11-Hour Day Raises Heart Disease Risk By 67% Compared To 8-Hour Day

Editor's Choice
Academic Journal
Main Category: Heart Disease
Also Included In: Cardiovascular / Cardiology;  Public Health;  Anxiety / Stress
Article Date: 05 Apr 2011 - 7:00 PST


If you work 11-hours a day average you will probably earn more than your 8-hour a day colleagues, but your risk of developing heart disease will be 67% higher, European researchers reveal in a study published in Annals of Internal Medicine. The researchers believe doctors should include data on a patient's working hours when listing risk factors for heart disease, such as smoking status, total body weight, diabetes, and blood pressure.

Professor Mika Kivimäki, from University College London, and team gathered data on over 10,000 British civil servants since 1985 (Whitehall II Study). 7,095 of them had no symptoms of heart disease, angina and no medical histories of heart disease at the start of the study, they were all full-time working men and women - the researchers focused on these people.

They gathered data on heart disease risk factors, such as cholesterol levels, blood pressure, age, smoking status and diabetes. Participants reported on their daily schedules, including how many hours they worked on an average weekday - including work brought home. 11-year follow up data was gathered and analyzed, including how many had heart attacks and developed other cardiovascular diseases, results of medical screenings which occurred every five years, health records and hospital data.

They found that by adding how many hours an individual generally worked each week to their list of risk factors, it was easier for doctors to predict heart disease risk - a 5% improvement in their prediction rate.

Doctors commonly use the Framingham risk model to determine an individual's risk for developing coronary heart disease over a ten-year period. This risk model includes several factors, including blood pressure, smoking status, lipid levels, etc., but no psychological factors, such as workplace stress.

Kivimäki said:

"We have shown that working long days is associated with a remarkable increase in risk of heart disease. Considering that including a measurement of working hours in a GP interview is so simple and useful, our research presents a strong case that it should become standard practice. This new information should help improve decisions regarding medication for heart disease. It could also be a wake-up call for people who overwork themselves, especially if they already have other risk factors."

"Using Additional Information on Working Hours to Predict Coronary Heart Disease - A Cohort Study"
Mika Kivimäki, PhD; G. David Batty, PhD; Mark Hamer, PhD; Jane E. Ferrie, PhD; Jussi Vahtera, MD, PhD; Marianna Virtanen, PhD; Michael G. Marmot, MD, PhD; Archana Singh-Manoux, PhD; and Martin J. Shipley, MSc
Annals of Internal Medicine April 4, 2011 vol. 154 no. 7 457-463

Written by Christian Nordqvist
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

• Additional
• References
• Citations