Effects of environment light during sleep on autonomic functions of heart rate and breathing
Poor sleep hygiene including sleeping in the daytime or with the lights on at night is discovered during the assessment of many sleep disorders including sleep apnea. The aim of this study was to investigate whether environmental light affected autonomic control of heart rate, sleep-disordered breathing (SDB), and/or breathing patterning.
Seventeen non-obese healthy volunteers without witnessed snoring and apneas were recruited. Studies were performed at home using a type 3 portable monitor combined with actigraphy for sleep-wake timing, using a randomly assigned, crossover between dark, or 1,000 lx of fluorescent lighting environment. The outcomes were low-frequency power divided by high-frequency power (LF/HF ratio) in the analysis of heart rate variability, the apnea-hypopnea index (AHI), and ventilatory pattern variability before and after sleep onset between environments.
The LF/HF ratio and AHI were both significantly higher in light as compared to dark. Before sleep onset, the coefficient of variation (CV) for breath-to-breath tidal volume representing breathing irregularity tended to be higher in light than in dark environment. The CV values for tidal volume after sleep onset were significantly decreased compared with before sleep onset in both sleep environments. Mutual information of the ventilatory pattern was significantly lower before sleep onset than after sleep onset, only in the light environment.
Sleeping in the light has effects like that of a stressor as it is associated with neuroexcitation, SDB, and resting breathing irregularity in healthy volunteers. These findings may be relevant to many sleep disorders associated with poor sleep hygiene.
KeywordsObstructive sleep apnea Sleep environment Sleep hygiene Sympathetic nerve activity Resting breathing irregularity
Body mass index
Nasal continuous positive airway pressure
Coefficient of variation
- LF/HF ratio
Low-frequency power divided by high-frequency power in the analysis of heart rate variability
Obstructive sleep apnea syndrome
Respiratory inductance plethysmography
Breath-to-breath respiratory duration
This study is partly supported by a grant to the Comprehensive Research on Life-Style Related Diseases including Cardiovascular Diseases and Diabetes Mellitus Group from the Ministry of Health, Labor and Welfare of Japan. US investigators were supported in part by the NIH-NHLBI [R33HL087340-01] and Award Number I01BX000873 from the Biomedical Laboratory Research and Development Service of the VA Office of Research and Development.
Conflict of interest
None of the authors have financial conflicts of interest to declare as it relates to the contents of this manuscript.
- 19.Collop NA, Anderson WM, Boehlecke B, Claman D, Goldberg R, Gottlieb DJ, Hudgel D, Sateia M, Schwab R (2007) Clinical guidelines for the use of unattended portable monitors in the diagnosis of obstructive sleep apnea in adult patients. Portable Monitoring Task Force of the American Academy of Sleep Medicine. J Clin Sleep Med 3(7):737–747PubMedGoogle Scholar
- 26.Gangwisch JE, Heymsfield SB, Boden-Albala B, Buijs RM, Kreier F, Pickering TG, Rundle AG, Zammit GK, Malaspina D (2006) Short sleep duration as a risk factor for hypertension: analyses of the first National Health and Nutrition Examination Survey. Hypertension 47(5):833–839PubMedCrossRefGoogle Scholar