Blood viscosity and inflammation in first-episode and acute exacerbations of schizophrenia: A case-control study with healthy controls

Introduction: Elevated proinflammatory status and alterations in blood flow, both of which are associated with the pathophysiology of schizophrenia, may be linked with an increased risk of cardiovascular diseases. However, such a relationship at different acute stages of schizophrenia has not been evaluated. We aimed to examine whether blood viscosity and systemic inflammatory status varied between first-episode schizophrenia (FES) and acute exacerbations of schizophrenia. Methods: Fifty-two patients with FES, 69 schizophrenia patients with acute exacerbation (S-AE) and 56 healthy controls (HC) were included in the study. Whole blood viscosity (WBV) was calculated according to de Simone’s formula at low and high shear rates (LSR and HSR). Systemic immune-inflammation index (SII) and systemic inflammatory response index (SIRI) were calculated from hemogram screening data at admission. Results: When adjusted for age, WBV at both LSR and HSR were significantly decreased in both FES and S-AE groups compared to HCs. Systemic inflammatory response index was significantly higher in FES patients than in the S-AE and HC groups. Total cholesterol (TC) and WBV at HSR were correlated in patients. Total cholesterol predicted WBV at LSR in patients with FES whereas other independent variables including age and SIRI did not. Conclusion: Both first and subsequent episodes of schizophrenia are associated with reduced blood viscosity. Increased inflammatory status may not fully explain such a relationship. Extrapolation of hemorheological characteristics in schizophrenia may help to stratify cardiovascular risk and reflect the pathophysiological process in the early and later stages of schizophrenia.