Disturbances of autonomic nervous function in primary Sjögren's syndrome.

Autonomic nervous function was evaluated by deep breathing [expiration/inspiration (E/I) ratio] and tilt table tests [acceleration (AI) and brake indices (BI)] in 19 patients with primary Sjögren's syndrome (pSS) and in 56 age matched controls. The E/I-ratio and systolic blood pressure (at rest, 1, and 8 min after tilt) were found to be significantly reduced (p < 0.001, p < 0.05, p < 0.01, p < 0.01 respectively) in patients with pSS whereas neither AI, BI nor diastolic blood pressure did differ significantly between patients and controls (NS). The van Bijsterveld's score correlated negatively with the AI (r = -0.77, p < 0.001) as well as the BI (r = -0.60, p < 0.01). No correlations were found between the 3 autonomic nerve function parameters (E/I-ratio, AI, BI) and unstimulated whole sialometry or salivary gland scintigraphy. We conclude that autonomic disturbances, mainly affecting the parasympathetic nerves are associated with pSS.