Promotion of cardiorespiratory fitness in schizophrenia: a clinical overview and meta-analysis

Abstract

Objective: Cardiorespiratory fitness (CRF) is a major modifiable risk factor for cardiovascular disease (CVD). We conducted a clinical overview to highlight the reduced CRF expressed as maximal oxygen uptake (VO2max) (or predicted) or peak oxygen uptake (VO2 peak) in people with schizophrenia compared to the general population. We also aimed to identify correlates of and clinical strategies to improve CRF.

Method: We systematically searched major electronic databases from inception until November 2014. A meta-analysis calculating the standardised mean difference (SMD) was employed.

Results: CRF was significantly reduced in people with schizophrenia (n = 154) with a SMD of -0.96 (95% CI -1.29 to -0.64) (N = 5) compared to controls (n = 182). Negative symptoms, increased body mass index and female gender were negatively associated with CRF. Promoting physical activity may improve CRF in people with schizophrenia by up to 4-4.5 ml/kg/min following a 6-8 weeks programme (N = 4, n = 98).

Conclusion: People with schizophrenia have a large and significantly reduced CRF. Given the overwhelming evidence for physical activity as the cornerstone of preventing and managing CVD in the general population, incorporating such interventions in the treatment of people with schizophrenia is justified and urgently required. We present clear practical strategies of how this can be achieved within clinical settings.

Keywords: exercise; physical activity; physical fitness; psychosis; schizophrenia.