The prevalence of sleep apnoea

Sleep apnoea is increasing in prevalence, and this trend shows no signs of abating. In a paper published in the Chest Journal, Lawrence et al. wrote, “the demand for sleep medicine services has grown tremendously during the last decade and will likely continue.”

Studies have shown that a substantial proportion of the European and American populations have sleep apnoea. The American Lung Association estimates that about 12 million Americans suffer from obstructive sleep apnea, with the UK Sleep Apnoea Trust estimating 80,000 sufferers in the UK. However, it is worth bearing in mind that these figures may not present an accurate picture, as some researchers claim that, so far, only one in ten patients with the syndrome are being diagnosed and treated.

Forty offices and clinics in the U.S., Germany, and Spain participated in a study to obtain prevalence estimates for key symptoms and features that can indicate the presence of sleep apnoea in a broad range of primary care settings. With a 78% return of 8,000 surveys seeking information on the prevalence of self-reported chronic snoring, sleepiness, obesity, hypertension, and OSA risk calculation, one-third of participants were found to have a high pre-test probability for OSA, with a higher rate in the U.S. (35.8%) than in Europe (26.3%). Sleepiness affected 32.4% in the U.S. versus 11.8% in Europe. Frequent snoring and breathing pauses were similar in both the U.S. and Europe (44%). The paper concluded that “primary care physicians in the United States and Europe will encounter a high demand for services to confirm or manage sleep apnea, sleepiness, and obesity.”

The results from a 2005 poll to determine the prevalence of the symptoms and risk of sleep apnea in the U.S. population, as published in Chest Journal, concluded that based on findings from 1,506 respondents, 57% were at risk from OSA. The paper concluded that “as many as one in four American adults could benefit from evaluation for OSA. Considering the serious adverse health and quality-of-life consequences of OSA, efforts to expedite diagnosis and treatment are indicated.”

Kapsimalis et al. concluded from a study of 1,254 women in the U.S. that “twenty-five percent of the female population was found to be at high risk for OSAS.” Among women at risk, “habitual snoring (61%), observed apneas (7%), and daytime sleepiness (24%) were highly prevalent. Sleep onset insomnia (32%) or maintenance insomnia symptoms (19%) and restless legs syndrome (RLS) symptoms (33%) or body movements (60%) also were frequently reported. The risk increased with age, obesity, and menopause.”

Sleep apnoea is not isolated to developed countries. In a study to determine obstructive sleep apnea among adults in Nigeria, Adewole et al. found that “overall, 19% of participants (22% of men and 16% of women) met the Berlin questionnaire criteria indicating a high risk of OSAS,” and concluded that “OSAS may be more common a medical problem than ever imagined among Nigerians.