Stress Response Pattern of Heart Rate Variability in Patients with Functional Somatic Syndromes

Area of Science:

• Psychosomatic Medicine
• Autonomic Nervous System Physiology
• Stress-Related Disorders

Background:

• Functional somatic syndromes (FSSs) are clinically significant, often stress-related disorders.
• Autonomic dysfunction, including reduced heart rate variability (HRV), is implicated in FSSs.
• The specific autonomic response and recovery patterns to mental stress in FSSs are not well understood.

Purpose of the Study:

• To investigate and clarify the autonomic stress response and recovery patterns in patients with FSS compared to healthy controls.
• To analyze heart rate variability (HRV) during mental arithmetic stress.
• To provide insights into the pathophysiology of FSSs.

Main Methods:

• Cross-sectional study involving 79 FSS patients and 39 healthy controls.
• Measurement of HRV (inter-beat interval, low frequency power, high frequency power) during baseline, stress (mental arithmetic), and recovery periods.
• Utilized mood questionnaires and epidemiological data collection.

Main Results:

• FSS patients reported higher mood disturbance, longer illness duration, and reduced daily functioning compared to controls.
• Healthy controls exhibited a significant decrease in vagal HRV during stress and demonstrated recovery.
• FSS patients displayed a blunted ('flat') vagal stress response, with consistently low HRV throughout all phases.

Conclusions:

• Patients with FSS demonstrate an altered autonomic stress response pattern characterized by a lack of typical HRV changes.
• This altered stress response in FSS may be linked to disease severity and offers potential diagnostic and therapeutic targets.
• Findings highlight the intricate relationship between stress, autonomic function, and functional somatic syndromes.