Background: Cardiovascular autonomic neuropathy (CAN) is an independent predictor of cardiovascular disease (CVD) in patients with diabetes as well as in patients with pre-diabetes and metabolic syndrome. Patients with schizophrenia have an increased rate of metabolic syndrome, pre-diabetes and diabetes as compared to the general population. Despite of this, occurrence CAN has not been investigated in patient with schizophrenia. Therefore, the aims of this study were (1) to evaluate the feasibility testing for CAN with a new clinical tool and (2) report the prevalence of early and manifest CAN in patients with schizophrenia.
Methods and results: Patients with diagnosed schizophrenia and with a disease duration ≥10 years were matched 1:1 on age and gender at screening with psychiatric healthy controls. CAN was defined as ≥ two abnormal standard cardiovascular autonomic reflex tests (lying-to-standing, deep breathing, and Valsalva maneuver) using the VagusTM device. A total of 46 patients with schizophrenia were included and matched to psychiatric healthy controls. Manifest CAN were more frequently presented in patients with schizophrenia (39% vs. 6% for controls, p<.0001). Sensitivity analysis of 41 subjects with schizophrenia without diabetes matched to 41 psychiatric healthy controls, showed similar results (37% vs. 5% for controls, p<.0001).
Conclusion: CAN is highly prevalent in patients with schizophrenia. Testing for CAN is feasible and might be a new clinically tool for detecting early stages of CVD in patients with schizophrenia.
Keywords: Cardiovascular autonomic neuropathy; cardiovascular autonomic reflex test; heart rate variability; schizophrenia.