The impact of intranasal corticosteroids in a prospective cohort of children with sleep disordered breathing

INTRODUCTION

Sleep disordered breathing (SDB) is common in children and the most common reason for adenotonsillectomy. This large observational cohort study from a specialist outpatient clinic describes the impact of intranasal steroids (INS) on symptom improvement and the need for surgery.

METHOD

Observational cohort study of 568 children assessing the impact of INS using the OSA-5 questionnaire with clinical and surgical outcome measures.

RESULTS

The mean OSA-5 score at first visit was 7.78. Symptoms were persistent for a median 9 months (range 2-72). 51% underwent a trial of INS with 56% reporting symptomatic improvement. The mean score decreased from 8.2 to 5.5 (p < 0.0001) in those prescribed INS. They had a significantly higher symptom load (p < 0.01), turbinate size (p < 0.005) and history of atopy (p < 0.01) than the non-trial group. The rate of surgery in the non-trial group was 56% compared with 38% in those who had INS (p < 0.001). With increasing symptom burden, the reported improvement with INS and comparative reduction in surgery increased. Baseline OSA-5 scores were predictive of rates of surgery. Atopic status or age did not influence response to INS.

CONCLUSION

The mean score at first visit and the median duration of symptoms indicated significant persistent symptoms in this cohort. The use of INS improved symptoms of SDB in 56%. The need for surgery in the group that received INS was 38% compared with 56% in those not trialling INS, despite the non-trial group having significantly less symptoms and signs. Symptomatic improvement was not influenced by age or atopic status.

[Sleep-Disordered Breathing at High Altitude: Its Characteristics and Research Progress in Treatment]

Hypobaric hypoxia in regions of high altitude may increase the risk of having sleep-disordered breathing (SDB). SDB at high altitude mainly refers to the SDB incurred in highlanders and lowlanders at a high altitude. At present, research on SDB at high altitude is mainly focused on these two groups of people. On the one hand, highlanders have SDB at a higher prevalence and greater severity than lowlanders do and highlanders have a prolonged duration of apnea when they travel to low-altitude regions. On the other hand, the severity of SDB increased in lowlanders when they travel to high altitude, represented mainly by an increase in central and hypopnea events. In terms of treatment, a substantial number of studies have shown that medication, including acetazolamide and dexamethasone, and nocturnal oxygen supplementation could improve SDB in lowlanders when they travel to high altitude. However, not much research has been done on the treatment of SDB in highlanders and it has only been reported that nocturnal oxygen supplementation was an available treatment option. Herein, we summarized the latest research findings on SDB at high altitude, providing the basis for further studies about the characteristics and treatments for highlanders with SDB.

Opioids and obstructive sleep apnea

Opioids are widely prescribed for pain management, and it is estimated that 40% of adults in the United States use prescription opioids every year. Opioid misuse leads to high mortality, with respiratory depression as the main cause of death. Animal and human studies indicate that opioid use may lead to sleep-disordered breathing. Opioids affect control of breathing and impair upper airway function, causing central apneas, upper airway obstruction, and hypoxemia during sleep. The presence of obstructive sleep apnea (OSA) increases the risk of opioid-induced respiratory depression. However, even if the relationship between opioids and central sleep apnea is firmly established, the question of whether opioids can aggravate OSA remains unanswered. While several reports have shown a high prevalence of OSA and nocturnal hypoxemia in patients receiving a high dose of opioids, other studies did not find a correlation between opioid use and obstructive events. These differences can be attributed to considerable interindividual variability, divergent effects of opioids on different phenotypic traits of OSA, and wide-ranging methodology. This review will discuss mechanistic insights into the effects of opioids on the upper airway and hypoglossal motor activity and the association of opioid use and obstructive sleep apnea.

CITATION

Freire C, Sennes LU, Polotsky VY. Opioids and obstructive sleep apnea. J Clin Sleep Med. 2022;18(2):647-652.

Effects of acetazolamide on control of breathing in sleep apnea patients: Mechanistic insights using meta-analyses and physiological model simulations

Obstructive and central sleep apnea affects ~1 billion people globally and may lead to serious cardiovascular and neurocognitive consequences, but treatment options are limited. High loop gain (ventilatory instability) is a major pathophysiological mechanism underlying both types of sleep apnea and can be lowered pharmacologically with acetazolamide, thereby improving sleep apnea severity. However, individual responses vary and are strongly correlated with the loop gain reduction achieved by acetazolamide. To aid with patient selection for long-term trials and clinical care, our goal was to understand better the factors that determine the change in loop gain following acetazolamide in human subjects with sleep apnea. Thus, we (i) performed several meta-analyses to clarify how acetazolamide affects ventilatory control and loop gain (including its primary components controller/plant gain), and based on these results, we (ii) performed physiological model simulations to assess how different baseline conditions affect the change in loop gain. Our results suggest that (i) acetazolamide primarily causes a left shift of the chemosensitivity line thus lowering plant gain without substantially affecting controller gain; and (ii) higher controller gain, higher paCO2 at eupneic ventilation, and lower CO2 production at baseline result in a more pronounced loop gain reduction with acetazolamide. In summary, the combination of mechanistic meta-analyses with model simulations provides a unified framework of acetazolamide's effects on ventilatory control and revealed physiological predictors of response, which are consistent with empirical observations of acetazolamide's effects in different sleep apnea subgroups. Prospective studies are needed to validate these predictors and assess their value for patient selection.

Effects of Hydroxychloroquine on endOthelial function in eLDerly with sleep apnea (HOLD): study protocol for a randomized clinical trial

BACKGROUND

Sleep apnea and coronary artery disease are prevalent and relevant diseases. The mechanism by which sleep apnea leads to coronary artery disease remains unclear. Intermittent hypoxia, caused by sleep apnea, leads to inflammation and consequent endothelial dysfunction. Endothelial dysfunction precedes the development of atherosclerotic disease and the occurrence of cardiovascular events. Agents that potentially act to improve endothelial function can help prevent cardiovascular events. Patients using immunomodulators due to rheumatic diseases have a lower prevalence of cardiovascular diseases. However, the potential cardioprotective effect of these drugs in patients without autoimmune diseases is not clear. Hydroxychloroquine (HCQ) is an immunomodulator used to treat rheumatoid arthritis and systemic lupus erythematosus. In addition to its anti-inflammatory properties, HCQ reduces cholesterol and blood glucose levels and has antithrombotic effects. The drug is inexpensive and widely available. Adverse effects of HCQ are rare and occur more frequently with high doses.

OBJECTIVE

In this randomized clinical trial, the effect of HCQ treatment on endothelial function will be tested in seniors with sleep apnea.

METHODS

We will recruit participants over the age of 65 and with moderate-severe sleep apnea from an ongoing cohort. We chose to use this sample already evaluated for sleep apnea for reasons of convenience, but also because the elderly with sleep apnea are vulnerable to heart disease. Endothelial function will be assessed by examining flow-mediated dilation of the brachial artery, the gold standard method, considered an independent predictor of cardiovascular events in the general population and by peripheral arterial tonometry, the most recent and most easily obtained method. Hydroxychloroquine will be used at a dose of 400 mg/daily for 8 weeks.

DISCUSSION

Our study aims to obtain evidence, albeit preliminary, of the efficacy of hydroxychloroquine in improving endothelial function and reducing cardiovascular risk markers. If the improvement occurs, we plan to design a randomized multicenter clinical trial to confirm the findings.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04161339 . Registered on November 2019.

Effects of Growth Hormone Treatment on Sleep-Related Parameters in Adults With Prader-Willi Syndrome

CONTEXT

Prader-Willi syndrome (PWS) is a rare, genetic, multisymptom, neurodevelopmental disease due to lack of the expression of the paternal genes in the q11 to q13 region of chromosome 15. The main characteristics of PWS are muscular hypotonia, hyperphagia, obesity, behavioral problems, cognitive disabilities, and endocrine deficiencies, including growth hormone (GH) deficiency. Sleep apnea and abnormal sleep patterns are common in PWS. GH treatment might theoretically have a negative impact on respiration.

OBJECTIVE

Here we present the effect of GH treatment on polysomnographic measurements.

METHODS

Thirty-seven adults, 15 men and 22 women, with confirmed PWS were randomly assigned to 1 year of GH treatment (n = 19) or placebo (n = 18) followed by 2 years of GH treatment to all. Polysomnographic measurements were performed every 6 months. A mixed-effect regression model was used for comparison over time in the subgroup that received GH for 3 years.

RESULTS

At baseline median age was 29.5 years, body mass index 27.1, insulin-like growth factor 115 µg/L, apnea-hypopnea index (AHI) 1.4 (range, 0.0-13.9), and sleep efficiency (SE) 89.0% (range, 41.0%-99.0%). No differences in sleep or respiratory parameters were seen between GH- and placebo-treated patients. SE continuously improved throughout the study, also after adjustment for BMI, and the length of the longest apnea increased. AHI inconsistently increased within normal range.

CONCLUSION

SE improved during GH treatment and no clinical, significantly negative impact on respiration was seen. The etiology of breathing disorders is multifactorial and awareness of them should always be present in adults with PWS with or without GH treatment.

Pinocembrin ameliorates intermittent hypoxia-induced neuroinflammation through BNIP3-dependent mitophagy in a murine model of sleep apnea

BACKGROUND

Intermittent hypoxia (IH) caused by obstructive sleep apnea (OSA) leads to neuroinflammation. Pinocembrin has been shown to have neuroprotective effects, while the therapeutic functions under IH condition are still unknown.

METHODS

An OSA model was established by CIH exposure inside custom-made chambers. C57BL/6 mice were intraperitoneally injected with pinocembrin (40 mg/kg, i.p.) or vehicle (PBS containing 5% povidone; i.p.), and the changes of behavior on mice were detected by the Morris water maze test. Immunohistochemical staining, western blotting, immunofluorescence assays, and immunoprecipitation were used to investigate the association between NLRP3 inflammasome and BNIP3-dependent mitophagy. The mitochondrial morphology and mitophagosomes were detected under a transmission electron microscope. The detrimental effects of IH were tested by annexin V-FITC/PI staining, Mito SOX Red staining, and JC-1 mitochondrial membrane potential assay.

RESULTS

In this study, our observations in vivo indicated that the administration of pinocembrin can restore spatial learning and memory ability and reduce neuronal apoptosis and hippocampal inflammation. Pinocembrin treatment significantly inhibited the formation of NLRP3 inflammasome and infiltration of microglia and enhanced BNIP3-mediated mitophagy in the hippocampus of IH mice. Additionally, our in vitro results show that pinocembrin protects microglial cells against IH-induced cytotoxicity by activating BNIP3-dependent mitophagy through the JNK-ERK signaling pathway.

CONCLUSIONS

In summary, our findings demonstrated that pinocembrin can act as a potential therapeutic strategy for IH-induced neuroinflammation.

Role of Zinc Supplementation on Ischemia/Reperfusion Injury in Various Organs

Ischemia-reperfusion (I/R) injury is a serious condition which is associated with myocardial infarction, stroke, acute kidney injury, trauma, circulatory arrest, sickle cell disease, and sleep apnea and can lead to high morbidity and mortality. Salts of zinc (Zn) are commonly used by humans and have protective effects against gastric, renal, hepatic, muscle, myocardial, or neuronal ischemic injury. The present review evaluates molecular mechanisms underlying the protective effects of Zn supplement against I/R injury. Data of this review have been collected from the scientific articles published in databases such as Science Direct, Scopus, PubMed, and Scientific Information Database from 1991 to 2019. Zn supplementation increased the decreased parameters including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH), metallothionein (MT), protein sulfhydryl (P-SH), and nuclear factor-erythroid 2-related factor-2 (Nrf2) expression and decreased the increased elements such as endoplasmic reticulum (ER) stress, mitochondrial permeability transition pore (mPTP) opening, malondialdehyde (MDA), serum level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and microRNAs-(122 and 34a), apoptotic factors, and histopathological changes. Zn also increases phosphatidylinositol 3-kinase (PI3K)/Akt and glycogen synthase kinase-3β (GSK-3β) phosphorylation and preserves protein kinase C isoforms. It is suggested that Zn can be administered before elective surgeries for prevention of side effects of I/R injury.

Might chronic opioid use impact sleep-disordered breathing and vice versa?

Orr JE, Wallace MS, Malhotra A. Might chronic opioid use impact sleep-disordered breathing and vice versa? J Clin Sleep Med . 2020;16(6):843–845.

The Effects of Transgender Hormone Therapy on Sleep and Breathing: A Case Series

None

The effect of hormone therapy on sleep-disordered breathing in transgender patients has not been described. We present three cases of patients undergoing gender reassignment and treated with hormone replacement. The first case was a transgender woman (assigned male at birth) with a prolonged history of severe obstructive sleep apnea (OSA) that resolved following initiation of female sex hormones. The second and third cases both address transgender males (assigned female at birth) in whom OSA developed following initiation of male sex hormones (with pretreatment polysomnography documenting absence of OSA). The growing interest in transgender health warrants further evaluation of the effects of related therapies on sleep and sleep-disordered breathing.

The effectiveness of dapagliflozin for sleep-disordered breathing among Japanese patients with obesity and type 2 diabetes mellitus

Weight reduction is important in patients with sleep-disordered breathing (SDB). In Japanese patients, slight weight reduction is effective for improving the severity of SDB. However, the effect of weight reduction after administration of sodium glucose co-transporter 2 (SGLT2) inhibitor for SDB remains unclear. The aim of this study was to evaluate the improvement of SDB from baseline after administration of dapagliflozin (5 mg) once daily for 24 weeks among Japanese patients with obesity and type 2 diabetes mellitus. Thirty Japanese patients with type 2 diabetes mellitus and SDB were enrolled in a 24-week, prospective, open-label, single-arm, multicentre trial. SDB was defined as at least five 3% oxygen desaturation index (ODI) events per hour, and moderate to severe SDB was defined as at least 15 ODI events per hour. The primary endpoint was the change in 3% ODI between before dapagliflozin administration and at 24 weeks. The prevalence of moderate to severe SDB was 20% in the present study. After administration of dapagliflozin, fasting glucose, HbA1c, aspartate aminotransferase, total cholesterol, low-density lipoprotein cholesterol, and estimated globular filtration rate decreased significantly. The improvement of 3% ODI was observed in patients with moderate to severe SDB but not mild SDB (from 25.0 ± 3.8 at baseline to 18.5 ± 6.1 at 24 weeks, p = 0.017). In conclusion, dapagliflozin might improve moderate to severe SDB but not mild SDB in Japanese patients with obesity and type 2 diabetes mellitus.

Impact of Opioid Therapy on Sleep and Respiratory Patterns in Adults With Advanced Cancer Receiving Palliative Care

CONTEXT

In advanced cancer, abnormal sleep patterns may contribute to poor quality of life, but the impact of opioid-related sleep disorders has not been explored in detail in these patients.

OBJECTIVE

To document sleep and respiratory patterns in patients with cancer, receiving a range of opioids, determine factors that contribute to severity of central or obstructive apnea, and to what extent these contribute to sleep disturbance.

METHODS

Adults with advanced cancer admitted to a palliative care service underwent a sleep analysis by an unattended polysomnography. Total sleep time, apnea hypopnea index, central apnea index, obstructive apnea hypopnea index, arousal index, and oxygen desaturation were measured. Baseline assessment included body habitus, Mallampati score, comorbidity indices, concomitant medications, and the Berlin questionnaire. Epworth Sleepiness Scale, Stanford Sleepiness Scale, and Wu cancer fatigue scales were documented.

RESULTS

Twenty-eight patients were studied, including 25 receiving opioids. In the latter group, the apnea hypopnea index was mildly abnormal in six patients and severely abnormal in 10 patients. Central apnea index and obstructive apnea hypopnea index were abnormal in nine and 17 patients, respectively. There was no significant correlation between opioid dose and polysomnographic results.

CONCLUSION

In patients with advanced cancer receiving opioid analgesia, there was a high prevalence of respiratory disturbance, both central and obstructive, and deranged sleep patterns. Addressing sleep-disordered breathing in cancer patients has the potential to improve daytime drowsiness and quality of life.

Sex, stress and sleep apnoea: Decreased susceptibility to upper airway muscle dysfunction following intermittent hypoxia in females

Obstructive sleep apnoea syndrome (OSAS) is a devastating respiratory control disorder more common in men than women. The reasons for the sex difference in prevalence are multifactorial, but are partly attributable to protective effects of oestrogen. Indeed, OSAS prevalence increases in post-menopausal women. OSAS is characterized by repeated occlusions of the pharyngeal airway during sleep. Dysfunction of the upper airway muscles controlling airway calibre and collapsibility is implicated in the pathophysiology of OSAS, and sex differences in the neuro-mechanical control of upper airway patency are described. It is widely recognized that chronic intermittent hypoxia (CIH), a cardinal feature of OSAS due to recurrent apnoea, drives many of the morbid consequences characteristic of the disorder. In rodents, exposure to CIH-related redox stress causes upper airway muscle weakness and fatigue, associated with mitochondrial dysfunction. Of interest, in adults, there is female resilience to CIH-induced muscle dysfunction. Conversely, exposure to CIH in early life, results in upper airway muscle weakness equivalent between the two sexes at 3 and 6 weeks of age. Ovariectomy exacerbates the deleterious effects of exposure to CIH in adult female upper airway muscle, an effect partially restored by oestrogen replacement therapy. Intriguingly, female advantage intrinsic to upper airway muscle exists with evidence of substantially greater loss of performance in male muscle during acute exposure to severe hypoxic stress. Sex differences in upper airway muscle physiology may have relevance to human OSAS. The oestrogen-oestrogen receptor α axis represents a potential therapeutic target in OSAS, particularly in post-menopausal women.

The effect of acetazolamide on sleep apnea at high altitude: a systematic review and meta-analysis

Background:

Acetazolamide has been investigated for treating sleep apnea in newcomers ascending to high altitude. This study aimed to assess the effect of acetazolamide on sleep apnea at high altitude, determine the optimal therapeutic dose, and compare its effectiveness in healthy trekkers and obstructive sleep apnea (OSA) patients.

Methods:

PubMed, Embase, Scopus, Cochrane Library, and Airiti Library databases were searched up to July 2015 for randomized controlled trials (RCTs) performed above 2500 m in lowlanders and that used acetazolamide as intervention in sleep studies. Studies including participants with medical conditions other than OSA were excluded.

Results:

Eight studies of 190 adults were included. In healthy participants, the pooled mean effect sizes of acetazolamide on Apnea–Hypopnea Index (AHI), percentage of periodic breathing time, and nocturnal oxygenation were 34.66 [95% confidence interval (CI) 25.01–44.30] with low heterogeneity (p = 0.7, I² = 0%), 38.56% (95% CI 18.92–58.19%) with low heterogeneity (p = 0.24, I² = 28%), and 4.75% (95% CI 1.35–8.15%) with high heterogeneity (p < 0.01, I² = 87%), respectively. In OSA patients, the pooled mean effect sizes of acetazolamide on AHI and nocturnal oxygenation were 13.18 (95% CI 9.25–17.1) with low heterogeneity (p = 0.33, I² = 0%) and 1.85% (95% CI 1.08–2.62%) with low heterogeneity (P = 0.56, I² = 0%).

Conclusions:

Acetazolamide improves sleep apnea at high altitude by decreasing AHI and percentage of periodic breathing time and increasing nocturnal oxygenation. Acetazolamide is more beneficial in healthy participants than in OSA patients, and a 250 mg daily dose may be as effective as higher daily doses for healthy trekkers.

[LIRAGUTIDE AT A DOSE OF 3.0 MG (SAXENDA): NEW INDICATION FOR THE TREATMENT OF OBESITY]

Liraglutide is an analogue of Glucagon-Like Peptide-1 (GLP-1) already indicated under the trade name of Victoza for the treatment of type 2 diabetes, at usual doses of 1.2 or 1.8 mg as once daily subcutaneous injection. It is henceforth indicated at a dose of 3.0 mg, also as once daily subcutaneous injection, for the treatment of obesity or overweight with comorbidities under the trade name of Saxenda, in combination with diet and exercise. Besides a specific action on the endocrine pancreas, mainly responsible for the antihyperglycaemic effect, liraglutide helps controlling appetite at the hypothamalic level. A specific programme of controlled trials (especially SCALE studies) demonstrated both efficacy and safety of the 3.0 mg dose of liraglutide in obese or overweight patients with various comorbidities.

Cardiovascular Disease and Sleep-Disordered Breathing in Acromegaly

Treatment goals in acromegaly include symptom relief, tumour control and reversal of the excess morbidity and mortality associated with the disorder. Cardiovascular complications include concentric biventricular hypertrophy and cardiomyopathy, hypertension, valvular heart disease and arrhythmias, while metabolic disturbance (insulin resistance/diabetes mellitus, dyslipidaemia) further increases the risk of cardiovascular and cerebrovascular events. Sleep-disordered breathing (in the form of sleep apnoea) is also common in patients with acromegaly and may exacerbate cardiovascular dysfunction, in addition to contributing to impaired quality of life. Accordingly, and in keeping with evidence that cardiorespiratory complications in acromegaly are not automatically reversed/ameliorated simply through the attainment of 'safe' growth hormone and insulin-like growth factor 1 levels, recent guidelines have emphasised the need not only to achieve stringent biochemical control, but also to identify and independently treat these comorbidities. It is important, therefore, that patients with acromegaly are systematically screened at diagnosis, and periodically thereafter, for the common cardiovascular and respiratory manifestations and that biochemical targets do not become the only treatment goal.

Pharmacotherapeutic failure in a large cohort of patients with insomnia presenting to a sleep medicine center and laboratory: subjective pretest predictions and objective diagnoses

OBJECTIVE

To measure the frequency of pharmacotherapeutic failure and its association with the diagnosis of sleep-disordered breathing among patients with chronic insomnia disorder.

PATIENTS AND METHODS

In a retrospective review of medical records from January 1, 2005, through December 31, 2012, we identified an inclusive, consecutive series of 1210 patients with insomnia disorder, 899 (74.3%) of whom used sleep aids either occasionally (168 [18.7%]) or regularly (731 [81.3%]). Patients presented to a community-based sleep medicine center in Albuquerque, New Mexico, with typical referral patterns: 743 (61.4%) were referred by primary care physicians, 211 (17.4%) by specialists, 117 (9.7%) by mental health professionals, and 139 (11.5%) by self-referral. Pharmacotherapeutic failure was assessed from subjective insomnia reports and a validated insomnia severity scale. Polysomnography with pressure transducer (an advanced respiratory technology not previously used in a large cohort of patients with insomnia) measured sleep-disordered breathing. Objective data yielded accuracy rates for 3 pretest screening tools used to measure risk for sleep-disordered breathing.

RESULTS

Of the total sample of 1210 patients, all 899 (74.3%) who were taking over-the-counter or prescription sleep aids had pharmacotherapeutic failure. The 710 patients taking prescription drugs (79.0%) reported the most severe insomnia, the fewest sleep-associated breathing symptoms, and the most medical and psychiatric comorbidity. Of the 942 patients objectively tested (77.9%), 860 (91.3%) met standard criteria, on average, for a moderate to severe sleep-associated breathing disorder, yet pretest screening sensitivity for sleep-disordered breathing varied widely from 63.7% to 100%. Positive predictive values were high (about 90%) for all screens, but a tool commonly used in primary care misclassified 301 patients (32.0% false-negative results).

CONCLUSION

Pharmacotherapeutic failure and sleep-disordered breathing were extremely common among treatment-seeking patients with chronic insomnia disorder. Screening techniques designed from the field of sleep medicine predicted high rates for sleep-disordered breathing, whereas a survey common to primary care yielded many false-negative results. Although the relationship between insomnia and sleep-disordered breathing remains undefined, this research raises salient clinical questions about the management of insomnia in primary care before sleep center encounters.

Severe obstructive sleep apnoea syndrome and erectile dysfunction: a prospective randomised study to compare sildenafil vs. nasal continuous positive airway pressure

BACKGROUND

A high incidence of erectile dysfunction (ED) among patients with obstructive sleep apnoea syndrome (OSAS) has been reported, with a strong correlation between obstructive sleep apnoea, ED, and quality of life (QOL), and it has been estimated that 10-60% of patients with OSAS suffer from ED. In this prospective randomised controlled trial, we investigated 82 men with ED consecutively who were referred to the outpatient clinic for sleep disorders and had severe OSAS (AHI> 30 events/h) without any other comorbidities as a possible cause of ED. The aim of this study was to evaluate and compare the efficacy of sildenafil vs. continuous positive airway pressure (CPAP) in men with ED and severe OSAS.

METHODS

Eighty-two patients were randomised to two main treatment groups: group 1 patients (n = 41) were treated with 100-mg sildenafil 1 h before sexual intercourse without CPAP, and group 2 patients (n = 41 men) were treated with only nasal CPAP during night time sleep. Both groups were evaluated with the same questionnaires (International Index of Erectile Function-EF domain; Sex Encounter Profile; Erectile Dysfunction Inventory Treatment Satisfaction) 12 weeks after treatment.

RESULTS

In patients receiving sildenafil treatment, 58.2% of those who attempted sexual intercourses were successful compared to 30.4% in the CPAP group. The mean number of successful attempts per week was significantly higher in the sildenafil group compared with the CPAP group (2.9 vs. 1.7, respectively; p < 0.0001). The mean IIEF-EF domain scores were significantly higher in the sildenafil group compared with the CPAP group (p < 0.0001). The overall satisfaction rate was 68% with sildenafil treatment and 29% with CPAP treatment.

CONCLUSIONS

This study confirms that severe OSAS is strongly associated with erectile dysfunction. CPAP and sildenafil (100 mg) are safe and effective therapies for OSAS-related ED patients. In the present study sildenafil was more effective than CPAP in treating ED associated with OSAS, as indicated by a significantly higher rate of successful attempts at intercourse and higher IIEF-EF domain scores. Our study, to date, is the only that has investigated sildenafil in patients with severe OSAS.

[Observation the clinical curative effect of children's laryngopharyngeal reflux and sleep apnea hypopnea syndrome]

OBJECTIVE

To observe the clinical curative effect of anti-reflux treatment for obstructive sleep apnea hypopnea syndrome (OSAHS) in children.

METHODS

Twenty children with sleep-disordered breathing were included in this study. There were 15 males and 5 females, aged 3-9 years old, median 6 years old. The electronic laryngoscope, polysomnography (PSG) monitoring, Reflux symptom index (RSI) questionnaire and Reflux finding score (RFS) were used to establish the initial diagnosis of OSAHS with LPRD, preclude adenoid hypertrophy and tonsil hypertrophy and nasal disorders. Oral Domperidone and Omeprazole were given for treatment. For children under 3-year-old, the dosage of Domperidone was 0.6 ml.kg⁻¹.day⁻¹.For children over 3-year-old, Domperidone combined with Omeprazole were given with the dosage of 0.3 mg.kg⁻¹.day⁻¹.

RESULTS

After 4 weeks of treatment, 19 patients symptoms of OSAHS include disturbed sleep, dyspnoea and apneic attack improved. After 8 weeks of treatment, 20 cases with OSAHS symptoms improved than before treatment. Under the electronic laryngoscope, the decrease in pharyngeal lymphoid follicles, the epiglottis, aryepiglottic fold and scoop intergenic region erythema shallow, edema lessened. After treatment of 4 weeks and 8 weeks, there was statistically significant (P < 0.05). Before and after treatment, the difference of RFS was statistically significant (P < 0.05); PSG monitoring proved significant effect in 3 cases (15.0%), effective in 11 cases (55.0%) and 6 cases were ineffective (30.0%). Twenty patients with obstructive apnea index change was not obvious (P > 0.05), apnea hypopnea index and lowest artery oxygen saturation better, differences were statistically significant (Z of 2.819 and 2.733 respectively, P < 0.05).

CONCLUSION

The treatment of LPRD can improve the symptoms of OSAHS, these two diseases may coexist in mutual relations.

Past and present in drug treatment of sleep disorders

Sleep disorders are frequent and disturbing, mostly chronic conditions. Despite the fact practice of sleep medicine is a young field. Sleep disorders were reduced to insomnia and even insomnia was not well studied until 1960ies. This article maps amazing development of sleep disorders treatment from the beginning till current date. The text covers both scientific and clinical perspectives on most frequent sleep related disorders including insomnias, hypersomnias, parasomnias, sleep related movement and breathing disorders, restless legs syndrome and circadian rhythm sleep disorders.

Prader-Willi syndrome and sleep-disordered breathing

Prader-Willi Syndrome is a complex neurogenetic disorder characterized by appetite dysregulation, obesity with decreased muscle mass and increased fat mass, behavioral problems, various endocrinopathies, and sleep and respiratory abnormalities. Respiratory issues include both central and obstructive sleep apnea, excessive daytime sleepiness, narcolepsy, and impaired ventilatory control. There is some controversy as to whether growth hormone treatment, which is the standard of care for patients with Prader-Willi Syndrome, exacerbates or ameliorates the sleep-disordered breathing issues associated with this syndrome. The natural history of sleep and breathing issues and the issues surrounding growth hormone treatment on sleep-disordered breathing are discussed.

The impact of sleep apnea treatment on carbohydrate metabolism in patients with acromegaly

Sleep Apnea is highly prevalent and may contribute to insulin resistance in patients with acromegaly. The primary aim of this study was to assess the impact of sleep apnea treatment with a continuous positive air pressure (CPAP) device on insulin resistance evaluated by hyperinsulinemic euglycemic clamp (HEC). A prospective, randomized, open label, placebo-controlled, crossover study was performed at a tertiary outpatient pituitary center. Twelve acromegalic subjects on somatostatin analogs (SA) with a recent diagnosis of moderate to severe sleep apnea were randomized to CPAP therapy or to nasal dilator adhesive (NDA) with placebo effect for 3 months and then crossed over for another 3 months period without washout. Assessment of HEC, mathematical insulin resistance indexes (HOMA, HOMA2 and QUICKI), GH, IGF-1, HbA1c and free fat acids were performed. A significant reduction on insulin resistance was demonstrated by HEC at the end of the study in patients on CPAP (HEC, pre- and post-CPAP: 4.27 vs. 6.10 mg/Kg/min, P = 0.032). This reduction was not observed in NDA group (HEC, pre- and post-adhesive: 5.53 vs. 5.19 mg/Kg/min, P = 0.455). There was no significant difference on HbA1c or on peripheral insulin resistance indexes in both treatments. CPAP promoted a significant increase on peripheral insulin sensitivity in acromegalic patients with moderate to severe sleep apnea on SA use. Our results support the concept that sleep apnea plays an important role on glucose metabolism. Insulin resistance indexes were unable to detect this finding.

A comprehensive study of clinical, biochemical, radiological, vascular, cardiac, and sleep parameters in an unselected cohort of patients with acromegaly undergoing presurgical somatostatin receptor ligand therapy

CONTEXT

Attainment of safe GH and IGF-1 levels is a central goal of acromegaly management.

OBJECTIVE

The aim of this study was to determine the extent to which reductions in GH and IGF-1 concentrations correlate with amelioration of radiological, metabolic, vascular, cardiac, and respiratory sequelae in a single unselected patient cohort.

STUDY DESIGN

This was a prospective, within-subject comparison in 30 patients with newly diagnosed acromegaly (15 women and 15 men: mean age, 54.3 years; range, 23-78 years) before and after 24 weeks of lanreotide Autogel (ATG) therapy.

RESULTS

Reductions in GH and IGF-1 concentrations and tumor volume were observed in all but 2 patients (median changes [Δ]: GH, -6.88 μg/L [interquartile range -16.78 to -3.32, P = .000001]; IGF-1, -1.95 × upper limit of normal [-3.06 to -1.12, P = .000002]; and pituitary tumor volume, -256 mm(3) [-558 to -72.5, P = .0002]). However, apnea/hypopnea index scores showed highly variable responses (P = .11), which were independent of ΔGH or ΔIGF-1, but moderately correlated with Δweight (R(2) = 0.42, P = .0001). Although systolic (P = .33) and diastolic (P = .76) blood pressure were unchanged, improvements in arterial stiffness (aortic pulse wave velocity, -0.4 m/s [-1.2 to +0.2, P = .046]) and endothelial function (flow mediated dilatation, +1.73% [-0.32 to +6.19, P = .0013]) were observed. Left ventricular mass index regressed in men (-11.8 g/cm(2) [-26.6 to -1.75], P = .019) but not in women (P = .98). Vascular and cardiac changes were independent of ΔGH or ΔIGF-1 and also showed considerable interindividual variation. Metabolic parameters were largely unchanged.

CONCLUSIONS

Presurgical ATG therapy lowers GH and IGF-1 concentrations, induces tumor shrinkage, and ameliorates/reverses cardiac, vascular, and sleep complications in many patients with acromegaly. However, responses vary considerably between individuals, and attainment of biochemical control cannot be assumed to equate to universal complication control.

Armodafinil for sarcoidosis-associated fatigue: a double-blind, placebo-controlled, crossover trial

CONTEXT

Fatigue has been identified in more than one-half of patients with sarcoidosis. Although fatigue is not synonymous with impaired quality of life, most studies of sarcoidosis identify fatigue as a major cause of impaired quality of life.

OBJECTIVES

To test the hypothesis that stimulants may have a role in the treatment of fatigued sarcoidosis patients, even without objective evidence of daytime sleepiness.

METHODS

This was a double-blind, placebo-controlled, crossover study of sarcoidosis patients followed up in one sarcoidosis clinic Sarcoidosis patients with fatigue received either armodafinil or placebo with eight weeks of therapy for each arm and a two week washout period before crossover to the other treatment. Initial armodafinil dose was 150mg and increased to 250mg after four weeks. Patients underwent polysomnography and multiple sleep latency testing (MSLT) the following day. Patients with an apnea/hypopnea index <6/hour received either armodafinil or placebo. Polysomnography with MSLT was repeated after each treatment arm.

RESULTS

Fifteen patients received the study drug. Fatigue was assessed using the Fatigue Assessment Scale (the lower the score, the less the fatigue) and the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) (the higher the score, the less the fatigue). After eight weeks of therapy, there was a significant improvement in the Fatigue Assessment Scale during armodafinil treatment (median -4.5, range -20, 5) compared with placebo treatment (median 3.5, range -9, 14, P<0.05) and for the FACIT-F (armodafinil: median 9, range -12, 26 vs. placebo: median -5, range -17, 11, P<0.005). This improvement in fatigue was seen for both those with and without shortened sleep onset latency time during the MSLT.

CONCLUSION

Armodafinil treatment led to a significant reduction in fatigue in sarcoidosis patients. This effect was seen even in patients who did not have excessive daytime somnolence.

Use of ramelteon for the treatment of secondary REM sleep behavior disorder

We used ramelteon to treat two patients with secondary REM sleep behavior disorder (RBD) complications along with neurodegenerative diseases including multiple system atrophy and Parkinson's disease. These two patients not only improved in terms of their clinical RBD symptoms but also exhibited a decrease in the proportion of REM sleep without atonia (from 8.5% to 3.5% and from 10.9% to 3.9% in the two patients). Although clonazepam is the standard first-line therapy for the treatment of RBD, ramelteon might be an effective treatment alternative in patients with RBD who cannot take clonazepam due to either ineffectiveness or adverse effects.

Genetic basis of apnoea of prematurity and caffeine treatment response: role of adenosine receptor polymorphisms: genetic basis of apnoea of prematurity

AIM

Caffeine treatment reduces the frequency of apnoea of prematurity (AOP) and eliminates the need for mechanical ventilation by acting as a nonspecific inhibitor of adenosine A1 and adenosine 2A receptors. Patients with AOP have demonstrated variant responses to caffeine therapy. We proposed to investigate the role of A1 and 2A polymorphisms in the development of AOP and individual differences in caffeine response. Secondly, we aimed to determine whether these polymorphisms have any effect on bronchopulmonary dysplasia (BPD) development.

METHODS

Cord blood samples were collected from infants born with gestational ages between 24 and 34 weeks. Two groups were defined: patients without apnoea (n = 60) and patients with apnoea (n = 55). Patients with apnoea were divided into two subgroups: a caffeine-responsive group (n = 30) and an unresponsive group (n = 25). Six single-nucleotide polymorphisms were chosen for genotyping.

RESULTS

Patients with apnoea over 28 weeks of gestational age who responded to the caffeine treatment were found to carry the rs16851030 C/C genotype rather than the C/T or T/T genotype. Logistic regression analysis showed a significant correlation between rs35320474-C/T and T/T genotypes and apnoea and BPD development.

CONCLUSION

Our results indicate a role for adenosine receptor gene polymorphisms in susceptibility to AOP and BPD and in interindividual variability to caffeine response.

Melatonin - a somniferous option which does not aggravate sleep-disordered breathing in cardiac risk patients: a Holter ECG based study

BACKGROUND AND AIM

We hypothesised that melatonin may represent a safe somniferous drug for cardiac patients, and assessed the effects of administering 5 mg of melatonin daily before bedtime for 30 days in patients with coronary artery disease (CAD) regarding changes in the nocturnal breathing pattern.

METHODS

Sixty patients with CAD (aged 48-80 years) were randomised to melatonin/placebo treatment in a 2:1 ratio. A Holter ECG-based method (Lifescreen Apnea software) which has been validated as a screening tool for sleep-disordered breathing was used to estimate the apnoea/hypopnoea index (AHI). A 24-h Holter ECG was used to detect nocturnal breathing abnormalities at the beginning and at the end of the observation. The values of estimated AHI (eAHI) ≤ 15 were classified as optimal (Opt) and those 〉 15 - as pathological (Pat). A change of the breathing pattern was classified on the basis of the transition between the initial and final eAHI status (Opt→Opt; Opt→Pat; Pat→Pat, Pat→Opt). The mean initial and final value of eAHI and the percent of Opt and Pat values of eAHI in the initial and final assessment were compared between the melatonin and the placebo groups.

RESULTS

The breathing pattern was not affected by melatonin - the mean initial value of the eAHI in the melatonin group was 18.2 ± 9.4, and in the placebo group 19.6 ± 12.3 (p = 0.64), whereas at the end of the observation in the melatonin group it increased by 1.2 ± 11.3, and in the placebo group - by 1.0 ± 9.0 (p = 0.44).

CONCLUSIONS

Hypnagogic treatment with melatonin did not worsen the eAHI in patients with CAD.

Effects of 5-hydroxytryptamine and 5-hydroxytryptamine 2A/2C agonist on the genioglossus activity and sleep apnea in rats

BACKGROUND

5-Hydroxytryptamine (5-HT) is a common neurotransmitter in the brain which plays an important role in the pathogenesis of sleep apnea. Dysfunction of 5-HT and 5-HT(2) receptors may lead to the collapse of the upper airway and the instability of respiratory control, which in turn produce apnea. Genioglossus (GG) is one of the most important oropharyngeal muscles maintaining the upper airway open. The present study aimed to investigate the effects of 5-HT and 5-HT(2) receptor on GG activity and the sleep apnea in Sprague-Dawley (SD) rats.

METHODS

Microinjection probes were placed within the fourth ventricle of sixteen SD rats. After recovery for a week, the electromyogram (EMG) of GG was recorded in the anesthetized and vagotomized rats. The changes of GG activity before and after the microinjection of 5-HT or 5-HT(2A/2C) agonist -2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI) were observed. Probes were also laid in another eight SD rats. Electroencephalogram (EEG), EMG of neck muscle and respiration were recorded at the same time a week later. The effects of DOI on the occurrence of sleep apnea were explored.

RESULTS

Both 5-HT and DOI significantly enhanced the activity of GG just 3 minutes after the completion of injection. The effect of 5-HT disappeared quickly and the effect of DOI lasted for more than 27 minutes. DOI also significantly decreased the post-sigh apnea index in non-rapid-eye-movement (NREM) and rapid-eye-movement (REM) sleep and decreased the spontaneous apnea index only in NREM sleep (P < 0.05, respectively).

CONCLUSION

5-HT and 5-HT(2A/2C) system correlated closely with the pathogenesis of the sleep apnea syndrome and 5-HT receptors may become the target of the drug treatment.

Comparison of the effects of nebivolol and valsartan on BP reduction and sleep apnoea activity in patients with essential hypertension and OSA

OBJECTIVES

To investigate the effect of nebivolol, a third generation beta-blocker, on blood pressure (BP) reduction and polysomnographic parameters in hypertensive patients with mild-to-moderate obstructive sleep apnoea (OSA).

METHODS

In this double-blind, parallel group study, patients were randomized to nebivolol 5 mg or valsartan 80 mg once daily following a 14-day, placebo run-in period during which any antihypertensive medication were discontinued. BP and heart rate measurements and overnight polysomnography were performed at baseline and after 6 weeks of treatment. Safety and tolerability were assessed.

RESULTS

Thirty-one patients were randomized to nebivolol (n = 16) or valsartan (n = 15). After six weeks both systolic and diastolic BP were effectively reduced by both treatments. Reductions in BP were not statistically significant different between agents, but mean heart rate was significantly decreased with nebivolol (compared with valsartan (p < 0.001). There was no statistically significant difference between both treatments for the change from baseline to treatment end for mean (+/-SD) Apnoea Hypopnoea Index (AHI) (nebivolol: 23.0 +/- 9.2 to 27.9 +/- 21.2 events/h; valsartan: 23.8 +/- 6.6 to 22.5 +/- 18.0 events/h; p = 0.48) or for any other sleep-related parameters. Both agents were well tolerated.

CONCLUSION

Nebivolol has a significant BP reduction effect in patients with OSA that is similar to valsartan and reduces heart rate to a greater extent which may prove beneficial in selected patients.

[Effects of 5-HT2 agonist/antagonist on sleep apnea in Sprague-Dawley rats]

OBJECTIVE

To evaluate the effects of 5-HT2 agonist/antagonist Ketanserin on sleep apnea in Sprague-Dawley (SD) rats.

METHODS

Twenty adult male SD rats were operated for implantation of EEG and EMG electrodes and a microinjection probe was placed within the fourth ventricle. After recovery for a week, rats were monitored for sleep and respiration in three continuous days. There is no intervention on the first day. Before monitoring, 40 microl ACSF were microinjected into the IV ventricle of the rats on the second day. On the third day before monitoring, 40 microl DOI were microinjected into the IV ventricle of ten rats and 40 microl Ketanserin into another ten ones.

RESULTS

Compared with blank control and microinjection of ACSF, DOI significantly reduced the total apnea index (AI) from 18.3 (11.1, 20.3) times/h and 15.2 (11.4, 18.0) times/h to 10.8 (3.1, 14.1) times/h (P=0.005 and 0.005, respectively). Post sign apnea index (PSAI) during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep as well as spontaneous apnea index (SPAI) during NREM sleep were all significantly decreased; (P<0.05, respectively); while it had no effect on SPAI during REM sleep (P>0.05). Neither sleep efficiency (the percent of total sleep time in total monitoring time) nor the time ratio of NREM sleep and REM sleep was significantly changed. In contrast to blank control and microinjection of ACSF, Ketanserin significantly reduced the total apnea index (AI) from 19.2 (13.7, 20.9) times/h and 19.0 (12.9, 21.6) times/h to 13.1 (9.5, 14.9) times/h (P=0.005 and 0.005, respectively). PSAI during NREM and REM sleep were significantly decreased (P<0.05, respectively). SPAI during NREM and REM sleep were changed without statistically significant (P>0.05, respectively). It also had no effects on sleep efficiency and the time ratio of NREM sleep and REM sleep.

CONCLUSION

Both 5-HT2 agonist and antagonist decreased the sleep apnea index and had no effects on sleep structure. It shows that the role of 5-HT2 receptor in the respiratory regulation during sleep is complex. The mechanisms involved remain to be studied in future.

Proof of concept study: does fenofibrate have a role in sleep apnoea syndrome?

OBJECTIVE

To investigate the effect of fenofibrate on sleep apnoea indices.

METHODS

Proof-of-concept study comprising a placebo run-in period (1 week, 5 weeks if fibrate washout was required) and a 4-week randomized, double-blind treatment period. Thirty-four subjects (mean age 55 years, body mass index 34 kg/m 2 , fasting triglycerides 3.5 mmol/L) with diagnosed sleep apnoea syndrome not treated with continuous positive airways pressure were enrolled and randomized to once daily treatment with fenofibrate (145 mg NanoCrystal(R) tablet) or placebo. Overnight polysomnography, computerized attention/vigilance tests and blood sampling for measurement of lipids, insulin, fasting plasma glucose and fibrinogen were performed at the end of each study period.

CLINICAL TRIAL REGISTRATION

NCT00816829.

MAIN OUTCOME MEASURES

As this was an exploratory study, a range of sleep variables were evaluated. The apnoea/hypopnoea index (AHI) and percentage of time spent with arterial oxygen saturation (SpO(2)) <90% were relevant as they have been evaluated in other clinical trials. Other variables included total apnoeas, hypopnoeas and oxygen desaturations, and non-cortical micro-awakenings related to respiratory events per hour.

RESULTS

Fenofibrate treatment significantly reduced the percentage of time with SpO(2) <90% (from 9.0% to 3.5% vs. 10.0% to 11.5% with placebo, p = 0.007), although there was no significant change in the AHI (reduction vs. control 14% (95%CI -47 to 40%, p = 0.533). Treatment reduced obstructive apnoeas (by 44%, from 18.5 at baseline to 15.0 at end of treatment vs. 29.0 to 30.5 on placebo, p = 0.048), and non-cortical micro-awakenings per hour (from 23.5 to 18.0 vs. 24.0 to 25.0 with placebo, p = 0.004). Other sleep variables were not significantly influenced by fenofibrate.

KEY LIMITATIONS

Exploratory study in patients with mild to moderate sleep apnoea, limited treatment duration; concomitant hypnotic treatment (35%); lack of correction for multiplicity of testing.

CONCLUSIONS

The consistent direction of change in sleep indices in this proof-of-concept study may support further investigation of fenofibrate in moderate to severe sleep apnoea syndrome.

Melatonin and sleep-related problems in children with intractable epilepsy

Children with epilepsy have high rates of sleep problems. Melatonin has been advocated in treatment of sleep disorders, and its beneficial effect has been confirmed in insomnia. The aim of this study was to assess melatonin levels in children with intractable epilepsy and its relation to pattern of sleep and characteristics of seizure disorder, as well as the effect of melatonin therapy on those parameters. The study was conducted on 23 children with intractable epilepsy and 14 children with controlled seizures. Patients were evaluated by psychometric sleep assessment and assay of diurnal and nocturnal melatonin levels. Children with intractable epilepsy received oral melatonin before bedtime. They were reassessed after 3 months. Children with intractable epilepsy had higher scores for each category of sleep walking, forcible teeth grinding, and sleep apnea. At the end of therapeutic trial, patients with intractable epilepsy exhibited significant improvement in bedtime resistance, sleep duration, sleep latency, frequent nocturnal arousals, sleep walking, excessive daytime sleepiness, nocturnal enuresis, forcible teeth grinding, sleep apnea, and Epworth sleepiness scores. There was also significant reduction in seizure severity. Thus, use of melatonin in patients with intractable seizures was associated with improvement of both many sleep-related phenomena and the severity of seizures.

[Dopaminergic stimulation in the non-motor symptoms of Parkinson's disease]

INTRODUCTION AND DEVELOPMENT

The non-motor symptoms of Parkinson's disease have a great impact in terms of quality of life. They are frequently underdiagnosed and clinical experience suggests that not only is dopamine therapy ineffective but that in many cases it is also responsible for the appearance of some of these symptoms. Different studies have drawn attention to the involvement of the dopaminergic pathways in the pathogenesis of some non-motor symptoms. It has been observed that they can undergo fluctuations in relation to dopaminergic stimulation, generally in wearing off states, while displaying a significant correlation with motor fluctuations and a clinical response with continuous dopaminergic therapy.

CONCLUSIONS

Although recent reviews offer insufficient evidence for treatment of non-motor symptoms with dopaminergic therapy, involvement of the dopaminergic pathways in the aetiopathogenesis of some of these disorders and the clinical observation that such symptoms undergo fluctuations in relation to pulsatile dopaminergic stimulation may lead us to reconsider the possible role of dopaminergic therapy in the treatment of these symptoms.

Influence of disease control with pegvisomant on sleep apnoea and tongue volume in patients with active acromegaly

OBJECTIVES

Sleep apnoea has been consistently reported to occur in acromegaly. In uncontrolled patients, the severity of sleep apnoea influences physical activity in the daytime. We investigated the influence of disease activity on tongue volume and sleep apnoea treated with the GH receptor antagonist pegvisomant in poorly controlled patients with acromegaly under octreotide.

DESIGN AND METHODS

A total of 12 patients with active acromegaly (six females; six males; mean age 57+/-15 years; body mass index 29.4+/-4.2 kg/m(2); mean+/-S.D.) were treated with pegvisomant (13.5+/-5.0 mg/die) for 6 months. Tongue volume was examined by magnetic resonance imaging, and sleep apnoea was characterized by polysomnography before and after 6 months of treatment with pegvisomant. The mandibular length was determined by lateral X-ray films.

RESULTS

IGF1 levels decreased after 6 months in all patients (407+/-114 to 199+/-23 microg/l; P=0.0001). The tongue volume decreased (105+/-33 to 83+/-33 ml; P=0.007) as well as the apnoea-hypnoea index (23+/-22 to 18+/-18/h; P=0.0066). The mandibular length correlated with the initial tongue volume (r(2)=0.6072, P=0.0028).

CONCLUSION

In conclusion, successful treatment with pegvisomant can decrease tongue volume, which has benefits for coexisting sleep disordered breathing.

Central cholinergic regulation of respiration: nicotinic receptors

Nicotinic acetylcholine receptors (nAChRs) are expressed in brainstem and spinal cord regions involved in the control of breathing. These receptors mediate central cholinergic regulation of respiration and effects of the exogenous ligand nicotine on respiratory pattern. Activation of alpha4* nAChRs in the preBötzinger Complex (preBötC), an essential site for normal respiratory rhythm generation in mammals, modulates excitatory glutamatergic neurotransmission and depolarizes preBötC inspiratory neurons, leading to increases in respiratory frequency. nAChRs are also present in motor nuclei innervating respiratory muscles. Activation of post- and/or extra-synaptic alpha4* nAChRs on hypoglossal (XII) motoneurons depolarizes these neurons, potentiating tonic and respiratory-related rhythmic activity. As perinatal nicotine exposure may contribute to the pathogenesis of sudden infant death syndrome (SIDS), we discuss the effects of perinatal nicotine exposure on development of the cholinergic and other neurotransmitter systems involved in control of breathing. Advances in understanding of the mechanisms underlying central cholinergic/nicotinic modulation of respiration provide a pharmacological basis for exploiting nAChRs as therapeutic targets for neurological disorders related to neural control of breathing such as sleep apnea and SIDS.

[Neurobiology of sleep apnea: implication for therapy?]

An accumulating body of evidence from animal investigations supports the potential importance of vagal afferent pathways in the pathogenesis and/or therapy of SRBD. The neurochemistry and neuropharmacology of this pathway offers numerous possible targets for pharmacologic modulation. Defining the ultimate clinical relevance of these pathways in SRBD pathogenesis and treatment can only be accomplished with significant ongoing clinical and basic investigation.

The 5-min pupillary alertness test is sensitive to modafinil: a placebo controlled study in patients with sleep apnea

RATIONALE

The extent of pupillary miosis during 5 min in darkness is a simple, recently introduced alertness test which may become useful in the clinical assessment of normal and pathological sleepiness.

OBJECTIVES

In this study, we further validated this test by testing its sensitivity to the effects of modafinil, a non-stimulant, alertness-promoting drug.

METHODS

Twelve unmedicated patients recently diagnosed with obstructive sleep apnea (OSA) after polysomnography, received placebo or modafinil (200 mg), according to a double-blind, cross-over design. The patients' resting pupil diameter (RPD) was sampled over 5 min in darkness before (10:00 A.M.) and after treatment (2:00 P.M.), and their light reflexes were elicited and recorded in darkness with an infrared video pupillometer.

RESULTS

We found a circadian miosis at 2:00 P.M. in the placebo treatment condition, which was reversed by modafinil. This effect correlated with modafinil-induced increase in subjective alertness, and it was greater in the most severely affected patients in terms of lowest oxygen saturation, independently of body mass index, age, or apneic episodes during sleep. Modafinil reduced the light reflex amplitude, suggesting an increase in the inhibitory input at the pupilloconstrictor Edinger-Westphal nucleus.

CONCLUSIONS

These effects of modafinil are best explained via an activation of the hypoxia-sensitive nucleus locus coeruleus. The 5-min pupillary alertness test has promising predictive validity, and it holds promise as a fast and sensitive method for the objective assessment of excessive daytime sleepiness, monitoring of disease progression, and response to treatment.

Severe sleep-disordered breathing in a patient with Brown–Vialetto–Van Laere syndrome: Polysomnographic findings

Brown-Vialetto-Van Laere (BVVL) syndrome is a rare disorder with clinical features that include progressive bilateral sensorineural deafness and a variety of cranial nerve impairments. Respiratory compromise has been observed in most familial and sporadic cases; however, few studies have been published regarding sleep-disordered breathing in this syndrome. We report the unique case of a 16-year-old girl with the clinical features of BVVL syndrome who presented with bilateral sensorineural hearing loss and then progressively developed paralysis of the 7th and 9th-12th cranial nerves. More importantly, she presented with the unusual feature of severe sleep-disordered breathing. A polysomnographic study showed evidence of dominant central sleep apnea, and the majority of apneic episodes more likely occurred in stage 2 during NREM sleep. The central sleep apnea was associated with rapid respiratory deterioration and death. This report raises the fact that a patient with BVVL syndrome may present with severe sleep-disordered breathing as a life-threatening condition, which emphasizes the need for greater attention to the early detection of potential sleep-disordered breathing in these afflicted with the BVVL syndrome for optimal clinical management.

Hypothalamic-pituitary-adrenal axis activity in obese men with and without sleep apnea: effects of continuous positive airway pressure therapy

CONTEXT

Previous studies on the association between the hypothalamic-pituitary-adrenal axis activity and sleep apnea (SA) and obesity are inconsistent and/or limited.

OBJECTIVE

In this study, we evaluated the activity of the hypothalamic-pituitary-adrenal axis in nonpsychologically distressed obese subjects with and without SA and examined the impact of continuous positive airway pressure (CPAP) in SA patients.

DESIGN AND PARTICIPANTS

In study I, four-night sleep laboratory recordings and serial 24-h plasma measures of cortisol were obtained in 45 obese men with and without apnea and nonobese controls. Sleep apneic patients were reassessed after 3 months of CPAP use. In study II, 38 obese men with and without sleep apnea and nonobese controls were challenged with ovine CRH administration after four nights in the sleep laboratory.

RESULTS

The sleep patterns were similar between obese and nonobese controls. Twenty-four-hour plasma cortisol levels were highest in nonobese controls, intermediate in obese apneic patients, and lowest in obese controls (8.8 +/- 0.4 vs. 8.1 +/- 0.3 vs. 7.5 +/- 0.3 microg/dl, P < 0.05). CPAP tended to reduce cortisol levels in the apneic patients (difference -0.7 +/- .4 microg/dl, P = 0.1). CRH administration resulted in a higher ACTH response in both obese groups, compared with nonobese controls; the three groups were not different in cortisol response.

CONCLUSIONS

Nonpsychologically distressed, normally sleeping, obese men had low cortisol secretion. The cortisol secretion was slightly activated by SA and returned to low by CPAP use. The low cortisol secretion in obesity through its inferred hyposecretion of hypothalamic CRH might predispose the obese to sleep apnea.

Improvement of anemia with erythropoietin and intravenous iron reduces sleep-related breathing disorders and improves daytime sleepiness in anemic patients with congestive heart failure

BACKGROUND

Central sleep apnea (CSA) (with or without Cheyne-Stokes breathing) or obstructive sleep apnea (OSA) are common in congestive heart failure (CHF). Correction of anemia may improve CHF. We hypothesized that correction of anemia might also improve sleep-related breathing disorders (SRBDs) in CHF.

METHODS

Thirty-eight patients with CHF and anemia (hemoglobin level < 12 g/dL) were treated with erythropoietin and intravenous iron to a target hemoglobin level of 13 g/dL. Home sleep recordings were done before and after 3 months of treatment.

RESULTS

Thirty-seven patients had SRBD (Apnea Hypopnea Index [AHI] of > or = 10). Hemoglobin level increased from 10.4 +/- 0.8 to 12.3 +/- 1.2 g/dL (P < .001). Total AHI values decreased from 35.9 +/- 12.2 to 24.9 +/- 12.2 (P < .001). The AHI of CSA, OSA and Cheyne-Stokes breathing decreased from 26.5 +/- 14.6 to 18.6 +/- 7.7, from 9.4 +/- 10.9 to 6.9 +/- 9.8, and from 13.1 +/- 16.4 to 9.0 +/- 12.2, respectively (all P < .05). Sleep minimal oxygen saturation (SaO2) increased from 62% +/- 12% to 71% +/- 11%; Epworth Sleepiness Scale score improved from 9.4 +/- 6.2 to 6.0 +/- 5.0 and New York Heart Association class improved from 2.9 +/- 0.4 to 1.7 +/- 0.7, all P < .001. Hemoglobin level improvement correlated with improvement in OSA+CSA, CSA, minimal SaO2, Epworth Sleepiness Scale score, and New York Heart Association class (all P < .001).

CONCLUSION

Improvement of anemia in CHF is associated with a reduction in SRBD and an improvement in daytime sleepiness.

Sleep apnea is induced by a high-fat diet and reversed and prevented by metformin in non-obese rats

OBJECTIVE

We assessed the relationship between a high-fat (HF) diet and central apnea during rapid eye movement and non-rapid eye movement sleep stages by recording ventilatory parameters in 28 non-obese rats in which insulin resistance had been induced by an HF diet. We also studied whether metformin (an anti-hyperglycemic drug frequently used to treat insulin resistance) could reverse sleep apnea or prevent its occurrence in this experimental paradigm.

RESEARCH METHODS AND PROCEDURES

Rats were fed with a standard diet (10 rats), an HF diet (8 rats), or an HF diet concomitantly with metformin treatment (10 rats). Each animal was instrumented for electroencephalographic and electromyographic recording. After 3 weeks, ventilatory parameters during sleep were recorded with a body plethysmograph. All rats were treated with metformin for 1 week, after which time the ventilatory measurements were measured again.

RESULTS

Our results showed that the three groups of animals did not differ in terms of body growth over the entire experimental period. The HF diet did not modify sleep structure or minute ventilation in the different sleep stages. A great increase (+266 +/- 48%) in central apnea frequency was observed in insulin-resistant rats. This was explained by an increase in both post-sigh (+195 +/- 35%) and spontaneous apnea (+437 +/- 65%) in the different sleep stages. These increases were suppressed by metformin treatment.

DISCUSSION

Insulin resistance induced by the HF diet could be the promoter of sleep apnea in non-obese rats. Metformin is an efficient curative and preventive treatment for sleep apnea, suggesting that insulin resistance modifies the ventilatory drive independently of obesity.

Does beta-blocker treatment influence central sleep apnoea?

Chronic severe heart failure is frequently associated with disturbances in the central control of breathing. During wakefulness, central breathing disorders could be ameliorated with beta-blocker treatment, but nothing is known about the effects of beta-blockers on the control of breathing during sleep. This study intends to determinate the prevalence and severity of nocturnal apnoeas and hypopnoeas in heart failure patients treated with or without metoprolol or carvedilol. Fifty consecutive patients with dilated cardiomyopathy in NYHA class II-IV with a left ventricular ejection fraction (LVEF) of 35% or below were studied with full polysomnography over one night. The mean Apnoea-Hypopnoea Index of beta-blocker free patients was 19.8+/-14.2 versus 7.4+/-8.5 (p<0.05) and 8.7+/-8.1 (p<0.05) in patients treated with metoprolol or carvedilol, respectively. The arousal index, sleep quality, and daytime sleepiness were improved in similar magnitude.

CONCLUSION

Long-term treatment of patients with advanced chronic heart failure with sufficient doses of metoprolol or carvedilol is associated with a lower prevalence and severity of central sleep apnoea (CSA).

Effects of progesterone on sleep: a possible pharmacological treatment for sleep-breathing disorders?

Progesterone is present in a wide spectrum of biological activity within a variety of tissues. This hormone is also known to affect reproduction, sleep quality, respiration, mood, appetite, learning, memory and sexual activity. Progesterone exerts a sleep induction or hypnotic effect and is a potent respiratory stimulant that has been associated to a decrease in the number of central and obstructive sleep apnea episodes in men. The literature also contains a substantial amount of data on the effect of apnea in women with obesity-hypoventilation during menopause. This review attempts to outline the specific role of progesterone in normal sleep and breathing as well as its possible therapeutic effects in the treatment of sleep-disordered breathing.

Sleep-related breathing disorders in prepubertal children with Prader-Willi syndrome and effects of growth hormone treatment

CONTEXT

Recently, several cases of sudden death in GH-treated and non-GH-treated, mainly young Prader-Willi syndrome (PWS), patients were reported. GH treatment in PWS results in a remarkable growth response and an improvement of body composition and muscle strength. Data concerning effects on respiratory parameters, are however, limited.

OBJECTIVE

The objective of the study was to evaluate effects of GH on respiratory parameters in prepubertal PWS children.

DESIGN

Polysomnography was performed before GH in 53 children and repeated after 6 months of GH treatment in 35 of them.

PATIENTS

Fifty-three prepubertal PWS children (30 boys), with median (interquartile range) age of 5.4 (2.1-7.2) yr and body mass index of +1.0 sd score (-0.1-1.7).

INTERVENTION

Intervention included treatment with GH 1 mg/m2.d.

RESULTS

Apnea hypopnea index (AHI) was 5.1 per hour (2.8-8.7) (normal 0-1 per hour). Of these, 2.8 per hour (1.5-5.4) were central apneas and the rest mainly hypopneas. Duration of apneas was 15.0 sec (13.0-28.0). AHI did not correlate with age and body mass index, but central apneas decreased with age (r = -0.34, P = 0.01). During 6 months of GH treatment, AHI did not significantly change from 4.8 (2.6-7.9) at baseline to 4.0 (2.7-6.2; P = 0.36). One patient died unexpectedly during a mild upper respiratory tract infection, although he had a nearly normal polysomnography.

CONCLUSIONS

PWS children have a high AHI, mainly due to central apneas. Six months of GH treatment does not aggravate the sleep-related breathing disorders in young PWS children. Our study also shows that monitoring during upper respiratory tract infection in PWS children should be considered.

Enhanced chemo-responsiveness in patients with sleep apnoea and end-stage renal disease

Although sleep apnoea is very common in patients with end-stage renal disease, the physiological mechanisms for this association have not yet been determined. The current authors hypothesised that altered respiratory chemo-responsiveness may play an important role. In total, 58 patients receiving treatment with chronic dialysis were recruited for overnight polysomnography. A modified Read rebreathing technique, which is used to assess basal ventilation, ventilatory sensitivity and threshold, was completed before and after overnight polysomnography. Patients were divided into apnoeic (n = 38; apnoea/hypopnoea index (AHI) 35+/-22 events.h(-1)) and nonapnoeic (n = 20; AHI 3+/-3 events.h(-1)) groups, with the presence of sleep apnoea defined as an AHI >10 events.h(-1). While basal ventilation and the ventilatory recruitment threshold were similar between groups, ventilatory sensitivity during isoxic hypoxia (partial pressure of oxygen (PO2) 6.65 kPa) and hyperoxia (PO2) 19.95 kPa) was significantly greater in apnoeic patients. Overnight changes in chemoreflex responsiveness were similar between groups. In conclusion, these data indicate that the responsiveness of both the central and peripheral chemoreflexes is augmented in patients with sleep apnoea and end-stage renal disease. Since increased ventilatory sensitivity to hypercapnia destabilises respiratory control, the current authors suggest this contributes to the pathogenesis of sleep apnoea in this patient population.