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The Association Between PIV and Mortality in US Stroke Survivors: A NHANES 1999-2018 Retrospective Cohort Study
Ying Lyu1, Yuhui Yin1, Junfang Ma1
1Department of Neurology and Psychiatry, Emergency and Critical Care Medical Center, Beijing Shijitan Hospital Capital Medical University Beijing China.
Background And Aims:
Stroke is a leading cause of mortality and disability worldwide. The pan-immune-inflammation value (PIV) has emerged as a composite marker of systemic immune-inflammatory status. We aimed to investigate the association of PIV with mortality in US adults with a history of stroke.
Methods:
We analyzed 1948 participants in the 1999-2018 National Health and Nutrition Examination Survey (NHANES). Baseline PIV was calculated from routine blood counts as (neutrophils × platelets × monocytes ÷ lymphocytes). Mortality outcomes were ascertained through linked death records. A generalized additive model incorporating restricted cubic splines was employed to characterize the dose-response relationship between PIV and mortality risk. When statistically significant nonlinearity was detected in the exposure-outcome association, a two-piecewise Cox proportional hazards model was applied to estimate hazard ratios for each segment.
Results:
Among 1948 participants, 904 deaths (46.4%) occurred over a median follow-up of 75 months; the mean age was 66.8 ± 13.3 years. PIV exhibited a statistically significant J-shaped association with all-cause mortality (p = 0.001), with an inflection point ≈ 133.8. Below this threshold, each 100-unit increase in PIV was associated with a 53% reduction in mortality hazard (HR: 0.47; 95% confidence interval (CI): 0.30-0.75; p < 0.01). Above it, each 100-unit increase corresponded to a 9% increase in mortality hazard (HR: 1.09; 95% CI: 1.05-1.12; p < 0.001). In categorical analyses, using PIV 180-220 as the reference range, participants with PIV > 220 had a significantly higher risk of all-cause mortality (HR: 1.47; 95% CI: 1.14-1.89; p = 0.002).
Conclusion:
Among US stroke survivors, both abnormally low and high PIV levels were associated with an increased risk of mortality in a J-shaped pattern. As a composite index derived from routine blood counts, PIV may serve as an accessible candidate indicator for risk assessment in stroke survivors, though prospective studies are needed to validate these findings and elucidate the underlying mechanisms.
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