Elderly women with sleep apnea had an 85% higher risk of developing mild cognitive impairment, a study found.

Massachusetts researchers studied a group of 298 elderly women, a third of whom had been diagnosed with sleep-disordered breathing. None of them had been diagnosed with dementia.

Five years later, investigators conducted cognition tests. They found that 45% of study participants with sleep apnea developed cognitive impairments, compared with 31% of women without sleep apnea.

The study was published in the Journal of the American Medical Association.