TABLE 4.

Prevalence of OSA by body mass index in population-based studies utilizing polysomnography. Reprinted with permission from Young et al. [34]

Study	Number of subjects	Age group (years)	Definition of OSA	BMI (kg/m2)	Prevalence of OSA (percentage)
Pennsylvania, U.S.A. Bixler et al. [22,23]	1,741	20–100	AHI ≥ 15	Women < 32.3 ≥ 32.3 Men < 32.3 ≥ 32.3	Women 1.1 % 7.2% Men 2.0% 13.8 %
Sleep Heart Health, U.S.A. Young et al. [33]	5,615	40–98	AHI ≥ 15	Quartiles 16–24 24–28 28–32 32–59	10 % 13 % 17 % 32 %
Hong Kong, China Ip et al. [25,26]	259	30–60	AHI ≥ 5	Women < 23 ≥ 23 Men < 23 ≥ 23	Women 0.9 % 14.5 % Men 0.9 % 8.8 %

OSA: obstructive sleep apnea; BMI: body mass index