Globally, stroke is a major public health issue with high disability rates. This cohort study utilized data from NHANES 2005–2018 and, to the best of our knowledge, is the first report examining the connection between NPS levels and stroke. The study elaborates on the relationships between nutrition, inflammation, and stroke, as well as the risk of all-cause mortality in stroke patients, further underscoring the importance of assessing nutritional and inflammatory markers in stroke patients. Our findings indicate that stroke patients have higher NPS levels compared to those without stroke. After adjusting for relevant factors, we found a significant positive association between NPS and all-cause mortality in stroke patients.
Malnutrition is associated with poor prognosis in stroke patients17,18 and can trigger systemic inflammation19, which increases the risk of stroke20 and worsens outcomes21. Conversely, inflammation exacerbates malnutrition, creating a vicious cycle22. Clinically, various biomarkers are used to assess the nutritional status of stroke patients7. Serum albumin levels, a common indicator of nutritional status, are closely associated with increased stroke risk23,24. Total cholesterol levels are another nutritional status indicator; their relationship with stroke remains uncertain25, with total cholesterol possibly positively associated with ischemic stroke and negatively associated with hemorrhagic stroke risk26–28.
On the other hand, systemic inflammation exacerbates atherosclerosis, thereby increasing the risk of stroke. Post-stroke inflammation can lead to significant long-term sequelae29. NLR and LMR are potential novel biomarkers of systemic inflammation and serve as good predictors in ischemic stroke patients30,31. Inflammatory cytokines exacerbate malnutrition in stroke patients by increasing metabolic demands, reducing appetite, affecting digestion and absorption, and breaking down muscle and fat32,33. Studies have shown that low albumin levels are correlated with elevated levels of inflammatory markers, further increasing stroke risk34,35.
Elevated inflammatory markers are associated with poorer nutritional status and higher mortality rates in stroke patients36. This bidirectional relationship between inflammation and malnutrition worsens the prognosis of stroke patients, making it crucial to find indicators that can assess both nutritional status and systemic inflammation. NPS uses albumin, total cholesterol, NLR, and LMR to calculate a score, reflecting systemic inflammation and nutritional status, and is associated with the prognosis of various diseases37–39. Although research on NPS mainly focuses on tumor-related diseases, it has been applied in various non-tumor diseases40,41. In our study, We found that stroke patients have higher NPS levels, and with 5.94 years of all-cause mortality follow-up data, Cox regression analysis found that the Naples Prognostic Score was significantly associated with all-cause mortality in adults stroke patients.
Our study has the following strengths, first, we used a nationally representative and relatively large sample to investigate the significantly increased NPS levels in adult stroke patients and further elucidate the relationship between NPS and stroke mortality, enhancing the generalizability and credibility of our findings. Secondly, we meticulously adjusted our analyses for key factors affecting stroke, thereby improving the reliability and scientific rigor of our results. We included an average of 5.94 years of follow-up data, elucidating the correlation between NPS and all-cause mortality in stroke patients. Third, NPS considers the dual impact of nutritional status and systemic inflammation, making it a more comprehensive indicator of a patient's health status and disease risk compared to individual nutritional or inflammatory markers.
Despite the significant advantages of our study, there are some limitations that must be acknowledged, aside from the lack of detailed neurological function scores in NHANES, which prevented us from assessing the impact of NPS on stroke-related disability and quality of life. NHANES relies on patient self-reporting, which may introduce recall bias and affect data accuracy. Secondly, although we controlled for various potential confounding factors, unmeasured confounders may still influence our analysis. For instance, unaccounted variables such as dietary habits and genetic factors could be potential confounders. Additionally, despite the nationwide scope of this study, the data primarily derive from the US population, limiting the representation of economically underdeveloped countries. This restricts the global applicability of our findings. Therefore, when interpreting and applying the results of this study, these limitations should be fully considered to more accurately understand the significance and impact of the research. Going forward, global clinical investigations are necessary to validate our conclusions and assess their applicability across different populations and regions.