Vibration exposure, smoking, and vascular dysfunction

Objectives-Vibration white finger (VWF), also known as "occupational Raynau d's phenomenon", is marked by arterial hyperresponsiveness and vasoconstric tion during cold stimulation. The impact of tobacco use, and by extension s topping smoking, on the long term course of the disease has been inconclusi vely characterised. The objectives of this study included assessment of the impact of tobacco use on symptoms and on objective tests in shipyard worke rs exposed to vibration, and in gauging the natural history of the disorder after stopping exposure and changing smoking patterns. Methods-In a cross sectional investigation, 601 current and former users of pneumatic tools were evaluated subjectively for cold related vascular symp toms, and tested by cold challenge plethysmography. There was follow up and subsequent testing of 199 members of the severely effected subgroup of smo kers and non-smokers, many of whom had stopped smoking in the interval betw een tests. Effects of smoking and stopping smoking on symptoms and plethsym ographic results were assessed. Results-Symptoms and measured abnormal vascular responses related to cold w ere more severe in smokers than in non smokers. Follow up of 199 severely e ffected members of the cohort, all removed from exposure for 2 years, indic ated that smokers were almost twice as likely to have more severe vasospasm (test finger/ control finger systolic blood pressure% (FSBP%) <30) than we re non-smokers (-32.2% v 17.4%). 53 Subjects who stopped smoking during the interval between tests improved, and were indistinguishable from non-smoke rs similarly exposed to vibration. Additional physiological benefits of sto pping smoking were still apparent at further follow up examination, 1 year later. Improvements evident on plethysmography were not accompanied by impr ovements in symptoms, which were unaffected by smoking. Conclusions-Smoking seems to delay physiological improvement in response to cold challenge in workers with VWF, after the end of exposure to vibration . Symptoms were less likely to improve over time than digital blood pressur e, and were less affected by smoking.