Association of systemic inflammatory response index with the cardiometabolic multimorbidity among US adults: a population- based study

Background: Chronic inflammation plays an essential role in the occurrence and progression of cardiometabolic diseases (CMDs). We aim to examine the association between a novel inflammatory biomarker systemic inflammatory response index (SIRI) and different cardiometabolic multimorbidity (CMM) status. Methods This is a cross-sectional study that include general participants of National Health and Nutrition Examination Survey (NHANES) database from 1999 to 2018. SIRI was calculated as neutrophil count × lymphocyte count/monocyte count. The cardiometabolic diseases were defined as a series of diseases including diabetes mellitus (DM), heart disease, and stroke. We explored the association of SIRI with outcomes with weighted multivariable logistic regression models weighted restricted cubic spline (RCS). The diagnostic value of SIRI was evaluated using weighted receiver operating curves (ROCs). Results A total of 43,345 participants were enrolled with a mean age of 45.86 years. The weighted prevalence of CMD and CMM was 17.14% and 2.94%, respectively. Compared to those without cardiometabolic disease, the adjusted odds ratios (ORs) (95% confidence interval, CI) for each unit increase in SIRI index were 1.14 (1.09, 1.19) for diabetes mellitus (DM), 1.13 (1.07, 1.19) for heart disease, 1.11 (1.04, 1.19) for stroke, 1.17 (1.12, 1.22) for CMD, and 1.16 (1.10, 1.23) for CMM, according to the weighted multivariable logistic regression. Elevated SIRI level was independently associated with increased cardiometabolic multimorbidity. There was no interaction found in subgroup analysis. According to the ROC analysis, SIRI had a superior diagnostic ability to NLR, PLR, and MLR for CMD (AUC = 0.581) and CMM (AUC = 0.633) Conclusions Elevated level of SIRI was positively associated with the prevalence of DM, coronary artery disease, stroke, CMD, and CMM, suggesting that SIRI could be a potential non-invasive biomarker for CMD and CMM.