Cardiovascular and Somatic Comorbidities and Sleep Measures Using Three Hypopnea Criteria in Mild Obstructive Sleep-Disordered Breathing: Sex, Age and Body Mass Index Differences in a Retrospective Sleep Clinic Cohort

Author Department

Neurology; Healthcare Quality; Medicine

Document Type

Article, Peer-reviewed

Publication Date



Study objectives: To describe sex, age and body mass index (BMI) differences in comorbidities and polysomnography (PSG) measures, categorized using three different apnea-hypopnea index (AHI) criterion, in sleep clinic patients with mild obstructive sleep-disordered breathing (SDB).

Methods: A retrospective cohort of 305 (64% female) adult sleep clinic patients who underwent full night in-laboratory polysomnography diagnosed with mild SDB and prescribed positive airway pressure (PAP). Effects of sex, age and BMI on comorbidities and PSG measures including rates of AHI defined by ≥3% desaturations (AHI3%), with arousals (AHI3%A), by ≥4% desaturations (AHI4%) and by respiratory disturbance index (RDI) were evaluated.

Results: 69 (23%), 116 (38%), 258 (85%) and 267 (88%) patients had AHI4%, AHI3%, AHI3%A and RDI ≥5, respectively. 90- day PAP adherence rates were 45.9% overall and higher in women > 50 (51.2%, p=0.013)) and men (54.5%, p= 0.024) with no difference whether AHI4% or AHI3%A was <5 or ≥5. Men and women had similar rates of daytime sleepiness (43.3%), anxiety (44.9%) and hypertension (44.9%). 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 had depression, migraines, and anemia and more patients with AHI4% ≥5 had CHF. Women were more likely to have higher sleep maintenance and efficiency, shorter average obstructive apnea and hypopnea durations and less supine-dominant pattern. Average obstructive apnea and hypopnea duration decreased with increasing BMI and average hypopnea duration increased with age. Obstructive apnea duration and obstructive hypopnea with arousal duration decreased with increasing BMI. More women had AHI4% <5 (81.5% vs 69.1%), AHI3% <5 (68.7% v 49.1%), and AHI3%A <5 (18.5% vs 10.0%). Older age and higher BMI were associated with higher AHI.

Conclusions: Current AHI criteria do not predict comorbidities or adherence in mild sleep-disordered breathing patients. In this hypothesis generating descriptive analysis, sex, BMI and age may all be factors that should be accounted for in future research of mild SDB patients. Different sleep study measures may weigh differently into risks of cardiovascular versus somatic comorbidities.