Sympathetic activation implicated in sleep disturbance
medwireNews: Individuals reporting disturbed sleep and a history of depressive symptoms have elevated levels of plasminogen activator inhibitor (PAI)-1, reveal findings that indicate a role for sympathetic activation in poor perceived sleep.
PAI-1, a stress-induced acute-phase reactant, has previously been associated with both depressive symptoms and sleep disorders, as well as regular smoking, the metabolic syndrome, and cardiovascular disease, the study researchers report.
They found that levels of the reactant were significantly elevated among 127 individuals with a history of depressive symptoms (Beck Depression Inventory score >9) if they also self-reported moderate-to-severe sleep disturbance on the 15-dimensional questionnaire, compared with slight or no sleep disturbance, at an average of 4.27 µg/mL versus 3.36 µg/mL.
This translated to a 23% increased risk for moderate-to-severe sleep disturbance with every 1-unit increase in PAI-1.
This significantly increased risk was unaffected by factors such as body mass index, age, severity of depression, daily smoking, and use of sleep or lipid-lowering medication.
Lead researcher Antti-Pekka Elomaa (Kuopio University Hospital, Finland) and colleagues, suggest that elevated PAI-1 levels may indirectly disrupt rapid eye movement (REM) and non-REM cycles via sympathetic activation and disrupted suprachiasmatic circadian regulation, thereby contributing to disturbed sleep.
“Previous studies in both healthy and depressed populations have found similar associations between REM sleep patterns and inflammatory markers,” they note in Progress in Neuro-Psychopharmacology & Biological Psychiatry.
As yet, the effects of psychotropic medication on PAI-1 are unknown in the general population, the researchers note, but they add that given the impact of sleep disturbance on individual homeostasis highlighted in their study, this may be a direction for future research.
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By Lucy Piper, Senior medwireNews Reporter