Circadian pattern and the effect of standardized physical exercise on procollagen IIA N-peptide (PIIANP) in rheumatoid arthritis at different stages and in healthy individuals.
BACKGROUND
Variant collagen IIA is re-expressed in diseased cartilage. Low procollagen IIA N-peptide (PIIANP) levels in serum have recently been reported in rheumatoid arthritis (RA). We investigated circadian rhythmicity and effect of physical activity on PIIANP in early and longstanding RA and in healthy subjects.


METHODS
Patients with early and longstanding RA and controls were included. Fasting and serial blood samples were collected during 24 h. PIIANP response to physical activity was studied before and serially after standardized exercise.


CONCLUSIONS
In RA at different stages and healthy individuals, PIIANP exhibited no circadian rhythmicity, and PIIANP in serum was not influenced by physical activity.
Christensen
Anne Friesgaard
AF
Department of Rheumatology, Odense University Hospital, Odense, Denmark. a.friesgaard@gmail.com
Lottenburger
T
T
Lindegaard
H M
HM
Junker
K
K
Hørslev-Petersen
K
K
Junker
P
P
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid; D016022:Case-Control Studies; D002940:Circadian Rhythm; D024043:Collagen Type II / Q000097:blood*; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
D024043:Collagen Type II