Comparison of autonomic activity between N2 and N3 stages of NREM sleep: evaluation through heart rate variability metrics

Background: Low-intensity resistance training (RT) combined with neuromuscular electrical stimulation (NMES) is one method of exercise to improve the deterioration of physical function. However, it is unclear whether low-intensity RT combined with NMES (RT + NMES) can be safely implemented. Objective: This study aimed to examine the influence of low-intensity RT + NMES on autonomic activity and cardiovascular responses in healthy adults. Methods: This study was an open-label, randomized controlled cross-over trial. The exercise intensity of isometric knee extension RT was set to 40% of the maximum voluntary contraction (peak torque). NMES was adjusted to a biphasic asymmetrical waveform with the frequency maintained at 50 Hz and a phase duration of 300 [Formula: see text]s. The difference in the change in autonomic activity and cardiovascular responses was compared by assessing heart rate variability, blood pressure, and heart rate during RT and [Formula: see text]. Results: Twenty healthy male college students (mean age [Formula: see text] years) participated in this study. The ratio of low- and high-frequency components of heart rate variability, systolic blood pressure, and heart rate increased during exercise in the RT and [Formula: see text] sessions ([Formula: see text]). There were no significant differences in autonomic activity and cardiovascular responses throughout the sessions during RT and [Formula: see text]. Conclusion: In conclusion, our results demonstrated that low-intensity [Formula: see text] was safe and did not induce excessive autonomic and cardiovascular responses in healthy adults.

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Heart Rate Variability during wake and sleep in Huntington’s Disease patients. An observational, cross-sectional, cohort study.

Neurodegenerative Diseases ◽

10.1159/000520754 ◽

2021 ◽

Author(s):

Jessica Marotta ◽

Carla Piano ◽

VALERIO BRUNETTI ◽

Danilo Genovese ◽

Anna Rita Bentivoglio ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Huntington's Disease ◽

Huntington’S Disease ◽

Rem Sleep ◽

Low Frequency ◽

Nrem Sleep ◽

Control Group ◽

Cross Sectional ◽

Mean Heart Rate

Introduction Autonomic dysfunction has been reported as one of non-motor manifestations of both pre-symptomatic and manifest Huntington’s Disease (HD). The aim of our study was to evaluate heart rate variability (HRV) during wake and sleep in a cohort of patients with manifest HD. Methods Thirty consecutive patients with manifest HD were enrolled, 14 men and 16 women, mean age 57.3±12.2 years. All patients underwent full-night attended video-polysomnography. HRV was analyzed during wake, NREM and REM sleep, in time and frequency domain. Results were compared with a control group of healthy volunteers matched for age and sex. Results During wake HD patients presented significantly higher mean heart rate than controls (72.4±9.6 vs 58.1±7.3 bpm; p<0.001). During NREM sleep, HD patients showed higher mean heart rate (65.6±11.1 vs 48.8±4.6 bpm; p<0.001) and greater Low Frequency (LF) component of HRV (52.9±22.6 vs 35.5±17.3 n.u.; p=0.004). During REM sleep, we observed lower standard deviation of the R-R interval (SDNN) in HD subjects (3.4±2.2 vs 3.7±1.3 ms; p=0.015). Conclusion Our results showed that HD patients have higher heart rate than controls, during wake and NREM, but not during REM sleep. Among HRV variability parameters, the most relevant difference regarded the LF component, which reflects, at least partially, the ortho-sympathetic output. Our results confirm the involvement of autonomic nervous system in HD and demonstrate that it is evident during both wake and sleep.

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