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David Lombrozo was never a good sleeper. "Then I started my own company, and it got worse," said the Marietta, Ga., owner of an information-technology management company. "I got to bed later, got up earlier, wasn't eating well. I gained 15 pounds, which made me snore and woke me up even more."

As a result, Type 2 diabetes, which had been lurking in his family genes, caught up with him.

Like the 27 million other Americans afflicted with Type 2 diabetes, Lombrozo learned that sleep deprivation and diabetes feed on each other: Diabetes symptoms disturb sleep, while sleep loss contributes to diabetes. Add obesity and stress, and you have a vicious circle.

Formerly known as adult-onset diabetes, Type 2 means having too little insulin (a hormone that helps the body use sugar) and too much glucose (sugar). As Americans' average number of sleep hours has decreased, Type 2 diabetes has become more common.

Seven to nine hours of sleep per night is ideal, according to the American Diabetes Association, but 35 percent of us get less.

Thanks to diabetes complications such as restless-leg syndrome and neuropathy (nerve pain or numbness), many diabetics cannot sleep well, causing their condition to worsen. But the road to diabetes can start from the other direction, too, meaning sleep deprivation.

The No. 1 sleep enemy is apnea, a breathing interruption caused by obstructed airways.

"Sleep apnea and diabetes go hand in hand," said Dr. Florence Comite, a New York City endocrinologist. About 36 percent of Type 2 diabetics have sleep apnea, according to the diabetes association. "Sleep helps our bodies restore themselves," Comite said. "Without enough sleep, we can actually bring on diabetes."

It's all about hormones, she said, starting with insulin, the hormone that's in short supply for diabetics. Adequate sleep allows HGH (human-growth hormone) and IGF-1 (insulin-like growth factor 1) to grow cells and repair tissues. With enough sleep, the body produces leptin, the hormone that depresses the appetite. Without enough sleep, it produces more ghrelin, which stimulates the appetite.

Sleep deprivation increases cortisol, the "stress hormone" that prevents insulin from getting into the cells ("insulin resistance").

In addition to preventing sleep, apneas reduce the amount of oxygen going to the brain and heart. "The pressure from trying to breathe stretches the heart, which puts out a diuretic," explained Robert Rosenberg, DO, a Prescott Valley, Ariz., sleep specialist. "Men blame their prostates, and women blame menopause, but really it's their sleep apnea that's causing them to have to go to the bathroom at night."

Sleep apnea is more common among people who are male, older, have thick necks or sunken chins, and among those who carry their excess weight at their waists. Though being overweight elevates sleep apnea risk, even diabetics who are not obese are at risk.

If obesity is not part of the diabetes-sleep equation to start, it often becomes one. A hormone imbalance causes the diabetic to eat the wrong foods and be too tired to exercise.

"No wonder people just give up," said Dr. Charlie Seltzer, a Philadelphia obesity medicine physician who lost 75 pounds by following his own advice: "Figure out how many calories you take in, and eat less."