WASHINGTON
The number of veterans receiving disability benefits for a sleeping disorder has increased 61% in the past two years and now costs taxpayers more than $500 million per year, according to Veterans Affairs data released to USA TODAY.

More than 63,000 veterans receive benefits for sleep apnea, a disorder that causes a sleeping person to gasp for breath and awaken frequently.
It is linked to problems ranging from daytime drowsiness to heart disease.
The top risk factor for contracting the disorder appears to be obesity, though a sleep expert at the VA and a veteran's advocacy organization cite troops' exposure to dust and smoke in places such as Afghanistan and Iraq as contributing factors.

More claims are likely to be made in the future as Baby Boomers age and get heavier, says Max Hirshkowitz,
director of the Sleep Disorder Center at the Houston Veterans Affairs Medical Center.

Veterans are four times more likely than other Americans to suffer from sleep apnea, Hirshkowitz said.
About 5% of Americans have the disorder, he said, compared with 20% of veterans.

Veterans benefits for sleep apnea are more generous than those for workers in the private sector, records show.
For example, Elaine Fischer, a spokeswoman for the Washington State Department of Labor and Industries, which handles workers' compensation in that state, said the department is not aware of any occupational exposure that would cause sleep apnea.
"We're unaware of it being directly caused by something work related," she said.

In 2007, Congress asked the Department of Veterans Affairs to pay closer attention to sleep apnea among veterans.
Greater awareness of the disorder has prompted more veterans to seek treatment, Hirshkowitz said.
The result has been a sharp increase in claims and disability payments to veterans, according to data provided to
USA TODAY by Veterans Affairs:

The number of veterans claiming sleep apnea as a disability has jumped to 63,118 in 2010 from 39,145 in 2008, a 61% increase.

Payments to apnea patients with a disability rating of 50 by far the largest group receiving benefits rose to a minimum of
$534 million in 2010 from $306 million in 2008.
The minimum payment for a disability with a rating of 50 is $9,240 a year but increases if a veteran is married and has children.

The Social Security Administration recognizes sleep apnea as a disability.
It pays benefits to those who can't work because of a disability that is likely to last at least one year or will kill them.
The VA says veterans, however, can receive benefits and hold jobs.

Some veterans may be predisposed to sleep apnea, Hirshkowitz said, because many are built like football players.
They're big men, and as they age, many "become sedentary" and gain "an enormous amount of weight," he said.
"When you get to middle age or late middle age your level of exercise does not maintain particularly when you have knee problems and hip problems."

Daniel Chapman, a psychiatric epidemiologist at the Centers for Disease Control and Prevention, agreed:
"I really can't think of a reason other than what's happening in the general population, which is that we're growing
increasingly obese."

Chapman and Hirshkowitz said some sleep apnea cases may be caused by exposure to toxins from smoke or fires.

Along with increased screening, the rise in sleep apnea cases may also be due to exposure to dust, sand and grit in Iraq and Afghanistan, said Thom Wilborn, a spokesman for the Disabled American Veterans organization.

"Give a guy a rifle and put him in a desert, and he's going to suffer some respiratory issues," Wilborn said.

Losing weight can help some people with sleep apnea, Hirshkowitz said. Though he notes that some thin men and some women also have the disorder.

Veterans with a disability rating of 50 require breathing assistance with the airway pressure device, the VA said. The breathing machines work well, Hirshkowitz said, and can prevent veterans from developing more serious heart and lung problems.

Contributing: Alison Young