Sleep-disordered breathing, glucose intolerance, and insulin resistance

Atomoxetine and spironolactone combine to reduce obstructive sleep apnea severity and blood pressure in hypertensive patients

BACKGROUND

Norepinephrine reuptake inhibitors such as atomoxetine (ato) can improve OSA by increasing pharyngeal muscle activity. Mineralocorticoid antagonists such as spironolactone, may potentiate the reduction of OSA severity and reduce blood pressure. We evaluated whether adding spironolactone to atomoxetine (ato-spiro) improved responses in hypertensive OSA patients.

METHODS

Twenty-one patients with an apnea-hypopnea index (AHI) between 10 and 50 events/h and a history of hypertension were recruited and crossed-over in random order to ato 80 mg and ato-spiro 80/50 mg for 1 week after a 3-day low dose run-in period. Two dropped out due to drug related side effects. Polysomnography and 24-hour blood pressure (BP) monitoring were performed at baseline and after each treatment period.

RESULTS

AHI decreased on both ato and ato-spiro from a baseline median(IQR) of 20.3(18.8 to 28.5) to 8.2(7 to 13.1) and 6.2(5.7 to 14.1), respectively (p < 0.001 for both). Systolic BP (mmHg) fell by mean(95%CI) -4.5(-13.8 to 4.8, p = 0.33) on ato and - 10.3(-19.2 to -1.5, p = 0.02) on ato-spiro, and diastolic BP dropped by -3.0(-8.0 to 2.0, p = 0.23) on ato and - 5.0(-9.1 to -0.9; p = 0.02) on ato-spiro. Both ato and ato-spiro led to a significant shift from apnea to hypopnea predominance (p < 0.001), and significant reductions in hypoxic burden (p ≤ 0.001) and REM sleep (p ≤ 0.001).

CONCLUSIONS

Both ato-spiro and ato alone decreased OSA severity similarly, but ato-spiro led to even greater, statistically significant and clinically meaningful falls in systolic and diastolic BP. BP reductions were likely due to ato-related improvements in upper airway patency and hypoxemia, and to spiro-related reduced fluid retention. These findings show promise for ato-spiro as an oral treatment for hypertensive OSA patients. REGISTERED AT CLINICALTRIALS.GOV: NCT04905979.

Targeted Hypoglossal Nerve Stimulation for Patients With Obstructive Sleep Apnea: A Randomized Clinical Trial

Importance

Evidence is lacking from randomized clinical trials of hypoglossal nerve stimulation in obstructive sleep apnea (OSA).

Objective

To evaluate the safety and effectiveness of targeted hypoglossal nerve stimulation (THN) of the proximal hypoglossal nerve in patients with OSA.

Design, Setting, and Participants

This randomized clinical trial (THN3) was conducted at 20 centers and included 138 patients with moderate to severe OSA with an apnea-hypopnea index (AHI) of 20 to 65 events per hour and body mass index (calculated as weight in kilograms divided by height in meters squared) of 35 or less. The trial was conducted from May 2015 through June 2018. Data were analyzed from January 2022 through January 2023.

Intervention

Implant with THN system; randomized 2:1 to activation at month 1 (treatment) or month 4 (control). All received 11 months of THN with follow-up at months 12 and 15, respectively.

Main Outcomes and Measures

Primary effectiveness end points comprised AHI and oxygen desaturation index (ODI) responder rates (RRs). Treatment responses at months 4 and 12/15 were defined as a 50% or greater reduction in AHI to 20 or less per hour and an ODI decrease of 25% or greater. Coprimary end points comprised (1) month 4 AHI and ODI RR in the treatment greater than the control group and (2) month 12/15 AHI and ODI RR in the entire cohort exceeding 50%. Secondary end points included sleep apnea severity (AHI and ODI) and patient-reported outcomes (Epworth Sleepiness Scale, Functional Outcomes of Sleep Questionnaire, and EQ-5D visual analog scale).

Results

Among 138 participants, the mean (SD) age was 56 (9) years, and 19 (13.8%) were women. Month 4 THN RRs were substantially greater in those in the treatment vs control group (AHI, 52.3% vs 19.6%; ODI, 62.5% vs 41.3%, respectively) with treatment-control standardized mean differences of 0.725 (95% CI, 0.360-1.163) and 0.434 (95% CI, 0.070-0.843) for AHI and ODI RRs, respectively. Months 12/15 RRs were 42.5% and 60.4% for AHI and ODI, respectively. Improvements in AHI, ODI, Epworth Sleepiness Scale, Functional Outcomes of Sleep Questionnaire, and EQ-5D visual analog scale scores were all clinically meaningful (medium to large effect size). Two serious adverse events and 100 nonserious related adverse events were observed from the implant procedure or study protocol.

Conclusions and Relevance

This randomized clinical trial found that THN demonstrated improvements in sleep apnea, sleepiness, and quality of life in patients with OSAs over an extended AHI and body mass index range without prior knowledge of pharyngeal collapse pattern. Clinically meaningful improvements in AHI and patient-reported responses compared favorably with those of distal hypoglossal nerve stimulation trials, although clinically meaningful differences were not definitive for ODI.

Trial Registration

ClinicalTrials.gov Identifier: NCT02263859.

Sleep Apnea, Obesity, and Diabetes - an Intertwined Trio

PURPOSE OF REVIEW

To synthesize the existing literature regarding the complex interplay between sleep disturbance, obesity, and diabetes. The review emphasizes the three pillars of health being diet, exercise, and sleep, with the notion that if one is ignored, then the other two could suffer.

RECENT FINDINGS

Sleep deprivation is associated with incident obesity, perhaps mediated by dysregulation in leptin and ghrelin - hormones important in regulation of appetite. Sleep apnea is very common particularly among obese people with type 2 diabetes mellitus. Treatment of sleep apnea has clear symptomatic benefits although its impact on long-term cardiometabolic health is less clear. Sleep disturbance may be an important modifiable risk for patients at risk of cardiometabolic disease. An assessment of sleep health may be an important component of the comprehensive care of patients with obesity and diabetes mellitus.

Prevalence of risk and factors associated with obstructive sleep apnea-hypopnea syndrome in an adult population in Kinshasa, Democratic Republic of Congo

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is an underdiagnosed and lesser known disease in sub-Saharan Africa. We believe that this is the first descriptive and analytical cross-sectional study in Kinshasa (from February 1 to October 31, 2021), which included respondents aged ≥18 years. The study aimed to determine the prevalence of the risk and factors associated with OSAHS. Each participant signed a free and informed consent. Statistical analyses were performed using XLStat 2020 and the Statistical Package for the Social Sciences version 24 for Windows. Odds ratios (ORs) were calculated to determine the degree of association between these variables and a high risk of OSAHS. The significance threshold was p < 0.05 and confidence interval (CI) at 95%. There were 4,162 participants, including 2,287 men (54.9%), with an mean (SD) age of 32 ± 12.6 years. The prevalence of OSAS risk was 17.4% and 7.9% for men and women, respectively. The associated risk factors were male sex (OR 4, 95% CI 3.20-5.54), hypertension (OR 6.7, 95% CI 4.87-9.30), age ≥60 years (OR 8.7, 95% CI 4.07-18.88), obesity/overweight (OR 1.94, 95% CI 1.13-3.78), and excessive daytime sleepiness (OR 2.63, 95% CI 2.05-3.56). The risk of OSAS in Kinshasa is high and it increases with age, male sex, obesity, and hypertension. The Snoring, Tiredness, Observed apnea, high blood Pressure, Body mass index, Age, Neck circumference, and male Gender (STOP-BANG) questionnaire is an easy-to-use tool for diagnostic orientation.

Association between various breathing indexes during sleep and the Epworth Sleepiness Scale score in adults

Some breathing indexes during sleep, including the apnea-hypopnea index, oxygen desaturation index, and oxygen saturation during sleep, can be recorded by overnight polysomnography. We aimed to investigate the association of various breathing indexes during sleep with the Epworth Sleepiness Scale (ESS) score in adults. We retrospectively collected the clinical and overnight polysomnography data of 2829 adults aged 20 years or older from November 2011 to June 2017. The association of various breathing indexes during sleep and ESS score was analyzed using univariate and multivariate logistic regression analysis for all adults (20-91 years), and in each sex and of body mass index (<26 kg/m2 vs ≥26 kg/m2). The mean ESS score was 6.2 (standard deviation = 4.3; range = 0-24) for all adults. After adjustment for age, sex, many common diseases, and health-related habits, apnea-hypopnea index, oxygen desaturation index, percentage of oxygen saturation below 90% during sleep, and percentage of oxygen saturation below 85% during sleep were significantly positively associated with ESS score in all adults, whereas mean oxygen saturation during sleep, minimal oxygen saturation during sleep, and awake oxygen saturation during sleep were significantly negatively associated with ESS score in all adults. In subgroup analysis, we found that the association between breathing indexes during sleep and ESS score was similar in both sex, but was significant in subjects of body mass index ≥ 26 kg/m2. All breathing indexes during sleep had significant positive or negative correlation with ESS score in all adults, especially in obese subjects.

Sleep disordered breathing and the risk of severe maternal morbidity in women with preeclampsia: A population-based study

OBJECTIVE

Obstructive sleep apnea (OSA) may exacerbate the widespread endothelial dysfunction seen in preeclampsia, potentially worsening clinical outcomes. We aimed to assess whether OSA is associated with an increased risk of severe maternal morbidity, cardiovascular morbidity, and healthcare utilization among women with preeclampsia.

STUDY DESIGN

We performed a retrospective cohort study utilizing data from the National Perinatal Information Center (2010-2014) in the United States.The cohort comprised women with preeclampsia. We estimated the association between OSA and the outcomes using logistic regression analyses and determined odds ratio adjusted for demographic factors and comorbidities (ORadj) and associated 95% confidence intervals (CI).

MAIN OUTCOME MEASURES

The primary outcome was a composite of mortality and severe maternal morbidity comprising intensive care unit (ICU) admission, acute renal failure, pulmonary edema, pulmonary embolism, congestive heart failure, cardiomyopathy, and stroke. Secondary outcomes comprised the subset of cardiovascular events, as well as increased healthcare utilization (including Cesarean delivery, preterm birth, ICU admission, and prolonged length of hospital stay).

RESULTS

In total, 71,159 women had preeclampsia, including 270 (0.4 %) with OSA. Women with preeclampsia and OSA were more likely to experience severe maternal morbidity than women without OSA (ORadj 2.65, 95 % CI [1.94-3.61]). Moreover, women with concomitant OSA had more severe cardiovascular morbidity than women without OSA (ORadj 5.05, 95 % CI [2.28-11.17]). Accordingly, OSA was associated with increased healthcare utilization in women with preeclampsia (ORadj. 2.26, 95 % CI [1.45-3.52]).

CONCLUSION

In women with preeclampsia, OSA increases the risk for severe maternal morbidity, cardiovascular morbidity, and healthcare utilization.

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.

Ocular Complications of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA), the most common form of sleep-disordered breathing, is characterized by repetitive episodes of paused breathing during sleep, which in turn induces transient nocturnal hypoxia and hypercapnia. The high prevalence of OSA and its associated health consequences place a heavy burden on the healthcare system. In particular, the consequent episodic oxygenic desaturation/reoxygenation series and arousals from sleep in patients with OSA have the potential to trigger oxidative stress, elevated systemic inflammatory responses, and autonomic dysfunction with sympathetic activation. Given these adverse side-effects, OSA is highly correlated to many eye diseases that are common in everyday ophthalmic practices. Some of these ocular consequences are reversible, but they may permanently threaten a patient’s vision if not treated appropriately. Here, this article seeks to review the ocular consequences and potential pathophysiologic associations in patients with OSA. Understanding these OSA-related eye diseases may help clinicians provide comprehensive care to their patients.

The relationship between metabolic syndrome and obstructive sleep apnea syndrome: a nationwide population-based study

There has been a need for research on the association between metabolic syndrome (MetS) and obstructive sleep apnea syndrome (OSAS) using large data such as nationwide population-based data that adjusts important confounding factors. Therefore, we investigated the relationship between MetS and OSAS. The data source we used was the National Health Insurance Service claims database managed by the Republic of Korea government, in which 10,113,560 individuals were enrolled in 2009 and followed up until 2018. The independent association of MetS with the risk of OSAS was determined using a Cox proportional hazards model with adjustment for age, sex, smoking status, alcohol consumption, regular physical exercise, and body mass index. Our results showed that MetS were strongly associated to OSAS which was adjusted for several confounding factors. Also, we found men, increased waist circumference and increased triglyceride are important risk factors for OSAS.

Effect of 12-week continuous positive airway pressure therapy on glucose levels assessed by continuous glucose monitoring in people with type 2 diabetes and obstructive sleep apnoea; a randomized controlled trial

Aim

Obstructive sleep apnoea (OSA) is frequent in type 2 diabetes (T2D). The aim was to investigate the effect of a 12-week treatment with continuous positive airway pressure (CPAP) on glycaemic control assessed by continuous glucose monitoring (CGM), HbA1c and fasting blood glucose in patients with T2D and newly detected OSA.

Methods

In a randomized controlled multicentre study, 72 participants with T2D and moderate to severe OSA (78% male, age 62 ± 7, AHI 35 ± 15) were recruited from outpatient clinics in three Danish hospitals and were randomized to CPAP intervention or control. The main outcome was glycaemic control assessed by 6 days CGM at baseline and after 12-week therapy, as well as by HbA1c and fasting blood glucose.

Results

No significant changes were found in average glucose levels, time in glucose range, time with hypoglycaemia, time with hyperglycaemia or coefficient of variability. HbA1c decreased 0.7 mmol/mol (0.07%; P = .8) in the CPAP group and increased 0.8 mmol/mol (0.08%; P = .6) in the control group (intergroup difference, P = .6). Fasting blood glucose increased by 0.2 mmol/L (P = .02) in the CPAP group and by 0.4 mmol/L (P = .01) in the control group (intergroup difference, P = .7). In a prespecified subgroup analysis comparing participants with high adherence (minimum usage of four hours/night for 70% of all nights) to CPAP to the control group, no significant changes were observed either, although these participants had a tendency towards better glycaemic indices.

Conclusions

CPAP treatment for 12 weeks does not significantly change glycaemic control in patients with type 2 diabetes and OSA.

Rationale and design of the Hyperglycemic Profiles in Obstructive Sleep Apnea (HYPNOS) trial

The Hyperglycemic Profiles in Obstructive Sleep Apnea (HYPNOS) randomized clinical trial was conducted in adults with type 2 diabetes and moderate-to-severe obstructive sleep apnea (OSA) to determine whether treatment with positive airway pressure (PAP) therapy is associated with improvements in glycemic measures. Participants were randomly assigned to PAP therapy with lifestyle counseling or lifestyle counseling alone. While observational and experimental evidence indicate that intermittent hypoxemia and recurrent arousals in OSA may alter glucose metabolism and worsen glycemic measures, the effect of treating OSA with PAP therapy on these measures in type 2 diabetes is uncertain. Adequately powered randomized clinical trials have yet to be performed to demonstrate whether PAP therapy for OSA in patients with type 2 diabetes can improve glycemic measures. The HYPNOS trial was designed to determine whether PAP therapy for OSA in patients with type 2 diabetes over 3 months leads to improvements in glycemic measures including glycemic variability (standard deviation) based on Dexcom G4 Platinum continuous glucose monitoring. Secondary objectives were to assess the effects of PAP therapy for OSA on measures of: (1) glycemic variability based on Abbott Freestyle Pro Libre continuous glucose monitoring; (2) point-of-care hemoglobin A1c (HbA1c); (3) degree of post-prandial hyperglycemia as determined by 7-point self-monitoring of blood glucose; (4) clinic and ambulatory blood pressure; and (5) endothelial function. The HYPNOS trial was designed to address gaps in our understanding of the effects of PAP therapy on glucose metabolism in adults with type 2 diabetes and moderate-to-severe OSA. Trial Registration: ClinicalTrials.gov Identifier NCT02454153.

The Veterans Affairs Continuous Positive Airway Pressure Use and Diabetic Retinopathy Study

SIGNIFICANCE

Obstructive sleep apnea has been linked to the development and progression of diabetic retinopathy. In this study, diabetic patients compliant with continuous positive airway pressure therapy (CPAP) for sleep apnea were less likely to have retinopathy, emphasizing the benefits and potential therapeutic role of CPAP in individuals with both conditions.

PURPOSE

The aim of this study was to compare the prevalence of diabetic retinopathy in type 2 diabetic patients with obstructive sleep apnea who were compliant with CPAP therapy with those who were not compliant with CPAP therapy.

METHODS

A retrospective cross-sectional review of type 2 diabetic patients using CPAP for obstructive sleep apnea was conducted. The prevalence of retinopathy was identified, and groups with and without retinopathy were compared using univariate analyses and multivariate logistic regression.

RESULTS

The prevalence of retinopathy was 19.6% (n = 321). Retinopathy was significantly less prevalent in those compliant with CPAP (odds ratio, 0.54; 95% confidence interval, 0.31 to 0.94; P = .04). The relationship remained statistically significant when adjusting for other factors known to impact the course of diabetic eye disease.

CONCLUSIONS

Increased CPAP compliance may mitigate the risk of developing diabetic retinopathy in type 2 diabetic patients with obstructive sleep apnea.

HMGB1/TLR4 promotes apoptosis and reduces autophagy of hippocampal neurons in diabetes combined with OSA

AIMS

Obstructive sleep apnea (OSA) combined with type 2 diabetes (T2DM) may lead to cognitive dysfunction. We previously reported that cognitive impairment is exacerbated in KKAy mice exposed to intermittent hypoxia (IH), during which the DNA binding protein HMGB1 mediates hippocampal neuronal apoptosis by maintaining microglia-associated neuroinflammation, but the underlying mechanism remains largely unknown.

MATERIALS AND METHODS

We performed immunofluorescence, Western blotting, and immunohistochemistry experiments in mouse hippocampal tissues and HT22 cells. KKAy type 2 diabetes model mice and normal C57BL/6J mice were exposed to IH or intermittent normoxia. HT22 cells were cultured in high glucose medium and exposed to IH or intermittent normoxia. We transfected HMGB1 siRNA into HT22 cells and then treated them with high glucose combined with intermittent hypoxia.

KEY FINDINGS

In conclusion, IH aggravated apoptosis and autophagy defects in T2DM mice, and increased the protein expression of HMGB1 and TLR4. This was also confirmed in HG + IH-treated hippocampal HT22 cells. HMGB1 siRNA can significantly reduce the protein expression of HMGB1 and TLR4, reverse neuronal apoptosis and enhance autophagy.

SIGNIFICANCE

We believe that HMGB1 is a key factor in the regulation of hippocampal neuronal apoptosis and autophagy defects in T2DM combined with OSA. Targeting HMGB1/TLR4 signaling as a novel approach may delay or prevent the increased apoptosis and decreased autophagy induced by T2DM combined with OSA, and may ultimately improve cognitive dysfunction.

Temporal Association Between Respiratory Events and Reflux in Patients With Obstructive Sleep Apnea and Laryngopharyngeal Reflux

STUDY OBJECTIVES

The aim of the current study was to test the hypothesis that there is a temporal correlation between reflux episodes and respiratory events in patients with laryngopharyngeal reflux and obstructive sleep apnea.

METHODS

Adults with clinically diagnosed laryngopharyngeal reflux confirmed by two validated instruments (reflux symptom index ≥ 13 and reflux finding score ≥ 7) and obstructive sleep apnea (OSA) underwent full polysomnography with concomitant and synchronized multichannel intraluminal impedance-pH esophageal monitoring. The apnea-hypopnea and arousal indexes that occurred 15, 30, and 45 minutes before and after each reflux episode were recorded and compared to full-night apnea and hypopnea and arousal index.

RESULTS

We studied 27 patients (14 males, age 51.7 ± 9.1 years, body mass index 32.4 ± 4.2 kg/m²) with laryngopharyngeal reflux (reflux symptom index 16 ± 2 and reflux finding score 12 ± 3) and OSA (apnea-hypopnea index = 32.3 ± 28.4 events/h). We evaluated 102 reflux episodes. Almost half of the reflux episodes occurred while awake (43.1%) and only five reflux episodes (4.9%) occurred during an obstructive respiratory event. The apnea and hypopnea and arousal indexes 15, 30, and 45 minutes before and after reflux episodes were lower than full-night apnea and hypopnea and arousal indexes, respectively.

CONCLUSIONS

Among patients with well-established laryngopharyngeal reflux and OSA, there is no temporal association between reflux and obstructive respiratory events. Even though the data comprised a small sample size, it seems that a more complex mechanism is involved with these two highly prevalent diseases.

Upright posture increases oxyhemoglobin saturation in Peruvian highlanders

At high altitude, hypoxia amplifies oxyhemoglobin saturation (S_PO₂) swings with changes in respiratory mechanics. Our objective was to examine the effects of posture on S_PO₂ and determine predictors of postural S_PO₂ changes in highlanders. 50 native highlanders from Puno, Peru (3825 m) assumed supine and upright-seated postures, in rotating sequence, while undergoing continuous pulse-oximetry. We compared mean S_pO₂ in each posture with a paired t-test. We examined associations of BMI, age, sex and spirometry with postural S_pO₂ changes with mixed-effects linear regression. In highlanders, S_pO₂ was 84% in the supine posture and was 1.0% ± 1.1 (p < 0.0001) greater in the upright-seated posture. Greater postural changes in S_pO₂ were associated with older age (p = 0.01 for interaction) but not with sex, BMI, FVC or FEV₁. In highlanders, S_pO₂ is higher in the upright-seated compared to supine posture, especially with older age. Because we generally sleep flat, posture may contribute significantly to highlanders' hypoxemic burden during sleep. Postural intervention during sleep may mitigate nocturnal hypoxemia.

Role of melanocortin 4 receptor in hypertension induced by chronic intermittent hypoxia

AIM

We previously demonstrated that central nervous system (CNS) melanocortin 4 receptors (MC4R) play a key role in regulating blood pressure (BP) in some conditions associated with increased SNS activity, including obesity. In this study, we examined whether activation of CNS MC4R contributes to chronic intermittent hypoxia (CIH)-induced hypertension and ventilatory responses to hypercapnia.

METHODS

Rats were instrumented with an intracerebroventricular (ICV) cannula in the lateral cerebral ventricle for continuous infusion of MC4R antagonist (SHU-9119) and telemetry probes for measuring mean arterial pressure (MAP) and heart rate (HR). Untreated and SHU-9119-treated rats as well as obese and lean MC4R-deficient rats were exposed to CIH for 7-18 consecutive days.

RESULTS

Chronic intermittent hypoxia reduced cumulative food intake by 18 ± 5 g while MAP and HR increased by 10 ± 3 mm Hg and 9 ± 5 bpm in untreated rats. SHU-9119 increased food intake (from 15 ± 1 to 46 ± 3 g) and prevented CIH-induced reduction in food intake. CIH-induced hypertension was not attenuated by MC4R antagonism (average increase of 10 ± 1 vs 9 ± 1 mm Hg for untreated and SHU-9119 treated rats). In obese MC4R-deficient rats, CIH for 7 days raised BP by 11 ± 4 mm Hg. However, when MC4R-deficient rats were food restricted to prevent obesity, CIH-induced hypertension was attenuated by 32%. We also found that MC4R deficiency was associated with impaired ventilatory responses to hypercapnia independently of obesity.

CONCLUSION

These results show that obesity and the CNS melanocortin system interact in complex ways to elevate BP during CIH and that MC4R may be important in the ventilatory responses to hypercapnia.

Diabetes sleep treatment trial: Premise, design, and methodology

The Diabetes Sleep Treatment Trial (DSTT) is a multi-site, double-blinded, randomized, sham-controlled trial. The study objective is to test whether treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) treatment results in improved glycemic control and diabetes self-management behavior compared to participants on a sham-CPAP (sub-therapeutic) device in participants with type 2 diabetes mellitus (T2DM) and co-morbid OSA. The purpose of this paper is to describe the premise for the DSTT, the study design, and the methodology used in this on-going trial. The target enrollment is 210 randomly assigned participants recruited from two sites. The primary outcome for glucose control is HbA1C; additional outcomes for diabetes self-management include objectively measured steps walked and subjectively measured diabetes-related distress, diabetes empowerment, and diabetes knowledge. All participants receive individual diabetes education and counseling for 6 weeks over two individual sessions and three telephone calls. Participants are randomized to receive either sham or active CPAP for 12 weeks, after which, they "guess" their group assignment; this will assist in determining the success of blinding participants to treatment group assignment. Participants revealed to be on active CPAP will be encouraged to continue CPAP for an additional 12 weeks; participants who had been on sham devices will be encouraged to have a repeat CPAP titration study and to crossover to active CPAP treatment for 24 weeks. An intention-to-treat approach will be used for efficacy analyses. The trial is registered with Clinicaltrials.gov (NCT01901055).

Retinal vein occlusion and obstructive sleep apnea: a series of 114 patients

PURPOSE

Evaluate the prevalence of obstructive sleep apnea (OSA) in patients with retinal vein occlusion (RVO).

METHODS

A prospective and controlled study including 114 patients from January to September 2016, who were divided into two groups: 69 patients with RVO (RVO+) and 45 controls (RVO-), matched for age, sex and disease. All the patients completed a simple questionnaire and the Epworth Sleepiness Scale and underwent a RUSleeping^® (portable monitoring device and then continuously monitored the subject's respiration to detect respiratory events). In addition, all patients with RVO were administered OSA screening with a polysomnography (PSG) during an overnight stay in the hospital, which was analysed by a single sleep apnea specialist.

RESULTS

Sleep apnea was suspected in 73.9% in the RVO group and 63% in the control group based on the simple questionnaire; 22% in the RVO group and 4.3% in the control group according to the Epworth Sleepiness Scale; 82.6% in the RVO group and 55.6% in the control group (p = 0.005) according to RUSleeping^® . Multivariate logistic regression analysis (based on RUsleeping^® ) confirmed that RVO was associated with OSA (adjusted odds ratio, 5.65, [1.60-19.92], p = 0.007). All patients in the RVO group were confirmed by PSG, and finally, 91.5% were diagnosed with moderate-to-severe OSA. Among the RVO+ patients, the mean apnea-hypopnoea index (AHI) was 42.2 events per hour (7.7-96.5). OSA was moderate in 22% patients and severe in 69.5% patients. There was no significant relationship between RVO severity and the PSG data variables.

CONCLUSION

The systematic screening of OSA with the gold standard PSG found a high prevalence of OSA in patients with RVO. The OSA is probably a risk factor associated with RVO. Polysomnography remains the gold standard method; nevertheless, the RUsleeping^® RTS portable monitoring device can assess the presence and severity of sleep apnea with a low failure rate and a single use, prior to PSG, which is less available in clinical practice. Further studies with larger samples are needed to clarify the association.

Associations between polysomnography and actigraphy-based sleep indices and glycemic control among those with and without type 2 diabetes: the Multi-Ethnic Study of Atherosclerosis

Study Objectives

To examine the associations of sleep measures with hemoglobin A1c (HbA1c) among individuals with and without type 2 diabetes.

Methods

Data were from 2049 Multi-Ethnic Study of Atherosclerosis participants taking part in a sleep ancillary study. Cross-sectional linear regression models examined associations of actigraphy estimates of sleep (sleep duration, variability, and maintenance efficiency) and polysomnography measures (obstructive sleep apnea [OSA] and hypoxemia) with HbA1c, stratified by diabetes status. Primary models were adjusted for demographics, lifestyle behaviors, and obesity.

Results

Among individuals with diabetes (20 per cent population), those who slept <5 hr/night had greater HbA1c than those who slept 7-8 hr/night (7.44 vs. 6.98 per cent, ptrend = 0.04), with no attenuation of associations after adjusting for OSA/hypoxemia. In women with diabetes, but not men, those in the lowest quartile of sleep maintenance efficiency had greater HbA1c than those in the highest quartile of sleep maintenance efficiency (7.60 vs. 6.97 per cent, ptrend < 0.01). Among those without diabetes, individuals with severe OSA or in the highest quartile of hypoxemia had significantly greater HbA1c than those without OSA or who were in the lowest quartile of hypoxemia (5.76 vs. 5.66 per cent, ptrend = 0.01; 5.75 vs. 5.66 per cent, ptrend < 0.01, respectively). Associations did not meaningfully differ by race/ethnicity.

Conclusions

Among individuals with diabetes, HbA1c was significantly higher in men and women with short sleep duration and in women with poor sleep maintenance efficiency, suggesting a role for behavioral sleep interventions in the management of diabetes. Among individuals without diabetes, untreated severe OSA/hypoxemia may adversely influence HbA1c.

A Pilot Study to Determine the Effect of Three Months of Oral Appliance Therapy using a Mandibular Advancement Device on HbA1c in Subjects with Type 2 Diabetes Mellitus and Obstructive Sleep Apnea

PURPOSE

Continuous positive air pressure (CPAP) is recommended for obstructive sleep apnea (OSA) with type 2 diabetes mellitus (T2DM) but cost and compliance are major barriers. A mandibular advancement device (MAD) may be an economical, feasible alternative to CPAP. Various studies have been published to recommend MAD as an alternative to CPAP for OSA, but not regarding its efficacy for patients having OSA as well as T2DM. This study aims to objectively and subjectively evaluate oral appliance therapy using a MAD in patients having OSA as well as T2DM.

MATERIALS AND METHODS

Patients who visited the hospital clinic having OSA as well as T2DM were recruited. After giving informed consent, participants were divided into three equally sized groups of three grades of OSA (mild, moderate, severe) on the basis of a polysomnography report and were given intervention of MAD at 50% of maximum mandibular protrusion and 20% of maximum interincisal opening. Objective outcomes were HbA1c level and apnea hypopnea index score (AHI). Subjective outcomes were Epworth Sleepiness Scale (ESS) and the Berlin Questionnaire. All outcomes were assessed before and after 3 months of intervention.

RESULTS

A statistically significant difference was seen in all outcomes after intervention with MAD (p < 0.01) in all groups except HbA1c level in participants having severe OSA.

CONCLUSION

MAD may be recommended in patients having OSA as well as T2DM. This study provides evidence to inform health care workers about possible use of MAD in OSA with T2DM.

Screening Questionnaires for Obstructive Sleep Apnea: An Updated Systematic Review

Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder and is associated with significant morbidity. We sought to present an updated systematic review of the literature on the accuracy of screening questionnaires for OSA against polysomnography (PSG) as the reference test. Using the main databases (including Medline, Cochrane Database of Systematic Reviews and Scopus) we used a combination of relevant keywords to filter studies published between January 2010 and April 2017. Population-based studies evaluating the accuracy of screening questionnaires for OSA against PSG were included in the review. Thirty-nine studies comprising 18 068 subjects were included. Four screening questionnaires for OSA had been validated in selected studies including the Berlin questionnaire (BQ), STOP-Bang Questionnaire (SBQ), STOP Questionnaire (SQ), and Epworth Sleepiness Scale (ESS). The sensitivity of SBQ in detecting mild (apnea-hypopnea index (AHI) ≥ 5 events/hour) and severe (AHI ≥ 30 events/hour) OSA was higher compared to other screening questionnaires (range from 81.08% to 97.55% and 69.2% to 98.7%, respectively). However, SQ had the highest sensitivity in predicting moderate OSA (AHI ≥ 15 events/hour; range = 41.3% to 100%). SQ and SBQ are reliable tools for screening OSA among sleep clinic patients. Although further validation studies on the screening abilities of these questionnaires on general populations are required.

Impact of non-apnea sleep disorders on diabetic control and metabolic outcome - A population-based cohort study

OBJECTIVE

There has been a growing recognition that obstructive sleep apnea (OSA) could increase the propensity for type 2 diabetes the metabolic syndrome. However, studies concerning about the impact of non-apnea sleep disorders (NSD) on diabetes control and metabolic outcomes are relatively scarce. Our aim is to investigate the impact of non-apnea sleep disorders (NSD) on diabetic control and associated metabolic outcomes in patients with type 2 diabetes.

METHODS

The data were obtained from two nationwide population-based databases for a period 2007 to 2012. A total 66,992 patients with type 2 diabetes were enrolled and divided into two cohorts based on comorbidity with or without a NSD diagnosis, and were followed up four years. The primary outcomes were to compare rate of change in HbA1c and associated metabolic outcomes during follow-up visits between patients with or without NSD. The secondary outcome is to examine whether NSD were associated with poor glycemic control of the last clinical records while controlling for the baseline HbA1c value.

RESULTS

Of the 66,992 patients with type 2 diabetes, 14.82% had comorbidity with a NSD. HbA1C decreases were significantly lower by 0.04% in the NSD group (P < 0.05), and triglyceride (TG) decreases remained significantly lower by 2.53% in the NSD group (P < 0.05). Furthermore, patients in the NSD group had an 8% higher risk of poor glycemic control (HbA1C >9) (OR = 1.08; 95%CI, 1.01-1.16).

CONCLUSION

Our findings indicated patients with type 2 diabetes comorbid with NSD had a slower improvement in HbA1c compared with the comparison cohort. It may because there may exist potential floor effect given those with NSD having significantly lower HbA1c values at baseline. On the other hand, the poor diabetic control among those with NSD may be also affected by other confounders such as medical treatment or interventions. Nevertheless, given the rapidly increasing prevalence of metabolic diseases and subsequent complications, the results may highlight the importance of sleep in the clinical management of type 2 diabetes.

Review of and Updates on Hypertension in Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a prevalent sleep disorder as is hypertension (HTN) in the 21st century with the rising incidence of obesity. Numerous studies have shown a strong association of OSA with cardiovascular morbidity and mortality. There is overwhelming evidence supporting the relationship between OSA and hypertension (HTN). The pathophysiology of HTN in OSA is complex and dependent on various factors such as sympathetic tone, renin-angiotensin-aldosterone system, endothelial dysfunction, and altered baroreceptor reflexes. The treatment of OSA is multifactorial ranging from CPAP to oral appliances to lifestyle modifications to antihypertensive drugs. OSA and HTN both need prompt diagnosis and treatment to help address the growing cardiovascular morbidity and mortality due to these two entities.

Sleep-disordered breathing and disorders of glucose metabolism

AIMS

The authors identified the risk of disorders of glucose metabolism (DGM) for sleep-disordered breathing (SDB).

METHODS

We conducted a cross-sectional study in 536 men aged 33-84 years. Patients with diabetes medication were excluded for the analysis and DGM were diagnosed by fasting plasma glucose≥100mg/dl and/or 2h plasma glucose ≥140mg/dl.

RESULTS

The prevalence of DGM in subjects with and without severe SDB, which was judged by an apnea-hypopnea index (AHI) of 30, were 64.9% and 53.3%, which showed no significant difference. The adjusted odds ratios (ORs) (95% confidence intervals [CIs]) of the logarithmic-transformed AHI and that of C-reactive protein for DGM were 1.3 (0.87-2.0) and 2.3 (1.5-3.6), respectively. When the subjects were categorized by the severity of SDB, the ORs (95% CIs) of subjects with mild, moderate and severe SDB against subjects without SDB were 2.9 (1.8-4.6), 1.2 (0.72-2.1) and 1.5 (0.8-3.0), respectively.

CONCLUSION

A significant association was observed between mild SDB and the presence of DGM in male subjects of this study.

Effect of adrenal medullectomy on metabolic responses to chronic intermittent hypoxia in the frequently sampled intravenous glucose tolerance test

Obstructive sleep apnea is associated with type 2 diabetes. We have previously developed a mouse model of intermittent hypoxia (IH) mimicking oxyhemoglobin desaturations in patients with sleep apnea and have shown that IH increases fasting glucose, hepatic glucose output, and plasma catecholamines. We hypothesize that adrenal medulla modulates glucose responses to IH and that such responses can be prevented by adrenal medullectomy. We performed adrenal medullectomy or sham surgery in lean C57BL/6J mice, which were exposed to IH or intermittent air (control) for 4 wk followed by the frequently sampled intravenous glucose tolerance test (FSIVGTT) in unanesthetized unrestrained animals. IH was administered during the 12-h light phase (9 AM to 9 PM) by decreasing inspired oxygen from 21 to 6.5% 60 cycles/h. Insulin sensitivity (S_I), insulin independent glucose disposal [glucose effectiveness (S_G)], and the insulin response to glucose (AIR_G) were determined using the minimal model method. In contrast to our previous data obtained in restrained mice, IH did not affect fasting blood glucose and plasma insulin levels in sham-operated mice. IH significantly decreased S_G but did not affect S_I and AIR_G Adrenal medullectomy decreased fasting blood glucose and plasma insulin levels and increased glycogen synthesis in the liver in hypoxic mice but did not have a significant effect on the FSIVGTT metrics. We conclude that, in the absence of restraints, IH has no effect on glucose metabolism in lean mice with exception of decreased S_G, whereas adrenal medullectomy decreases fasting glucose and insulin levels in the IH environment.NEW & NOTEWORTHY To our knowledge, this is the first study examining the role of adrenal catecholamines in glucose metabolism during intermittent hypoxia (IH) in unanesthetized unrestrained C57BL/6J mice. We report that IH did not affect fasting glucose and insulin levels nor insulin sensitivity and insulin secretion during, whereas glucose effectiveness was decreased. Adrenal medullectomy decreased fasting blood glucose and insulin levels in mice exposed to IH but had no effect on glucose metabolism, insulin secretion, and insulin sensitivity.

Obstructive Sleep Apnea, Daytime Sleepiness, and Type 2 Diabetes

PURPOSE

The purpose of this article is to review the literature on obstructive sleep apnea, resultant daytime sleepiness, and type 2 diabetes mellitus, as the state of evidence exists.

METHODS

A search was conducted on Medline and CINAHL using the search terms sleep apnea syndromes, obstructive sleep apnea, disorders of excessive somnolence, type 2 diabetes mellitus, and insulin resistance. This review includes only published research studies in English, in adults aged 19 years or older. There were 109 citations when the terms were combined, 36 citations that were identified as research studies, no randomized clinical trials, and only 1 qualitative study.

RESULTS

Obstructive sleep apnea and type 2 diabetes share the risk factors of age and central abdominal obesity. Recent studies suggest that obstructive sleep apnea and type 2 diabetes not only frequently coexist but also have a bidirectional association wherein each condition exacerbates the other. The mechanism whereby obstructive sleep apnea affects glucose metabolism is likely repetitive hypoxia and sleep fragmentation, which cause a stress response with increased sympathetic nervous system activity, increased fatigue-causing cytokines, and altered leptin levels that result in weight gain. In addition, daytime sleepiness results in an impaired mood state that may impede diabetes management.

CONCLUSIONS

Type 2 diabetes is prevalent in persons with obstructive sleep apnea, although the direction of causality is unknown. More research, including randomized clinical trials, is needed to determine how obstructive sleep apnea and daytime sleepiness affect persons with type 2 diabetes.

J-curve relation between daytime nap duration and type 2 diabetes or metabolic syndrome: A dose-response meta-analysis

Adequate sleep is important for good health, but it is not always easy to achieve because of social factors. Daytime napping is widely prevalent around the world. We performed a meta-analysis to investigate the association between napping (or excessive daytime sleepiness: EDS) and the risk of type 2 diabetes or metabolic syndrome, and to quantify the potential dose-response relation using cubic spline models. Electronic databases were searched for articles published up to 2016, with 288,883 Asian and Western subjects. Pooled analysis revealed that a long nap (≥60 min/day) and EDS were each significantly associated with an increased risk of type 2 diabetes versus no nap or no EDS (odds ratio 1.46 (95% CI 1.23-1.74, p < 0.01) for a long nap and 2.00 (1.58-2.53) for EDS). In contrast, a short nap (<60 min/day) was not associated with diabetes (p = 0.75). Dose-response meta-analysis showed a J-curve relation between nap time and the risk of diabetes or metabolic syndrome, with no effect of napping up to about 40 minutes/day, followed by a sharp increase in risk at longer nap times. In summary, longer napping is associated with an increased risk of metabolic disease. Further studies are needed to confirm the benefit of a short nap.

Obstructive Sleep Apnoea, Glucose Tolerance and Liver Steatosis in Obese Women

In this study of obstructive sleep apnoea (OSA), glucose tolerance and liver steatosis in females from an obesity unit, 45 patients (mean age 46.8 years, mean body mass index 39.4 kg/m2, all non-diabetic and alcohol abstainers) underwent nocturnal polysomnography, a 2 h oral glucose tolerance test and abdominal ultrasonography. OSA, defined as an apnoea–hypopnoea index (AHI) of ≤ 10 events/h, was present in 20 patients (44%). Impaired glucose tolerance (IGT) was found in eight patients (40%) with OSA and three patients (12%) without OSA; there was a positive linear relationship between AHI and post-load glucose levels. On multivariate logistic regression analysis, IGT was predicted by OSA independently of age, waist circumference, systolic blood pressure and current smoking. Liver steatosis was present in 37 women (82.2%), of whom six had grade III steatosis. Of the variables tested, IGT was the only predictor of grade III steatosis. In conclusion, OSA is an independent predictor of IGT which, in turn, is associated with severe liver steatosis in an obesity unit-based sample of women.

Pharyngeal collapsibility during sleep is elevated in insulin-resistant females with morbid obesity

Insulin resistance is associated with sleep apnoea, leading us to hypothesise that it is also associated with elevations in pharyngeal collapsibility, even in the absence of sleep apnoea.90 bariatric patients were characterised for sleep apnoea, pharyngeal collapsibility and insulin resistance. Patients with a respiratory disturbance index (RDI) >10 events·h(-1), diabetes mellitus, tonsillar hypertrophy and pulmonary disease were excluded. The remaining 14 females underwent collapsibility measurements (passive critical pressure, Pcritp ) during non-rapid eye movement sleep. The homeostasis model assessment (HOMA) index, a measure of insulin resistance, was derived from measurements of fasting glucose and insulin levels, and compared to Pcritp Groups with high Pcritp compared to low Pcritp did not differ in age, body mass index or RDI. HOMA and insulin were elevated in the high Pcritp group compared to the low Pcritp group (p<0.02). Pcritp correlated with HOMA (Spearman's ρ=0.565, 95% CI 0.104-0.862; p=0.035) and insulin (Spearman's ρ=0.609 95% CI 0.196-0.835; p=0.021).Obese insulin-resistant subjects without frank diabetes or sleep apnoea demonstrate preclinical elevations in pharyngeal collapsibility, which may increase their susceptibility to sleep apnoea. Our findings suggest that insulin resistance could play a significant role in sleep apnoea pathogenesis by generating requisite elevations in pharyngeal collapsibility.

A community-oriented framework to increase screening and treatment of obstructive sleep apnea among blacks

OBJECTIVE

Obstructive sleep apnea (OSA) is a leading sleep disorder that is disproportionately more prevalent in minority populations and is a major risk factor for cardiovascular disease (CVD) morbidity and mortality. OSA is associated with many chronic conditions including hypertension, diabetes, and obesity, all of which are disproportionately more prevalent among blacks (ie, peoples of African American, Caribbean, or African descent).

METHODS

This article reviews studies conducted in the United States (US) that investigated sleep screenings and adherence to treatment for OSA among blacks. In addition, guidelines are provided for implementing a practical framework to increase OSA screening and management among blacks.

RESULTS

Several studies have documented racial/ethnic disparities in adherence to treatment for OSA. However, despite its public health significance, there is a paucity of studies addressing these disparities. Further, there is a lack of health programs and policies to increase screening and treatment of OSA among blacks and other minority populations. A practical framework to increase the number of blacks who are screened for OSA and treated appropriately is warranted. Such a framework is timely and major importance, as early identification of OSA in this high-risk population could potentially lead to early treatment and prevention of CVD, thereby reducing racial and ethnic disparities in sleep-related CVD morbidity and mortality.

[Prevalence of metabolic syndrome in a population of apneic patients: a prospective study with cardiovascular risk estimation]

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is a highly prevalent clinical condition and frequently associated with obesity. Recent literature has suggested the independent contribution of OSAS in the pathogenesis of metabolic disturbances. Metabolic syndrome (MS), a cardiovascular risk factor, was frequently associated with OSAS.

METHODS

This is a prospective study without intervention. Will be included, all consecutive patients referred to the Department of Pulmonology for suspected OSAS confirmed by respiratory polygraphy. Anthropometric, clinical and biological parameters needed to define the MS will be collected. MS was defined according to the IDF 2005. Assessment of cardiovascular risk related to MS will be performed by appropriate scores.

EXPECTED RESULTS

To determine the prevalence of MS in a sample of OSAS patients recruited in the Department of Pulmonology of Farhat Hached Hospital (Sousse, Tunisia). To identify risk factors independently associated with the presence of MS in patients with OSAS among the following parameters (age, gender, degree of obesity and the various parameters of OSAS severity). To assess compared cardiovascular risks according to the presence of MS by validated scales to demonstrate the impact of MS in patients with OSAS.

The pathogenesis of obstructive sleep apnea

Obstructive sleep apnea (OSA) is a major source of cardiovascular morbidity and mortality, and represents an increasing burden on health care resources. Understanding underlying pathogenic mechanisms of OSA will ultimately allow for the development of rational therapeutic strategies. In this article, we review current concepts about the pathogenesis of OSA. Specifically, we consider the evidence that the upper airway plays a primary role in OSA pathogenesis and provide a framework for modelling its biomechanical properties and propensity to collapse during sleep. Anatomical and neuromuscular factors that modulate upper airway obstruction are also discussed. Finally, we consider models of periodic breathing, and elaborate generalizable mechanisms by which upper airway obstruction destabilizes respiratory patterns during sleep. In our model, upper airway obstruction triggers a mismatch between ventilatory supply and demand. In this model, trade-offs between maintaining sleep stability or ventilation can account for a full range of OSA disease severity and expression. Recurrent arousals and transient increases in airway patency may restore ventilation between periods of sleep, while alterations in neuromuscular and arousal responses to upper airway obstruction may improve sleep stability at still suboptimal levels of ventilation.

Obstructive sleep apnea and type 2 diabetes in older adults

Both obstructive sleep apnea (OSA) and type 2 diabetes mellitus are commonly seen in older adults. Over the last decade, there has been increasing recognition that OSA is highly prevalent in persons with type 2 diabetes and related metabolic conditions such as insulin resistance and glucose intolerance. Intermittent hypoxemia and recurrent arousals in OSA trigger a repertoire of pathophysiological events, which can in turn alter glucose homeostasis and possibly increase the risk for type 2 diabetes. Conversely, there is evidence that type 2 diabetes may alter the progression and expression of sleep-disordered breathing.

Combined effects of sleep disordered breathing and metabolic syndrome on endothelial function: the Wisconsin Sleep Cohort study

STUDY OBJECTIVES

To examine the combined impact of sleep disordered breathing (SDB) and metabolic syndrome (MetS) in endothelial dysfunction.

DESIGN

Cross-sectional assessment of endothelial function, MetS and SDB status in a population-based sample.

SETTING

Community-based cohort.

PARTICIPANTS

Participants (n = 431) from the Wisconsin Sleep Cohort were studied between 2004 and 2007. MetS was defined following the National Cholesterol Education Program criteria. SDB severity was defined by the apnea-hypopnea index ([AHI] events/h of sleep) during overnight polysomnography. Fasting lipids, glucose, and insulin were measured and homeostasis model assessment was calculated to quantify insulin resistance (HOMA-IR). Multivariable linear regression was used to assess associations of brachial artery flow-mediated dilation (FMD) with SDB, MetS, and their interaction.

INTERVENTION

None.

MEASUREMENTS AND RESULTS

Participants averaged 60.2 years of age (SD 7.8 years), 44% were female, and 97% Caucasian. MetS was present in 35%; 22% had AHI ≥ 15 events/hour. Of the no-MetS group, 7% had AHI ≥ 15 events/hour. FMD (mean 5.5%; SD 3.5%) was inversely associated with age (r = -0.16, P = 0.001) and mean brachial artery diameter (r = -0.29, P < 0.001). Multivariate linear models adjusted for CVD risk factors showed that the negative association between SDB and FMD was present among subjects with MetS (β FMD(per unit log2(AHI+1)) = -0.55%, P = 0.014), but not among subjects with normal metabolic function (β = 0.13, not significant), P for interaction = 0.011.

CONCLUSION

Sleep disordered breathing and concurrent metabolic syndrome are synergistically associated with worse endothelial function. Individuals with both of these conditions appear to be at a significantly higher risk for cardiovascular disease complications.

Associations between self-reported sleep duration and sleeping disorder with concentrations of fasting and 2-h glucose, insulin, and glycosylated hemoglobin among adults without diagnosed diabetes

BACKGROUND

There is limited information from population-based investigations of the associations between sleep duration and sleep disorders and parameters of glucose homeostasis. The objective of the present study was to examine cross-sectional associations between sleep duration and sleep disordered breathing with concentrations of insulin, fasting and 2-h glucose, and HbA1c.

METHODS

Data from 11 815 adults aged ≥20 years without diagnosed diabetes (5002 with an oral glucose tolerance test) from the National Health and Nutrition Examination Survey 2005-2010 were used. Information about sleep duration (2005-2010) and sleep apnea and sleep-disordered breathing (2005-2008) was obtained via questionnaire.

RESULTS

An estimated 36.0% of participants reported sleeping ≤6 h/night, 62.0% reported sleeping 7-9 h/night, and 2.0% reported sleeping ≥10 h/night. In 2005-2008, 33.0% reported snoring ≥5 nights per week, 5.9% reported they snorted, gasped, or stopped breathing ≥5 nights/week, and 4.2% reported sleep apnea. Sleep duration was significantly associated with fasting concentrations of insulin and concentrations of HbA1c only in models that did not adjust for body mass index (BMI). Concentrations of fasting and 2-h glucose were significantly associated with sleep duration in models that adjusted only for age. Snoring frequency was positively associated with concentrations of insulin and HbA1c. Frequency of snorting or stopping breathing and sleep apnea status were associated with concentrations of insulin and of HbA1c only when BMI was not accounted for.

CONCLUSION

In a representative sample of US adults, concentrations of insulin and HbA1c were significantly associated with short sleep duration, possibly mediated by BMI.

Lingual muscle activity across sleep-wake States in rats with surgically altered upper airway

Obstructive sleep apnea (OSA) patients have increased upper airway muscle activity, including such lingual muscles as the genioglossus (GG), geniohyoid (GH), and hyoglossus (HG). This adaptation partially protects their upper airway against obstructions. Rodents are used to study the central neural control of sleep and breathing but they do not naturally exhibit OSA. We investigated whether, in chronically instrumented, behaving rats, disconnecting the GH and HG muscles from the hyoid (H) apparatus would result in a compensatory increase of other upper airway muscle activity (electromyogram, EMG) and/or other signs of upper airway instability. We first determined that, in intact rats, lingual (GG and intrinsic) muscles maintained stable activity levels when quantified based on 2 h-long recordings conducted on days 6 through 22 after instrumentation. We then studied five rats in which the tendons connecting the GH and HG muscles to the H apparatus were experimentally severed. When quantified across all recording days, lingual EMG during slow-wave sleep (SWS) was modestly but significantly increased in rats with surgically altered upper airway [8.6 ± 0.7% (SE) vs. 6.1 ± 0.7% of the mean during wakefulness; p = 0.012]. Respiratory modulation of lingual EMG occurred mainly during SWS and was similarly infrequent in both groups, and the incidence of sighs and central apneas also was similar. Thus, a weakened action of selected lingual muscles did not produce sleep-disordered breathing but resulted in a relatively elevated activity in other lingual muscles during SWS. These results encourage more extensive surgical manipulations with the aim to obtain a rodent model with collapsible upper airway.

Increased risk of benign prostate hyperplasia in sleep apnea patients: a nationwide population-based study

Background

Sleep apnea (SA) is a common sleep disorder characterized by chronic intermittent hypoxia (IH). Chronic IH induces systemic inflammatory processes, which can cause tissue damage and contribute to prostatic enlargement. The purpose of this study was to evaluate the association between benign prostate hyperplasia (BPH) and SA in a Taiwanese population.

Methods

The study population was identified from Taiwan’s National Health Insurance Research Database (NHIRD) and contained 202 SA patients and 1010 control patients. The study cohort consisted of men aged ≥30 years who were newly diagnosed with SA between January 1997 and December 2005. Each patient was monitored for 5 years from the index date for the development of BPH. A Cox regression analysis was used to calculate the hazard ratios (HRs) for BPH in the SA and control patients.

Results

During the 5-year follow-up, 18 SA patients (8.9%) and 32 non-SA control patients (3.2%) developed BPH. The adjusted HR for BPH was 2.35-fold higher in the patients with SA than in the control patients (95% confidence interval (CI) 1.28–4.29, P<.01). We further divided the SA patients into 4 age groups. After adjusting for potential confounding factors, the highest adjusted HR for BPH in the SA patients compared with the control patients was 5.59 (95% CI = 2.19–14.31, P<.001) in the patients aged between 51 and 65 years.

Conclusion

Our study results indicate that patients with SA are associated with increased longitudinal risk of BPH development, and that the effects of SA on BPH development are age-dependent.