INTRODUCTIONPatients with obstructive sleep apnoea (OSA) often present with excessive daytime sleepiness (EDS) as measured by the Epworth Sleepiness Scale (ESS). However, the relationship between EDS and OSA severity as measured by the apnoea-hypopnoea index (AHI) remains inconsistent. We hypothesise that this may be due to the usage and equal weightage of apnoea and hypopnoea events used in determining AHI and that apnoea and hypopnoea load as measured by their total durations may be a better metric to use. We sought to investigate if apnoea or hypopnoea load can display better correlation with ESS.

MATERIALS AND METHODSRetrospective analysis of 821 patients with AHI ≥5, who underwent in-laboratory polysomnogram for suspected OSA from January 2015-December 2015, was performed. Objective factors on polysomnogram were correlated with ESS.

RESULTSESS was correlated with age (r = -0.148, <0.001), number of apnoeas (r = 0.096, = 0.006), apnoea load (r = 0.102, = 0.003), apnoea index (r = 0.075, = 0.032), number of desaturations (r = 0.081, = 0.020), minimum SpO (r = -0.071, = 0.041), time SpO <85% (r = 0.075, = 0.031) and REM sleep duration (r = 0.099, = 0.004). Linear regression analysis found age ( <0.001), apnoea load ( = 0.005), REM ( = 0.021) and stage 1 sleep duration ( = 0.042) as independent factors correlated to ESS. The apnoea load calculated using duration in apnoea correlate with ESS in patients with severe OSA by AHI criteria compared to the mild category.

CONCLUSIONAHI does not correlate with ESS. Younger age, longer apnoea, stage 1 and REM sleep were independently related to higher ESS though the correlations were weak. Apnoea load should be taken into account when determining OSA severity.

Adult ; Age Factors ; Disorders of Excessive Somnolence ; diagnosis ; etiology ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Polysomnography ; methods ; Retrospective Studies ; Severity of Illness Index ; Singapore ; Sleep Apnea Syndromes ; physiopathology ; Sleep Apnea, Obstructive ; complications ; diagnosis ; physiopathology ; Sleep, REM ; physiology ; Statistics as Topic

BackgroundRapid eye movement (REM) sleep behavior disorder (RBD) and obstructive sleep apnea (OSA) are the most common sleep disorders in Parkinson's disease (PD). The aim of this study was to identify whether RBD could alleviate OSA severity in PD patients and its effect on cognitive impairment.

MethodsFrom February 2014 to May 2017, we recruited 174 PD patients from the Second Affiliated Hospital of Soochow University, all of whom underwent polysomnography (PSG). We collected clinical data, PSG results, and compared information between patients with and without RBD or OSA by analysis of covariance. We also investigated the effect of these sleep disorders on cognitive impairment using linear regression.

ResultsWe grouped participants as follows: PD only (n = 53), PD + OSA (n = 29), PD + RBD (n = 61), and PD + RBD + OSA (n = 31). Minimum oxygen saturation (SaO) during whole sleep and in REM sleep was higher in PD + RBD + OSA patients than that in PD + OSA patients. PD + RBD patients had worse Mini-Mental Status Examination and Montreal Cognitive Assessment (MoCA) scores than those in the PD group (P < 0.001), especially in visuospatial/executive, attention, and memory functions. The PD + OSA group performed worse than the PD group in the delayed recall domain. After adjusting for age, sex, body mass index, education, disease severity, and other sleep disorders, MoCA was negatively associated with OSA (β = -0.736, P = 0.043) and RBD (β = -2.575,P < 0.001). The severity of RBD (tonic/phasic electromyography activity) and OSA (apnea-hypopnea index/oxygen desaturation index/minimum SaO) were also associated with MoCA. The adjusted β values of RBD-related parameters were higher than that for OSA.

ConclusionsWe found that RBD alleviated OSA severity; however, RBD and OSA together exacerbated PD cognitive impairment. Further studies are needed to evaluate whether OSA treatment can improve cognition in PD.

Aged ; Female ; Humans ; Linear Models ; Male ; Middle Aged ; Parkinson Disease ; pathology ; physiopathology ; Polysomnography ; REM Sleep Behavior Disorder ; pathology ; physiopathology ; Sleep Apnea, Obstructive ; pathology ; physiopathology ; Sleep, REM ; physiology

OBJECTIVE: The effect of transdermal nicotine patch on sleep physiology is not well established. The current study aimed to examine the influence of nicotine patch on homeostatic sleep propensity and autonomic nervous system. METHODS: We studied 16 non-smoking young healthy volunteers with nocturnal polysomnography in a double blind crossover design between sleep with and without nicotine patch. We compared the sleep variables, sleep EEG power spectra, and heart rate variability. RESULTS: The night with nicotine patch showed significant increase in sleep latency, wake after sleep onset, and stage 1 sleep; and decrease in total sleep time, sleep efficiency, and percentage of REM sleep. Also, spectral analysis of the sleep EEG in the night with nicotine patch revealed decreased slow wave activity in stage 2 and REM sleep and increased alpha activity in the first NREM-REM sleep cycle. Heart rate variability showed no differences between the 2 nights, but the low to high ratio (a parameter indicative of sympathetic nervous system activity) positively correlated with wake after sleep onset in night with nicotine patch. CONCLUSION: Transdermal nicotine patch significantly disrupts sleep continuity, sleep architecture, and homeostatic sleep propensity. The overactivation of the sympathetic nervous system may be responsible for these changes.
Adult* ; Autonomic Nervous System ; Cross-Over Studies ; Electroencephalography* ; Healthy Volunteers ; Heart Rate* ; Heart* ; Humans ; Male* ; Nicotine* ; Physiology ; Polysomnography ; Sleep, REM ; Spectrum Analysis ; Sympathetic Nervous System ; Tobacco Use Cessation Products*

The use of alcohol is associated with the development and worsening of sleep disorder. Alcohol is generally known to have a sedative effect, but it has an arousal or sedative effect depending on the timing and drinking dose and directly affects REM sleep physiology. Alcohol acts on the central nervous system (CNS) to interfere with the sleep-wake cycle and to affect sleep-related hormone secretion. In addition, the ingestion of alcohol pre-sleep is associated with deterioration and development of sleep related breathing disorders (SBD). The increase in resistance of the upper respiratory tract and the decrease in sensitivity of the CNS respiratory center and the respiratory muscles are major mechanisms of alcohol-induced SBD, and result in snoring or apnea in healthy men or aggravating apnea in patients with OSA. Sleep-related restless leg syndrome and circadian rhythm disorders are common in alcohol use disorder patients. This review provides an assessment of scientific studies that investigated on the impact of alcohol ingestion on nocturnal sleep physiology and sleep disorders.
Alcohols ; Apnea ; Arousal ; Central Nervous System ; Chronobiology Disorders ; Drinking ; Eating ; Humans ; Hypnotics and Sedatives ; Male ; Physiology ; Respiration ; Respiratory Center ; Respiratory Muscles ; Respiratory System ; Restless Legs Syndrome ; Sleep Apnea Syndromes ; Sleep Wake Disorders* ; Sleep, REM ; Snoring

Brain ; physiology ; History, 20th Century ; Humans ; Sleep ; physiology ; Sleep Medicine Specialty ; history ; Sleep, REM ; physiology

BACKGROUNDKleine-Levin syndrome (KLS) is a rare sleep disorder characterized by recurrent episodes of hypersomnia. Polysomnographic (PSG) researches of KLS have been reported only in few publications in the past decades. This study aimed to investigate the characteristics of PSG of KLS.

METHODSThis study, which was conducted from March 2010 to July 2014, included seven patients diagnosed with KLS in the Sleep and Wake Disorder Center of Huashan Hospital, Fudan University (Shanghai, China). PSG and multiple sleep latency tests (MSLT) were performed during their episodes and the results were evaluated.

RESULTSFive of the seven patients were males. The mean age at KLS onset was 15.6 ± 3.6 years. The number of episodes ranged from 2 to 7. The duration of episodes lasted from 4 to 11 days. The sleep architecture and proportion were normal in most of the patients. The average value of mean sleep latency was 6.9 ± 4.1 min. No sleep-onset rapid eye movement (SOREM) was detected in three of the patients, whereas one patient experienced one period of SOREM, and such episodes occurred twice in other two patients.

CONCLUSIONSWe found that sleep architecture and proportion were normal in most KLS patients. However, the results of PSG and MSLT had no specificity for KLS patients.

Adolescent ; Child ; China ; Female ; Humans ; Kleine-Levin Syndrome ; diagnosis ; physiopathology ; Male ; Polysomnography ; methods ; Retrospective Studies ; Sleep Wake Disorders ; physiopathology ; Sleep, REM ; physiology

Penile erection (PE) is a physiological phenomenon involving complex mechanisms. PE may occur as reactive erections, psychogenic erections in the conscious state and spontaneous erections during the sleep. Sleep-related PE refers to the erections occurring spontaneously during the sleep with rapid eye movement. Studies have shown a correlation between sleep and PE as well as between sleep disorders and erectile dysfunction but not yet revealed the exact mechanisms. This paper updates the relationship between sleep and erectile function.
Erectile Dysfunction ; etiology ; Humans ; Male ; Penile Erection ; physiology ; Sleep ; physiology ; Sleep Wake Disorders ; complications ; Sleep, REM ; physiology

BACKGROUNDRecent studies showed the central Na+/H+ exchanger type 3 (NHE3) has a close relationship with ventilation control. The objective of the study is to investigate the role of NHE3 in sleep apnea in Sprague-Dawley (SD) rats.

METHODSA sleep study was performed on 20 male SD rats to analyze the correlation between the sleep apneic events and total NHE3 protein content and inactive NHE3(pS552) in the brainstem measured by Western blotting. Another 20 adult male SD rats received 3 days of sleep and respiration monitoring for 6 hours a day, with adaption on the first day, 0.5% DMSO microinjection into the fourth ventricle on the second day, and AVE0657 (specific inhibitor of NHE3) microinjection on the third day. Rats were divided into two groups with injection of 5 µmol/L or 8 µmol/L AVE0657 before the sleep study. The effects of AVE0657 on sleep apnea and sleep structure of rats were analyzed through self-control.

RESULTSThe total post-sigh apnea index (TPSAI) and post-sigh apnea index in non-rapid eye movement (NREM) sleep (NPSAI) and total apnea index (AI) in NREM sleep (NAI) were negatively correlated with NHE3(pS552) protein contents in the brainstem (r = -0.534, -0.547 and -0.505, respectively, P < 0.05). The spontaneous apnea index in REM sleep (RSPAI) was positively correlated with the level of NHE3(pS552) protein expression in the brainstem (r = 0.556, P < 0.05). However, the sleep AI had no relationship with total NHE3 protein. Compared with the blank control and microinjection of 0.5% DMSO, 5 µmol/L AVE0657 significantly reduced the total AI and NPSAI (both P < 0.05) without a significant effect on sleep architecture. In contrast to blank control and microinjection of 0.5% DMSO, injection of 8 µmol/L AVE0657 significantly reduced the AI and PSAI in NREM and REM sleep (all P < 0.05).

CONCLUSIONSThe severity of sleep apnea was negatively correlated with central inactive NHE3. A specific inhibitor of NHE3 decreased the sleep AI. Thus, our results indicate that central NHE3 might be a molecular target for sleep apnea treatment, whose inhibitors may be potential therapeutic drugs for sleep apnea.

Animals ; Male ; Rats ; Rats, Sprague-Dawley ; Sleep Apnea Syndromes ; metabolism ; physiopathology ; Sleep, REM ; physiology ; Sodium-Hydrogen Exchanger 3 ; Sodium-Hydrogen Exchangers ; antagonists & inhibitors ; metabolism

Sleep is a highly organized and complicated state that is fundamental to life. We have an absolute need to sleep during about one-third of our lives. There are two types of sleep, non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. NREM sleep is divided into stages 1, 2, and 3 which is representing a degree of relative depth in sleep. Each sleep stage shows unique features including some variations in electroencephalographic waves, eye movements, and muscle tone. Although sleep pattern changes are associated with aging, how sleep physiology and sleep patterns change over an individual's life span is not well-defined. Circadian rhythms, which are the daily rhythms in physiology and behavior, regulate the sleep-wake cycle. Comprehensive understanding of normal sleep physiology should be very important to better understand not only the effects of sleep related diseases but also the impacts of pathological sleep on various diseases of other systemic organs. This review aims to enhance knowledge focused on normal sleep physiology and its regulation.
Aging ; Circadian Rhythm ; Eye Movements ; Muscles ; Neurobiology ; Physiology* ; Sleep Stages ; Sleep, REM

Depression and insomnia are intimately related. Depressed patients usually manifest sleep discontinuity and early awakening, reduced or no slow wave sleep (SWS) and shortened latency of rapid eye movement (REM) sleep. These sleep abnormalities are very similar to those caused by over activated hypothalamic-pituitary-adrenal (HPA) axis with stress. Therefore, the animal models developed by post-traumatic stress disorder or chronic unpredictable mild stress could be used to evaluate drugs which have effects of both anti-depression and improvement of sleep quality, and to provide a more reliable platform for further studis on the mechanisms of depression and accompanied insomnia. This review mainly focuses on the typical features of sleep disturbance of depression, possible pathophysiological mechanisms, establishment of animal stress models and analysis of their abnormal sleep characteristics.
Animals ; Chronic Disease ; Depression ; physiopathology ; Depressive Disorder ; physiopathology ; Disease Models, Animal ; Humans ; Hypothalamo-Hypophyseal System ; physiopathology ; Pituitary-Adrenal System ; physiopathology ; Sleep ; physiology ; Sleep Initiation and Maintenance Disorders ; physiopathology ; Sleep, REM ; Stress Disorders, Post-Traumatic ; physiopathology ; Stress, Psychological ; physiopathology