Some researchers estimate that 18 to 25 million people have sleep apnea. Less than a 10 percent are aware of it. More men than women appear to have sleep apnea. Sleep apnea may be under-diagnosed in women. In general, older women have the same incidence as men their own age. A range of studies reports that apnea or hypopnea are present in nine to 24 percent of men and four to 15 percent of women.
Sleep apnea affects people of all ages. Although it is most common in older adults, it has been reported in some 1.6 to 3.4 percent of children. Some experts believe that sleep disorder breathing may occur in as much as 11 percent of children.
Interestingly, one study suggests that although the prevalence of sleep apnea increases with age, its health consequences decline. In the study, apnea was shown to pose more of a threat to a person’s health before age 45 than afterwards. African Americans face a higher risk for sleep apnea than any other ethnic group in the United States. Obesity, and particularly people with fat around the abdomen (the so-called apple shape), is a particular risk factor for sleep apnea, even in adolescents and children. Many people, however, with sleep-disordered breathing, particularly women and small children, are not obese.
Physical Characteristics
Large neck (17" male) (15" female)
Facial characteristics:
- A long lower part of the face
- A narrow upper jaw
- A receding chin
- Overbites
- Larger tongues
- Longer and stiffer soft palates
Characteristics in the throat
- The soft palate (roof of the mouth) and the walls of the throat collapse easily
- The soft palate is stiffer and/or longer than normal
Body position
Often, body position greatly affects the number and severity of episodes of obstructive sleep apnea. At least twice as many apneas occur when a person lies supine (face upward) than when the person lies on their side. This may be due to the effects of gravity, which cause the throat to narrow and the tongue to slide posteriorly (fall back) when a person lies on their back.
Smoking and alcohol use
Smokers are at higher risk for apnea, with heavy smokers (more than two packs a day) having a risk 40 times greater than nonsmokers. Alcohol use has also been associated with apnea, although studies are mixed. One survey reported that 53 percent of people who use alcohol to facilitate sleep, experience symptoms of sleep apnea.
Polycystic ovary syndrome
In one 2000 study, women with polycystic ovary syndrome (PCO) were 30 times more likely than other premenopausal women to have obstructive sleep apnea and excessive daytime sleepiness. PCO is a disorder in which women produce high amounts of androgens (male hormones), particularly testosterone. The elevated levels of male hormones can cause obesity, facial hair and acne. About half of PCO patients also have diabetes. (Obesity and diabetes are both associated with sleep apnea and may be the common factors, although some researchers believe that hormonal imbalances and insulin resistance may actually be causes of apneas.)
A 2001 Swedish study found that people with respiratory tract disorders, including asthma, chronic bronchitis or seasonal allergic rhinitis, reported symptoms of sleep apnea more often than those without any of these ailments.
