All sleep apnea patients appeared to be at risk of crashing their cars. The problem wasn't limited to those with severe apnea.
"It didn't matter how severe your sleep apnea was. We found that you still have the same increased risk even if you have mild sleep apnea," Mulgrew says.
And patients seemed unable to tell when they were at greater risk. Patients who said they drove even when they felt sleepy were no more likely than other sleep apnea patients to wreck their cars.
The results of the study were so striking that Mulgrew now carefully asks his sleep apnea patients about their driving histories and about any "near misses" they might be having. He is much more likely to recommend the most effective sleep apnea treatment -- a continuous positive air pressure or CPAP device -- to patients with driving problems, even if their sleep apnea is relatively mild.
Sleep Apnea and Diabetes
To see whether the two conditions were related, the researchers kept track of nearly 600 sleep apnea patients for up to six years. Compared with similar men without sleep apnea, the patients were more than two-and-a-half times more likely to develop diabetes.
The more severe the sleep apnea, the higher the patients' risk of diabetes.
"We know that by measuring markers in the blood that the body of a person with sleep apnea is in a highly inflammatory, highly excitatory state," Botros says. "This state increases stress hormones, and we think the insulin-making pancreatic beta cells are affected."
Botros and colleagues are now looking at whether CPAP treatment can reduce sleep apnea patients' diabetes risk.
Sleep Apnea and Pregnancy Complications
Sleep apnea is more common among obese people. But the extra weight gain during the third trimester of pregnancy often puts a woman at risk of sleep apnea, says Hatim Youssef, DO, of the University of Medicine & Dentistry of New Jersey-Robert Wood Johnson Medical School.