Association between Neutrophil-Percentage-to-Albumin Ratio and Kidney Stones: A Cross-Sectional Study Using NHANES Data

Introduction: Our goal was to explore the potential association between the neutrophil-percentage-to-albumin-ratio (NPAR) and kidney stones. Methods: This study utilized data from the National Health and Nutrition Examination Survey (NHANES), collected between 2007 and 2018. We employed multiple logistic regression models and smooth curve fitting to investigate the relationship between NPAR and other inflammatory biomarkers, including the systemic immune inflammation index (SII), platelet/lymphocyte ratio (PLR), and neutrophil/lymphocyte ratio (NLR), in relation to kidney stones. Independent relationships between these factors were assessed. Subgroup analysis revealed associations based on different population types. The study also evaluated the predictive ability of various inflammation markers in assessing the likelihood of developing kidney stones. Results: A total of 17,258 subjects were recruited, with a prevalence of kidney stones at 8.9%. Through multiple logistic regression models and smooth curve fitting, we found that NPAR was associated with other inflammatory biomarkers (SII, PLR, NLR) and the presence of kidney stones. A nonlinear relationship with a saturation effect was observed, characterized by an L-shaped curve. The inflection points identified were 17.66, 1.06, 78.26, and 3.36. A positive correlation was noted on the left side of the inflection point, while a negative correlation was observed on the right side. In subgroup analysis, male participants and those with universal high school education exhibited a significantly increased incidence of kidney stones (P < 0.05). In ROC analysis, NPAR demonstrated the best discriminatory power and accuracy in predicting kidney stones compared to other inflammatory markers. Discussion: NPAR may serve as a superior biomarker of inflammation relative to other inflammatory biomarkers (SII, PLR, NLR). U.S. adults with elevated levels of NPAR, SII, PLR, and NLR should be cognizant of potential risks to kidney health.