Association between NPAR and diabetic kidney disease: Insights from NHANES 2017 to 2020

The neutrophil-to-albumin ratio (NPAR) has been identified as an emerging biomarker for systemic inflammation. However, its association with diabetic kidney disease (DKD) remains unclear. This study aims to evaluate the relationship between NPAR and DKD using data from the National Health and Nutrition Examination Survey 2017 to 2020. A total of 8031 participants were included after excluding subjects under 18 years and those with missing data on DKD or NPAR. Participants were categorized based on DKD status. Weighted logistic regression and restricted cubic spline analyses were performed to investigate the association between NPAR and DKD. Higher NPAR levels were significantly associated with increased DKD risk (odds ratio = 2.11, 95% confidence interval: 1.60-2.80, P < .001 in Model 3, adjusted for demographic and clinical covariates). Subgroup analysis indicated that the association was consistent across age, gender, and body mass index categories. Restricted cubic spline analysis suggested a linear relationship between NPAR and DKD risk (P-overall < .001, P-nonlinear = .174). The area under the curve for NPAR predicting DKD was 0.652. Elevated NPAR is associated with an increased prevalence of DKD. However, due to the cross-sectional nature of the study, causality cannot be inferred. These findings highlight the potential of NPAR as an inflammatory marker for DKD risk stratification.