Reserves, Injury Severity, and Outcomes in Traumatic Brain Injury: A CENTER-TBI Observational Study.

Stroke, also known as a cerebrovascular accident, is an acute neurological event caused by the sudden interruption of cerebral blood flow, leading to neuronal injury and functional impairment. It remains one of the leading causes of death and long-term disability worldwide, posing a substantial public health burden. According to the Global Burden of Disease Study 2019, stroke accounted for over 12 million new cases, 6.5 million deaths, and more than 143 million disability-adjusted life years globally. In the United States, approximately 800,000 individuals experience a new or recurrent stroke each year, with notable disparities across demographic and socioeconomic groups. Although traditional risk factors such as hypertension, diabetes, and smoking are well established, growing evidence suggests that sleep-related behaviors may also play an important role in cerebrovascular health. In modern societies, chronic sleep deprivation has become increasingly prevalent, with more than one-third of adults reporting insufficient sleep during weekdays. As a compensatory behavior, many individuals engage in weekend catch-up sleep (WCS), defined as extended sleep duration on non-workdays compared with weekdays. Unlike habitual sleep duration, WCS reflects a dynamic pattern of sleep compensation and circadian variability. This pattern may have specific implications for cerebrovascular health. On one hand, moderate WCS may partially counteract the adverse physiological effects of sleep debt by reducing systemic inflammation, improving endothelial function, and restoring autonomic balance and metabolic homeostasis – pathways closely linked to stroke development. On the other hand, excessive or irregular catch-up sleep may indicate circadian misalignment and sleep fragmentation, which have been associated with adverse vascular outcomes, including increased arterial stiffness, impaired glucose metabolism, and elevated blood pressure variability. Together, these findings suggest that the relationship between WCS and cerebrovascular health may be complex and potentially nonlinear. However, the relationship between WCS and stroke has not been well established, and existing evidence remains limited. Most prior studies have focused on overall sleep duration or sleep quality, with relatively little attention to compensatory sleep behaviors such as WCS. Therefore, whether WCS is associated with stroke risk and the potential shape of this association remain unclear.