The effect of single and repeatedly high concentrations of C-reactive protein on cardiovascular and non-cardiovascular mortality in patients starting with dialysis.
BACKGROUND
Single measurements of C-reactive protein (CRP) predict cardiovascular mortality in dialysis patients. However, CRP can be temporarily elevated due to infections. Therefore, we investigated the effect of single and repeatedly high concentrations of CRP on cardiovascular and non-cardiovascular mortality in incident dialysis patients.


METHODS
In the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD), patients starting with dialysis were enrolled between 1997 and 2002. From 635 patients, plasma CRP concentrations were determined at 3 and 6 months of follow-up. Concentrations >10 mg/l were regarded as 'high'. Patients were followed until time of death, or censored at the end of follow-up (1 May 2004). Cox regression models were performed to compare mortality between patients with repeatedly low CRP, with varying CRP and with repeatedly high CRP.


RESULTS
At the end of follow-up, 247 patients had died, of which 107 patients died of cardiovascular disease (47.8%). Patients with low CRP(3 months) and high CRP(6 months) were at increased cardiovascular [adjusted hazard ratio (HR): 2.59, 95% CI: 1.25-5.37] and non-cardiovascular (adjusted HR: 2.18, 95% CI: 1.11-4.28) mortality risk compared with patients with low CRP on both occasions. Moreover, patients with high CRP on both occasions had a higher cardiovascular (adjusted HR: 1.51, 95% CI: 0.72-3.18) and non-cardiovascular (adjusted HR: 2.25, 95% CI: 0.96-5.28) mortality risk than patients with high CRP(3 months) and low CRP(6 months).


CONCLUSIONS
Single and repeatedly high concentrations of CRP (>10 mg/l) are related to both cardiovascular and non-cardiovascular mortality in dialysis patients. A high CRP concentration, therefore, has implications for the treatment of cardiovascular as well as non-cardiovascular disease.
den Elzen
Wendy P J
WP
Department of Clinical Epidemiology, Leiden University Medical Centre, C9-P, PO Box 9600, 2300 RC Leiden, The Netherlands.
van Manen
Jeannette G
JG
Boeschoten
Elisabeth W
EW
Krediet
Raymond T
RT
Dekker
Friedo W
FW
D002097:C-Reactive Protein / Q000032:analysis*; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009026:Mortality; D011379:Prognosis; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000401:mortality*; D016019:Survival Analysis
D002097:C-Reactive Protein