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Biomedical subjects

D J Mullaney

Publications and source records attributed to D J Mullaney.

13 recordsLinked to original sources
PubMed1997

Prevalence of sleep-disordered breathing in ages 40-64 years: a population-based survey.

Previous research has offered widely varying prevalence estimates for sleep apnea in the population, leaving uncertain which breathing patterns are abnormal. To explore the distribution of sleep apnea in the population and its co-morbidities, random telephone dialing was used between 1990 and 1994 to recruit subjects for a prevalence survey of sleep-disordered breathing in San Diego adults. Events from which blood oxygen desaturations > or = 4% resulted were monitored with home recording instruments, usually for three consecutive nights. Among 190 women ages 40-64 years, a median of 4.3 desaturation events per hour of sleep were observed. A higher median of 6.7 events per hour was observed among 165 men. Frequencies were much higher among members of minority groups, leading to a standard estimate that 16.3% of U.S. Hispanics and racial minorities have > or = 20 events/hour as compared to 4.9% of non-Hispanic Whites ages 40-64. Obesity indicated by body-mass index was the most important demographic predictor of sleep-disordered breathing, followed by age, male gender, and ethnicity. Quality of well-being was not significantly impaired in subjects with more respiratory events; however, there was some increase in blood pressure and wake-within-sleep associated with sleep-disordered breathing. This survey indicates that sleep-disordered breathing is more common, especially among minorities, than had been previously believed, but less co-morbidity may be associated.

Adult↗
PubMed1992

Controlled trial of bright light for nonseasonal major depressive disorders.

Psychotropic drug-free hospitalized veterans with nonseasonal major depressive disorders or depressed forms of bipolar disorder were treated with light for 1 week. Twenty-five patients were randomly assigned to bright white light treatment (2000-3000 lux), and 26 patients were randomized to dim red light placebo control treatment. Unlike those treated with dim red light, those treated with bright white light showed declines in three measures of depression during treatment. Partial relapse appeared within 2 days. A global depression score showed a statistically significant (p = 0.02) difference favoring bright white light treatment. Two bright-light-treated patients became mildly hypomanic, but side effects were mild. Improvement was not correlated with patient expectations; indeed, patients expected somewhat greater benefit from the placebo. Patients treated in summer responded as well as those treated in winter. Baseline electroencephalogram (EEG) sleep stage data (e.g., rapid eye movement; REM latency) did not predict treatment responses. These 1-week treatment results suggest that bright light might produce benefits for patients with nonseasonal depression. Bright light should not be recommended for routine clinical application before additional assessments with longer treatment durations are done.

Adult↗
PubMed1992

Automatic sleep/wake identification from wrist activity.

The purpose of this study was to develop and validate automatic scoring methods to distinguish sleep from wakefulness based on wrist activity. Forty-one subjects (18 normals and 23 with sleep or psychiatric disorders) wore a wrist actigraph during overnight polysomnography. In a randomly selected subsample of 20 subjects, candidate sleep/wake prediction algorithms were iteratively optimized against standard sleep/wake scores. The optimal algorithms obtained for various data collection epoch lengths were then prospectively tested on the remaining 21 subjects. The final algorithms correctly distinguished sleep from wakefulness approximately 88% of the time. Actigraphic sleep percentage and sleep latency estimates correlated 0.82 and 0.90, respectively, with corresponding parameters scored from the polysomnogram (p < 0.0001). Automatic scoring of wrist activity provides valuable information about sleep and wakefulness that could be useful in both clinical and research applications.

Adult↗
PubMed1984

Theophylline delays human sleep phase.

Twelve healthy male volunteers were given theophylline 250 mg in order to test effects on 24-hr rhythms. Rhythms of sleep/wake and subjective sleepiness were delayed. Ingestion of xanthines such as theophylline in coffee, tea, colas and chocolate may contribute to some sleep disorders. Theophylline might likewise be useful in treating disorders of circadian oscillators.

Adult↗
PubMed1982

An activity-based sleep monitor system for ambulatory use.

Wrist activity measured with a piezoceramic transducer was digitized and analyzed together with subjects' sleep/wake status to derive an optimal method for automatic computer sleep/wake scoring. Several algorithms for quantifying periods of activity were considered, and an algorithm that summed changes in activity level over a 2-s interval was found most sensitive. A computer program for scoring sleep/wake from the resulting digital activity records was then developed, and parameters derived by comparison with subjects' sleep/wake status as determined by EEG. EEG and activity sleep/wake scores agreed 94.46% of the time. A further prospective test of the automatic scoring system with new data yielded agreement of 96.02%. Finally, the data collection and recording functions were implemented in a wearable microprocessor-based digital activity monitor. The automatic scoring program was adjusted to use activity data collected by this monitor, and agreed 93.88% with EEG scoring. A prospective test with new data agreed 93.04% with EEG. Automatic scoring of activity data for sleep/wake is not only fast and accurate, but allows sleep to be monitored in non-laboratory situations. In addition, the score is objective and reliable, and free of scorer bias and drift.

Computers↗
PubMed1980

Wrist-actigraphic estimation of sleep time.

Using a piezoelectric transducer, wrist activity was recorded simultaneously with electroencephalogram (EEG), electro-oculogram (EOG), and submental electromyogram (EMG) to obtain 102 recordings--39 from hospital patients and 63 from nonpatients. On a minute-to-minute basis, wrist activity alone was used to estimate Sleep Time. Blind independent scoring of the EEG-EOG-EMG records was also done to distinguish Sleep and Wake phases. Results from the two Sleep/Wake estimations agreed for 94.5% of the minutes ((96.3% among nonpatients). Correlations between the two methods were determined for Total Sleep Period (r = 0.90). Total Sleep Time (r = 0.89), Wake After Sleep Onset (r = 0.70), and the number of Midsleep Awakenings (r = 0.25). Correlation coefficients were higher when the 39 patients were excluded from the computations. On the average, the actigraphic method overestimated Sleep Time by 15 min. Continuous wrist activity recordings provide simple and inexpensive, but rather accurate, estimates of sleep duration.

Adolescent↗
PubMed1978

Wrist actigraphic measures of sleep and rhythms.

With a piezo-electric activity transducer, wrist activity recordings were made simultaneously with EEG, EOG and EMG recordings. Wrist activity alone was used to estimate Total Sleep Time and blind independent scoring of sleep and wakefulness by EEG-EOG-EMG was done. Correlations between the two methods were termined for minutes of Sleep (r = 0.98), Total Sleep Period (r = 0.95) and minutes of Wake Time Within Sleep (r = 0.85). Continuous wrist activity recordings may thus provide inexpensive but very accurate estimates of Sleep Time.

Electroencephalography↗
PubMed1978

Circadian rhythm disorders in manic-depressives.

Seven circular manic-depressives were studied through complete of cycles of mania and depression. In five subjects, there was evidence that a circadian rhythm free-ran fast (p less than 0.005 and p less than 0.002 in two of the subjects), and in five subjects, there was evidence that lithium slowed a circadian rhythm. The palliative benefit of lithium may derive from slowing or delaying an overfast circadian clock to prevent desynchronization. Two subjects whose circadian clocks seemed too slow were lithium nonresponders (p less than 0.05). As circadian clock frequency may be transmitted on an X-chromosome gene and may increase with age, a circadian etiology is consistent with the genetics and age distribution of manic-depressive illness. Affective disturbances could be evolutionary remnants of the photo-periodic seasonal responses in animals.

Adult↗