Salivary endothelin and vascular disorders in vibration-exposed workers

Objectives: This study investigated the relation between salivary endothelin, vibration exposure, and vascular disorders in a group of forestry workers. Methods: Altogether 54 forestry workers and 52 controls underwent a medical examination and a cold test with measurement of the percentage of change in finger systolic blood pressure after finger cooling from 30°C to 10°C (FSBP%_10°). Salivary endothelin concentration (ET_1-21, in fmol/ml) was measured by a commercially available enzyme-linked immunosorbent assay before and after the cold challenge. The anamnestic diagnosis of vibration-induced white finger (VWF), assisted by color charts, was based on the Stockholm Workshop criteria. Results: Six forestry workers (11%) and one control (2%) reported white fingers. Before the cold challenge, the salivary ET_1-21 concentration was significantly greater in the VWF workers than in the controls (P=0.036). The cold response of digital arteries was stronger in the VWF workers than in the controls (P1-21 concentration in both the controls and the forestry workers. For the latter, the salivary ET_1-21 concentration was significantly associated with both daily and total operating time with vibrating tools. A significant inverse relation between FSBP%_10°. and the salivary ET_1-21 concentration was observed for the forestry workers with an abnormal cold response in their digital arteries. Conclusions: This study showed an association between salivary ET_1-21 concentration, daily and cumulative vibration exposure, and vascular disorders in the fingers of professional forestry workers. Since ET_1-21 can induce powerful and long-lasting constriction of human vessels, these findings suggest a possible role of this vasopeptide in the pathogenesis of VWF.