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Biomedical subjects

S L Noe

Publications and source records attributed to S L Noe.

4 recordsLinked to original sources

Daytime functioning in obstructive sleep apnea patients: exercise tolerance, subjective fatigue, and sleepiness.

A sample of 32 obstructive sleep apnea patients (27 males, 5 females) was assessed with overnight polysomnography and the Multiple Sleep Latency Test (MSLT), an objective measure of daytime sleepiness. Patients also participated in a maximal exercise test, which served as an objective indicator of physical fatigue. The Fatigue Severity Scale (FSS) was used as a subjective measure of fatigue. Subjective fatigue ratings were significantly correlated with percent of predicted maximum heart rate achieved during exercise testing, suggesting that self-reported fatigue in apnea patients may refer to reduced physical fitness. FSS scores and exercise testing results were not significantly correlated with the MSLT, indicating that daytime fatigue and daytime sleepiness are independent problems in apnea patients. Participants self-reported a high level of fatigue, and exercise testing revealed decreased physical work capacity among apnea patients, but objective and subjective indicators of fatigue were not significantly correlated with apnea severity. A higher percentage of REM sleep predicted greater work capacity.

Adult↗

Fatigue and sleep disorders.

Fatigue has often been confused with sleepiness and has received little study as an independent symptom of sleep disturbance. To investigate if fatigue is a common and severe symptom in sleep disordered individuals, the Fatigue Severity Scale (FSS) was administered to 206 patients over a 12-month period at a sleep disorder center. Our sample averaged 4.8 on the 7-point FSS, which is in the severe fatigue range. High fatigue was present in a broad range of sleep disorders, but was particularly high among individuals diagnosed with psychophysiological insomnia. A number of variables predicted fatigue (being female, being a smoker, high BMI, low sleep efficiency percent, and high MMPI average clinical scale score), but surprisingly daytime sleepiness (as measured by the multiple sleep latency test) did not. Apparently, daytime sleepiness and perceived fatigue are independent phenomena. We discussed the importance of attributing credence to the complaint of fatigue and suggested some areas for future study including further study of fatigue in insomnia, expanded consideration of sleep variables causing fatigue, and testing objective measures of fatigue.

Adolescent↗

Intensity pattern of snoring sounds as a predictor for sleep-disordered breathing.

The relationship between a new operational definition of sleep sounds and apnea was examined in a population of 69 patients referred for overnight evaluations in a sleep disorders center. The sample contained 18 women (mean age 53.6 years) and 51 men (mean age 48.4 years). Subjects underwent polysomnography (PSG) with concurrent graphical recording of sleep sound intensities throughout the night. An acoustical signature event (ASE) was defined as a loud sound preceded by at least 10 but no more than 90 seconds of silence. Multiple regression was performed using known correlates of apnea and ASE to predict PSG levels of respiratory disturbance. Of the commonly known correlates, only self-reported estimate of snoring and apnea severity explained significant variance to the respiratory disturbance index (RDI; R2 = 0.24, p < 0.0001). ASE was entered into the equation as the last step, significantly improving explained variance (R2delta = 0.54, p < 0.0001). The final equation R2 was 78% (p < 0.0001). An alternative analysis compared ASE findings to polysomnographic findings in each matched 30-second interval (60,231 observations) in an analysis of receiver's operating characteristics. This analysis resulted in d' = 2.67, indicating acceptable accuracy for screening.

Adult↗

Daytime sleepiness in insomnia: behavioral, biological and subjective indices.

We compared three measures of daytime sleepiness, sleep behavior (as measured by the multiple sleep latency test), a biological index of sleepiness (pupillometry) and subjective sleepiness (as measured by the Stanford Sleepiness Scale), in evaluating middle-aged individuals with psychophysiological insomnia (n = 20) or no sleep problem (n = 20). Subjects underwent polysomnography (PSG) and four multiple sleep latency test/pupillometry trials the following day. The results determined that neither behavioral, biological nor subjective indices distinguished these two groups. Differentiating the insomniacs into true insomniac (n = 14) and normal sleeping insomniac (insomniacs with sleep efficiency greater than 90%, n = 6) subgroups based upon PSG did not improve daytime discriminations. Furthermore, nighttime sleep experience, measured by either PSG or self-report, was not a strong predictor of these daytime indices among either insomniacs or noninsomniacs. The results of this study support the conclusions that insomniacs do not exhibit heightened levels of daytime sleepiness and that routine fluctuations in sleep exert minimal influence on daytime sleepiness among insomniacs and noninsomniacs. The former finding is likely due either to insomniacs satisfying their biological sleep need despite poor sleep or chronic physiological hyperarousal preventing both sleep and sleepiness.

Adult↗