Reduced peak oxygen uptake and implications for cardiovascular health and quality of life in patients with schizophrenia

Strength training integrated in long term collaborative care of patients with schizophrenia

INTRODUCTION

Skeletal muscle strength is reduced in patients with schizophrenia, contributing to their impaired physical health, functional performance, and potentially mental health challenges. Although short-term training programs have shown promising results, improving muscle strength and functional performance, it is unknown how exercise can be successfully integrated into the long-term clinical care of outpatients with schizophrenia.

OBJECTIVE

To investigate effects of strength training with adherence support in a collaborative care model.

METHODS

We randomized 28 men and 20 women (mean ± SD, 35 ± 11 years) to leg press maximal strength training (MST) with 4 sets at 90 % of one repetition maximum (1RM) 2 × week, facilitated by municipal service and professional supervision (TG), or a control group (CG).

RESULTS

The TG increased scaled leg press 1RM (0-3 months: 19 %; 0-6 months: 31 %, 0-12 months: 40 %, all p < .001, and 3-12 months: 18 %, p < .05) and power (0-3 months, 11 %; 0-6 months: 22 %, 0-12 months: 26 %, all p < .001, and 3-12 months: 13 %, p < .05) throughout the 1-year period compared to the CG. The increased muscle strength was accompanied by improved sit-to-stand performance (20 %) after 12 months (p < .001). Both groups also exhibited within-group improvements in walking work efficiency after 6 months (TG: 13 %; CG: 23 %) and 1 year (TG: 11 %; CG: 21 %, p < .01-0.05), but with no evident differences between the groups. Stair climbing performance remained unchanged.

CONCLUSION

Our results reveal that strength training can successfully be integrated as a part of long-term clinical care of outpatients with schizophrenia, contributing to improved functional performance.

Effect of aerobic exercise intensity on health-related quality of life in severe obesity: a randomized controlled trial

Background

Aerobic exercise is an important part of obesity treatment and may improve health-related quality of life (HRQOL). The objective of this study was to compare the effect of two different exercise programs on health-related quality of life in patients with severe obesity.

Methods

This was a single-center, open-label, randomized, parallel-group study comparing the effects of a 24-week moderate-intensity continuous training (MICT) program and a combined high-intensity interval training program with MICT (HIIT/MICT). The primary objective (specified secondary outcome) was to assess HRQOL by using the general health dimension of the Short Form Health Survey (SF-36). The secondary objectives were to assess other dimensional SF-36 scores, the impact of weight on the physical and psychosocial aspects of quality of life (IWQOL-Lite), and the burden of obesity-specific weight symptoms (WRSM).

Results

73 patients were enrolled and reported patient reported outcome measures, with 71 patients (55% females) allocated to either MICT (n = 34) or HIIT/MICT (n = 37). In the intention-to-treat analysis, general health scores increased between baseline and 24-week follow-up in both the HIIT/MICT group and the MICT group, with a mean change of 13 (95% CI 6–21) points and 11 (95% CI 5–17) points, respectively, with no difference between the groups. The effect sizes of these changes were moderate. The vitality and social functioning scores of SF-36, and the physical function and self-esteem scores of IWQOL-Lite increased moderately in both groups, with no difference between groups. The tiredness, back pain, and physical stamina scores based on WRSM showed moderate to strong changes in both the groups.

Conclusions

Patients who had completed a combined HIIT/MICT program did not experience larger improvements in general health compared with those completing a clean 24-week MICT program. Exercise may confer general health benefits independent of intensity.

Trials registration

Regional Committees for Medical and Health Research Ethics south east, Norway, October 23, 2013 (identifier: 2013/1849) and ClinicalTrials.gov December 8, 2014 (identifier: NCT02311738).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12955-022-01940-y.

Test-Retest Reliability of the Patient Activation Measure-13 in Adults with Substance Use Disorders and Schizophrenia Spectrum Disorders

Patient Activation Measure-13 (PAM-13) is a valid and widely used questionnaire that assess an individual's knowledge, confidence, and skills for self-management of their chronic illness. Although there is some evidence regarding its reliability, the test-retest reliability has not been investigated among patients with substance use disorders (SUDs) or schizophrenia spectrum disorders. We investigated the internal consistency and test-retest reliability of PAM-13 in these populations. Test-retest reliability was analysed using data from 29 patients with SUDs and 28 with schizophrenia spectrum disorders. Cronbach's α and Intraclass Correlation Coefficient (ICC) scores were used to examine internal consistency and test-retest reliability, respectively. Of the 60 collected test-retest questionnaires, 57 were included in the analyses. No mean differences between time one (T1) and time two (T2) were observed in either patient group, except for item 12 in schizophrenia spectrum disorders patients (p < 0.05). Internal consistency for T1 and T2 was 0.75 and 0.84 in SUDs patients and 0.87 and 0.81 in schizophrenia spectrum disorders patients, respectively. The ICC was r = 0.86 in patients with SUDs and r = 0.93 in patients with schizophrenia spectrum disorders. To conclude, PAM-13 showed good internal consistency and test-retest reliability in SUDs and schizophrenia spectrum disorders patients.

Is there an association between cardiorespiratory fitness and stage of illness in psychotic disorders? A systematic review and meta-analysis

BACKGROUND

Clinical staging models describe where an individual exists on a continuum from asymptomatic at-risk states (Stage 0) through to established late-stage disease (Stage 4). We applied this framework to systematically assess evidence for any associations between objectively assessed cardiorespiratory fitness (CRF) and stage of psychosis.

METHOD

Nine electronic databases were searched for relevant publications from inception until October 31, 2019. Pooled effect sizes (Hedges' g and 95% confidence intervals (95% CI)) were estimated for differences in CRF for studies that reported mean oxygen uptake (max, peak, or predicted VO₂ in ml/kg/min).

RESULTS

Thirty-eight studies were eligible. Findings indicated that suboptimal CRF can be present at Stages 0 and 1. Meta-analyses of 22 studies demonstrated that CRF was significantly reduced in individuals classified between Stages 1 and 4 compared with matched or general population controls (g = -0.93; 95% CI -1.14, -0.71). Mean VO₂ was decreased by 28% in Stage 4 compared with Stage 1 (34.1 vs. 24.66 ml/kg/min); the largest effect size for CRF reduction was reported between Stages 2 and 3 (g = -1.16; 95% CI -1.31, -1.03).

CONCLUSIONS

Although not identifying direct causal links between clinical stage and CRF, using this framework may enhance understanding of co-associations between mental and physical health markers across the entire spectrum of psychosis. Limitations include lack of research on CRF in Stages 0 and 1 alongside problems determining stage in some studies. However, impaired CRF is reported in emerging psychosis, supporting calls that early intervention programmes should address both mental and physical wellbeing.

Aerobic interval training in standard treatment of out-patients with schizophrenia: a randomized controlled trial

OBJECTIVE

To evaluate the feasibility and effects of integrating aerobic interval training (AIT) in standard care of out-patients with schizophrenia on aerobic capacity and conventional cardiovascular disease (CVD) risk factors.

METHODS

Out-patients with schizophrenia spectrum disorder were randomized to the following: 1) a training group (TG), performing AIT 2 day/week at the clinic with adherence support from municipal services; or 2) a control group (CG), given two AIT sessions and encouraged to exercise on their own. Feasibility was assessed through retention/adherence. V˙O2peak was measured directly along with conventional CVD risk factors before and after 12 weeks.

RESULTS

Of 48 out-patients, 16/25 and 18/23 completed the TG and CG respectively. After 12 weeks, V˙O2peak was higher (2.7 ± 4.8 ml/kg/min, P < 0.01) in the TG compared with the CG. The TG improved V˙O2peak by 3.1 ± 3.7 ml/kg/min (P < 0.01), while no change in the CG was observed. No intergroup difference in weight, body mass index (BMI), waist circumference, blood pressure, lipids, or glucose at posttest was observed. Weight (1.9 ± 4.0 kg, P < 0.05) and BMI (0.5 ± 1.1 kg/m² , P < 0.05) increased in the CG, with no change in the TG.

CONCLUSION

AIT, combined with adherence support, of out-patients with schizophrenia was feasible, improved V˙O2peak , and may be integrated in standard care. (ClinicalTrials.gov identifier: NCT02743143).

Cardio-respiratory fitness is associated with a verbal factor across cognitive domains in schizophrenia

OBJECTIVE

We investigated whether the relationship between cardio-respiratory fitness (CRF) and cognition in schizophrenia is general, or due to selective relationships between CRF and specific aspects of cognitive function.

METHOD

Eighty outpatients with schizophrenia spectrum disorders participated. Neurocognition was assessed with the Wechsler Adult Intelligence Scale version 4 General Ability Index (WAIS GAI), the MATRICS Consensus Cognitive Battery (MCCB) and the Emotion in Biological Motion (EBM) test. CRF was assessed with peak oxygen uptake measured directly during maximum exercise using a modified Balke protocol. Partial correlations, controlling for sex and age, were obtained for the perceptual and the verbal indices of WAIS GAI, six cognitive domains of MCCB, and the EBM total score. A factor analysis was conducted on all 15 subtests of the WAIS GAI and the MCCB, and the factors were subjected to separate regression analyses with CRF as predictor.

RESULTS

Significant, moderately sized correlations were found between CRF and all cognitive domains except processing speed. The correlation appeared strongest for CRF and the Verbal Comprehension Index of WAIS GAI (r = 0.29, p = .005). The factor analysis identified three factors: one speed/attention/executive function factor, one verbal factor, and one perceptual factor. Regression analyses showed that VO_2peak explained a significant amount of variance in the verbal factor only (R² = 0.06, β = 0.329, p = .03).

CONCLUSION

The results indicate that the relationship between CRF and cognition in schizophrenia is selectively tied to a modality-specific association with verbal cognitive abilities. These findings have implications for understanding the relation between cognitive factors and physical health in schizophrenia. ClinicalTrials.gov reg. number NCT02205684 (clinicaltrials.gov/ct2/show/NCT02205684).

The Association Between Cardiorespiratory Fitness and Cognition Appears Neither Related to Current Physical Activity Nor Mediated by Brain-Derived Neurotrophic Factor in a Sample of Outpatients With Schizophrenia

Objective: We investigated whether levels of current physical activity (PA) contribute to the established relationship between cardiorespiratory fitness (CRF) and cognition in schizophrenia and whether brain-derived neurotrophic factor (BDNF) or its precursor proBDNF mediates this relationship. Method: Sixty-one outpatients with schizophrenia spectrum disorders participated. Neurocognition was assessed with the Wechsler Adult Intelligence Scale (WAIS) and nine subtests from the MATRICS battery comprising a neurocognitive composite score (NCS). CRF was assessed with peak oxygen uptake (VO_2peak) measured directly during a maximum exercise test. Current PA levels were objectively assessed by an accelerometer worn for four consecutive days. BDNF and proBDNF were measured in fasting blood. Four serial parallel mediation analyses and two additional parallel mediation analyses were conducted, while controlling for age and sex at all levels. Results: No direct effects were found between PA measures and WAIS or NCS. No significant mediating effects of CRF or BDNF/proBDNF were detected. Conclusion: The results do not support the hypothesis that PA contributes to the naturally occurring relationship between CRF and cognition in schizophrenia or the hypothesis that BDNF or proBDNF mediates this relationship. The results arguably support the assumption that the association between CRF and cognition in schizophrenia is established developmentally early. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02205684.

The association between cardio-respiratory fitness and cognition in schizophrenia

OBJECTIVE

Schizophrenia is associated with reduced cardio-respiratory fitness (CRF), and impaired cognition is a core feature of the disorder. Despite their particular significance to schizophrenia disparately, the relationship between these two variables has not yet been thoroughly assessed. In this study we aimed to investigate naturally occurring associations between CRF and all cognitive domains within this patient population.

METHOD

Eighty outpatients with schizophrenia spectrum disorders participated in the study. Neurocognition was assessed with the Wechsler Adult Intelligence Scale version 4 General Ability Index (WAIS GAI) and the MATRICS Consensus Cognitive Battery (MCCB). Oxygen uptake was measured directly by analyzing O₂ and CO₂ content in expired air during a maximum exercise session on a treadmill using a modified Balke protocol. Clinical symptom load was assessed with the Positive and Negative Syndrome Scale (PANSS). Hierarchical multiple regression analyses were conducted, controlling for sex and age, and negative psychotic symptom levels.

RESULTS

CRF explained a significant 8.2% and 9.1% of the variance in general intellectual ability and state-sensitive cognitive functioning respectively, beyond the impact of negative psychotic symptom load.

CONCLUSION

The study indicates a direct relation between CRF and cognition in schizophrenia. Impaired cognition is a difficult-to-treat expression of the disorder, and identifying modifiable factors possibly mediating cognition, such as CRF, is of great clinical value.

Cardiorespiratory benefits of group exercise among adults with serious mental illness

This study examined cardiorespiratory fitness (CRF) among adults with serious mental illness (SMI) participating in group exercise classes. Overweight and obese adults with SMI were randomized to either a control condition or a weight management condition with group exercise classes (n = 222). Submaximal bicycle ergometry was used to assess CRF at baseline, 6 and 18 months. Those with ≥ 66% participation in the exercise classes had a lower heart rate response at 6 and 18 month follow-up. Participation in group exercise classes was associated with improved short and long term cardiovascular fitness among adults with SMI.

Effects of high-intensity aerobic exercise on psychotic symptoms and neurocognition in outpatients with schizophrenia: study protocol for a randomized controlled trial

Background

The focus in recent years on physical inactivity and metabolic disturbances in individuals with schizophrenia raises the question of potential effects of physical activity. Physical activity has shown beneficial effects on cognition in healthy older individuals as well as on symptom severity in depression. However, opinions diverge regarding whether aerobic high-intensity interval training reduces cognition and key symptoms in schizophrenia. The main objective for the trial is to investigate the potential effects of aerobic high-intensity interval training on neurocognitive function and mental symptoms in outpatients with schizophrenia.

Methods/Design

The trial is designed as a randomized controlled, observer-blinded clinical trial. Patients are randomized to 1 of 2 treatment arms with 12-week duration: aerobic high-intensity interval training or computer gaming skills training. All participants also receive treatment as usual. Primary outcome measure is neurocognitive function. Secondary outcome measures will be positive and negative symptoms, wellbeing, tobacco-smoking patterns and physiological/metabolic parameters. Patient recruitment takes place in catchment area-based outpatient clinics.

Trial registration

ClinicalTrials.gov NCT02205684. Registered 29 July 2014.

Prefrontal and Hippocampal Brain Volume Deficits: Role of Low Physical Activity on Brain Plasticity in First-Episode Schizophrenia Patients

Our objective in the present study was to conduct the first empirical study of the effects of regular physical activity habits and their relationship with brain volume and cortical thickness in patients in the early phase of schizophrenia. Relationships between larger brain volumes and higher physical activity levels have been reported in samples of healthy and aging populations, but have never been explored in first-episode schizophrenia patients.

METHOD

We collected MRI structural scans in 14 first-episode schizophrenia patients with either self-reported low or high physical activity levels. We found a reduction in total gray matter volume, prefrontal cortex (PFC), and hippocampal gray matter volumes in the low physical activity group compared to the high activity group. Cortical thickness in the dorsolateral and orbitofrontal PFC were also significantly reduced in the low physical activity group compared to the high activity group. In the combined sample, greater overall physical activity levels showed a non-significant tendency with better performance on tests of verbal memory and social cognition. Together these pilot study findings suggest that greater amounts of physical activity may have a positive influence on brain health and cognition in first-episode schizophrenia patients and support the implementation of physical exercise interventions in this patient population to improve brain plasticity and cognitive functioning.

Treatment resistance and other complicating factors in the management of schizophrenia

Treatment resistance, along with its sibling partial response, remains a common phenomenon in schizophrenia, complicating the disability burden inherent in the disease. Antipsychotic medications are the mainstay of treatment, and treatment resistance has mainly been defined in terms of poor response to antipsychotic medication. At the same time, clozapine, the most effective antipsychotic, remains underutilized at the expense of exposing patients to polypharmacy. We review known causes of disability in schizophrenia, how they impact various areas of everyday functioning, and discuss potential treatment options including but not limited to pharmacological approaches aimed at maximizing treatment response and reducing treatment resistance.

High aerobic intensity training and psychological States in patients with depression or schizophrenia

AIM

To explore changes in psychological states in response to a bout of high aerobic intensity training (HIT) in patients with depression or schizophrenia compared to healthy individuals.

METHODS

After familiarization training of HIT, 20 patients with schizophrenia, 13 patients with depression, and 20 healthy individuals performed a no-training day followed by a training day. HIT was 4 × 4 min intervals at 85-95% of peak heart rate, intermitted by 3 min active rest periods at 70% of peak heart rate. Self-evaluation questionnaires of positive affect, negative affect, state anxiety, well-being, distress, and fatigue were completed before training, 15 min after, and 3 h after training. The two latter measures were also completed the no-training day.

RESULTS

All three groups improved in positive affect and well-being 15 min after HIT (p < 0.01), but only patients with depression had maintained the effect after 3 h (p = 0.007, p = 0.012). The duration of the improved positive affect was longer in depression (p = 0.002) and schizophrenia (p = 0.025) than in healthy individuals (F 2.50 = 5.83, p < 0.01). Patients with depression or schizophrenia had reduced distress and state anxiety 15 min after HIT and 3 h after HIT (p < 0.05). The improvement in distress 15 min after HIT was larger in patients with depression (p = 0.028) compared to healthy individuals (F 2.50 = 5.05, p < 0.01). No changes were found during the no-training day (p > 0.05).

CONCLUSION

High aerobic intensity training used as an acute intervention improved positive affect and well-being and reduced distress and state anxiety in patients with depression and schizophrenia. ClinicalTrials.gov identifier: NCT01310998.

Differences in Aerobic Fitness between Inpatients and Outpatients with Severe Mental Disorders

BACKGROUND

Patients with severe mental disorders have increased mortality, and cardiovascular disease (CVD) accounts for a large part. Physical inactivity and low aerobic fitness have been recognized as significant risk factors for CVD. In this study, we investigated the differences in aerobic fitness and physical activity between in- and outpatients with severe mental disorders.

METHOD AND SUBJECTS

Fifty in- and outpatients from a regional psychiatric department were included. The patients filled in a questionnaire on physical activity and completed a clinical examination. An estimation of aerobic fitness was calculated for each patient, using gender, age, waist circumference, resting heart rate, and physical activity level as variables.

RESULTS

Inpatients had lower estimated aerobic fitness than outpatients (VO2peak 42 vs. 50 mL kg(-1) min(-1), p < 0.001). Compared to population data matched for age and gender, inpatients had lower aerobic fitness, while outpatients were not different from the population average.

CONCLUSION

Inpatients at a psychiatric department had lower estimated aerobic fitness than outpatients, and a lower aerobic fitness compared to the general population. Our findings suggest that inpatients with severe mental disorders should be considered a high risk group for CVD.

Differential cardiac effects of aerobic interval training versus moderate continuous training in a patient with schizophrenia: a case report

Increased cardiovascular morbidity and mortality rates for patients with schizophrenia are reported to contribute to their reduced life expectancy. Common reasons for increased cardiac mortality rates include cigarette smoking, obesity, dyslipidemia, diabetes, and poorer health behavior in general. The majority of excess mortality among people with schizophrenia is caused by cardiovascular complications. Reduced vagal activity might be one important mechanism leading to this increased cardiac mortality and has been consistently described in patients and their healthy first-degree relatives. In this case study, we compared two different aerobic exercise regimes in one patient with chronic schizophrenia to investigate their effects on cardiovascular regulation. The patient completed a 6-week period of moderate continuous training (CT) followed by a 6-week period of interval training (IT), each regime two times per week, on a stationary bicycle. This was followed by a 6-week period of detraining. Primary outcome measures examined heart rate (HR) and heart rate variability (HRV) at rest while secondary measures assessed fitness parameters such as the ventilatory threshold 1 (VT1). We observed that IT was far more effective than moderate CT in increasing HRV, as indicated by root mean of squared successive difference (improvement to baseline 27 versus 18%), and reducing resting HR (-14 versus 0%). Improvement in VT1 (21 versus -1%) was only observed after IT. Our study provides preliminary data that the type of intervention is highly influential for improving cardiac function in patients with schizophrenia. While cardiovascular function might be influenced by CT to some degree, no such effect was present in this patient with schizophrenia. In addition, the beneficial effect of IT on HR regulation vanished completely after a very short period of detraining after the intervention.

Exercise therapy improves mental and physical health in schizophrenia: a randomised controlled trial

OBJECTIVE

The objective of this multicenter randomised clinical trial was to examine the effect of exercise versus occupational therapy on mental and physical health in schizophrenia patients.

METHOD

Sixty-three patients with schizophrenia were randomly assigned to 2 h of structured exercise (n = 31) or occupational therapy (n = 32) weekly for 6 months. Symptoms (Positive and Negative Syndrome Scale) and cardiovascular fitness levels (Wpeak and VO2peak ), as assessed with a cardiopulmonary exercise test, were the primary outcome measures. Secondary outcome measures were the Montgomery and Åsberg Depression Rating Scale, Camberwell Assessment of Needs, body mass index, body fat percentage, and metabolic syndrome (MetS).

RESULTS

Intention-to-treat analyses showed exercise therapy had a trend-level effect on depressive symptoms (P = 0.07) and a significant effect on cardiovascular fitness, measured by Wpeak (P < 0.01), compared with occupational therapy. Per protocol analyses showed that exercise therapy reduced symptoms of schizophrenia (P = 0.001), depression (P = 0.012), need of care (P = 0.050), and increased cardiovascular fitness (P < 0.001) compared with occupational therapy. No effect for MetS (factors) was found except a trend reduction in triglycerides (P = 0.08).

CONCLUSION

Exercise therapy, when performed once to twice a week, improved mental health and cardiovascular fitness and reduced need of care in patients with schizophrenia.