Effects of exercise therapy on cardiorespiratory fitness in patients with schizophrenia

Abstract

Background: Increased mortality in schizophrenia is caused largely by coronary heart disease (CHD). Low cardiorespiratory fitness (CRF) is a key factor for CHD mortality. We compared CRF in patients with schizophrenia to CRF of matched healthy controls and reference values. Also, we examined the effects of exercise therapy on CRF in patients with schizophrenia and in controls.

Methods: Sixty-three patients with schizophrenia and 55 controls, matched for gender, age, and socioeconomic status, were randomized to exercise (n = 31) or occupational therapy (n = 32) and controls to exercise (n = 27) or life as usual (n = 28). CRF was assessed with an incremental cardiopulmonary exercise test and defined as the highest relative oxygen uptake (VO(2peak)) and peak work rate (W(peak)). Minimal compliance was 50% of sessions (n = 52).

Results: Male and female patients with schizophrenia had a relative VO(2peak) of 34.3 ± 9.9 and 24.0 ± 4.5 mL.kg(-1).min(-1), respectively. Patients had higher resting HR (P < 0.01) and lower peak HR (P < 0.001), peak systolic blood pressure (P = 0.02), relative VO(2peak) (P < 0.01), W(peak) (P < 0.001), RER (P < 0.001), minute ventilation (P = 0.02), and HR recovery (P < 0.001) than controls. Relative VO(2peak) was 90.5% ± 19.7% (P < 0.01) of predicted relative VO(2peak) in male and 95.9% ± 14.9% (P = 0.18) in female patients. In patients, exercise therapy increased relative VO(2peak) compared with decreased relative VO(2peak) after occupational therapy. In controls, relative VO(2peak) increased after exercise therapy and to a lesser extent after life as usual (group, P < 0.01; randomization, P = 0.03). Exercise therapy increased W(peak) in patients and controls compared with decreased W(peak) in nonexercising patients and controls (P < 0.001).

Conclusion: Patients had lower CRF levels compared with controls and reference values. Exercise therapy increased VO(2peak) and W(peak) in patients and controls. VO(2peak) and W(peak) decreased in nonexercising patients.