Association of Monocyte-Lymphocyte Ratio with Cardiovascular Events and All-Cause Mortality in Patients Undergoing...

Elevated monocyte to lymphocyte ratio (MLR) represents a pro-inflammatory immune microenvironment and has been associated with poor clinical outcomes such as cardiovascular disease. However, little is known about its association with outcomes among patients on hemodialysis.

In a nationwide prospective cohort of 952 patients receiving maintenance hemodialysis from 2011-2013, we examined the association of baseline MLR with subsequent risk of cardiovascular events (cardiovascular-related hospitalization and cardiovascular death) and all-cause mortality, using multivariable Cox proportional-hazards models with adjustment for potential confounders. We also examined the mediation effect of inflammatory markers on the association between MLR and cardiovascular events and all-cause mortality, respectively.

Overall, patients were 60.1 ± 13.4 years old; 53.3% were male; 39.7% were African American; and 56.9% were diabetic. The median dialysis vintage was 3.1 years. During a median follow-up of 2.1 years, 184 and 207 cases experienced cardiovascular events and all-cause death, respectively. A higher MLR was incrementally associated with higher risk of cardiovascular events and all-cause mortality. The multivariable-adjusted hazard ratios (95% confidence interval) of cardiovascular events and all-cause mortality for 0.1-unit increase in MLR were 1.22 (1.09-1.37) and 1.18 (1.07-1.30), respectively. There was a modest but significant mediation effect of plasma interleukin-6 (IL-6) on the association between MLR and cardiovascular events (28.2%) and all-cause mortality (24.1%).

A higher MLR was independently associated with higher risk of cardiovascular events and all-cause mortality in patients on hemodialysis. Our findings suggest the potential of MLR as a simple, cost-effective prognostic biomarker and support IL-6-targeted therapeutic interventions to improve clinical outcomes in patients with ESKD.