The study shows that patients with schizophrenia have a higher rate of cardiovascular autonomic neuropathy

Testing for cardiovascular autonomic neuropathy (CAN), which manifests itself in patients with schizophrenia, may help detect early stages of cardiovascular disease (CVD) in these patients, according to a study published in the Nordic Journal of Psychiatry.

The researchers conducted a cross-sectional study from December 2015 to May 2017 at the Department of Cardiology at Aalborg University Hospital in Denmark in collaboration with Aalborg Psychiatry University Hospital.

Researchers included 46 adult patients with schizophrenia for more than 10 years from an ongoing observational study they had age-matched (within 5 years) and gender-matched controls with no psychiatric illness or diabetes.

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Researchers performed CAN assessments using the VagusTM handheld device, which records single lead electrocardiogram (EKG) traces that calculate heart rate variability (HRV). They asked participants to stop smoking, eating, and drinking caffeinated liquids at least 2 hours before recording the EKG in 3 cardiac reflex tests (CARTs). The tests they performed were responding to standing (RS) after standing still for 5 minutes, exhaling on inspiration (EI) after resting for 5 minutes and taking 6 deep breaths, and the Valsalva maneuver (VM), where exhaling forcibly was placed in a manometer at a pressure of 40 mmHG for 15 seconds.

HRV was defined as the ratio of the longest interval to the shortest interval between heartbeats and adjusted for age. The researchers obtained CAN scores (no, early, and manifest) by evaluating the results of CARTS.

In a comparison of the baseline data for each group, far more patients with schizophrenia were active smokers (87%) than the members of the control group (29%). Compared to the control group (11% and 0%), more patients with schizophrenia were obese (38%) and were being treated for diabetes (17%) (P = 0.005 and P = 0.003, respectively).

Patients with schizophrenia had a significantly higher manifested CAN (39%) and early CAN (22%) than the group of healthy controls (6% and 9%, respectively, P <0.0001 for both sets of results).

In the sensitivity analysis, the researchers compared patients with schizophrenia who were not diagnosed with diabetes with the healthy controls and found similar results (37% versus 5% for controls, P <0.0001).

The limitations of the study included that the number of incomplete CARTs was higher in the schizophrenia group and that the control sample was not really generalizable.

“CAN is common in patients with schizophrenia regardless of diabetes status,” the researchers wrote. “Testing for CAN is feasible and could be a new clinical tool for detecting early stages of CVD in patients with schizophrenia.”

Disclosure: A researcher is a co-inventor of the medical device VagusTM and has declared that it is part of Medicus Engineering. Two other researchers declared that they belonged to the pharmaceutical industry. For a full list of the authors’ information, see the original reference.


Omar M., Wieben ES, Polcwiartek C. et al. Cardiovascular autonomic neuropathy in patients with schizophrenia. Nordic J of Psychiatry. Published online on April 7, 2021. doi: 10.1080 / 08039488.2021.1902566

This article originally appeared on Psychiatry Advisor

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