Objective: To investigate responsiveness of the autonomic nervous system in rheumatoid arthritis (RA) of recent onset.
Methods: 21 patients (17 women, mean age 55.7 years) and 20 healthy controls (16 women, mean age 52.7 years) were subjected to 4 tasks eliciting divergent autonomic reactions: film watching, mild physical exercise, cognitive discrimination, and the Stroop color-word interference test. Changes in heart rate, diastolic (DBP) and systolic (SBP) blood pressure, and skin conductance relative to pretask baseline values were computed and related to erythrocyte sedimentation rate, pain, mobility, and dexterity.
Results: Mean autonomic levels of patients were normal, as well as autonomic responses to film watching and mild physical exercise. Diminished autonomic responses were observed during cognitive discrimination and during the Stroop test. Blood pressure responses were negatively related to pain severity, but positively to impaired dexterity.
Conclusion: Diminished autonomic nervous system response is observed in RA of recent onset, most clearly in patients with more severe pain. This suggests that it is associated with primary pathophysiological mechanisms.