Sleep disorders can have long-lasting effects By Gary Neidrick Sleep disordered breathing includes a group of respiratory ailments characterized by pauses in breathing or the quantity of ventilation during sleep. One of the more common sleep disordered breathing conditions is obstructive sleep apnea (OSA). OSA occurs when there is an absence of airflow to the lungs lasting for longer than 10 seconds during sleep. It results from partial or complete blockage of the upper airway during sleep, and its symptoms include snoring, restless and non-restorative sleep, shortness of breath, headaches and excessive daytime sleepiness. Evidence from studies over the last several years indicates that some of the changes that occur during the night in the sleep apnea sufferer have impact throughout the day. For example, it is thought that OSA may be a contributing factor in some patient’s high blood pressure, and that OSA may worsen the effect of high blood pressure in others. It may also make the hypertension more difficult to successfully control. This becomes of broader concern given recent statistics from Hypertension: Journal of the American Heart Association that approximately 65 million Americans have high blood pressure. From an international perspective, the British medical journal Lancet reports on a study suggesting that more than a quarter of the world’s population is hypertensive. There is also evidence to tie sleep disordered breathing to blood sugar problems. The chronic increase in “fight or flight” chemicals within the body may contribute to insulin resistance, a factor in diabetes mellitus. It has also been suggested that sleep loss, including that related to OSA or other sleep disordered breathing, may be a contributing factor to obesity in some individuals. Thus, while obesity may contribute to OSA, the disorder itself may also perpetuate obesity, owing to chemical imbalances it causes and the lack of energy during waking hours. This “viscous cycle” becomes of particular concern when we consider that overweight problems and obesity are of increasing frequency both in the United States and worldwide. There is also growing evidence that sleep disordered breathing is an independent risk factor for coronary artery disease, the type of heart disease that puts us at risk for a heart attack. Though the two disorders share many risk factors, it is currently felt that sleep disordered breathing may, in itself, contribute to the development or progression of coronary artery disease. Individuals with chronic heart failure may be particularly sensitive to the effects of OSA. The repetitive episodes of “fight or flight” nervous system and chemical responses throughout the night, coupled with dramatic blood pressure changes and drops in blood oxygen levels, can wreak havoc on an already damaged heart. Given the fact that heart failure affects between 5 and 6 million North Americans and is increasing in prevalence, any disorder that may cause or worsen heart failure is worthy of concern and investigation. Sleep disordered breathing in general, and obstructive sleep apnea in particular, can be a significant source of annoyance to both the sufferer and others exposed to its symptoms. Medical science is compiling growing evidence that its effects reach far beyond a restless night and non-restorative sleep. The chemical stresses it causes in the sufferer can dramatically impact both quality of life and life expectancy. Gary Neidrick is the Director of Cardiopulmonary Services at Mount Nittany Medical Center.