Obesity and obstructive sleep apnea: pathogenic mechanisms and therapeutic approaches

Prevalence of sleep disorders among medical students and their association with poor academic performance: A cross-sectional study

BACKGROUND

Sleep quality is of paramount importance for human health. This multi-site study measures the proportion and types of self-reported sleep disorders in medical students and evaluates their association with academic performance by Grade Point Average (GPA).

MATERIALS AND METHODS

A cross-sectional survey was conducted on medical students from two medical schools in Jordan during the 2018/2019 academic year. The study utilized the SLEEP-50 questionnaire to estimate the proportion of several sleep disorders and their effects on daily functioning. Below average GPAs were considered poor academic performance.

RESULTS

1041 medical students' online surveys were analyzed from two medical schools' campuses, representing a 29.7% response rate. Their mean age was 22 ± 2.1 years (ranging from 18 to 37) and 52.6% were female. The mean body mass index was 24.2 ± 4.4 kg/m2. According to the SLEEP-50 questionnaire, the prevalence of sleep disorders among studied medical students ranged from 0.6% for sleep state misperception (SSM) to 23.1% for hypersomnia. Using binary logistic regression, after adjusting for gender and obesity, poor academic performance was associated with a risk for insomnia [adjusted odds ratio (OR) = 1.96, p < 0.001]; affective disorder [OR = 2.24, P < 0.001]; SSM [OR = 6.40, p = 0.045]; narcolepsy [OR = 9.54, p = 0.045]; and circadian rhythm disorders [OR = 2.03, p < 0.001].

CONCLUSION

Sleep disorders are common among medical students. Several sleepdisorders were associated with poor academic performance. Proper diagnosis and treatment of sleep disorders may remedy this issue.

Association of estimated sleep duration and naps with mortality and cardiovascular events: a study of 116 632 people from 21 countries

AIMS

To investigate the association of estimated total daily sleep duration and daytime nap duration with deaths and major cardiovascular events.

METHODS AND RESULTS

We estimated the durations of total daily sleep and daytime naps based on the amount of time in bed and self-reported napping time and examined the associations between them and the composite outcome of deaths and major cardiovascular events in 116 632 participants from seven regions. After a median follow-up of 7.8 years, we recorded 4381 deaths and 4365 major cardiovascular events. It showed both shorter (≤6 h/day) and longer (>8 h/day) estimated total sleep durations were associated with an increased risk of the composite outcome when adjusted for age and sex. After adjustment for demographic characteristics, lifestyle behaviours and health status, a J-shaped association was observed. Compared with sleeping 6-8 h/day, those who slept ≤6 h/day had a non-significant trend for increased risk of the composite outcome [hazard ratio (HR), 1.09; 95% confidence interval, 0.99-1.20]. As estimated sleep duration increased, we also noticed a significant trend for a greater risk of the composite outcome [HR of 1.05 (0.99-1.12), 1.17 (1.09-1.25), and 1.41 (1.30-1.53) for 8-9 h/day, 9-10 h/day, and >10 h/day, Ptrend < 0.0001, respectively]. The results were similar for each of all-cause mortality and major cardiovascular events. Daytime nap duration was associated with an increased risk of the composite events in those with over 6 h of nocturnal sleep duration, but not in shorter nocturnal sleepers (≤6 h).

CONCLUSION

Estimated total sleep duration of 6-8 h per day is associated with the lowest risk of deaths and major cardiovascular events. Daytime napping is associated with increased risks of major cardiovascular events and deaths in those with >6 h of nighttime sleep but not in those sleeping ≤6 h/night.

Effect of a Graduated Walking Program on the Severity of Obstructive Sleep Apnea Syndrome. A Randomized Clinical Trial

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is a common disease. The objective of this research was to determine the effectiveness of a graduated walking program in reducing the apnea-hypopnea index number in patients with obstructive sleep apnea syndrome (OSAS).

METHODS

A randomized controlled clinical trial with a two-arm parallel in three tertiary hospitals was carried out with seventy sedentary patients with moderate to severe OSAS. Twenty-nine subjects in each arm were analyzed by protocol. The control group received usual care, while usual care and an exercise program based on progressive walks without direct supervision for 6 months were offered to the intervention group.

RESULTS

The apnea-hypopnea index decreased by six points in the intervention group, and improvements in oxygen desaturation index, total cholesterol, and Low-Density Lipoprotein of Cholesterol (LDL-c) were observed. A higher decrease in sleep apnea-hypopnea index (45 ± 20.6 vs. 34 ± 26.3/h; p = 0.002) was found in patients with severe vs. moderate OSAS, as well as in oxygen desaturation index from baseline values (43.3 vs. 34.3/h; p = 0.046). Besides, High-Density Lipoprotein of Cholesterol (HDL-c) values showed a higher increase in the intervention group (45.3 vs. 49.5 mg/dL; p = 0.009) and also, a higher decrease in LDL-c was found in this group (141.2 vs. 127.5 mg/dL; p = 0.038).

CONCLUSION

A home physical exercise program is a useful and viable therapeutic measure for the management of OSAS.

Impact of sleep apnoea-hypopnoea syndrome on diabetic neuropathy. A systematic review

INTRODUCTION

Diabetes mellitus and sleep apnoea-hypopnoea syndrome appear to be related, but it is not well defined whether there is an increased risk of peripheral neuropathy in patients with both diseases. For this reason, we conducted a systematic review.

METHODS

Bibliographic search in 3 electronic databases using a predefined strategy and the PRISMA methodology. Only original studies (any type of design) published from 2000 onwards in English, French, Portuguese or Spanish were included. A study quality scale was established.

RESULTS

Twelve articles were selected, of which six studied type 2 diabetic patients. The overall prevalence of sleep apnoea-hypopnoea syndrome was 43.7% (1,559/3,564 patients). Diabetic neuropathy was more frequent in patients with sleep apnoea-hypopnoea syndrome in nine studies, although significantly only in four (60% vs 27%, P<.001; 64.5% vs 36%, P=.03; 37% vs 23.4%, P<.02; 66.6% vs 0%, P=.007). In one study, diabetic neuropathy was more frequent in patients without sleep apnoea-hypopnoea syndrome (although not statistically significant) and in 2 no comparison was made between patients with/without sleep apnoea/hypopnoea syndrome.

CONCLUSIONS

The observed results suggest a relationship between diabetes mellitus and sleep apnoea-hypopnoea syndrome in the occurrence of diabetic neuropathy.

Multimorbidity and Critical Care Neurosurgery: Minimizing Major Perioperative Cardiopulmonary Complications

With increasing prevalence of chronic diseases, multimorbid patients have become commonplace in the neurosurgical intensive care unit (neuro-ICU), offering unique management challenges. By reducing physiological reserve and interacting with one another, chronic comorbidities pose a greatly enhanced risk of major postoperative medical complications, especially cardiopulmonary complications, which ultimately exert a negative impact on neurosurgical outcomes. These premises underscore the importance of perioperative optimization, in turn requiring a thorough preoperative risk stratification, a basic understanding of a multimorbid patient’s deranged physiology and a proper appreciation of the potential of surgery, anesthesia and neurocritical care interventions to exacerbate comorbid pathophysiologies. This knowledge enables neurosurgeons, neuroanesthesiologists and neurointensivists to function with a heightened level of vigilance in the care of these high-risk patients and can inform the perioperative neuro-ICU management with individualized strategies able to minimize the risk of untoward outcomes. This review highlights potential pitfalls in the intra- and postoperative neuro-ICU period, describes common preoperative risk stratification tools and discusses tailored perioperative ICU management strategies in multimorbid neurosurgical patients, with a special focus on approaches geared toward the minimization of postoperative cardiopulmonary complications and unplanned reintubation.

Sleep disturbances: one of the culprits of obesity-related cardiovascular risk?

Growing evidence suggested that Sleep Disorders (SD) could increase the risk of developing obesity and could contribute to worsen obesity-related cardiovascular risk. Further, obesity per se has been reported to blunt sleep homeostasis. This happens through several mechanisms. First of all, the excessive adipose tissue at neck and chest levels could represent a mechanical obstacle to breathe. Moreover, the visceral adipose tissue is known to release cytokines contributing to low-grade chronic inflammation that could impair the circadian rhythm. Also, nutrition plays an important role in sleep homeostasis. High fat and/or high carbohydrate diets are known to have a negative impact on both sleep quality and duration. In addition, obesity predisposes to a condition called "obstructive sleep apnea" that has a detrimental effect on sleep. SD could increase the risk and/or could contribute to worsen cardiovascular risk usually associated with obesity. The chronic low grade inflammation associated with obesity has been reported to increase the risk of developing hypertension, type 2 diabetes and dyslipidemia. In turn, improving quality of sleep has been reported to improve the management of these cardiovascular risk factors. Thus, the aim of this manuscript is to provide evidence on the association of obesity and SD and on how they could contribute to the risk of developing cardiovascular risk factors such as hypertension, dyslipidemia and type 2 diabetes in obesity.

Carotid Body and Metabolic Syndrome: Mechanisms and Potential Therapeutic Targets

The carotid body (CB) is responsible for the peripheral chemoreflex by sensing blood gases and pH. The CB also appears to act as a peripheral sensor of metabolites and hormones, regulating the metabolism. CB malfunction induces aberrant chemosensory responses that culminate in the tonic overactivation of the sympathetic nervous system. The sympatho-excitation evoked by CB may contribute to the pathogenesis of metabolic syndrome, inducing systemic hypertension, insulin resistance and sleep-disordered breathing. Several molecular pathways are involved in the modulation of CB activity, and their pharmacological manipulation may lead to overall benefits for cardiometabolic diseases. In this review, we will discuss the role of the CB in the regulation of metabolism and in the pathogenesis of the metabolic dysfunction induced by CB overactivity. We will also explore the potential pharmacological targets in the CB for the treatment of metabolic syndrome.

Association of the serum irisin level with obstructive sleep apnea: a body mass index- and physical activity-matched study

Obesity is strongly correlated with the pathogenesis of obstructive sleep apnea (OSA); myokines may play important roles in this condition. We performed a body mass index- (BMI) and physical activity- (PA) matched study to explore the relationship between the irisin level and OSA. Ninety-six consecutive participants were recruited. After matching in terms of BMI and PA, 28 OSA patients and 28 healthy controls were finally included. Whole-night laboratory-based polysomnography was used to identify OSA. The Recent Physical Activity Questionnaire and Epworth Sleepiness Scale Questionnaire were employed to assess PA over the past 4 weeks, and daytime sleepiness. We measured serum irisin, fasting blood glucose, and insulin levels in blood samples. The serum irisin concentrations differed significantly between the control, mild OSA, moderate OSA, and severe OSA groups (p < 0.001) and correlated significantly with the apnea/hypopnea index (AHI) (r = -0.787, p < 0.001). All of age, BMI, neck, waist and hip circumferences, fasting blood glucose level, and the Epworth Sleepiness Scale and PA scores were associated with irisin levels (p < 0.05). After adjustment for these factors, the serum irisin level was independently correlated with the AHI (r = -0.428, p = 0.002). On forward logistic regression analysis, the association remained significant in the final multiple regression model (β = -0.107, p < 0.001). The serum irisin concentration was significantly correlated with OSA severity, independently of BMI and PA. Further studies are needed to determine the molecular mechanisms in play.

Genetic Underpinnings of Increased BMI and Its Association With Late Midlife Cognitive Abilities

Objectives: First, we test for differences in various cognitive abilities across trajectories of body mass index (BMI) over the later life course. Second, we examine whether genetic risk factors for unhealthy BMIs—assessed via polygenic risk scores (PRS)—predict cognitive abilities in late-life. Methods: The study used a longitudinal sample of Vietnam veteran males to explore the associations between BMI trajectories, measured across four time points, and later cognitive abilities. The sample of 977 individuals was drawn from the Vietnam Era Twin Study of Aging. Cognitive abilities evaluated included executive function, abstract reasoning, episodic memory, processing speed, verbal fluency, and visual spatial ability. Multilevel linear regression models were used to estimate the associations between BMI trajectories and cognitive abilities. Then, BMI PRS was added to the models to evaluate polygenic associations with cognitive abilities. Results: There were no significant differences in cognitive ability between any of the BMI trajectory groups. There was a significant inverse relationship between BMI-PRS and several cognitive ability measures. Discussion: While no associations emerged for BMI trajectories and cognitive abilities at the phenotypic levels, BMI PRS measures did correlate with key cognitive domains. Our results suggest possible polygenic linkages cutting across key components of the central and peripheral nervous system.

MRI evaluation of cerebrovascular reactivity in obstructive sleep apnea

Obstructive sleep apnea (OSA) is characterized by intermittent obstruction of the airways during sleep. Cerebrovascular reactivity (CVR) is an index of cerebral vessels' ability to respond to a vasoactive stimulus, such as increased CO₂. We hypothesized that OSA alters CVR, expressed as a breath-hold index (BHI) defined as the rate of change in CBF or BOLD signal during a controlled breath-hold stimulus mimicking spontaneous apneas by being both hypercapnic and hypoxic. In 37 OSA and 23 matched non sleep apnea (NSA) subjects, we obtained high temporal resolution CBF and BOLD MRI data before, during, and between five consecutive BH stimuli of 24 s, each averaged to yield a single BHI value. Greater BHI was observed in OSA relative to NSA as derived from whole-brain CBF (78.6 ± 29.6 vs. 60.0 ± 20.0 mL/min²/100 g, P = 0.010) as well as from flow velocity in the superior sagittal sinus (0.48 ± 0.18 vs. 0.36 ± 0.10 cm/s², P = 0.014). Similarly, BOLD-based BHI was greater in OSA in whole brain (0.19 ± 0.08 vs. 0.15 ± 0.03%/s, P = 0.009), gray matter (0.22 ± 0.09 vs. 0.17 ± 0.03%/s, P = 0.011), and white matter (0.14 ± 0.06 vs. 0.10 ± 0.02%/s, P = 0.010). The greater CVR is not currently understood but may represent a compensatory mechanism of the brain to maintain oxygen supply during intermittent apneas.

Global burden of sleep-disordered breathing and its implications

One-seventh of the world's adult population, or approximately one billion people, are estimated to have OSA. Over the past four decades, obesity, the main risk factor for OSA, has risen in striking proportion worldwide. In the past 5 years, the WHO estimates global obesity to affect almost two billion adults. A second major risk factor for OSA is advanced age. As the prevalence of the ageing population and obesity increases, the vulnerability towards having OSA increases. In addition to these traditional OSA risk factors, studies of the global population reveal select contributing features and phenotypes, including extreme phenotypes and symptom clusters that deserve further examination. Untreated OSA is associated with significant comorbidities and mortality. These represent a tremendous threat to the individual and global health. Beyond the personal toll, the economic costs of OSA are far-reaching, affecting the individual, family and society directly and indirectly, in terms of productivity and public safety. A better understanding of the pathophysiology, individual and ethnic similarities and differences is needed to better facilitate management of this chronic disease. In some countries, measures of the OSA disease burden are sparse. As the global burden of OSA and its associated comorbidities are projected to further increase, the infrastructure to diagnose and manage OSA will need to adapt. The use of novel approaches (electronic health records and artificial intelligence) to stratify risk, diagnose and affect treatment are necessary. Together, a unified multi-disciplinary, multi-organizational, global approach will be needed to manage this disease.

Five-year relative survival in sleep apnea patients with a subsequent cancer diagnosis

STUDY OBJECTIVES

In vitro and animal studies suggest that intermittent hypoxia characterizing sleep apnea contributes to accelerated cancer progression. However, the impact of sleep apnea on survival subsequent to cancer diagnosis is unknown.

METHODS

We identified a cohort of 1,575 adults diagnosed with sleep apnea between 2005 and 2014 with a subsequent cancer diagnosis via linkage of the University of Washington Medicine system and a population-based cancer registry serving the same Seattle-Puget Sound region. We computed age-standardized 5-year relative survival after cancer diagnosis for all cancers combined, and for specific cancer sites, for both the sleep apnea cohort and the general Seattle-Puget Sound population, and we used US life tables as the reference population. Relative survival was estimated by sex, cancer stage, and health care engagement.

RESULTS

Five-year overall relative survival for cancer was more favorable in the sleep apnea cohort than in the general population [83.6%, 95% confidence interval (CI): 79.8%-86.8% vs 71.6%, 95% CI: 71.3%-71.9%]; this pattern was applicable to most specific cancer sites. However, 5-year relative survival was slightly less favorable in the sleep apnea cohort among patients with melanoma (97.7%, 95% CI: 84.6%-99.7% vs 99.2%, 95% CI: 98.8%-99.5%) and cancer of the corpus uteri (84.0%, 95% CI: 58.2%-94.5% vs 84.6%, 95% CI: 83.1%-86.0%).

CONCLUSIONS

The fact that survival after cancer, overall and for most cancer sites, was more favorable in patients with sleep apnea warrants larger community-based studies to further tease out effects of sleep apnea and treatment on site-specific survival for different cancer types, particularly in patients with melanoma or uterine cancer.

Abdominal Obesity Is More Strongly Correlated with Obstructive Sleep Apnea than General Obesity in China: Results from Two Separated Observational and Longitudinal Studies

BACKGROUND

Previous studies have reported that obesity can result in or worsen obstructive sleep apnea (OSA). However, whether abdominal or general obesity indices or visceral adiposity indicators have a stronger association with OSA remains unclear.

METHODS

This cross-sectional study included 4344 patients who underwent polysomnography (PSG) due to suspicion of OSA. We also performed a longitudinal study on 86 patients who underwent bariatric surgery to confirm the relationship between OSA and obesity. Data on overnight PSG parameters, biochemical biomarkers, and multiple anthropometric obesity indices were collected.

RESULTS

In the cross-sectional study, waist circumference (WC) and body mass index (BMI) were independently associated with the apnea-hypopnea index (AHI) after adjusting for potential confounding factors (additional R² = 0.232, standardized beta coefficient [Beta] = 0.210; and additional R² = 0.015, Beta = 0.183, respectively). Logistic regression analysis showed similar results, as did stratified analysis of adult males aged ≤ 55 years. Restricted cubic spline (RCS) analysis revealed a linear dose-response relationship between OSA and obesity. In the longitudinal study, no significant relationship was found between remission of OSA and improvement in WC and BMI (r = 0.252, p = 0.098; and r = 0.132, p = 0.395, respectively), whereas the change in the visceral adiposity indicator (lipid accumulation calculated according to WC and fasting triglycerides) was significantly correlated with ΔAHI (r = 0.322, p = 0.033).

CONCLUSIONS

Abdominal obesity, rather than general obesity, appears to play a more important role in OSA.

The association between obesity indices and obstructive sleep apnea is modified by age in a sex-specific manner

BACKGROUND

The beneficial effects of weight reduction on obstructive sleep apnea (OSA) are highly variable. Whether or not the variability is associated with the effects of age and sex remains unclear. This study examined this issue with large cross-sectional data.

METHOD

Anthropometric measurements, polysomnographic variables, biochemical indicators, and medical history were collected for each participant. Multivariable linear regression with interaction terms was used to estimate the modification effect of age on the associations between OSA severity (assessed by apnea-hypopnea index, AHI) with obesity indices (body mass index, BMI; neck circumference, NC; waist circumference, WC; waist-to-hip ratio, WHR) in a sex-specific manner, and vice versa. To facilitate interpretation of the results, participants were further classified into six subpopulations according to both sex and age, and population-specific beta-coefficients were calculated and compared.

RESULTS

A total of 5756 adults (4600 men) with suspected OSA were included in the study. BMI, NC, WC, and WHR were all positively correlated with AHI after adjusting for potential confounders in all populations. In men, these associations were much stronger and more significant in younger than older individuals (P for interaction < 0.001). For example, a 10% increase in BMI was independently associated with a 32% increase in AHI for men < 40 years old, whereas the corresponding increases were 21% and 17% for men 40-60 and > 60 years old, respectively. By contrast, no modification effect of age was observed in women (P for interaction > 0.05). A 10% increase in BMI was associated with 26%, 27%, and 24% increases in AHI for women < 40, 40-60, and > 60 years old, respectively.

CONCLUSIONS

Age modifies the associations between obesity indices and OSA severity in a sex-specific manner. These findings may broaden the understanding of age- and sex-related heterogeneities in the pathogenic role of obesity in OSA, and may be beneficial for individualized risk evaluation and treatment management for patients with OSA.

The immune-sleep crosstalk in inflammatory bowel disease

Sleep disorders are progressively common and sometimes are associated with aberrant regulation of the adaptive and innate immune responses. Sleep interruption can increase the inflammatory burden by enhancing the pro-inflammatory cytokines particularly in patients with chronic diseases such as inflammatory bowel disease (IBD). IBD is a chronic inflammatory disease characterized by immune dysregulation, dysbiosis of gut microbiome, and poor-quality life. Therefore, this review highlights the crosstalk between sleep and immune responses during the progression of IBD.

Effectiveness of an intensive weight-loss program for severe OSA in patients undergoing CPAP treatment: a randomized controlled trial

STUDY OBJECTIVES

To determine whether an intensive weight-loss program (IWLP) is effective for reducing weight, the severity of obstructive sleep apnea (OSA), and metabolic variables in patients with obesity and severe OSA undergoing continuous positive airway pressure treatment.

METHODS

Forty-two patients were randomized to the control (CG, n = 20) or the intervention group (IG, n = 22), who followed a 12-month IWLP. The primary outcome was a reduction in the apnea-hypopnea index (AHI) as measured at 3 and 12 months by full polysomnography. Metabolic variables, blood pressure, body fat composition by bioimpedance, carotid intima media thickness, and visceral fat by computed tomography were also assessed.

RESULTS

Mean age was 49 (6.7) years, body mass index 35 (2.7) kg/m², and AHI 69 (20) events/h. Weight reduction was higher for the IG than the CG at 3 and 12 months, -10.5 versus -2.3 kg (P < .001), and -8.2 versus -0.1 kg (P < .001), respectively, as was loss of visceral fat at 12 months. AHI decreased more in the IG at 3 months (-23.72 versus -9 events/h) but the difference was not significant at 12 months, though 28% of patients from the IG had an AHI < 30 events/h compared to none in the CG (P = .046). At 12 months, the IG showed a reduction in C-reactive protein (P = .013), glycated hemoglobin (P = .031) and an increase in high density lipoprotein cholesterol (P = .027).

CONCLUSIONS

An IWLP in patients with obesity and severe OSA is effective for reducing weight and OSA severity. It also results in an improvement in lipid profiles, glycemic control, and inflammatory markers.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Effectiveness of an Intensive Weight Loss Program for Obstructive Sleep Apnea Syndrome (OSAS) Treatment; Identifier: NCT02832414; URL: https://clinicaltrials.gov/ct2/show/record/NCT02832414.

The relationship between obstructive sleep apnea syndrome and obesity: A new perspective on the pathogenesis in terms of organ crosstalk

INTRODUCTION

Obstructive sleep apnea syndrome (OSAS) is a common disorder that has a major impact on public health. The connection between OSAS and obesity is very complex and likely represents an interaction between biological and lifestyle factors. Oxidative stress, inflammation and metabolic dysregulation are both actors involved in the pathogenesis of OSAS and obesity. Also, the current evidence suggests that gut microbiota plays a significant role in the emergence and progression of some metabolic disorders. When the relationship between OSAS and obesity is evaluated extensively, it is understood that they show mutual causality with each other, and that metabolic challenges such as impaired microbiota affect this bidirectional organ interaction, and by ensuing organ injury.

OBJECTIVES

The aim of this study is to investigate the association between OSAS and obesity, and the effect of "organ crosstalk" on the pathogenesis of the relationship and to contribute to the diagnosis and treatment options in the light of current data.

DATA SOURCE

We performed an electronic database search including PubMed, EMBASE and Web of Science. We used the following search terms: OSAS, obesity, inflammation, metabolic dysregulation and gut microbiota.

CONCLUSION

Obesity and OSAS adversely affect many organs and systems. Besides the factors affecting the diagnosis of the OSAS-obesity relationship, mutual organ interactions among the respiratory system, adipose tissue and intestines should not be ignored for prevention and treatment of OSAS and obesity. Comprehensive clinical trials addressing the efficacy and efficiency of current or potential treatments on therapeutic applications in the OSAS-obesity relationship are needed.

Obesity associated with increased postoperative pulmonary complications and mortality after trauma laparotomy

Background

Patient-related risk factors for the development of postoperative pulmonary complications (PPCs) include age ≥ 60-years, congestive heart failure, hypoalbuminemia and smoking. The effect of obesity is unclear and has not been shown to independently increase the likelihood of PPCs in trauma patients undergoing trauma laparotomy. We hypothesized the likelihood of mortality and PPCs would increase as body mass index (BMI) increases in trauma patients undergoing trauma laparotomy.

Methods

The Trauma Quality Improvement Program (2010–2016) was queried to identify trauma patients ≥ 18-years-old undergoing trauma laparotomy within 6-h of presentation. A multivariable logistic regression analysis was used to determine the likelihood of PPCs and mortality when stratified by BMI.

Results

From 8,330 patients, 2,810 (33.7%) were overweight (25–29.9 kg/m²), 1444 (17.3%) obese (30–34.9 kg/m²), 580 (7.0%) severely obese (35–39.9 kg/m²), and 401 (4.8%) morbidly obese (≥ 40 kg/m²). After adjusting for covariates including age, injury severity score, chronic obstructive pulmonary disease, smoking, and rib/lung injury, the likelihood of PPCs increased with increasing BMI: overweight (OR = 1.37, CI 1.07–1.74, p = 0.012), obese (OR = 1.44, CI 1.08–1.92, p = 0.014), severely obese (OR = 2.20, CI 1.55–3.14, p < 0.001), morbidly obese (OR = 2.42, CI 1.67–3.51, p < 0.001), compared to those with normal BMI. In addition, the adjusted likelihood of mortality increased for the morbidly obese (OR = 2.60, CI 1.78–3.80, p < 0.001) compared to those with normal BMI.

Conclusion

Obese trauma patients undergoing emergent trauma laparotomy have a high likelihood for both PPCs and mortality, with morbidly obese trauma patients having the highest likelihood for both. This suggests obesity should be accounted for in risk prediction models of trauma patients undergoing laparotomy.

Electronic supplementary material

The online version of this article (10.1007/s00068-020-01329-w) contains supplementary material, which is available to authorized users.

Association between objectively measured sleep duration, adiposity and weight loss history

BACKGROUND

An association between sleep and obesity has been suggested in several studies, but many previous studies relied on self-reported sleep and on BMI as the only adiposity measure. Moreover, a relationship between weight loss history and attained sleep duration has not been thoroughly explored.

DESIGN

The study comprised of 1202 participants of the European NoHoW trial who had achieved a weight loss of ≥5% and had a BMI of ≥25 kg/m² prior to losing weight. Information was available on objectively measured sleep duration (collected during 14 days), adiposity measures, weight loss history and covariates. Regression models were conducted with sleep duration as the explanatory variable and BMI, fat mass index (FMI), fat-free mass index (FFMI) and waist-hip ratio (WHR) as response variables. Analyses were conducted with 12-month weight loss, frequency of prior weight loss attempts or average duration of weight maintenance after prior weight loss attempts as predictors of measured sleep duration.

RESULTS

After adjusting for physical activity, perceived stress, smoking, alcohol consumption, education, sex and age, sleep duration was associated to BMI (P < 0.001), with the highest BMI observed in the group of participants sleeping <6 h a day [34.0 kg/m² (95% CI: 31.8-36.1)]. Less difference in BMI was detected between the remaining groups, with the lowest BMI observed among participants sleeping 8-<9 h a day [29.4 kg/m² (95% CI: 28.8-29.9)]. Similar results were found for FMI (P = 0.008) and FFMI (P < 0.001). We found no association between sleep duration and WHR. Likewise, we found no associations between weight loss history and attained sleep duration.

CONCLUSION

In an overweight population who had achieved a clinically significant weight loss, short sleep duration was associated with higher BMI, with similar associations for fat and lean mass. We found no evidence of association between weight loss history and attained sleep duration.

Bidirectional relationship between sleep and Alzheimer's disease: role of amyloid, tau, and other factors

As we age, we experience changes in our nighttime sleep and daytime wakefulness. Individuals afflicted with Alzheimer's disease (AD) can develop sleep problems even before memory and other cognitive deficits are reported. As the disease progresses and cognitive changes ensue, sleep disturbances become even more debilitating. Thus, it is imperative to gain a better understanding of the relationship between sleep and AD pathogenesis. We postulate a bidirectional relationship between sleep and the neuropathological hallmarks of AD; in particular, the accumulation of amyloid-β (Aβ) and tau. Our research group has shown that extracellular levels of both Aβ and tau fluctuate during the normal sleep-wake cycle. Disturbed sleep and increased wakefulness acutely lead to increased Aβ production and decreased Aβ clearance, whereas Aβ aggregation and deposition is enhanced by chronic increased wakefulness in animal models. Once Aβ accumulates, there is evidence in both mice and humans that this results in disturbed sleep. New findings from our group reveal that acute sleep deprivation increases levels of tau in mouse brain interstitial fluid (ISF) and human cerebrospinal fluid (CSF) and chronic sleep deprivation accelerates the spread of tau protein aggregates in neural networks. Finally, recent evidence also suggests that accumulation of tau aggregates in the brain correlates with decreased nonrapid eye movement (NREM) sleep slow wave activity. In this review, we first provide a brief overview of the AD and sleep literature and then highlight recent advances in the understanding of the relationship between sleep and AD pathogenesis. Importantly, the effects of the bidirectional relationship between the sleep-wake cycle and tau have not been previously discussed in other reviews on this topic. Lastly, we provide possible directions for future studies on the role of sleep in AD.

[Obesity and asthma: Mechanisms and therapeutic options]

Asthma and obesity are both common conditions, which lead to a substantial public health burden. The obese-asthma phenotype is characterized by poor asthma control, impaired lung function and decreased efficacy of inhaled treatment. However, this phenotype is highly heterogeneous and involves numerous mechanisms, including systemic inflammation and adipokines. A role for microbiota modifications and genetics has been suggested. Obese-asthma patient management currently consists in weight loss and usual anti-asthmatic treatment. New therapeutic options are being evaluated.

Pharyngeal dysfunction associated with early and late onset sleep disordered breathing in children

OBJECTIVE

To compare the frequency and type of diagnoses associated with pharyngeal dysfunction (PD) in children presenting with early versus late onset sleep disordered breathing (SDB).

METHODS

This was a retrospective, cross-sectional study. A consecutive series of children ≤3 years old who underwent management for SDB were retrospectively identified from a prospectively kept surgical database. The early onset group was compared with two separate late onset (≥4years old) groups. Diagnoses associated with PD included gastroesophageal reflux disease (GERD), swallowing dysfunction, prematurity, asthma, and obesity. Distribution of PD diagnoses, airway lesions, syndromic conditions, pulse oximetry scores, and endoscopic pattern of airway obstruction were compared.

RESULTS

73 patients with early onset SDB were identified (51 boys, mean age 2.25 ± 0.64 years, range 1.75-3 years) and compared with two groups of later onset SDB consisting of 75 and 72 patients with mean ages of 7.58 ± 2.40 years and 8.04 ± 3.34 years respectively (range 4-16 years). The early onset SDB group had a higher prevalence of PD diagnoses compared to the later onset group with 35 of 73 patients being diagnosed compared to 41 of 147 children (p = 0.01). Early onset SDB patients were more likely to have GERD or swallowing dysfunction (p < 0.01) while later onset patients more commonly presented with associated asthma or obesity (p < 0.01). There was no statistically significant difference in airway lesions between groups.

CONCLUSION

Early-onset SDB is associated with conditions causing PD more often than later-onset SDB. Identifying these conditions and optimizing their management may impact outcomes in treating pediatric SDB.

Parapharyngeal fat pad area at the subglosso-supraglottic level is associated with corresponding lateral wall collapse and apnea-hypopnea index in patients with obstructive sleep apnea: a pilot study

The aim of this study was to assess associations between fat pad areas at various anatomic levels and the sites of lateral wall collapse and disease severity in adult patients with obstructive sleep apnea (OSA). Forty-one patients with OSA who prospectively underwent drug-induced sleep computed tomography were included. Areas of parapharyngeal fat pads and degrees of lateral wall collapse at three representative anatomic levels (nasopharynx, oropharynx, and subglosso-supraglottis), and apnea-hypopnea index (AHI) were measured. In the subglosso-supraglottic region, the parapharyngeal fat pad area in 17 (41%) patients with complete lateral wall collapse was significantly larger than that in 24 (59%) patients without complete collapse (median, 236.0 mm² vs 153.0 mm²; P = 0.02). In multivariate regression analysis, the parapharyngeal fat pad area at the subglosso-supraglottic level (β = 0.02; P = 0.01) and body mass index (β = 3.24; P = 0.01) were independently associated with AHI. Our preliminary results supported that parapharyngeal fat pads at the subglosso-supraglottic level may be involved in the development of lateral wall collapse and then determine the severity of OSA. Further studies are warranted to investigate the effect of reducing parapharyngeal fat pads in the treatment of OSA.

Upper airway surgery to rescue the "untitratable" patient with OSA and obesity

None

This is a case report of an 41-year-old male with obesity (body mass index 90 kg/m²), severe obstructive sleep apnea (OSA), and an apnea-hypopnea index of 90 events/h despite high bilevel positive airway pressure (BPAP). He presented to the PAP Alternatives Clinic and underwent tonsillectomy, expansion sphincter pharyngoplasty, and partial uvulectomy to improve positive airway pressure effectiveness. Postoperative BPAP retitration resolved the patient's OSA. The patient is currently using BPAP therapy at home with improvement in both objective and self-reported OSA outcomes.

Impact of Obesity and Obstructive Sleep Apnea in Lateral Skull Base Cerebrospinal Fluid Leak Repair

OBJECTIVE

To investigate the prevalence and impact of obstructive sleep apnea (OSA) and obesity in lateral skull base cerebrospinal fluid leak repair (LSBR) of various etiologies.

METHODS

Retrospective case review at a tertiary skull base center was conducted of consecutive adults undergoing LSBR via transmastoid, middle cranial fossa, or combined approach between 2013-2018. The following data were collected: demographics, comorbidities, radiology and intraoperative findings, and surgical outcomes including complications and need for revision surgery or shunt placement. Patients with incomplete data or leaks following skull base surgery, trauma or chronic ear disease were excluded.

RESULTS

Ninety-four patients (67.4% female, mean age 53.5 ± 12.9 years) underwent repair for spontaneous (sCSFL, 44%) and other etiology (nsCSFL) leaks. nsCSFL served as a comparison group consisting of leaks status-post lateral skull base surgery, temporal bone fractures, and chronic ear disease. Class III obesity (P = .02), OSA (P = .03), and imaging findings of empty sella (OR = 3.32, P = .02), and skull base thinning including contralateral tegmen thinning (31%, OR = 4.3, P = .02), arachnoid granulations (26%, OR = 4.35, P = .02), and superior canal dehiscence (15.8%, OR = 8.57, P = .04) were more common in sCSFL. Four patients (4.2%) required surgical revision for recurrence, and another four (4.2%) resolved with shunting. Evidence of elevated intracranial hypertension was present in nine patients with sCSF leaks and was predictive of need for revision or shunt procedures (P < .01).

CONCLUSION

Obesity, OSA, and imaging consistent with elevated intracranial pressures were more common among patients with sCSFL. Elevated intracranial pressure predicted outcomes following multilayer repair of spontaneous CSF leaks LEVEL OF EVIDENCE: 4 Laryngoscope, 130:2234-2240, 2020.

The Role of Animal Models in Developing Pharmacotherapy for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a highly prevalent disease characterized by recurrent closure of the upper airway during sleep. It has a complex pathophysiology involving four main phenotypes. An abnormal upper airway anatomy is the key factor that predisposes to sleep-related collapse of the pharynx, but it may not be sufficient for OSA development. Non-anatomical traits, including (1) a compromised neuromuscular response of the upper airway to obstruction, (2) an unstable respiratory control (high loop gain), and (3) a low arousal threshold, predict the development of OSA in association with anatomical abnormalities. Current therapies for OSA, such as continuous positive airway pressure (CPAP) and oral appliances, have poor adherence or variable efficacy among patients. The search for novel therapeutic approaches for OSA, including pharmacological agents, has been pursued over the past years. New insights into OSA pharmacotherapy have been provided by preclinical studies, which highlight the importance of appropriate use of animal models of OSA, their applicability, and limitations. In the present review, we discuss potential pharmacological targets for OSA discovered using animal models.

Prevalence of obstructive sleep apnea in patients with peripheral arterial diseases

Background

The presence of obstructive sleep apnea (OSA), a novel cardiovascular risk factor, contributes to the development of peripheral arterial diseases (PAD). There is a lack of data showing how often these diseases coexist.

Aims

The aim of the study was to determine the prevalence of OSA in the population of patients with PAD.

Methods

Patients previously qualified for the first revascularization due to PAD were included in the study. All patients underwent an overnight sleep study to detect OSA. Diagnosis of OSA was made when the apnea–hypopnea index (AHI) was ≥5 per hour.

Results

From 141 patients (60% men, age 69.6 ± 9.5 years), OSA was diagnosed in 68 patients (48%). OSA occurred in mild form (5 ≤ AHI < 15/h) in 39 cases (28%), in moderate form (15 ≤ AHI < 30/h) in 21 cases (15%), and in severe form (AHI ≥ 30/h) in 8 cases (6%). Patients without OSA had significantly lower body mass index (BMI; 26.9 ± 5.5 vs. 27.7 ± 5.3 kg/m², p = 0.01) and lower hip circumference (97.4 ± 11.7 vs. 98.7 ± 7.4, p = 0.04). There were no differences in the distribution of other investigated cardiovascular risk factors and diseases between these groups. There were no significant differences in OSA distribution or its severity between patients with lower extremity artery disease and carotid artery disease.

Conclusions

The prevalence of OSA in patients with PAD is very high, affecting nearly half of the studied population.

Regularized logistic regression for obstructive sleep apnea screening during wakefulness using daytime tracheal breathing sounds and anthropometric information

Obstructive sleep apnea (OSA) is a prevalent health problem. Developing a technology for quick OSA screening is momentous. In this study, we used regularized logistic regression to predict the OSA severity level of 199 individuals (116 males) with apnea/hypopnea index (AHI) ≥ 15 (moderate/severe OSA) and AHI < 5 (non-OSA) using their tracheal breathing sounds (TBS) recorded during daytime, while they were awake. The participants were guided to breathe through their nose, and then through their mouth at their deep breathing rate. The least absolute shrinkage and selection operator (LASSO) feature selection approach was used to select the discriminative features from the power spectra of the TBS and the anthropometric information. Using a five-fold cross-validation procedure, five different training sets and their corresponding blind-testing sets were formed. The average blind-testing classification accuracy over the five different folds was found to be 79.3% ± 6.1 with the sensitivity (specificity) of 82.2% ± 7.2% (75.8% ± 9.9%). The accuracy for the entire dataset was found to be 81.1% with sensitivity (specificity) of 84.4% (77.0%). The feature selection and classification procedures were intelligible and fast. The selected features were physiologically meaningful. Overall, the results show that TBS analysis can be used as a quick and reliable prediction of the presence and severity of OSA during wakefulness without a sleep study. Graphical abstract Wakefulness screening of obstructive sleep apnea using tracheal breathing sounds and anthropometric information by means of regularized logistic regression with the least absolute shrinkage and selection operator approach for feature selection and classification.

Sleep apnoea among Australian Aboriginal and non-Aboriginal patients in the Northern Territory of Australia—a comparative study

Australian Aboriginal and Torres Straight Islanders (ATSI) are noted to have a higher burden of chronic health conditions. However, there is a paucity of data on obstructive sleep apnoea (OSA) in this population. In this retrospective study, we evaluated the clinical and polysomnographic (PSG) characteristics of ATSI and non-ATSI adult patients who underwent diagnostic PSG between 2011 and 2015. There were a total of 3078 patients. Of the total, 403 (13%) were of ATSI origin. Among those of ATSI origin, 61% were male and 39% females, while among the non-ATSI cohort, 66% were males. The median age was 47.8 years in ATSI and 51.5 years in the non-ATSI cohort. In the combined cohort, body mass index was more than 30 kg/m2 (61%), hypertension (14.4%), diabetes (17.8%), and heart disease (23.3%). The ATSI patients had higher rates of class III obesity (27 vs. 15%), hypertension (26 vs. 14%), cardiac disease (34 vs. 23%), and diabetes (37 vs. 17%). Among all the study participants, the PSG confirmed 83.7% of the patients had an apnoea–hypopnea index (AHI) more than 5/h, mild (AHI 5–15/h) in 28.4%, moderate (AHI 15–30/h) in 22.3%, and severe (AHI &gt; 30/h) in 33.0%. Among the ATSI patients, 46% had severe OSA. The median total AHI value was higher in the ATSI population (25, interquartile range [IQR]: 11–58) compared to the non-ATSI (17, IQR: 7–36), and in rural/remote population (19, IQR: 8–42) compared to urban (17, IQR: 7–37). This trend was similar for NREM (non-rapid eye movement)-AHI and REM (rapid eye movement)-AHI scores, although statistically significant difference was found only with ATSI status. In the combined cohort the probability of (OR = 1.62, 95% CI: 1.32–2.00, p &lt; 0.001) of severe OSA was 62% higher in individual with hypertension, however, when stratified by ATSI status, the association was only significant in the non-ATSI population (OR = 1.53 95% CI: 1.21–1.94, p &lt; 0.001). The odds of severe AHI was also significantly associated with heart disease (1.37; 95% CI: 1.14,1.63, p &lt; 0.001), diabetes (1.74; 95% CI: 1.43,2.10; p &lt; 0.001) and smoking (1.28; 95% CI: 1.09,1.50, p = 0.0023) in the overall study cohort. In both ATSI and non-ATSI patients, body mass index, neck circumference, sleep efficiency, wake after sleep onset, and respiratory arousal index were significantly higher and independently associated with severe AHI.

Arrhythmogenic mechanisms of obstructive sleep apnea in heart failure patients

Heart failure (HF) affects 23 million people worldwide and results in 300000 annual deaths. It is associated with many comorbidities, such as obstructive sleep apnea (OSA), and risk factors for both conditions overlap. Eleven percent of HF patients have OSA and 7.7% of OSA patients have left ventricular ejection fraction <50% with arrhythmias being a significant comorbidity in HF and OSA patients. Forty percent of HF patients develop atrial fibrillation (AF) and 30%-50% of deaths from cardiac causes in HF patients are from sudden cardiac death. OSA is prevalent in 32%-49% of patients with AF and there is a dose-dependent relationship between OSA severity and resistance to anti-arrhythmic therapies. HF and OSA lead to various downstream arrhythmogenic mechanisms, including metabolic derangement, remodeling, inflammation, and autonomic imbalance. (1) Metabolic derangement and production of reactive oxidative species increase late Na+ currents, decrease outward K+ currents and downregulate connexin-43 and cell-cell coupling. (2) remodeling also features downregulated K+ currents in addition to decreased Na+/K+ ATPase currents, altered Ca2+ homeostasis, and increased density of If current. (3) Chronic inflammation leads to downregulation of both Nav1.5 channels and K+ channels, altered Ca2+ homeostasis and reduced cellular coupling from alterations of connexin expression. (4) Autonomic imbalance causes arrhythmias by evoking triggered activity through increased Ca2+ transients and reduction of excitation wavefront wavelength. Thus, consideration of these multiple pathophysiological pathways (1-4) will enable the development of novel therapeutic strategies that can be targeted against arrhythmias in the context of complex disease, such as the comorbidities of HF and OSA.

Resolution of Symptomatic Obstructive Sleep Apnea Not Impacted by Preoperative Body Mass Index, Choice of Operation Between Sleeve Gastrectomy and Roux-en-Y Gastric Bypass Surgery, or Severity

BACKGROUND

Obstructive sleep apnea (OSA) is a serious obesity-associated disorder that causes significant short- and long-term medical consequences.

OBJECTIVE

The objective of this study is to compare the 6-month and 1-year postoperative symptomatic OSA remission rates of patients undergoing bariatric surgery based on their preoperative body mass index (BMI) stratification, type of bariatric operation-sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB)-and OSA severity.

METHODS

We retrospectively analyzed 297 obese patients with a diagnosis of OSA who had undergone either SG or RYGB between 2011 and 2015.

RESULTS

The overall 6-month symptomatic OSA remission rate for patients (n = 255) was 74.5%. At 6 months, patients with a preoperative BMI of 30-34.9 kg/m² (class I), 35-39.9 kg/m² (class II), and 40+ kg/m² (class III) had 100, 70.0, and 75.0% (p = 0.2164) remission rates, respectively. The 6-month remission rates for SG and RYGB were 75.3 and 70.8% (p = 0.5165), respectively. The overall 1-year symptomatic OSA remission rate for patients (n = 162) was 87.1%. At 1 year, class I, II, and III patients had 100, 85.7, and 87.5% (p = 0.5740) remission rates, respectively. The 1-year remission rates for SG and RYGB were 89.2 and 81.2% (p = 0.2189), respectively. A sub-analysis (n = 69) based on preoperative OSA severity levels did not affect the remission outcome at either the 6-month (p = 0.3670) or 1-year (p = 0.3004) follow-up.

CONCLUSION

Most obese patients experience symptomatic remission of their OSA after bariatric surgery, regardless of their preoperative BMI, choice of operation, or OSA severity.

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

RATIONALE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Healthy Weight and Obesity Prevention: JACC Health Promotion Series

Overweight and obesity have reached epidemic levels in the United States and worldwide, and this has contributed to substantial cardiovascular and other health risks. However, controversy exists concerning the causes of obesity and effective modalities for its prevention and treatment. There is also controversy related to the concept of metabolically healthy obesity phenotype, the "obesity paradox," and on the importance of fitness to protect individuals who are overweight or obese from cardiovascular diseases. In this state-of-the-art review, the authors focus on "healthy weight" with the emphasis on the pathophysiologic effects of weight gain on the cardiovascular system; mechanistic/triggering factors; and the role of preventive actions through personal, education/environment, and societal/authoritative factors, as well as factors to provide guidance for caregivers of health promotion. Additionally, the authors briefly review metabolically healthy obesity, the obesity paradox, and issues beyond lifestyle consideration for weight loss with medications and bariatric surgery.

Prevalence of Rapid Eye Movement-related Obstructive Sleep Apnea in Adult Narcolepsy

Objective The association between narcolepsy and rapid eye movement (REM)-related obstructive sleep apnea (OSA) has not been reported. This study aimed to examine the prevalence of REM-related OSA in narcolepsy patients. Methods From January 2013 to April 2018, 141 adult patients were diagnosed with narcolepsy using nocturnal polysomnography and the multiple sleep latency test. The prevalence of REM-related OSA in narcolepsy patients was retrospectively reviewed. Three criteria were used to determine REM-related OSA: Definition #1, an overall apnea-hypopnea index (AHI) ≥5 and AHI during REM (AHIREM)/AHI during non-rapid eye movement (NREM) (AHINREM) ≥2; Definition #2, an overall AHI ≥5 and AHI_REM/AHI_NREM≥2 and AHI_NREM <15; and Definition #3, an overall AHI ≥5 and AHI_REM/AHI_NREM≥2 and AHI_NREM <8 plus an REM sleep duration >10.5 minutes. Results Of the 141 narcolepsy patients, 26 were diagnosed with narcolepsy with cataplexy (NA-CA) and 115 with narcolepsy without cataplexy (NA w/o CA). Seventeen patients with NA-CA and 39 with NA w/o CA had OSA. According to Definition #1, the prevalence of REM-related OSA was 47.1% and 41.0%, respectively, in OSA patients with NA-CA and NA w/o CA; according to Definition #2, the respective prevalence was 47.1% and 38.5%, while that according to Definition #3 was 41.2% and 25.6%. No significant differences were found in the prevalence of REM-related OSA for each definition. Conclusion A high prevalence of REM-related OSA was confirmed in adult narcolepsy patients with OSA. Compared to previous reports, we noted a high frequency of REM-related OSA satisfying the relatively strict Definition #3. These results might reflect the pathophysiological characteristics of narcolepsy.

Obstructive sleep apnea among HIV-infected men in the highly active antiretroviral therapy era: a nation-wide longitudinal cohort study in Taiwan, 2000-2011

OBJECTIVES

This study compared the incidence of obstructive sleep apnea (OSA) between HIV-infected and matched non-infected persons and aimed to determine the effect of highly active antiretroviral therapy (HAART) on the incidence of OSA among HIV-infected men.

METHODS

A population-based cohort design was conducted using the National Health Insurance Research Database (NHIRD), which contained 13,552 HIV-infected persons and 134,361 matched age-, sex-, and index year-controls. The incidence density rates (IRR) were calculated to estimate the OSA incidence both in the HIV group and matched controls. Cox proportional hazard models were applied to assess the HAART effect on the incidence of OSA among HIV-infected men.

RESULTS

The IRR of OSA was lower in the HIV group than in the matched controls (1.91 vs. 2.26 per 1000 person-years, respectively). The associated factors for OSA in HIV-infected men were higher monthly salary (adjusted hazard ratio [aHR], 1.97, p < 0.01), obesity (aHR, 3.99, p < 0.01), and chronic obstructive pulmonary disease (aHR, 2.02, p < 0.01). Continued HAART at least a half year was associated with less diagnosed OSA (AHR, 0.70, p = 0.03) in HIV-infected men.

CONCLUSIONS

HIV-infected persons had a lower rate of OSA diagnosis compared to the matched controls. Healthcare providers are needed to increase awareness in HIV-infected men with sleep disorders, especially for those with low social economic status, comorbidities, and non-continuous HAART use.

The association of OSAS and uvula: the role of MRI in this egg-chicken problem in OSAS

PURPOSE

Obstructive sleep apnea syndrome (OSAS) is a condition resulting from repetitive partial or complete upper airway obstruction, and its etiology remains uncertain. Polysomnography is the gold standard diagnostic test for OSAS. However, there are long wait times for this evaluation, so questionnaires or ancillary diagnostic methods are used to select appropriate patients. One of these is magnetic resonance imaging (MRI). The present study aimed to investigate the association between clinical features of OSAS and uvular changes on MRI.

MATERIALS AND METHODS

A total of 102 participants, 80 with OSAS and 22 controls, were included in the study. All participants underwent full-night polysomnography, MRI, and anthropometric measurements.

RESULTS

In comparisons of MRI measurements of the uvula, statistically significant differences in uvular length, thickness, and angle were observed between the OSAS and control groups. MRI measurement significantly associated with apnea-hypopnea index was uvular thickness. Evaluation of anthropometric and MRI measurements revealed statistically significant associations between waist circumference and uvular thickness, uvular width, and oropharyngeal space among the OSAS patients.

CONCLUSION

Thickened uvula on MRI is associated with the presence of OSAS, and its thickness is well correlated with the severity of the diseases. Thus, it may be a reliable indicator of OSAS and could be used as a supportive finding to identify patients suitable for referral for diagnostic polysomnography.

Accuracy of global and/or regional anthropometric measurements of adiposity in screening sleep apnea: the ELSA-Brasil cohort

OBJECTIVE

Adiposity is a well-established risk factor for obstructive sleep apnea (OSA) but the existence of a preferable anthropometric measurement is not established or whether the combination of measurements may improve the accuracy to detect OSA. This study aimed to compare the accuracies of body mass index (BMI), several surrogate markers of body fat (in isolation or combined) and validated questionnaires for screening OSA.

METHODS

A total of 2059 participants from the ELSA-Brasil study given anthropometric measurements using standard procedures and a home sleep study. OSA was defined by an apnea-hypopnea index ≥15 events/hour.

RESULTS

The frequency of OSA was 32.3%. Compared with the non-OSA group, all anthropometric measurements were higher in the OSA group. Age and gender-adjusted BMI afforded the highest accuracy to detect OSA [AUC = 0.760 (0.739-0.781)], followed by waist [AUC = 0.753 (0.732-0.775)] and neck [AUC = 0.733 (0.711-0.755)] circumferences, waist-to-hip ratio [AUC = 0.722 (0.699-0.745)] and body shape index [AUC = 0.680 (0.656-0.704)]. The combination of two or more anthropometric measurements did not improve the accuracy of BMI in predicting OSA. The adjusted BMI had similar predictive performance to the NoSAS score [AUC = 0.748 (0.727-0.770)] but a better accuracy than the Berlin Questionnaire [AUC = 0.676 (0.653-0.699)].

CONCLUSIONS

Despite one's intuition, surrogate markers of regional adiposity are not better than BMI in screening OSA. Combining measurements of global and/or regional adiposity did not have additional value in detecting OSA. The merely fair accuracy range of BMI and sleep questionnaires underscore the need for additional tools to improve OSA underdiagnosis.

The Relationship between Obstructive Sleep Apnea and Alzheimer's Disease

Obstructive sleep apnea (OSA) and Alzheimer's disease (AD) are highly prevalent conditions with growing impact on our aging society. While the causes of OSA are now better characterized, the mechanisms underlying AD are still largely unknown, challenging the development of effective treatments. Cognitive impairment, especially affecting attention and executive functions, is a recognized clinical consequence of OSA. A deeper contribution of OSA to AD pathogenesis is now gaining support from several lines of research. OSA is intrinsically associated with disruptions of sleep architecture, intermittent hypoxia and oxidative stress, intrathoracic and hemodynamic changes as well as cardiovascular comorbidities. All of these could increase the risk for AD, rendering OSA as a potential modifiable target for AD prevention. Evidence supporting the relevance of each of these mechanisms for AD risk, as well as a possible effect of AD in OSA expression, will be explored in this review.

Sleep-disordered breathing in C57BL/6J mice with diet-induced obesity

Obesity leads to sleep-disordered breathing (SDB) manifested by recurrent upper airway obstructions termed obstructive sleep apnea (OSA) and carbon dioxide retention due to hypoventilation. The objective of this work was to characterize breathing during sleep in C57BL6/J mice with diet-induced obesity (DIO). Arterial blood gas was measured in nine obese and nine lean mice during wakefulness. Nine male mice with DIO and six lean male C57BL/6J mice were head mounted with electroencephalogram (EEG) and electromyogram (EMG) electrodes. Sleep recordings were performed in the whole body plethysmography chamber; upper airway obstruction was characterized by the presence of inspiratory flow limitation in which airflow plateaus with increases in inspiratory effort. Obese mice showed significantly lower pH and higher partial pressure of arterial CO2 (PaCO2) in arterial blood gas compared to lean mice, 7.35 ± 0.04 versus 7.46 ± 0.06 (p < 0.001) and 38 ± 8 mm Hg versus 30 ± 5 mm Hg (p < 0.001). Obese mice had similar levels of minute ventilation to lean mice during sleep and wakefulness, despite higher body weight and temperature, indicating an increase in the metabolic rate and hypoventilation. Obese mice also showed baseline hypoxemia with decreased mean oxyhemoglobin saturation across sleep/wake states. Obese mice had a higher prevalence of flow-limited breathing compared to lean mice during sleep. However, the oxygen desaturation index in lean and obese mice did not differ. We conclude that DIO in mice leads to hypoventilation. Obesity also increases the frequency of inspiratory limited breaths, but it does not translate into progression of OSA.

Risk factors for incident anemia of chronic diseases: A cohort study

Objective

Anemia of chronic disease (ACD) refers to hypoproliferative anemia in the context of acute or chronic activation of the immune system. There is a paucity of prospective data addressing the risk factors for ACD development. An association between common chronic diseases and ACD was examined cross-sectionally and longitudinally.

Method

A cohort of 265,459 healthy participants without ACD at baseline were prospectively followed annually or biennially.

Results

During average follow-up period of 62 months, 4,906 participants developed ACD (incidence rate 3.58 per 1000 person-years). Multivariable-adjusted hazard ratio (HR) [95% confidence interval (CI)] for incident ACD comparing estimated glomerular filtration rate 30–60 and < 30 vs. ≥ 60 ml/min/1.73 m² were 3.93 [3.18–4.85] and 39.11 [18.50–82.69]; HRs [95% CI] for ACD comparing prediabetes and diabetes vs. normal were 1.19 [1.12–1.27] and 2.46 [2.14–2.84], respectively. HRs [95% CI] for incident ACD comparing body-mass-index (BMI) of < 18.5, 23–24.9 and ≥ 25 vs. 18.5–22.9 kg/m² were 0.89 [0.78–1.00], 0.89 [0.80–0.99] and 0.78 [0.66–0.91], respectively. HRs [95% CI] for incident ACD comparing prehypertension and hypertension vs. normal were 0.79 [0.73–0.86] and 1.10 [0.99–1.23], respectively. Metabolic syndrome, hypertension, chronic liver disease, and chronic obstructive pulmonary disease were not associated with incident ACD.

Conclusions

The severity of chronic kidney disease and diabetic status were independently associated with an increased incidence of ACD, whereas prehypertension and an increasing BMI were significantly associated with decreased risk of ACD.

Serum Uric Acid Is Independently Associated with Risk of Obstructive Sleep Apnea-Hypopnea Syndrome in Chinese Patients with Type 2 Diabetes

Purpose

We aimed to investigate the association between serum uric acid (SUA) levels and obstructive sleep apnea-hypopnea syndrome (OSAHS) in patients with type 2 diabetes.

Methods

A cross-sectional study of 212 type 2 diabetes mellitus (T2DM) patients was conducted in Xiamen, China. All patients underwent polysomnography (PSG) recordings for OSAHS diagnosis. Patients were grouped according to the apnea-hypopnea index (AHI) as mild (5-14.9), moderate (15-29.9), and severe (≧30) OSAHS. Patients with AHI ≤ 4.9 served as the control group. Weight, body mass index (BMI), SUA, liver function, renal function, blood pressure, lipid profiles, and glycemic parameters were measured.

Results

A total of 158 patients (101 men and 57 women) with complete data were analyzed in this study. 127 patients were identified as OSAHS. Among the 127 patients with OSAHS, 56 (44.1%), 37 (29.1%), and 34 (26.8%) had mild, moderate, and severe OSAHS, respectively. Correlation analyses showed that the SUA level was significantly related to the apnea-hypopnea index (AHI) (r = 0.194, p = 0.016). The level of SUA was significantly higher among OSAHS patients compared to the control group (control group: 333.14 ± 80.52 μmol/L, mild group: 345.50 ± 90.27 μmol/L, moderate group: 363.59 ± 134.26 μmol/L, and severe group: 428.37 ± 123.58 μmol/L and p = 0.029). Multivariable logistic regression analyses showed that SUA was the independent risk factor for OSAHS (OR: 1.006, 95% CI: 1.001-1.011, p = 0.020).

Conclusions

The SUA level is significantly associated with the severity of OSAHS and should be controlled when managing OSAHS.

Clinical Prediction Model for Obstructive Sleep Apnea among Adult Patients with Habitual Snoring

OBJECTIVE

To identify standard clinical parameters that may predict the presence and severity of obstructive sleep apnea/hypopnea syndrome (OSA).

DESIGN

Case series with chart review.

SETTING

Tertiary academic medical center.

SUBJECTS AND METHODS

A total of 325 adult patients (274 men and 51 women; mean age, 44.2 years) with habitual snoring completed comprehensive polysomnography and anthropometric measurements, including modified Mallampati grade (also known as updated Friedman's tongue position [uFTP]), tonsil size grading, uvular length, neck circumference, waist circumference, hip circumference, and body mass index (BMI).

RESULTS

When the aforementioned physical parameters were correlated singly with the apnea/hypopnea index (AHI), we found that sex, uFTP, tonsil size grading, neck circumference, waist circumference, hip circumference, thyroid-mental distance, and BMI grade were reliable predictors of OSA. When all important factors were considered in a multiple stepwise regression analysis, an estimated AHI can be formulated by factoring sex, uFTP, tonsil size grading, and BMI grade as follows: -43.0 + 14.1 × sex + 12.8 × uFTP + 5.0 × tonsil size + 8.9 × BMI grade. Severity of OSA can be predicted with a receiver operating characteristic curve. Predictors of OSA can be further obtained by the "OSA score."

CONCLUSION

This study has distinguished the correlations between sex, uFTP, tonsil size, and BMI grade and the presence and severity of OSA. An OSA score might be beneficial in identifying patients who should have a full sleep evaluation.