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Effects of Schizophrenia and Bipolar Disorder on Exercise Capacity, Pulmonary Function, and Quality of Life

Investigation of Exercise Capacity, Pulmonary Function, Respiratory Muscle Strength, and Quality of Life in Patients Diagnosed With Schizophrenia and Bipolar Disorder

Status
Recruiting
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT07306468
Enrollment
150
Registered
2025-12-29
Start date
2025-11-01
Completion date
2026-12-01
Last updated
2025-12-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Bipolar Disorder (BD), Schizophenia Disorder

Keywords

schizophrenia, bipolar disorder, respiratory functions, quality of life, exercise capacity

Brief summary

This observational study aims to evaluate exercise capacity, pulmonary function, respiratory muscle strength, and quality of life in individuals diagnosed with schizophrenia and bipolar disorder. These psychiatric conditions are associated with sedentary lifestyles, metabolic side effects of psychotropic medications, and increased comorbidity risks, all of which may negatively impact physical fitness and respiratory health. By assessing cardiorespiratory endurance, pulmonary parameters (FVC, FEV₁), and respiratory muscle strength in this population, the study seeks to identify physiological limitations and contribute to the development of more effective rehabilitation strategies. The findings may support multidisciplinary approaches to improving physical health and overall quality of life in individuals with severe mental illness.

Detailed description

Schizophrenia is a mental disorder observed in approximately 4 out of every 1,000 individuals in the general population, with a morbidity rate of 0.72%. According to the Global Burden of Disease Study (2010), around 20,000 deaths occur annually due to schizophrenia-related causes. Bipolar disorder is recognized as a chronic and severe mental illness. Based on data from the World Health Organization's global burden of disease reports, bipolar disorder ranks among the top 20 diseases contributing to disability worldwide and holds the 6th position among mental disorders. Schizophrenia and bipolar disorder are serious and chronic psychiatric conditions affecting millions of individuals globally. The prevalence of schizophrenia is approximately 1%, while bipolar disorder has a lifetime prevalence of 2-3%. These disorders not only involve neuropsychiatric symptoms but also significantly impact physical health. In individuals with these conditions, sedentary lifestyle habits, metabolic side effects of antipsychotic and mood-stabilizing medications, and increased comorbidity risks are associated with notable reductions in exercise capacity. Moreover, physical inactivity and heightened inflammatory processes may adversely affect respiratory muscle strength and pulmonary function. Studies have shown that patients with schizophrenia exhibit significantly lower maximal oxygen consumption (VO₂max) and anaerobic threshold levels compared to healthy individuals. In bipolar disorder, depressive episodes are marked by reduced exercise capacity, while manic episodes often involve irregular and risky physical activities. Additionally, both disorders are associated with significantly lower pulmonary function parameters (FVC, FEV₁) compared to the healthy population. Respiratory muscle strength, a relatively underexplored area, is gaining importance. In schizophrenia cases dominated by negative symptoms, reduced inspiratory muscle strength combined with insufficient physical activity can severely limit patients' quality of life and independence. Similarly, in bipolar disorder, impairments in pulmonary capacity and respiratory muscle strength negatively affect quality of life. Quality of life in these individuals is closely linked not only to mental health but also to physical capacity and pulmonary function. Enhancing respiratory muscle strength and aerobic capacity may positively influence overall quality of life, social participation, and functional status. However, the existing literature remains limited and fragmented. There is a noticeable lack of studies that simultaneously evaluate exercise capacity, pulmonary function, and respiratory muscle strength in individuals with psychiatric disorders. This study aims to contribute to the literature from a multidisciplinary perspective by jointly examining exercise capacity, pulmonary function, respiratory muscle strength, and quality of life in individuals diagnosed with schizophrenia and bipolar disorder. These individuals often exhibit unhealthy lifestyle habits and a tendency toward sedentary behavior, which are considered risk factors that may adversely affect physical fitness. Components of physical fitness include cardiorespiratory endurance and muscular endurance. In light of this information, a review of the literature reveals that data on pulmonary function, respiratory muscle strength, and endurance in individuals with schizophrenia and bipolar disorder are still limited. The findings obtained from this study may guide the development of more effective rehabilitation and physical health support programs for these populations.

Interventions

OTHERPulmonary Function Test

Participants' respiratory functions will assess with pulmonary function test according to ATS/ERS criteria

OTHERRespiratory Muscle Strength Evaluation

Participants' respiratory muscle strenght will assess with maximal inspiratory pressure and maximal expiratory pressure assessment according to ATS/ERS criteria

OTHERQuality of Life Assessment

Participants' quality of life will assess with WHOQOL-Bref questionnaire

Participants' exercise capacity will assess with 6 Minute Walk Test according to ATS/ERS criteria

Sponsors

Çankırı Karatekin University
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes

Inclusion criteria

* Being volunteer for participation * Being 18 to 65 age

Exclusion criteria

* Having any respiratory, cardiac, neurologic or orthopedic disease which may affect respiratory functions or exercise capacity * Having any neuropsychiatric disease except schizophrenia or bipolar disorder

Design outcomes

Primary

MeasureTime frameDescription
Forced Vital Capacity (FVC) measured in liters1st dayFVC will be measured using spirometry on Day 1 of the intervention. The forced vital capacity (FVC) will be recorded in liters. Three assessments will be performed, and the highest value will be reported.
Maximum Expiratory Pressure (MEP) measured in cmH₂O1st dayMEP will be measured using a mouth pressure device on Day 1 of the intervention. The maximum expiratory pressure (MEP) will be recorded in cmH₂O. Three assessments will be performed, and the highest value will be reported.
Forced Expiratory Volume in 1 Second (FEV1) measured in liters1st dayFEV1 will be measured using spirometry on Day 1 of the intervention. The maximum expiratory volume in 1 second (FEV1) will be recorded in liters. Three assessments will be performed, and the highest value will be reported.
FEV1/FVC ratio measured as a percentage1st dayFEV1/FVC ratio will be calculated using spirometry on Day 1 of the intervention. The ratio of FEV1 to FVC will be expressed as a percentage. Three assessments will be performed, and the highest value will be reported.
Peak Expiratory Flow (PEF) measurement1st dayPEF will be measured using spirometry on Day 1 of the intervention. The peak expiratory flow (PEF) will be recorded in liters per minute. Three assessments will be performed, and the highest value will be reported.
Maximum Inspiratory Pressure (MIP) measurement1st dayMIP will be measured using a mouth pressure device on Day 1 of the intervention. The maximum inspiratory pressure (MIP) will be recorded in cmH₂O. Three assessments will be performed, and the highest value will be reported.

Secondary

MeasureTime frameDescription
WHOQOL-BREF total score measurement1st dayHealth-related quality of life will be assessed using the Turkish version of WHOQOL-BREF questionnaire. Participants will complete the 26-item survey at the 1st day. The total score will be calculated according to standardized scoring procedures and reported in points. Higher scores indicate better quality of life.
6-minute walk distance (6MWD) measured in meters1st dayThe 6-minute walk test will be conducted according to standardized procedures in a straight corridor. Participants will be instructed to walk as far as possible in 6 minutes with standardized encouragement. The total distance walked will be recorded in meters. If a test is interrupted, the distance completed will be recorded. Two assessments will be performed on the same day, separated by a 30-minute rest interval. The 6-minute walk distance (6MWD) will be measured in meters, and the best (highest) distance will be reported.

Countries

Turkey (Türkiye)

Contacts

Primary ContactFurkan Özdemir, PT, Ph.D.
furkanozdemir@karatekin.edu.tr+905383264855

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026