New York :

People who work long hours are more likely to face the risk of developing high blood pressure than those who do not.

The finding comes from a 2001 telephonic survey of over 24,000 California workers analysed by Haiou Yang and colleagues at the University of California, reported the science portal News-Medical.

The majority of research previously done on the connection between long working hours and hypertension has focused on Asian workers, particularly the Japanese, whose high work pressure ethos has resulted in the phenomenon known as Karoshi, or sudden death from overwork. But in recent years, the average workload in the US has increased and now Americans work longer hours than the Japanese do.

The survey found that those who worked 40 hours per week were 14 per cent more likely to have high blood pressure than people who worked 39 hours or less. Further, the risk for hypertension was 17 per cent greater in those working 41-50 hours weekly, and 29 percent higher in those working 51 hours or more.

The researchers say the risk of having high blood pressure rose steadily with the number of hours worked and persisted even after adjusting factors such as socio-economic status and body weight.

It was also found that hypertension was more common among clerical and unskilled workers than among professionals. According to the researchers, this suggests that occupations requiring more challenging and mentally active work may have a protective effect against hypertension.