Lack of physical activity during leisure time contributes to an impaired health related quality of life in patients with schizophrenia

Abstract

Objective

The aim of the present study was to identify if lack of physical activity participation and an impaired functional exercise capacity compared with healthy controls contributed to an impaired health related quality of life (HRQL). We also evaluated whether the presence of metabolic syndrome (MetS) could explain the variability in HRQL in patients.

Method

Patients with DSM-IV schizophrenia (n = 60) and age- and gender-matched healthy controls (n = 40) completed the SF-36 quality of life scale and the Baecke Physical Activity Questionnaire and performed a 6 minute walk test (6MWT). Patients also received a fasting metabolic laboratory screening. Linear multiple regression analysis was used to assess the associations between demographical and clinical variables and HRQL outcomes.

Results

Physical and mental HRQL and the Baecke and 6MWT-scores were significantly lower in patients with schizophrenia compared with matched healthy controls. When in schizophrenia patients all individual HRQL-predictors were included in a regression model, only BMI and lack of PA during leisure time remained significant predictors for physical HRQL while for mental HRQL no significant predictor remained. The impaired functional exercise capacity and the presence of MetS did not additionally explain the variance in HRQL.

Conclusions

Physical HRQL in patients with schizophrenia is not only related to increased BMI but also to lack of leisure time physical activity. A reduced physical HRQL in patients with MetS appears to be related to their greater BMI, rather than to MetS per se. Present findings provide further support for routinely incorporating physical activity within rehabilitation programs and clinical assessments.

Introduction

With the emergence of more effective pharmacologic treatment of psychiatric symptoms in schizophrenia, increasing attention has been paid to the development of interventions targeting long-term functional and subjective outcomes, which remain poor for many patients with schizophrenia (van Os and Kapur, 2009). Health related quality of life (HRQL) is a measure of the impact of an illness and consequent treatment upon functional health status and well-being as perceived by the patient (Fontaine and Barofsky, 2001). In patients with schizophrenia symptoms (Eack and Newhill, 2007), a higher BMI (Allison et al., 2003, Strassnig et al., 2003, De Hert et al., 2006a, Faulkner et al., 2007, Kolotkin et al., 2008), waist circumference (Faulkner et al., 2007) and subjective side-effects of antipsychotic medication (Bebbington et al., 2009) need to be considered in relation to their impact on HRQL. Also a poor social network, stigma (Sibitz et al., 2010) and neuropsychological measures including verbal ability, attention, working memory and problem-solving (Kurtz and Tolman, 2011) and smoking severity (Dixon et al., 2007) are known to be related to impairments in HRQL.

Previous research in the general population demonstrated that a sedentary lifestyle and a reduced functional exercise capacity impair HRQL (Hulens et al., 2002). This might be due to several physical limitations including musculoskeletal pain in the lower limbs and a reduced cardiovascular fitness (Hulens et al., 2003). In the same way, several studies indicate that the presence of metabolic syndrome (MetS) is associated with impaired HRQL (Ford and Li, 2008, Miettola et al., 2008), albeit data are inconsistent and limited by failure to adjust for obesity (Vetter et al., 2010). It is known that in high-risk groups MetS is associated with a lower physical activity participation and reduced functional exercise capacity (Gardner et al., 2006, Vancampfort and al., in press). One of the putative mechanisms for this association might be that MetS diminishes the peripheral circulation in the lower limbs (Gardner and Montgomery, 2008). Poor peripheral circulation limits physical activity participation (Chen et al., 2001) creating a vicious circle of sedentary behavior, worsening of cardiometabolic parameters and progressive decline in function and deconditioning (Whaley et al., 1999), which on its turn might impair HRQL.

Although the majority of schizophrenia patients are known to be sedentary (Faulkner et al., 2006, Lindamer et al., 2008) and to have a reduced functional exercise capacity (Vancampfort et al., 2011) and that MetS is highly prevalent in schizophrenia (De Hert et al., 2009, Mitchell and al., submitted for publication), it is currently unknown whether these parameters also contribute to a HRQL impairment.

The primary aim of the present study therefore was to identify if lack of physical activity participation and an impaired functional exercise capacity compared with healthy controls might contribute to an impaired HRQL in patients with schizophrenia. A secondary aim was to identify if within patients with schizophrenia also the presence of MetS might also explain the variability in HRQL.