Associations of Pan-immune-inflammation Value with Asthma and Mortality in Adults: A Cross Sectional Analysis of the NHANES 1999–2018

Background The pan-immune-inflammation value (PIV), calculated as (neutrophil count × platelet count × monocyte count) / lymphocyte count, has been linked to outcomes in various diseases, but its role in asthma remains unclear. We aimed to assess the associations of PIV with asthma prevalence and all-cause mortality in a nationally representative cohort. Methods Data were obtained from the National Health and Nutrition Examination Survey (NHANES) 1999–2018. Logistic regression models was used to examine the association between PIV and asthma prevalence, and Cox proportional hazards models were applied to evaluate hazard ratios (HRs) for mortality in asthmatic participants. Restricted cubic splines assessed nonlinear associations, and Kaplan–Meier curves compared survival across PIV tertiles. Results A total of 38,395 participants were included, of whom 5,220 reported physician-diagnosed asthma. According to the multivariable-adjusted models, PIV was not significantly associated with asthma prevalence. However, among 5,212 asthmatic individuals with follow-up mortality data, higher PIV levels were associated with increased all-cause mortality. Compared to the lowest PIV tertile, the highest tertile showed a significantly greater risk of death (adjusted HR = 1.39; 95% CI: 1.15–1.68). A J-shaped dose–response relationship between PIV and mortality risk was observed. Kaplan–Meier curves confirmed the increased cumulative mortality in the highest PIV tertile. Conclusions Our study demonstrated that higher PIV levels were associated with an increased all-cause mortality among individuals with asthma, although no significant association was observed with asthma prevalence. Specifically, the association between PIV and all-cause mortality in asthma is non-linear, characterized by a J-shaped curve with a distinct threshold. Consequently, a higher PIV level may identify a high-risk inflammatory state among asthmatic patients, for whom intensified monitoring and management of systemic comorbidities could be beneficial. However, further well-designed prospective studies are warranted to validate and expand these findings.