The study found that people with sleep breathing problems were diagnosed with mild cognitive impairment (MCI) an average of nearly 10 years earlier than people who did not have sleep breathing problems.
The medical histories for 2,470 people ages 55 to 90 were reviewed by a team of researchers led by Dr Ricardo Osorio of NYU Langone Medical Center for the study.
Participants were categorised as either free of memory and thinking problems, in early stages of MCI, or with Alzheimer’s disease.
They were also grouped into people with sleep breathing problems and without sleep breathing problems.
Those who suffered from conditions such as snoring and sleep apnea were then put into two sub-categories: people with sleep breathing problems who had received treatment and people with sleep breathing problems who hadn't received treatment.
When researchers examined people who developed MCI or Alzheimer’s disease during the study, those with sleep breathing problems developed MCI at an average age of 77, compared to an average age of 90 for those who did not have sleep breathing problems.
Those who had sleep breathing problems also developed Alzheimer’s disease five years earlier than those who did not have sleep breathing problems, at an average age of 83 versus 88.
“Abnormal breathing patterns during sleep such as heavy snoring and sleep apnea are common in the elderly, affecting about 52% of men and 26% of women,” Osorio commented on the study.
The good news is that treating a sleep breathing disorder could reduce the risk of memory decline.
The researchers found that people who treated their sleep breathing problems with a continuous positive airway pressure machine (CPAP) were diagnosed with MCI about 10 years later than people whose problems were not treated - or at age 82 instead of age 72.
“The age of onset of MCI for people whose breathing problems were treated was almost identical to that of people who did not have any breathing problems at all,” Osorio said.
“Given that so many older adults have sleep breathing problems, these results are exciting. We need to examine whether using CPAP could possibly help prevent or delay memory and thinking problems.”
The study follows previous research that suggested sleep apnea could also increase an individual's risk of cancer.
In 2014, researchers at the University of Sydney Nursing School in Australia found that people with moderate or severe sleep apnea may be two and a half times more likely to develop cancer than people without sleep apnea.
Cancer mortality was also found to be over three times more common in those with sleep apnea than with no sleep apnea during a 20 year follow-up.
The NHS advise anyone who believes they may be suffering from sleep apnea to visit their GP.
The study was published in medical journal American Academy of Neurology.