To investigate autonomic nervous system function in patients with primary Sjögren's syndrome (SS) and relate the findings to clinical variables.
Autonomic nervous system function was determined in 30 patients with primary SS using the finger skin blood flow test [vasoconstrictory (VAC) index], deep-breathing test [expiration/inspiration (E/I) ratio], and the tilt table (orthostatic) test [acceleration index (AI), brake index (BI), and orthostatic blood pressure]. The results were compared with age matched control materials (finger skin blood flow test, n = 80, and deep-breathing and tilt table tests, n = 56).
The VAC index was found to be significantly increased and the E/I ratio significantly decreased in patients compared to controls, indicating both a sympathetic and a parasympathetic dysfunction. Further, the patients, especially the anti-SSA and anti-SSB antibody seropositives, were found to have an abnormal blood pressure reaction to tilt compared to controls. No correlations were found between autonomic nerve function variables measured and the clinical ophthalmologic or the oral tests, performed at the time of diagnosis.
Patients with primary SS show signs of both sympathetic and parasympathetic dysfunction. Further, immunological mechanisms seem to influence blood pressure in patients with primary SS.