Stella Bouziana, Konstantinos Tziomalos, Antonis Goulas, Timoleon-Achilleas Vyzantiadis, Maria Papadopoulou, Apostolos Ηatzitolios
Introduction-Aim: The association between peripheral blood haematological indices and acute ischemic stroke severity, in-hospital and long-term outcome is controversial. We aimed to evaluate this relationship and the potential association of haematological indices with serum adipokines levels and systemic inflammation.
Patients and Methods: We prospectively studied 93 patients consecutively hospitalized for acute ischemic stroke (39.8% males, age 79.7±6.3 years). Peripheral blood haematological indices and serum adiponectin, leptin and resistin levels were determined at admission. The haematological indices that were evaluated were total white blood cells count (WBC), absolute neutrophil count (NC), absolute lymphocyte count (LC), absolute monocyte count (MC), red blood cells count (RBC), hemoglobin (Hb), hematocrit (Ht), platelet count (PC), mean platelet volume (MPV) and the ratios MPV/PC (MPR), NC/LC (NLR) and PC/LC (PLR). Stroke severity at admission was evaluated with the National Institutes of Health Stroke Scale (NIHSS). In-hospital outcome was evaluated by dependency rates at discharge and in-hospital mortality. One year after discharge, functional status, incidence of cardiovascular events and all-cause mortality were recorded. Functional status was evaluated with the modified Rankin scale (mRS).
Results: None of the haematological indices predicted stroke severity or in-hospital mortality. However, patients with dependency at discharge had higher WBC (p<0.05) and NC (p<0.05). Independent predictors of dependency at discharge were prior history of acute ischemic stroke [Risk Ratio (RR) 7.55, 95% Confidence Interval (CI) 1.69-33.58, p<0.01], NIHSS score at admission (RR 1.47, 95% CI 1.17-1.84, p<0,001) and serum triglyceride levels (RR 0.98, 95% CI 0.96-0.99, p<0.05). None of the haematological indices predicted cardiovascular events or all-cause mortality during 1-year-follow-up after discharge. However, patients with adverse outcome had higher NC (p<0.05), lower LC (p<0.05) and higher NLR (p<0.05) and PLR (p<0.05). In multivariate analysis, the mRS score at discharge was the only independent predictor of adverse outcome 1 year after discharge (RR 2.78, 95% CI 1.54-5.00, p<0.001). Regarding the correlation of haematological indices with major adipokines, there was a positive correlation of adiponectin levels with NLR (r=0.295, p=0.012) and PLR (r=0.378, p=0.001), while there was a negative correlation with Hb (r=-0.252, p=0.033). The NLR (r=0.277, p=0.019) and PLR (r=0.240, p=0.043) were also positively correlated with high-sensitivity C-reactive protein (hsCRP) levels. Serum resistin levels were positively correlated with NC (r=0.278, p=0.018). The WBC (r=0.295, p=0.012) and NC (r=0.401, p<0.001) showed a positive correlation with hsCRP levels. Regarding leptin, none of the haematological indices appeared to correlate with leptin levels.
Conclusions: Higher WBC and NC at admission predict a worse functional outcome of patients with acute ischemic stroke at hospital discharge and one year after hospitalization, due to more severe stroke with greater systemic inflammation. In addition, lower LC and higher NLR and PLR at admission seem to be associated with adverse outcome at 1 year after discharge due to a higher degree of systemic inflammation and greater disability at discharge. Adipokines appear to affect peripheral blood cell counts and are associated with haematological indices. In particular, adiponectin was positively correlated with NLR and PLR, while negatively with Hb. In addition, resistin was positively correlated with NC. These associations reflect the role of haematological indices as biomarkers of inflammation and possibly their determinant effect, through adipokines and inflammation, on the pathophysiology and prognosis of acute ischemic stroke.
Keywords: acute ischemic stroke, haematological indices, adipokines, severity, in-hospital outcome, long-term outcome