Monocyte-to-lymphocyte ratio predicts mortality and cardiovascular mortality in the general population.

Background: Systemic chronic inflammation (SCI) is closely involved in the pathogenesis of many diseases. This study aims to investigate the association between MLR with mortality and cardiovascular disease (CVD) mortality in US adults.

Methods: 35,813 adults were enrolled from the 1999-2014 National Health and Nutrition Examination Survey (NHANES) cycle. Individuals were categorized according to MLR tertiles and followed until 31 December 2019. Kaplan-Meier plots and log-rank tests were utilized to explore survival differences among the MLR tertiles. Adjusted multivariable Cox analysis was employed to investigate the relationship of MLR with mortality and CVD mortality. Restricted cubic spline and subgroup analysis were further used to discern non-linear relationship and the relationship in categories.

Results: During a median follow-up of 134 months, 5865 (16.4%) all-cause deaths and 1602 (4.5%) cardiovascular deaths occurred. Kaplan-Meier plots revealed significant differences in all-cause and cardiovascular mortality among the MLR tertiles. In the fully-adjusted Cox regression model, individuals in the highest tertile of MLR had higher risk of mortality (HR = 1.26, 95% CI: 1.17-1.35) and CVD mortality (HR = 1.41, HR, 95% CI: 1.23-1.62) than those in the lowest tertile. The restricted cubic spline exhibited a J-shaped relationship between MLR with mortality and CVD mortality (P for non-linearity <0.001). The further subgroup analysis demonstrated a robust trend across categories.

Conclusion: Our study demonstrated that increased baseline MLR was positively associated with a higher risk of death in US adults. MLR was a strong independent predictor of mortality and CVD mortality in the general population.