Blood Pressure and Heart Rate Variability in Taxi Drivers on Long Duty Schedules

Abstract

Blood Pressure and Heart Rate Variability in Taxi Drivers on Long Duty Schedules: Fumio KObayashi, et al. Department of Health and Psychosocial Medicine, Aichi Medical University School of Medicine Objective To clarify the mechanisms of excessive risk of cardiovascular disease among taxi drivers, the effects of taxi driving with long work hours on taxi drivers' blood pressure and heart rate variability were examined. Methods We measured the physical activity level, ambulatory blood pressure, and Holter ECG in 34 healthy middleaged male taxi drivers over one work day and the two following non‐work days. The subjects worked for a 24‐h period starting at 07:00, then rested from work for 48 h. Ambulatory blood pressure was recorded automatically at 30‐min intervals over the 72‐h period. Holter ECG records were also kept for the 72 h, and temporal changes in the R‐R interval were analyzed by the complex demodulation method (COM). The amplitude of the high frequency (HF) components (central frequency 0.30 Hz), and the ratio of lowfrequency components (central frequency 0.09 Hz) to high‐frequency components (LlH) was calculated. Results Blood pressure during the work day was significantly higher than that during the non‐work days, with a stronger effect in the hypertensive subjects. There were no significant overall differences in heart rate variability between the work day and the non‐work days, but the temporal patterns of HF and UH on the work day revealed a potent effect of reversed‐phased circadian rhythm for work at night. Conclusions Long duty taxi driving raises blood pressure and may increase cardiovascular risk as a result. The conflict between the circadian rhythms of autonomic nervous activity and work activity at night may also result in increased risk.

Acute effects of cigarette smoking on the heart rate variability of taxi drivers during work

“…These data suggest that smoking at night has a more potent acute effect on the cardiac modulation of taxi drivers than during the day. Previous studies have confirmed the presence of a circadian rhythm with the prevalence of sympathetic activity during the day and a marked increase in parasympathetic activity during the night (14,(33)(34)(35). At night, smoking taxi drivers are therefore assumed to have their own circadian rhythms, which originally decrease sympathetic activities and increase parasympathetic ones, disturbed by the effects of smoking.…”

“…Nevertheless, the mechanisms underlying the increased risk of cardiovascular disease among taxi drivers have not yet been fully investigated. An increase in blood pressure caused by long hours of driving together with various work-related stressors (4,7,(11)(12)(13)(14)(15), such as dealing with passengers, searching for potential customers along streets and roads, waiting at taxi stands for customers, traffic jams, rain, and highway driving, may contribute substantially to the increased cardiovascular risk. Some neurophysiological mechanisms (11,(15)(16)(17), including dysfunction of the autonomic nervous system, hyperreactivity of the cardiovascular system, and disturbed circadian rhythms of the endocrine system, may also occasionally result in fatal arrhythmia or chronically accelerated coronary Kobayashi et al atherosclerosis.…”

Step On It! Workplace Cardiovascular Risk Assessment of New York City Yellow Taxi Drivers

“…38–41 In a study of Japanese taxi drivers, blood pressure during workdays was significantly higher than during non-work days. 42 Poor diet further increases CVD risk. A survey of Chicago drivers found only 5% met recommended levels of fruit and vegetable intake.…”

“Every disease…man can get can start in this cab”: Focus Groups to Identify South Asian Taxi Drivers’ Knowledge, Attitudes and Beliefs About Cardiovascular Disease and Its Risks

“…The growing taxi driver workforce is at risk for poor health status, including increased risk for cardiovascular disease (CVD). In a study of Japanese taxi drivers, blood pressure was significantly higher during work-days than during non-work days, especially among hypertensive drivers [2]. The prevalence of myocardial infarction (MI), multi-vessel disease, and CVD risk factors were significantly higher among drivers than among age-adjusted non-drivers [3].…”