LONDON • People working long hours are more likely to have a stroke, according to an analysis of more than half a million people.
The data, published in The Lancet medical journal, showed the chance of a stroke increased beyond the traditional 9am to 5pm. The link is uncertain but researchers' theories include a stressful job and its damaging impact on lifestyle.
Compared with people who logged a 35- to 40-hour week, those working up to 48 hours had a 10 per cent higher risk, while for those working 49 to 54 hours, the risk jumped to 27 per cent. Working 55 hours or more a week increased the risk of having a stroke by 33 per cent, the study showed.
Dr Mika Kivimaki, a professor of epidemiology at University College London, said that in the 35- to 40-hour group, there were fewer than five strokes per 1,000 employees per decade. That increased to six strokes per 1,000 employees per decade in those working 55 hours or more, reported BBC News.
Dr Kivimaki and colleagues analysed data from 25 studies involving 603,838 men and women from Europe, the United States and Australia who were followed for an average of 8.5 years.
He admitted that researchers were still at the early stages of understanding what was going on but suggested that physical inactivity, high alcohol consumption and repetitive stress all enhance risk.
"Health professionals should be aware that working long hours is associated with a significantly increased risk of stroke," Dr Kivimaki said.
Dr Tim Chico, a consultant cardiologist based at the University of Sheffield, advised people to increase physical activity and improve their diet while working.
Among developed countries, Turkey has the highest proportion of individuals working more than 50 hours a week (43 per cent) while the Netherlands has the lowest (less than 1 per cent).