Dynamic Microvascular Blood Flow Analysis During Post-Occlusive Reactive Hyperemia Test in Patients with Schizophrenia

Abstract

Patients suffering from schizophrenia have an increased mortality risk due to cardiovascular events. Recently the analysis of peripheral circulation has revealed interesting results in the study of vascular pathological conditions assuming that the state of microcirculation of the skin is at least partly representative for the constitution of other vascular beds including those of the cardiac muscle and arteries. The objective of this study was to investigate the microcirculation in patients with acute schizophrenia (PAT, n = 15, mean age 33.0 years, 7 male, 8 female) to identify whether spectral features from blood flow signals derived through laser Doppler spectrometry are significantly altered compared to healthy subjects (CON, n = 15, mean age 32.4 years, 7 male, 8 female) by means of the post-occlusive reactive hyperemia test. It was also explored if a segmentation of the post-ischemic stage can disclose more detailed and additional information about the dynamic behavior of the blood flow during hyperemic response. For this reason, time-frequency analyses were performed to observe the course of the blood flow frequency components over time. Our results indicate significant differences in the patients group, already detectable under baseline conditions but also in the hyperemic phase. The main modifications affect the respiratory (p = 0.006) as well as the cardiac (p = 0.001) activity. It was further shown that the application of a segmented analysis of the post-ischemic state considerably improves the differentiation between both groups. Only with the introduced segmentation algorithm using a window length of 2048 samples and a shift of 128 and 256 samples we could demonstrate influences of the disease on the endothelial (p = 0.029), the sympathetic (p = 0.019) and the myogenic (p = 0.029) mechanisms. These information provide further insights into the appearance of schizophrenia and could lead to an improvement of the patients' treatment to avoid the occurrence of cardiovascular events.

Microvascular dysfunction in schizophrenia: a case–control study

“…Our study provides a comprehensive assessment of macro- and microvascular endothelial functions via VTI, PAT, and FMD in subjects with schizophrenia and matched healthy controls to the age of 45. Our findings are consistent with other studies that have found a attenuation of microvascular endothelial function; however, these studies used Laser-Doppler flowmetry, which measures blood flow in the superficial dermal plexus 50 , 51 or applied retinal vasculature assessment. 52 Although both groups were matched for age, sex, and smoking status, we still observed differences in other demographic and clinical parameters.…”

Coronary Artery Disease in Patients with Severe Mental Illness

“…11 Patients with schizophrenia have impaired endothelial and microvascular peripheral blood flow response, while patients with BD have elevated levels of biomarkers associated with endothelial function. [12][13][14][15][16][17] There is also strong evidence for increased oxidative stress in SMI. A meta-analysis of 44 studies found increased markers of oxidative stress in patients with BD, seen in unmedicated patients, but not in those receiving effective antipsychotic therapy.…”

Correlation between autonomic dysfunction and impaired microcirculation in patients with schizophrenia

“…Bär et al [3,4] found a significant reduction of baroreflex sensitivity and heart rate variability as well as an increase of QT variability in schizophrenic patients indicating an autonomic imbalance. Recently the analysis of peripheral microcirculation by means of Laser Doppler Flowmetry (LDF) has revealed a significantly altered microcirculation in patients with acute schizophrenia compared to healthy subjects [5]. The LDF is a non-invasive technology that facilitates the study of microcirculation via spectral analysis of the LDF signal.…”