According to a recent poll by the National Sleep Foundation, 60% of Americans experience some sleep problems and only 37% get at least the recommended eight hours of sleep a night. What many may not realize, however, is that sleep problems and sleep deprivation can have a negative impact on a person’s health. For instance, previous research looking for links between sleep duration and cardiovascular disease has found that even partial sleep deprivation over a short period of time can increase blood pressure , impair glucose tolerance , and increase stress hormones in the body.

New research in the January 27, 2003 issue of the Archives of Internal Medicine took previous research one step further by studying a large number of women, adjusting for numerous factors that might influence sleep or risk of heart disease , and following the study participants over a long time period. The study results suggest that there is a significant link between sleep duration and cardiovascular disease in women.

About the Study

Researchers from Brigham and Women’s Hospital and Harvard Medical School studied 71,617 women (aged 45-65 years) who had no previous history of cardiovascular disease and were enrolled in the Nurses’ Health Study. The women were mailed questionnaires in 1986 that asked about daily sleep duration. Ten years later, the researchers reviewed medical records, the National Death Index, and other documentation to determine which women had experienced a nonfatal heart attack or fatal coronary heart disease during the study period. The women were then classified according to the reported daily sleep duration, and researchers looked for possible links between heart disease and the amount of sleep these women reportedly got each night.

The Findings

There were 934 cases of coronary heart disease (271 fatal and 663 nonfatal) over the study period. After making adjustments to account for known coronary risk factor— smoking , age, and body mass index among others—the researchers found that the 5% of the women in the study group who had five or fewer hours of daily sleep had a 5%-84% (avg. 39%) increased risk of coronary heart disease when compared to those who had eight hours of daily sleep (reference group).

In addition, those who slept nine or more hours daily—5% of the study group—had a 2%-85% (avg. 37%) increased risk of coronary heart disease compared to the reference group. While the increase in risk is modest, this result is significant enough to warrant a closer look at the influence of sleeping habits on cardiovascular disease and health in general. Based upon previous research, it’s reasonable to speculate that this type of research and subsequent interventions would also be important in men.

How Does This Affect You?

Although this study suffers from the usual biases associated with survey data and its results cannot be used to conclude that too much or too little sleep is the cause of adverse cardiovascular events, it does raise the possibility that sleep problems can affect your health. The National Sleep Foundation recommends that you talk to your doctor if sleep problems persist for longer than a week, or if sleepiness interferes with the way you feel or function during the day. Here are a few tips from the National Sleep Foundation to help you get the sleep you need.

  • Avoid caffeine, nicotine and alcohol in the late afternoon and evening —Caffeine and nicotine can delay your sleep, and alcohol may interrupt your sleep later in the night.
  • Establish a regular, relaxing bedtime routine that will allow you to unwind and send a "signal" to your brain that it's time to sleep. Avoiding exposure to bright light before bedtime and taking a hot bath can also help.
  • Make your sleep environment as pleasant, comfortable, dark, and quiet as you can.
  • Try not to nap during the day if you have trouble sleeping at night.
  • Exercise regularly, but do so at least three hours before bedtime —Working out too close to bedtime may actually keep you awake because your body has not had a chance to cool down.
  • Don't use your bed for anything other than sleep or sex.
  • If you can't go to sleep after 30 minutes, don't stay in bed tossing and turning —Involving yourself in a relaxing activity, such as listening to soothing music or reading, can help you to feel sleepy. Do not watch television or engaged in other potentially stimulating activities.