718 Tremor measurements in a twenty-two year longitudinal study of workers exposed to hand-held vibrating tools

Background Use of hand-held vibrating tools may lead to hand-arm vibration syndrome (HAVS), which is composed of vascular, neurological and muscular components. Few studies have investigated possible long-term effects on tremor related to hand-held vibrating tools. Objectives The objectives were to evaluate postural and rest hand tremor in workers with current and previous exposure to vibrating hand tools, taking into account the possible effects from medical conditions and life-style habits such as tobacco and alcohol consumption. Subjects and methods Forty workers previously employed in a specialised engineering and construction company were examined with a test-battery and a clinical examination in 1994 and 2017. Age at last examination was 60.7 years (44.6 to 77.8 years). Hand tremor was measured in 2016/2017 with the Tremor Pen from CATSYS. Their exposure to hand-held vibrating tools was assessed as acceleration x lifetime exposure. Biological samples of Carbohydrate-deficient transferrin (CDT), glycated haemoglobin (HbA1c), cotinine, nicotine and caffeine were collected on the day of examination. Results The data collection was finished by ultimo March 2017. Preliminary results indicate that tobacco consumption assessed by cotinine in serum and diabetes assessed by HbA1c were more closely associated with tremor parameters than lifetime exposure to hand-held vibrating tools. For all subjects the magnitude of the tremor, the tremor Intensity, was 0.15 and 0.13 ms -2 for the dominant and non-dominant hands respectively. The hand position is important when testing for tremor. When postural and rest tremor measures were compared, the frequency of the tremor increased significantly, from 7.4 to 9.8 Hz and from 7.6 to 9.3 Hz for the dominant and non-dominant hands respectively.