Association of neutrophil-to-lymphocyte ratio with all-cause and cardiovascular mortality in CVD patients with diabetes or pre-diabetes

The neutrophil-to-lymphocyte ratio (NLR), a simple marker of systemic inflammation, is crucial in the progression of cardiovascular diseases (CVD). Its predictive value for all-cause and cardiovascular mortality in CVD patients with diabetes or pre-diabetes remains unclear. We analyzed 3,780 CVD patients with diabetes or pre-diabetes from the National Health and Nutrition Examination Survey (2001-2018). Kaplan-Meier survival curves, weighted Cox proportional hazards models, and restricted cubic spline (RCS) analyses were used to assess the relationship between NLR and mortality risk. RCS revealed a U-shaped association between NLR and all-cause mortality, with an inflection point at 1.776. For NLR < 1.776, the risk of all-cause mortality decreased by 13% per unit increase in NLR (HR: 0.87, 95% CI: 0.76-0.98). For NLR ≥ 1.776, the risk increased by 15% per unit increase (HR: 1.15, 95% CI: 1.10-1.26). A positive linear association was found between NLR and cardiovascular mortality, with a 17% increase in risk per unit increase in NLR (HR: 1.17, 95% CI: 1.10-1.25). No significant interactions were observed in stratified analyses. Our study revealed the U-shaped relationship between NLR and all-cause mortality, and a positive linear relationship with cardiovascular mortality in CVD patients with diabetes or pre-diabetes.