OSA, which is characterized by repeated cessation and commencing of breathing that disrupts sleep, significantly increases the risk of cardiovascular disease and has long been seen mainly as a result of anatomical factors and upper airway obstruction.

But scientists from Wrocław Medical University, working with the Hirszfeld Institute of Immunology and Experimental Therapy of the Polish Academy of Sciences, have shown that the condition also has strong neurobiological and genetic components.

Their findings, published in Annals of Medicine, could open the way to new methods of diagnosing and treating the common sleep disorder.

Professor Mieszko Więckiewicz, Head of the Department of Experimental Dentistry at Wrocław Medical University, said; “Our study is groundbreaking and has been accepted for publication in a prestigious journal. This is the first such comprehensive clinical study to document elevated dopamine levels in obstructive sleep apnoea, as well as the role of a specific gene polymorphism in the potential modulation of disease severity.”

Nearly 300 people took part in the research. Dopamine levels were measured in 153 participants, including 96 OSA patients and 57 healthy volunteers.

In a second phase, involving 286 people, scientists examined genes involved in dopamine metabolism, focusing on three single-nucleotide polymorphisms (SNPs): COMT, which helps break down dopamine, and DRD1 and DRD2, which encode dopamine receptors.

The researchers found significantly higher dopamine levels in people with OSA, particularly men, regardless of other risk factors.

They also identified a genetic link: carriers of a variant of the dopamine receptor gene (DRD2 rs1800497) were more likely to experience more severe symptoms, including more frequent apnoeas, hypopnoeas, and arousals.

“Our findings could change the way doctors and scientists view sleep apnoea. We show that it is not only a problem with airway patency, but also with neurochemistry and genetics. This opens up a potential path to completely new methods of diagnosing and treating this disease,” said Helena Martynowicz, PhD, professor at Wrocław Medical University.

Joanna Smardz, another of the study’s authors, highlighted the diagnostic potential. “In the future, determining blood dopamine levels and analysing selected genes may complement the diagnostic gold standard, polysomnography. Genetic testing, in turn, will allow to identify patients at particular risk of severe disease, enabling faster implementation of therapy and more effective monitoring,” she said.

The researchers believe treatment approaches could also evolve. “Modulating the dopaminergic pathway, for example, using drugs that target the D2 receptor, could become an innovative adjunctive therapy for patients with OSA. The integration of neurobiology, genetics, and clinical practice makes this study an important step towards precision medicine in the treatment of obstructive sleep apnoea. In the future, this could mean better adjusted diagnosis and treatment, and consequently, more effective help for patients and a significant improvement in their quality of life,” Więckiewicz said.

(PAP)

PAP - Science in Poland

ros/ zan/ kap/

tr. RL