Weighted characteristics of the study population categorized quartiles of SII.

Weighted characteristics of the study population categorized quartiles of SII.</p

Association between SII CKD.

BackgroundSystemic immune-inflammation index (SII) is a new indicator of inflammation, and chronic kidney disease (CKD) has a connection to inflammation. However, the relationship between SII and CKD is still unsure. The aim of this study was whether there is an association between SII and CKD in the adult US population.MethodsData were from the National Health and Nutrition Examination Survey (NHANES) in 2003–2018, and multivariate logistic regression was used to explore the independent linear association between SII and CKD. Smoothing curves and threshold effect analyses were utilized to describe the nonlinear association between SII and CKD.ResultsThe analysis comprised 40,660 adults in total. After adjusting for a number of factors, we found a positive association between SII and CKD [1.06 (1.04, 1.07)]. In subgroup analysis and interaction tests, this positive correlation showed differences in the age, hypertension, and diabetes strata (p for interactionConclusionsIn the adult US population, our study found a positive association between SII and CKD (inflection point: 2100). The SII can be considered a positive indicator to identify CKD promptly and guide therapy.</div

Weighted characteristics of the study population categorized by CKD status.

Weighted characteristics of the study population categorized by CKD status.</p

Flowchart of participant selection.

NHANES, National Health and Nutrition Examination Survey.</p

Association between SII and 5 stages of CKD.

Model 1: no covariates were adjusted. Model 2: age, gender, and race were adjusted. Model 3: age, gender, race, marital status, education level, income poverty ratio, BMI, abdominal obesity, drinking status, smoking status, hypertension, and diabetes were adjusted. (DOCX)</p

Subgroup analysis for the association between SII and CKD.

Subgroup analysis for the association between SII and CKD.</p

Weighted characteristics of the study population categorized by 5 stages of CKD.

Continuous variables were expressed as mean ± SD, and P-values were calculated by the weighted linear regression model. Categorical variables are shown as percentages: p-values were calculated by weighted chi-square test. BMI, body mass index; SII, systemic immune-inflammation index; CKD: chronic kidney disease. (DOCX)</p

Association between SII and CKD.

BackgroundSystemic immune-inflammation index (SII) is a new indicator of inflammation, and chronic kidney disease (CKD) has a connection to inflammation. However, the relationship between SII and CKD is still unsure. The aim of this study was whether there is an association between SII and CKD in the adult US population.MethodsData were from the National Health and Nutrition Examination Survey (NHANES) in 2003–2018, and multivariate logistic regression was used to explore the independent linear association between SII and CKD. Smoothing curves and threshold effect analyses were utilized to describe the nonlinear association between SII and CKD.ResultsThe analysis comprised 40,660 adults in total. After adjusting for a number of factors, we found a positive association between SII and CKD [1.06 (1.04, 1.07)]. In subgroup analysis and interaction tests, this positive correlation showed differences in the age, hypertension, and diabetes strata (p for interactionConclusionsIn the adult US population, our study found a positive association between SII and CKD (inflection point: 2100). The SII can be considered a positive indicator to identify CKD promptly and guide therapy.</div

STROBE statement—Checklist of items that should be included in reports of observational studies.

STROBE statement—Checklist of items that should be included in reports of observational studies.</p

Threshold effects of SII on CKD analyzed using linear regression models.

Threshold effects of SII on CKD analyzed using linear regression models.</p