The association between obstructive sleep apnea and sleep spindles in middle-aged and older men: a community-based cohort study

Abstract

Study objectives Sleep spindles show morphological changes in obstructive sleep apnea (OSA). However, previous small studies have limited generalisability, leaving associations between OSA severity measures and spindle metrics uncertain. This study examined cross-sectional associations between OSA severity measures and spindle metrics among a large population-based sample of men. Methods Community-dwelling men with no previous OSA diagnosis underwent home-based polysomnography. All-night EEG (F4-M1) recordings were processed for artefacts and spindle events identified using previously validated algorithms. Spindle metrics of interest included frequency (Hz), amplitude (µV 2), overall density (11–16 Hz), slow density (11–13 Hz), and fast density (13–16 Hz) (number/minute). Multivariable linear regression models controlling for demographic, biomedical, and behavioural confounders were used to examine cross-sectional associations between OSA severity measures and spindle metrics. Results In adjusted analyses, higher apnea-hypopnea index (AHI/h, as a continuous variable) and percentage total sleep time with oxygen saturation <90% (TST90) were associated with decreased slow spindle density (AHI, B= -0.003, p=0.032; TST90, B= -0.004, p=0.047) but increased frequency (AHI, B=0.002, p=0.009; TST90, B=0.002, p=0.043). Higher TST90 was also associated with greater spindle amplitude (N2 sleep, B=0.04, p=0.011; N3 sleep, B=0.11, p<0.001). Furthermore, higher arousal index was associated with greater spindle amplitude during N2 sleep (B=0.31, p<0.001) but decreased overall density (B= -1.27, p=0.030) and fast density (B= -4.36, p=0.028) during N3 sleep. Conclusions Among this large population-based sample of men, OSA severity measures were independently associated with spindle abnormalities. Further population studies are needed to determine associations between spindle metrics and functional outcomes.

Associations of baseline obstructive sleep apnea and sleep macroarchitecture with cognitive function after 8 years in middle‐aged and older men from a community‐based cohort study

“…As described previously (Parker et al, 2022; Parker, Appleton, et al, 2021; Parker, Melaku, et al, 2021), participants underwent home‐based eight‐channel ambulatory PSG (Embletta X100, Embla Systems, Broomfield, Colorado, USA), which recorded electrical brain activity (electroencephalography [EEG], F4‐M1) and left electro‐oculography with 12‐bit signal resolution, 200 Hz sampling rate, and band‐pass filters (0.3–35 Hz) together with submental electromyography, nasal cannula pressure, thoracic and abdominal motion, finger pulse oximetry, and body position. Trained staff set‐up and attached the PSG equipment and obtained anthropometric measures (height, weight, and body mass index [BMI, kg/m 2 ]).…”

“…Three standardised, validated, and well‐established cognitive tests, described previously (Parker et al, 2022; Parker, Appleton, et al, 2021; Parker, Melaku, et al, 2021), were administered during the 2007–2010 follow‐up and repeated at the 2018–2019 follow‐up examination, including TMT‐A and ‐B and the 30‐point MMSE.…”

Sleep Spindle Characteristics and Relationship with Memory Ability in Patients with Obstructive Sleep Apnea-Hypopnea Syndrome

“…However, previous studies on patients with OSAS mainly focus on the changes in oscillatory neural activity in a single brain region or a single frequency band without considering the synchronization between different brain regions [ 13 , 22 ]. Previous studies have also investigated the relationship between spindle parameters and memory ability [ 23 ]. These studies focused on time domain characteristics such as number, density and frequency, which could not fully reflect the physiological characteristics of the sleep spindle.…”

Association Between Sleep Microstructure and Incident Hypertension in a Population‐Based Sample: The HypnoLaus Study

“…Several studies suggest that quantitative EEG may provide more sensitive markers for identifying patient phenotypes at risk for adverse health outcomes compared with conventional sleep scoring. 17 , 18 , 19 , 20 However, few studies have investigated the association between sleep microstructure and future development of hypertension. One study performed in a small sample of middle‐aged women showed that those with low delta power during NREM sleep may be at increased risk of developing hypertension.…”

“…One study performed in a small sample of middle‐aged women showed that those with low delta power during NREM sleep may be at increased risk of developing hypertension. 21 However, obstructive sleep apnea was not controlled for, which clearly impacts quantitative EEG, 19 and thus may have confounded the association with hypertension.…”