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With over 30% of French people over the age of 65 suffering from sleep apnea, scientists are concerned. More and more studies suggest that sleep-related respiratory disorders increase the risk of developing Alzheimer’s disease.

 

Sleep disorders may be responsible for the development of several serious diseases

We spend around a third of our lives asleep, with French people sleeping for an average of 7 hours and 5 minutes per night during the week. Sleep is a normal physiological need and, above all, is essential for good health in humans.1 Disturbed sleep can have detrimental effects on mental health, but also on physical health, with an increased risk of developing inflammatory, cardiac and metabolic diseases, in particular.2 According to a meta-analysis conducted by Italian researchers and grouping together 10 studies with more than 107,000 participants altogether, sleeping for an average of less than 6 hours each night may significantly increase the risk of type 2 diabetes.3

Almost a third of French people over the age of 65 suffer from sleep apnea. Clinically, the condition is characterized by severe snoring, restless sleep, jerky breathing and night-time awakenings. It is caused by obstruction of the upper airways. Like other sleep disorders, sleep apnea is often associated with other serious health problems, such as cardiovascular diseases.

 

Scientific studies confirm the correlation between sleep apnea and neurodegenerative Alzheimer’s disease

An American study including people over the age of 60 suggests that poor quality sleep may result in an accumulation of Tau protein in the brain. This protein is thought to be responsible for the destruction of neurons in Alzheimer’s disease. During the study, the sleep of the participants was recorded by electroencephalography (EEG). In almost 80% of them, the Tau concentration was shown to be higher in the brain when sleep was disturbed.4

A recent study published by INSERM also reports a correlation between sleep apnea and Alzheimer’s disease. According to the researchers, there is more and more evidence to suggest that these respiratory disorders during sleep significantly increase the risk of developing Alzheimer’s disease. The scientists included 157 participants without cognitive disease in their study. They had an average age of 69 years and 63% were women. 75% of the sample suffered from sleep apnea. The researchers observed that the people with sleep-disordered breathing demonstrated a more marked accumulation of beta-amyloid protein on imaging. This protein forms the amyloid plaques that can be responsible for the first signs of Alzheimer’s disease.5

However, INSERM scientists are keen to reassure us. They point out that sleep apnea increases the risk of developing Alzheimer’s disease but does not systematically trigger it. They therefore suggest that there is a need to detect sleep apnea early in elderly people with no cognitive disorders in order to reduce their risks of developing Alzheimer’s disease.

 

Sources

  1. Richeux, Vincent. Sommeil : La santé vient en dormant. Science&Santé(Paris), 2017, N° 35, p. 25-35

  2. Ayas NT, White DP, Manson JE, Stampfer MJ, Speizer FE, Malhotra A, Hu FB. A prospective study of sleep duration and coronary heart disease in women. Arch Intern Med. 2003 Jan 27;163(2):205-9. doi: 10.1001/archinte.163.2.205. PMID: 12546611.

  3. Cappuccio FP, D'Elia L, Strazzullo P, Miller MA. Quantity and quality of sleep and incidence of type 2 diabetes: a systematic review and meta-analysis. Diabetes Care. 2010 Feb;33(2):414-20. doi: 10.2337/dc09-1124. Epub 2009 Nov 12. PMID: 19910503; PMCID: PMC2809295.

  4. Lucey BP, McCullough A, Landsness EC, Toedebusch CD, McLeland JS, Zaza AM, Fagan AM, McCue L, Xiong C, Morris JC, Benzinger TLS, Holtzman DM. Reduced non-rapid eye movement sleep is associated with tau pathology in early Alzheimer's disease. Sci Transl Med. 2019 Jan 9;11(474):eaau6550. doi: 10.1126/scitranslmed.aau6550. Erratum in: Sci Transl Med. 2020 Jan 8;12(525): PMID: 30626715; PMCID: PMC6342564.

  5. André C, Rehel S, Kuhn E, Landeau B, Moulinet I, Touron E, Ourry V, Le Du G, Mézenge F, Tomadesso C, de Flores R, Bejanin A, Sherif S, Delcroix N, Manrique A, Abbas A, Marchant NL, Lutz A, Klimecki OM, Collette F, Arenaza-Urquijo EM, Poisnel G, Vivien D, Bertran F, de la Sayette V, Chételat G, Rauchs G; Medit-Ageing Research Group. Association of Sleep-Disordered Breathing With Alzheimer Disease Biomarkers in Community-Dwelling Older Adults: A Secondary Analysis of a Randomized Clinical Trial. JAMA Neurol. 2020 Jun 1;77(6):716-724. doi: 10.1001/jamaneurol.2020.0311. PMID: 32202593; PMCID: PMC7091393.