title: Resting energy expenditure is not associated with disease activity in women with rheumatoid arthritis: cross-sectional study.
abstract: OBJECTIVE
  Increased resting energy expenditure (REE) in rheumatoid arthritis (RA) patients is thought to be caused by hypermetabolism associated with production of proinflammatory cytokines. Our aim in the present study was to explore the possible association between REE and disease activity in females with RA.
  
  
  METHODS
  A total of 499 female RA patients were recruited to this cross-sectional study assessing REE scores on disease activity indices (the routine assessment of patient index data 3 [RAPID3], the disease activity score 28, and the clinical/simplified disease activity index [CDAI/SDAI]) and the levels of RA-associated autoantibodies (rheumatoid factor and anticyclic citrullinated peptide [anti-CCP] antibodies). Age-matched healthy female controls (n = 131) were also enrolled.
  
  
  RESULTS
  REE did not differ between RA patients (all patients, and those in remission or not) and controls, or between RA patients in remission or not (p > 0.05 for all comparisons). Increased REE in total RA patients was associated with younger age and a higher body mass index (BMI) (p < 0.001 and p < 0.001, respectively), but not with disease activity index scores on any of RAPID3, CDAI, or SDAI. BMI was the only clinical parameter exhibiting a significant relationship with REE quartiles (Q1 to Q4; p < 0.001); none of disease duration, functional status, or anti-CCP antibody titer in RA patients was significantly related to REE, based on analysis of covariance.
  
  
  CONCLUSIONS
  We found no association between REE and disease activity in RA patients, implying that energy metabolism in RA patients might be independent of RA-associated systemic inflammation.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Arthritis and Autoimmunity Research Center, Catholic University of Daegu School of Medicine, Daegu, Korea.
authors.forename: Jung-Yoon
authors.initials: JY
authors.lastname: Choe
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Arthritis and Autoimmunity Research Center, Catholic University of Daegu School of Medicine, Daegu, Korea.
authors.forename: Sung-Hoon
authors.initials: SH
authors.lastname: Park
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Arthritis and Autoimmunity Research Center, Catholic University of Daegu School of Medicine, Daegu, Korea.
authors.forename: Hwajeong
authors.initials: H
authors.lastname: Lee
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Catholic University of Daegu School of Medicine, Daegu, Korea.
authors.forename: Hyun Hee
authors.initials: HH
authors.lastname: Kwon
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Arthritis and Autoimmunity Research Center, Catholic University of Daegu School of Medicine, Daegu, Korea.
authors.forename: Seong-Kyu
authors.initials: SK
authors.lastname: Kim
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology; D011237:Predictive Value of Tests; D012146:Rest; D012217:Rheumatoid Factor / Q000097:blood; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor
keywords: Arthritis, rheumatoid; Disease activity index; Resting energy expenditure