Significance of high C‐reactive protein levels in pre‐dialysis patients

AbstractBackground. An elevated serum C-reactive protein(CRP) has been shown to be strongly predictive ofmorbidity and mortality in dialysis patients. However,the significance of high CRP levels in the pre-dialysisperiod has not been studied extensively. The aim of ourstudy was to analyse the evolution of our pre-dialysispopulation according to their basal levels of CRP.Methods. A cohort of 66 pre-dialysis patients wasfollowed for 1 year, after initial determination ofserum CRP. The evolution of blood pressure (BP)control, CRP levels, nutritional data (body mass index,serum albumin, prealbumin, transferrin, cholesterol),proteinuria, calcium-phosphorus product, bicarbonate,haemoglobin (Hb), the weekly dose of erythropoietin(Epo)ukg body weight, and the HbuEpo dose ratio weremeasured and compared between patients with high()6mgul) or low (-6mgul) CRP levels at baseline. Thedecline in renal function, hospitalization, and deathalso were measured and compared between the twogroups.Results. At baseline, 23 patients (35%) showed high()6mgul) CRP levels. CRP was higher in patients witha previous history of cardiovascular disease (P-0.01),as well as in patients in whom ischaemic nephropathyor nephrosclerosis was the cause of end-stage renaldisease (P-0.01). There were no differences betweendiabetic and non-diabetic patients. During the studyperiod, patients with higher CRP levels at baselinemaintained higher levels (P-0.001). During thisperiod, these patients showed lower (P-0.05) albuminconcentration, higher bicarbonate levels, lower Hbconcentration, and lower HbuEpo ratio and neededhigher Epo doses. There were no differences in systolicBP, the degree of proteinuria, and the decline in renalfunction between groups; diastolic BP was lower inpatients with high CRP levels. Hospitalization washigher (P-0.005) in this group. Only one patient died.Conclusions. The prevalence of inflammation is highin pre-dialysis patients. High serum CRP levels predicta constant inflammatory state on follow-up. As occursin dialysis patients, pre-dialysis inflammation predictslower serum albumin concentration, poorer responseto Epo, and a higher hospitalization rate. The declinein renal function does not seem to be related to theinflammatory state. Mortality was not affected onshort-term follow-up.Keywords: erythropoietin response; hospitalization;hypoalbuminaemia; inflammation; pre-dialysis