Association between AISI and mortality among individuals with abdominal obesity: A cohort study

This study examines the association between the aggregate index of systemic inflammation (AISI) and mortality among individuals with abdominal obesity, aiming to provide a scientific basis for accurate identification of high-risk individuals and the implementation of early interventions. This study utilized data from the National Health and Nutrition Examination Survey (NHANES) 1999–2016 to include adults with abdominal obesity. The AISI was calculated as (neutrophil count × platelet count × monocyte count)/lymphocyte count. Participants were linked to the National Death Index to determine vital status, with mortality follow-up extending through December 31, 2019. The association between the AISI and mortality risk in individuals with abdominal obesity was examined through Kaplan–Meier survival analysis, weighted Cox proportional hazards regression, subgroup stratification, and restricted cubic spline modeling. This cohort study enrolled 15,839 adult participants with abdominal obesity. During a median follow-up of 119 months, 2223 deaths were recorded. Kaplan–Meier survival analysis showed that elevated levels of the AISI were significantly associated with reduced survival probability. After comprehensive adjustment for multiple potential confounders, multivariate Cox proportional hazards regression revealed a significant positive association between AISI levels and all-cause mortality risk in individuals with abdominal obesity. When AISI was treated as a continuous variable, each 1-unit increase was associated with a 1% higher risk of death (fully adjusted HR = 1.01, 95% CI: 1.01–1.01, P < .001). When dichotomized at the median, the high AISI group exhibited a 16% increased risk of mortality compared to the low AISI group (fully adjusted HR = 1.16, 95% CI: 1.04–1.30, P = .010). Restricted cubic spline analysis confirmed a statistically significant linear relationship ( P for overall < .001; P for nonlinearity = .192). Subgroup analyses indicated heterogeneity in this association across marital status subgroups (interaction P = .017). This study demonstrates that elevated AISI levels are associated with increased mortality risk among individuals with abdominal obesity. These findings underscore the value of AISI as a prognostic indicator for mortality in this at-risk population. The integration of AISI into clinical inflammatory assessment frameworks may facilitate the establishment of dynamic surveillance strategies for identifying and monitoring high-risk individuals.