Increased oxygen exposure may speed Alzheimer’s

OKLAHOMA CITY, September 2, 2009 – An elderly patient goes into the hospital for routine surgery. Months later, doctors diagnose her with Alzheimer’s disease. Is this just a coincidence?

No, suggests research from the Oklahoma Medical Research Foundation, Vanderbilt University and the University of South Florida. In a new study, the scientists found evidence that exposure to high concentrations of oxygen may trigger Alzheimer’s like-disease in laboratory mice.

Researchers exposed young adult mice genetically altered to develop an Alzheimer’s-like condition to 100-percent oxygen for three hours on several occasions. They found that the rodents experienced substantial memory loss not otherwise present at their age. In contrast, young adult Alzheimer’s mice exposed to normal air showed no memory loss, nor did normal mice without predisposition to Alzheimer’s.

“These results indicate that certain environmental stresses, like high oxygen exposure, could hasten the onset of Alzheimer’s disease in some cases,” said OMRF’s Kenneth Hensley, Ph.D. Hensley co-authored the research study, which appears in Neuroreport.

“When we examined the brains of these mice,” said Hensley, “we found increases in isofurans”—products of oxygen-induced damage. “This could be part of a mechanism that spurs the onset of memory loss.”

Hensley cautioned that the results in mice may not accurately reflect the effects of exposure to high concentrations of oxygen in human patients.

“Still, this research might lead doctors and patients to discuss surgical strategies, especially in the elderly,” said Hensley. Postoperative confusion and memory problems are common in elderly patients following surgery, and some patients develop permanent dementia post-operatively.

Alzheimer’s disease is a neurological disorder characterized by progressive memory loss due to the gradual death of brain cells. It affects more than 4.5 million Americans, including 62,000 Oklahomans.

OMRF is an independent, nonprofit biomedical research institute dedicated to understanding and developing more effective treatments for human diseases. Chartered in 1946, its scientists focus on such critical research areas as Alzheimer’s disease, cancer, lupus and cardiovascular disease.

News Releases