Serum C-reactive Protein Level Is Associated with Renal Function and It Affects Echocardiographic Cardiovascular Disease in Pre-Dialysis Patients

Abstract

Background: Relevance of serum CRP for morbidity and mortality in pre-dialysis patients has not been assessed extensively. The aim of this study was to determine the incidence of elevated serum CRP in pre-dialysis patients and to identify the factors that associate with serum CRP. We were also evaluated the effects of serum CRP on cardiovascular disease, anemia, and nutritional markers. Methods: One hundred and eight pre-dialysis patients with a mean creatinine clearance (CrCl) of 30.1 ml/min were included in the study. Data collected from each patient included demographics, co-morbidity, medications, blood pressures, blood biochemistry including serum CRP, renal function, and echocardiography. Results: Serum CRP was elevated (>5 mg/l) in 43 patients (39.8%). There was a negative correlation between serum CRP and CrCl (r = –0.370, p < 0.001). CrCl was the unique independent factor affecting serum CRP. Serum CRP was an independent factor affecting left ventricular mass index, fractional shortening, serum albumin and hematocrit in multivariate analyses. Conclusions: Prevalence of elevated serum CRP in pre-dialysis patients is high. Reduced renal clearance of CRP and/or cytokines may contribute to the inflammatory status. Elevated serum CRP is an important cause of morbidity in pre-dialysis patients.

Serum CRP Levels in Pre-Dialysis Patients

“…[16] In our study, a statistical negative correlation was found between the serum CRP levels and the patients' negative acute phase proteins, while positive acute phase proteins were positively correlated with CRP levels. This was similar to the findings of other studies [14,16,20] ; however, the negative correlation between serum CRP and serum transferrin was only reported in the study of Ates et al [20] Contrary to Ortega's study, [16] Ates et al [20] reported a highly positive correlation between serum CRP and ferritin. Stenvinkel et al [15] reported the correlation between serum CRP and fibrinogen levels in 109 predialysis patients.…”

“…[29] A significant negative correlation between serum CRP and hemoglobin levels of pre-dialysis patients was reported in the studies of Ortega [16] and Ates. [20] However, in the present study, the serum CRP and hemoglobin levels were not correlated. It is possible that a more acute inflammation is required for any remarkable decrease in serum hemoglobin occurrence.…”

“…The positive correlation between creatinine clearance, cytokines, and their soluble receivers is proved in various stages of renal failure. [14,22] Creatinine clearance is introduced as an independent factor influencing the serum CRP level of pre-dialysis patients [20] ; however, the abnormal distribution of CRP levels in these patients, like the present study, indicates renal dysfunction is not solely responsible for inflammatory responses. As a result, other factors, including infections of teeth and gum as well as Chlamydia pneumonia, often accompanied with renal failure may activate the acute phase response.…”

“…Indeed, the inflammatory process and the elevated serum CRP levels in patients with chronic renal failure reduce GFR. [1,7] Ates and Panichi [14,20] also found a negative correlation between the serum CRP and GRF levels; however, the said correlation was not found in other studies. [16] The acute phase response is set by several pre-inflammatory cytokines (IL-6, TNF-α, INF-β, INF-γ, IL-1).…”

“…Similar to other studies, our study revealed no statistically meaningful difference between the amounts of triglyceride, cholesterol, LDL, and HDL in either of the groups. [15,16,20] Anemia is an independent risk factor for cardiovascular diseases and general mortality in patients with chronic renal failure. [28] The activated acute phase response in dialysis patients results in anemia and resistance to erythropoietin; this may be through several potential mechanisms, including suppressing erythropoiesis in the bone marrow, reducing the secretion of erythropoietin, GI bleeding, and disorders in iron metabolism.…”