OBJECTIVE: Improving and validating sleep scoring algorithms for actigraphs enhances their usefulness in clinical and research applications. The MTI® device (ActiGraph, Pensacola, FL) had not been previously validated for sleep. The aims were to (1) compare the accuracy of sleep metrics obtained via wrist- and hip-mounted MTI® actigraphs with polysomnographic (PSG) recordings in a sample that included both normal sleepers and individuals with presumed sleep disorders; and (2) develop a novel sleep scoring algorithm using spline regression to improve the correspondence between the actigraphs and PSG.
METHODS: Original actigraphy data were amplified and their pattern was estimated using a penalized spline. The magnitude of amplification and the spline were estimated by minimizing the difference in sleep efficiency between wrist- (hip-) actigraphs and PSG recordings. Sleep measures using both the original and spline-modified actigraphy data were compared to PSG using the following: mean sleep summary measures; Spearman rank-order correlations of summary measures; percent of minute-by-minute agreement; sensitivity and specificity; and Bland-Altman plots.
RESULTS: The original wrist actigraphy data showed modest correspondence with PSG, and much less correspondence was found between hip actigraphy and PSG. The spline-modified wrist actigraphy produced better approximations of interclass correlations, sensitivity, and mean sleep summary measures relative to PSG than the original wrist actigraphy data. The spline-modified hip actigraphy provided improved correspondence, but sleep measures were still not representative of PSG.
DISCUSSION: The results indicate that with some refinement, the spline regression method has the potential to improve sleep estimates obtained using wrist actigraphy.
Keywords: Actigraphy, Polysomnography, Penalized spline
OBJECTIVES: Previous studies have demonstrated that aerobic exercise interventions have a positive impact on sleep efficiency in older adults. However, little work has been done on the impact of sedentary behavior (sitting, watching television, etc.) on sleep efficiency.
METHODS: 54 Community-dwelling men and women > 65 years of age living in Whistler, British Columbia (mean 71.5 years) were enrolled in this cross-sectional observational study. Measures of sleep efficiency as well as average waking sedentary (ST), light (LT), and moderate (MT) activity were recorded with Sensewear accelerometers worn continuously for 7 days.
RESULTS: From the univariate regression analysis, there was no association between sleep efficiency and the predictors LT and MT. There was a small negative association between ST and sleep efficiency that remained significant in our multivariate regression model containing alcohol consumption, age and gender as covariates. (standardized fi correlation coefficient - 0.322, p=0.019). Although significant, this effect was small (an increase in sedentary time of 3 hours per day was associated with an approximately 5% reduction in sleep efficiency).
CONCLUSIONS: This study found a small significant association between the time spent sedentary and sleep efficiency, despite high levels of activity in this older adult group.
Keywords: Sedentary behavior, Sleep efficiency, Geriatric medicine, Accelerometer, Physical activity
INTRODUCTION: Previous research had shown the suitability of several questionnaires predicting the obstructive sleep apnea syndrome. Measurement properties of an online screening questionnaire were studied.
METHODS: The sample consisted of 184 Portuguese adults (89 men and 95 women); 46 of them were polysomnographically diagnosed with the untreated obstructive sleep apnea syndrome. The participants were assessed with an online questionnaire of sleep apnea risk, from University of Maryland.
RESULTS: A principal component factor analysis was performed, revealing a single factor (49.24% of the total variance). Internal consistency was minimally adequate (a=0.74). The mean of inter-item correlation was of 0.35 (0.12
Furthermore, the ability of the measure in discriminating between healthy subjects and OSA subjects was good. Overall data from the Rasch analysis was consistent with the guidelines of Linacre, scores show good model fit and psychometric adequacy.
CONCLUSIONS: The measure showed an adequate structural, internal and criterion validity, suggesting this as a useful and effective screening for sleep apnea risk in Portuguese adults.
Keywords: Sleep Apnea Risk, Questionnaires, Screening, Classical measurement theory, Rasch rating scale model
OBJECTIVE: The aim of this study was to identify chronotypes of medical students at the Federal University of Paraíba (UFPB) and its relationship to quality of sleep, daytime sleepiness, age, sex and season of birth.
METHODS: The final sample consisted of 221 students, assessed by four questionnaires: demographic questionnaire, Morningness-Eveningness Questionnaire (MEQ), Pittsburgh Sleep Quality lndex (PSQI) and Epworth Sleepiness Scale (ESS).
RESULTS: There was a statistically significant difference between groups with respect to chronotypes and PSQI score (p< 0.0005), but not with excessive daytime sleepiness. A significant negative correlation was found between the scores of MEQ and PSQI (rho = -0.3, p<0.0005), demonstrating that the greater the eveningness, the worse the sleep quality. It was observed that 51.6% of students were classified as indifferent chronotype, 61.5% had poor quality of sleep, while 42.1% had excessive daytime sleepiness. Sex and season at birth did not differ between chronotypes.
CONCLUSION: These findings demonstrate that the evening chronotype was associated with poor quality of sleep in medical students, but not with increased daytime sleepiness, with potential impairment to their academic performance and quality of life.
Keywords: Chronobiology phenomena, Sleep deprivation, Medical students
PURPOSE: To describe the SpO2 in wakefulness, sleep and during the apnea-hypopnea in adults living in Bogotá, located at 2640 m above sea level.
METHODS: Descriptive observational study in adults referred for polysomnogram (PSG). A normal Apnea hypopnea index (AHI) was defined as ≤ 5 and obstructive sleep apnea (OSA) was classified as mild (AHI 5-15), moderate (AHI 15-30), and severe (AHI >30). T-test or ANOVA test for SpO2 differences between groups was used.
RESULTS: 1799 patients, 33% women. 222 (12.8%) did not have OSA (normal IAH), 268 (14.9%) mild OSA, 315 (17.5%) moderate ,and 993 (55.2%) severe. In all cases a low SpO2 (SpO2<90%) was found.
The SpO2 was lower when the AHI was higher, in wakefulness, in non-REM and in REM (p< 0.001). For all grades of severity, SpO2 decreased significantly from wakefulness to non-REM sleep and to REM sleep (p<0.001). Patients with severe OSA had higher desaturation during wakefulness (85.2±6.6%), non-REM sleep (83.1±7.7%), REM sleep (78.8±10.2), and during events (75.1±9.1%).
CONCLUSIONS: Patients with OSA at 2640 m have nocturnal desaturation lower than 88%, which decreases with higher severity of OSA. The clinical impact of sleep disorders at this point may be greater than at sea level and should be studied.
Keywords: Sleep apnea, High altitude, Oxygen saturation
PURPOSE: To review the association between sleep duration and self-rated health.
METHODS: A search for original and review articles focusing on sleep duration and self-rated health was performed in PubMed. The general search strategy was [(“sleep duration” OR “total sleep time” OR “time in bed”) AND “self-rated health”].
RESULTS: We found 22 articles in the English language; 8 articles with no direct association between sleep duration and self-rated health were excluded. Of these articles, 14 were considered potentially relevant and examined in detail, and 9 were excluded for not having self-rated health as the primary outcome. This work was compounded by 5 papers. The extremes of sleep duration (short or long) exhibited an interaction with poor or worse selfrated health.
CONCLUSION: The sleep duration issue should be considered when inquiring about health conditions, as this factor can lead to adverse results in global health status.
Keywords: Sleep, Sleep duration (SD), Health, Self-rated health (SRH)
With increases life expectancy, the incidence of undesirable manifestations of menopause has increased as well. The effects of lost ovarian function include progressive decrease in estradiol secretion, trophic changes in the breast, vasomotor symptoms, anxiety, depression, and sleep disorders. Insomnia, which has physiological consequences and can result in a loss of quality of life, is prevalent in women after menopause. Hormone therapy has been widely used to reduce menopausal symptoms, but its use in recent years has been questioned because of the reported risks of cardiovascular events and increased incidence of tumors. This controversy has generated significant interest in non-hormonal treatments among both physicians and patients. Our previous research has shown a positive effect of massage therapy on menopausal symptoms. We explored the hypothesis that massage therapy would produce beneficial effects in postmenopausal women through inflammatory and immunological changes. Recent results from self-report questionnaires have shown improvements in sleep pattern and quality of life following massage therapy. These findings demonstrate the effectiveness of massage therapy for the treatment of postmenopausal symptoms, particularly insomnia, and indicate that it is a promising line of research.
Keywords: Sleep, Insomnia, Massage, Alternative methods, Post-menopause, Hormonal therapy
We are reporting a case of a 29 year-old female with diagnosis of myotonic dystrophy type 1 (Steinert’s disease) with excessive daytime sleepiness, muscle fatigue, snoring, frequent arousals, non-restorative sleep, and witnessed apneas. Pulmonary function tests revealed a mild decrease of forced vital capacity. Nocturnal polysomnography showed an increase of apnea/hypopnea index (85.9 events/h), mainly of central type (236), minimal oxygen saturation of 72%, and end-tidal carbon dioxide values that varied from 45 to 53 mmHg.
Bi-level positive airway pressure titration was initiated at an inspiratory pressure (IPAP) of 8 and an expiratory pressure (EPAP) of 4 cm H2O. IPAP was then gradually increased to eliminate respiratory events and improve oxygen saturation. An IPAP of 12cm H2O and an EPAP of 4cm H2O eliminated all respiratory events, and the oxygen saturation remained above 90%.
Bi-level positive airway pressure treatment at spontaneous/timed mode showed an improvement in snoring, apneas, and Epworth sleepiness scale decreased from 20 to 10. This case illustrates the beneficial effects of Bi-level positive airway pressure support in central sleep apnea syndrome of a patient with myotonic dystrophy type 1.
Keywords: Central sleep apnea syndrome, Myotonic dystrophy type 1, Bi-level positive airway pressure
The Kleine-Levin Syndrome is a differential diagnosis for patients with diurnal excessive sleepiness and a suspicion of narcolepsy. It is characterized by paroxysmal attacks of diurnal excessive sleepiness, associated with one or more symptoms of hyperphagia, hypersexuality, coprolalia and copropraxia. During crisis intervals, there are no symptoms. This pathology predominantly manifests itself in teenagers, being more frequent among males. The course of this disease is unpredictable, with variable duration and frequency. The most accepted physiopathology is that of a hypothalamic dysfunction, although and recently, there has appeared a hypothesis of a post-infectious autoimmune disorder. These patients show an elevated body mass index, which can predispose to association with comorbidities such as the sleep obstructive apnea syndrome. Treatment involves medications with different effects, but there is no specific and effective therapy. Our article shows a classic case of Kleine-Levin Syndrome associated with sleep obstructive apnea syndrome, a rare association in the literature.
Keywords: Kleine-Levin Syndrome, Recurrent hypersleepiness, Sleep obstructive apnea syndrome