Clinical ReviewPrevalence of obstructive sleep apnea in the general population: A systematic review
Introduction
Obstructive sleep apnea (OSA) is a condition characterized by repeated episodes of partial or complete obstruction of the respiratory passages during the sleep [1], [2], [3]. The body's response to obstructed breathing leads to arousal of the brain, sympathetic activation, and oxygen desaturation in the blood (12). Repeated episodes of upper airway obstruction during sleep may result in sleep fragmentation and non-restorative sleep. Those who have OSA may complain of tiredness, excessive day-time sleepiness, insomnia, or morning headaches, but many are asymptomatic ∗[4], ∗[5], [6]. The main metric for diagnosing OSA is the apnea hypopnea index (AHI). This reflects the average number of significant breathing disturbances per hour of sleep and is measured during some form of polysomnography (sleep study). While either laboratory-based, attended polysomnography (i.e., type 1 sleep study) or home based full polysomnography (type 2 sleep study) remains the ‘gold-standard’ of diagnosis, it has been suggested that other simpler diagnostic methods using measures such as nasal airflow, respiratory effort and/or events of oxygen desaturation in blood during sleep (type 3 or 4 sleep studies) also render reasonably accurate diagnostic results [7]. Screening questionnaires are sometimes used to detect those who are at high risk of OSA, who subsequently may undergo sleep studies [8], [9]. OSA is emerging as a major health problem, particularly in high income countries. Its high disease burden is related to both the health care costs attributable to OSA alone and to its contribution as an independent risk factor for cardiovascular, metabolic, and psychiatric disorders such as hypertension, stroke, diabetes, and depression [3], [7] which are global health priorities [10], [11].
Many studies have demonstrated that OSA is a highly prevalent disorder, both in the general population and in specific disease-related and population sub-groups [6], ∗[12], [13], [14], [15], ∗[16]. The reported prevalence of OSA has increased over time, in part due to increasing rates of obesity. Obesity is recognized as a major risk factor for OSA [17], ∗[18] and there has been an enormous increase in rates of obesity throughout the world over the past 25 y [19], [20], [21], [22], [23]. However, some of this increase in prevalence of OSA can be attributed to changes in measurement techniques and definitions for classifying respiratory events (predominantly hypopneas, the partial obstructions to breathing), which have changed over this same period [24], [25]. Current measurement techniques and respiratory scoring rules are more sensitive at detecting respiratory disturbances than older measures and rules ∗[12], ∗[26], leading to higher AHI ∗[4], [27], [28]. Within this changing context, there are no published data available to date that are derived from systematically synthesizing evidence related to the population prevalence of OSA. Accurate determination of population prevalence is essential to estimate the true burden of OSA, which is vital when considering population-based health policies and intervention strategies.
The aim of this systematic review was to determine the prevalence of OSA in adults in the general population. Further aims were to determine how prevalence estimates: a) varied according to measurement criteria used for OSA b) were changing over time with rising obesity and; varied between populations and age- and sex- specific sub-groups.
Section snippets
Methodology
All authors discussed and agreed upon the protocol for the systematic review prior to commencement.
Results
Our systematic search (last run on 3rd March 2016) on PubMed and Embase identified 2318 and 3807 articles, respectively. After removing the duplicates, we screened the title and abstract of the remaining 3560 articles. A total of 59 articles were selected for full paper review, of which 21 articles were found to meet the inclusion criteria (the excluded studies and reasons for their exclusion are shown in Table S2). Searching reference lists of these articles yielded a further three eligible
Discussion
OSA in the general adult population ranged from 9% [46] to 38% [16], and was higher in men compared with women. Prevalence of OSA increased with increasing age. It was also greater in obese men and women compared with overweight men and women. However, diagnostic criteria and the age groups and cut-off levels of the indices used in reporting sleep apnea varied widely between studies. Reported prevalence of OSA/OSAS also varied considerably depending on the diagnostic criteria used and the age
Conclusion
This systematic review has highlighted both the substantial methodological heterogeneity that exists in studies that investigated the population prevalence of OSA, and the resultant wide variation in the reported prevalence: the overall prevalence of any OSA ranged from 9% to 38% in the general adult population, from 13% to 33% in men and from 6% to 19% in women, although much higher in the elderly groups. The available data were primarily limited to Europe and North America. Despite these
Conflicts of interest
Prof Hamilton has received equipment for research from Resmed and Philips Respironics. None of the other authors declared conflicts of interest.
Acknowledgements
No financial or other support was used for conducting this systematic review.
References∗ (76)
- et al.
Updates on definition, consequences, and management of obstructive sleep apnea
Mayo Clin Proc
(2011) - et al.
Prevalence of sleep-disordered breathing in the general population: the HypnoLaus study
Lancet Respir Med
(2015) - et al.
Prevalence of obstructive sleep apnea among patients with coronary artery disease in Saudi Arabia
J Saudi Heart Assoc
(2015) - et al.
Obstructive sleep apnea syndrome in the Sao Paulo epidemiologic sleep study
Sleep Med
(2010) - et al.
The epidemiology of chronic pain in children and adolescents revisited: a systematic review
Pain
(2011) - et al.
The effect of osteoarthritis definition on prevalence and incidence estimates: a systematic review
Osteoarthr Cartil
(2011) - et al.
Prevalence of Barrett's esophagus in Asian countries: a systematic review and meta-analysis
Clin Gastroenterol Hepatol
(2015) - et al.
Characteristics of obstructive and central sleep apnea in the elderly: an interim report
Biol Psychiatry
(1987) - et al.
Prevalence of sleep apnea syndrome among Swedish men – an epidemiological study
J Clin Epidemiol
(1988) - et al.
Prevalence and risk factors of obstructive sleep apnea among middle-aged urban Indians: a community-based study
Sleep Med
(2009)