Obstructive sleep apnea (OSA) has been increasingly recognized as a common and serious health condition. OSA can result in cardiovascular, as well as psychological and learning, impacts. These are attributed to intermittent hypoxia, the term for the intermittent deprivation of oxygen experienced by people with OSA.

According to the lead author of a new study, the drop in oxygen levels and inflammation associated with obstructive sleep apnea, over time, can lead to the death of brain cells. This “oxidative stress” causes architectural changes in the brain tissue related to learning and memory. The results of the study indicate that drinking 6 to 10 cups of green team can help offset that decline.

Dr. David Gozal, of the University of Louisville, and team of researchers studied the effects of green tea polyphenols (GTP), added to drinking water, on rats who were intermittently deprived of oxygen similar to the intermittent hypoxia (IH) effects of OSA on humans.

This study included 106 male rats that underwent intermittent oxygen depletion during a 12 hour night cycle for 14 days. Half of these were given the water treated with GTP, the other half were given plain drinking water.

The rats were then tested for markers of oxidative stress and inflammation, in addition to performance in learning and memory tasks.

The rats that were given the GTP water performed significantly better in the tests that those that received plain water. Also, the GTP supplemented rats showed 40% lower levels of markers of oxidative stress.

The antioxidants in green tea have been documented have been shown to improve many conditions, ranging from heart disease and high cholesterol to Alzheimer’s.

The study was published in the Journal of Respiratory and Critical Care Medicine.

Bookmark It

Hide Sites

The results of a Swedish study indicate the obstructive sleep apnea (OSA) is related to decreased insulin sensitivity. Impaired sensitivity for insulin is a known risk factor for diabetes.
Jenny Theorell-Haglöw of the Uppsala University Dept of Medical Sciences, Respiratory Medicine and Allergology, and her team performed the study of 400 healthy women to determine the presence of sleep apnea and its relationship with impaired insulin sensitivity.

Theorell-Haglöw’s team found that, after drinking a standardized glucose solution, levels of both insulin and glucose increased more in the women with sleep apnea compared with women without sleep apnea.

In addition, the insulin and glucose levels remained elevated for a longer time in the women with sleep apnea compared with women without. Moreover, as the severity of the women’s sleep apnea increased the insulin sensitivity decreased. Both sleep apnea and diabetes are prevalent in the general population, and both are closely related to obesity. However, according to the research team, patients with sleep apnea had higher glucose and insulin levels even when obesity was taken into account.

They also found that different variables associated with sleep apnea are related to the impairment of insulin sensitivity, particularly nocturnal hypoxemia.

In their conclusion, the authors state that that sleep apnea affects both insulin and glucose levels and is linked with a decrease in insulin sensitivity in women.

They add: “Decreased insulin sensitivity should be considered when treating patients with OSA.” Their findings were published in the European Respiratory Journal

Bookmark It

Hide Sites

Awareness is increasing about the dangers of sleep apnea. Risk of stroke and cardiovascular events are a couple of the serious impacts of this condition. But what about the impacts of apnea on a patient undergoing surgery for an unrelated condition?

A recent article in US News & World Report highlights the surgery-related risks of sleep apnea. The article is based on an interview with Dr. Frances Chung, professor at the University of Toronto’s University Health Network.

According to Dr. Chung, surgical patients with obstructive sleep apnea are more difficult to manage in terms of anesthesia. Those with apnea have a greater chance of problems such as postoperative complications, difficult intubation, admission to the intensive care unit, and a longer hospital stay. During the surgery the anesthesiologist is present to monitor breathing but afterwards the patient is alone with medical staff occasionally checking on them. It is during this time where the highest level of danger exists.

Most hospitals do not routinely screen for sleep apnea prior to surgery so it is important to consult with your surgeon if you know you have apnea. If you have a CPAP machine, the anesthesiologist will usually put you back on the CPAP after surgery.

Dr. Chung has developed the STOP tool which consists of a series of yes or no questions to screen for sleep apnea. The questions are:

S: Do you snore loudly?

T: Do you often feel tired, fatigued or sleepy during the daytime?

O: Has anyone observed you stop breathing during sleep?

P: Do you have or are you being treated for high blood pressure?

Bookmark It

Hide Sites

Researchers at the Mayo Clinic in Rochester, Minnesota have determined that people with obstructive sleep apnea, the most common form of sleep-disordered breathing (SDB), are far more likely to die suddenly in their sleep from heart related problems than the general population. They also found that this is the opposite of the general population who are more likely to die from heart-related problems, such as heart attack and cardiac arrest, during the day.

It is generally believed that the risk of sudden cardiac death is lower during sleep periods because of the reduction of stress factors that can trigger heart problems. Based on earlier studies, the likelihood of suddenly dying from cardiac arrest or heart attack is actually the highest between the hours of 6 a.m. and noon.

There are several different forms of SBD, however, this study focused only on people that have obstructive sleep apnea. Estimates range upwards of 25% of North Americans who suffer from obstructive sleep apnea.

The data utilized for this study came from the death certificates of 112 Minnesotans who were tested for sleep apnea and subsequently died suddenly from cardiac causes between July 1987 and July 1983. Of the people who died from cardiac causes between midnight and 6 a.m., 46% were diagnosed with obstructive sleep apnea while only 21% had other diagnoses. This is compared to 16% of the general population who die from cardiac causes during those hours.

The study was published in the New England Journal of Medicine.

Bookmark It