Obstructive sleep apnea: a cardiometabolic risk in obesity and the metabolic syndrome. J Am Coll Cardiol. 2013;62:569-576. [PMID: 23770180 DOI: 10.1016/j.jacc.2013.05.045]

Self-reported sleep in late pregnancy in relation to birth size and fetal distress: the E Moe, Māmā prospective cohort study

OBJECTIVES

To explore associations between features of sleep during pregnancy and adverse outcomes for the infant.

SETTING

E Moe, Māmā is a cohort study in Aotearoa/New Zealand that investigates self-reported sleep and maternal health in late pregnancy and the postpartum period.

PARTICIPANTS

Women (N=633; 194 Māori) reported detailed information on their sleep duration, quality, disturbances, disorders (snoring, breathing pauses, twitching legs, restless legs) and daytime sleepiness between 35 and 37 weeks gestation.

OUTCOME MEASURES

Birthweight and fetal distress during labour were extracted from medical records. Associations between each sleep variable and small or large for gestational age (SGA/LGA) using customised birthweight centile or fetal distress were estimated using multinomial/logistic regression, controlling for potential confounders. Secondary analyses considered differences in associations between Māori and non-Māori women.

RESULTS

There was some indication that breathing pauses (a measure of sleep apnoea) were associated with both SGA (OR 2.8, 95% CI 0.9 to 9.0, p=0.08) and LGA (OR 2.0, 95% CI 0.7 to 5.7, p=0.20), with the association for LGA being stronger when only pregnancy-onset breathing pauses were considered (OR 3.5, 95% CI 1.3 to 9.6, p=0.01). There was also some evidence that pregnancy-onset leg twitching (OR 3.3, 95% CI 1.1 to 10.0, p=0.03) and frequent sleep disturbance due to feeling too hot or too cold (OR 1.7, 95% CI 0.9 to 3.6, p=0.13) were associated with higher risk of fetal distress. Other sleep measures, including snoring, were not associated with SGA, LGA or fetal distress. Many of the associations we observed were considerably stronger in Māori compared with non-Māori women.

CONCLUSIONS

We did not find evidence of previously reported associations between snoring and SGA. Our findings tentatively suggest that self-reported breathing pauses and leg twitching in late pregnancy are associated with infant outcomes, and highlight ethnic inequalities.

Psoriasis and sleep disorders: A systematic review

Psoriasis is an immune-mediated chronic inflammatory disorder which manifests as dermatologic lesions, and psoriatic arthritis (PsA) in about 30% of cases. Psoriasis is associated with multiple comorbidities including metabolic syndrome, hypertension, diabetes, cardiovascular events, obesity and psychiatric disorders, which can all affect the course of sleep disorders. A systematic review of the literature on the relationship between psoriasis, PsA, and formal sleep disorders identified 33 studies. There is an increased prevalence of obstructive sleep apnea (OSA) with 36%-81.8% prevalence in psoriasis versus 2%-4% in the general population. There was also an increase in the prevalence of restless legs syndrome of 15.1%-18% in psoriasis versus 5%-10% in European and North American samples. The wide variety of insomnia criteria used in studies resulted in an insomnia prevalence of 5.9%-44.8% in psoriasis, which is insufficient to show an elevated prevalence when the general population has a 10% prevalence of chronic insomnia and 30-35% prevalence of transient insomnia. There is evidence that symptoms of insomnia in psoriasis are directly mediated by pruritus and pain. Treatments that decrease the cutaneous symptoms in psoriasis were successful in mitigating insomnia, but did not show improvements in OSA where the relationship with psoriasis is multifactorial.

The association between obstructive sleep apnea and metabolic syndrome: a systematic review and meta-analysis

Background

Obstructive sleep apnea (OSA) is characterized by repeated episodes of obstruction of the upper airway. Numerous studies have indicated a relationship between OSA and metabolic syndrome (MS), but the results remain debatable. We aimed to perform a systematic review and meta-analysis to evaluate the association between OSA and MS.

Methods

We searched electronic databases (PubMed, EMBASE, and ISO Web of Knowledge) up to September 2014 with English-language restriction. Cross-sectional, case–control, and cohort studies in which the presence of OSA was assessed by objective measurements, the exposure of interest was OSA, and the outcome of interest was the presence (or incidence) of MS were included. The adjusted odds ratios (ORs) (or relative risk) and 95 % confidence intervals (CIs) were extracted and pooled. Sensitivity analyses were conducted, and heterogeneity and publication bias were assessed.

Results

Overall, 15 cross-sectional (2456 patients with OSA and 1705 subjects without OSA), five case–control (1156 OSA patients and 404 controls), and no cohort studies were included. The pooled ORs of MS in individuals with OSA for cross-sectional and case–control studies were 2.87 (95 % CI: 2.41–3.42) and 2.56 (95 % CI: 1.98–3.31), respectively. There was clinically unimportant (I² = 20 %) and moderate (I² = 35 %) between-study heterogeneity of the analysis. The pooled crude ORs of MS in individuals with mild and moderate-to-severe OSA was 2.39 (95 % CI: 1.65–3.46) and 3.45 (95 % CI: 2.33–5.12), respectively, and there was substantial heterogeneity in the meta-analyses (I² = 53 % and I² = 63 %, respectively). However, no evidence of publication bias was detected.

Conclusions

OSA is shown to be associated with MS, although causality between these two factors has not been demonstrated yet. Future cohort and randomized controlled studies are needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0102-3) contains supplementary material, which is available to authorized users.

Association of sleep characteristics with atrial fibrillation: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Population-based studies have linked measures of sleep disordered breathing to nocturnally occurring atrial fibrillation (AF) episodes. Whether measures of sleep disordered breathing and sleep quality are associated with prevalent AF has not been studied in an unselected population. We investigated the cross-sectional association with prevalent AF of objectively collected prespecified measures of overnight sleep breathing disturbances, sleep stage distributions, arousal and sleep duration.

METHODS

AF prevalence, defined by diagnosis codes, study electrocardiography and sleep study were examined among Multi-Ethnic Study of Atherosclerosis (MESA) participants who underwent polysomnography in the MESA Sleep Study (n=2048).

MEASUREMENTS AND MAIN RESULTS

Higher apnoea hypopnoea index (AHI) was associated with increased odds of AF, although the significance was attenuated after full adjustment for covariates including prevalent cardiovascular disease (OR: 1.22 (0.99 to 1.49) per SD (17/h), p=0.06). Analyses of sleep architecture measures and AF revealed significantly lower odds of AF associated with longer duration of slow wave sleep (OR: 0.66 (0.5 to 0.89) per SD (34 min), p=0.01) which persisted after additionally adjusting for AHI (OR: 0.68 (0.51 to 0.92), p=0.01). Higher sleep efficiency was significantly associated with lower likelihood of AF but the significance was lost when adjusted for AHI. No significant association was present between sleep duration and AF. In a model including AHI and arousal index, the association between AHI and AF was strengthened (AHI: OR 1.49 (1.15 to 1.91) per SD, p=0.002) and a significant inverse association between arousal index and AF was observed (OR 0.65 (0.50 to 0.86) per SD (12/h), p=0.005).

CONCLUSIONS

In a study of a large multiethnic population, AF was associated with AHI severity, and was more common in individuals with poor sleep quality as measured by reduced slow wave sleep time, a finding that was independent of AHI.

Uncontrolled blood pressure and risk of sleep apnea among blacks: findings from the Metabolic Syndrome Outcome (MetSO) study

Uncontrolled blood pressure (BP) is linked to increased risk of obstructive sleep apnea (OSA). However, few studies have assessed the impact of this relationship among blacks with metabolic syndrome (MetS). Data for this study were collected from 1035 blacks (mean age=62±13 years) enrolled in the Metabolic Syndrome Outcome study. Patients with a score ⩾6 on the Apnea Risk Evaluation System were considered at risk for OSA. Of the sample, 77.1% were low-to-high OSA risk and 92.3% were hypertensive, of which 16.8% had uncontrolled BP levels. Analysis also showed that 60.4% were diabetic, 8.9% had a stroke history, 74.3% had dyslipidemia, 69.8% were obese and 30.9% had a history of heart disease. Logistic regression analyses were employed to investigate associations between uncontrolled BP and OSA risk, while adjusting for known covariates. Findings showed that uncontrolled BP independently increased the odds of OSA risk twofold (odds ratio=2.02, 95% confidence interval=1.18-3.48, P<0.05). In conclusion, our findings show that uncontrolled BP was associated with a twofold greater risk of OSA among blacks, suggesting that those with MetS and who have uncontrolled BP should be screened for the presence of OSA.

Diet and exercise improve chemoreflex sensitivity in patients with metabolic syndrome and obstructive sleep apnea

OBJECTIVE

Chemoreflex hypersensitity was caused by obstructive sleep apnea (OSA) in patients with metabolic syndrome (MetS). This study tested the hypothesis that hypocaloric diet and exercise training (D+ET) would improve peripheral and central chemoreflex sensitivity in patients with MetS and OSA.

METHODS

Patients were assigned to: (1) D+ET (n = 16) and (2) no intervention control (C, n = 8). Minute ventilation (VE, pre-calibrated pneumotachograph) and muscle sympathetic nerve activity (MSNA, microneurography) were evaluated during peripheral chemoreflex sensitivity by inhalation of 10% O2 and 90% N2 with CO2 titrated and central chemoreflex by 7% CO2 and 93% O2 for 3 min at study entry and after 4 months.

RESULTS

Peak VO2 was increased by D+ET; body weight, waist circumference, glucose levels, systolic/diastolic blood pressure, and apnea-hypopnea index (AHI) (34 ± 5.1 vs. 18 ± 3.2 events/h, P = 0.04) were reduced by D+ET. MSNA was reduced by D+ET at rest and in response to hypoxia (8.6 ± 1.2 vs. 5.4 ± 0.6 bursts/min, P = 0.02), and VE in response to hypercapnia (14.8 ± 3.9 vs. 9.1 ± 1.2 l/min, P = 0.02). No changes were found in the C group. A positive correlation was found between AHI and MSNA absolute changes (R = 0.51, P = 0.01) and body weight and AHI absolute changes (R = 0.69, P < 0.001).

CONCLUSIONS

Sympathetic peripheral and ventilatory central chemoreflex sensitivity was improved by D+ET in MetS+OSA patients, which may be associated with improvement in sleep pattern.

Translational approaches to understanding metabolic dysfunction and cardiovascular consequences of obstructive sleep apnea

Obstructive sleep apnea (OSA) is known to be independently associated with several cardiovascular diseases including hypertension, myocardial infarction, and stroke. To determine how OSA can increase cardiovascular risk, animal models have been developed to explore the underlying mechanisms and the cellular and end-organ targets of the predominant pathophysiological disturbance in OSA-intermittent hypoxia. Despite several limitations in translating data from animal models to the clinical arena, significant progress has been made in our understanding of how OSA confers increased cardiovascular risk. It is clear now that the hypoxic stress associated with OSA can elicit a broad spectrum of pathological systemic events including sympathetic activation, systemic inflammation, impaired glucose and lipid metabolism, and endothelial dysfunction, among others. This review provides an update of the basic, clinical, and translational advances in our understanding of the metabolic dysfunction and cardiovascular consequences of OSA and highlights the most recent findings and perspectives in the field.

CPAP therapy induces favorable short-term changes in epicardial fat thickness and vascular and metabolic markers in apparently healthy subjects with obstructive sleep apnea-hypopnea syndrome (OSAHS)

BACKGROUND

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is an independent risk factor for hypertension, coronary artery disease, and diabetes mellitus. Epicardial fat has been recently recognized as a new risk factor and active participant on cardiometabolic risk. The aim of this study was to assess an independent relationship between sleep apnea severity, metabolic and vascular markers, and epicardial fat, at baseline and after 3 months of continuous positive airway pressure (CPAP) therapy.

MATERIALS AND METHOD

Our study group consisted of 48 patients with suspected OSAHS and no prior history of cardiovascular disease or diabetes mellitus. All patients underwent full overnight polysomnography. Thickness of epicardial and visceral adipose tissue, brachial artery flow-mediated dilation (FMD), carotid intima media thickness (cIMT), pulse wave velocity (PWV), plasma C-reactive protein (CRP) levels, fasting glucose levels, HbA1c, homeostatic model assessment of insulin resistance index (HOMA), and lipid profile were measured at baseline and after 3 months of CPAP use in patients with moderate to severe OSAHS.

RESULTS

In OSAHS patients (Apnea-hypopnea index (AHI) ≥15/h, N = 28), epicardial fat correlated with fasting glucose (rho = 0.406, p = 0.04) and HOMA (rho = 0.525, p = 0.049) but was not associated with visceral fat (rho = 0.126, p = 0.595). Epicardial adipose tissue (EAT) (p = 0.022) increased across AHI severity along with PWV (p = 0.045) and carotid intima media thickness (IMT) (p = 0.034) while FMD (p = 0.017) decreased. Therapy with CPAP reduced both epicardial (p < 0.001) and visceral fat (p = 0.001). Alterations in epicardial fat across the follow-up were associated with changes in PWV (p = 0.026) and HOMA (p = 0.037) independently of major confounders.

CONCLUSIONS

Epicardial fat thickness was associated with OSA severity and may be an additional marker of cardiovascular risk as well as of future diabetes in these patients. CPAP therapy reduced epicardial fat, suggesting its potentially beneficial role in reducing cardiometabolic risk in OSA patients.

Sleep-disordered breathing and resistant hypertension

Hypertension is a highly prevalent problem worldwide, affecting at least one third of the adult general population. Although the exact prevalence is uncertain, it is estimated that at least 15% to 20% of individuals with hypertension have resistant hypertension. Resistant hypertension has been shown to predict more adverse cardiovascular and renal outcomes. In 2003, the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure recognized obstructive sleep apnea (OSA) as an important cause of secondary hypertension. A large body of epidemiologic evidence has linked OSA to resistant hypertension, nondipping nocturnal blood pressure, as well as target organ damage, including left ventricular hypertrophy, arterial stiffness, and microalbuminuria. The importance of OSA as a risk factor for the development of hypertension independent of other confounding factors also was observed in a prospective longitudinal study. More importantly, OSA predicts an increased risk of adverse cardiovascular outcomes, mortality, and sudden cardiac death. This article discusses the associations between OSA and resistant hypertension and reviews the latest understanding on the pathophysiologic mechanisms of hypertension in OSA. Nocturnal continuous positive airway pressure therapy is regarded as the standard treatment for OSA. Prospective randomized controlled trials and meta-analyses of prospective randomized controlled trials within the past 10 years that have examined the effects of continuous positive airway pressure therapy on blood pressure control in patients with OSA with or without hypertension are reviewed and summarized. The majority of the trials suggest a modest but significant benefit on blood pressure control with continuous positive airway pressure therapy. Whether continuous positive airway pressure therapy may improve hard outcomes of patients with OSA and resistant hypertension warrants further investigation.

Prolonged REM sleep restriction induces metabolic syndrome-related changes: Mediation by pro-inflammatory cytokines

Chronic sleep restriction in human beings results in metabolic abnormalities, including changes in the control of glucose homeostasis, increased body mass and risk of cardiovascular disease. In rats, 96h of REM sleep deprivation increases caloric intake, but retards body weight gain. Moreover, this procedure increases the expression of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), which may be involved with the molecular mechanism proposed to mediate insulin resistance. The goal of the present study was to assess the effects of a chronic protocol of sleep restriction on parameters of energy balance (food intake and body weight), leptin plasma levels and its hypothalamic receptors and mediators of the immune system in the retroperitoneal adipose tissue (RPAT). Thirty-four Wistar rats were distributed in control (CTL) and sleep restriction groups; the latter was kept onto individual narrow platforms immersed in water for 18h/day (from 16:00h to 10:00h), for 21days (SR21). Food intake was assessed daily, after each sleep restriction period and body weight was measured daily, after the animals were taken from the sleep deprivation chambers. At the end of the 21day of sleep restriction, rats were decapitated and RPAT was obtained for morphological and immune functional assays and expression of insulin receptor substrate 1 (IRS-1) was assessed in skeletal muscle. Another subset of animals was used to evaluate blood glucose clearance. The results replicated previous findings on energy balance, e.g., increased food intake and reduced body weight gain. There was a significant reduction of RPAT mass (p<0.001), of leptin plasma levels and hypothalamic leptin receptors. Conversely, increased levels of TNF-α and IL-6 and expression of phosphorylated NFκ-β in the RPAT of SR21 compared to CTL rats (p<0.01, for all parameters). SR21 rats also displayed reduced glucose clearance and IRS-1 expression than CTL rats (p<0.01). The present results indicated that 21days of sleep restriction by the platform method induced metabolic syndrome-related alterations that may be mediated by inflammation of the RPAT.

Obstructive sleep apnoea syndrome

Obstructive sleep apnoea syndrome (OSAS) is a common clinical condition in which the throat narrows or collapses repeatedly during sleep, causing obstructive sleep apnoea events. The syndrome is particularly prevalent in middle-aged and older adults. The mechanism by which the upper airway collapses is not fully understood but is multifactorial and includes obesity, craniofacial changes, alteration in upper airway muscle function, pharyngeal neuropathy and fluid shift towards the neck. The direct consequences of the collapse are intermittent hypoxia and hypercapnia, recurrent arousals and increase in respiratory efforts, leading to secondary sympathetic activation, oxidative stress and systemic inflammation. Excessive daytime sleepiness is a burden for the majority of patients. OSAS is also associated with cardiovascular co-morbidities, including hypertension, arrhythmias, stroke, coronary heart disease, atherosclerosis and overall increased cardiovascular mortality, as well as metabolic dysfunction. Whether treating sleep apnoea can fully reverse its chronic consequences remains to be established in adequately designed studies. Continuous positive airway pressure (CPAP) is the primary treatment modality in patients with severe OSAS, whereas oral appliances are also widely used in mild to moderate forms. Finally, combining different treatment modalities such as CPAP and weight control is beneficial, but need to be evaluated in randomized controlled trials. For an illustrated summary of this Primer, visit: http://go.nature.com/Lwc6te.

Obstructive sleep apnea is independently associated with inflammation and insulin resistance, but not with blood pressure, plasma catecholamines, and endothelial function in obese subjects

OBJECTIVES

Obstructive sleep apnea (OSA) is associated with an increased risk of cardiovascular disease (CVD). Several of the proposed mechanisms for the development of CVD in OSA are similar to those proposed for the increased risk of CVD in obesity, so that it is difficult to determine the influence of OSA on these pathogenic mechanisms in obese individuals. The aim of this study was to evaluate the relationship of OSA with endothelial function, oxidative stress, inflammatory biomarkers, metabolic profile, sympathetic nervous system activity, and blood pressure (BP) in obese individuals.

METHODS

This cross-sectional study included 53 obese adults (28 women). Sleep study was performed with WatchPAT 200 (Itamar Medical, Caesarea, Israel) and the diagnosis of OSA was made when apnea-hypopnea index (AHI) ≥5 events/h (n = 33). All participants underwent evaluation of: body adiposity, BP, plasma catecholamines, high sensitivity C-reactive protein (hs-CRP), adiponectin, malondialdehyde, glucose, insulin, lipid profile, and endothelial function (EndoPAT 2000).

RESULTS

In univariate analysis, participants with OSA compared with those without OSA exhibited higher values of neck circumference, glucose, noradrenaline, and systolic BP. After adjustment for confounders, including adiposity, only glucose and hs-CRP were significantly higher in OSA patients. In correlation analysis, after controlling for confounders, AHI was positively and significantly associated with neck circumference and hs-CRP, while minimum O2 saturation was associated negatively and significantly with neck circumference, insulin and homeostatic model assessment-insulin resistance (HOMA-IR).

CONCLUSIONS

The present study suggests that in obese individuals OSA is independently associated with inflammation and insulin resistance, but not with BP, plasma catecholamines and endothelial function.

Predictors of Obstructive Sleep Apnea Risk among Blacks with Metabolic Syndrome

INTRODUCTION

Identification of risk factors for obstructive sleep apnea (OSA) is important to enable comprehensive intervention to reduce OSA-related cardiovascular disease (CVD). The metabolic syndrome outcome study (MetSO) provides a unique opportunity to address these factors. This study investigated risk of OSA among blacks with metabolic syndrome.

METHODS

The present study utilized data from MetSO, an NIH-funded cohort study of blacks with metabolic syndrome. A total of 1,035 patients provided data for the analysis. These included sociodemographic factors, health risks, and medical history. Physician-diagnosed conditions were obtained using an electronic medical record system (Allscripts, Sunrise Enterprise). Patients were diagnosed with metabolic syndrome using criteria articulated in the joint interim statement for harmonizing the metabolic syndrome. Patients with a score ≥6 on the Apnea Risk Evaluation System (ARES) questionnaire were considered at risk for OSA. Obesity is defined by body mass index (BMI ≥ 30 kg/m2).

RESULTS

Of the 1,035 patients screened in the MetSO cohort, 48.9% were at high risk for OSA. Using multivariate-adjusted logistic regression analysis, we observed that obesity was the strongest predictor of OSA risk (OR=1.59, 95%CI=1.24-2.04, p<0.0001). This finding remained significant even after adjustment for known covariates including blood pressure, low-density lipoprotein, high-density lipoprotein, and glucose levels (OR=1.44, 95%CI=1.11-1.86, p<0.001).

CONCLUSION

Blacks in the MetSO cohort are at greater OSA risk, relative to the adult population in developed countries. Consistent with previous observations, obesity proved the strongest independent predictor of OSA risk among blacks with metabolic syndrome.

Uncoupling protein-2 mRNA expression in mice subjected to intermittent hypoxia

OBJECTIVE

To investigate the effect of intermittent hypoxia-a model of obstructive sleep apnea (OSA)-on pancreatic expression of uncoupling protein-2 (UCP2), as well as on glycemic and lipid profiles, in C57BL mice.

METHODS

For 8 h/day over a 35-day period, male C57BL mice were exposed to intermittent hypoxia (hypoxia group) or to a sham procedure (normoxia group). The intermittent hypoxia condition involved exposing mice to an atmosphere of 92% N and 8% CO2 for 30 s, progressively reducing the fraction of inspired oxygen to 8 ± 1%, after which they were exposed to room air for 30 s and the cycle was repeated (480 cycles over the 8-h experimental period). Pancreases were dissected to isolate the islets. Real-time PCR was performed with TaqMan assays.

RESULTS

Expression of UCP2 mRNA in pancreatic islets was 20% higher in the normoxia group than in the hypoxia group (p = 0.11). Fasting serum insulin was higher in the hypoxia group than in the normoxia group (p = 0.01). The homeostasis model assessment of insulin resistance indicated that, in comparison with the control mice, the mice exposed to intermittent hypoxia showed 15% lower insulin resistance (p = 0.09) and 21% higher pancreatic β-cell function (p = 0.01). Immunohistochemical staining of the islets showed no significant differences between the two groups in terms of the area or intensity of α- and β-cell staining for insulin and glucagon.

CONCLUSIONS

To our knowledge, this is the first report of the effect of intermittent hypoxia on UCP2 expression. Our findings suggest that UCP2 regulates insulin production in OSA. Further study of the role that UCP2 plays in the glycemic control of OSA patients is warranted.

Dietary and Behavioral Factors Associated with Diet Quality among Low-income Overweight and Obese African American Women

OBJECTIVES

The goal of this research was to assess the roles of demographic and home food environment characteristics on diet quality measured with the U.S. Department of Agriculture's Healthy Eating Index (HEI) in a population of low-income overweight and obese African American women.

DESIGN

Cross-sectional analysis of baseline data.

SETTING

A community-based study of low-income overweight and obese African American women.

SUBJECTS

Participants enrolled in the Healthy Homes/Healthy Families study including a home environment survey (e.g., food availability, food practices and social support) and 24-hour recall dietary data collected on one weekday and one weekend day (n = 198).

RESULTS

In multivariate regression analyses, demographic characteristics were not significantly associated with diet quality; however, several home food environment characteristics were significantly associated with higher quality diets, including healthy shopping (e.g., regularly purchasing fresh fruits and vegetables), selecting healthy beverages (e.g., without added sugar), healthy food preparation, and serving behaviors. Eating while watching television was associated with lower quality diets. Nearly 33% (p < 0.001) of the variance in HEI total score was explained by the home food environment factors, far surpassing that explained by demographic characteristics (3.5%, p = 0.21).

CONCLUSIONS

Interventions targeting the home food environment may improve overall diet quality in low-income overweight African American populations.

Lifestyle effects on hematopoiesis and atherosclerosis

Diet, exercise, stress, and sleep are receiving attention as environmental modifiers of chronic inflammatory diseases, including atherosclerosis, the culprit condition of myocardial infarction and stroke. Accumulating data indicate that psychosocial stress and a high-fat, high-cholesterol diet aggravate cardiovascular disease, whereas regular physical activity and healthy sleeping habits help prevent it. Here, we raise the possibility that inflammation-associated leukocyte production plays a causal role in lifestyle effects on atherosclerosis progression. Specifically, we explore whether and how potent real-life disease modifiers influence hematopoiesis' molecular and cellular machinery. Lifestyle, we hypothesize, may rearrange hematopoietic topography, diverting production from the bone marrow to the periphery, thus propagating a quantitative and qualitative drift of the macrophage supply chain. These changes may involve progenitor-extrinsic and intrinsic communication nodes that connect organ systems along neuroimmune and immunometabolic axes, ultimately leading to an altered number and phenotype of lesional macrophages. We propose that, in conjunction with improved public health policy, future therapeutics could aim to modulate the quantitative and qualitative output, as well as the location, of the hematopoietic tree to decrease the risk of atherosclerosis complications.

Tension-type headache associated with obstructive sleep apnea: a nationwide population-based study

BACKGROUND

There is still controversy regarding the association between primary headaches and obstructive sleep apnea. We explored the relationship between tension-type headache (TTH) and obstructive sleep apnea (OSA) using a large nationwide population-based data set in Taiwan.

METHODS

We identified 4759 patients diagnosed with OSA from the Taiwan Longitudinal Health Insurance Database, based on polysomnography, as the OSA group. We then randomly selected 19036 subjects without OSA, matched by sex and age, to serve as the non-OSA group. The multivariate Cox proportional hazards model with matching for age and sex was used to assess the possible associations between TTH and OSA among the patients.

RESULTS

The prevalence of TTH was 10.2% among OSA patients and 7.7% among non-OSA patients (p < 0.001). The multivariate Cox proportional hazards model revealed patients with OSA were more likely to have TTH (hazard ratio, 1.18; 95% CI, 1.06-1.31) (p = 0.003) than patients in the non-OSA group.

CONCLUSION

Patients with OSA had a higher likelihood of developing TTH than patients in the non-OSA group. Further studies of physiological patterns between OSA and TTH are needed to confirm the study findings.

Potential underdiagnosis of obstructive sleep apnoea in the cardiology outpatient setting

INTRODUCTION

Consistent evidence suggests that obstructive sleep apnoea (OSA) is associated with increased cardiovascular risk. However, it is unclear whether OSA is underdiagnosed in the cardiology outpatient setting. In the present study, we prospectively evaluated the potential underdiagnosis of OSA in several subspecialties from a tertiary cardiology university hospital.

METHODS

Consecutive outpatients from five subspecialties (hypertension, coronary, arrhythmia, heart failure (HF), valvular heart disease) were studied. We performed anthropometric measurements, assessed the risk of OSA using the Berlin Questionnaire and evaluated the prior diagnosis and treatment for OSA. In a subset of patients randomly selected, we performed portable sleep monitoring to objectively evaluate the presence of OSA (defined by an apnoea-hypopnoea index ≥15 events/h of sleep).

RESULTS

We evaluated 500 patients (100 from each subspecialty). The mean age and body mass index (BMI) were 59±13 years and 28.2±5.3 kg/m(2), respectively. We found that 51.6% (258 patients) had a high risk for OSA (Berlin Questionnaire). However, only 13 (3.1%) of these patients had a previous diagnosis of OSA. Of those, only six patients were receiving specific OSA treatment. Fifty patients (10 from each specialty) participated in sleep studies. No differences were found in patients who underwent sleep monitoring and those who did not. We found a high frequency of OSA (66%), varying from 50% (hypertension group) to 80% (HF group).

CONCLUSIONS

Despite significant scientific evidence pointing to OSA as an emerging cardiovascular risk factor, OSA is still underdiagnosed in several cardiology subspecialties.

Survival, hypothalamic obesity, and neuropsychological/psychosocial status after childhood-onset craniopharyngioma: newly reported long-term outcomes

BACKGROUND

Quality of life (QoL) and long-term prognosis are frequently, and often severely, impaired in craniopharyngioma (CP) patients. Knowledge of risk factors for long-term outcome is important for optimization of treatment.

METHODS

Overall survival (OS) and progression-free survival (PFS), body mass index (BMI), neuropsychological status (EORTCQLQ-C30, MFI-20), and psychosocial status were analyzed in 261 patients with childhood-onset CP diagnosed before 2000 and longitudinally observed in HIT-Endo.

RESULTS

Twenty-year OS was lower (P = .006) in CP with hypothalamic involvement (HI) (n = 132; 0.84 ± 0.04) when compared with CP without HI (n = 82; 0.95 ± 0.04). OS was not related to degree of resection, sex, age at diagnosis, or year of diagnosis (before/after 1990). PFS (n = 168; 0.58 ± 0.05) was lower in younger patients (<5 y at diagnosis) (n = 30; 0.39 ± 0.10) compared with patients aged 5-10 years (n = 66; 0.52 ± 0.08) and older than 10 years (n = 72; 0.77 ± 0.06) at diagnosis. PFS was not associated with HI, degree of resection, or sex. HI led to severe weight gain during the first 8-12 years of follow-up (median BMI increase: +4.59SD) compared with no HI (median increase: +1.20SD) (P = .00). During >12 years of follow-up, patients with HI presented no further increase in BMI. QoL in CP patients with HI was impaired by obesity, physical fatigue, reduced motivation, dyspnea, diarrhea, and nonoptimal psychosocial development.

CONCLUSIONS

OS and QoL are impaired by HI in long-term survivors of CP. HI is associated with severe obesity, which plateaus after 12 years. OS/PFS are not related to degree of resection, but gross-total resection should be avoided in cases of HI to prevent further hypothalamic damage, which exacerbates sequelae.

Sudden cardiac death and obesity

For individuals and the society as a whole, the increased risk of sudden cardiac death in obese patients is becoming a major challenge, especially since obesity prevalence has been increasing steadily around the globe. Traditional risk factors and obesity often coexist. Hypertension, diabetes, obstructive sleep apnea and metabolic syndrome are well-known risk factors for CV disease and are often present in the obese patient. Although the bulk of evidence is circumstantial, sudden cardiac death and obesity share common traditional CV risk factors. Structural, functional and metabolic factors modulate and influence the risk of sudden cardiac death in the obese population. Other risk factors such as left ventricular hypertrophy, increased number of premature ventricular complexes, altered QT interval and reduced heart rate variability are all documented in both obese and sudden cardiac death populations. The present review focuses on out-of-hospital sudden cardiac death and potential mechanisms leading to sudden cardiac death in this population.

Update on the use of portable monitoring system for the diagnosis of sleep apnea in specific population

The prevalence and severity of obstructive sleep apnea (OSA) is higher in specific population: children, elderly, obese and patients with pulmonary and cardiovascular diseases, compared to the general population. OSA is associated with greater morbidity and mortality in these patients. Although full-night polysomnography is still the gold standard diagnostic sleep study for OSA, it is a time consuming, expensive and technically demanding exam. Over the last few years, there is growing evidence on the use of portable monitors (PM) as an alternative for the diagnosis of OSA. These devices were developed specially for sleep evaluation at home, at a familiar environment, with easy self-application of monitoring, unattended. The use of PM is stablished for populations with high pre-test probability of OSA. However, there is a lack of studies on the use of PM in age extremes and patients with comorbidities. The purpose of this review is to present the studies that evaluated the use of PM in specific population, as well as to describe the advantages, limitations and applications of these devices in this particular group of patients. Although the total loss rate of recordings is variable in different studies, the agreement with full-night polysomnography justifies the use of PM in this population.

Intermittent hypoxemia and OSA: implications for comorbidities

OSA is a common chronic disorder that is associated with significant morbidity and mortality including cardiovascular, metabolic, and neurocognitive disease and increased cancer-related deaths. OSA is characterized by recurrent episodes of apneas and hypopneas associated with repetitive episodes of intermittent hypoxemia, intrathoracic pressure changes, and arousals. Intermittent hypoxemia (IH) is now being recognized as a potential major factor contributing to the pathogenesis of OSA-related comorbidities. OSA-related high-frequency IH is characterized by cycles of hypoxemia with reoxygenation that is distinctly different than sustained low-frequency hypoxia and contributes to ischemia-reperfusion injury. Data from both animal and human studies support mechanistic links between IH and its adverse impact at the tissue level. IH promotes oxidative stress by increased production of reactive oxygen species and angiogenesis, increased sympathetic activation with BP elevation, and systemic and vascular inflammation with endothelial dysfunction that contributes to diverse multiorgan chronic morbidity and mortality affecting cardiovascular disease, metabolic dysfunction, cognitive decline, and progression of cancer. Data from observational studies in large population groups also support the role for hypoxia in the pathogenesis of OSA comorbidity. Treatment with CPAP to reverse OSA-related symptoms and comorbidities has been shown to provide variable benefit in some but not all patient groups. Early treatment with CPAP makes intuitive sense to promote maximal functional recovery and minimize residual injury. More studies are needed to determine the interacting effects of IH and obesity, differential effects of both short-term and long-term hypoxemia, and the effect of CPAP treatment.

HIV-associated neurocognitive disorders: the relationship of HIV infection with physical and social comorbidities

The prevalence of HIV (human immunodeficiency virus) associated neurocognitive disorders (HAND) will undoubtedly increase with the improved longevity of HIV-infected persons. HIV infection, itself, as well as multiple physiologic and psychosocial factors can contribute to cognitive impairment and neurologic complications. These comorbidities confound the diagnosis, assessment, and interventions for neurocognitive disorders. In this review, we discuss the role of several key comorbid factors that may contribute significantly to the development and progression of HIV-related neurocognitive impairment, as well as the current status of diagnostic strategies aimed at identifying HIV-infected individuals with impaired cognition and future research priorities and challenges.

Obstructive sleep apnea: An interdisciplinary challenge for otorhinolaryngologists

Otolaryngologists play a pivotal role in the diagnosis and management of sleep-related breathing disorders (SRBD) in both adults and children. Otolaryngologists are often the first medical specialists to be contacted by patients with complaints as snoring, episodic sleep apnea observed by the bed partners with or without reported excessive daytime sleepiness and therefore emerge as important gatekeepers of the general health of an individual by means of an active preventive, and in many cases therapeutic, role. Comprehensive diagnosis and treatment of SRBD requires a team approach and hence building interdisciplinary teams with other involved relevant specialties is necessary from the patients’ perspective.

Obstructive sleep apnea and optic neuropathy: is there a link?

Over the last decade, there has been an emerging interest in the link between obstructive sleep apnea (OSA) and ocular health. Though the evidence for OSA playing a role in cerebrovascular disease risk seems clear, the same cannot be said for optic neuropathies. The association between OSA and glaucoma or non-arteritic anterior ischemic optic neuropathy (NAION) has been postulated to be secondary to direct hypoxia or mechanisms of optic nerve head vascular dysregulation. Papilledema and increased intracranial pressure have also been reported in OSA and are thought to be due to increased cerebral perfusion pressure and cerebral venous dilation secondary to hypoxia and hypercapnia. This article reviews the evidence for possible pathophysiological links between OSA and optic nerve pathology. The epidemiologic and clinical evidence for an association, direct or indirect, between OSA and glaucoma, non-arteritic anterior ischemic optic neuropathy (NAION), and papilledema or idiopathic intracranial hypertension is presented.

Leptin and leptin receptor gene polymorphisms in obstructive sleep apnea: a HuGE review and meta-analysis

BACKGROUND

Several epidemiological studies have been conducted to examine the association between leptin and leptin receptor (LEPR) gene polymorphisms and risk of obstructive sleep apnea (OSA). However, the results remain conflicting rather than conclusive.

OBJECTIVE

The aim of this study was to investigate associations of leptin and LEPR polymorphisms and risk of OSA.

METHODS

We carried out a search in MEDLINE, EMBASE, and Chinese National Knowledge Infrastructure (CNKI) databases for relevant studies. Data were extracted using a standardized form and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the strength of the association.

RESULTS

Overall, no statistically significant association of OSA risk and polymorphisms of Gln233Arg, Lys109Arg, Lys656Asn, 19A/G, Pro1019Arg, and 2548G/A was found. However, in the stratified analysis by ethnicity, Gln233Arg polymorphism was associated with a significantly decreased risk of OSA in European (homozygote comparison: OR = 0.35, 95% CI = 0.14-0.85, P = 0.02), but not for Asian population.

CONCLUSIONS

Our study suggested that leptin and LEPR polymorphisms had no association with OSA risk in all examined patients, whereas there was an association between Gln233Arg polymorphism and OSA risk in Europeans.

Biomarkers associated with obstructive sleep apnea and morbidities: a scoping review

OBJECTIVE

To map potential biomarkers of obstructive sleep apnea (OSA)-associated morbidities in both adults and children, to identify gaps in current evidence, and to determine the value of conducting a full systematic review.

METHODS

A scoping review was undertaken of studies in patients with OSA that evaluated the potential value of biological markers in identifying OSA-associated morbidities. Retained articles were only those studies whose main objective was to identify morbidity biomarkers in subjects with OSA, the latter being confirmed with a full overnight polysomnography (PSG) in a laboratory or at-home settings. The methodology of the selected studies was classified using an adaptation of the evidence quality criteria recommended by the American Academy of Pediatrics. Additionally the biomarkers were categorized according to their potential clinical applicability.

RESULTS

572 citations were identified of which 48 met inclusion criteria. Thirty-four studies were conducted in adults and 14 involved children. Most of the studies evaluated blood biomarkers, and presented 31 potential diagnostic biomarkers.

CONCLUSION

The majority of studies that performed explored blood-based biomarkers, with most not identifying definitive morbidity biomarkers. Of the potentially promising morbidity biomarkers, plasma IL-6 and high sensitivity C-reactive protein appear to exhibit a favorable profile, and may discriminate OSA patients with and without morbidities in both adults and children. MRP 8/14 was retained in children as well as cardiovascular morbidity-associated biomarker. Urinary neurotransmitters may also provide a good tool for screening OSA cognitive morbidity in children.

Diagnostic capability of biological markers in assessment of obstructive sleep apnea: a systematic review and meta-analysis

OBJECTIVE

The purpose of this systematic review is to evaluate the diagnostic value of biological markers (exhaled breath condensate, blood, salivary and urinary) in the diagnosis of OSA in comparison to the gold standard of nocturnal PSG.

METHODS

Studies that differentiated OSA from controls based on PSG results, without age restriction, were eligible for inclusion. The sample of selected studies could include studies in obese patients and with known cardiac disease. A detailed individual search strategy for each of the following bibliographic databases was developed: Cochrane, EMBASE, MEDLINE, PubMed, and LILACS. The references cited in these articles were also crosschecked and a partial grey literature search was undertaken using Google Scholar. The methodology of selected studies was evaluated using the 14-item Quality Assessment Tool for Diagnostic Accuracy Studies.

RESULTS

After a two-step selection process, nine articles were identified and subjected to qualitative and quantitative analyses. Among them, only one study conducted in children and one in adults found biomarkers that exhibit sufficiently satisfactory diagnostic accuracy that enables application as a diagnostic method for OSA.

CONCLUSION

Kallikrein-1, uromodulin, urocotin-3, and orosomucoid-1 when combined have enough accuracy to be an OSA diagnostic test in children. IL-6 and IL-10 plasma levels have potential to be good biomarkers in identifying or excluding the presence of OSA in adults.

Obstructive sleep apnea risk and psychological health among non-Hispanic blacks in the Metabolic Syndrome Outcome (MetSO) cohort study

INTRODUCTION

This study assessed associations of depression and anxiety with risk of obstructive sleep apnea (OSA) among non-Hispanic blacks in the Metabolic Syndrome Outcome (MetSO) study.

METHOD

A total of 1,035 patients participated. ARES™ score ≥6 defined high OSA risk. Moderate depression was defined by a CES-D score ≥16. Moderate anxiety was measured by a BAI score ≥16.

RESULTS

The mean age was 62 ± 14 years; 70% were female. A total of 93% were diagnosed with hypertension; 61%, diabetes; and 72%, dyslipidemia; 90% were overweight/obese; 33% had a history of heart disease; and 10% had a stroke. Logistic regression analysis, adjusting for age and gender, showed that patients with depression had nearly two-fold increased odds of being at risk for OSA (OR 1.75, 95% CI 1.02-2.98, p < 0.05). Patients with anxiety had three-fold increased odds of being at risk for OSA (OR 3.30, 95% CI 2.11-5.15, p < 0.01). After adjusting for marital status and income, patients with anxiety had a 6% increase in OSA risk (OR 1.06, 95% CI 1.04-1.09, p < 0.05), but depression was no longer significant.

CONCLUSION

Our results suggest that non-Hispanic blacks with metabolic syndrome who experience anxiety and/or depression should be screened for OSA.

Nonapnea sleep disorders and incident chronic kidney disease: a population-based retrospective cohort study

Nonapnea sleep disorders (NASDs) are associated with an increased risk of stroke, diabetes, and hypertension. No longitudinal study has yet examined the association between NASD and chronic kidney disease (CKD) by using epidemiologic study methods. To test this hypothesis, we examined the effect of NASD on the incidence of CKD in a large population-based retrospective cohort study. Based on a retrospective cohort study of a general population sample of 128 to 436 patients in the Taiwan National Health Insurance Research Database from January 1, 1998 to December 31, 2001, 42 to 812 NASD patients were followed up for 10.2 ± 3.12 years, and additional 85 to 624 individuals had no NASD at baseline. The International Classification of Diseases, Ninth Revision, Clinical Modification was used to identify the diagnosis of disease. Cox proportional hazard regression models were used to assess the association between NASD and subsequent CKD risk. The incidence rate of CKD was significantly higher in the NASD cohort than in the comparison cohort (2.68 vs 1.88 per 1000 person-years, respectively). After we adjusted for age, sex, and comorbidities, the risk of developing CKD was significant for patients with NASD (adjusted hazard ratio [HR] = 1.13; 95% confidence interval [CI] = 1.05-1.22; P < 0.01). Among different types of NASDs, patients with sleep disturbance associated disorders had a 14% increased risk of developing CKD (95% CI = 1.03-1.26; P < 0.01), whereas patients with insomnia had a 13% increased risk of subsequent CKD (95% CI = 1.02-1.25; P < 0.05) compared with the non-NASD cohort. Kaplan-Meier survival analysis indicated that the CKD-free rate was 1% lower in the NASD cohort than in the comparison cohort (log-rank test, P < 0.0001). Our study provides evidence that patients with NASD have an increased risk of developing subsequent CKD compared with patients without NASD; men, elderly people, and patients with concomitant comorbidities are at the greatest risk.

Sclerostin in Obstructive Sleep Apnea

Sclerostin, a glycoprotein involved in vascular calcification, could play a role in cardiovascular disorders. Obstructive sleep apnea (OSA) is frequently associated with cardiovascular comorbidities. Thus, in this study we set out to assess the level of sclerostin in patients with OSA. Sclerostin was evaluated in the serum by ELISA method in 106 patients (43 women) with OSA of the mean age of 55 ± 10 years, BMI of 33.1 ± 7.9 kg/m(2), and apnea/hypopnea index (AHI) of 29.7 ± 18.9. There were 76 (72 %) patients with cardiovascular comorbidities in the OSA group. The results were compared with those in 49 healthy control subjects. We found that the level of sclerostin was higher in the female OSA patients than that in female controls (80.1 ± 36.5 pg/ml vs. 61.4 ± 24.1 pg/ml; p < 0.05) and it correlated with AHI (rs = 0.32, p < 0.01) and desaturation index (rs = 0.34, p < 0.01). Further, in OSA women with cardiovascular comorbidities, sclerostin was higher than in women without such comorbidities (87.0 ± 37.4 pg/ml vs. 57.3 ± 22.1 pg/ml; p < 0.05). In men, there were no differences in the serum sclerostin level between the OSA and control subjects, nor was there any relationship with cardiovascular diseases. In conclusion, increased serum sclerostin coincides with the severity of OSA and its cardiovascular sequelae in female patients.

Effect of preoperative continuous positive airway pressure duration on outcomes after maxillofacial surgery for obstructive sleep apnoea

Continuous positive airway pressure (CPAP) remains the first-line treatment for obstructive sleep apnoea (OSA), and is known to result in various physiological changes. The objective of this study was to evaluate the association between duration of preoperative CPAP therapy and outcome after maxillomandibular advancement (MMA) for OSA. We retrospectively analysed consecutive patients treated at our institution, and divided them into 2 groups based on duration of treatment with CPAP: short-term (up to 12 months) and long-term use (12 months or more). We controlled for baseline demographic and clinical characteristics. We compared postoperative scores for the apnoea/hypopnoea index (AHI) and the Epworth sleepiness scale (ESS), and lowest recorded oxygen saturation between groups. In 43 patients data were available on the preoperative use of CPAP, and in 37 of them preoperative and postoperative polysomnographic data were also available for inclusion. Most had bimaxillary advancement with genioplasty. Differences between the groups in mean reduction in the AHI and lowest oxygen saturation were not significant, and operative success rates were comparable. After operation, the reduction in ESS scores was significantly greater in the long-term group than in the short-term group (mean (SD) 8(3) compared with 2 (2), respectively, p<0.001). Our results suggest that the duration of use of CPAP preoperatively does not significantly influence objective outcome measures. The reduction in AHI scores after MMA was equivalent in both groups. The long-term group seemed to fare better than the short-term group on subjective outcome measures.

Lipid profile after long-term APAP in OSA patients

PURPOSE

This study aimed to explore the impact of an 8-year therapy with autoadjusting positive airway pressure (APAP) on fasting lipid level in a sample of Portuguese moderate/severe obstructive sleep apnea (OSA) patients. Besides contributing to the comprehension of the complex relationship between dyslipidemia and OSA, it provided new data regarding the effectiveness of a long term APAP treatment.

METHODS

Thirty-nine male patients with moderate to severe OSA were included in the study. APAP was prescribed to all patients. Fifteen patients were under lipid-lowering medication throughout the study, and another 15 patients never used lipid-lowering medication at any time during the study. Fasting morning venous blood samples were collected at three time points (baseline 6 months and 8 years) and lipids were estimated. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) 21.0 software.

RESULTS

After 8 years of APAP treatment, patients presented a similar body mass index but a significantly less severe daytime sleepiness. Patients on lipid-lowering medication exhibited a higher reduction in total cholesterol than those naïf from that medication, but the reduction was not statistically significant after adjusting for medication and APAP adherence.

CONCLUSIONS

Long-term APAP treatment improves OSA but does not seem to contribute to changes in fasting lipids.

[Beneficial effect of continuous positive airway pressure therapy in obstructive sleep apnea syndrome]

Continuous positive airway pressure therapy is an evidence based therapy of obstructive sleep apnea syndrome. The effective treatment of obstructive sleep apnea can decrease sympaticotonia and, consequently, blood pressure. Furthermore, it can improve inflammatory and metabolic parameters resulting in a decreased cardiovascular risk. This article summarizes the positive effects of continuous positive airway pressure therapy on cardiovascular risk factors in obstructive sleep apnea syndrome.