Patients with schizophrenia and chronotropic incompetence (CI) do not appear to benefit as well as schizophrenia patients without CI from aerobic exercise training interventions, a new study found. Researchers attempted to replicate the occurrence of CI in an independent sample of patients with schizophrenia and evaluate whether CI can be influenced by a continuous endurance training of 12 weeks. They found:
- Fitness testing data of 43 patients with schizophrenia and 22 age- and gender-matched controls were re-analyzed.
- Patients with schizophrenia were less physically fit than healthy controls and displayed a significantly higher heart rate at rest.
- 10 of 43 patients with schizophrenia and no healthy controls were classified as chronotropically incompetent.
- Chronotropic response to exercise did not change significantly after 12 weeks of continuous aerobic exercise training.
- Aerobic fitness did not improve significantly in patients with schizophrenia classified as chronotropically incompetent.
Herbsleb M, Keller-Varady K, Wobrock T, et al. The influence of continuous exercising on chronotropic incompetence in multi-episode schizophrenia. [Published online ahead of print March 13, 2019]. Front Psychiatry. doi:10.3389/fpsyt.2019.00090.
Chronotropic incompetence (CI) is the inability of the heart to increase pulse rate in response to increased physical activity or higher metabolic demand and is a known risk factor for cardiovascular events like heart attack as well as early mortality. Reduced CI in patients with schizophrenia might help explain a lesser degree of physical fitness and failure to benefit from exercise. This re-analysis of fitness testing in 43 patients with schizophrenia found approximately 1 in 4 with CI, which did not appear to improve even with 12 weeks of continuous aerobic exercise training. The clinical implications of the findings are quite sobering, and standard recommendations on target levels of physical activity may fail to yield observable benefit in spite of patient’s dedicated efforts. At the very least, clinicians should strive to “do no harm” while prescribing schizophrenia drug treatments that might help minimize cardiovascular risk. —Martha Sajatovic, MD, Professor of Psychiatry and of Neurology; Willard Brown Chair in Neurological Outcomes Research; Director, Neurological and Behavioral Outcomes Center, University Hospitals Cleveland Medical Center; Case Western Reserve University School of Medicine.