Long hours culture increases heart attack risk for older workers

Jul 11 2002 by Brian Amble Print This Article

The UK’s long hours culture is increasing the risk of heart attacks in the some of the country’s most experienced workers, a leading medical journal announced today.

In a two year study, research in the journal Occupational and Environmental Medicine, has revealed that working over 60 hours a week and missing out on sleep can as much as double the chances of a heart attack for the 40+ age group.

Focusing on 260 men between 40-79, longer working hours were associated with fewer days off and shorter sleep – five hours or less – and those working 60+ hours a week had double, and in some situations triple, the risk of heart attack as men working 40 or fewer hours.

The Fukuoka Heart Study Group in Japan had the participants – who had been admitted to hospital for a first time heart attacks - complete a questionnaire detailing working hours, days off and sleep levels in the past month as well as the past year.

Details of potential risk factors for heart attack were also recorded such as lifestyle, weight, and conditions, such as high blood pressure, high cholesterol, and diabetes. A comparison group of 445 participants of the same age with no history of heart attack was also surveyed.

Only taking five hours or less sleep for two nights in the working week was found to be enough to double or triple the risk of heart attack. Frequent lack of sleep and fewer days off in the preceding month also significantly increased the chances of having a heart attack - more so than equivalent events in the past year.

The authors – Liu and Tanaka - suggest that sleep deprivation and lack of rest in the very recent past may act as triggers, and conclude that the optimal working week is a maximum of 40 hours, as both long hours and lack of sleep on their own are enough to increase the risks of heart attack:

‘The implications for policy are that reducing working hours in a week to 40 is desirable and those working for a prolonged time should take sufficient sleep or take at least two days rest a month,’ the authors state.

Overtime and lack of sleep can increase blood pressure and heart rate while chronic stress may induce abnormalities in heart function, the authors explain, and suggest that the combination of the two could increase sympathetic nervous system activity to the point where it triggers a heart attack.