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Altered heart rate variability during sleep in mild cognitive impairment
Shawn D X Kong1,2,3,4, Camilla M Hoyos1,2,3,4,5, Craig L Phillips4,5,6,7
1School of Psychology, Faculty of Science, University of Sydney, Camperdown, NSW, Australia.
Sleep
|December 11, 2020
Summary
Older adults with amnestic mild cognitive impairment (MCI) show reduced heart rate variability (HRV) during NREM sleep compared to those with subjective cognitive impairment (SCI). This suggests sleep-related parasympathetic dysfunction may be an early dementia biomarker.
Area of Science:
- Neurology
- Cardiology
- Sleep Medicine
Background:
- Cardiovascular autonomic dysfunction is linked to mild cognitive impairment (MCI) in older adults.
- Previous research focused on diurnal heart rate variability (HRV), leaving sleep-related autonomic function in MCI unclear.
Purpose of the Study:
- To compare overnight HRV during sleep in older adults with MCI versus subjective cognitive impairment (SCI).
- To investigate sleep-stage specific autonomic dysfunction in MCI.
Main Methods:
- Overnight polysomnography was performed on 210 older adults diagnosed with MCI or SCI.
- Power spectral analysis of HRV, focusing on high-frequency HRV (HF-HRV) for parasympathetic activity, was conducted across sleep stages (NREM, REM) and wake periods.
Main Results:
- The MCI group exhibited significantly reduced HF-HRV during Non-Rapid Eye Movement (NREM) sleep compared to the SCI group.
- Amnestic MCI (aMCI) participants showed the most pronounced HF-HRV reduction across all NREM stages (N1, N2, N3) versus SCI.
- No significant HF-HRV differences were observed during wake or REM sleep between groups.
Conclusions:
- Reduced HF-HRV during NREM sleep in aMCI suggests potential sleep-related parasympathetic dysfunction.
- HF-HRV during NREM sleep may serve as an early biomarker for dementia detection.
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