Sleeping Poorly and Sleep Apnea Raises Risk for Dementia

Older men who have breathing difficulties or spend less time in deep sleep may be at greater risk of brain changes that can precede dementia, a new study suggests.

Experts said the findings don’t prove that breathing disorders, including sleep apnea, lead to dementia. But they add to evidence that poor sleep may play a role in some older adults’ mental decline.

Past studies have suggested that people with certain sleep disturbances may face a greater dementia risk, the researchers note. But the reasons remain unclear.

The new findings “help to explain how sleep disturbances may actually contribute to the development of cognitive impairment and dementia,” said study leader Dr. Rebecca Gelber, of the VA Pacific Islands Health Care System in Honolulu.

Specifically, the researchers found that elderly men who had less oxygen circulating in their blood during sleep tended to show more “microinfarcts” in the brain. Microinfarcts are tiny abnormalities in brain tissue that can precede dementia.

Meanwhile, men who spent less time in slow-wave sleep — the deep, restorative stage of sleep — tended to show more atrophy in their brain tissue.