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.