The Impact of Sleep Breathing on 'Vascular Function'—An Initial Report Organized from the Perspective of Internal Environment

■ Sleep is the 'Time Zone Where Vascular Function Changes the Most'

Blood vessels are the 'life-support infrastructure' that delivers oxygen and nutrients to all cells in the body. It has become clear that their function is heavily influenced not only by age but also by changes in the internal environment during sleep. During sleep, muscle tension decreases and posture becomes fixed, leading to patterns in breathing depth, speed, expiration time, and thoracic movement that differ from those during the day. These changes are thought to affect microcirculation (capillaries) and vascular endothelial reactivity.

■ Vessels May Not Only 'Decline' But Also 'Repair'

Recent research suggests that blood vessels do not just decline with age but have the potential for 'autonomous repair and regeneration' when the internal environment is stabilized. However, it is not yet fully understood how this repair process relates to sleep breathing quality.

■ Toratani Visualizes 'Sleep Breathing and Vascular Function'

Toratani Co., Ltd. (Kahoku, Ishikawa Prefecture) is conducting a measurement project on general monitors to visualize the relationship between 'sleep breathing' and 'vascular function.' Currently in the second phase, the project simultaneously captures breathing depth, speed, expiration time, and thoracic movement to analyze their relation to the internal environment. This release reports on the latest visualization data and initial analysis results regarding the relationship between sleep-time internal environment and vascular status.

■ Breathing is a 'Physiological Switch to Adjust Internal Environment'

Breathing quality, especially prolonged expiration, stimulates the parasympathetic nervous system (vagus nerve) through the diaphragm, creating conditions where the internal environment easily stabilizes. Quality refers to comprehensive functions such as depth, stability, and the balance between expiration and inspiration.

■ Vascular Aging as a 'Physiological Result' of 'Declining Breathing Quality'

Continued 'disturbances in internal environment'—such as stress, shallow breathing, sleep deprivation, inflammation, and blood sugar imbalances—damages vascular endothelium and reduces elasticity. When repair cannot keep up, lipids and inflammatory cells accumulate, forming plaques (sludge-like lumps in vessels).

■ 'NO (Nitric Oxide)': The Central Substance for Vascular Rejuvenation

NO, the subject of the 1998 Nobel Prize in Physiology or Medicine, is a 'vascular rejuvenation substance.' It works to soften vessels and prevent thrombi. A fact many do not know: NO is produced in the paranasal sinuses; it is not synthesized unless nasal breathing occurs.

■ Nasal Breathing is the 'Switch for Vascular Rejuvenation', Mouth Breathing is the 'Switch for Vascular Aging'

Since the jaw tends to drop and mouth breathing easily occurs during sleep, maintaining nasal breathing is key to vascular expansion and improved oxygen exchange efficiency. Multiple clinical studies have reported that when microcirculation recovers, oxygen reaches deep inside plaques, inflammation subsides, and consequently, plaques shrink (regression).