Sleep and Respiration in 100 Healthy Caucasian Sleepers--A Polysomnographic Study According to American Academy of Sleep Medicine Standards

Abstract

Study objectives: Despite differences between American Academy of Sleep Medicine (AASM) and Rechtschaffen and Kales scoring criteria, normative values following the current AASM criteria are lacking. We investigated sleep and respiratory variables in healthy adults over the lifespan, and established polysomnographic normative values according to current standards.

Design: Prospective polysomnographic investigation.

Setting: Academic referral hospital sleep laboratory.

Participants: One hundred healthy sleepers aged 19-77 y were selected from a representative population sample by a two-step screening.

Interventions: N/A.

Measurements and results: All subjects underwent one full-night polysomnography. Sleep and arousals were scored according to AASM standards. Respiration was scored according to AASM 2007 and 2012 criteria in order to compare both methods. Percentile curves showed age-related differences in sleep architecture: a decrease was found for sleep efficiency [≤ 30 y: 87.0 (71.9-94.1)% versus > 60 y: 79.7 (44.5-90.9)%], total sleep time [≤ 30 y: 413.5 (345.6-451.9) min versus > 60 y: 378.3 (216.0-440.0) min], the percentages of N3 [≤ 30 y 20.7 (15.2-37.5)% versus > 60 y: 14.9 (2.4-35.6)%] and rapid eye movement sleep [≤ 30 y 15.5 (7.5-23.6)% versus. > 60 y: 10.3 (1.9-21.9)%], whereas the percentage of wake time after sleep onset increased with age [≤ 30 y 6.0 (1.9-22.8)% versus > 60 y: 15.2 (6.3-48.7)%]. The apnea-hypopnea index (AHI) was higher when applying the AASM 2012 criteria [AHI AASM 2007 0.7 (0.0-21.5)/h versus 2012: 1.7 (0.0-25)/h; P < 0.001]. Eight percent of subjects had an AHI > 15/h.

Conclusions: This study provides normative data on sleep macrostructure, microstructure, and respiration in adults following AASM standards. Furthermore, we demonstrated that respiration scoring according to AASM 2012 results in higher AHIs, and challenge the use of age-independent respiratory cutoff values.

Keywords: gender; normative; polysomnography; sleep architecture; sleep disordered breathing.