The aim of this study was to analyze the relationship between serum pro-hepcidin concentration and the anemia profiles of rheumatoid arthritis (RA) and to estimate the pro-hepcidin could reflect the disease activity of RA. RA disease activities were measured using Disease Activity Score 28 (DAS28), tender/swollen joint counts, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Anemia profiles such as hemoglobin, iron, total iron binding capacity (TIBC), ferritin, and transferrin levels were measured. Serum concentration of pro-hepcidin, the prohormone of hepcidin, was measured using enzyme-linked immunosorbent assay (ELISA). Mean concentration of serum pro-hepcidin was 237.6+/-67.9 ng/mL in 40 RA patients. The pro-hepcidin concentration was correlated with rheumatoid factor, CRP, ESR, and DAS28. There was a significant correlation between pro-hepcidin with tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6. The pro-hepcidin concentration was significantly higher in the patients with active RA (DAS28>5.1) than those with inactive to moderate RA (DAS28< or =5.1). However, the pro-hepcidin concentration did not correlate with the anemia profiles except hemoglobin level. There was no difference of pro-hepcidin concentration between the patients with anemia of chronic disease and those without. In conclusion, serum concentration of pro-hepcidin reflects the disease activity, regardless of the anemia states in RA patients, thus it may be another potential marker for disease activity of RA.
Adult ; Aged ; Anemia/*blood ; Anti-Bacterial Agents/blood ; Antimicrobial Cationic Peptides/*blood ; Arthritis, Rheumatoid/*blood/immunology/*physiopathology ; Biological Markers/blood ; Female ; Humans ; Interleukin-1beta/blood/immunology ; Interleukin-6/blood/immunology ; Male ; Middle Aged ; Protein Precursors/*blood ; *Severity of Illness Index ; Tumor Necrosis Factor-alpha/blood/immunology

BACKGROUND/AIMS: 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.
Adult ; Age Factors ; Aged ; Arthritis, Rheumatoid/blood/diagnosis/*metabolism/physiopathology ; Biological Markers/blood ; Body Mass Index ; Case-Control Studies ; Cross-Sectional Studies ; *Energy Metabolism ; Female ; Humans ; Inflammation Mediators/blood ; Middle Aged ; Peptides, Cyclic/immunology ; Predictive Value of Tests ; *Rest ; Rheumatoid Factor/blood ; Severity of Illness Index