Background. An elevated serum C‐reactive protein (CRP) has been shown to be strongly predictive of morbidity and mortality in dialysis patients. However, the significance of high CRP levels in the pre‐dialysis period has not been studied extensively. The aim of our study was to analyse the evolution of our pre‐dialysis population according to their basal levels of CRP.
Methods. A cohort of 66 pre‐dialysis patients was followed for 1 year, after initial determination of serum 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)/kg body weight, and the Hb/Epo dose ratio were measured and compared between patients with high (>6 mg/l) or low (<6 mg/l) CRP levels at baseline. The decline in renal function, hospitalization, and death also were measured and compared between the two groups.
Results. At baseline, 23 patients (35%) showed high (>6 mg/l) CRP levels. CRP was higher in patients with a previous history of cardiovascular disease (P<0.01), as well as in patients in whom ischaemic nephropathy or nephrosclerosis was the cause of end‐stage renal disease (P<0.01). There were no differences between diabetic and non‐diabetic patients. During the study period, patients with higher CRP levels at baseline maintained higher levels (P<0.001). During this period, these patients showed lower (P<0.05) albumin concentration, higher bicarbonate levels, lower Hb concentration, and lower Hb/Epo ratio and needed higher Epo doses. There were no differences in systolic BP, the degree of proteinuria, and the decline in renal function between groups; diastolic BP was lower in patients with high CRP levels. Hospitalization was higher (P<0.005) in this group. Only one patient died.
Conclusions. The prevalence of inflammation is high in pre‐dialysis patients. High serum CRP levels predict a constant inflammatory state on follow‐up. As occurs in dialysis patients, pre‐dialysis inflammation predicts lower serum albumin concentration, poorer response to Epo, and a higher hospitalization rate. The decline in renal function does not seem to be related to the inflammatory state. Mortality was not affected on short‐term follow‐up.
Keywords: erythropoietin response; hospitalization; hypoalbuminaemia; inflammation; pre‐dialysis
Journal Article. 3247 words.
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