Cardiovascular autonomic reflex tests using a handheld device in the diagnosis of cardiovascular autonomic neuropathy in patients with schizophrenia.

Study objective: This study investigated whether schizophrenia and the duration of schizophrenia were associated with cardiovascular autonomic neuropathy (CAN) by using heart rate variability (HRV) as a marker. Design: Cross-sectional study. Setting: The examinations were conducted at the Centre for Psychosis Research and at the Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark. Participants: 240 patients with first-episode and chronic schizophrenia and 180 controls. Interventions: CAN was assessed by the cardiovascular reflex tests (CARTs): HR, RS ratio, E:I ratio, and VM using a handheld device. Main outcome measures: One abnormal CART was interpreted as borderline CAN and ≥2 abnormal CARTs established definitive CAN. Borderline CAN and definitive CAN together was categorized as overall CAN. Analyses were adjusted for age, sex, smoking, overweight, and hypercholesterolemia. Results: A total of 240 patients with schizophrenia (median age 42.5 [28.8, 52.3], 42.9 % women) and 180 controls (median age 45.8 [24.0, 60.1], 47.8 % women) were included, with 50.8 % of patients with schizophrenia having overall CAN compared to 27.2 % among controls. Dividing patients into patients with first-episode and chronic schizophrenia, 32.9 % vs 10 % ( Conclusion: It was demonstrated that a diagnosis of schizophrenia was associated with CAN. Patients with chronic schizophrenia had a significantly higher prevalence of CAN compared to patients with first-episode schizophrenia, suggesting an association between the duration of schizophrenia and CAN.