Fuzzy role of hyperhomocysteinemia in hemodialysis patients’ mortality

Inflammatory markers as mortality predictors in continuous ambulatory peritoneal dialysis patients

BACKGROUND/AIM

Besides peritonitis, the most common complication, indicators of chronic inflammation are also present in patients treated by peritoneal dialysis. The aim of this study was to analyze the predictive value of inflammatory parameters on mortality of continuous ambulatory peritoneal dialysis (CAPD) patients.

METHODS

Eighty-seven patients (57 males), aged from 30 to 85 [62.92 (10.61)] years who had been treated by a chronic program of CAPD for 3-113 months were analyzed. The basal period lasted 3 months with a follow-up of 30 months. Clinical parameters, dialysis adequacy and laboratory parameters including some inflammatory markers: serum amyloid-A (SAA), high sensitive C-reactive protein (hs-CRP), fibrinogen, erythrocyte sedimentation rate (ESR) and leukocytes were determined for each patient. Cox regression analysis selected the parameters of univariate and multivariate survival analysis.

RESULTS

During the follow-up period, 37 patients (42.5%) died. Univariate analysis selected the following potential mortality predictors (p<0.10): age, months on CAPD, residual urine output, presence of cerebrovascular insult (CVI), KT/V, serum urea and albumin concentrations, SAA, hs-CRP, fibrinogen and ESR. In the multivariate survival analysis four models were created, each with a single inflammatory parameter. In all of these models, besides the age and CVI, inflammatory parameters were the most significant mortality predictors. When the inflammatory markers were analyzed altogether, multivariate analysis established that independent mortality predictors in this group of patients were: SAA, age and CVI.

CONCLUSION

It may be concluded that in this studied group treated by CAPD, SAA was the most significant independent mortality predictor among the analyzed inflammatory markers.

Serum amyloid-A rather than C-reactive protein is a better predictor of mortality in hemodialysis patients

The most frequent cause of death in hemodialysis patients is cardiovascular disease with chronic inflammation being an epidemiologically proved risk factor. Many studies have shown C-reactive protein (CRP) as the strongest predictor of long-term mortality of hemodialysis patients, while other reports have indicated acute phase proteins as potential predictors of the mortality. The present study therefore aimed to evaluate the prevalence of chronic inflammation in hemodialysis patients and the role of acute phase proteins together with lipids and divalent ions for predicting mortality in hemodialysis patients. Chronic inflammation was defined, based on the serum level of high sensitive CRP > 8.4 mg/L and/or serum amyloid-A (SAA) > 8.9 mg/L. Acute phase proteins are defined as one whose plasma concentration increase (positive) or decreases (negative) by at least 25% during inflammation. High sensitive CRP and SAA were positive acute phase proteins measured, while albumin and fetuin-A, a calcification inhibitor, were selected as negative acute phase proteins. This prospective 36-month follow-up study included 130 patients (60 males and 70 females, aged 55.1 +/- 12.9 years) maintained by hemodialysis for 107.2 +/- 54.72 months at a Nephrology Clinic in Belgrade. The prevalence of chronic inflammation was 35.4% (46 patients). During the follow-up period, 24 patients (18.5%) died and 2 patients received transplants. In multivariate analysis, potential independent predictors of mortality in hemodialysis patients are hyperphosphatemia, hypoalbuminemia, and high SAA. Considering that assays for SAA are widely used, we propose that SAA is the best predictor for outcomes of end-stage renal disease.