Back to Journals » Journal of Inflammation Research » Volume 4

The effect of disease activity on body composition and resting energy expenditure in patients with rheumatoid arthritis

Authors Binymin K, Herrick AL, Carlson GL, Hopkins S

Published 23 May 2011 Volume 2011:4 Pages 61—66


Review by Single anonymous peer review

Peer reviewer comments 2

K Binymin1,3, AL Herrick1, GL Carlson2, SJ Hopkins2
1University of Manchester, Rheumatic Diseases Centre, 2Infection Injury and Inflammation Group, and Brain Injury Research Group, Manchester Academic Health Science Centre and University of Manchester Faculty of Medical and Human Sciences, Salford Royal Hospitals NHS Trust, Salford, UK; 3Southport District General Hospital, Southport, UK

Introduction: Cachexia is associated with rheumatoid arthritis (RA), but whether it is attributable primarily to reduced dietary intake or increased metabolism is unclear, as is the association with inflammation. To examine whether rheumatoid cachexia is related to increased energy expenditure, reduced food intake, or an inflammatory cytokine response we undertook a prospective, longitudinal study of patients with RA, during periods of relative relapse and remission of inflammation.
Methods: Sixteen patients admitted to hospital with a flare of RA were assessed clinically to determine disease activity and were re-examined 6 weeks later. Their fat-free mass (FFM), dietary intake, resting energy expenditure (REE), and plasma concentrations of interleukin-6 (IL-6) were also measured. Data were compared with those from 16 healthy, age- and sex-matched controls.
Results: At baseline the body weight, body mass index, and FFM of patients with RA were significantly lower than those of controls. Disease activity scores of patients (6.39 ± 0.8) were reduced when the patients were re-examined 6 weeks later (5.23 ± 1.26) and FFM was no longer statistically different from that of controls (visit 1 = 25.8 ± 10.1 and visit 2 = 26.8 ± 9.5 versus controls = 32.3 ± 10.9). There were no differences in food intake between patients and controls or between patients studied at the 2 time points, but REE was greater in patients after correcting for FMM (visit 1 = 62.2 ± 24.7, visit 2 = 59.7 ± 26.3 versus controls = 46.0 ± 13.7). Plasma IL-6 concentrations were significantly higher in patients than controls. Although IL-6 was not significantly correlated with REE, lower REE measurements were not observed when the plasma IL-6 concentration increased.
Conclusion: Reduced FFM in patients with RA is not attributable to reduced food intake. Energy expenditure is greater in patients when corrected for FFM, particularly in patients with acute flares of disease activity. Although clearly not the only factor involved, increased production of IL-6 may contribute to increasing REE.

Keywords: rheumatoid arthritis, cachexia, free-fat mass, fat mass, resting energy expenditure, interleukin-6

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]