Faculty Bibliography

RATIONALE: Previous studies have shown that sleep-disordered breathing (S

Introduction: Effects of exercise on dynamic aspects of sleep have not been studied. We hypothesized that exercise alters dynamics of sleep stage transitions in healthy controls and patients with chronic fatigue syndrome (CFS). Methods: Sixteen female healthy controls (age: 38+9 years) and 17 female patients with CFS (age: 41+8 years) underwent overnight polysomnography (PSG) on a baseline night and on a night after their performance of a maximal exercise test. All subjects had an adaptation PSG to mitigate any irst night effect. We calculated transition probabilities and rates between sleep stages (waking, rapid eye movement [REM] sleep, N1, N2 and N3) and cumulative duration distributions of each sleep stage and sleep as a whole. Results: After exercise, healthy controls showed a signiicantly greater probability of transition from N1 to N2 and a lower rate of transition from N1 to wake than at baseline; CFS patients showed a signiicantly greater probability of transition from N2 to N3 and a lower rate of transition from N2 to N1. For both groups, these indings suggest there is improved quality of sleep after exercise. Continuity of sleep in the controls improved after exercise, while CFS patients had less continuous N1 and more continuous REM sleep. Despite their improvement in overall quality of sleep after exercise, CFS patients had a signiicantly greater probability and rate of transition from REM to wake compared to healthy controls. Conclusion: Exercise promotes transitions to deeper sleep stages for both healthy controls and CFS patients, but CFS patients showed coexisting sleep disruption and more fatigue. While exercise had positive effects on dynamic sleep morphology in both healthy controls and CFS patients, CFS patients may not fully normalize their sleep with exercise alone

Introduction: During sleep studies, pulse oximetry using forehead relectance (R-ox) may have advantages over transmittance inger oximetry (T-ox) because of its ease of application. R-ox has been shown to be accurate and sensitive overall, but may be more subject to artifact from motion and changes in pressure on the sensor than T-ox. The purpose of the present study was to evaluate the signal loss of these two technologies using two commercially available devices used for home sleep testing of sleep-disordered breathing. Methods: We analyzed consecutive home studies performed in a cohort of 128 subjects (38% M, age 69+8 years, BMI 26.2+5.4kg/m², 267 nights of data) who used the ARES Unicorder (with R-ox) for 1-3 nights as part of a research study and 50 additional subjects (72% M, age 46+12 years, BMI 27.5+5.0kg/m², 50 nights of data) who used a Compumedics Somte (with T-ox) for one night as part of their clinical workup. The oximetry signal for each night was reviewed and oximet ry signal loss (%loss) was tabulated using automated detection followed by manual review. %loss between groups was compared by Mann-Whitney Rank Sum Test and Kolmogorov-Smirnov (KS-test). Results: In R-ox, TIB was 13.6+3.0 hr (over 2 nights); RDI was 24.5+15.2/hr. In T-ox, TIB was 7.6+1.0 hrs (1 night); RDI was 18.9+16.9/ hr. Overall, we could not show a signiicant difference for %loss between the two devices (%loss R-ox vs T-ox: median= 2.2% vs 3.1%; 25th %ile= 0% vs 0%; 75th %=13.7% vs 17.7%, p=ns by both statistical tests). In particular, there was no signiicant difference in the proportion of studies with <10% signal loss ("acceptable") between R-ox and T-ox (66% vs 68%). The two technologies also had similar proportion of studies with >40% signal loss (8% vs 8%). However, in the studies with 10- 40% loss (27% of R-ox and 24% of T-ox) there was signiicantly greater %loss in the R-ox studies (median =20% vs 15%, p=0.02 for rank-sum, p=0.004 KS-test). Conclusion: Overall, our data show equal num!

Introduction: Sleep is important for memory, and various parameters of sleep may affect consolidation of spatial memory speciically. Both hippocampal electrophysiological evidence and behavioral performance evidence support roles for slow wave sleep (SWS) and REM sleep in spatial navigation. The role of REM is of particular clinical interest, as sleep disordered breathing (S

Introduction: Our previous work in cognitively normal elderly shows sleep-disordered breathing (S

STUDY OBJECTIVES: Adherence to CPAP therapy is low in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). The purpose of the present study was to evaluate the utility of measures of sleep architecture and sleep continuity on the CPAP titration study as predictors of both short- and long-term CPAP adherence. METHODS: 93 patients with OSAHS (RDI 42.8 +/- 34.3/h) underwent in-laboratory diagnostic polysomnography, CPAP titration, and follow-up polysomnography (NPSG) on CPAP. Adherence to CPAP was objectively monitored. Short-term (ST) CPAP adherence was averaged over 14 days immediately following the titration study. Long-term (LT) CPAP adherence was obtained in 56/93 patients after approximately 2 months of CPAP use. Patients were grouped into CPAP adherence groups for ST (< 2 h, 2-4 h, and > 4 h) and LT adherence (< 4 h, > 4 h). Sleep architecture, sleep disordered breathing (SDB) indices, and daytime outcome variables from the diagnostic and titration NPSGs were compared between CPAP adherence groups. RESULTS: There was a significant relationship between ST and LT CPAP adherence (r = 0.81, p < 0.001). Neither ST nor LT adherence were related to demographic variables, baseline severity of untreated SDB, sleep architecture, or measures of daytime impairment. Good CPAP adherence groups had significantly lower %N2 and greater %REM on the titration NPSG. A model combining change in sleep efficiency and change in sleep continuity between the diagnostic and titration NPSGs predicted 17% of the variance in LT adherence (p = 0.006). CONCLUSIONS: These findings demonstrate that characteristics of sleep architecture, even on the titration NPSG, may predict some of the variance in CPAP adherence. Better sleep quality on the titration night was related to better CPAP adherence, suggesting that interventions to improve sleep on/prior to the CPAP titration study might be used as a therapeutic intervention to improve CPAP adherence. CITATION: Somiah M; Taxin Z; Keating J; Mooney AM; Norman RG; Rapoport DM; Ayappa I. Sleep quality, short-term and long-term CPAP adherence. J Clin Sleep Med 2012;8(5):489-500.

Rationale: Twenty-eight percent of people with mild to moderate obstructive sleep apnea experience daytime sleepiness, which interferes with daily functioning. It remains unclear whether treatment with continuous positive airway pressure improves daytime function in these patients. Objectives: To evaluate the efficacy of continuous positive airway pressure treatment to improve functional status in sleepy patients with mild and moderate obstructive sleep apnea. Methods: Patients with self-reported daytime sleepiness (Epworth Sleepiness Scale score >10) and an apnea-hypopnea index with 3% desaturation and from 5 to 30 events per hour were randomized to 8 weeks of active or sham continuous positive airway pressure treatment. After the 8-week intervention, participants in the sham arm received 8 weeks of active continuous positive airway pressure treatment. Measurements and Main Results: The Total score on the Functional Outcomes of Sleep Questionnaire was the primary outcome measure. The adjusted mean change in the Total score after the first 8-week intervention was 0.89 for the active group (n = 113) and -0.06 for the placebo group (n = 110) (P = 0.006). The group difference in mean change corresponded to an effect size of 0.41 (95% confidence interval, 0.14-0.67). The mean (SD) improvement in Functional Outcomes of Sleep Questionnaire Total score from the beginning to the end of the crossover phase (n = 91) was 1.73 +/- 2.50 (t[90] = 6.59; P < 0.00001) with an effect size of 0.69. Conclusions: Continuous positive airway pressure treatment improves the functional outcome of sleepy patients with mild and moderate obstructive sleep apnea. Clinical trial registered with www.clinicaltrials.gov (NCT 00127348).

BACKGROUND: The aim of this study was to evaluate nocturia severity and nocturia-related differences in sleep, daytime symptoms and functional performance among patients with stable heart failure (HF). METHODS AND RESULTS: In this cross-sectional observational study, we recruited 173 patients [mean age 60.3 +/- 16.8 years; female n = 60 (35%); mean left ventricular ejection fraction 32 +/- 14.6%] with stable chronic HF from HF disease management programs in the northeastern United States. Participants reported nocturia and completed a 6-minute walk test (6MWT), 1 night of ambulatory polysomnography, and the SF-36 Medical Outcomes Study, Epworth Sleepiness, Pittsburgh Sleep Quality Index, Multidimensional Assessment of Fatigue, and Centers for the Epidemiological Studies of Depression scales. Participants reported 0 (n = 30; 17.3%), 1-2 (n = 87; 50.2%), and >/=3 (n = 56; 32.4%) nightly episodes of nocturia. There were decreases in sleep duration and efficiency, REM and stage 3-4 sleep, physical function, and 6MWT distance and increases in the percentage of wake time after sleep onset, insomnia symptoms, fatigue, and sleepiness across levels of nocturia severity. CONCLUSIONS: Nocturia is common, severe, and closely associated with decrements in sleep and functional performance and increases in fatigue and sleepiness in patients with stable HF.

STUDY OBJECTIVES: Sleep disordered breathing events conceptually separate into "obstructive" and "central" events. Esophageal manometry is the definitive but invasive means of classifying hypopneas. The purpose of this project was to identify noninvasive markers for discriminating high vs. low resistance hypopneas. METHODS: Forty subjects with obstructive or central sleep apnea underwent diagnostic polysomnography with nasal cannula airflow and esophageal manometry; 200% resistance relative to reference breaths was used to define "high" resistance. Noninvasive parameters from 292 randomly selected hypopneas in 20 subjects were analyzed and correlated to resistance. The best parameter and cutoff for predicting high relative resistance was determined and tested prospectively in 2 test sets in the 20 remaining subjects. Test Set A: 15 randomly selected hypopneas in each subject; Test Set B: all hypopneas in 7 subjects. RESULTS: In the development set, prolongation of inspiratory time during the 2 smallest breaths of a hypopnea (T(i)) relative to baseline had the best correlation to high relative resistance. In the Test Set A, relative T(i) > 110% classified obstructive events with sensitivity = 72%, specificity = 77%, PPV = 64%, NPV = 83%. Similar numbers were obtained for classification of hypopneas based on presence of flow limitation (FL) alone. When either relative T(i) or presence of FL were used to define high resistance, sensitivity = 84%, specificity = 74%, PPV = 65%, NPV = 89%. Similar results were obtained for Test Set B. CONCLUSIONS: Relative prolongation of T(i) is a good noninvasive predictor of high/low resistance in a dataset with both FL and NFL hypopneas. Combination of FL and relative T(i) improves this classification. The use of T(i) to separate obstructive and central hypopneas needs to be further tested for clinical utility (outcomes and treatment effects). CITATION: Mooney AM; Abounasr KK; Rapoport DM; Ayappa I. Relative prolongation of inspiratory time predicts high versus low resistance categorization of hypopneas. J Clin Sleep Med 2012;8(2):177-185.