Association of Neutrophil‐to‐Lymphocyte Ratio With All‐Cause and Cardiovascular Mortality Among Individuals With Depression: A Large‐Scale Cohort Study

BACKGROUND: The relationship between mortality in depressed patients and the neutrophil-to-lymphocyte ratio (NLR) is not well-documented. METHODS: This cohort study, involving 8749 individuals diagnosed with depression, was derived from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. Data on mortality were obtained by linking the cohort database to the National Death Index, with updates available as of December 31, 2019. Various analytical techniques, including Cox proportional hazards models, restricted cubic splines, Kaplan-Meier curves, and subgroup and sensitivity analyses, were employed. RESULTS: During an average follow-up period of 84 months, 1023 participants (11.7%) died, with 271 of these deaths attributed to cardiovascular diseases (CVD). Our analysis demonstrated a positive connection among the NLR as well as mortality risk in all participants. In contrast to participants in the low NLR category (NLR ≤ 3.06), individuals belonging to the high NLR category (NLR > 3.06) exhibited a 64% increased risk of all-cause mortality (hazard ratio [HR] 1.63, 95% confidence interval [CI] 1.36-1.95) and a 144% elevated risk of mortality due to CVD (HR 2.44, 95%CI 1.77-3.36) after multivariate adjustment. The interactions and data stratification supported the credibility of our results. Importantly, we discovered notable interactions within subgroups that were differentiated by age and diabetes. CONCLUSIONS: Elevated levels of the NLR are linked to a heightened risk of mortality from all causes, including CVD, among adults suffering from depression. This correlation is particularly pronounced in younger populations and in individuals who have diabetes.