Association between neutrophil percentage-to-albumin ratio and sleep disorders risk: insights from a large US...

Sleep disorders are intricately associated with inflammation and metabolic dysregulation. Unlike C-reactive protein (CRP), which solely reflects inflammation, the neutrophil percentage-to-albumin ratio (NPAR) integrates both inflammatory and nutritional status, offering a more comprehensive biomarker for sleep disorders. However, the mechanisms linking NPAR to sleep disorders remain unclear. This study aimed to clarify the role of NPAR in sleep disorders and explore its potential mechanisms and implications.

We analyzed data from 14,297 participants in the National Health and Nutrition Examination Survey (NHANES, 2005-2018), including 3909 individuals diagnosed with sleep disorders. Weighted logistic regression was used to assess the association between NPAR and sleep disorders. The XGBoost model was applied to identify key associated factors, and a restricted cubic spline (RCS) model was used to evaluate the dose-response relationship. Mediation analysis was conducted to examine the effects of weight-related indicators-relative fat mass (RFM) and weight-adjusted waist index (WWI).

NPAR was significantly higher in participants with sleep disorders than in controls (14.11 ± 2.76 vs. 13.75 ± 2.58, P < 0.001). Each unit increase in NPAR was associated with a 3.6% higher risk of sleep disorders (OR = 1.036, 95% CI: 1.022-1.051). Participants in the highest NPAR quartile had a 33.8% increased risk (OR = 1.338, 95% CI: 1.201-1.490). The XGBoost model identified NPAR as one of the top five key factors (SHAP value = 0.00891). Observational analyses revealed that NPAR was positively correlated with white blood cells, red cell distribution width, creatinine, RFM, and WWI, and negatively correlated with red blood cells, eosinophils, albumin, and total protein. Mediation analysis showed that WWI (51.04%), RFM (48.6%), white blood cells (24.93%), and red cell distribution width (14.91%) partially mediated the association between NPAR and sleep disorders.

NPAR may serve as a novel biomarker for assessing sleep disorder risk and could help elucidate mechanisms linking inflammation and metabolic dysregulation to sleep disturbances.