Sleeping Habits May Be Related to Heart DiseaseSkimping on sleep raises heart risk for women, but study finds that too much sleep is bad, too< January 28, 2003 > Skimping on sleep seems to be a popular survival strategy among women with hectic schedules. But a new study suggests you are not doing your health any favors when you do not get enough sleep. In fact, you may be putting yourself at risk for a heart attack. Researchers from Brigham and Women's Hospital in Boston found that women who sleep five or fewer hours have an 82 percent higher risk of heart attack than those who sleep the suggested eight hours a night, even after adjusting for age differences. Women who sleep six hours a night boost their heart attack risk by 30 percent. But the researchers found that too much sleep is not good, either. Those women who slept nine or more hours a night increased their heart disease risk by 57 percent. The research, which evaluated some of the 121,700 women enrolled in the well-known Nurses' Health Study and followed them for 10 years, is published in a recent issue of the Archives of Internal Medicine. "I don't think the study is definitive per se, but suggestive," says Dr. Najib T. Ayas, an assistant professor of medicine at the University of British Columbia, who conducted the research while on faculty at Brigham and Women's Hospital. So while Ayas cannot yet prove cause and effect, sleep deprivation and perhaps too much sleep should be considered unhealthy habits, he says. Previous studies have found the same association between sleep deprivation and heart problems in men, Ayas says. What he and others think may be happening is that sleep deprivation can cause physiological changes—such as boosting blood pressure—that, in turn, increases heart disease risk. Only 37 percent of Americans get eight hours of sleep a night, and 31 percent get six or fewer hours of sleep, according to a recent poll from the National Sleep Foundation. For the study, Ayas and his colleagues targeted a subset group of the Nurses' Health Study—71,617 women ages 45 to 65 who did not have reported heart disease at the start of the study—and followed them over 10 years to detect any association between sleep habits and heart attacks. Each had answered questions about sleep duration in 1986, 10 years after the study began. When they adjusted not only for age but also for factors such as smoking and body mass index, the association was weaker but still present. "I think this [study] is right on the money," says Dr. Virend Somers, a professor of medicine at the Mayo Clinic who is familiar with the study. "People are not sleeping enough and we are seeing the consequences." What makes the study particularly impressive, he says, are the large numbers and the fact that the Nurses' Health Study is an established model that has yielded other important clues about cardiovascular risk, Somers says. Even though no cause and effect is proven, Somers says women and men should take sleep deprivation seriously as a health risk. "Eight hours [of sleep] would be optimal," Ayas says. If you are really strapped for time? "Seven actually wasn't too bad. If you get seven hours, your relative risk of heart disease is about the same as [getting] eight hours," Ayas says. Always consult your physician for more information. Not Getting Enough Sleep? Could Insomnia Be To Blame?If you experience difficulty falling asleep, staying asleep, or enjoying a restful night's sleep, you may be suffering from insomnia. Insomnia is defined as the perception or complaint of inadequate or poor-quality sleep because of one or more of the following:
Insomnia may be caused by many factors, including:
Guidelines That May Help Sleep Problems:
People who suffer from insomnia that lasts for more than a few days should consult a physician so that the underlying cause can be identified, if possible, then treated.
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For more information on women and heart disease, please visit the Women's Health information module on this Web site. Study Finds Silver Lining for Hormone TherapyAfter a spate of bad news about hormone therapy, new research offers a bit of good news: Hormone replacement therapy (HRT) reduces the risk of diabetes in postmenopausal women who have heart disease. But no one, including the study's authors, are suggesting that HRT be prescribed to reduce that risk. Rather, the report, which appears in a recent issue of the Annals of Internal Medicine, should trigger additional research, experts say. In the study, Dr. Alka Kanaya, an assistant professor of medicine at the University of California at San Francisco School of Medicine, and her colleagues found that HRT, including estrogen and progestin, reduced the incidence of diabetes by 35 percent during the four-year follow-up in women who had undergone natural menopause and who already had heart disease. About 16 million Americans have type 2 diabetes, a condition in which the body either makes too little insulin or cannot properly use the insulin it makes to convert blood glucose to energy. In the new study, Kanaya and her co-researchers targeted the subset of women from the trial known as HERS (Heart and Estrogen/progestin Replacement Study), in which 2,763 women with documented heart disease were assigned to take HRT or a placebo. The main HERS conclusion, that HRT did not help prevent second heart attacks, was released in 1998. In the newer study, Kanaya and her colleagues focused on the 2,029 women in the HERS trial who were free of diabetes at the outset. These women took either HRT or a placebo each day. After four years, 160 of the women developed diabetes—62, or 6.2 percent, of those on HRT and 98, or 9.5 percent, of those on a placebo. "We found that in [these] women with coronary disease, HRT reduces the incidence of diabetes by 35 percent," says Kanaya. The reduction held, she says, after controlling for such risk factors as obesity, which increases the chances of developing type 2 diabetes. The study is definitely not a reason to consider HRT to reduce diabetes risk, Kanaya says, however. "The conclusion is that this is a scientifically interesting finding that needs to be confirmed, and that the risk of hormone therapy outweighs the benefits and that it is premature to recommend the use of hormone therapy to prevent diabetes," she adds. Last summer, a national trial evaluating the benefits of HRT in healthy women was halted after experts determined women taking HRT were at increased risk for strokes and heart attacks but decreased risk for osteoporosis and colon cancer. This latest study is not the first to suggest that HRT helps reduce diabetes risk, Kanaya adds. "A lot of small studies have looked at the effect of hormone therapy on glucose levels," she says. "The data is extremely mixed." The researchers note in the report that the findings may not apply to all postmenopausal women; those in the study all had heart disease and all had undergone natural (not surgical) menopause. Always consult your physician for more information. |
