Two new research reports, presented at the American Thoracic Society2007 International Conference, indicate that obstructive sleep apneaups your risk of type 2 diabetes and increases your risk of heartattack.
Apnea means "without breath" in Greek ("A" means "without," as in"asymptomatic," and "pnea" means breath, as in "pneumatic" and"pneumonia.") In obstructive sleep apnea (OSA), the upper airway isobstructed when it narrows or collapses during sleep, so breathingstops temporarily.
Consequently, the sleeper may be aroused up to hundreds of timeseach night, just enough to start breathing again. Usually thesleeper has no recollection of the partial waking episodes, butfeels tired and poorly rested every day.
Often OSA accompanies obesity, perhaps because more tissue developsin the throat and at the back of the mouth. When that tissuecollapses during the relaxation of sleep, less oxygen makes it intothe lungs and bloodstream. This lack of oxygen may trigger thebody's "fight or flight" response, producing high levels of cortisolthat lead to insulin resistance and glucose intolerance.
The first study, from the Yale School of Medicine, examined 593patients who had been referred for evaluation of apnea. Eachpatient underwent an overnight sleep study in a lab and then wasfollowed for up to six years. The researchers found that patientsdiagnosed with OSA had over 2-1/2 times the risk of developing type2 diabetes compared to those without it. The more severe theirapnea, the higher was the risk of diabetes.
The second study evaluated a group of 1,123 patients who underwentthe same type of overnight sleep evaluation and were then followedfor four to five years. The study found that OSA increased aperson's risk of having a heart attack or dying by thirty percentover that period. Again, the more severe the OSA, the greater wasthe risk.
It is recommended that people who have symptoms of OSA, includingloud snoring and day-time sleepiness, consult their physician. Themost effective non-surgical treatment for OSA is nasal continuouspositive airway pressure (CPAP); it involves wearing a mask over thenose that forces air into the airway during sleep, therebypreventing the airway from closing. Previous research has indicatedthat use of CPAP may reduce A1c levels by an average of twelvepercent.
Sources: American Thoracic Society International Conference
For more information on this subject, see "Sleep Apnea", September 2006.