Men's Health

Sleeping with the enemy
Restful sleep may not be the only thing that men with sleeping disorders stand to lose. By Awi Curameng, M.D.

The pop culture image of the heavyset male sleeping soundly and snoring away may be comical, but it is certainly not as innocuous as it seems. For starters, the impression of "sleeping soundly" is a misconception.

"Snoring does not always indicate deep, restful sleep," says sleep medicine specialist Dr. Michael Sarte, head of the Center for Snoring and Sleep Disorders of the Medical City General Hospital in Manila. "Snoring may actually disrupt normal sleep patterns, making sleep less restful and leading to daytime drowsiness."

THREAT TO HEALTH
Snoring is, in fact, now identified as part of a cluster of illnesses called sleep-related breathing disorders (SRBDs) or sleep-disordered breathing. In turn, these form part of a larger group of diseases affecting normal sleep called, quite appropriately, sleep disorders. Sleep problems are some of the most common complaints encountered by physicians: recent surveys in the U.S. estimate that as many as one-third of all Americans have a sleep disorder at some point in their lives, and approximately 20 percent to 40 percent of adults report difficulty sleeping at some point each year. Surprisingly, however, the same studies note that many of these disorders remain largely undiagnosed and, consequently, are not treated properly.

"Sleep disorders are important to recognize because they lead to poor health and a diminished quality of life," says Dr. Kristin Corvera, an internist. Everyone experiences the occasional sleepless night due to stress over work or excitement over recent events and this is relatively harmless, she says. Longer-term sleep disturbances, on the other hand, can lead to serious impairments in daytime functioning, driving and industrial accidents, cardiovascular dysfunction and even death. In a review for the online journal Medscape, Dr. Karl Doghramji describes how excessive daytime sleepiness has been implicated in many major catastrophes, including the Three Mile Island Meltdown in 1979, the erroneous launch of the space shuttle Challenger in 1986 and the grounding of the Exxon Valdez in 1989.

The normal 7- or 8-hour long adult sleep episode displays a fairly consistent structure from night to night, made up of alternating periods of rapid eye movement (REM) sleep and non-REM (NREM) sleep. NREM sleep is further subdivided into four stages, with stages 3 and 4 signifying the deepest sleep. "The issue with sleep disorders like SRBDs is how they disrupt this normal sleep architecture," Corvera says. "The brain does not perceive sleep as restful, and daytime sleepiness results."

TYPICALLY MALE
The various forms of insomnia are the most common disorders that are encountered in sleep medicine practice, and these occur more frequently in women than in men, in a ratio of 3:2. In contrast, the majority of patients with sleep-related breathing disorders are male.

"The typical SRBD patient is an obese, hypertensive, middle-aged male," says Sarte. In clinic-based studies, the male-to-female incidence ratio is 10 to 90:1. Results of the Wisconsin Sleep Cohort Study estimate that 4 percent of all men and 2 percent of women have some degree of sleep-disordered breathing. The risk in females has been shown to increase with obesity and after menopause, wherein it may be seen with the same frequency as in males. This strongly implies that the sex hormones estrogen and progesterone influence breathing during sleep, he says, though the mechanism by which this happens is still unclear. In the same manner, there have been reports of men developing SRBD during testosterone replacement therapy.

Some authorities attribute the greater number of sleep-disordered breathing cases in males to the higher incidence of obesity in this population. "Snoring occurs when there is an obstruction to the free flow of air through the passages at the back of the nose and mouth," says Sarte. "During sleep, these soft structures partially collapse because they lose muscle tone, and the noise made as air goes through this narrowed passageway is what we hear as snoring." The substantial fatty tissue often found in the necks of obese individuals contributes greatly to this narrowing.

WAKE-UP CALL
Snoring should never be ignored and instead should be referred to a physician because it may be a warning sign of a condition called obstructive sleep apnea, or OSA. Sarte estimates that one-third of all snorers actually have OSA. "The pathology of OSA is that there are episodes of actual cessation of airflow in the nose and mouth during sleep lasting 10 seconds or longer," he says. "There is complete obstruction of the upper airways even as the patient's lungs are attempting to expand and breathe regularly." The lack of adequate oxygen levels leads to snorting and gasping for breath, and these efforts at breathing normally result in frequent sleep arousals. "Some patients with severe OSA can have hundreds of such awakenings throughout the night," Sarte discloses.

This severe shortage of restful sleep takes its toll on the OSA patient during his waking hours in the form of excessive sleepiness. Daytime functioning is compromised and work productivity decreases as a consequence of poor concentration, short attention span, memory loss, intellectual impairment, personality changes and overwhelming fatigue. "Those who have had to do an all-nighter at the office to finish a big project know how terrible a lack of sleep can feel in the morning," says Corvera. "Basically, you're a zombie the next day. Now imagine how this chronic lack of sleep affects people who have sleep apnea, or any other sleep disorder."

Even more worrisome is new evidence that points to a strong association between SRBDs and the development of hypertension and other cardiovascular problems. "During normal sleep, there is a progressive decrease in heart rate and blood pressure as the heart and blood vessels wind down their activity for the night, so to speak," explains Corvera. In OSA, low oxygen levels, combined with the strong negative pressures created inside the chest as the lungs try to breathe past an almost-closed upper airway, cause the heart to beat faster and the blood vessels to work harder.

"More than 50 percent of OSA patients have hypertension," warns Sarte. Conversely, it has been found that as many as 30 percent of hypertensives have OSA. Sarte says that the latest research has concluded that the blood pressure levels of hypertensives are directly related to the severity of their OSA: the more severe the sleep apnea, the higher an individual's blood pressure is. The presence of OSA, or even snoring, has also been demonstrated to be a significant risk factor for the development of coronary artery disease and stroke. The findings of the Stroke Data Bank at the St. Luke's Medical Center have shown that as many as 75 percent of stroke patients are snorers.

TREATMENT OPTIONS
Individuals suspected of having sleep apnea or other sleeping disorders are made to undergo a test called polysomnography. In a controlled environment (as in a sleep laboratory) at night, the sleeping patient is observed for disturbances in sleep pattern and behavior. Electrical impulses from his brain, eyelids and cheek muscles are recorded to help discriminate between any disruptions in REM and NREM sleep. The presence and rate of airflow in his nose and mouth are likewise measured to help detect any cessations that are diagnostic for OSA. Lastly, an audio-video recording of his sleep episode is made to detect abnormal motor activities, snoring and dysfunctional breathing patterns.

Is sleep-disordered breathing treatable? Most definitely, asserts Sarte. A majority of OSA patients have shown remarkable recovery with continuous positive airway pressure (CPAP). "This is a method whereby positive air pressure is delivered via face mask to keep a patient's upper airways [open] while asleep," he explains. This eliminates snoring, and allows the individual to enjoy more restful sleep. In a recent study, hypertensive OSA patients put on CPAP were shown to have improved blood pressure as early as 3 days after commencement of treatment.