People who don’t get enough sleep risk getting fat.
In a Chicago’s University study, men who were limited to four hours of nightly sleep had decreased levels of leptin, a hormone that signals the body you’re full.
- “Not getting enough sleep leads to increased appetite and a craving for carbohydrate-based foods,” says Dr. James MacFarlane, assistant professor of psychiatry at the University of Toronto and lab director of the Centre for Sleep and Chronobiology. “It pushes many people towards weight gain.”
Heart Matters
In a recent study by Dr. Najib Ayas, assistant professor of medicine at the University of British Columbia, women who slept less than six hours a night had a 39 percent higher risk of heart attack than those who slept eight hours.
Previous researches have linked sleep deprivation to heart problems in men. One accused may be inflammation of the arteries, a condition that has been linked to even mild sleep loss.
Researches have shown that one of the immediate effects of sleep loss is increased activity in cytokines - immune-system molecules secreted to fight disease.
When increased, they indicate there is something wrong, as if the body is being attacked. “It immediately causes increased blood pressure and inflamed arteries”. “If you undergo from chronic sleep loss, you are at higher risk for stroke and heart disease.”
Sleeplessness seems to target the human heart in particular. Even the latest star on the heart-disease front, C-reactive protein—perhaps the body’s best predictor of heart attack and stroke—is elevated in sleep-deprived lab volunteers.
- C-reactive protein is produced by the liver as part of the body’s immune response and can indicate damage to arterial walls.
The Diabetes Link
Sleep scientist at the University of Chicago recently monitored 27 sleepers aged 23 to 42 in their homes. Thus one group slept just over five hours on weeknights; the other, eight.
The scientist then tested the volunteers for insulin resistance—how well the body uses the insulin to regulate sugar levels in the body (the greater one’s resistance, the less effectively the body uses insulin).
The results were surprising. Those with five hours sleep had 50 percent more insulin resistance than those with eight hours. Studies found that the results were comparable to what you’d expect to see in people decades older.
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