Characterization of cyclic alternating pattern during sleep in older men and women using large population studies

Abstract

Study Objectives To assess the microstructural architecture of non-rapid eye movement (NREM) sleep known as cyclic alternating pattern (CAP) in relation to the age, gender, self-reported sleep quality, and the degree of sleep disruption in large community-based cohort studies of older people. Methods We applied a high-performance automated CAP detection system to characterize CAP in 2,811 men from the Osteoporotic Fractures in Men Sleep Study (MrOS) and 426 women from the Study of Osteoporotic Fractures (SOF). CAP was assessed with respect to age and gender and correlated to obstructive apnea–hypopnea index, arousal index (AI-NREM), and periodic limb movements in sleep index. Further, we evaluated CAP across levels of self-reported sleep quality measures using analysis of covariance. Results Age was significantly associated with the number of CAP sequences during NREM sleep (MrOS: p = 0.013, SOF = 0.051). CAP correlated significantly with AI-NREM (MrOS: ρ = 0.30, SOF: ρ = 0.29). CAP rate, especially the A2+A3 index, was inversely related to self-reported quality of sleep, independent of age and sleep disturbance measures. Women experienced significantly fewer A1-phases compared to men, in particular, in slow-wave sleep (N3). Conclusions We demonstrate that automated CAP analysis of large-scale databases can lead to new findings on CAP and its subcomponents. We show that sleep disturbance indices are associated with the CAP rate. Further, the CAP rate is significantly linked to subjectively reported sleep quality, independent from traditionally scored markers of sleep fragmentation. Finally, men and women show differences in the microarchitecture of sleep as identified by CAP, despite similar macro-architecture.

A Systematic Review of Sleep Measurement in Critically Ill Patients

“…For example, there can be significant arousal-related phasic events, even when the macrostructure of sleep appears to be normal (87). Another example, the cyclic alternating pattern (CAP), a periodicity dimension of NREM sleep that involves sleep microstructures such as high amplitude, slow EEG bursts, has been shown to be sensitive for identifying and quantifying sleep disturbances in subjects with decreased sleep quality (88,89). In a well-designed case-control study comparing 78 untreated depressed patients with 18 age and sex-matched controls, there were no major differences in sleep macrostructure variables, but a significantly higher CAP (60% in depressed patients vs. 35% in controls) (90).…”

New and Emerging Approaches to Better Define Sleep Disruption and Its Consequences

“…The cyclic alternating pattern (CAP) is an additional sleep scoring system beyond traditional AASM sleep scoring which aims to quantify NREM discontinuity by characterizing phases of activation (A phases) and periods of inactivity (B phases) (Terzano et al, 2001). Automatic methods of CAP scoring have been proposed (Hartmann and Baumert, 2019) and have been applied to study and define NREM instability in large populationbased studies (Buysse et al, 2010;Hartmann et al, 2020) and may provide unique insight into sleep neurobiology. CAP and its potential utility is discussed in detail in recent comprehensive reviews (Mendonça et al, 2019;Lim et al, 2020).…”

Causality of cortical and cardiovascular activity during cyclic alternating pattern in non-rapid eye movement sleep

“…A larger number of subjects resulting in a greater number of investigated sequences would enable a more comprehensive analysis of the interplay between CNS and ANS during CAP. A possible solution is presented by automated CAP scoring algorithms that are capable of scoring large cohort studies [65][66][67]. Furthermore, the lack of healthy subjects in our analysis and the combination of various sleep pathologies is potentially limiting the significance of the presented results.…”