How Sleep Apnea Leads to Heart Disease

Sleep apnea affects more than twelve million Americans, according to the Sleep Apnea Foundation. Researchers from Emory University have discovered how sleep apnea leads to heart disease. The new findings suggest a different approach to treating sleep apnea that targets lowering expression of the enzyme NADPH oxidase in sleep apnea sufferers to decrease risk of heart disease.

Researchers from Emory University identified NADPH and its role in sleep apnea. NADPH enzymes become more prevalent in the presence of sleep apnea, leading to heart disease from thickening of the blood vessels in the lung. The researchers found that mice lacking NADPH were immune to the effects of low oxygen levels (hypoxia) that occurs during sleep apnea.

Senior study author C. Michael Hart, professor of medicine at Emory University School of Medicine and Atlanta Veterans Affairs Medical Center explains,” Anything that blunts sleep apnea’s effects on blood vessel physiology could reduce its impact on (heart) disease risk”.

The new findings also suggests that current treatment for sleep apnea using air pressure delivered by CPAP machines to deliver oxygen during periods of sleep apnea may be harmful. NADPH also plays a role in immunity. People with genetic mutations of NADPH have frequent bacterial infections, leading the scientists to believe an indirect approach to treating sleep apnea would not only prevent heart disease, but also keep immunity intact. NADPH also interferes with nitric oxide production, an important molecule that keeps blood vessels relaxed.

Obstructive sleep apnea is the most common form of intermittent interruption of breathing during sleep. Researchers now show sleep apnea leads to increased production of NADPH enzymes, in turn leading to thickening of the blood vessels in the lungs. Sleep apnea can lead to pulmonary hypertension, a condition that decreases the heart’s ability to pump blood throughout the body, increasing risk for heart disease. The new study shows that sleep apnea leads to heart disease from lower levels of NADPH enzymes that thicken blood vessels.

Woodruff Health Sciences Center