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 degrees C to 10 degrees C (FSBP%10 degrees). Salivary endothelin concentration (ET1-21, 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 ET1-21 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 (P<0.001) and the asymptomatic forestry workers (P=0.008). After the cold test, there was a small, not significant, increase in the salivary ET1-21 concentration in both the controls and the forestry workers. For the latter, the salivary ET1-21 concentration was significantly associated with both daily and total operating time with vibrating tools. A significant inverse relation between FSBP%(10 degrees) and the salivary ET1-21 concentration was observed for the forestry workers with an abnormal cold response in their digital arteries. Conclusions This study showed an association between salivary ET1-21 concentration, daily and cumulative vibration exposure, and vascular disorders in the fingers of professional forestry workers. Since ET1-21 can induce powerful and long-lasting constriction of human vessels, these findings suggest a possible role of this vasopeptide in the pathogenesis of VWF.