Relationship between Circadian Variation in Ictus of Aneurysmal Subarachnoid Hemorrhage and Physical Activity

Abstract

Objective The circadian pattern of the onset time of aneurysmal subarachnoid hemorrhage (aSAH) has been reported by various authors. However, the effect of the degree of physical exertion on the circadian pattern has not been studied in detail. Therefore, we conducted this study to investigate the effect of physical exertion on the circadian pattern of aSAH. Methods Of the 335 patients presenting with aSAH from January 2012 to December 2017, 234 patients with identifiable onset time and metabolic equivalent (MET) values were enrolled. The onset time of aSAH was divided into 4-hour intervals. The patient’s physical exertion was then assessed on a scale between 1 and 8 METs using generally accepted MET values, and categorized into two groups—light exertion (1 to 4 METs) and moderate to heavy exertion (5 to 8 METs)—to determine the effect of the degree of physical exertion on the onset time distribution of aSAH. Multivariate analysis was used to calculate the odds ratio (OR) between the two groups to determine the effect of the degree of physical exertion on each set of time periods. Results There was a definite bimodal onset pattern that peaked at 08:00–12:00 hours followed by 16:00–20:00 hours ( p <0.001). MET values at all time intervals were found to be significantly higher than the night time (00:00–04:00 hours) values ( p <0.031). The MET value distribution showed a unimodal pattern that slightly differed from the bimodal distribution of the onset time of aSAH. There were no significant differences in the ORs of each time interval according to the degree of the MET value. Conclusion This study reaffirmed that aSAH occurs in a bimodal pattern, especially showing the highest prevalence in the morning. Although aSAH could be related to daily activity, there were no significant changes in diurnal variations affected by the degree of physical exertion.

Chronobiological Patterns of Aneurysmal Subarachnoid Hemorrhage in Central China

“…In this study, we identified a bimodal circadian pattern (morning peak and late afternoon peak) of aSAH onset among the Chinese population by using a nonlinear Fourier model and also performed detailed subgroup analyses to assess potential influencing factors. Some Asian studies reported similar bimodal pattern [ 3 10 36 ]. The difference in chronobiological patterns between Asians and Europeans may due to diverse social habits and dietary patterns in different cultures.…”

“…Previous studies of different races yielded inconsistent results on the diurnal variation of aSAH [ 3 5 6 ]. Most of them were conducted in Western countries, and they lacked subgroup analyses of influencing factors such as age, gender, and hypertension [ 5 6 7 8 9 10 11 ]. The incidence of aSAH onset could be very different among people in distinct cultures for differential lifestyle habits.…”

Potential triggering factors associated with aneurysmal subarachnoid hemorrhage: A large single‐center retrospective study

“…The most frequent time frame for aneurysm rupture is from 7:00 to 12:00, especially for male patients. Aneurysm ruptures often occur in the early morning and early evening, previous studies have reported the same phenomenon 16,26–28 . The potential reason for this phenomenon may be the fluctuation of systemic blood pressure.…”

“…Aneurysm ruptures often occur in the early morning and early evening, previous studies have reported the same phenomenon. 16,[26][27][28] The potential reason for this phenomenon may be the fluctuation of systemic blood pressure. It is well known that the systemic blood pressure starts to increase at 05:00-06:00 and reaches the climax at 09:00, then declines gradually at 18:00 toward a minimum at 02:00-03:00.…”

Risk factors and treatment approach for subarachnoid hemorrhage in a patient with nine intracranial aneurysms

“…Smoking is connected to a transient increase of the blood pressure for a few hours and it could play an important role in the rupture of an aneurysm. A bimodal pattern of SAH occurs in the morning and the evening [10] when cigarette smoking and alcohol use usually displays its peaks.…”