Molecular fingerprint identified that could contribute to sleep apnoea detection

Obstructive sleep apnoea (OSA) affects more than 20% of the adult population. However, most people are not diagnosed, as it is a costly and complex diagnostic process. In order to advance in its detection, researchers from IRBLleida, University of Lleida and the CIBER de Enfermedades Respiratorias (CIBERES) have identified a specific molecular fingerprint of this disorder in the blood of patients with suspected OSA. They have also identified a signature of blood metabolites capable of detecting sleep apnoea with 98% accuracy.

Obstructive sleep apnoea is a breathing disorder that occurs when breathing is interrupted during sleep. The immediate effects of the condition include changes in blood pressure, intermittent hypoxia, recurrent awakenings and sleep fragmentation. Despite its high incidence, most people are undiagnosed. So far, nocturnal polysomnography is the gold standard method of detection. However, this sleep study has several limitations that limit its widespread use, as it needs to be performed by trained personnel in specialised facilities.

In this work, co-directed by the Precision Medicine in Chronic Diseases Group and the Translational research in respiratory medicine group at IRBLleida, led by Manuel Sánchez, Ramón y Cajal researcher at the Faculty of Nursing and Physiotherapy of the University of Lleida, and Ferran Barbé, scientific director of CIBERES and professor at the Faculty of Medicine of the University of Lleida, and published in Biomedicine & Pharmacotherapy Journal, the researchers have analysed the metabolites and lipids circulating in the blood of 206 patients aged between 18 and 60 years, referred to the Sleep Unit for suspected sleep apnoea.

According to Lucía Pinilla, first author of the study, "we analysed the metabolites and lipids circulating in the blood to try to find biological markers that help us detect this sleep disorder, and allow us to elucidate the pathological consequences associated with this disease". In parallel, the researchers evaluated changes in these molecules after the application of continuous positive airway pressure (CPAP), the standard treatment for sleep apnoea.

The study identified a blood profile composed of 33 metabolites, mainly lipids and bile acids, in patients with sleep apnoea compared to patients without sleep apnoea. In addition, a correlation was reported between some of these biomarkers and variables related to the severity of this pathology. Analysis revealed that blood levels of 4 metabolites provided 98% accuracy for the detection of sleep apnoea. However, it is important to note the exploratory nature of this study, which needs to be validated in future research.

CPAP treatment associated with changes in sleep apnoea altered metabolites

Treatment with continuous positive airway pressure was associated with changes in 5 plasma metabolites previously altered by the effects of sleep apnoea.

The Ramón y Cajal researcher at the University of Lleida and CIBERES at IRBLleida, and last signatory of this work, Manuel Sánchez de la Torre, indicates that "analysing these profiles, we found a molecular fingerprint of sleep apnoea, which was modified after effective treatment with CPAP". Therefore, "our results could represent a potential tool that would contribute to the diagnostic process of sleep apnoea, and would allow us to know in greater detail the pathological consequences of this disease".

Article:

Plasma profiling reveals a blood-based metabolic fingerprint of obstructive sleep apnea. Lucía Pinilla, Iván D Benítez, Fernando Santamaría-Martos, Adriano Targa, Anna Moncusí-Moix, Mireia Dalmases, Olga Mínguez, Maria Aguilà, Mariona Jové, Joaquim Sol, Reinald Pamplona, Ferrán Barbé, Manuel Sánchez-de-la-Torre. Biomed Pharmacother. 2022 Jan; 145:112425. doi: 10.1016/j.biopha.2021.112425. Epub 2021 Nov 17. https://pubmed.ncbi.nlm.nih.gov/34800782/