Heart risk from working overtime

Wednesday May 12th, 2010

Working overtime may be bad for the heart, researchers warn today.

The finding may simply reflect the nature of those who volunteer for overtime - who may be the most stressed and driven people, according to experts.

Cathy Ross of the British Heart Foundation, said: "If we're stuck in the office we've less time to relax, get a good night's sleep, and take enough physical activity, all of which have been found to help reduce stress levels and protect against heart disease."

She added: "This study raises further questions about how our working lives can influence our risk of heart disease. Although the researchers showed a link between working more than 3 hours overtime everyday and heart problems the reasons for the increased risk weren't clear.

"The researchers suggest a number of reasons - hidden high blood pressure, reduced sleeping hours and psychological stress. These may affect the mechanisms that cause heart disease, but it could simply be that working long hours means we've less time to look after ourselves."

The new results come from an analysis of 6,014 men and women, aged 39 to 61, who were followed for about 11 years in the Whitehall II study. There were 369 cases of fatal coronary heart disease, non-fatal heart attacks, or angina.

Working three to four hours overtime on top of a seven-hour day was linked to a 60 per cent higher rate of these heart problems than among people who did not work overtime.

Dr Marianna Virtanen of the Finnish Institute of Occupational Health, Helsinki, Finland, and colleagues report their findings in the European Heart Journal.

She said: "The association was independent of a range of risk factors that we measured at the start of the study, such as smoking, being overweight, or having high cholesterol." But "more research is needed before we can be confident that overtime work would cause coronary heart disease".

The researchers believe that working overtime may be related to "type A behaviour", or a tendency to be hostile, competitive, tense and time-conscious. People in this category are known at have a higher heart risk.

The link may also be caused by greater depression and anxiety in those working overtime, or a tendency to work through illness and not seek medical help.

In an editorial, Professor Gordon McInnes of Glasgow University, UK, adds: "Overtime-induced work stress might contribute to a substantial proportion of cardiovascular disease."

* Meanwhile another study today says shift-workers' employers may benefit from their drinking coffee and cola or energy drinks.

The new analysis says caffeine can help reduce errors during night-working.

Katharine Ker,of the London School of Tropical Medicine, Lndon, UK, studied 13 trials of caffeine for the Cochrane project. She says workers, as well as their employers, may benefit if improved concentration reduces injury rates.

Virtanen, M. et al. Overtime work and incident coronary heart disease: the Whitehall II prospective cohort study. European Heart Journal, published online May 12, 2010.

McInnes, G. T. Overtime is bad for the heart. European Heart Journal, published online May 12, 2010.

Ker K, Edwards PJ, Felix LM, Blackhall K, Roberts I. Caffeine for the prevention of injuries and errors in shift workers. Cochrane Database of Systematic Reviews 2010, Issue 5. Art. No.: CD008508. DOI: 0.1002/14651858.CD008508

Tags: Diet & Food | Europe | Fitness | Heart Health | UK News

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