title: Within-day variation and influence of physical exercise on circulating Galectin-3 in patients with rheumatoid arthritis and healthy individuals.
abstract: Galectin-3 has been suggested as a pro-inflammatory mediator in rheumatoid arthritis (RA). Previous studies have reported overexpression of Galectin-3 in RA synovitis and increased levels in synovial fluid and serum in long-standing RA compared with osteoarthritis and healthy controls. Our objectives were to study whether serum Galectin-3 (1) exhibits circadian variation and/or (2) responds to exercise in RA and controls. The study on circadian patterns (1) comprised eleven patients with newly diagnosed RA, disease duration less than 6 months (ERA), 10 patients with long-standing RA [5-15 years (LRA)] and 16 self-reportedly healthy control subjects. During 24 h, 7 blood samples were drawn at 3-h intervals starting at 10 a.m. through 10 p.m. and at 7 and 10 a.m. on the following day. The study on the effect of physical activity (2) included 10 patients with ERA, 10 with LRA and 14 controls. The participants underwent a standardized exercise programme and four blood samples were drawn before, during and after exercise. Serum Galectin-3 was quantified by ELISA (R&D systems). (1) Galectin-3 was increased at baseline in both RA subsets (P = 0.08). There were no diurnal oscillations (P = 0.85). Day-to-day variation amounted to 3%. (2) Baseline Galectin-3 was increased in LRA versus controls and ERA (P < 0.01 and 0.05). Physical exercise induced 10-15% Galectin-3 increments in RA and controls (P < 0.001) peaking after 1-3 h. To conclude, Galectin-3 did not exhibit circadian variation. Day-to-day variation was 3%. Exercise elicited comparable increments in patients with RA of short and long duration and controls, approaching normal after 1-3 h.
authors: Department of Rheumatology, Odense University Hospital, Odense C, Denmark.
authors: S F
authors: SF
authors: Issa
authors: Department of Rheumatology, Vejle Hospital, Vejle, Denmark.
authors: A F
authors: AF
authors: Christensen
authors: Department of Rheumatology, Vejle Hospital, Vejle, Denmark.
authors: T
authors: T
authors: Lottenburger
authors: Institute of Molecular Medicine, Dept. Cancer & Inflammation, University of Southern Denmark, Odense C, Denmark.
authors: K
authors: K
authors: Junker
authors: Department of Rheumatology, Odense University Hospital, Odense C, Denmark.
authors: H
authors: H
authors: Lindegaard
authors: King Christian X Hospital for Rheumatic Diseases, Graasten, Denmark.
authors: K
authors: K
authors: Hørslev-Petersen
authors: Department of Rheumatology, Odense University Hospital, Odense C, Denmark.
authors: P
authors: P
authors: Junker
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood*; D001798:Blood Proteins; D002940:Circadian Rhythm; D015444:Exercise; D005260:Female; D037502:Galectin 3 / Q000097:blood*; D037161:Galectins; D006801:Humans; D007249:Inflammation / Q000276:immunology; D018836:Inflammation Mediators / Q000097:blood*; D008297:Male; D008875:Middle Aged
chemical_list: D001798:Blood Proteins; D037502:Galectin 3; D037161:Galectins; D018836:Inflammation Mediators; C428445:LGALS3 protein, human