Working a lot of overtime may be good for your wallet, but it may be bad for your heart.
In a study of about 6,000 British civil servants followed for about a decade, working three or more hours of overtime a day was associated with a 60% increased risk of heart-related health issues, including heart attack, angina, and death from heart disease.
The association was seen even after researchers considered the impact of well-established heart disease risk factors like smoking, obesity, and high cholesterol.
Lead researcher Marianna Virtanen, PhD, disclosed that for the white collar civil servants in the study, working overtime was associated with more type A behavior traits like aggression, hostility, competitiveness, psychological distress, and sleep problems.
The research appears online in the European Heart Journal.
“The importance of having a good balance between work time, leisure time, and family time may be more important for the heart than has been appreciated,” she says.
Virtanen is a senior researcher and psychologist with the Finnish Institute of Occupational Health and the University College London.
Men, married workers logged more hours
The study participants were enrolled in the larger, ongoing Whitehall II health study of London-based civil service workers begun in the mid-1980s. The data on working hours were introduced in the study starting in the early 1990s.
Workers were in their late 30s to early 60s at enrollment, and they were followed for an average of 11.2 years for the overtime analysis.
During this time, 369 incidences of heart attack, angina, or heart-related death were reported.
One or two hours over the seven hours considered normal for a workday in the U.K. had little impact on heart health.
But working 10 or more hours a day was associated with a 60% increase in heart-related events.
Just over half of the study participants (54%) reported working no regular overtime, 15% reported working two extra hours a day, and 10% reported working three or four extra hours.
Men were six times more likely than women to work three or more hours of overtime a day, and married workers were almost nine times more likely than single workers to spend this much time at work.
Nearly 60% of the respondents who reported spending 10 or more hours a day at work characterised their job demands as “high,” while just 8% considered their job demands to be “low.”
Sixty-four percent of the employees who worked the longest hours reported a lot of latitude in making work decisions, while 13% reported little latitude.
Overtime has ‘Moderate’ impact on heart
Virtanen characterized the impact of overtime on heart risk as “moderate.”
“Certainly these findings need to be replicated, and we also need more research on other health outcomes, including type 2 diabetes,” she says.
Virtanen says it is not clear if the findings apply to blue-collar workers, who may have less discretion than white-collar workers over the hours they work.
The Whitehall II study is funded, in part, by the British Heart Foundation and the U.S. National Institutes of Health.
In an editorial published with the study, cardiovascular researcher Gordon T. McInnes, MD, of Scotland’s University of Glasgow, agreed that more study is needed to confirm an independent association between overtime-related work stress and cardiovascular disease.
But he noted that a growing body of research is linking longer work days with health problems, including high blood pressure.
He concludes that researchers should examine “whether interventions designed to reduce overtime work could alter the risk of cardiovascular disease.”
A new study from Denmark has linked too much pressure at work as a significant risk factor for ischemic heart disease among younger female employees, according to a new study from Denmark.
According to experts, Ischemic heart disease occurs when blood flow is restricted to the heart muscle. Often called “a silent killer,” it is estimated that as many as four million Americans may have ischemic episodes and not be aware that they have this condition because they do not experience symptoms.
Reporting in the May 6 issue of Occupational and Environmental Medicine, researchers at Glostrup University Hospital in Denmark looked at more than 12,000 female employees aged 45 to 64 who were part of the Danish Nurse Cohort Study and were followed for 15 years, from 1993 to 2008. The median age of the participants was 51.
The nurses filled out questionnaires about health, lifestyle, and occupation. The researchers took into account factors including work pressure, psychosocial work environments, job influence, occupational characteristics, such as the level of physical activity performed while on the job, and biological and behavioural factors such as smoking, body mass index, drinking alcohol, and family history of disease.
Sixty per cent of the nurses interviewed said work pressure was much too high or a little too high. Over the course of the study, 580 women were admitted to the hospital for ischemic heart disease; among those women, 369 cases were angina, 138 were heart attacks, and 73 were other cases of ischemic heart disease.
Among the study results are:
* Nurses who said their work pressure was much too high had a nearly 50% increased risk of ischemic heart disease compared with women who reported a manageable work pressure. After taking into account other risk factors for heart disease such as smoking and lifestyle, the risk fell to 35%.
* Nurses who reported work pressure being a little too high had a 25% increased risk.
* There was no significant increased risk of ischemic heart disease among nurses who reported minor or no influence on the job.
* Age was a major factor; when researchers analyzed the findings by age, only nurses younger than 51 were at significant risk of heart disease.
“It seems as if the effect of work pressure has a greater impact on younger nurses,” researchers write. “This is in agreement with findings from previous studies looking at age specific effects in both men and women. The lower risk among the older nurses may be due to other risk factors that become relatively more important with increasing age. Furthermore, vulnerable individuals may have (already) left work.”