Relationship of the Neutrophil-Lymphocyte Ratio with All-Cause and Cardiovascular Mortality in Patients with Diabetic Kidney Disease: A Prospective Cohort Study of NHANES Study.

Background: To investigate the association between the NLR and the risk of all-cause and cardiovascular mortality in US adults with diabetic kidney disease (DKD).

Methods: The data utilized for this analysis were sourced from ten National Health and Nutrition Examination Survey cycles (1999-2018) with mortality data (up to 31 December 2019) via linkage to the National Death Index. The optimum NLR threshold for predicting survival outcomes was determined through the maximally selected rank statistics. Restricted cubic spline (RCS), weighted Cox proportional hazard regression, stratified analyses, and time-dependent receiver-operating characteristic curve (ROC) were employed to delineate the prospective correlations of the NLR with both all-cause and cardiovascular mortality.

Results: In this investigation, a cohort comprising 2581 patients diagnosed with DKD was examined, encompassing 624 individuals with a higher NLR (≥3.07) and 1957 subjects with a lower NLR (<3.07). Over a median follow-up of 79 months (interquartile range, 44-128 months), 1103 deaths occurred, including 397 from cardiovascular causes and 706 from non-cardiovascular causes. The RCS analysis elucidated the positive linear correlation (both nonlinear > 0.05). In the multivariable analyses, each one-unit increase in the NLR value was correlated with a 51% increased risk of all-cause mortality (1.51(1.28, 1.77)) and a 71% increased risk of cardiovascular mortality (1.71(1.32, 2.21)). The results were largely consistent across stratified analyses encompassing variables such as age, sex, race/ethnicity, marital status, family income, education levels, BMI, drinking status, smoking status, hypertension, CVD, and anti-infective drugs ( for interaction >0.05 for all). Time-dependent ROC analyses underscored the NLR's credible predictive efficacy for both short-term and extended durations in forecasting both all-cause and cardiovascular mortality.

Conclusion: The findings emphasize the promising use of the NLR in stratifying and prognosticating the risk of mortality in DKD in clinical practice.