Comparing the cardiac autonomic activity profile of daytime naps and nighttime sleep
Heart rate variability (HRV) is a reliable technique to evaluate autonomic activity and shows marked changes across a night of sleep. Previous nighttime sleep findings report changes in HRV during non-rapid eye movement sleep (NREM), which have been associated with cardiovascular health benefits. Da...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2018-06-01
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| Series: | Neurobiology of Sleep and Circadian Rhythms |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2451994417300172 |
| _version_ | 1819275302660997120 |
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| author | Lauren N. Whitehurst Mohsen Naji Sara C. Mednick |
| author_facet | Lauren N. Whitehurst Mohsen Naji Sara C. Mednick |
| author_sort | Lauren N. Whitehurst |
| collection | DOAJ |
| description | Heart rate variability (HRV) is a reliable technique to evaluate autonomic activity and shows marked changes across a night of sleep. Previous nighttime sleep findings report changes in HRV during non-rapid eye movement sleep (NREM), which have been associated with cardiovascular health benefits. Daytime sleep, however, has been linked with both positive and negative cardiovascular outcomes. Yet, no studies have directly compared HRV profiles during an ecologically-valid daytime nap in healthy, well-rested adults to that of nighttime sleep. Using a within-subjects design, 32 people took a daytime nap and slept overnight in the lab at least one week apart; both sleep sessions had polysomnography, including electrocardiography (ECG), recorded. We measured inter-beat intervals (RR), total power (TP), low frequency power (LF; .04–.15 Hz), and high frequency power (HF; .15–.40 Hz) components of HRV during NREM and rapid eye movement (REM) sleep. Compared to the nap, we found longer RR intervals and decreased heart rate during the night for both Stage 2 and SWS and increased TP, LF and HF power during nighttime Stage 2 sleep only; however, no differences in the LFHF ratio or normalized HF power were found between the nap and the night. Also, no differences in REM sleep between the nap and night were detected. Similar relationships emerged when comparing the nap to one cycle of nighttime sleep. These findings suggest that longer daytime naps, with both SWS and REM, may provide similar cardiovascular benefits as nocturnal sleep. In light of the on-going debate surrounding the health benefits and/or risks associated with napping, these results suggest that longer daytime naps in young, healthy adults may support cardiac down-regulation similar to nighttime sleep. In addition, napping paradigms may serve as tools to explore sleep-related changes in autonomic activity in both healthy and at-risk populations. Keywords: Napping, Cardiovascular, Health, Heart rate variability, Autonomic, sleep |
| first_indexed | 2024-12-23T23:22:10Z |
| format | Article |
| id | doaj.art-567609394629415aad819607a739754e |
| institution | Directory Open Access Journal |
| issn | 2451-9944 |
| language | English |
| last_indexed | 2024-12-23T23:22:10Z |
| publishDate | 2018-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Neurobiology of Sleep and Circadian Rhythms |
| spelling | doaj.art-567609394629415aad819607a739754e2022-12-21T17:26:19ZengElsevierNeurobiology of Sleep and Circadian Rhythms2451-99442018-06-0155257Comparing the cardiac autonomic activity profile of daytime naps and nighttime sleepLauren N. Whitehurst0Mohsen Naji1Sara C. Mednick2Department of Psychology, University of California, 900 University Ave Riverside, Riverside 92507, CA, USA; Corresponding author.Department of Medicine, University of California San Diego, La JollaDepartment of Cognitive Sciences, University of California, IrvineHeart rate variability (HRV) is a reliable technique to evaluate autonomic activity and shows marked changes across a night of sleep. Previous nighttime sleep findings report changes in HRV during non-rapid eye movement sleep (NREM), which have been associated with cardiovascular health benefits. Daytime sleep, however, has been linked with both positive and negative cardiovascular outcomes. Yet, no studies have directly compared HRV profiles during an ecologically-valid daytime nap in healthy, well-rested adults to that of nighttime sleep. Using a within-subjects design, 32 people took a daytime nap and slept overnight in the lab at least one week apart; both sleep sessions had polysomnography, including electrocardiography (ECG), recorded. We measured inter-beat intervals (RR), total power (TP), low frequency power (LF; .04–.15 Hz), and high frequency power (HF; .15–.40 Hz) components of HRV during NREM and rapid eye movement (REM) sleep. Compared to the nap, we found longer RR intervals and decreased heart rate during the night for both Stage 2 and SWS and increased TP, LF and HF power during nighttime Stage 2 sleep only; however, no differences in the LFHF ratio or normalized HF power were found between the nap and the night. Also, no differences in REM sleep between the nap and night were detected. Similar relationships emerged when comparing the nap to one cycle of nighttime sleep. These findings suggest that longer daytime naps, with both SWS and REM, may provide similar cardiovascular benefits as nocturnal sleep. In light of the on-going debate surrounding the health benefits and/or risks associated with napping, these results suggest that longer daytime naps in young, healthy adults may support cardiac down-regulation similar to nighttime sleep. In addition, napping paradigms may serve as tools to explore sleep-related changes in autonomic activity in both healthy and at-risk populations. Keywords: Napping, Cardiovascular, Health, Heart rate variability, Autonomic, sleephttp://www.sciencedirect.com/science/article/pii/S2451994417300172 |
| spellingShingle | Lauren N. Whitehurst Mohsen Naji Sara C. Mednick Comparing the cardiac autonomic activity profile of daytime naps and nighttime sleep Neurobiology of Sleep and Circadian Rhythms |
| title | Comparing the cardiac autonomic activity profile of daytime naps and nighttime sleep |
| title_full | Comparing the cardiac autonomic activity profile of daytime naps and nighttime sleep |
| title_fullStr | Comparing the cardiac autonomic activity profile of daytime naps and nighttime sleep |
| title_full_unstemmed | Comparing the cardiac autonomic activity profile of daytime naps and nighttime sleep |
| title_short | Comparing the cardiac autonomic activity profile of daytime naps and nighttime sleep |
| title_sort | comparing the cardiac autonomic activity profile of daytime naps and nighttime sleep |
| url | http://www.sciencedirect.com/science/article/pii/S2451994417300172 |
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