If you find it hard to get a good night's sleep, your health could be in danger. For years, physicians have known that poor sleep increases the risk for a number of serious conditions, including obesity, type 2 diabetes and heart disease.

Recent findings from a study at Duke University Medical Center suggest that the negative health consequences of poor sleep — measured by the time it takes to fall asleep, the time spent asleep and the degree of awakening during the night — are significantly greater for women than for men.

In the Duke study, which included 210 healthy middle-aged adults, researchers found that in women, poor sleep was strongly linked to greater feelings of hostility, depression and anger. Women who slept poorly were also found to have higher blood levels of C-reactive protein and other inflammatory compounds associated with an increased risk for heart disease.

The Duke scientists found that the length of time it takes a person to fall asleep was the most important predictor of health risk. Women who reported taking a half hour or longer to fall asleep had the worst health-risk profiles.

Earlier research conducted at Warwick Medical School yielded similar results. In a study of more than 6,500 men and women, researchers noted that women who slept five hours or less each night were twice as likely to suffer from hypertension as women who slept at least seven hours per night. The researchers saw no such difference in men.

There's little doubt that insufficient sleep is linked to weight gain. In a 16-year study that included more than 68,000 middle-aged women enrolled in the Nurses' Health Study, women who slept an average of five hours per night were 32 percent more likely to experience a weight gain of 33 pounds or more than those women who typically slept at least seven hours each night.

The researchers took a closer look at the women's diets and exercise patterns to see if they could explain the dramatic differences in weight gain. Previous studies have shown that after just a few days of sleep restriction, hormones that control appetite cause significant increases in hunger and can trigger overeating.

Surprisingly, the women who slept five hours or less ate fewer calories each day than the women who slept seven hours or more. After examining exercise habits, the researchers did not find any significant differences in physical activity levels that could explain why the women who slept less weighed more.

Based on the results of the study, the researchers concluded that sleep restriction may promote weight gain by slowing the basal metabolic rate, or the rate at which the body burns calories at rest.

While many women experience significant sleep disturbances during menopause, hot flashes and night sweats aren't always to blame for poor quality slumber. The results of a new study published in the February 2008 issue of Harvard Women's Health Watch suggest that some of the sleep problems that women typically attribute to hot flashes may instead be caused by serious sleep disorders, including sleep apnea.

To determine the cause of poor sleep during the menopausal transition, researchers analyzed the sleep of 102 women who reported having trouble sleeping. The scientists found that menopause alone wasn't always the culprit: 53 percent of the women suffered from some type of sleep disorder.

Obstructive sleep apnea is one sleep disorder known to be more common in women after menopause. The elevated risk is thought to be due in part to menopause-related weight gain, but it also appears to be related to changing hormone levels.

With this in mind, women should be aware that simply treating the symptoms of menopause, including hot flashes and night sweats, doesn't always bring about improvements in the quality of quantity of sleep. Likewise, poor sleep may persist long after the menopausal transition is complete.

With each passing year, sleep restriction increases a woman's risk for emotional and physical health problems, including depression, obesity, diabetes and heart disease. The end result is often a dramatic reduction in quality of life.

The good news is that upon diagnosis, women with sleep disorders typically respond very well to medical treatment. For women troubled with poor sleep, making a doctor's appointment is often the most important step in the quest for a good night's rest.

Dr. Rallie McAllister is a board-certified family physician, speaker and the author of several books, including "Healthy Lunchbox: The Working Mom's Guide to Keeping You and Your Kids Trim." Her website is www.rallieonhealth.com. To find out more about Rallie McAllister, M.D., and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com.