Sleep structure and electroencephalographic spectral power of middle‐aged or older adults: Normative values by age and sex in the Korean population

Abstract

The fine structure of sleep electrocortical activity reflects health and disease. The current study provides normative data for sleep structure and electroencephalography (EEG) spectral power measures derived from overnight polysomnography (PSG) and examines the effect of age and sex among Korean middle‐aged and older adults with or without obstructive sleep apnea (OSA). We analysed home PSG data from 1,153 adult participants of an ongoing population‐based cohort study, the Korean Genome and Epidemiology Study. Sleep stages were visually scored and spectral power was measured on a single‐channel EEG (C4‐A1). We computed spectral power for five frequency ranges. The EEG power was reported in relative (%) and log‐transformed absolute values (µV2). With ageing, the proportion of N1 sleep increased, whereas N3 decreased, which is more noticeable in men than in women. The amount of N3 was relatively low in this cohort. With ageing, relative delta power decreased and alpha and sigma power increased for the whole sleep period, which was more pronounced during REM sleep in non‐OSA. For men compared with women, relative theta power was lower during REM and sigma and beta were higher during N1 sleep. The differences of relative powers by age and sex in OSA were comparable to those in non‐OSA. In a community‐based Korean population, we present normative data of sleep structure and spectral power for middle‐aged or older adults of a non‐Caucasian ethnicity. The values varied with age and sex and were not influenced by sleep apnea.

Bidirectional associations between physical activity and sleep in older adults: a multilevel analysis using polysomnography

“…In the present study, we examined the bidirectional associations between physical activity and both objective and subjective sleep quality in older adults. Our analysis revealed that the characteristics of stage N3 sleep were better among our participants than among those included in a previous epidemiological study 28 . In 80% of younger adults, changes in sleep structure related to stage N3 appear within approximately 1 h after falling asleep 34 ; however, such changes occurred in only 20% of older adults in the current study (Fig.…”

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Sleep macro- and microstructure in breast cancer survivors

“…Beta band) 24 . With healthy ageing, previous reports have shown that Delta power decreases and Alpha and Sigma power increase, indicating that sleep becomes lighter with age 25 , 26 . In insomnia disorder, a recent meta-analysis reported increased Alpha, Sigma and Beta power and lower Delta power compare to healthy adults, notably during NREM sleep 27 .…”

The multidimensionality of sleep in population‐based samples: a narrative review

“…the likely benefit of an increased length and intensity of their SWS, at least until they reach menopause (Choi et al, 2019;Roehrs et al, 2006;Yoon et al, 2021). Although the percentage of SWS and the slow-wave activity power markedly decrease in both men and women as they get older, the sleep of men is characterised by a steeper decline in these measures and a higher arousal index (Baker et al, 2016;Mallampalli & Carter, 2014;Moraes et al, 2014;Redline et al, 2004;.…”

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