Treatment with continuous positive airway pressure is not effective in patients with sleep apnea but no daytime sleepiness. a randomized, controlled trial

BACKGROUND: The sleep apnea-hypopnea syndrome is defined by a pathologic number of respiratory events during sleep (the apnea-hypopnea index, defined as the number of apnea and hypopnea episodes per hour) and daytime symptoms (mostly, excessive sleepiness). In patients with the sleep apnea syndrome, treatment with continuous positive airway pressure (CPAP) normalizes both the apnea-hypopnea index and diurnal symptoms. However, the effect of CPAP in persons with a pathologic apnea-hypopnea index without daytime sleepiness is unclear. OBJECTIVE: To investigate the short-term effects of CPAP on quality of life, objective sleepiness, cognitive function, and arterial blood pressure in nonsleepy patients with a pathologic apnea-hypopnea index. DESIGN: Multicenter randomized, placebo-controlled, parallel-group study. SETTING: Six teaching hospitals in Spain. PATIENTS: 55 patients with an apnea-hypopnea index of 30 or greater who did not have daytime sleepiness (Epworth Sleepiness Scale score 相似文献   

A randomized controlled trial of continuous positive airway pressure in mild obstructive sleep apnea

A common clinical dilemma faced by sleep physicians is in deciding the level of severity at which patients with obstructive sleep apnea (OSA) should be treated. There is particular uncertainty about the need for, and the effectiveness of, treatment in mild cases. To help define the role of nasal continuous positive airway pressure (CPAP) treatment in mild OSA we undertook a randomized controlled cross-over trial of CPAP in patients with an apnea- hypopnea index (AHI) of 5 - 30 (mean, 12.9 +/- 6.3 SD). Twenty-four-hour blood pressure and neurobehavioral function were measured at baseline, after 8 wk of treatment with CPAP, and after 8 wk of treatment with an oral placebo tablet. Twenty-eight of 42 patients enrolled in the study completed both treatment arms. Baseline characteristics were not different between those who completed the study and those who did not complete the study. Patients used CPAP for a mean (SD) of 3.53 (2.13) h per night and the mean AHI on the night of CPAP implementation was 4.24 (2.9). Nasal CPAP improved self-reported symptoms of OSA, including snoring, restless sleep, daytime sleepiness, and irritability (in-house questionnaire), more than did placebo, but did not improve objective (Multiple Sleep Latency Test) or subjective (Epworth Sleepiness Scale) measures of daytime sleepiness. We found no benefit of CPAP over placebo in any tests of neurobehavioral function, generic SF-36 (36-item Short Form Medical Outcomes Survey) or sleep-specific (Functional Outcomes of Sleep Questionnaire) quality of life questionnaires, mood score (Profile of Moods States and Beck Depression Index), or 24-h blood pressure. However, the placebo tablet resulted in a significant improvement in a wide range of functional variables compared with baseline. This placebo effect may account for some of the treatment responses to CPAP observed previously in patients with mild OSA.     

The effect of short-term nasal CPAP on Cheyne-Stokes respiration in congestive heart failure.

We studied male patients (BMI = 27.6 +/- 3.4, mean +/- SD), mean age 54.1 +/- 8.9 years, with stable NYHA class 3-4 congestive heart failure (CHF) (LVEF = 24.3 +/- 11.5 percent) and normal daytime arterial blood gas values. These patients underwent three consecutive nights of full polysomnography; adaptation, control, and treatment with nasal CPAP. Each night's study was followed during the day by cognitive testing and multiple sleep latency tests (MSLT). The purpose of the study was to document the effect of nasal CPAP on these variables. The main findings of the study showed no significant differences between control and treatment nights with respect to the amount of Cheyne-Stokes respiration (CSR) observed, the nocturnal oxygenation, or sleep quality. Both subjective and objective measures of sleep quality showed no change from night to night. In addition, the degree of cognitive functioning and daytime sleepiness (as measured by MSLT) showed no significant differences between control and treatment nights. We conclude that short-term treatment with nasal CPAP in patients with CHF does not improve either CSR, nocturnal oxygenation, or sleep quality. Furthermore, most of our patients did not tolerate nasal CPAP therapy.     

Can patients with obstructive sleep apnea titrate their own continuous positive airway pressure?

Manual continuous positive airway pressure (CPAP) titration in a sleep laboratory is costly and limits access for diagnostic studies. Many factors affect CPAP compliance, but education and support, rather than in-laboratory CPAP titration, appear to be pivotal. Self-adjustment of CPAP at home will provide equal or superior efficacy in the treatment of obstructive sleep apnea (OSA) as compared with in-laboratory titration. A randomized, single-blind, two-period crossover trial of CPAP treatment at the in-laboratory-determined optimal pressure versus at-home self-adjustment of CPAP (starting pressure based on prediction equation). Eighteen CPAP-naive patients (16 males, 50 +/- 15 years old, apnea hypopnea index 40 +/- 20) with a new diagnosis of OSA were tested. Testing was performed before and after CPAP treatment in each of two 5-week study limbs. CPAP, compliance with CPAP treatment, the Sleep Apnea Quality of Life Index, the Functional Outcomes of Sleep Questionnaire score, the Epworth sleepiness scale score, sleep architecture, sleep apnea severity, and maintenance of wakefulness tests were performed. Both modes of CPAP treatment significantly improved objective and subjective measures of OSA, but they did not differ in efficacy. Home self-titration of CPAP is as effective as in-laboratory manual titration in the management of patients with OSA.     

Sleepiness and sleep in patients with both systolic heart failure and obstructive sleep apnea

BACKGROUND: Adverse effects of obstructive sleep apnea (OSA), including sleep deprivation, can contribute to the progression of heart failure. The usual indication to diagnose and treat sleep apnea is subjective sleepiness. Previous studies suggest that patients with both heart failure and obstructive sleep apnea often do not complain of sleepiness, albeit their sleep time may be reduced. Therefore, we tested the hypothesis that patients with heart failure have less sleepiness and sleep less compared with subjects without heart failure for a given severity of OSA. METHODS: Sleepiness assessed with the Epworth Sleepiness Scale and sleep structure measured with polysomnography were compared among 155 consecutive patients with heart failure and from a random community sample (n = 1139) according to categories of the apnea-hypopnea index (<5, no OSA; 5-14, mild OSA; and > or =15, moderate to severe OSA). RESULTS: Compared with the community sample, for any given severity of OSA, patients with heart failure had lower mean +/- SE Epworth Sleepiness Scale scores (7.1 +/- 0.4 vs 8.3 +/- 0.2 [P = .005]; 6.7 +/- 0.7 vs 9.2 +/- 0.3 [P < .001]; and 7.8 +/- 0.7 vs 9.8 +/- 0.4 [P = .01]), indicating less sleepiness despite sleeping less (total sleep time mean +/- SE [in minutes]: 306 +/- 7 vs 384 +/- 2, 295 +/- 19 vs 384 +/- 5, and 285 +/- 13 vs 359 +/- 7 for no, mild, and moderate to severe OSA, respectively; P < .001 for all comparisons). CONCLUSIONS: Patients with heart failure have less subjective daytime sleepiness compared with individuals from a community sample, despite significantly reduced sleep time, whether or not they have OSA. In patients with heart failure, the absence of subjective sleepiness is not a reliable means of ruling out OSA.     

Continuous positive airway pressure reduces subjective daytime sleepiness in patients with mild to moderate Alzheimer's disease with sleep disordered breathing

OBJECTIVES: Studies have reported that 33% to 70% of patients with Alzheimer's disease (AD) have sleep-disordered breathing (SDB). Continuous positive airway pressure (CPAP) treatment has been shown to reduce daytime sleepiness and improve health-related quality of life in nondemented older people with SDB. The effect of therapeutic CPAP treatment on daytime sleepiness in patients with mild-moderate AD with SDB was assessed. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Patients' home and the University of California San Diego, General Clinical Research Center, J. Christian Gillin Laboratory of Sleep and Chronobiology. PARTICIPANTS: Thirty-nine community-dwelling elderly patients with mild-moderate probable AD with SDB. INTERVENTION: Patients were randomly assigned to receive 6 weeks of therapeutic CPAP or 3 weeks of sham CPAP followed by 3 weeks of therapeutic CPAP. MEASUREMENTS: Epworth Sleepiness Scale (ESS) was administered at baseline, 3 weeks, and 6 weeks. Changes in daytime sleepiness in subjects who received optimal therapeutic CPAP were compared with changes in the sham CPAP group. RESULTS: Within the therapeutic CPAP group, ESS scores were reduced from 8.89 during baseline to 6.56 after 3 weeks of treatment (P=.04) and to 5.53 after 6 weeks of treatment (P=.004). In the sham CPAP group, there was no significant difference after 3 weeks of sham CPAP but a significant decrease from 7.68 to 6.47 (P=.01) after 3 weeks of therapeutic CPAP. CONCLUSION: These data provide evidence of the effectiveness of CPAP in reducing subjective daytime sleepiness in patients with AD with SDB.     

Continuous positive airway pressure improves nocturnal baroreflex sensitivity of patients with heart failure and obstructive sleep apnea

OBJECTIVES: To determine the acute effects of continuous positive airway pressure (CPAP) on baroreceptor reflex sensitivity (BRS) for heart rate during sleep in congestive heart failure (CHF) patients with obstructive sleep apnea (OSA). DESIGN AND METHODS: In eight CHF patients with OSA not previously treated with CPAP, spontaneous BRS was assessed during overnight polysomnography prior to the onset of sleep, and during stage 2 non-rapid eye movement sleep (NREM) before, during and after application of CPAP. RESULTS: CPAP alleviated OSA and acutely increased the slope of BRS (median, 25%,75%) [from 3.9 (3.5, 4.8) to 6.2 (4.6, 26.2) ms/mmHg, P<0.05]. Increases in the slope of BRS persisted following withdrawal of CPAP [4.9 (4.3, 6.9) ms/mmHg, P<0.05]. CPAP also lowered heart rate (from 81.3 +/- 4.9 to 76.0 +/- 5.7 bpm, P< 0.05), an effect which persisted after its withdrawal (76.7 +/- 5.7 bpm, P < 0.05). Systolic blood pressure at the midpoint of the pressure range of BRS sequences fell while on CPAP (from 139 +/- 8 to 120 +/- 7 mmHg, P < 0.05), and remained lower following CPAP withdrawal (124 +/- 9 mmHg, P < 0.05). CONCLUSIONS: In CHF patients with OSA, CPAP increases acutely BRS during sleep, lowers heart rate and resets the operating point for BRS to a lower blood pressure. These effects of CPAP persist after its withdrawal, suggesting that nocturnal CPAP therapy may cause sustained improvement in the neural control of heart rate.     

Polysomnography before and after weight loss in obese patients with severe sleep apnea

OBJECTIVE: While obstructive sleep apnea (OSA) is strongly related to obesity, few studies have examined polysomnographic (PSG) changes with major weight loss. We examined the effect of weight loss following laparoscopic adjustable gastric banding (LAGB) on the PSG changes in patients with severe OSA. In addition, we studied daytime sleepiness, the metabolic syndrome and quality of life (QOL). METHODS: A prospective study was conducted of 25 severely obese patients (17 men, eight women) with paired diagnostic PSG, biochemical and questionnaire studies, the first prior to LAGB and the second at least 1 y later. Subjects with a baseline apnea-hypopnea index (AHI) >25/h were included. RESULTS: Subject baseline age was 44.7 y, weight 154 kg and body mass index 52.7 kg/m(2). The second PSG study was conducted 17.7+/-10 (range 12-42) months after surgery and mean percentage of excess loss and weight loss were 50.1+/-15% (range 24-80%) and 44.9+/-22 kg (range 18-103 kg), respectively. There was a significant fall in AHI from 61.6+/-34 to 13.4+/-13, improved sleep architecture with increased REM and stage III and IV sleep, daytime sleepiness, as measured by Epworth Sleepiness Scale, of 13+/-7.0 to 3.8+/-3.0, and fewer patients requiring nasal continuous positive airways pressure (CPAP). There were also major improvements in the metabolic syndrome, QOL, body image and fewer symptoms of depression (P<0.05 for all). CONCLUSION: Weight loss provides major improvement or resolution of OSA and CPAP requirements. It also reduces daytime sleepiness, and improves the metabolic syndrome and QOL. LAGB placement should be considered a broadly effective therapy for sleep apnea in the severely obese patient.     

Controlled trial of continuous positive airway pressure in obstructive sleep apnea and heart failure

Obstructive sleep apnea (OSA) is highly prevalent among patients with congestive heart failure (CHF) and may contribute to progression of cardiac dysfunction via hypoxia, elevated sympathetic nervous system activity, and systemic hypertension. Our aim was to assess the long-term effect of OSA treatment with nocturnal continuous positive airway pressure (CPAP) on systolic heart function, sympathetic activity, blood pressure, and quality of life in patients with CHF. Fifty-five patients with CHF and OSA were randomized to 3 months of CPAP or control groups. End points were changes in left ventricular ejection fraction, overnight urinary norepinephrine excretion, blood pressure, and quality of life. Nineteen patients in the CPAP group and 21 control subjects completed the study. Compared with the control group, CPAP treatment was associated with significant improvements in left ventricular ejection fraction (delta 1.5 +/- 1.4% vs. 5.0 +/- 1.0%, respectively, p = 0.04), reductions in overnight urinary norepinephrine excretion (delta 1.6 +/- 3.7 vs. -9.9 +/- 3.6 nmol/mmol creatinine, p = 0.036), and improvements in quality of life. There were no significant changes in systemic blood pressure. In conclusion, treatment of OSA among patients with CHF leads to improvement in cardiac function, sympathetic activity, and quality of life.     

An auto-continuous positive airway pressure device controlled exclusively by the forced oscillation technique.

The forced oscillation technique (FOT) has been demonstrated to be a very sensitive tool for the assessment of upper airway obstruction during nasal continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea (OSA). The present study was designed to evaluate the therapeutic efficacy of a novel auto-CPAP device based exclusively on the FOT. Following manual CPAP titration, 18 patients with OSA (mean apnoea/hypopnoea index (AHI) 48.0+/-28.1) were allocated to conventional CPAP and auto-CPAP treatment under polysomnographic control in randomized order. The patients were asked to assess their subjective daytime sleepiness using the Epworth Sleepiness Scale (ESS). The mean AHI during auto-CPAP treatment was 3.4+/-3.4 and was comparable with that obtained during conventional CPAP treatment (4.2+/-3.6). The analysis of sleep architecture, the arousal index (6.6+/-2.1 versus 7.3+/-4.4) or the ESS (5.6+/-1.8 versus 7.3+/-4.4) did not reveal any significant differences. However, the mean CPAP pressure during auto-CPAP treatment (0.84+/-0.26 kPa) and in particular the pressure applied in the lateral body position (0.74+/-0.35 kPa), was significantly lower than that employed in conventional CPAP treatment (0.93+/-0.16 kPa, both comparisons: p<0.05). The auto-continuous positive airway pressure device proved equally as effective as conventional continuous positive airway pressure. However, the mean treatment pressure was significantly reduced, especially when patients were sleeping in the lateral position.     

Inhibition of awake sympathetic nerve activity of heart failure patients with obstructive sleep apnea by nocturnal continuous positive airway pressure

OBJECTIVES: This study was designed to determine whether reductions in morning systolic blood pressure (BP) elicited by treatment of moderate to severe obstructive sleep apnea (OSA) in heart failure (HF) patients are associated with a reduction in sympathetic vasoconstrictor tone. BACKGROUND: Daytime muscle sympathetic nerve activity (MSNA) is elevated in HF patients with coexisting OSA. In our recent randomized trial in HF, abolition of OSA by continuous positive airway pressure (CPAP) increased left ventricular ejection fraction (LVEF) and lowered morning systolic BP. METHODS: Muscle sympathetic nerve activity, BP, and heart rate (HR) of medically treated HF patients (EF <45%) and OSA (apnea-hypopnea index > or =20/h of sleep) were recorded on the morning after overnight polysomnography, and again one month after patients were randomly allocated nocturnal CPAP treatment or no CPAP (control). RESULTS: In nine control patients, there were no significant changes in the severity of OSA, MSNA, systolic BP, or HR. In contrast, in the 8 CPAP-treated patients, OSA was attenuated, and there were significant reductions in daytime MSNA (from 58 +/- 4 bursts/min to 48 +/- 5 bursts/min; 84 +/- 4 bursts/100 heart beats to 72 +/- 5 bursts/100 heart beats; p < 0.001 and p = 0.003, respectively), systolic BP (from 135 +/- 5 mm Hg to 120 +/- 6 mm Hg, p = 0.03), and HR (from 69 +/- 2 min(-1) to 66 +/- 2 min(-1); p = 0.013). CONCLUSIONS: Treatment of coexisting OSA by CPAP in HF patients lowers daytime MSNA, systolic BP, and HR. Inhibition of increased central sympathetic vasoconstrictor outflow is one mechanism by which nocturnal CPAP reduces awake BP in HF patients with moderate to severe OSA.     

Continuous positive airway pressure therapy for treating sleepiness in a diverse population with obstructive sleep apnea: results of a meta-analysis

BACKGROUND: Although continuous positive airway pressure (CPAP) has become the standard of care in the treatment of obstructive sleep apnea (OSA), 2 systematic reviews have questioned its utility. Since the publication of these reviews, several randomized controlled trials have been reported. We, therefore, performed a meta-analysis to assess the effect of CPAP on subjective and objective sleepiness. METHODS: We conducted a thorough literature search to identify all published randomized controlled trials of CPAP in patients with OSA. Meta-analyses were performed using a random-effects model. Statistical heterogeneity was assessed using the Q statistic. RESULTS: Twelve trials of CPAP in patients with OSA meeting our inclusion criteria were found. The Epworth Sleepiness Scale score was reported in 11 studies (706 patients). A meta-analysis found that CPAP reduced the Epworth Sleepiness Scale score an average of 2.94 points more than placebo (P<.001). The heterogeneity (Q10 = 57.7, P<.001) between studies could not be explained by differences in sex composition, mean age, mean body mass index, or country of study. Trials recruiting subjects with severe OSA plus sleepiness (mean apnea-hypopnea index, > or =30 events per hour; and mean Epworth Sleepiness Scale score, > or =11) had a greater decrease in the Epworth Sleepiness Scale score than the other studies (4.75 vs 1.10; P<.001). Objective measures of sleepiness were reported in 8 trials (482 subjects). Continuous positive airway pressure increased sleep onset latency by 0.93 minute (P =.04) more than placebo. CONCLUSIONS: Continuous positive airway pressure therapy significantly improves subjective and objective measures of sleepiness in patients with OSA across a diverse range of populations. Patients with more severe apnea and sleepiness seem to benefit the most.     

Long-term compliance with nasal continuous positive airway pressure therapy of obstructive sleep apnea

In an attempt to identify predictors of long-term compliance with nasal continuous positive airway pressure (CPAP), we reviewed the records of 125 patients with obstructive sleep apnea (OSA) referred to our center for nasal CPAP trials. Severity of sleep apnea, sleep staging, daytime hypersomnolence, effectiveness of nasal CPAP, previous palatal surgery, and adverse reactions were compared in compliant and noncompliant patients. Nineteen patients did not tolerate a nasal CPAP trial in the laboratory or refused home nasal CPAP therapy. Ten patients were unavailable for follow-up. Of the remaining 96 patients, 23 (24 percent) had discontinued therapy, while 73 (76 percent) were still using nasal CPAP at 14.5 +/- 10.7 months (mean +/- SD). There were no statistically significant differences between the compliant and noncompliant patients in baseline apnea plus hypopnea index (AHI), baseline sleep staging, AHI while receiving nasal CPAP, sleep staging while receiving nasal CPAP, or frequency of adverse reactions during therapy. Severe daytime sleepiness was present in 65 of the 73 compliant patients and in 12 of the 23 noncompliant patients (p less than 0.05). Ten of 43 in the compliant group had previous palatal surgery compared with ten of 23 noncompliant patients (p less than 0.05). Our data confirm earlier observations in smaller samples that compliant and noncompliant patients have equally severe sleep apnea and good initial responses to nasal CPAP. Long-term compliance with nasal CPAP may be associated with the severity of daytime hypersomnolence on presentation. Previous palatal surgery was more frequent in patients who did not tolerate long-term nasal CPAP therapy.     

Daytime pulmonary hypertension in patients with obstructive sleep apnea: the effect of continuous positive airway pressure on pulmonary hemodynamics.

BACKGROUND: Limited information exists regarding the development of pulmonary hypertension in patients with obstructive sleep apnea (OSA) in the absence of lung and heart comorbidity. OBJECTIVES: The aims of this study were to investigate whether OSA patients without any other cardiac or lung disease develop pulmonary hypertension, and to assess the effect of continuous positive airway pressure (CPAP) treatment on pulmonary artery pressure (P(PA)). METHODS: Twenty-nine patients aged 51 +/- 10 years with OSA and 12 control subjects were studied with pulsed-wave Doppler echocardiography for estimation of P(PA) before and after 6-month effective treatment with CPAP. RESULTS: A significantly higher mean P(PA) was found in OSA patients as compared to control subjects (17.2 +/- 5.2 vs. 12.1 +/- 1.9 mm Hg, p < 0.001). Six out of the 29 OSA patients had mild pulmonary hypertension (P(PA) > or = 20 mm Hg). Significant differences were observed between pulmonary hypertensive and normotensive OSA patients with respect to age (62 +/- 4 vs. 48 +/- 15 years, respectively, p < 0.05), body mass index (41 +/- 7 vs. 32 +/- 4 kg/m(2), p < 0.02) and daytime P(a)O(2) (81 +/- 9 vs. 92 +/- 9 mm Hg, p < 0.05). CPAP treatment was effective in reducing mean P(PA) in both groups of pulmonary hypertensive and normotensive OSA patients (decreases in P(PA) from 25.6 +/- 4.0 to 19.5 +/- 1.5 mm Hg, p < 0.001; from 14.9 +/- 2.2 to 11.5 +/- 2.0 mm Hg, respectively, p < 0.001). CONCLUSIONS: A proportion (20.7%) of OSA patients without any other lung or heart disease and characterized by older age, greater obesity and lower daytime oxygenation develop mild pulmonary hypertension which has been partially or completely reversed after 6-month CPAP treatment. In conclusion, OSA alone constitutes an independent risk factor for the development of pulmonary hypertension.     

Nocturnal pulse rate and symptomatic response in patients with obstructive sleep apnoea treated with continuous positive airway pressure for one year

Background

Obstructive sleep apnoea (OSA) is the most common form of sleep-disordered breathing and a known risk factor for cardiovascular disease. We hypothesised that in patients with OSA the characteristics of nocturnal pulse rate (PR) are associated with changes in blood pressure and daytime sleepiness, following commencement of continuous positive airway pressure (CPAP) therapy.

Methods

Pulse oximetry data, demographics, daytime sleepiness and blood pressure were recorded at baseline and at one year follow up. Patients with OSA were grouped according to positive and negative changes in the PR (ΔPR) response during the first night of pulse oximetry before commencement of CPAP.

Results

A total of 115 patients (58 with OSA and 57 matched subjects without OSA) were identified and included in the analysis. The scale of improvement in daytime sleepiness could be predicted by a negative or positive ΔPR, as recorded in the initial screening pulse oximetry [ΔESS –5.8 (5.1) vs. –0.8 (7.2) points, P<0.05]. A negative correlation was observed between mean nocturnal PR and changes in systolic blood pressure (SBP) after one year of CPAP treatment (r=–0.42, P<0.05).

Conclusions

Mean nocturnal PR prior to CPAP initiation was associated with changes in SBP at one year follow up. A descending nocturnal PR in patients with OSA, prior to CPAP initiation, might help to identify a symptomatic response from long term CPAP treatment.     

Symptom burden of sleep-disordered breathing in mild-to-moderate congestive heart failure patients.

The symptom burden resulting from sleep-disordered breathing (SDB) in patients with mild-to-moderate congestive heart failure (CHF) is unclear. The current authors monitored 24-h activity levels and compared subjective and objective measures of daytime sleepiness in 39 CHF patients, New York Heart Association class 2-3, on optimal medication. A total of 22 patients were classified as SDB (apnoea/hypopnoea index (AHI) median (range) 22.3 (16.6-100) events.h-1), and 17 as no SDB (NoSDB; AHI 3.7 (0-12.3) events.h-1). SDB was defined as AHI>or=15 events.h-1. Patients were assessed by 24-h activity monitoring (actigraphy) for a period of up to 14 days, a single objective sleepiness test (Oxford Sleep Resistance test) and Epworth Sleepiness Scale. The duration of daytime activity was significantly shorter in the SDB group compared with the NoSDB group. The SDB group also had increased time in bed and poorer sleep quality, as shown by the fragmentation index. Objectively the SDB group when compared with the NoSDB group were significantly sleepier, subjectively the groups did not differ. The amount of napping was similar for both groups. Despite the lack of subjective symptoms of daytime sleepiness, congestive heart failure patients with sleep-disordered breathing were objectively sleepier during the day and had reduced daytime activity with longer periods in bed and poorer sleep quality when compared with those without sleep-disordered breathing.     

Pharmacologic approaches for the management of symptoms and cardiovascular consequences of obstructive sleep apnea in adults

Introduction

Obstructive sleep apnea (OSA) is characterized by intermittent hypoxemia, arousals from sleep, and daytime sleepiness. Accumulating evidence indicates that hypoxemia and sleep disruption contribute to the development of cardiovascular abnormalities in OSA. OSA is effectively treated with continuous positive airway pressure (CPAP) therapy that splints open the airway during sleep. Studies have shown that CPAP therapy improves daytime sleepiness and attenuates cardiovascular abnormalities in patients with OSA. However, not all patients with OSA tolerate or adhere to CPAP therapy. Even patients who regularly use CPAP therapy may have a few hours each night exposed to the negative effects of untreated OSA. As a result, complementary pharmacologic therapies that can be used with CPAP therapy have the potential to reduce symptoms and consequences of OSA.

Discussion

The wake-promoting medications modafinil and armodafinil effectively improve residual sleepiness in patients treated with CPAP therapy. Although results are equivocal so far, modafinil and armodafinil may also improve quality of life and global clinical condition in patients with OSA and residual sleepiness treated with CPAP therapy. Pharmacologic therapies also have the potential to be used with CPAP therapy to minimize cardiovascular perturbations and risk of cardiovascular disease. Preliminary studies suggest that inhibition of the enzyme xanthine oxidase and inhibition of sympathetic nervous system overactivity may have therapeutic potential to reduce cardiovascular harm in patients with OSA.

Conclusion

Future studies of pharmacologic therapies to reduce symptoms and cardiovascular consequences of OSA should be increasingly performed as our understanding of the mechanisms mediating the adverse effects of OSA continues to evolve.     

Oral appliance therapy improves symptoms in obstructive sleep apnea: a randomized,controlled trial

The aim of this study was to evaluate the effect of a mandibular advancement splint (MAS) on daytime sleepiness and a range of other symptoms in obstructive sleep apnea (OSA). Using a randomized crossover design, patients received 4 weeks of treatment with MAS and a control device (inactive oral appliance), with an intervening 1-week washout. At the end of each treatment period, patients were reassessed by questionnaire, polysomnography, and multiple sleep latency test. Fifty-nine men and 14 women with a mean (+/- SD) age of 48 +/- 11 years and proven OSA experienced a significantly improved mean (+/- SEM) sleep latency on the multiple sleep latency test (10.3 +/- 0.5 versus 9.1 +/- 0.5 minutes, p = 0.01) and Epworth sleepiness scale score (7 +/- 1 versus 9 +/- 1, p < 0.0001) with the MAS compared with the control device after 4 weeks. The proportion of patients with normal subjective sleepiness was significantly higher with the MAS than with the control device (82 versus 62%, p < 0.01), but this was not so for objective sleepiness (48 versus 34%, p = 0.08). Other OSA symptoms were controlled in significantly more patients with the MAS than with the control device. MAS therapy improves a range of symptoms associated with OSA.     

Pulmonary hypertension in obstructive sleep apnoea: effects of continuous positive airway pressure: a randomized, controlled cross-over study.

AIMS: We tested the hypothesis that: (i) obstructive sleep apnoea (OSA) by itself originates pulmonary hypertension (PH); and (ii) the application of continuous positive airway pressure (CPAP) can reduce pulmonary pressure. METHODS AND RESULTS: In this randomized and cross-over trial, 23 middle-aged OSA (apnoea-hypopnoea index, 44.1 +/- 29.3 h(-1)) and otherwise healthy patients and 10 control subjects were included. OSA patients randomly received either sham or effective CPAP for 12 weeks. Echocardiographic parameters, blood pressure recordings, and urinary catecholamine levels were obtained at baseline and after both treatment modalities. At baseline, OSA patients had higher pulmonary artery systolic pressure than control subjects (29.8 +/- 8.8 vs. 23.4 +/- 4.1 mmHg, respectively, P = 0.036). Ten out of 23 patients [43%, (95% CI: 23-64%)] and none of the control subjects had PH at baseline (P = 0.012). Two patients were removed from the study because of inadequate CPAP compliance. Effective CPAP induced a significant reduction in the values for pulmonary systolic pressure (from 28.9 +/- 8.6 to 24.0 +/- 5.8 mmHg, P < 0.0001). The reduction was greatest in patients with either PH or left ventricular diastolic dysfunction at baseline. CONCLUSION: Severe OSA is independently associated with PH in direct relationship with disease severity and presence of diastolic dysfunction. Application of CPAP reduces pulmonary systolic pressure levels.