C-reactive protein-to-albumin ratio and six-month mortality in incident hemodialysis patients

Abstract

Background: The first few months of hemodialysis (HD) are associated with a higher risk of mortality. Protein-energy malnutrition is a demonstrated major risk factor for mortality in this population. The C-Reactive Protein to Albumin ratio (CAR) has also been associated with increased mortality risk. The aim of this study was to determine the predictive value of CAR for six-month mortality in incident HD patients.

Methods: Retrospective analysis of incident HD patients between January 2014 and December 2019. CAR was calculated at the start of HD. We analyzed six-month mortality. A Cox regression was performed to predict six-month mortality and the discriminatory ability of CAR was determined using the receiver operating characteristic (ROC) curve.

Results: A total of 787 patients were analyzed (mean age 68.34 ± 15.5 years and 60.6% male). The 6-month mortality was 13.8% (n = 109). Patients who died were significantly older (p < 0.001), had more cardiovascular disease (p = 0.010), had central venous catheter at the start of HD (p < 0.001), lower parathyroid hormone (PTH) level (p = 0.014) and higher CAR (p = 0.015). The AUC for mortality prediction was 0.706 (95% CI (0.65-0.76), p < 0.001). The optimal CAR cutoff was ≥0.5, HR 5.36 (95% CI 3.21-8.96, p < 0.001).

Conclusion: We demonstrated that higher CAR was significantly associated with a higher mortality risk in the first six months of HD, highlighting the prognostic importance of malnutrition and inflammation in patients starting chronic HD.

Keywords: Hemodialysis; inflammation; malnutrition; mortality.

Figure 1.

Flow-chart of patient selection.

Figure 2.

Receiver operating curve of C-reactive protein, albumin, and C-reactive protein-to-albumin ratio to predict six-month mortality.

Figure 3.

Cumulative survival of patients who started maintenance HD according to CAR ≥ 0.5.