Chronic intermittent hypobaric hypoxia induces cardiovascular dysfunction in a high-altitude working shift model

Area of Science:

• Cardiovascular Physiology
• Environmental Medicine
• Occupational Health

Background:

• Shift work involving altitude changes, such as mining or astronomy, leads to chronic intermittent hypobaric hypoxia (CIHH).
• The long-term cardiovascular effects of CIHH exposure are not fully understood.
• Understanding CIHH's impact is crucial for workers in relevant industries.

Purpose of the Study:

• To investigate the cardiac and vascular effects of CIHH in adult rats.
• To simulate high-altitude and low-altitude working shifts.
• To characterize structural and functional cardiovascular changes due to CIHH.

Main Methods:

• Echocardiography for in vivo cardiac function assessment.
• Wire myography for ex vivo vascular reactivity.
• Histology and molecular biology techniques for in vitro cardiac morphology and protein analysis.
• Comparison between CIHH-exposed rats and normobaric normoxic controls.

Main Results:

• CIHH induced cardiac dysfunction, including left and right ventricle remodeling and increased collagen in the right ventricle.
• Elevated HIF-1α levels and decreased antioxidant capacity were observed in cardiac tissue.
• CIHH impaired vascular function, reducing nitric oxide-dependent vasodilation in carotid and femoral arteries.

Conclusions:

• CIHH leads to cardiac and vascular dysfunction through ventricular remodeling and impaired vasodilation.
• These findings underscore the cardiovascular risks associated with CIHH.
• Periodic cardiovascular evaluation is recommended for high-altitude workers exposed to CIHH.