Relationship between Sleep Quality and Fatigue: Intriguing Discovery by LSMU Researchers

A recent study carried out by researchers at the Lithuanian University of Health Sciences (LSMU) has provided new insights into the link between sleep and fatigue in individuals with anxiety or mood disorders.

A team of researchers from the Laboratory of Behavioural Medicine at the Neuroscience Institute, LSMU MA, Agnė Stanytė, Aurelija Podlipskytė, Audrius Alonderis, Julius Burkauskas, and Vesta Steiblienė, together with co-author Jūrate Macijauskienė, conducted a study to investigate the association of fatigue with objective sleep variables and subjective sleep quality in individuals with anxiety or mood disorders.

The study involved 233 individuals with anxiety or mood disorders. Participants completed self-report questionnaires and took part in an exercise capacity workload test, and polysomnography, a night-time sleep study.

Certain sleep disorders – in particular breathing problems during night-time sleep, periodic limb movement disorder (PLMD) and some other sleep disorders – can only be diagnosed by polysomnography.

Breathing disorders during night-time sleep are viewed a risk factor for both ischaemic heart and brain disease. Therefore, the timely diagnosis of these disorders and appropriate treatment are essential for the prevention of myocardial infarction and stroke, and for the correction of high blood pressure.

Often, breathing problems during sleep can greatly diminish the quality of sleep, resulting in significant daytime drowsiness. This can also elevate the risk of workplace accidents and accidents while driving This kind of research is carried out using an advanced polysomnography system not only at major Lithuanian hospitals, but also at the Palanga Clinic of the LSMU Neuroscience Institute.

The findings indicated that individuals with anxiety or mood disorders who exhibited better objective measures of sleep, such as faster falling asleep, fewer awakenings during the night, and faster REM (Rapid Eye Movement) latency during sleep, demonstrated greater exercise capacity. However, this was not linked to the individuals’ subjective perception of fatigue. The study also showed that individuals who subjectively self-reported their sleep quality as poor also experienced higher levels of subjective mental fatigue.

According to Agnė Stanytė, a researcher at the Behavioural Medicine Laboratory at the Neuroscience Institute, LSMU MA, subjective mental fatigue may not be a consequence of altered sleep architecture, but rather a function of personal judgement of the quality of own sleep.

“Individuals with anxiety or mood disorders often complain of feeling tired, which they attribute to sleep disturbances. Our study shows that objective sleep measures were not related to subjective fatigue, and that mental fatigue was mainly influenced by the subjectively perceived sleep quality,” noted Stanytė.

Although a connection between fatigue and sleep quality has already been demonstrated, previous studies have relied on subjective self-report questionnaires. The study carried out by researchers from the Laboratory of Behavioural Medicine at the Neuroscience Institute, LSMU MA, is therefore one of the first to look at objective and subjective characteristics of fatigue and sleep in individuals with anxiety and mood disorders.

Further investigation is needed to validate the links, but the study by a team of researchers from the Laboratory of Behavioural Medicine at the Neuroscience Institute, LSMU MA, has already received international recognition and interest, with the results published in the scientific journal Physiology & Behaviour. The full article can be accessed here.

Future research efforts are anticipated to to look in more detail at the onset and manifestation of fatigue in individuals with anxiety or mood disorders, aiming to identify effective strategies for managing and mitigating this symptom.