Obstructive sleep apnea and type 2 diabetes

The association between biomarker angiopoietin-like protein five and obstructive sleep apnea in patients undergoing bariatric surgery

PURPOSE

Obstructive sleep apnea (OSA) is prevalent in the bariatric population. OSA should be recognized in patients undergoing bariatric surgery preoperatively to prevent peri- and post-operative complications. Lipid metabolism-related biomarkers are associated with OSA. Triglyceride metabolism is, among others, regulated by angiopoietin-like protein five (ANGPTL5). We aimed to evaluate the level of ANGPTL5 in patients with OSA of different severity levels before and after bariatric surgery.

METHODS

We performed a single-center prospective cohort study including a consecutive series of patients who underwent bariatric surgery. We collected the clinical data, polysomnography (PSG) or polygraphy (PG) parameters, and plasma derived via venipuncture before and 6 to 12 months after surgery. Lipid profile, glucose levels, and ANGPTL5 levels were assessed. ANGPTL5 levels were measured using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

The study included 88 patients for analysis. The patients were divided into two subgroups: no or mild OSA (apnea-hypopnea index (AHI) < 15 events/hour, n = 57) and moderate-to-severe OSA (AHI ≥ 15 events/hour, n = 31). The ANGPTL5 level was higher in the moderate-to-severe OSA group (20.5 [15.6, 26.5] ng/mL) compared to the no or mild OSA group (16.3 [12.5, 19.4] ng/mL) (p = 0.008). A significant positive correlation was observed between ANGPTL5 and AHI (ρ = 0.256, p = 0.017), apnea index (AI) (ρ = 0.318, p = 0.003), and triglyceride levels (ρ = 0.240, p = 0.025). ANGPTL5 levels were reduced significantly after bariatric surgery in both moderate-to-severe OSA (15.6 [10.3, 18.7] ng/mL) and no or mild OSA (13.4 [9.2, 15.8] ng/mL) groups, though to a lower level in the group without or mild OSA. Post-surgery, the significant positive correlation between ANGPTL5 and AHI (ρ = 0.210, p = 0.047), AI (ρ = 0.230, p = 0.034), and triglyceride (ρ = 0.397, p < 0.001) remained.

CONCLUSION

The data showed increased levels of ANGPTL5 in patients with moderate-to-severe OSA. Both AHI and ANGPTL5 levels decreased significantly after bariatric surgery. We also report an association between ANGPTL5 levels and OSA severity.

Risk of diabetes in patients with sleep apnea: comparison of surgery versus CPAP in a long-term follow-up study

This study aimed to obtain a comprehensive view of the risk of developing diabetes in patients with obstructive sleep apnea (OSA) and to compare this risk between patients receiving continuous positive airway pressure (CPAP) therapy versus upper airway surgery (UAS). We used local and the global-scale federated data research network TriNetX to obtain access to electronic medical records, including those for patients diagnosed with OSA, from health-care organizations (HCOs) worldwide. Using propensity score matching and the score-matched analyses of data for 5 years of follow-up, we found that patients who had undergone UAS had a lower risk of developing diabetes than those who used CPAP (risk ratio 0.415, 95% confidence interval (CI) 0.349-0.493). The risk for newly diagnosed diabetes patients showed a similar pattern (hazard ratio 0.382; 95% CI 0.317-0.459). Both therapies seem to protect against diabetes (Risk 0.081 after UAS vs. 0.195 after CPAP). Analysis of the large data sets collected from HCOs in Europe and globally lead us to conclude that, in patients with OSA, UAS can prevent the development of diabetes better than CPAP.

Upper Airway Stimulation Therapy Effect on Blood Pressure

OBJECTIVE

Upper airway stimulation (UAS) therapy has become increasingly utilized to treat obstructive sleep apnea, which is an independent risk factor for the development of hypertension. This study examines the impact of this therapy on blood pressure (BP).

STUDY DESIGN

Retrospective cross-sectional cohort study.

SETTING

Tertiary center, Military Health System.

METHODS

Patients who underwent UAS implantation at Brooke Army Medical Center between July 2015 and July 2020 were included if they used their device for at least 25 h/wk. Pre- and postoperative systolic BP, diastolic blood pressure (DBP), calculated mean arterial pressure (MAP), and the apnea-hypopnea index (AHI) were compared using paired t test or Wilcoxon's signed-rank test.

RESULTS

Thirty patients met the inclusion criteria. The median age was 60, and the median body mass index was 29.9 kg/m² . The mean time between pre- and postoperative BP measurements was 11.6 months. AHI decreased from 35.1 to 16.5 events/h (p < .001). DBP decreased from 78.5 (73.8, 85.0) to 74.5 mm Hg (68.8, 81.3), with a mean difference of -3.7 mm Hg (p = .002). MAP decreased from 94.8 (89.6, 100.6) to 90.2 mm Hg (84.3, 100.0), with a mean difference of -3.7 mm Hg (p = .004).

CONCLUSION

UAS therapy was associated with a significant reduction in DBP, MAP, and AHI. These reductions in BP could potentially lead to favorable decreases in cardiovascular morbidity.

Sleep Disturbances in Neurological Disease: A Target for Intervention

Sleep is a biological function required for neurological and general health, but a significant and under-recognized proportion of the population has disturbed sleep. Here, we briefly overview the biology of sleep, sleep requirements over the lifespan, and common sleep disorders. We then turn our attention to five neurological diseases that significantly contribute to global disease burden and neurology practice makeup: epilepsy, headache, ischemic stroke, Parkinson's disease, and Alzheimer's disease. For each disease, we review evidence that sleep disturbances contribute to disease risk and severity and discuss existing data that addressing sleep disturbances may have disease-modifying effects. We provide recommendations derived from the literature and existing clinical guidelines to facilitate the evaluation and management of sleep disturbances within the context of each neurological disease. Finally, we synthesize identified needs and commonalities into future directions for the field and practical sleep-related recommendations for physicians caring for patients at risk for or currently suffering from neurological disease.

Sleep dysregulation in sympathetic-mediated diseases: implications for disease progression

The autonomic nervous system (ANS) plays an important role in the coordination of several physiological functions including sleep/wake process. Significant changes in ANS activity occur during wake-to-sleep transition maintaining the adequate cardiorespiratory regulation and brain activity. Since sleep is a complex homeostatic function, partly regulated by the ANS, it is not surprising that sleep disruption trigger and/or evidence symptoms of ANS impairment. Indeed, several studies suggest a bidirectional relationship between impaired ANS function (i.e. enhanced sympathetic drive), and the emergence/development of sleep disorders. Furthermore, several epidemiological studies described a strong association between sympathetic-mediated diseases and the development and maintenance of sleep disorders resulting in a vicious cycle with adverse outcomes and increased mortality risk. However, which and how the sleep/wake control and ANS circuitry becomes affected during the progression of ANS-related diseases remains poorly understood. Thus, understanding the physiological mechanisms underpinning sleep/wake-dependent sympathetic modulation could provide insights into diseases involving autonomic dysfunction. The purpose of this review is to explore potential neural mechanisms involved in both the onset/maintenance of sympathetic-mediated diseases (Rett syndrome, congenital central hypoventilation syndrome, obstructive sleep apnoea, type 2 diabetes, obesity, heart failure, hypertension, and neurodegenerative diseases) and their plausible contribution to the generation of sleep disorders in order to review evidence that may serve to establish a causal link between sleep disorders and heightened sympathetic activity.

Obstructive Sleep Apnea Affects Lacrimal Gland Function

Purpose

To determine the effect of obstructive sleep apnea syndrome (OSA) on lacrimal gland function and its mechanism.

Methods

Male mice aged seven to eight weeks were housed in cages with cyclic intermittent hypoxia to mimic OSA, and the control group was kept in a normal environment. Slit-lamp observation, fluorescein staining, and corneal sensitivity detection are used to assess cornea changes. Tear secretion was detected by phenol red cotton thread, and the pathological changes of lacrimal gland were observed by hematoxylin and eosin staining, oil red O staining, cholesterol and triglyceride kits, immunofluorescence staining, immunohistochemical staining, real-time polymerase chain reaction, transmission electron microscopy, and Western blot.

Results

Studies revealed a decreased tear secretion, corneal epithelial defects and corneal hypersensitivity. Myoepithelial cell damage, abnormal lipid accumulation, reduced cell proliferation, increased apoptosis and inflammatory cell infiltration in the lacrimal gland were also seen. Hifα and NF-κB signaling pathways, moreover, were activated, while Pparα was downregulated, in the lacrimal glands of OSA mice. Fenofibrate treatment significantly alleviated pathological changes of the lacrimal gland induced by OSA.

Conclusion

OSA disturbs the Hifα/Pparα/NF-κB signaling axis, which affects lacrimal gland structure and function and induces dry eye.

Polysomnographic Phenotypes of Obstructive Sleep Apnea and Incident Type 2 Diabetes: Results from the DREAM Study

Rationale: Obstructive sleep apnea (OSA) is associated with cardiovascular disease and incident type 2 diabetes (T2DM). Seven OSA phenotypes, labeled on the basis of their most distinguishing polysomnographic features, have been shown to be differentially associated with incident cardiovascular disease. However, little is known about the relevance of polysomnographic phenotypes for the risk of T2DM. Objectives: To assess whether polysomnographic phenotypes are associated with incident T2DM and to compare the predictive value of baseline polysomnographic phenotypes with the Apnea-Hypopnea Index (AHI) for T2DM. Methods: The study included 840 individuals without baseline diabetes from a multisite observational U.S. veteran cohort who underwent OSA evaluation between 2000 and 2004, with follow-up through 2012. The primary outcome was incident T2DM, defined as no diagnosis at baseline and a new physician diagnosis confirmed by fasting blood glucose >126 mg/dL during follow-up. Relationships between the seven polysomnographic phenotypes (1. mild, 2. periodic limb movements of sleep [PLMS], 3. non-rapid eye movement and poor sleep, 4. rapid eye movement and hypoxia, 5. hypopnea and hypoxia, 6. arousal and poor sleep, and 7. combined severe) and incident T2DM were investigated using Cox proportional hazards regression and competing risk regression models with and without adjustment for baseline covariates. Likelihood ratio tests were conducted to compare the predictive value of the phenotypes with the AHI. Results: During a median follow-up period of 61 months, 122 (14.5%) patients developed incident T2DM. After adjustment for baseline sociodemographics, fasting blood glucose, body mass index, comorbidities, and behavioral risk factors, hazard ratios among persons with "hypopnea and hypoxia" and "PLMS" phenotypes as compared with persons with "mild" phenotype were 3.18 (95% confidence interval [CI], 1.53-6.61] and 2.26 (95% CI, 1.06-4.83) for incident T2DM, respectively. Mild OSA (5 ⩽ AHI < 15) (vs. no OSA) was directly associated with incident T2DM in both unadjusted and multivariable-adjusted regression models. The addition of polysomnographic phenotypes, but not AHI, to known T2DM risk factors greatly improved the predictive value of the computed prediction model. Conclusions: Polysomnographic phenotypes "hypopnea and hypoxia" and "PLMS" independently predict risk of T2DM among a predominantly male veteran population. Polysomnographic phenotypes improved T2DM risk prediction comared with the use of AHI.

Honokiol: A review of its pharmacological potential and therapeutic insights

BACKGROUND

Honokiol is a pleiotropic compound which been isolated from Magnolia species such as Magnolia grandiflora and Magnolia dealbata. Magnolia species Magnolia grandiflora is used in traditional medicine for the treatment of various diseases.

PURPOSE

The objective of this review is to summarize the pharmacological potential and therapeutic insights of honokiol.

STUDY DESIGN

Honokiol has been specified as a novel alternative to treat various disorders such as liver cancer, neuroprotective, anti-spasmodic, antidepressant, anti-tumorigenic, antithrombotic, antimicrobial, analgesic properties and others. Therefore, this study designed to represent the in-depth therapeutic potential of honokiol.

METHODS

Literature searches in electronic databases, such as Web of Science, Science Direct, PubMed, Google Scholar, and Scopus, were performed using the keywords 'Honokiol', 'Health Benefits' and 'Therapeutic Insights' as the keywords for primary searches and secondary search terms were used as follows: 'Anticancer', 'Oxidative Stress', 'Neuroprotective', 'Antimicrobial', 'Cardioprotection', 'Hepatoprotective', 'Anti-inflammatory', 'Arthritis', 'Reproductive Disorders'.

RESULTS

This promising bioactive compound presented an wide range of therapeutic and biological activities which include liver cancer, neuroprotective, anti-spasmodic, antidepressant, anti-tumorigenic, antithrombotic, antimicrobial, analgesic properties, and others. Its pharmacokinetics has been established in experimental animals, while in humans, this is still speculative. Some of its mechanism for exhibiting its pharmacological effects includes apoptosis of diseased cells, reduction in the expression of defective proteins like P-glycoproteins, inhibition of oxidative stress, suppression of pro-inflammatory cytokines (TNF-α, IL-10 and IL-6), amelioration of impaired hepatic enzymes and reversal of morphological alterations, among others.

CONCLUSION

All these actions displayed by this novel compound could make it serve as a lead in the formulation of drugs with higher efficacy and negligible side effects utilized in the treatment of several human diseases.

Targeted Metabolomics Analysis on Obstructive Sleep Apnea Patients after Multilevel Sleep Surgery

BACKGROUND

Obstructive sleep apnea (OSA) is caused by partial or complete obstruction of the upper airways. Corrective surgeries aim at removing obstructions in the nasopharynx, oropharynx, and hypopharynx. OSA is associated with an increased risk of various metabolic diseases. Our objective was to evaluate the effect of surgery on the plasma metabolome.

METHODS

This study included 39 OSA patients who underwent Multilevel Sleep Surgery (MLS). Clinical and anthropometric measures were taken at baseline and five months after surgery.

RESULTS

The mean Apnea-Hypopnea Index (AHI) significantly dropped from 22.0 ± 18.5 events/hour to 8.97 ± 9.57 events/hour (p-Value < 0.001). Epworth's sleepiness Score (ESS) dropped from 12.8 ± 6.23 to 2.95 ± 2.40 (p-Value < 0.001), indicating the success of the surgery in treating OSA. Plasma levels of metabolites, phosphocholines (PC) PC.41.5, PC.42.3, ceremide (Cer) Cer.44.0, and triglyceride (TG) TG.53.6, TG.55.6 and TG.56.8 were decreased (p-Value < 0.05), whereas lysophosphatidylcholines (LPC) 20.0 and PC.39.3 were increased (p-Value < 0.05) after surgery.

CONCLUSION

This study highlights the success of MLS in treating OSA. Treatment of OSA resulted in an improvement of the metabolic status that was characterized by decreased TG, PCs, and Cer metabolites after surgery, indicating that the success of the surgery positively impacted the metabolic status of these patients.

Inspiratory Muscle Training in Obstructive Sleep Apnea Associating Diabetic Peripheral Neuropathy: A Randomized Control Study

Objective

This work is aimed at assessing the effects of inspiratory muscle training on lung functions, inspiratory muscle strength, and aerobic capacity in diabetic peripheral neuropathy (DPN) patients with obstructive sleep apnea (OSA).

Methods

A randomized control study was performed on 55 patients diagnosed with DPN and OSA. They were assigned to the training group (IMT, n = 28) and placebo training group (P-IMT, n = 27). Inspiratory muscle strength, lung functions, and aerobic capacity were evaluated before and after 12 weeks postintervention. An electronic inspiratory muscle trainer was conducted, 30 min a session, three times a week for 12 consecutive weeks.

Results

From seventy-four patients, 55 have completed the study program. A significant improvement was observed in inspiratory muscle strength (p < 0.05) in the IMT group while no changes were observed in the P-IMT group (p > 0.05). No changes were observed in the lung function in the two groups (p > 0.05). Also, VO₂max and VCO₂max changed significantly after training in the IMT group (p < 0.05) while no changes were observed in the P-IMT group (p > 0.05). Other cardiopulmonary exercise tests did not show any significant change in both groups (p > 0.05).

Conclusions

Based on the outcomes of the study, it was found that inspiratory muscle training improves inspiratory muscle strength and aerobic capacity without a notable effect on lung functions for diabetic patients suffering from DPN and OSA.

Sleep Apnea, Obesity, and Disturbed Glucose Homeostasis: Epidemiologic Evidence, Biologic Insights, and Therapeutic Strategies

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA), obesity, and disturbed glucose homeostasis are usually considered distinct clinical condition, although they are tightly related to each other. The aim of our manuscript is to provide an overview of the current evidence on OSA, obesity, and disturbed glucose homeostasis providing epidemiologic evidence, biological insights, and therapeutic strategies.

RECENT FINDINGS

The mechanisms hypothesized to be involved in this complex interplay are the following: (1) "direct weight-dependent" mechanisms, according to which fat excess compromises respiratory mechanics, and (2) "indirect weight-dependent" mechanisms such as hyperglycemia, insulin resistance and secondary hyperinsulinemia, leptin resistance and other hormonal dysregulations frequently found in subjects with obesity, type 2 diabetes, and/or sleep disorders. Moreover, the treatment of each of these clinical conditions, through weight loss induced by diet or bariatric surgery, the use of anti-obesity or antidiabetic drugs, and continuous positive airway pressure (CPAP), seems to positively influence the others. These recent data suggest not only that there are multiple connections among these diseases but also that treating one of them may result in an improvement of the others.

Prevalence of Sleep Apnea in Patients with Carotid Artery Stenosis

Obstructive sleep apnea (OSA) is a common disease affecting about 13% of men and 6% of women, usually having severe cardiovascular sequalae. OSA is responsible for the systemic inflammatory response and oxidative stress and results in endothelial injury being a risk factor for atherosclerosis. The aim of this study was to estimate the prevalence of OSA among patients with severe carotid artery stenosis. Fifty-five patients (F/M-24/31, mean age 70 ± 7 years, body mass index 28.3 ± 6.3 kg/m²) were enrolled into the study. The patients were qualified for elective surgical treatment of carotid artery stenosis. Polysomnography was performed in all patients the night before surgery. Thirty-six patients underwent surgical endarterectomy and nineteen patients underwent carotid artery stenting. Sleep apnea was diagnosed in 44 (80%) of all patients. The mean apnea-hypopnea index (AHI) was 14.5 ± 12.9. The OSA severity distribution was as follows: 22 mild, 16 moderate, and 6 severe cases. We found that the percentage of carotid endarterectomies was the greatest in mild and moderate OSA. It was approximately twofold greater than that in non-OSA patients. Carotid artery stenting was performed in nearly half of the patients in each of these groups. We conclude that OSA is highly prevalent in patients with carotid artery stenosis scheduled for carotid surgery. Nonetheless, the exact pathogenetic mechanisms underlying mutual interaction between OSA and vascular wall damage remain elusive. OSA is not routinely diagnosed among patients with advanced atherosclerosis. The study results might be an argument for performing polysomnography in patients with carotid artery stenosis.

Prevalence of self-reported sleep problems amongst adults with obstructive airway disease in the NHANES cohort in the United States

RATIONALE

Sleep and respiratory problems are common in adults in the USA. However, sleep problems often remain undiagnosed in patients with obstructive airway diseases (OADs). This study was designed to examine the association between sleep problems and different categories of OAD amongst US adults.

METHODS

We conducted an observational, cross-sectional study using a nationally representative sample of the US civilian non-institutionalized population from 2007 to 2008 National Health and Nutritional Examination Survey (NHANES). A total of 3204 study participants aged ≥35 years were stratified into four groups, using a self-reported history of asthma and data from spirometry: asthma-COPD overlap (ACO) (n = 70, 2.2%), asthma (n = 168, 5.2%), chronic obstructive pulmonary disease (COPD) (n = 412, 12.8%), and those without any OAD (normal) (n = 2554, 79.7%). After characterizing the baseline demographics and health status of the four groups, multivariate logistic regression analysis was performed to estimate the likelihood of sleep problems in adults after adjusting for age, gender, body mass index, smoking, alcohol, obstructive sleep apnea syndrome (OSAS), depression, and diabetes. The index sample was the normal group. Sleep problems were defined as any complaints which affect or involve sleep.

RESULTS

The participants with COPD were older (62.0 ± 11.7 years) as compared to ACO (59.1 ± 11.3 years), asthma (53.6 ± 11.3), and normal groups (53.8 ± 12.1) (p < 0.0001). Comparing baseline characteristics between the four groups, there were significant associations between OAD status and sleep problems including inadequate sleep, sleep-onset insomnia, snoring, frequent trouble sleeping, nocturnal arousals, early morning awakenings, fatigue, daytime sleepiness, use of prescription medication for sleep, leg jerks, leg cramps, difficulty in concentration, and difficulty in remembering things when tired. The multivariate logistic regression models evaluating the prevalence of sleep problems in individual OADs showed a stronger association between asthma and sleep problems as compared to COPD and ACO and sleep disorders.

CONCLUSION

All OADs are associated with a higher prevalence of sleep problems. There is a stronger association between asthma and sleep problems as compared to COPD and ACO. We speculate that the nocturnal burden of asthma contributes to sleep problems. Our results suggest that adults with OAD should be aggressively screened for sleep problems.

Metabolic Consequences of Obstructive Sleep Apnea Especially Pertaining to Diabetes Mellitus and Insulin Sensitivity

Obstructive sleep apnea (OSA) and diabetes has been known to be closely related to each other and both diseases impact highly on the public health. There are many evidence of reports that OSA is associated with diabetes with a bidirectional correlation. A possible causal mechanism of OSA to diabetes is intermittent hypoxemia and diabetes to OSA is microvascular complication. However, OSA and diabetes have a high prevalence rate in public and shares the common overlap characteristic and risk factors such as age, obesity, and metabolic syndrome that make it difficult to establish the exact pathophysiologic mechanism between them. In addition, studies demonstrating that treatment of OSA may help prevent diabetes or improve glycemic control have not shown convincing result but have become a great field of interest research. This review outlines the bidirectional correlation between OSA and diabetes and explore the pathophysiologic mechanisms by approaching their basic etiologies.

Cerebral Hemodynamics in Sleep Apnea and Actigraphy-Determined Sleep Duration in a Sample of the Hispanic Community Health Study/ Study of Latinos

STUDY OBJECTIVES

We sought to evaluate cerebral hemodynamics in obstructive sleep apnea (OSA) and actigraphy-defined short sleep duration using transcranial Doppler ultrasound (TCD) blood flow velocity in a subsample of Hispanics/Latinos without stroke and cardiovascular disease.

METHODS

The sample consisted of consecutive participants at the Miami site of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) with overnight home sleep testing and 7 days of wrist actigraphy in the Sueño sleep ancillary study. Ninety-five participants had sleep data and TCD determined cerebral hemodynamics. We evaluated the association between OSA (apnea-hypopnea index [AHI] ≥ 5 events/h) and short sleep duration (< 6.8 hours; sample median) with cerebral blood flow velocities (CBFV) and pulsatility index (PI) for the middle cerebral (MCA) and basilar arteries (BA).

RESULTS

Median age was 48 years (range 20-64) with 71% females. Twenty-eight percent of the sample had OSA (AHI ≥ 5 events/h) with median AHI of 10.0 (range 5.0-51.7) events/h. In unadjusted analyses, participants with OSA had lower median CBFV in the BA (30.5 cm/s [interquartile range:10.2] versus 39.4 cm/s [13.3] P < .05), but not the MCA, whereas short sleepers had higher median vascular resistance in the MCA (PI = 0.92 [0.18] versus 0.86 [0.14] P < .05) and BA (PI = 1.0 [0.17] versus 0.93 [0.24] P < .05). After full adjustment, OSA was associated with decreased CBFV (β [SE] = -5.1 [2.5] P < .05) in the BA. Short sleep was associated with increased PI (β [SE] = 0.05 [0.02] P < .05) in the MCA.

CONCLUSIONS

In this sample of Hispanic/Latinos, OSA was associated with decreased daytime blood flow velocity in the BA, whereas actigraphy-defined short sleep duration was associated with increased cerebrovascular pulsatility in the MCA.

Sleep disturbances in diabetic peripheral neuropathy patients: a clinical and polysomnographic study

Background

Disordered sleep breathing is a common complication of diabetic peripheral neuropathy (DPN) manifested by excessive daytime sleepiness, morning headache, morning dizziness, cognitive decline, and mood changes.

Methods

This study was performed on 30 non-obese type 2 diabetic patients; 20 with clinically evident DPN and 10 without. Ten age-, sex-, and body mass index-matched healthy control subjects were also included. Patients and control were subjected to history taking, neurological examination, glycated hemoglobin, and clinical assessment of the sensori-motor manifestations by the neuropathy symptom score and neuropathy disability score. The autonomic nervous system was evaluated clinically by the systolic blood pressure response to standing and heart rate response to each of standing, Valsalva, and deep breath. Finally, sleep was assessed by one-night polysomnogram (PSG) followed by multiple sleep latency test in the next day.

Results

The study showed significant increase in sleep apnea syndromes in diabetic peripheral neuropathy patients compared to diabetic neuropathy free patients and healthy control (p < 0.0001). The sleep apnea was mainly obstructive and to a little extent mixed (obstructive/central) sleep apnea. The severity of sleep PSG abnormalities was positively correlated with the severities of sensory, motor, and autonomic manifestations.

Conclusions

Non-obese type 2 diabetic patients complicated by peripheral neuropathy especially those having dysautonomia are at increased risk of developing sleep disordered breathing resulting in their excessive daytime sleepiness, decreased productivity, and poor glycemic control.

The Bidirectional Relationship Between Obstructive Sleep Apnea and Metabolic Disease

Obstructive sleep apnea (OSA) is a common sleep disorder, effecting 17% of the total population and 40-70% of the obese population (1, 2). Multiple studies have identified OSA as a critical risk factor for the development of obesity, diabetes, and cardiovascular diseases (3-5). Moreover, emerging evidence indicates that metabolic disorders can exacerbate OSA, creating a bidirectional relationship between OSA and metabolic physiology. In this review, we explore the relationship between glycemic control, insulin, and leptin as both contributing factors and products of OSA. We conclude that while insulin and leptin action may contribute to the development of OSA, further research is required to determine the mechanistic actions and relative contributions independent of body weight. In addition to increasing our understanding of the etiology, further research into the physiological mechanisms underlying OSA can lead to the development of improved treatment options for individuals with OSA.

Partial reversal of color vision impairment in type 2 diabetes associated with obstructive sleep apnea

Objective: Tritan anomaly is a known acquired color defect seen in diabetic patients, with or without the evidence of clinical signs of diabetic retinopathy (DR). We report a case of a 45-year-old diabetic patient with tritan pattern color defect associated with obstructive sleep apnea and its partial reversal with continuous positive airway pressure (CPAP) ventilation.

Methods: A 45-year-old male with diabetes, wildlife photographer by profession, presented with specific complaints of seeing all objects in the surrounding with a greenish tinge in both the eyes. He underwent a comprehensive eye examination including Farnsworth-Munsel 100 (FM 100) hue test, multifocal electroretinogram, microperimetry, spectral domain optical coherence tomography (SDOCT), and arterial oxygen saturation.

Results: The subject was found to have a low arterial oxygen saturation (PaO2) of 86%. He was then advised inhalation of 100% oxygen for 15 min, following which he reported improvement in his visual symptoms. FM 100, OCT, and microperimetry were repeated after oxygenation. He was referred to a specialty hospital for further evaluation of the cause for reduced blood oxygen saturation and was further advised for sleep study, where he was diagnosed to have obstructive sleep apnea (OSA) with an apnea-hypopnea index of 20.9.

Conclusion: The subject was advised weight loss measures and oral application of continuous positive airway pressure. Since then, he is under our regular follow-up and has never experienced or complained of any color vision problems. This case report highlights the presence of associated systemic disorders like obstructive sleep apnea in individuals with diabetes that can present with color vision problems.

Sleep Disturbances as a Risk Factor for Stroke

Sleep, a vital process of human being, is carefully orchestrated by the brain and consists of cyclic transitions between rapid eye movement (REM) and non-REM (NREM) sleep. Autonomic tranquility during NREM sleep is characterized by vagal dominance and stable breathing, providing an opportunity for the cardiovascular-neural axis to restore homeostasis, in response to use, distress or fatigue inflicted during wakefulness. Abrupt irregular swings in sympathovagal balance during REM sleep act as phasic loads on the resting cardiovascular system. Any causes of sleep curtailment or fragmentation such as sleep restriction, sleep apnea, insomnia, periodic limb movements during sleep, and shift work, not only impair cardiovascular restoration but also impose a stress on the cardiovascular system. Sleep disturbances have been reported to play a role in the development of stroke and other cardiovascular disorders. This review aims to provide updated information on the role of abnormal sleep in the development of stroke, to discuss the implications of recent research findings, and to help both stroke clinicians and researchers understand the importance of identification and management of sleep pathology for stroke prevention and care.

Increased Level of Angiopoietin Like Proteins 4 and 8 in People With Sleep Apnea

Objective: Obstructive sleep apnea (OSA) is a sleep disorder caused by the complete or partial obstruction of the upper airways. The worldwide prevalence of OSA is increasing due to its close association with obesity epidemic and multiple health complications, such as hypertension, cardiovascular disease, and Type 2 diabetes. Angiopoietin-like protein (ANGPTL)-4 and ANGPTL8 (betatrophin) have been suggested to play a role in the development of these diseases through their role in regulating the metabolism of plasma lipid molecules. This study was designed to evaluate ANGPTL4 and 8 levels in an OSA group and a control group to clarify the effect of OSA on ANGPTL4 and 8 levels. Methods: In total, 74 subjects were enrolled in this study, including 22 age- and body mass index (BMI)-matched controls with the Apnea Hypopnea Index (AHI) score of <5 events/h and 52 subjects with an AHI score of >5 events/h. Sleep apnea was assessed using a portable sleep test. ANGPTL4 and 8 levels were measured in plasma samples using enzyme-linked immunosorbent assay. Results: Mean AHI score (2.5 ± 1.6) in the control group was significantly lower than that in the OSA group (22.9 ± 17.9; p < 0.0001). Leptin, interleukin-(IL) 6, insulin, and HOMA-IR values were higher in the OSA group than in the control group. ANGPTL8 level was higher in the OSA group (1130.0 ± 108.61 pg/mL) than in the control group (809.39 ± 108.78 pg/mL; p = 0.041). Similarly, ANGPTL4 was higher in the OSA group (179.26 ± 12.89 ng/mL) than in the control group (142.63 ±7.99 ng/mL; p = 0.018). Conclusion: Our findings demonstrate that ANGPTL4 and 8 levels were increased in subjects with OSA, suggesting that the upregulation of these lipid metabolism regulators might play a role in lipid dysregulation observed in people with OSA.

Interactions between and Shared Molecular Mechanisms of Diabetic Peripheral Neuropathy and Obstructive Sleep Apnea in Type 2 Diabetes Patients

Type 2 diabetes (T2D) accounts for about 90% of all diabetes patients and incurs a heavy global public health burden. Up to 50% of T2D patients will eventually develop neuropathy as T2D progresses. Diabetic peripheral neuropathy (DPN) is a common diabetic complication and one of the main causes of increased morbidity and mortality of T2D patients. Obstructive sleep apnea (OSA) affects over 15% of the general population and is associated with a higher prevalence of T2D. Growing evidence also indicates that OSA is highly prevalent in T2D patients probably due to diabetic peripheral neuropathy. However, the interrelations among diabetic peripheral neuropathy, OSA, and T2D hitherto have not been clearly elucidated. Numerous molecular mechanisms have been documented that underlie diabetic peripheral neuropathy and OSA, including oxidative stress, inflammation, endothelin-1, vascular endothelial growth factor (VEGF), accumulation of advanced glycation end products, protein kinase C (PKC) signaling, poly ADP ribose polymerase (PARP), nitrosative stress, plasminogen activator inhibitor-1, and vitamin D deficiency. In this review, we seek to illuminate the relationships among T2D, diabetic peripheral neuropathy, and OSA and how they interact with one another. In addition, we summarize and explain the shared molecular mechanisms involved in diabetic peripheral neuropathy and OSA for further mechanistic investigations and novel therapeutic strategies for attenuating and preventing the development and progression of diabetic peripheral neuropathy and OSA in T2D.

Up-regulation of selenoprotein P and HIP/PAP mRNAs in hepatocytes by intermittent hypoxia via down-regulation of miR-203

Sleep apnea syndrome is characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia [IH]) and is a risk factor for insulin resistance/type 2 diabetes. However, the mechanisms linking IH stress and insulin resistance remain elusive. We exposed human hepatocytes (JHH5, JHH7, and HepG2) to experimental IH or normoxia for 24 h, measured mRNA levels by real-time reverse transcription polymerase chain reaction (RT-PCR), and found that IH significantly increased the mRNA levels of selenoprotein P (SELENOP) — a hepatokine — and hepatocarcinoma-intestine-pancreas/pancreatitis-associated protein (HIP/PAP) — one of REG (Regenerating gene) family. We next investigated promoter activities of both genes and discovered that they were not increased by IH. On the other hand, a target mRNA search of micro RNA (miRNA) revealed that both mRNAs have a potential target sequence for miR-203. The miR-203 level of IH-treated cells was significantly lower than that of normoxia-treated cells. Thus, we introduced miR-203 inhibitor and a non-specific control RNA (miR-203 inhibitor NC) into HepG2 cells and measured the mRNA levels of SELENOP and HIP/PAP. The IH-induced expression of SELENOP and HIP/PAP was abolished by the introduction of miR-203 inhibitor but not by miR-203 inhibitor NC. These results demonstrate that IH stress up-regulates the levels of SELENOP in human hepatocytes to accelerate insulin resistance and up-regulates the levels of HIP/PAP mRNAs to proliferate such hepatocytes, via the miR-203 mediated mechanism.

Obstructive sleep apnea in Type 2 diabetes and impact of continuous positive airway pressure therapy on glycemic control

BACKGROUND

Obstructive sleep apnea (OSA) and type 2 diabetes mellitus (T2DM) are two interacting epidemics both with high prevalence and morbidity. Both epidemiologic and clinical studies suggest that the majority of patients with T2DM also have OSA and untreated OSA in these patients results in poor glycemic control leading to acceleration of diabetes-related complications.

OBJECTIVES

To assess the prevalence and severity of OSA in T2DM patients and to assess the impact of OSA treatment on presenting symptoms and hemoglobin A1c (HbA1c).

METHODS

We performed polysomnography (PSG) studies and measured HbA1c in 62 consecutive patients with T2DM that were referred from various subspecialty clinics from July 2011 to August 2013.

RESULTS

In our 62 diabetic patients, 59 (95.2%) had abnormal PSG. Based on Apnea-Hypopnea Index (AHI) score, 3 (5.1%) patients had mild, 28 (47.5%) had moderate, and 28 (47.5%) had severe OSA. The mean AHI of diabetic patients was significantly more than nondiabetic patients, i.e., 25.7 versus 19.7 (P = 0.001). Variables that significantly correlated with the presence of OSA include age, gender, body mass index (BMI), hypertension, diabetes, and cardiovascular disease (P < 0.05); however, on logistic regression only BMI, hypertension, and nocturia correlated with OSA. Overall, 59% of diabetic patients showed improvement in their glycemic control as measured by HbA1c with continuous positive airway pressure (CPAP) treatment. Significant, moderate, and mild categories of treatment response were respectively observed in 7%, 20%, and 32% of patients.

CONCLUSION

Treatment of OSA with CPAP reduces HbA1c in a significant number of diabetics.

Glucose intolerance associated with hypoxia in people living at high altitudes in the Tibetan highland

OBJECTIVES

To clarify the association between glucose intolerance and high altitudes (2900-4800 m) in a hypoxic environment in Tibetan highlanders and to verify the hypothesis that high altitude dwelling increases vulnerability to diabetes mellitus (DM) accelerated by lifestyle change or ageing.

DESIGN

Cross-sectional epidemiological study on Tibetan highlanders.

PARTICIPANTS

We enrolled 1258 participants aged 40-87 years. The rural population comprised farmers in Domkhar (altitude 2900-3800 m) and nomads in Haiyan (3000-3100 m), Ryuho (4400 m) and Changthang (4300-4800 m). Urban area participants were from Leh (3300 m) and Jiegu (3700 m).

MAIN OUTCOME MEASURE

Participants were classified into six glucose tolerance-based groups: DM, intermediate hyperglycaemia (IHG), normoglycaemia (NG), fasting DM, fasting IHG and fasting NG. Prevalence of glucose intolerance was compared in farmers, nomads and urban dwellers. Effects of dwelling at high altitude or hypoxia on glucose intolerance were analysed with the confounding factors of age, sex, obesity, lipids, haemoglobin, hypertension and lifestyle, using multiple logistic regression.

RESULTS

The prevalence of DM (fasting DM)/IHG (fasting IHG) was 8.9% (6.5%)/25.1% (12.7%), respectively, in all participants. This prevalence was higher in urban dwellers (9.5% (7.1%)/28.5% (11.7%)) and in farmers (8.5% (6.1%)/28.5% (18.3%)) compared with nomads (8.2% (5.7%)/15.7% (9.7%)) (p=0.0140/0.0001). Dwelling at high altitude was significantly associated with fasting IHG+fasting DM/fasting DM (ORs for >4500 and 3500-4499 m were 3.59/4.36 and 2.07/1.76 vs <3500 m, respectively). After adjusting for lifestyle change, hypoxaemia and polycythaemia were closely associated with glucose intolerance.

CONCLUSIONS

Socioeconomic factors, hypoxaemia and the effects of altitudes >3500 m play a major role in the high prevalence of glucose intolerance in highlanders. Tibetan highlanders may be vulnerable to glucose intolerance, with polycythaemia as a sign of poor hypoxic adaptation, accelerated by lifestyle change and ageing.

The impact of sleep amount and sleep quality on glycemic control in type 2 diabetes: A systematic review and meta-analysis

Recent epidemiological studies have suggested that there is an association between glycemic control and sleep disturbances in patients with type 2 diabetes, but the extent is unclear. A systematic literature search was performed in nine electronic databases from inception until August 2015 without any language restriction. The search identified 20 studies (eight studies reporting duration of sleep and 15 studies evaluating sleep quality), and 15 were included in the meta-analysis. Short and long sleep durations were associated with an increased hemoglobin A_1c (HbA1c) (weighted mean difference (WMD): 0.23% [0.10-0.36], short sleep; WMD: 0.13% [0.02-0.25], long sleep) compared to normal sleep, suggesting a U-shaped dose-response relationship. Similarly, poor sleep quality was associated with an increased HbA1c (WMD: 0.35% [0.12-0.58]). Results of this study suggest that amount of sleep as well as quality of sleep is important in the metabolic function of type 2 diabetes patients. Further studies are needed to identify for the potential causal role between sleep and altered glucose metabolism.

Hypoxic Ventilatory Reactivity in Experimental Diabetes

Diabetes, apart from generalized neuropathy and microangiopathy, involves tissue hypoxia, which may drive chronic proinflammatory state. However, studies on the ventilatory control in diabetes are sparse and conflicting. In this study we examined the function and morphology of diabetic carotid bodies (CBs). Diabetes was evoked in Wistar rats with streptozotocin (70 mg/kg, i.p.). The acute hypoxic ventilatory responses (HVR) to 12 and 8 % O(2) were investigated in conscious untreated rats after 2 and 4 weeks in a plethysmographic chamber. CBs were dissected and subjected to morphologic investigations: (1) electron transmission microscopy for ultrastructure and (2) laser scanning confocal microscopy to visualize the microvascular bed in sections labeled with the lectin Griffonia simplicifolia-I (GSI), an endothelial cell marker, and fluorescein isothiocyanate (FITC). All findings were referenced to the normal healthy rats. We found that diabetes distinctly dampened the HVR. At the ultrastructural level, the diabetic CB displayed proliferation of connective tissue and neovascularization deranging the interglomal structure, and lengthening the O(2) diffusion path from capillaries to chemoreceptor cells. The chemoreceptor cells remained largely unchanged. The endothelial cell labeling confirmed the intensive angiopathy and the induction of microvessel growth. We conclude that diabetes hampers the chemical regulation of ventilation due to remodeling of CB parenchyma, which may facilitate chronic hypoxia and inflammation in the organ.

Obstructive sleep apnea and diabetes mellitus

BACKGROUND

There is convincing evidence that obstructive sleep apnea (OSA) is highly associated with impaired glucose metabolism.

OBJECTIVES

Analyze the prevalence of OSA in type 1 and type 2 diabetes mellitus (DM) patients. Evaluate the influence of OSA on glycemic control.

METHODS

The adult patients with diabetes mellitus (DM) followed in the department of internal medicine were referred to our Sleep Unit. A home respiratory polygraphy was then performed on all patients with body mass index (BMI) <40 kg/m(2). The glycemic control was assessed by the value of glycated hemoglobin (Hba1c) in the previous 3 months.

RESULTS

A total of 46 patients were studied (20 men and 26 women), the mean age was 50±15 years and mean BMI was 28.6±4.9 kg/m(2). The mean Hba1c was 8.3±1.2. Twenty three patients had type 2 DM and 23 patients had type 1 DM. Twenty nine patients (63.0%) had OSA and 8.7% had severe OSA (AHI>30/h). The mean CT90 was 5.3±12.5 and the mean AHI was 13.6±18.3. The mean AHI was similar between type 1 and type 2 DM (15.7±24.5 Vs 11.6±8.9; p=0.46). The AHI was not correlated with the BMI. Type 2 DM patients with poor glycemic control (HbA1c>7.5%) had a significantly higher mean AHI (14.3±9.0 vs 6.4±6.2; p=0.038). This difference did not remain significant after adjustment for BMI (p=0.151).

CONCLUSIONS

The prevalence of OSA in type 1 DM is similar to that found in type 2 DM. We note the high prevalence of OSA in younger patients with type 1 DM.

Therapeutic potential of intermittent hypoxia: a matter of dose

Intermittent hypoxia (IH) has been the subject of considerable research in recent years, and triggers a bewildering array of both detrimental and beneficial effects in multiple physiological systems. Here, we review the extensive literature concerning IH and its impact on the respiratory, cardiovascular, immune, metabolic, bone, and nervous systems. One major goal is to define relevant IH characteristics leading to safe, protective, and/or therapeutic effects vs. pathogenesis. To understand the impact of IH, it is essential to define critical characteristics of the IH protocol under investigation, including potentially the severity of hypoxia within episodes, the duration of hypoxic episodes, the number of hypoxic episodes per day, the pattern of presentation across time (e.g., within vs. consecutive vs. alternating days), and the cumulative time of exposure. Not surprisingly, severe/chronic IH protocols tend to be pathogenic, whereas any beneficial effects are more likely to arise from modest/acute IH exposures. Features of the IH protocol most highly associated with beneficial vs. pathogenic outcomes include the level of hypoxemia within episodes and the number of episodes per day. Modest hypoxia (9-16% inspired O2) and low cycle numbers (3-15 episodes per day) most often lead to beneficial effects without pathology, whereas severe hypoxia (2-8% inspired O2) and more episodes per day (48-2,400 episodes/day) elicit progressively greater pathology. Accumulating evidence suggests that "low dose" IH (modest hypoxia, few episodes) may be a simple, safe, and effective treatment with considerable therapeutic potential for multiple clinical disorders.

Real-time prediction of disordered breathing events in people with obstructive sleep apnea

PURPOSE

Conventional therapies for obstructive sleep apnea (OSA) are effective but suffer from poor patient adherence and may not fully alleviate major OSA-associated cardiovascular risk factors or improve certain aspects of quality of life. Predicting the onset of disordered breathing events in OSA patients may lead to improved strategies for treating OSA and inform our understanding of underlying disease mechanisms. In this work, we describe a deployable system capable of performing real-time predictions of sleep disordered breathing events in patients diagnosed with OSA, providing a novel approach for gaining insight into OSA pathophysiology, discovering population subgroups, and improving therapies.

METHODS

LArge Memory STorage and Retrieval artificial neural networks with 864 different configurations were applied to polysomnogram records from 64 patients. Wavelet transforms, measures of entropy, and other statistics were applied to six physiological signals to provide network inputs. Approximate statistical tests were used to determine the best performing network for each patient. The most important predictors of disordered breathing events in OSA patients were determined by analyzing internal network parameters.

RESULTS

The average optimized individual prediction sensitivity and specificity were 0.81 and 0.77, respectively. Predictions were better than random guessing for all OSA patients. Analysis of internal network parameters revealed a high degree of heterogeneity among disordered breathing event predictors and may reveal patient subgroups.

CONCLUSIONS

We report the first practical system to predict individual disordered breathing events in a heterogeneous group of patients diagnosed with OSA. The pattern of disordered breathing predictors suggests variable underlying pathophysiological mechanisms and highlights the need for an individualized approach to OSA diagnosis, therapy, and management.

Prevalence and Correlates of Insomnia and Excessive Sleepiness in Adults with Obstructive Sleep Apnea Symptoms

This study investigated the prevalence and correlates of insomnia and excessive sleepiness in adults presenting symptoms of obstructive sleep apnea (OSA) in the general population. Randomly selected participants ( N = 1,502; 50.7% men, 49.3% women), ages 40 to 70 yr. ( M = 53.6, SD = 8.5) were interviewed over the telephone. Insomnia and excessive sleepiness (hypersomnia) were assessed with the Bergen Insomnia Scale and the Epworth Sleepiness Scale, respectively. OSA symptoms were identified by self- or spouse reports on snoring, breathing cessations during sleep, and being tired or sleepy. The prevalence of OSA was 6.2%. Among these participants with OSA, 57.6% reported insomnia and 30.1% reported excessive sleepiness. Furthermore, OSA symptoms were associated with self-reported obesity, hypertension, diabetes, and depression, but only in participants with comorbid insomnia or excessive sleepiness.

Impact of Obstructive Sleep Apnoea on Type 2 Diabetes and Vice Versa

Type 2 diabetes and obstructive sleep apnoea (OSA) are diseases with high prevalence and major public health impact. There is evidence that OSA is independently associated with alterations in glucose metabolism. Furthermore, OSA is a significant risk factor for the development of type 2 diabetes. Possible causes might be intermittent hypoxaemia and sleep fragmentation with increased oxidative stress and sympathetic activity, which are typical features of OSA. OSA might also be a reason for ineffective treatment of type 2 diabetes. There is further evidence that the treatment of OSA by continuous positive airway pressure (CPAP) therapy might improve glucose metabolism. On the other hand, there are also hints in the literature that type 2 diabetes might induce sleep apnoea, especially in patients with autonomic neuropathy, but that OSA also facilitates the development of neuropathy in terms of mutual interactions between OSA, type 2 diabetes and diabetic neuropathy. Based on the current scientific data, clinicians have to be aware of the relations between OSA and type 2 diabetes, both from the sleep medical and the diabetological point of view.

Obstructive sleep apnea screening and postoperative mortality in a large surgical cohort

OBJECTIVE

A recent investigation at Barnes-Jewish Hospital located in St. Louis, Missouri, found that an estimated 22% of adults presenting for inpatient surgery screened as high risk for obstructive sleep apnea (OSA). Surgical patients with OSA have multiple comorbidities and are at increased risk for perioperative complications. Our objective was to determine if a prior diagnosis of OSA or a positive screen for OSA was associated with increased risk for 30-day and one-year mortality.

METHODS

B-J APNEAS (Barnes-Jewish Apnea Prevalence in Every Admission Study) was a prospective cohort study. Unselected adult surgical patients at Barnes Jewish Hospital were prospectively enrolled between February 2006 and April 2010. All patients completed preoperative OSA screening and those who were at risk for OSA according to a combination of the Berlin and Flemons screening tools received targeted postoperative interventions. STOP (loud Snoring, daytime Tiredness, Observed apneas, and high blood Pressure) and STOP-BANG (STOP, plus body mass index [BMI], age, neck circumference, and gender) scores also were obtained.

RESULTS

Overall, the sample included 14,962 patients, of whom 1939 (12.9%) reported a history of OSA. All four screening tools identified a high prevalence of undiagnosed patients at risk for OSA (9.5%-41.6%), but agreement among screens was not strong with κ statistic ranging from 0.225 to 0.611. There was no significant difference in 30-day postoperative mortality between patients with possible OSA (based on their history or on a positive OSA screen with any of the four instruments) and the rest of the surgical population. Significant differences in one-year mortality were noted between the low-risk and high-risk groups as identified by the Flemons' (4.96% vs 6.91%; p<0.0001), STOP (5.28% vs 7.57%; p<0.0001) and STOP-BANG (4.13% vs 7.45%; p<0.0001) screens. After adjusting for risk factors, none of the OSA screening tools independently predicted mortality rate up to one year postoperatively.

CONCLUSION

Neither a prior diagnosis of OSA nor a positive screen for OSA risk was associated with increased 30-day or one-year postoperative mortality. Differences in 1 year postoperative mortality were noted with three of the screening tools. The results of our study highlight uncertainties and research priorities for the medical community.

Sleep and stroke

Obstructive Sleep-Disordered Breathing (OSDB) is an under-recognized risk factor for stroke. OSDB is associated with traditional vascular risk factors such as hypertension, obesity, and diabetes, and can influence the risk for stroke through direct and indirect mechanisms. Untreated OSDB may also influence rehabilitation efforts and functional outcome following a stroke, as well as the risk for stroke recurrence. Stroke risk is greatly reduced if the OSDB is adequately treated. Conversely, OSDB may be exacerbated or caused by stroke. Increasing awareness and improving screening for OSDB is paramount in the primary and secondary prevention of stroke, and in improving stroke outcomes. The following review article is intended to highlight the current basics of epidemiology, clinical characteristics, pathophysiology, diagnosis, and treatment of OSDB in relation to stroke.

Position paper on the management of patients with obstructive sleep apnea and hypertension: joint recommendations by the European Society of Hypertension, by the European Respiratory Society and by the members of European COST (COoperation in Scientific and Technological research) ACTION B26 on obstructive sleep apnea

This article is aimed at addressing the current state of the art in epidemiology, pathophysiology, diagnostic procedures and treatment options for appropriate management of obstructive sleep apnea (OSA) in cardiovascular (particularly hypertensive) patients, as well as for the management of cardiovascular diseases (particularly arterial hypertension) in OSA patients. The present document is the result of the work done by a panel of experts participating in the European Union COST (COoperation in Scientific and Technological research) ACTION B26 on OSA, with the endorsement of the European Respiratory Society (ERS) and the European Society of Hypertension (ESH). These recommendations are particularly aimed at reminding cardiovascular experts to consider the occurrence of sleep-related breathing disorders in patients with high blood pressure. They are at the same time aimed at reminding respiration experts to consider the occurrence of hypertension in patients with respiratory problems at night.

Prevalence of self-reported sleep problems among people with diabetes in the United States, 2005-2008

INTRODUCTION

Sleep problems, including insomnia, apnea, and restless legs syndrome, are common, burdensome, and under-recognized in the United States. We sought to examine the association of sleep problems with diabetes among community-dwelling US adults.

METHODS

We examined self-reported sleep problems in 9,848 adults (aged ≥20 y) participating in the National Health and Nutrition Examination Survey 2005 through 2008. Sleep problem information was elicited via validated questionnaire. Diabetes was defined by self-reported diagnosis or glycohemoglobin of 6.5% or higher. Multivariable logistic regression with US population-based weighting was used to obtain adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for various sleep problems by diabetes status.

RESULTS

Sleep problems were common (>90% for any problem; 10%-40% for individual problems) overall, and people with diabetes were more likely than those without diabetes to report multiple problems (mean, 3.1 vs 2.5, respectively, P < .001). After adjustment for potential confounders (including demographics, body mass index, cardiovascular and kidney disease, and alcohol use), restless legs symptoms (OR, 1.40; 95% CI, 1.12-1.78), sleep apnea (OR, 1.45; 95% CI, 1.06-1.98), and nocturia (OR, 1.51; 95% CI, 1.22-1.87) were all positively associated with diabetes status.

CONCLUSION

Diabetes is associated with a higher risk of sleep problems, including not only sleep apnea but also inadequate sleep, excessive sleepiness, leg symptoms, and nocturia, independent of body mass index. Clinicians should be aware of the high prevalence of sleep problems among their patients with diabetes and should consider screening and treatment, which may improve patients' quality of life.

Sleep disorders and stroke

The purpose of this review is to highlight existing literature on the epidemiology, pathophysiology, and treatments of stroke sleep disorders. Stroke sleep disorders are associated with many intermediary vascular risk factors leading to stroke, but they may also influence these risk factors through direct or indirect mechanisms. Sleep disturbances may be further exacerbated by stroke or caused by stroke. Unrecognized and untreated sleep disorders may influence rehabilitation efforts and poor functional outcomes following stroke and increase risk for stroke recurrence. Increasing awareness and improving screening for sleep disorders is paramount in the primary and secondary prevention of stroke and in improving stroke outcomes. Many vital questions about the relationship of sleep disorders and stroke are still unanswered and await future well-designed studies.

Impact of sleep apnea on economics

Obstructive sleep apnea syndrome (OSA) alters sleep quality and is associated with sleepiness and decreased cognitive functioning. It has therefore always been recognized as a major public health issue with potential societal consequences: accidents, increased morbidity, and cognitive deficits impairing work efficiency. The number of patients diagnosed and treated for OSA has increased drastically in the last few years. In response to this epidemic, health authorities have encouraged studies investigating how patients cope with OSA and also its diagnosis, comparing ambulatory to hospital-based polysomnography. Based on epidemiological knowledge, this review aims to carefully describe the possible links between sleep apnea and public health concerns along with identifying the certitudes and missing data concerning the consequences of sleep apnea on accidents, work, economics and health-related quality of life.

Usefulness of combining intermittent hypoxia and physical exercise in the treatment of obesity

Obesity is an important public health problem worldwide and is a major risk factor for a number of chronic diseases such as type II diabetes, adverse cardiovascular events and metabolic syndrome-related features. Different treatments have been applied to tackle body fat accumulation and its associated clinical manifestations. Often, relevant weight loss is achieved during the first 6 months under different dietary treatments. From this point, a plateau is reached, and a gradual recovery of the lost weight may occur. Therefore, new research approaches are being investigated to assure weight maintenance. Pioneering investigations have reported that oxygen variations in organic systems may produce changes in body composition. Possible applications of intermittent hypoxia to promote health and in various pathophysiological states have been reported. The hypoxic stimulus in addition to diet and exercise can be an interesting approach to lose weight, by inducing higher basal noradrenalin levels and other metabolic changes whose mechanisms are still unclear. Indeed, hypoxic situations increase the diameter of arterioles, produce peripheral vasodilatation and decrease arterial blood pressure. Furthermore, hypoxic training increases the activity of glycolytic enzymes, enhancing the number of mitochondria and glucose transporter GLUT-4 levels as well as improving insulin sensitivity. Moreover, hypoxia increases blood serotonin and decreases leptin levels while appetite is suppressed. These observations allow consideration of the hypothesis that intermittent hypoxia induces fat loss and may ameliorate cardiovascular health, which might be of interest for the treatment of obesity. This new strategy may be useful and practical for clinical applications in obese patients.

Type 2 diabetes and pre-diabetes are associated with obstructive sleep apnea in extremely obese subjects: a cross-sectional study

Background

Obstructive sleep apnea (OSA) is a common yet underdiagnosed condition. The aim of our study is to test whether prediabetes and type 2 diabetes are associated with obstructive sleep apnea (OSA) in extremely obese (BMI ≥ 40 kg/m²) subjects.

Methods

One hundred and thirty seven consecutive extremely obese patients (99 females) from a controlled clinical trial [MOBIL-study (Morbid Obesity treatment, Bariatric surgery versus Intensive Lifestyle intervention Study) (ClinicalTrials.gov number NCT00273104)] underwent somnography with Embletta^® and a 2-hour oral glucose tolerance test (OGTT). OSA was defined by an apnea-hypopnea index (AHI) ≥ 5 events/hour. Patients were categorized into three groups according to criteria from the American Diabetes Association: normal glucose tolerance, pre-diabetes and type 2 diabetes. Multiple logistic regression analysis was used to identify possible determinants of OSA.

Results

The patients had a mean (SD) age of 43 (11) years and a body mass index (BMI) of 46.9 (5.7) kg/m². Males had significantly higher AHI than females, 29 (25) vs 12 (17) events/hour, p < 0.001. OSA was observed in 81% of men and in 55% of women, p = 0.008. Twenty-nine percent of subjects had normal glucose tolerance, 42% had pre-diabetes and 29% had type 2 diabetes. Among the patients with normal glucose tolerance 33% had OSA, while 67% of the pre-diabetic patients and 78% of the type 2 diabetic patients had OSA, p < 0.001. After adjusting for age, gender, BMI, high sensitive CRP and HOMA-IR, both pre-diabetes and type 2 diabetes were still associated with OSA, odds ratios 3.18 (95% CI 1.00, 10.07), p = 0.049 and 4.17 (1.09, 15.88), p = 0.036, respectively. Mean serum leptin was significantly lower in the OSA than in the non-OSA group, while other measures of inflammation did not differ significantly between groups.

Conclusions

Type 2 diabetes and pre-diabetes are associated with OSA in extremely obese subjects.

Trial registration

MOBIL-study (Morbid Obesity treatment, Bariatric surgery versus Intensive Lifestyle intervention Study) (ClinicalTrials.gov number NCT00273104)