This study was done to describe sex, age, and BMI differences in comorbidities and polysomnography measures, categorized using 3 different AHI criteria in sleep clinic patients with mild obstructive sleep-disordered breathing.

23%, 38%, 85%, and 88% patients had AHI4%, AHI3%, AHI3%A, and respiratory disturbance index ≥ 5 events/h, respectively. Ninety-day positive airway pressure adherence rates were 45.9% overall and higher in women > 50-years-old and men with no difference whether AHI4% or AHI3%A was < 5 or ≥ 5 events/h. Men and women had similar rates of daytime sleepiness, anxiety, and hypertension. Women were more likely to have obesity, anemia, asthma, depression, diabetes, fibromyalgia, hypothyroidism, migraine, and lower rates of coronary artery disease. More patients with AHI4% < 5 events/h had depression, migraines, and anemia, and more patients with AHI4% ≥ 5 events/h had congestive heart failure. Women were more likely to have higher sleep maintenance and efficiency, shorter average obstructive apnea and hypopnea duration, and less supine-dominant pattern. Average obstructive apnea and hypopnea duration decreased with increasing BMI, and average hypopnea duration increased with age.

The study concluded that current AHI criteria do not predict comorbidities or adherence in mild sleep-disordered breathing patients. Sex, BMI, and age may all be factors that should be accounted for in future research.