Work

Human circadian system causes a morning peak in prothrombotic plasminogen activator inhibitor-1 (PAI-1) independent of the sleep/wake cycle

Year: 2013

Type: article

Abstract: Serious adverse cardiovascular events peak in the morning, possibly related to increased thrombosis in critical vessels. Plasminogen activator inhibitor-1 (PAI-1), which inhibits fibrinolysis, is a key circulating prothrombotic factor that rises in the morning in humans. We tested whether this morning peak in PAI-1 is caused by the internal circadian system or by behaviors that typically occur in the morning, such as altered posture and physical activity. Twelve healthy adults underwent a 2-week protocol that enabled the distinction of endogenous circadian effects from behavioral and environmental effects. The results demonstrated a robust circadian rhythm in circulating PAI-1 with a peak corresponding to ∼6:30 am. This rhythm in PAI-1 was 8-times larger than changes in PAI-1 induced by standardized behavioral stressors, including head-up tilt and 15-minute cycle exercise. If this large endogenous morning peak in PAI-1 persists in vulnerable individuals, it could help explain the morning peak in adverse cardiovascular events.

Source: Blood

DOI: 10.1182/blood-2013-07-517060

Authors: Frank A. J. L. Scheer, Steven A. Shea

Institutions: Brigham and Women's Hospital, Harvard University, Oregon Health & Science University

Language: English

Topic: Blood Coagulation and Thrombosis Mechanisms

Subfield: Hematology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: green

Funders: National Heart, Lung, and Blood Institute, National Center for Research Resources