Association between novel inflammatory biomarkers SII, SIRI, and obesity in sedentary adults: NHANES 2007-2020

Sedentary behavior is prevalent in modern society and is closely associated with various chronic diseases, including obesity. The Systemic Immune-Inflammation Index (SII) and the Systemic Inflammation Response Index (SIRI), as novel inflammatory biomarkers, may play an important role in predicting obesity risk. This study utilized data from the 2007-2020 National Health and Nutrition Examination Survey (NHANES) to analyze the relationship between sedentary behavior, SII, SIRI, and obesity through multivariable logistic regression models. The study found that sedentary time was significantly associated with levels of SII and SIRI. In participants with sedentary time (ST) ≥ 5 h, the median values of SII and SIRI were 453.14 and 0.99, respectively, compared to participants with sedentary time < 5 h, whose median values of SII and SIRI were 437.82 and 0.91. The AUC value of lnSII was 0.70, indicating a high accuracy in predicting obesity risk, while the AUC value of SIRI was 0.55. Additionally, the proportion of obesity in the group with sedentary time ≥ 5 h was significantly higher than that in the group with sedentary time < 5 h, further emphasizing the association between sedentary behavior and obesity.This study demonstrates that sedentary behavior is associated with obesity risk through its impact on SII and SIRI levels, highlighting the potential importance of lifestyle changes, particularly reducing sedentary time, in controlling obesity. These findings support the application of SII and SIRI in obesity risk assessment, and future research is recommended to explore the potential of these markers in different populations.