If you work long hours, you may be at increased risk for cardiovascular disease and should thus be extra vigilant in con­trolling risk factors such as high blood pres­sure or undesirable cholesterol levels.

In a study in the Journal of Occu­pational and Environmental Medicine, researchers from the University of Texas followed a representative sample of 1,926 initially healthy American workers for 25 years. They found a dose-response relation­ship between average hours worked per week for at least 10 years and increasing risk of heart attack, stroke, hypertension, angina, and other cardiovascular events.

Compared to working 45 hours per week, working…

• 55 hours per week entailed a 16 per­cent higher risk.
• 60 hours, a 35 percent higher risk.
• 65 hours, a 52 percent higher risk.
• 70 hours, a 74 percent higher risk.
• 75 hours or more, double the risk.

The researchers controlled for age, sex, education, race/ethnicity, and pay status.

Most, but not all, previous studies have also found an association between long work hours and increased cardiovascular risk. It’s not known how longer work may boost the risk—perhaps by increasing stress, depres­sion, or sleep problems, for instance, or by encouraging poor eating and exercise habits.

Though the study did not evaluate this, if you work long hours by choice and like what you’re doing, you’re probably less likely to have adverse health effects. What’s more, being involuntarily unemployed or under­employed is also linked with poorer health.