Elevated systemic immune inflammation level increases the risk of total and cause-specific mortality among patients with chronic kidney disease: a large multi-center longitudinal study

Abstract

Background: Chronic kidney disease (CKD) is inherently a complex immune-inflammatory condition, and heightened inflammation and immune dysfunction are closely related to an increased risk of death. However, evidence regarding the relationship between immune-inflammatory levels and all-cause, cardiovascular, and cancer mortality among patients with CKD is scarce.

Methods: Patients with non-dialysis dependent CKD undergoing coronary angiography (CAG) were included from five Chinese tertiary hospitals. Systemic immune inflammation index (SII) was calculated by multiplying peripheral platelet count with neutrophil-to-lymphocyte ratio, and patients were categorized into four groups by SII quartiles. Cox regression models and competing risk Fine and Gray models were used to examining the relationships between SII levels and all-cause, cardiovascular, and cancer mortality.

Results: A total of the 19,327 patients (68.8 ± 10.03 years, female 32.0%) were included in this study. During a median follow-up of 4.5 years, 5,174 deaths occurred, including 2,861 cardiovascular deaths and 375 cancer deaths. Controlling for confounders, all-cause mortality (Q2, Q3, Q4: hazard ratio(HR) [95 CI%] = 1.15 [1.06-1.26], 1.30 [1.19-1.42], 1.48 [1.35-1.62], respectively; p for trend < 0.001) and cardiovascular mortality (Q2, Q3, Q4: HR [95 CI%] = 1.16 [1.03-1.31], 1.40 [1.24-1.58], 1.64 [1.44-1.85], respectively; p for trend < 0.001) increased with higher SII levels, and SII levels was related to cancer mortality comparing last quartile to first quartile of SII (Q2, Q3, Q4: HR [95 CI%] = 1.12 [0.83-1.52], 1.22 [0.90-1.67], 1.50 [1.09-2.08], respectively; p for trend < 0.001).

Conclusion: Elevated immune inflammation level on admission was an independent risk factor for all-cause, cardiovascular, and cancer mortality among CKD patients. Further research is needed to validate the predictive value of SII for mortality risk among CKD patients.

Keywords: All-cause mortality; Cancer mortality; Cardiovascular mortality; Chronic kidney disease; Systemic immune inflammation index.