Cholinergic autonomic dysfunction in veterans with Gulf War illness: confirmation in a population-based sample

Area of Science:

• Neuroscience
• Autonomic Nervous System Research
• Military Health

Background:

• Previous studies suggested cholinergic autonomic dysfunction may cause Gulf War illness symptoms.
• Symptoms include chronic diarrhea, dizziness, fatigue, and sexual dysfunction.

Purpose of the Study:

• To confirm the hypothesis of cholinergic autonomic dysfunction in Gulf War veterans.
• Utilized a larger, representative sample for a confirmatory study.

Main Methods:

• Nested case-control study design.
• Recruited representative samples of Gulf War veterans with Gulf War illness (3 variants) and a control group.
• Assessed autonomic function using the Autonomic Symptom Profile, Composite Autonomic Severity Score, and heart rate variability.

Main Results:

• Gulf War illness groups showed significantly elevated Autonomic Symptom Profile scales, particularly in orthostatic intolerance, secretomotor, gastrointestinal, sleep, urinary, and diarrhea domains.
• Composite Autonomic Severity Score was higher in all groups, with reduced sudomotor function indicating a peripheral nerve deficit.
• High-frequency heart rate variability was blunted or absent at night in all Gulf War illness groups.

Conclusions:

• Autonomic symptoms in Gulf War veterans are associated with objective cholinergic autonomic deficits.
• Findings support the hypothesis linking Gulf War illness to autonomic nervous system dysfunction.