Subjective Sleep Questionnaires Research Articles

Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality

Tart Montmorency cherries have been reported to contain high levels of phytochemicals including melatonin, a molecule critical in regulating the sleep-wake cycle in humans. The aim of our investigation was to ascertain whether ingestion of a tart cherry juice concentrate would increase the urinary melatonin levels in healthy adults and improve sleep quality. In a randomised, double-blind, placebo-controlled, crossover design, 20 volunteers consumed either a placebo or tart cherry juice concentrate for 7 days. Measures of sleep quality recorded by actigraphy and subjective sleep questionnaires were completed. Sequential urine samples over 48 h were collected and urinary 6-sulfatoxymelatonin (major metabolite of melatonin) determined; cosinor analysis was used to determine melatonin circadian rhythm (mesor, acrophase and amplitude). In addition, total urinary melatonin content was determined over the sampled period. Trial differences were determined using a repeated measures ANOVA. Total melatonin content was significantly elevated (P < 0.05) in the cherry juice group, whilst no differences were shown between baseline and placebo trials. There were significant increases in time in bed, total sleep time and sleep efficiency total (P < 0.05) with cherry juice supplementation. Although there was no difference in timing of the melatonin circardian rhythm, there was a trend to a higher mesor and amplitude. These data suggest that consumption of a tart cherry juice concentrate provides an increase in exogenous melatonin that is beneficial in improving sleep duration and quality in healthy men and women and might be of benefit in managing disturbed sleep.

Polysomnographic and quantitative electroencephalographic correlates of subjective sleep complaints in chronic tinnitus

Chronic tinnitus, or the perception of hearing sounds without the presence of external stimulation, is estimated at about 10-15% of the population, with highest prevalence after 50 years of age. Sleep complaints are among the most prominent complaints accompanying tinnitus, but objective data are rare. In this study, we examined prospectively the subjective and objective sleep parameters of this patient population in order to determine differences in sleep disturbances associated with chronic tinnitus compared to matched controls. Forty-four subjects (22 with tinnitus and 22 controls without tinnitus), unselected with respect to sleep complaints, participated in this study. The analysis involved 1-week sleep diaries, subjective sleep questionnaires and 1 night of polysomnographic (PSG) assessment. Compared to matched controls, the tinnitus group showed lower subjective sleep quality as measured with the Pittsburgh Sleep Quality Index (PSQI) and sleep diaries, but no significant difference in objective polysomnograph sleep parameters (i.e. sleep latency, efficiency). However, quantitative non-rapid eye movement sleep analysis revealed lower spectral power in the delta frequency band in the tinnitus group compared to controls, and this decrease was correlated with subjective sleep complaints (the lower the delta spectral power, the greater the complaints). This is the first report of an electrophysiological correlate of sleep difficulties supportive of subjective sleep complaints in the tinnitus population.

Factors Related to Sleep Apnea Syndrome in Sleep Clinic Patients

We examined 129 patients recruited from two sleep clinics to study the sleep apnea syndrome (SAS), defined by the apnea-hypopnea index (AHI) > or = 10. Information was registered from a self-administered questionnaire, basal physical measurements, and polysomnography. In 68 subjects recorded for two consecutive nights, a high correlation was found between first- and second-night AHIs (r = 0.89). Habitual loud snoring and breathing arrests during sleep were associated with AHI > or = 10. A model including these two variables, sex, age, and body mass index was created in order to predict AHI > or = 10 and with which it was possible to successfully classify almost three of four patients. Among subjective sleep questionnaire items, only daytime sleepiness was related to drops of transcutaneous oxygen tension. These discrepancies in the observed relationship between sleep parameters and subjective sleep items reduce the questionnaire value in epidemiologic settings where it aimed to detect SAS, as defined solely by the AHI value.

Long-term study of the sleep of insomnia patients with sleep state misperception and other insomnia patients.

The objectives were 1) to investigate differences among patients with subjective insomnia (sleep state misperception), patients with objective findings of insomnia, and normal volunteers and 2) to assess the consistency of the sleep findings during a 2-month period. Twenty-one subjects were studied. Subjects with sleep state misperception (N = 7) had insomnia complaints for more than 1 year, no objective sleep disturbance, and sleep efficiency of 90% or greater (on the diagnostic screening sleep recording), while subjectively estimating that sleep time was less than 6.5 hours. Subjects with objective insomnia (N = 7) met the same subjective criteria, but objectively sleep efficiency was 85% or less. Normal subjects (N = 7) had no insomnia complaints and objective sleep efficiency of 90% or greater. All subjects were recorded on 2 consecutive nights three times with a 3-week period between each pair of nights (6 standard all-night polysomnographic sessions of 8 hours). A subjective sleep questionnaire was administered after each sleep recording night. Sleep stage variables (percentages) were similar between the two insomnia groups, and both were different from the normal subjects. Sleep continuity variables were disturbed in the objective insomnia group, but they were similar in the sleep state misperception and normal groups. Both insomnia groups rated their sleep as inadequate on the questionnaires and differed from the normal subjects. The distinct sleep patterns of each of the three groups did not vary over the 6 nights of assessment. Sleep state misperception may be a prodromic or transitional state of sleep dysfunction between normal sleep and the sleep pattern of objective insomnia.