New Research Links Good Sleep to Good Health

Heart disease. After tracking more than 58,000 Chinese men and women age 45 and older in Singapore, researchers found that during their 13-year study, those getting less than five hours of sleep—or more than nine hours—were up to twice as likely to die from heart disease compared with those getting about seven hours a night. Researchers who published their study last year in the American Journal of Epidemiology found this link independent of known risk factors such as smoking and obesity.

Colds and respiratory illness. The less sleep you get, the more vulnerable you are to the common cold. In addition, a recent team from three universities—Carnegie Mellon, the University of Pittsburgh and the University of Virginia—wrote in Archives of Internal Medicine that people who get less than seven hours per night are three times more likely to develop respiratory illness after a cold than those sleeping eight hours or more. Researchers suspect that lack of sleep interferes with infection-fighting mechanisms.

Obesity. Emerging evidence suggests that getting too little sleep may play a key role in an expanding waistline, which factors into heart disease, diabetes and other health problems. “We know there’s more daytime snacking in people who are sleep-deprived,” notes Verma, “because sleep helps regulate two hormones affecting appetite—ghrelin, which tells the brain you need to eat more, especially cravings for poor carbohydrate choices; and leptin, which tells the brain that you’re full. People who don’t sleep enough have higher levels of ghrelin.”

In one study presented at a meeting of sleep specialists last year, University of Chicago researchers noted that participants limited to 5.5 hours of sleep per night consumed about 200 extra calories per day on snacks alone compared with those who had “normal” sleep patterns. Other research has found that people who sleep more than nine hours a night are also more likely to be obese.

Diabetes. People who sleep less than six hours a night appear to have a higher risk of developing abnormal blood sugar levels that can lead to type 2 diabetes, according to a study presented March 11 at an American Heart Association conference in Palm Harbor, Fla. Researchers followed 1,455 people over six years and found that those who slept less than six hours a night were nearly five times more likely to develop impaired fasting glucose than those tho slept six to eight hours a night.

So how can you better ensure a sound night’s sleep? Some suggestions from Verma:

    * Get a checkup. Both insomnia and daytime sleepiness are often caused by an underlying medical problem, says Verma. Common culprits include anxiety and depression, as well as sleep apnea—which is “very common, but often undiagnosed, in post-menopausal women.”

    * Avoid sleep aids. Prescription medications offer temporary relief, but can quickly lose their efficacy. “Then they produce a rebound effect so you need them to sleep well,” say Verma. They also can cause dangerous interactions with other medications and some can cause drug dependence.

    * Practice stress management. Studies show that adults who regularly practice tai chi, yoga or other types of mood-boosting exercise sleep better. “Strong family networks and other social interactions also help improve sleep,” notes Verma.

    * Nix the nightcap. Avoid alcohol within four to six hours of bedtime; it can cause “fragmented” sleep when metabolized. Caffeine can also keep you up and worsen restless legs syndrome, which triggers a powerful urge to move your legs (waking you and your bedmate) and can cause a tingling or burning sensation.

    * Time your naps. If you regularly take daytime naps, limit them to 15 to 30 minutes. Any longer and they’ll likely affect nighttime sleep or could indicate an underlying health problem.

 
Sid Kirchheimer writes about consumer and health issues.