R House1, D Jiang, A Thompson, T Eger, K Krajnak, J Sauvé, M Schweigert. 1. Division of Occupational and Environmental Health, Dalla Lana School of Public Health, University of Toronto, 155 College Street, Toronto, Ontario M5T 3M7, Canada. houser@smh.toronto.on.ca
Abstract
BACKGROUND: Previous studies have suggested that the presence of the vascular component of hand-arm vibration syndrome (HAVS) in the hands increases the risk of cold-induced vasospasm in the feet. AIMS: To determine if objectively measured cold-induced vasospasm in the hands is a risk factor for objectively measured cold-induced vasospasm in the feet in workers being assessed for HAVS. METHODS: The subjects were 191 male construction workers who had a standardized assessment for HAVS including cold provocation digital photocell plethysmography of the hands and feet to measure cold-induced vasospasm. Bivariate analysis and multinomial logistic regression were used to examine the association between plethysmographic findings in the feet and predictor variables including years worked in construction, occupation, current smoking, cold intolerance in the feet, the Stockholm vascular stage and plethysmographic findings in the hands. RESULTS: Sixty-one (32%) subjects had non-severe vasospasm and 59 (31%) had severe vasospasm in the right foot with the corresponding values being 57(30%) and 62 (32%) in the left foot. Multinomial logistic regression indicated that the only statistically significant predictor of severe vasospasm in the feet was the presence of severe vasospasm in the hands (OR: 4.11, 95% CI: 1.60-10.6, P < 0.01 on the right side and OR: 4.97, 95% CI: 1.82-13.53, P < 0.01 on the left side). Multinomial logistic regression analysis did not indicate any statistically significant predictors of non-severe vasospasm in the feet. CONCLUSIONS: Workers assessed for HAVS frequently have cold-induced vasospasm of their feet. The main predictor of severe vasospastic foot abnormalities is severe cold-induced vasospasm in the hands.
BACKGROUND: Previous studies have suggested that the presence of the vascular component of hand-arm vibration syndrome (HAVS) in the hands increases the risk of cold-induced vasospasm in the feet. AIMS: To determine if objectively measured cold-induced vasospasm in the hands is a risk factor for objectively measured cold-induced vasospasm in the feet in workers being assessed for HAVS. METHODS: The subjects were 191 male construction workers who had a standardized assessment for HAVS including cold provocation digital photocell plethysmography of the hands and feet to measure cold-induced vasospasm. Bivariate analysis and multinomial logistic regression were used to examine the association between plethysmographic findings in the feet and predictor variables including years worked in construction, occupation, current smoking, cold intolerance in the feet, the Stockholm vascular stage and plethysmographic findings in the hands. RESULTS: Sixty-one (32%) subjects had non-severe vasospasm and 59 (31%) had severe vasospasm in the right foot with the corresponding values being 57(30%) and 62 (32%) in the left foot. Multinomial logistic regression indicated that the only statistically significant predictor of severe vasospasm in the feet was the presence of severe vasospasm in the hands (OR: 4.11, 95% CI: 1.60-10.6, P < 0.01 on the right side and OR: 4.97, 95% CI: 1.82-13.53, P < 0.01 on the left side). Multinomial logistic regression analysis did not indicate any statistically significant predictors of non-severe vasospasm in the feet. CONCLUSIONS: Workers assessed for HAVS frequently have cold-induced vasospasm of their feet. The main predictor of severe vasospastic foot abnormalities is severe cold-induced vasospasm in the hands.