Sleep apnoea may increase alzheimer's risk in elderly

Alzheimer's disease is a "progressive neurodegenerative disorder" that destroys memory and other important mental functions, researchers from New York University said.

The researchers reported that more sleep apnoeas lead to a greater accumulation of amino acids in the brain that further enhances the risk of alzheimer's disease over time.

"Several studies have suggested that sleep disturbances might contribute to amino acid deposits and accelerate cognitive decline in those at risk for alzheimer's disease," said Ricardo S. Osorio, Assistant Professor at New York University School of Medicine in the US.

"However, so far it has been challenging to verify causality for these associations because obstructive sleep apnoea and alzheimer's disease share risk factors and commonly coexist," Osorio added.

The researchers studied over 208 participants, aged between 55 to 90 years, with normal cognition or the process of acquiring knowledge and understanding through experiences, thoughts, and the senses. None of the participants was referred to be depressed or having any medical condition that might affect their brain function. 

The study found that more than half the participants were affected with obstructive sleep apnoea along with a rise in the symptoms of sleepiness, cardiovascular, and metabolic dysfunction and brain impairment. 

The study, published in the American Journal of Respiratory and Critical Care Medicine, also noted that the continuous positive airway pressure, dental appliances, positional therapy and other treatments for sleep apnea could delay cognitive impairment and dementia at the same time.