RESUMEN
Objective:To investigate the characteristics of the nocturnal melatonin secretion concentration and circadian rhythm in patients with wake-up stroke (WUS).Methods:Patients with acute ischemia stroke (AIS) admitted to the Department of Neurology, the Second Affiliated Hospital of Soochow University from October 2019 to August 2022 were enrolled. They were divided into WUS group and non-WUS group. Saliva samples within one week after admission were collected (at 19∶00, 20∶00, 21∶00, 22∶00, and 23∶00) and melatonin concentration was measured. Melatonin secretion curve graph was drawn, dim light melatonin onset (DLMO) was calculated, and circadian rhythms were evaluated. The differences in endogenous circadian rhythms between the WUS group and the non-WUS group were compared. The relevant factors of WUS were determined by multivariate logistic regression analysis. Results:A total of 116 patients with AIS were included, with 79 males (68.1%), aged 59.9±10.3 years; 35 patients (30.2%) were WUS. Univariate analysis showed that there was a statistically significant difference in the infarct site between the WUS group and the non-WUS group ( P=0.019). At 21:00 ( P=0.004) and the average ( P=0.038) nighttime melatonin concentration in the WUS group were significantly lower than those in the non-WUS group, and DLMO showed a significant delay compared to the non-WUS group (21:28:08 vs. 20:57:57; P=0.015). Multivariate logistic regression analysis showed a significant independent correlation between DLMO delay and WUS (odds ratio 1.792, 95% confidence interval 1.123-2.858; P=0.014). Conclusion:Patients with WUS may have endogenous circadian rhythm delay, which is an independent risk factor for WUS.