Post-COVID-19 syndrome is associated with persistent symptoms such as fatigue, reducedphysical activity, and impaired respiratory function. Circadian rhythm differences(chronotype) may influence lifestyle behaviors including physical activity, nutrition,and sleep patterns.This observational cross-sectional study aims to compare respiratory muscle strength,physical activity levels, and nutritional habits among individuals with post-COVID-19syndrome according to their chronotype (morning, intermediate, and evening types).Additionally, genetic analysis of the CLOCK gene polymorphism will be performed tosupport objective evaluation of circadian rhythm differences. The findings of this studymay help to better understand the role of circadian rhythm in post-COVID-19 syndrome andcontribute to the development of individualized rehabilitation and lifestyleinterventions.
Post-COVID-19 syndrome is characterized by persistent symptoms such as fatigue, reduced
exercise tolerance, and impaired respiratory function following acute SARS-CoV-2
infection. Emerging evidence suggests that circadian rhythm disruption may play a role in
the pathophysiology of these symptoms by affecting metabolic regulation, hormonal
balance, sleep quality, and physical performance.
Circadian rhythm varies between individuals and is commonly classified into chronotypes
as morning, intermediate, and evening types. These chronotypes are associated with
differences in daily activity patterns, nutritional behaviors, and physiological
performance.
The aim of this observational cross-sectional study is to compare respiratory muscle
strength, physical activity levels, nutritional habits, sleep quality, fatigue
perception, and gastrointestinal symptoms in individuals with post-COVID-19 syndrome
according to their chronotype.
Participants aged 18-65 years with a confirmed diagnosis of post-COVID-19 syndrome will
be included. Chronotype will be assessed using the Munich Chronotype Questionnaire
(MCTQ). Respiratory muscle strength will be evaluated using maximal inspiratory and
expiratory pressures (MIP/MEP), and dynamic respiratory parameters will be assessed using
a POWERbreathe device. Respiratory muscle endurance will be measured using threshold
loading protocols.
Physical activity levels will be assessed using the International Physical Activity
Questionnaire (IPAQ), while nutritional intake will be evaluated using 24-hour dietary
recall. Sleep quality, fatigue severity, and gastrointestinal symptoms will be assessed
using validated questionnaires.
In addition, blood samples will be collected for genetic analysis of the CLOCK gene
polymorphism (rs1801260) using PCR-RFLP techniques to provide an objective assessment of
circadian rhythm differences.
This study is expected to provide comprehensive insight into the relationship between
circadian rhythm and functional, behavioral, and physiological outcomes in post-COVID-19
syndrome, and may contribute to the development of individualized rehabilitation
strategies.
Inclusion Criteria:
- Diagnosed with Post-COVID-19 Syndrome
- Aged between 18-65 years
- Able to read and understand Turkish
- Voluntary participation
- Classified as Post-Covid Functional Status Scale (PCFS) grade 2-3
- Clinically stable condition
- No uncontrolled comorbidities (e.g., hypertension, diabetes under control)
- No orthopedic or neurological conditions affecting exercise testing
Exclusion Criteria:
- Recent myocardial infarction or pulmonary embolism
- Severe uncontrolled chronic diseases
- Neurological or orthopedic conditions limiting mobility
- Psychiatric or neurological disorders affecting cooperation or test compliance
- Inability to complete assessments
Hacettepe University Faculty of Physical Therapy and Rehabilitation
Ankara, Altindağ, Turkey (Türkiye)
Investigator: EBRU ÇALIK, Professor
Contact: +905442850087
ecalik85@gmail.com
Ebru Çalık, Professor
+905442850087
ecalik85@gmail.com
Not Provided