Age-related evaluation of peripheral circulation of workers with vibration exposure

This study was designed to clarify the age variation of the indices in the accelerated plethysmography (APG) for fingers and set the standard ageing curve. The indices of APG of workers with exposure to vibration were compared with those of the standard ageing curves. The subjects were 815 male workers, ranging in age from 18 to 66, without exposure to vibration and without history of hypertension, circulatory diseases or diabetes. Their indices of APG are used establishing the standard ageing curves. The workers occupationally exposed to hand-arm vibration were also the subjects to evaluate peripheral circulation of hand. The APG was measured on the index finger tip of his dominant side by an accelerated plethysmometer. The subjects were divided into age groups at intervals of 5 years. In all age groups from 18 to 64 years, each index of APG showed an approximately normal distribution in a logarithmic scale. The mode of the distribution shifted to a lower value with increasing age. The standard ageing curves were drawn by calculating 25th, 50th and 75th percentiles by a nonparametric method for each group. Each index of the standard ageing curves dropped with increasing age. The significant age effect was slightly marked below 30 years, but marked between 30 and 50 years. The indices of APG of workers with exposure to vibration were also compared with those of the standard ageing curve. The indices of -b/a and a/d of workers with exposure to vibration were deteriorated beyond physiological change. We established the standard ageing curves for APG for male men. The technique is good for the evaluation of peripheral circulation disorder of aged workers with occupational exposure to vibration.