Autonomic arousal and heart rate variability in functional somatic disorder - a cross-sectional population-based...

Area of Science:

• Psychosomatic Medicine
• Autonomic Nervous System Function
• Clinical Psychology

Background:

• The Bodily Distress Syndrome (BDS) checklist is a validated tool for identifying functional somatic disorder (FSD).
• Previous hypotheses suggest symptom clusters in the BDS checklist reflect autonomic nervous system activity.
• Understanding the physiological underpinnings of FSD is crucial for effective diagnosis and treatment.

Purpose of the Study:

• To investigate the association between autonomic activity, measured by Heart Rate Variability (HRV), and somatic symptom profiles assessed by the BDS checklist.
• To examine HRV in relation to diagnosed Functional Somatic Disorder (FSD) based on clinical interviews.

Main Methods:

• A cross-sectional, population-based study involving 6891 participants aged 18-72 years.
• Somatic symptoms were measured using the 25-item BDS checklist.
• Heart Rate Variability (HRV) was assessed using five short-term measures (MeanRR, RMSSD, LF, HF, LF/HF) in a subsample of 1590 individuals.

Main Results:

• Higher BDS checklist scores were significantly associated with reduced HRV, particularly lower mean RR intervals.
• The strongest associations between BDS scores and HRV were observed for the cardiopulmonary symptom cluster.
• Individuals diagnosed with FSD, especially the multi-organ type, exhibited lower mean RR compared to non-cases, indicating increased sympathetic activity.

Conclusions:

• Symptom clusters measured by the BDS checklist are demonstrably linked to autonomic arousal, as indicated by HRV.
• Individuals with FSD, particularly the multi-organ subtype, show evidence of heightened sympathetic neural and neurohormonal activity.
• These findings suggest that autonomic dysregulation may represent a significant physiological mechanism underlying Functional Somatic Disorder.