Circadian rhythm of C-reactive protein in patients with rheumatoid arthritis
Herold, M.; Günther, R.
Progress in Clinical and Biological Research 227b: 271-279
1987
ISSN/ISBN: 0361-7742 PMID: 3628337 Document Number: 304257
Ten men with classic rheumatoid arthritis were studied for 23 days in Badgastein, Austria, in August, 1980. One man (patient 07) showed a marked increase of disease activity after a few days. C-reactive protein (CRP) concentrations increased from 8.7 mg/dl on day 2 to 13.0 mg/dl on day 16. CRP values expressed as percent mean of a day showed a significant circadian rhythm with the acrophase at -30 degrees. For the same patient we also found significant circadian rhythms in grip strength and pearl stringing with acrophases in the evening and a circadian rhythm in walking time with the acrophase in the early morning. Seven of the ten men in the study had elevated CRP concentrations during the 3 weeks of observation. Population-mean cosinor results of CRP, grip strength, pearl stringing, and walking time revealed acrophases similar to the single cosinor results of patient 07. Our results suggest that inflammation in rheumatoid arthritis is a circadian rhythmic process with lowest disease activity in the evening.