Statins or cholesterol-lowering drugs are often prescribed to fight heart disease. A new study found that they can also help slash a certain cardiovascular risk associated with sleep apnea.
A team of researchers from Columbia University Medical Center detected some of the mechanisms that may raise heart disease risk in sleep apnea patients, as well as the potential role of statins — currently taken by millions of Americans — in helping reverse the process.
The research was published Jan. 6 in the journal Science Translational Medicine.
Sleep Apnea-Heart Disease Link
Affecting over 18 million U.S. adults, sleep apnea occurs when relaxing muscles in the throat during sleep leads to frequent breathing interruptions. This not only disrupts rest but also results in oxygen fluctuations, which in turn causes excess daytime sleepiness and concentration problems.
Sleep apnea has been discovered to triple heart disease, hypertension, and ischemic stroke risks.
The team of Dr. Sanja Jelic, associate professor of medicine, investigated sleep apnea as an independent heart disease risk factor because it was unclear how it exactly leads to the disease.
The study recruited 128 individuals involved at the Sleep Disorders Center of CUMC, including 76 diagnosed with obstructive sleep apnea. The team analyzed cells lining their blood vessel walls, or those particularly extracted from their arm veins.
Keeping CD59 Protein On Cell Surface
In the study, sleep apnea patients had higher levels of CD59, a protein inhibiting the buildup of inflammatory proteins on the surfaces of cells. The protein, however, was detected mainly in the cells instead of on the cell surface, leading to more inflammatory protein deposits.
Involved here is the frequently interrupted oxygen flow in sleep apnea. "[It] draws CD59 away from the cell surface, where it is better positioned to do its job in protecting cells from inflammation," said Dr. Jelic in a press release.
In a portion of sleep apnea patients treated with statins, the team noted that CD59 was preserved on the cell surface, where it should rightfully be and similar to subjects who did not have the sleep condition.
Cholesterol also drew CD59 away from the cell surface through endocytosis.
"We were surprised to discover that these commonly prescribed drugs appeared to reverse the process that leads to vascular injury, and ultimately heart disease, in people with sleep apnea," said Dr. Jelic, who added that statins may be positioned as a primary preventive measure to reduce heart disease risk in this patient group.
The researchers will conduct clinical trials based on the results.
Further Research Needed
Some experts, however, said the findings were limited to the laboratory and warned that sleep apnea patients should not grab a statin prescription just yet.
"This is basic science research, not a clinical study," argued Texas-based cardiologist Dr. Sarah Samaan, saying the degree at which statins reduces heart risk in sleep apnea patients, without other risk factors, remains unknown.
"But it does provide a great launching point for new patient-centered studies on the topic," she added.
Dr. Samaan also said that while these cholesterol drugs do not treat the condition directly, they may assist in lowering the heart-related risks of sleep apnea.
Sleep apnea is treated through natural means such as weight loss and implementing a healthy lifestyle, as well as continuous positive airway pressure (CPAP) delivered via a mask worn during nighttime.
Statins, on the other hand, have been documented to cause a number of side effects, including muscle ache, liver issues, and muscle deterioration from kidney failure.
Lately, the U.S. Preventive Services Task Force (USPSTF) released new draft recommendations backing low to moderate doses of statins prevent first-time heart attack or stroke in high-risk adults.
Photo: David Goehring | Flickr