Circadian Rhythm Disturbance in Acute Ischemic Stroke Patients and Its Effect on Prognosis

<b><i>Introduction:</i></b> Poststroke sleep disturbances are common and can affect stroke outcomes, but the clinical studies mainly focus on breathing-related sleep disorders, while the bidirectional impact of circadian rhythm dysfunction in ischemic stroke remains unknown. This study observed the characteristics of melatonin secretion in acute ischemic stroke patients and evaluated whether melatonin rhythm impacts the prognosis after stroke by assessing the neurological function, cognition, emotion, and quality of life 3 months after stroke. <b><i>Methods:</i></b> Acute ischemic stroke patients were selected from the Department of Neurology Inpatients of the Second Hospital affiliated with Soochow University from October 2019 to July 2021. Healthy control subjects were recruited at the same time. Demographic and clinical data were collected, and relevant scale scores (including neurological function, cognition, emotion, and sleep) were assessed within 2 weeks of onset and followed up 3 months later. All participants collected salivary melatonin samples on the 4th day of hospitalization and dim light melatonin onset (DLMO) was calculated according to melatonin concentration. Stroke patients were then divided into three groups based on their DLMO values. <b><i>Results:</i></b> A total of 74 stroke patients and 33 control subjects were included in this analysis. Compared with healthy controls, stroke patients exhibited a delayed melatonin rhythm during the acute phase of stroke (21:36 vs. 20:38, <i>p</i> = 0.004). Stroke patients were then divided into three groups, namely normal (<i>n</i> = 36), delayed (<i>n</i> = 28), or advanced DLMO (<i>n</i> = 10), based on their DLMO values. A χ² test showed that there were significant differences in the rate of poor prognosis (<i>p</i> = 0.011) and depression tendency (<i>p</i> = 0.028) among the three groups. A further pairwise comparison revealed that stroke patients with delayed DLMO were more likely to experience poor short-term outcomes than normal DLMO group (<i>p</i> = 0.003). The average melatonin concentration of stroke patients at 5 time points was significantly lower than that of the control group (3.145 vs. 7.065 pg/mL, <i>p</i> &lt; 0.001). Accordingly, we split stroke patients into three groups, namely low melatonin level (<i>n</i> = 14), normal melatonin level (<i>n</i> = 54), or high melatonin level (<i>n</i> = 6). Unfortunately, there were no great differences in the clinical characteristics, cognition, emotion, sleep quality, and short-term outcome among groups. <b><i>Conclusions:</i></b> This is a preliminary study, and our results indicate that changes in melatonin secretion phase of stroke patients may have effect on their short-term prognosis.