AUTHOR=Chen Yongze , Huang Ruixian , Mai Zhenhua , Chen Hao , Zhang Jingjing , Zhao Le , Yang Zihua , Yu Haibing , Kong Danli , Ding Yuanlin 

TITLE=Association between systemic immune-inflammatory index and diabetes mellitus: mediation analysis involving obesity indicators in the NHANES

JOURNAL=Frontiers in Public Health

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2023.1331159

DOI=10.3389/fpubh.2023.1331159

ISSN=2296-2565

ABSTRACT=<sec id="sec1"><title>Background</title><p>Inflammation and obesity have been widely recognized to play a key role in Diabetes mellitus (DM), and there exists a complex interplay between them. We aimed to clarify the relationship between inflammation and DM, as well as the mediating role of obesity in the relationship.</p></sec><sec id="sec2"><title>Methods</title><p>Based on the National Health and Nutrition Examination Survey (NHANES) 2005–2018. Univariate analyses of continuous and categorical variables were performed using <italic>t</italic>-test, linear regression, and <italic>χ</italic>2 test, respectively. Logistic regression was used to analyze the relationship between Systemic Immune-Inflammatory Index (SII) or natural logarithm (Ln)-SII and DM in three different models. Mediation analysis was used to determine whether four obesity indicators, including body mass index (BMI), waist circumference (WC), visceral adiposity index (VAI) and lipid accumulation product index (LAP), mediated the relationship between SII and DM.</p></sec><sec id="sec3"><title>Results</title><p>A total of 9,301 participants were included, and the levels of SII and obesity indicators (BMI, WC, LAP, and VAI) were higher in individuals with DM (<italic>p</italic> &lt; 0.001). In all three models, SII and Ln-SII demonstrated a positive correlation with the risk of DM and a significant dose–response relationship was found (<italic>p</italic>-trend &lt;0.05). Furthermore, BMI and WC were associated with SII and the risk of DM in all three models (<italic>p</italic> &lt; 0.001). Mediation analysis showed that BMI and WC mediated the relationship between SII with DM, as well as Ln-SII and DM, with respective mediation proportions of 9.34% and 12.14% for SII and 10.23% and 13.67% for Ln-SII (<italic>p</italic> &lt; 0.001).</p></sec><sec id="sec4"><title>Conclusion</title><p>Our findings suggest that increased SII levels were associated with a higher risk of DM, and BMI and WC played a critical mediating role in the relationship between SII and DM.</p></sec>