Long Hours, Less Sleep Linked to Heart Attacks
Overtime work and long hours may be risk factors for acute myocardial infarction (AMI): During Japan's 1980s economic boom, an increase in deaths related to long hours and less sleep was reported.
To determine the relationship between hours worked, hours slept, and AMI risk in Japanese men, 260 40- to 79-year-old men who had suffered nonfatal AMI were compared to 445 matched controls.
From 1996-1998, subjects participated in interviews on work and lifestyle factors.
Longer hours at work, less sleep per night, and fewer days off were all linked to higher risk of AMI, with combinations of these factors and recent occurrences further increasing risk. Men who slept five hours or less per night at least two days each week had two-to-three times the risk for AMI compared to men sleeping more; men who worked 61 or more hours per week doubled their risk for AMI, compared to those working 40 hours or less weekly.
In conclusion, "Higher [AMI risk] for few days off in the past month rather than in the past year and for frequent lack of sleep in the past week rather than in the past year indicate that sleep deprivation and lack of rest in the very recent past may exert a trigger effect on the onset of AMI."
Liu Y, Tanaka H. Overtime work, insufficient sleep, and risk of non-fatal acute myocardial infarction in Japanese men. Occupational and Environmental Medicine
2002:59, pp. 447-451. http://oem.bmjjournals.com