Obstructive sleep apnoea worsening inflammation and oxidative damage in Alzheimer's disease patients

Obstructive sleep apnoea worsens inflammation and oxidative damage (the deterioration of cells) in patients with Alzheimer's disease, according to research led by the Cognition and Behaviour Study Group at the Institute for Research in Biomedicine of Lleida (IRBLleida) and the University of Lleida (UdL). "Our study shows that the level of severity of obstructive sleep apnoea can have a direct impact on the biological processes of Alzheimer's disease. Considering that approximately 40% of Alzheimer's patients also suffer from severe obstructive sleep apnoea, our results highlight the importance of treating obstructive sleep apnoea," explained the article's first author and research fellow, Leila Romero el Khayat.

The research, published in the Journal of Inflammation Research, found that a panel of genes involved in inflammation and redox metabolism in the blood of patients with mild Alzheimer's disease and severe obstructive sleep apnoea were more activated. Moreover, some of these genes correlate with parameters of polysomnography, a test used to diagnose obstructive sleep apnoea. Thus, the study concludes that obstructive sleep apnoea can worsen inflammation and oxidative damage that are already altered in Alzheimer's disease patients. The research looked at 40 Alzheimer's patients, differentiating between those with severe and non-severe obstructive sleep apnoea based on a sleep study (polysomnography).

Obstructive sleep apnoea is a common disorder in patients with Alzheimer's disease. For this reason, this study has investigated how intermittent hypoxia (lack of oxygen during sleep) caused by obstructive sleep apnoea may contribute to disease progression through oxidative stress and inflammation.

In addition to the Cognition and Behaviour Study Group of the IRBLleida, the study has been done in collaboration with the Son Unit of the University Hospital of Santa Maria de Lleida, the translational research group in respiratory medicine of the IRBLleida and the Victor Babes National Institute of Pathology of Romania.

'Looking to the future, it would be very important to assess whether the treatment of obstructive sleep apnoea can reverse the overexpression of these genes in Alzheimer's patients and whether this would have any clinical relevance,' explained researcher-in-training Leila Romero el Khayat.

'We still lack evidence to see if the treatment can reverse these pathophysiological changes, improve cognition or normalise biomarkers related to Alzheimer's disease,' said Romero el Khayat. "Our results open up new possibilities for the diagnosis of severe obstructive sleep apnoea in patients with Alzheimer's disease. Currently, polysomnography is the most reliable form of diagnosis in patients with Alzheimer's disease, but it is a complicated and expensive method. Therefore, it would be more convenient and less expensive to do it through blood tests," he concluded.

The research has been made possible thanks to funding from the Department of Health (PERIS 2019 SLT008/18/00050), the TV3 Marathon Foundation (464/C/ 2014), the Agency for Management of University and Research Grants (AGAUR) (2021SGR 00761), the Diputació de Lleida (PP10605 - PIRS2021), the Instituto de Salud Carlos III and the European Union (ERDF/ESF, 'Investing in your future' and 'A way to build Europe') (PI22/01687).

Article: Romero-ElKhayat L, Dakterzada F, Huerto R, Carnes-Vendrell A, Mínguez O, Pujol Sabaté M, Targa A, Barbé F, Milanesi E, Dobre M, Manda G, Cuadrado A, Piñol-Ripoll G. Inflammatory and Redox Blood Gene Expression Fingerprint of Severe Obstructive Sleep Apnoea in Patients With Mild Alzheimer's Disease. J Inflamm Res. 2025 Feb 4;18:1609-1621. doi: 10.2147/JIR.S475776. PMID: 39925924; PMCID: PMC11806709.

; PMCID: PMC11806709.