Comorbidity and acute clinical events as determinants of C-reactive protein variation in hemodialysis patients: implications for patient survival.
BACKGROUND
Patients with chronic kidney disease stage 5 have high comorbidity and are prone to inflammation that may contribute to the high cardiovascular mortality risk.


METHODS
Three-month observational cohort study of prevalent hemodialysis patients.


METHODS
228 hemodialysis patients (44% women) were included, median age of 66 years, median time on dialysis therapy of 29 months.


METHODS
In part 1, comorbidity and intercurrent illness were predictors and C-reactive protein (CRP) level was the outcome. In part 2, serial CRP values were predictors and survival was the outcome.


METHODS
High-sensitivity CRP was measured weekly and interleukin 6 (IL-6), tumor necrosis factor alpha, and IL-10 were measured monthly. Data for comorbidity were collected from patient records to calculate Davies comorbidity score, and self-reported clinical events were recorded weekly.


RESULTS
Median baseline CRP level was 6.7 mg/L (25th to 75th percentiles, 2.5 to 21 mg/L). Baseline CRP level correlated with time-averaged CRP (Spearman rho = 0.76) and individual median of serial CRP values (rho = 0.78; both P < 0.001). Part 1: comorbidity score was significantly associated with greater CRP and IL-6 levels. Age, sex, comorbidity, and 7 of 12 clinical events had significant effects on CRP level variation. Part 2: during a mean follow-up of 29 months, 38% of patients died. Median and mean serial CRP levels were associated with a greater hazard ratio for death (1.013; 95% confidence interval, 1.004 to 1.022) and 1.012 (95% confidence interval, 1.004 to 1.020) than baseline, maximum, and minimum CRP values during the study. Other significant covariates were age, Davies risk group, dialysis vintage, and albumin level.


CONCLUSIONS
The study is based on observational data for prevalent dialysis patients.


CONCLUSIONS
Comorbidity and clinical events are strongly associated with inflammation in hemodialysis patients. Despite variability over time, inflammation assessed by using CRP level is a strong predictor of mortality. Serial measurements provide additional information compared with a single measurement.
Snaedal
Sunna
S
Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.
Heimbürger
Olof
O
Qureshi
Abdul Rashid
AR
Danielsson
Anders
A
Wikström
Björn
B
Fellström
Bengt
B
Fehrman-Ekholm
Ingela
I
Carrero
Juan Jesús
JJ
Alvestrand
Anders
A
Stenvinkel
Peter
P
Bárány
Peter
P
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism* / Q000502:physiology; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000401:mortality / Q000628:therapy; D018836:Inflammation Mediators / Q000097:blood / Q000502:physiology*; D007676:Kidney Failure, Chronic / Q000097:blood / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D006435:Renal Dialysis / Q000009:adverse effects*; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome
D015415:Biomarkers; D018836:Inflammation Mediators; D002097:C-Reactive Protein