Chronic stress may cause an imbalance of the autonomic nervous system, thereby affecting cardiovascular as well as mental health and causing stress-related disorders. Exhaustion is a common symptom in this regard, closely associated with conditions such as burnout and depression. Physical activity plays an important role in the treatment of stress-related disorders, as it may have a positive effect on the autonomic nervous system. In addition, patients with stress-related disorders often have decreased cardiorespiratory fitness. Heart rate variability (HRV) is a non-invasive marker of autonomic nervous system. Several studies reported lower HRV in stress-related disorders compared to healthy controls and exhaustion has already been linked to reduced HRV in stress-related disorders. However, to date, research has mainly focused on comparing HRV in healthy controls and patients with stress-related disorders. Limited research exists on the relationship between exhaustion severity, physical activity and HRV, with partly conflicting results. Moreover, the effect of inpatient treatment on this relationship is largely unknown. In particular, the appropriate intensity of physical activity to ameliorate symptoms, which takes into account exhaustion severity, remains unclear.
This study aims to explore cross-sectional and longitudinal association of exhaustion severity, physical activity and HRV in the treatment of stress-related disorder.
Participants, aged 18-64 years, with an ICD-10 depressive episode (F32 or F33) and burnout syndrome (Z73), undergoing multimodal treatment in a rehabilitation clinic, specialized in the treatment of stress-related disorders, will be recruited. Exclusion criteria include (according to medical history) severe cardiovascular, metabolic and renal diseases, tricyclic medication, beta-blockers, presence of factors precluding exercise testing, BMI <17,5 / >35, known pregnancy, comorbid psychiatric disorders as well as severe drug or alcohol abuse. The Mini-International Neuropsychiatric Interview will be used to determine comorbid psychiatric disorders. The following parameters will be assessed at baseline and in the last week of treatment: Shirom-Melamed Burnout Measure to rate exhaustion severity and Beck Depression Inventory-II to measure depression severity. HRV will be assessed under laboratory (resting short-term recording), real-life (24-hour recording) and stress conditions (orthostatic test and submaximal exercise test). Cardiorespiratory fitness will be tested with the Åstrand-Rhyming test and cardiovascular health will be evaluated through blood pressure as well as pulse wave velocity. Cognitive function will be appraised with the THINC-Integrated Tool. Continues data (up to six weeks) will be collected with Garmin smart watch and includes physical activity (accelerometry), sleep, heart rate and HRV. Results will be analyzed with series of hierarchical regression models including control variables.
This study can yield crucial objective insights into exhaustion severity of individuals suffering from stress-related disorders and parameters of physical and mental functioning. Monitoring physical activity and HRV can give important feedback to patients having issues with self-awareness and stress management. Results will highlight feasibility of HRV recording methods and physical activity monitoring in a rehabilitation clinic and aim to optimize treatment of exhaustion in stress-related disorders.
Keywords: Stress-related disorders, physical activity, heart rate variability, exhaustion, rehabilitation clinic, study protocol