may explain discrepancies in previous studies of diet as a risk factor for RA,' said researcher.

Smokers consuming too much sodium may have greater rheumatoid arthritis risk: Study

©iStock/marrakeshh

Mind, body and spirit: The holistic tea trend

'People are angry about the daily difficulties they experience with packaging'. © iStock/Highwaystarz-Photography

Is packaging for the elderly the next untapped market?

The research suggests that a good diet may not be able to deal effectively with the consequences of stress on the human body. ©iStock

Healthier fat benefits ‘cancelled out' by stressful events, study suggests

Submit a comment

Your comment has been saved

Post a comment

Please note that any information that you supply is protected by our Privacy and Cookie Policy. Access to all documents and request for further information are available to all users at no costs, In order to provide you with this free service, William Reed Business Media SAS does share your information with companies that have content on this site. When you access a document or request further information from this site, your information maybe shared with the owners of that document or information.