Abstract
STUDY OBJECTIVES: To describe sex, age, and body mass index (BMI) differences in comorbidities and polysomnography measures, categorized using 3 different apnea-hypopnea index (AHI) criteria in sleep clinic patients with mild obstructive sleep-disordered breathing. METHODS: A retrospective cohort of 305 (64% female) adult sleep clinic patients who underwent full-night in-laboratory polysomnography having been diagnosed with mild sleep-disordered breathing and prescribed positive airway pressure. Effects of sex, age, and BMI on comorbidities and polysomnography measures, including rates of AHI defined by ≥ 3% desaturations (AHI(3%)), with arousals (AHI(3%A)), by ≥ 4% desaturations (AHI(4%)), and by respiratory disturbance index, were evaluated. RESULTS: Sixty-nine (23%), 116 (38%), 258 (85%), and 267 (88%) patients had AHI(4%), AHI(3%), AHI(3%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 (51.2%, P = 0.013) and men (54.5%, P = 0.024) with no difference whether AHI(4%) or AHI(3%A) was < 5 or ≥ 5 events/h. 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 AHI(4%) < 5 events/h had depression, migraines, and anemia, and more patients with AHI(4%) ≥ 5 events/h had congestive heart failure. 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 AHI(4%) < 5 (81.5% vs 69.1%), AHI(3%) < 5 (68.7% vs 49.1%), and AHI(3%A) < 5 events/h (18.5% vs 10.0%). Greater 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 sleep-disordered breathing patients. Different sleep study measures may weigh differently in calculations of risk for cardiovascular versus somatic comorbidities.