A high prevalence of sleep disordered breathing in men with mild symptomatic chronic heart failure due to left ventricular systolic dysfunction

BACKGROUND: Sleep disordered breathing (SDB) is common in severe chronic heart failure (CHF) and is associated with increased morbidity and mortality. The prevalence of SDB in mild symptomatic CHF is unknown. AIM: The aim of this study was to determine the prevalence and characteristics of SDB in male patients with NYHA class II symptoms of CHF. METHODS AND RESULTS: 55 male patients with mild symptomatic CHF underwent assessment of quality of life, echocardiography, cardiopulmonary exercise, chemoreflex testing and polysomnography. 53% of the patients had SDB. 38% had central sleep apnoea (CSA) and 15% had obstructive sleep apnoea. SDB patients had steeper VE/VCO(2) slope [median (inter-quartile range) 31.1 (28-37) vs. 28.1 (27-30) respectively; p=0.04], enhanced chemoreflexes to carbon dioxide during wakefulness [mean+/-sd: 2.4+/-1.6 vs. 1.5+/-0.7 %VE Max/mmHg CO(2) respectively; p=0.03], and significantly higher levels of brain natriuretic peptide and endothelin-1 compared to patients without SDB. No differences in left ventricular ejection fraction, percent predicted peak oxygen uptake, or symptoms of SDB were observed. CONCLUSIONS: A high prevalence of SDB was found in men with mild symptomatic CHF. Patients with SDB could not be differentiated by symptoms or by routine cardiac assessment making clinical diagnosis of SDB in CHF difficult.     

Sleep disturbances and insulin resistance

The causes and risk factors of insulin resistance remain insufficiently understood. After taking into account the important roles of adiposity, age, sex and race/ethnicity, up to 50% of the individual variability in insulin resistance remains unexplained. In recent years, evidence has accumulated to support a role for sleep disturbances, including insufficient sleep, poor sleep quality and insomnia, and obstructive sleep apnoea, as independent risk factors for the development and exacerbation of insulin resistance. The present review summarizes the evidence. We will start with a brief introduction to sleep and its disorders and then examine in succession the role of the three major types of sleep disturbances of modern society, namely insufficient sleep, poor sleep quality and/or insomnia and obstructive sleep apnoea. Insulin resistance is a hallmark of the polycystic ovary syndrome, the most common endocrine pathology in women, and the last section of this review will discuss the role of obstructive sleep apnoea in the insulin resistance and metabolic disturbances of polycystic ovary syndrome.     

Continuous positive airway pressure therapy in sleep apnoea

Sleep apnoea is associated with increased mortality and morbidity. The treatment goal is to reduce the neurocognitive and cardiovascular sequelae. CPAP therapy in sleep apnoea is discussed in two parts in the article. The first part will consider CPAP therapy in the more common form of sleep apnoea (i.e. obstructive or mixed sleep apnoea) and the second part will consider CPAP therapy in central sleep apnoea. Alternative positive airway pressure modalities are discussed. CPAP therapy has been extensively studied and it remains the mainstay of treatment in obstructive sleep apnoea, as it is still the most consistently efficacious and safe option. However, its major disadvantage is that it does not confer a cure to this disorder and hence therapy is generally life long with its usual treatment compliance problems. As such, there are continuous improvement strategies. The role of CPAP therapy in central sleep apnoea is more limited. There has been increasing data on the beneficial effect of CPAP on central sleep apnoea/Cheyne-Stokes respiration in congestive heart failure. Evidence for CPAP therapy in sleep apnoea has evolved significantly over the last decade. However, more research and publication of large-scale long-term randomized trials of treatment in sleep apnoea to assess patient-orientated outcomes and preferences are necessary.     

Nomogram to diagnosis of obstructive sleep apnoea-hypopnoea syndrome in high-risk Chinese adult patients

Introduction

Many scales are designed to screen for obstructive sleep apnoea-hypopnoea syndrome (OSAHS); however, there is a lack of an efficiently and easily diagnostic tool, especially for Chinese. Therefore, we conduct a cross-sectional study in China to develop and validate an efficient and simple clinical diagnostic model to help screen patients at risk of OSAHS.

Methods

This study based on 782 high-risk patients (aged >18 years) admitted to the Sleep Medicine department of the Sixth Affiliated Hospital, Sun Yat-sen University from 2015 to 2021. Totally 34 potential predictors were evaluated. We divided all patients into training and validation dataset to develop diagnostic model. The univariable and multivariable logistic regression model were used to build model and nomogram was finally built.

Results

Among 602 high-risk patients with median age of 46 (37, 56) years, 23.26% were women. After selecting using the univariate logistic model, 15 factors were identified. We further used the stepwise method to build the final model with five factors: age, BMI, total bilirubin levels, high Berlin score, and symptom of morning dry mouth or mouth breathing. The AUC was 0.780 (0.711, 0.848), with sensitivity of 0.848 (0.811, 0.885), specificity of 0.629 (0.509, 0.749), accuracy of 0.816 (0.779, 0.853). The discrimination ability had been verified in the validation dataset. Finally, we established a nomogram model base on the above final model.

Conclusion

We developed and validated a predictive model with five easily acquire factors to diagnose OSAHS patient in high-risk population with well discriminant ability. Accordingly, we finally build the nomogram model.     

Sleep-disordered breathing and glucose metabolism in hypertensive men: a population-based study

OBJECTIVES: Diabetes mellitus and obstructive sleep apnoea (OSA) are two prevalent medical problems. Both are strongly associated with obesity and hypertension. The aim of this study was to investigate whether the association between OSA and diabetes is entirely dependent on obesity in hypertensive men. DESIGN: A population-based study. SETTING: The municipality of Uppsala, Sweden. Subjects and methods. In 1994, 2668 men aged 40-79 years answered a questionnaire regarding snoring, sleep disturbances and somatic diseases. An age-stratified sample of 116 hypertensive men was selected for a whole-night sleep study. Twenty-five of them had diabetes, defined as reporting regular medical controls for diabetes or having a fasting blood glucose > or =6.1 mmol L(-1). RESULTS: The prevalence of severe OSA, defined as apnoea-hypopnoea index (AHI) > or =20 h(-1) was significantly higher in diabetic patients than in normoglycaemic subjects (36 vs. 14.5%, P < 0.05). The sample was divided into four groups based on the presence or absence of severe OSA and the presence or absence of central obesity, defined as waist-to-hip ratio (WHR) > or =1.0. In a logistic regression model with the non-OSA, WHR <1.0 as the reference group, the adjusted odds ratio (95% confidence interval) for diabetes was 11.8 (2.0-69.8) in the OSA, WHR > or =1.0 group, whilst it was 3.6 (0.9-14.8) in the non-OSA, WHR > or =1.0 group and 5.7 (0.3-112) in the OSA, WHR <1.0 group. In a linear regression model, after adjustment for WHR, there was a significant relationship between variables of sleep-disordered breathing and fasting insulin, glucose and haemoglobin A1c. CONCLUSIONS: We conclude that, in hypertensive men, although obesity is the main risk factor for diabetes, coexistent severe OSA may add to this risk. Sleep breathing disorders, independent of central obesity, may influence plasma insulin and glycaemia.     

Apnoeic–hypopnoeic episodes during obstructive sleep apnoea are associated with histological nonalcoholic steatohepatitis

Background: Nonalcoholic fatty liver disease (NAFLD) and obstructive sleep apnoea are associated with metabolic syndrome and atherosclerotic heart disease. This study evaluates the potential association between the NAFLD subtypes and a number of polysomnographical (PSG) parameters. Methods: This study included patients undergoing bariatric surgery with extensive clinical and histological data for whom complete PSG data before surgery were also available. Excess alcohol intake and other causes of liver disease were excluded. Apnoea, hypopnoea and apnoea–hypopnoea index (AHI) were calculated as described previously. Results: In this study, a total of 101 patients [77 nonalcoholic steatohepatitis (NASH) and 22 non‐NASH controls] with PSG data were included (age 42.9 ± 11.4 years, body mass index 51.6 ± 9.5 kg/m², fasting serum glucose 117.4 ± 53.4 mg/dl, fasting serum triglycerides 171.3 ± 82.9 mg/dl, 58% hypertension and 33% diabetes mellitus). Subjects with histological NASH had significantly lower lowest desaturation (77 vs. 85%, P=0.006), lower mean nocturnal oxygen saturation (91 vs. 93%, P=0.05), higher AHI (35 vs. 22, P=0.03), higher respiratory disturbance index (46 vs. 21, P=0.02) and higher alanine aminotransferase/aspartate aminotransferase ratio (1.4 vs. 1.3, P=0.05) compared with non‐NASH controls. In multivariate analysis, the lowest desaturation (P=0.04) was independently associated with histological NASH. Lowest desaturation and mean nocturnal oxygen saturation were significantly lower in subjects with fibrosis (76 vs. 85%, P=0.004 and 90.4 vs. 93.0%, P=0.02). Conclusions: Our results suggest that the frequent nocturnal hypoxic episodes in NAFLD patients may be a risk factor for developing NASH. Additional studies are needed to study the effect of optimizing sleep apnoea management on the outcomes of patients with NAFLD.     

Sudden death and sleeping history among Finnish men

An autopsy was performed in 460 consecutive cases of sudden death among 35- to 76-year-old men. The closest cohabiting individual known to each decreased subject was interviewed. Snoring history was obtained in 321 of the 371 interviews. In 86 cases there was a history of 'habitual' (almost always or always) snoring, and 88 men snored 'often'. The mean age of subjects was 55.4 years. The mean body mass index (BMI) was 26.3 kg m-2. Among the obese snorers (n = 82), apnoeas had been observed 'occasionally', 'often', or 'habitually' in 49 cases. Death was classified as cardiovascular in 186 (40.4%) cases. Cardiovascular cause of death was more common among those who snored habitually or often than among those who snored occasionally or never (P less than 0.05). 'Habitual' snorers died more often while sleeping (P less than 0.05). Habitual snoring was found to be a risk factor for morning death (P less than 0.01). The possibility of obstructive sleep apnoea as a cause of sudden death should at least be considered if the decreased is known to have been a habitual snorer.     

Sleep apnoea syndrome in Ramathibodi Hospital: clinical and polysomnographic baseline data

OBJECTIVE: The aim of this study was to determine clinical and baseline polysomnographic data on obstructive sleep apnoea (OSA) in Thai patients. This prospective study was performed at the Sleep Laboratory Center, Ramathibodi Hospital, Mahidol University, Thailand. METHODOLOGY: Ninety adult cases clinically suspected of having OSA were studied. The study included clinical, blood chemistry, electrocardiogram, chest radiograph, arterial blood gas, spirometry and full night polysomnography. RESULTS: Fifty-nine cases (65.6%) out of a total of 90 cases had an abnormal apnoea (i.e. apnoea index (AI) of 5 or more). The incidence of upper airway abnormality among cases with AI of 5 or more was 79.7% (47/59 cases). Among 59 patients with abnormal AI, associated medical problems comprised hypertension (n=22), obesity hypoventilation (n=9), hypothyroidism (n=4), chronic airflow obstruction (n=4), diabetes mellitus (n=3) and chronic renal failure (n=1). Obstructive sleep apnoea was present in all 59 cases. Central apnoea and mixed apnoea were rare. CONCLUSION: Symptoms and signs suggestive of OSA can lead to a high detection rate and confirmation of OSA by polysomnography. The OSA characteristics of Thai patients were similar to the patients in the Western world.