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

Abstract

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 P > 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 (P 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.

Keywords:

• neutrophil–lymphocyte ratio
• diabetic kidney disease
• predictor
• mortality
• cohort study

Data Sharing Statement

The National Health and Nutrition Examination Survey dataset is publicly available at the National Center for Health Statistics of the Centers for Disease Control and Prevention (https://www.cdc.gov/nchs/nhanes/index.htm).

Ethics Approval and Informed Consent

The NHANES 1999–2018 was approved by the NCHS Research Ethics Review Board (Continuation of Protocol #1999–2018), and each participant signed the written informed consent.

Acknowledgments

We thank the NHANES participants and staff for their contributions. We also thank Zhang Jing, Second Department of Infectious Disease, Shanghai Fifth People’s Hospital, Fudan University, for his work on the NHANES database. His outstanding work, nhanesR package, and webpage make it easier for us to explore the NHANES database.

Disclosure

The authors declare that they have no competing interests in this work.