Circadian Variations in the Occurrence of Intracerebral Hemorrhage from Different Sources of Income: A Hospital-Based Cross-Sectional Study

Abstract

Background: The onset time of intracerebral hemorrhage (ICH) may be closely related to the working style and living habits of people, which are determined by different income sources in China. Therefore, our purpose was to investigate the Circadian Variations in the occurrence of ICH from different sources of income. Methods: This retrospective study enrolled 4,327 patients with ICH. Based on the time of a day at which the patients developed symptoms, the classifiable onset time was assigned to one of eight three-hour intervals. And based on different income sources, they were categorized into three groups: Farmers, Wage-earners and Freelancers. Characteristics and risk factors of patients were then summarized, and the circadian variation of three groups of patients’ known time of onset and those stratified by gender and age were analyzed.Results: The frequency of ICH onset exhibited significant circadian variation among the three income groups, demonstrating a bimodal distribution in the daytime, with a nadir during the night (all P < 0.001). Three groups showed a significant initial peak between 06:01 and 09:00, with a smaller second peak that between 15:01 and 18:00 for Farmers and Wage-earners and 18:01 and 21:00 for Freelancers. After stratification by gender and age, all demonstrated a bimodal distribution except women in Wage-earners and under 65 years of age in Wage-earners. Conclusions: Different circadian variations of ICH onset time were found in patients with different income sources in southwest China's Chongqing Municipality cohort. Moreover, the frequency and distribution pattern of peak hours were closely related to the working style and living habits of people with different income sources.