Sex differences in the association of regional fat distribution with the severity of obstructive sleep apnea

Association between obstructive sleep apnea risk and type 2 diabetes among Emirati adults: results from the UAE healthy future study

Introduction

Obstructive sleep apnea (OSA) can have negative impacts on the health outcomes of individuals with type 2 diabetes. However, in the United Arab Emirates (UAE), there is a lack of understanding regarding the relationship between OSA and type 2 diabetes despite the significant implications it has on health. The primary objective of this study is to investigate the association between OSA risk and type 2 diabetes, associated risk factors, and gender differences in OSA symptoms among Emirati adults.

Methods

We conducted a cross-sectional analysis of the baseline data from the UAE Healthy Future Study (UAEHFS) collected between February 2016 and March 2023. Our sample consisted of 4578 participants aged 18-71 who completed the STOP-BANG survey, provided body measurements and blood samples. We stratified the patients according to their OSA risk and diabetes. We used univariate and multivariate logistic regression models to analyze the relationship between OSA risk and type 2 diabetes and to identify factors associated with risk for OSA and type 2 diabetes. We estimated odds ratios (ORs) with corresponding 95% confidence intervals (95% CI).

Results

The mean age was 27.5 years (± 8.35), and 55.81% (n=2555) were men. The overall prevalence of high risk for OSA was 16.58% and was higher in men compared to women (26.46% vs 4.10%). Women reported feeling tired more often than men (68.02% vs 48.96%). Both genders have similar rates of stop breathing and BMI ≥ 35. There was a significant association between the OSA risk and type 2 diabetes in the unadjusted model (OR=2.44; 95% CI: 1.78-3.35; p-value <0.0001) and (OR=6.44; 95% CI: 4.32-9.59; p-value < 0.0001) among those who reported intermediate and high OSA risk, respectively. After adjusting the model for education attainment, marital status, waist circumference, and smoking, the association remained significant between diabetes and OSA risk, with an OR of 1.65 (95%CI: 1.18-2.32; p-value =0.004) for intermediate OSA risk and 3.44 (95%CI: 2.23-5.33; p-value <0.0001) for high OSA risk.

Conclusions

This study conducted in the UAE found a significant correlation between OSA risk and type 2 diabetes. We suggest introducing routine screening of OSA for individuals with diabetes.

Sex differences in sleep, circadian rhythms, and metabolism: Implications for precision medicine

The number of individuals experiencing sleep loss has exponentially risen over the past decades. Extrapolation of laboratory findings to the real world suggests that females are more affected by extended wakefulness and circadian misalignment than males are. Therefore, long-term effects such as sleep and metabolic disorders are likely to be more prevalent in females than in males. Despite emerging evidence for sex differences in key aspects of sleep-wake and circadian regulation, much remains unknown, as females are often underrepresented in sleep and circadian research. This narrative review aims at highlighting 1) how sex differences systematically impinge on the sleep-wake and circadian regulation in humans, 2) how sex differences in sleep and circadian factors modulate metabolic control, and 3) the relevance of these differences for precision medicine. Ultimately, the findings justify factoring in sex differences when optimizing individually targeted sleep and circadian interventions in humans.

Association between Neck Circumference and Thyroid Disease: Findings of a Nationwide Cross-Sectional Study in Korea

Background

There were contradictory reports about the relationship between neck circumference (NC) and thyroid status. This study aimed to compare the NCs of Korean adults with or without thyroid disease.

Methods

The data of 8,198 subjects (aged 40-80 yr) that participated in the 2019-2020 Korean National Health and Nutrition Examination Survey were subjected to analysis. NCs were measured by trained staff to an accuracy of ±0.1 cm with a tape measure. Multiple logistic models were used to assess the prevalence of thyroid disease by NC level among men and pre- and postmenopausal women.

Results

Approximately 5% of subjects had a history of thyroid disease. In contrast to men and postmenopausal women, premenopausal women with a larger NC had a significantly higher prevalence of thyroid disease (P-value=0.025).

Conclusion

A large NC is significantly associated with thyroid disease among premenopausal Korean women.

Anthropometric measures and obstructive sleep apnea in children and adolescents: a systematic review of the literature and meta-analysis

BACKGROUND

Anthropometric measurements can be used to identify children at risk of developing obstructive sleep apnea (OSA). The study aimed to assess which anthropometric measurements (AMs) are most associated with an increased predisposition to develop OSA in healthy children and adolescents.

METHODS

We performed a systematic review (PROSPERO #CRD42022310572) that searched eight databases and gray literature.

RESULTS

In eight studies with low-to-high risk of bias, investigators reported the following AMs: body mass index (BMI), neck circumference, hip circumference, waist-to-hip ratio, neck-to-waist ratio, waist circumference, waist-to-height ratio, and facial AMs. The meta-analysis showed that the OSA group had an average of 1.00 cm greater for the neck circumference (p < 0.001; Cohen's d = 2.26 [0.72, 5.23]), 3.07 cm greater for the waist circumference (p = 0.030; Cohen's d = 0.28 [0.02, 0.53]), 3.96 cm greater for the hip circumference (p = 0.040; Cohen's d = 0.28 [0.02, 0.55]), 5.21° greater for the cervicomental angle (p = 0.020; Cohen's d = 0.31 [0.03, 0.59]), and 1.23° greater for maxillary-mandibular relationship angle (p < 0.001; Cohen's d = 0.47 [0.22, 0.72]) than the control group. The mandibular depth angle had a reduction of 1.86° (p = 0.001; Cohen's d = -0.36° [-0.65, -0.08]) in control than in patients with OSA. The BMI (p = 0.180), waist-to-hip ratio (p = 0.280), neck-to-waist ratio (p = 0.070), maxillary depth angle (p = 0.250), and upper/lower face height ratio (p = 0.070) showed no significant differences between groups.

CONCLUSIONS

Compared to the control group, the OSA group exhibited a greater mean difference in neck circumference, the only anthropometric measurement with high certainty of evidence.

Longitudinal risk factors for obstructive sleep apnea: A systematic review

Despite substantial disease burden, existing evidence on the risk factors for obstructive sleep apnea (OSA) have been derived primarily from cross-sectional studies without determining temporality. Therefore, we aimed to systematically synthesize the literature on longitudinal risk factors for sleep study-assessed OSA and questionnaire-assessed probable OSA from cohort studies in the general adult population settings. We systematically searched Embase and Medline (on OVID) databases. Eleven studies met the inclusion criteria. Meta-analyses were not conducted due to methodological heterogeneity of exposure and outcome measurements. There was consistent evidence that weight gain was associated with incident (n = 2) and greater severity (n = 2) of OSA. One study each observed an association of higher baseline body-mass index, male sex, asthma, a specific genetic polymorphism in rs12415421, and insulin resistance/hyperglycemia, with incident OSA. Long-term exposure to ambient air pollution (NO2, n = 1) was associated with OSA, and menopausal transitions (n = 1) with higher apnea-hypopnea index. There were no eligible studies on long-term smoking or alcohol use. In conclusion, approximately 10% increase in weight, especially in males, might alert clinicians to consider potential or worsening OSA. Large, well-designed longitudinal studies are needed to consolidate knowledge on other associations with OSA development, especially on potentially modifiable risk factors.

The effect of surgical weight loss on upper airway fat in obstructive sleep apnoea

PURPOSE

Obesity is a reversible risk factor for obstructive sleep apnoea (OSA). Weight loss can potentially improve OSA by reducing fat around and within tissues surrounding the upper airway, but imaging studies are limited. Our aim was to study the effects of large amounts of weight loss on the upper airway and volume and fat content of multiple surrounding soft tissues.

METHODS

Participants undergoing bariatric surgery were recruited. Magnetic resonance imaging (MRI) was performed at baseline and six-months after surgery. Volumetric analysis of the airway space, tongue, pharyngeal lateral walls, and soft palate were performed as well as calculation of intra-tissue fat content from Dixon imaging sequences.

RESULTS

Among 18 participants (89% women), the group experienced 27.4 ± 4.7% reduction in body weight. Velopharyngeal airway volume increased (large effect; Cohen's d [95% CI], 0.8 [0.1, 1.4]) and tongue (large effect; Cohen's d [95% CI], - 1.4 [- 2.1, - 0.7]) and pharyngeal lateral wall (Cohen's d [95% CI], - 0.7 [- 1.2, - 0.1]) volumes decreased. Intra-tissue fat decreased following weight loss in the tongue, tongue base, lateral walls, and soft palate. There was a greater effect of weight loss on intra-tissue fat than parapharyngeal fat pad volume (medium effect; Cohen's d [95% CI], - 0.5 [- 1.2, 0.1], p = 0.083).

CONCLUSION

The study showed an increase in velopharyngeal volume, reduction in tongue volume, and reduced intra-tissue fat in multiple upper airway soft tissues following weight loss in OSA. Further studies are needed to assess the effect of these anatomical changes on upper airway function and its relationship to OSA improvement.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Topography of associations between cardiovascular risk factors and myelin loss in the ageing human brain

Our knowledge of the mechanisms underlying the vulnerability of the brain's white matter microstructure to cardiovascular risk factors (CVRFs) is still limited. We used a quantitative magnetic resonance imaging (MRI) protocol in a single centre setting to investigate the cross-sectional association between CVRFs and brain tissue properties of white matter tracts in a large community-dwelling cohort (n = 1104, age range 46-87 years). Arterial hypertension was associated with lower myelin and axonal density MRI indices, paralleled by higher extracellular water content. Obesity showed similar associations, though with myelin difference only in male participants. Associations between CVRFs and white matter microstructure were observed predominantly in limbic and prefrontal tracts. Additional genetic, lifestyle and psychiatric factors did not modulate these results, but moderate-to-vigorous physical activity was linked to higher myelin content independently of CVRFs. Our findings complement previously described CVRF-related changes in brain water diffusion properties pointing towards myelin loss and neuroinflammation rather than neurodegeneration.

Genome-wide association study of obstructive sleep apnoea in the Million Veteran Program uncovers genetic heterogeneity by sex

BACKGROUND

Genome-wide association studies (GWAS) for obstructive sleep apnoea (OSA) are limited due to the underdiagnosis of OSA, leading to misclassification of OSA, which consequently reduces statistical power. We performed a GWAS of OSA in the Million Veteran Program (MVP) of the U.S. Department of Veterans Affairs (VA) healthcare system, where OSA prevalence is close to its true population prevalence.

METHODS

We performed GWAS of 568,576 MVP participants, stratified by biological sex and by harmonized race/ethnicity and genetic ancestry (HARE) groups of White, Black, Hispanic, and Asian individuals. We considered both BMI adjusted (BMI-adj) and unadjusted (BMI-unadj) models. We replicated associations in independent datasets, and analysed the heterogeneity of OSA genetic associations across HARE and sex groups. We finally performed a larger meta-analysis GWAS of MVP, FinnGen, and the MGB Biobank, totalling 916,696 individuals.

FINDINGS

MVP participants are 91% male. OSA prevalence is 21%. In MVP there were 18 and 6 genome-wide significant loci in BMI-unadj and BMI-adj analyses, respectively, corresponding to 21 association regions. Of these, 17 were not previously reported in association with OSA, and 13 replicated in FinnGen (False Discovery Rate p-value < 0.05). There were widespread significant differences in genetic effects between men and women, but less so across HARE groups. Meta-analysis of MVP, FinnGen, and MGB biobank revealed 17 additional, previously unreported, genome-wide significant regions.

INTERPRETATION

Sex differences in genetic associations with OSA are widespread, likely associated with multiple OSA risk factors. OSA shares genetic underpinnings with several sleep phenotypes, suggesting shared aetiology and causal pathways.

FUNDING

Described in acknowledgements.

A risk-predictive model for obstructive sleep apnea in patients with chronic obstructive pulmonary disease

Background

Obstructive sleep apnea syndrome (OSA) is increasingly reported in patients with chronic obstructive pulmonary disease (COPD). Our research aimed to analyze the clinical characteristics of patients with overlap syndrome (OS) and develop a nomogram for predicting OSA in patients with COPD.

Methods

We retroactively collected data on 330 patients with COPD treated at Wuhan Union Hospital (Wuhan, China) from March 2017 to March 2022. Multivariate logistic regression was used to select predictors applied to develop a simple nomogram. The area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCA) were used to assess the value of the model.

Results

A total of 330 consecutive patients with COPD were enrolled in this study, with 96 patients (29.1%) confirmed with OSA. Patients were randomly divided into the training group (70%, n = 230) and the validation group (30%, n = 100). Age [odds ratio (OR): 1.062, 1.003–1.124], type 2 diabetes (OR: 3.166, 1.263–7.939), neck circumference (NC) (OR: 1.370, 1.098–1,709), modified Medical Research Council (mMRC) dyspnea scale (OR: 0.503, 0.325–0.777), Sleep Apnea Clinical Score (SACS) (OR: 1.083, 1.004–1.168), and C-reactive protein (CRP) (OR: 0.977, 0.962–0.993) were identified as valuable predictors used for developing a nomogram. The prediction model performed good discrimination [AUC: 0.928, 95% confidence interval (CI): 0.873–0.984] and calibration in the validation group. The DCA showed excellent clinical practicability.

Conclusion

We established a concise and practical nomogram that will benefit the advanced diagnosis of OSA in patients with COPD.

From Beneath the Skin to the Airway Wall: Understanding the Pathological Role of Adipose Tissue in Comorbid Asthma-Obesity

This article provides a contemporary report on the role of adipose tissue in respiratory dysfunction. Adipose tissue is distributed throughout the body, accumulating beneath the skin (subcutaneous), around organs (visceral), and importantly in the context of respiratory disease, has recently been shown to accumulate within the airway wall: "airway-associated adipose tissue." Excessive adipose tissue deposition compromises respiratory function and increases the severity of diseases such as asthma. The mechanisms of respiratory impairment are inflammatory, structural, and mechanical in nature, vary depending on the anatomical site of deposition and adipose tissue subtype, and likely contribute to different phenotypes of comorbid asthma-obesity. An understanding of adipose tissue-driven pathophysiology provides an opportunity for diagnostic advancement and patient-specific treatment. As an exemplar, the potential impact of airway-associated adipose tissue is highlighted, and how this may change the management of a patient with asthma who is also obese. © 2023 American Physiological Society. Compr Physiol 13:4321-4353, 2023.

Effects of opioid-free propofol or remimazolam balanced anesthesia on hypoxemia incidence in patients with obesity during gastrointestinal endoscopy: A prospective, randomized clinical trial

There are presently no consensuses on the optimal sedation strategy for obese patients during gastrointestinal endoscopy. This study aim to explore the effects of opioid-free propofol or remimazolam balanced anesthesia on hypoxemia incidence in patients with obesity. A total of 264 patients were randomized to remimazolam + esketamine group (group R) or propofol + esketamine group (group P). Anesthesia in group P was administrated by propofol, esketamine and in group R by remimazolam, esketamine. The primary outcome was incidence of hypoxemia. Secondary outcomes were the time to loss of consciousness (LoC) and to recovery and the incidence of intraoperative and postoperative adverse reactions. We found the incidence of mild hypoxemia in group R was similar to that in group P (14.2% vs. 11.5%, p = 0.396). The incidence of severe hypoxemia in group R was significantly lower than Group P (4.2% vs. 9.2%, p = 0.019). The time to LoC in group R was longer than group P [Median (interquartile range, IQR): 53 s (45 to 61) vs. 50 s (42 to 54), p = 0.001]. The time to recovery from anesthesia in group R was less than group P [Median (IQR): 48 min (41 to 58) vs. 55.5 min (46 to 67), p<0.001]. There was no significant difference in the incidence of adverse events (p > 0.05 for all). We concluded that compared with propofol combined with esketamine, remimazolam combined with esketamine can reduce the incidence of severe hypoxemia during gastrointestinal endoscopy in obese patients. Clinical Trial Registration: www.chictr.org.cn, Identifier: ChiCTR2200065575.

Evaluating symptoms and polysomnographic findings among male and female children with obesity with and without obstructive sleep apnea

OBJECTIVE

Limited data regarding sex-based differences in the presentation and phenotype of obstructive sleep apnea (OSA) exists among children with obesity. The study objectives were to compare reported symptoms and polysomnogram (PSG) findings between children with obesity 1) with and without OSA and 2) males and females with OSA.

PATIENTS/METHODS

This cross-sectional study included children with obesity, aged 8-18 years, with a diagnostic PSG between 2015 and 2021, referred for evaluating sleep-related breathing. Patient demographics, anthropometrics, and PSG data were recorded. Symptoms were evaluated using Epworth Sleepiness Scale and Pediatric Sleep Questionnaire. Pubertal staging was collected using Tanner Stage questionnaire. PSG parameters, symptoms and pubertal stage were compared between sexes with and without OSA.

RESULTS

Of 148 children, 61 (41%) had OSA. Within the OSA group, 41/62 (69%) were male (p = 0.002). Males with OSA reported higher Pediatric Sleep Questionnaire scores compared to males without OSA (0.38 ± 0.2 vs 0.23 ± 0.1; p = 0.002). Males with OSA reported more trouble breathing (p = 0.04) and mouth breathing (p = 0.008) compared to females with OSA. Females with OSA showed longer sleep onset latency (45.8 ± 40.6 min vs 22.4 ± 26.7; p = 0.02) and higher supine obstructive-apnea hypopnea index (32.9 ± 31.1 vs 20.4 ± 18.4 events/hour; p = 0.02) compared to males with OSA. A significant interaction was found between male sex and waist-to-height ratio (β = 15.34, R² = 0.18, p = 0.05).

CONCLUSIONS

Sex differences in symptoms and phenotype of OSA exist among children with obesity. Such information is beneficial for early diagnosis and management to mitigate adverse outcomes and comorbidities.

Accuracy and modification of the STOP ‐bang questionnaire for screening patients with obstructive sleep apnea in China

Despite the high sensitivity of the STOP-Bang questionnaire [snoring, tiredness, observed apneas, high blood pressure, body mass index, age, neck size, gender] questionnaire (SBQ), which is widely used to screen individuals at high risk of obstructive sleep apnea (OSA), few studies have evaluated the discrimination related to sex in the SBQ. Therefore, our study aimed to assess whether SBQ performance is gender-related and modified by changing body mass index (BMI) and neck circumference (NC) cut-off values. A total of 470 patients attended the sleep centres. They were divided into moderate-to-severe OSA and non-moderate-to-severe OSA groups based on the apnea-hypopnea index (AHI) and the results of the SBQ screening. The predictive performance of the SBQ screening instrument was evaluated by 2 × 2 contingency tables and discriminatory ability, which was estimated from the area under the curve (AUC) obtained from receiver operating characteristic curve. Our results suggest that when screening for moderate-to-severe OSA, the original SBQ has higher sensitivity and lower specificity for men; however, women have higher specificity and lower sensitivity. The SBQ achieved the maximum AUC of 0.783 for men and 0.634 for women when the BMI cut-off value was established at 30 kg/m² and the NC cut-off value was established at 38 cm in men, and the BMI cut-off value was established at 25 kg/m² and the NC cut-off value at 36 cm in women. Balancing the optimal sensitivity and specificity, the cut-off value of the optimal modified SBQ total scores for men was determined to be ≥4 and ≥3 for women.

Development and assessment of a risk prediction model for moderate-to-severe obstructive sleep apnea

Background

OSA is an independent risk factor for several systemic diseases. Compared with mild OSA, patients with moderate-to-severe OSA have more severe impairment in the function of all organs of the body. Due to the current limited medical condition, not every patient can be diagnosed and treated in time. To enable timely screening of patients with moderate-to-severe OSA, we selected easily accessible variables to establish a risk prediction model.

Method

We collected 492 patients who had polysomnography (PSG), and divided them into the disease-free mild OSA group (control group), and the moderate-to-severe OSA group according to the PSG results. Variables entering the model were identified by random forest plots, univariate analysis, multicollinearity test, and binary logistic regression method. Nomogram were created based on the binary logistic results, and the area under the ROC curve was used to evaluate the discriminative properties of the nomogram model. Bootstrap method was used to internally validate the nomogram model, and calibration curves were plotted after 1,000 replicate sampling of the original data, and the accuracy of the model was evaluated using the Hosmer-Lemeshow goodness-of-fit test. Finally, we performed decision curve analysis (DCA) of nomogram model, STOP-Bang questionnaire (SBQ), and NoSAS score to assess clinical utility.

Results

There are 6 variables entering the final prediction model, namely BMI, Hypertension, Morning dry mouth, Suffocating awake at night, Witnessed apnea, and ESS total score. The AUC of this prediction model was 0.976 (95% CI: 0.962–0.990). Hosmer-Lemeshow goodness-of-fit test χ² = 3.3222 (P = 0.1899 > 0.05), and the calibration curve was in general agreement with the ideal curve. The model has good consistency in predicting the actual occurrence of moderate-to-severe risk, and has good prediction accuracy. The DCA shows that the net benefit of the nomogram model is higher than that of SBQ and NoSAS, with has good clinical utility.

Conclusion

The prediction model obtained in this study has good predictive power for moderate-to-severe OSA and is superior to other prediction models and questionnaires. It can be applied to the community population for screening and to the clinic for prioritization of treatment.

Validity Analysis of Neck Circumference as a Screening Test for Hypoxia Occurrence in Patients Undergoing Sedative Endoscopy

This study was performed to check the validity of and propose a cutoff point for measuring the neck circumference for screening hypoxia occurrence in patients undergoing sedative endoscopy. Data were collected from 168 patients who visited the Endoscopy Center of G University Hospital between 27 April 2020 and 12 June 2020 to undergo sedative endoscopy. Hypoxia occurrences were measured using sleep questionnaires (STOP-BANG and Berlin questionnaires), and the neck circumference measurements of the patients were compared. Neck circumference as a predictor of hypoxia and its sensitivity and specificity according to the cutoff values were high; thus, it is a valid screening test for hypoxia in patients undergoing sedative endoscopy. The most appropriate cutoff values for sitting neck circumference and lying neck circumference in men were 40.5 and 40.3, respectively, and those for women were 35.3 and 35.8, respectively. Hypoxia can be predicted in patients undergoing sedative endoscopy by measuring their neck circumference.

Incremental significance and sex discrepancies of neck circumference on the odds of ischaemic stroke: a multistage, population-based, cross-sectional study from Northeast China

OBJECTIVES

Accumulated evidence suggests that neck circumference (NC) is associated with cardiometabolic risk factors. However, limited studies are available regarding the association between NC or height normalised NC (neck-to-height ratio (NHR)) and risk of ischaemic stroke (IS) in the Chinese population. Therefore, we aimed at examining the associations between NC or NHR and odds of IS and exploring the discrepancies between men and women.

DESIGN

A multistage cluster cross-sectional study.

SETTING

A population-based study carried out in Northeast China.

METHODS

A cross-sectional study was undertaken in Northeast China between September 2017 and March 2019, involving 7236 men and 11 352 women, respectively. The median age of participants was 60.30 years, ranging from 40 to 97 years. The associations between NC or NHR and odds of IS were calculated using multiple logistic regression models. Dose-response relationships were depicted using restricted cubic spline functions. Reclassification analyses were carried out to determine the incremental significance of NC or NHR on the odds of IS.

RESULTS

In women, NC and NHR were significantly associated with the odds of IS, independent of traditional risk factors and other anthropometric parameters for obesity. The highest quartile of NC and NHR had a 1.60 (95% CI 1.16 to 2.22)-and 1.72 (95% CI 1.23 to 2.41) times higher odds of IS compared with the lowest quartile. Furthermore, the odds of IS increased by 1.10 (95% CI 1.01 to 1.20) and 1.12 (95% CI 1.02 to 1.22) times per 1 SD increase in NC and NHR, respectively. Reclassification analyses showed that the proportion of correct classification increased by 11.5% (95% CI 2.2% to 20.7%) and 22.8% (95% CI 13.5% to 32.0%) after the addition of NC or NHR into established models, respectively. However, the findings could not be replicated in men.

CONCLUSION

NC and NHR might be promising independent indicators for women IS. Their incremental value in the risk stratification of IS enables the individualised prevention of IS in women.

Sleep Measurements in Women

Sleep in women and men have been studied in several studies with higher prevalence of sleep complaints in women compared with men. Several factors can affect sleep and could be argued to contribute to sex and gender differences in general sleep. There are no differences in guidelines when measuring sleep in women but several sleep assessment tools have been validated or compared between sexes. Because there is still a lack of knowledge on sleep measurements in women, the present review aimed to produce an overview of the current knowledge of objective and subjective sleep measurements in women.

Associations of ambient air pollution with overnight changes in body composition and sleep-related parameters

This study aims to investigate the association of air pollution with overnight change in 4body composition and sleep-related parameters. Body composition of 197 subjects in New Taipei city was measured before and after sleep by bioelectric impedance analysis. Air pollutant data were collected from Taiwan Environmental Protection Administration. Sleep parameters were examined by polysomnography. We observed fine particulate matter (PM_2.5) decreased arterial oxygen saturation (SaO₂) and increased apnea-hypopnea index (AHI); NO₂ increased arousal, AHI, and decreased mean SaO₂; and O₃ inmcreased mean SaO₂. We observed 0.99-μg/m³ increase in PM_2.5 was associated with 18.8% increase in changes of right arm fat percentage (95% confidence interval (CI): 0.004, 0.375) and 0.011-kg increase in changes of right arm fat mass (95% CI: 0.000, 0.021). 2.45-ppb increase in NO₂ was associated with 0.181-kg decrease in changes of muscle mass (95% CI: -0.147, -0.001), 0.192-kg decrease in changes of fat free mass (95% CI: -0.155, -0.001), 21.1% increase in changes of right leg fat percentage (95% CI: 0.012, 0.160), and 21.3% increase in changes of left leg fat percentage (95% CI: 0.006, 0.168). 1.56-ppb increase in O₃ was associated with 29.3% decrease in changes of right leg fat percentage (95% CI: -0.363, -0.013), 0.058-kg increase in changes of right leg fat free mass (95% CI: 0.008, 0.066), and 0.059-kg increase in changes of right leg muscle mass (95% CI: 0.010, 0.066). We observed AHI was associated with overnight changes in fat percentage, total fat mass, muscle mass, bone mass, fat free mass, extracellular water, basal metabolic rate, leg fat percentage, leg fat mass, and trunk fat percentage (p < 0.05). In conclusion, exposure to air pollutants was associated with overnight body composition changes and sleep-related parameters. Nocturnal changes in total muscle mass and leg fat percentage likely contribute to the relationship between air pollution and obstructive sleep apnea.

Age-specific markers of adiposity in patients with obstructive sleep apnea

OBJECTIVES

Adiposity can have varying effects on the individual depending upon its distribution pattern. We assessed age-related distribution of adipose tissue by anthropometric measures and bioelectrical impedance analysis, as well as their association with obstructive sleep apnea (OSA) severity.

METHODS

Participants were 169 elderly (aged ≥ 65 years) and 142 non-elderly (aged < 65 years) referred for overnight polysomnography. The associations between obesity parameters and apnea-hypopnea index (AHI) were determine by univariate and multivariate linear regression analyses. Area under receiver operating characteristic curve (AUC) was used to access the predicting performance of some parameters.

RESULTS

Compared with non-elderly, elderly showed higher conicity index and visceral adiposity (VA)/subcutaneous adiposity (SA), lower body mass index (BMI), neck circumference, waist circumference, hip circumference and SA. Multiple regression analyses revealed that VA and VA/SA were independently associated with AHI in elderly (explained 17.2% of the AHI ^0.5 variability), while BMI and VA/SA were independently associated with AHI in non-elderly (explained 25.9% of the AHI ^0.5 variability), after adjusting for age, sex, cigarette smoking, alcohol drinking and main comorbidities. In elderly, VA over 128 cm² and VA/SA less than 0.41 resulted in sensitivity, specificity and AUC of 0.382, 0.790, 0.580 and 0.176, 0.947, 0.553 in predicting moderate-to-severe OSA, respectively. In non-elderly, BMI over 24.7 kg/m² and VA/SA over 0.54 resulted in sensitivity, specificity and AUC of 0.883, 0.484, 0.704 and 0.550, 0.710, 0.667 in predicting moderate-to-severe OSA, respectively.

CONCLUSIONS

VA is strongly associated with OSA severity in elderly, independently of general obesity as per BMI standards, while general adiposity appears to be more strongly associated with OSA severity in non-elderly. Our study supports age-specific approaches should be developed with respect to prediction and treatment of OSA.

The predictive value of photogrammetry for obstructive sleep apnea

STUDY OBJECTIVES

The aim of this study was to develop a prediction model for obstructive sleep apnea (OSA) based on photographic measurements of upper airway structures and to compare this to the model based on general physical examination.

METHODS

Participants with suspected OSA were recruited consecutively. General physical examination and photography of the oropharyngeal structures were performed prior to polysomnography. Logistic regression analysis was used to establish the prediction models.

RESULTS

A total of 197 eligible participants were included, and 74% were confirmed with OSA. The logistic regression model consisted of 4 photographic measurements (tongue area, uvula area, frenulum length, and retroposition distance) that classified 82.7% of the participants correctly and had 85.6% (95% confidence interval, 78.9-90.9%) sensitivity and 84.3% (95% confidence interval, 71.4-93.0%) specificity at the best cutoff point (0.71). The area under the receiver operating characteristics curve of the model was 0.90, which was higher than that of the model based on general physical measurements alone (area under the curve 0.80). The prediction performance further improved when photographic and general physical measurements were combined (area under the curve 0.93).

CONCLUSIONS

Detailed abnormality data of upper airway structures in OSA could be provided by photogrammetry. Prediction models comprising photographic measurements could be useful in the prediction of OSA.

CLINICAL TRIAL REGISTRATION

Registry: Chinese Clinical Trial Registry; Name: Mechanisms of cessation of respiratory events in patients with different phenotypes of obstructive sleep apnea; URL: http://www.chictr.org.cn/historyversionpuben.aspx?regno=ChiCTR2000031748; Identifier: ChiCTR2000031748.

Does neck circumference predict obstructive sleep apnea in children with obesity?

OBJECTIVES

Obstructive sleep apnea (OSA) affects 10-50% of children with obesity, but its identification is challenging and wait times for testing are long. Previous studies suggest that neck circumference (NC) and neck-to-height ratio (NHR) may predict OSA. Our objectives were to 1) evaluate associations of NC and NHR with OSA; 2) model NHR as a predictor of OSA, adjusting for age, sex, and Tanner stage; and 3) identify thresholds of NHR associated with OSA, in children with obesity.

METHODS

Participants were aged 8-17 years, with obesity (BMI >95%ile), undergoing polysomnography. Associations between NC and NHR with OSA were evaluated. NHR, age, sex and self-reported Tanner stage (early/late) were included in a negative binomial multiple regression model to predict obstructive apnea hypopnea index (OAHI).

RESULTS

71 children participated, with median age 14.8 years (IQR 12.6, 16.0), 54% male, median BMI z-score 2.5 (IQR 2.3, 2.7), and 77% late Tanner stage. OSA was severe in 18 children (25.4%), moderate in 12 (16.9%), and mild in 18 (25.4%). In the model, each 0.01 increase in NHR was associated with a 55% increase in OAHI (95% CI: 36%, 80%); boys had a 119% higher OAHI than girls (95% CI: 10%, 337%). Threshold NHR associated with moderate-severe OSA was 0.25 in females and 0.23 in males.

CONCLUSIONS

NHR and male sex independently predict OSA severity in children with obesity, adjusting for age and Tanner stage. Children with obesity and NHR above identified thresholds are more likely to have moderate-severe OSA, and may benefit from earlier polysomnography.

No Association between Neck Circumference and Free Triiodothyronine in Euthyroid Men

OBJECTIVE

Neck circumference (NC) is a simple anthropometric index for the assessment of upper body obesity. Thyroid hormones are closely related to obesity, body fat distribution indicators, and metabolic parameters. However, there are currently no reports on the association between NC and thyroid hormones in the Chinese population. This study aimed to explore the relationship between NC and thyroid hormones in men with normal thyroid function.

METHODS

A total of 737 euthyroid men from Shanghai communities were enrolled. Anthropometric parameters, including NC and waist circumference (WC), were measured. Serum thyroid hormones were measured by electrochemical luminescence immunoassay.

RESULTS

NC, WC, and body mass index (BMI) were significantly positively correlated with serum free triiodothyronine (FT3) (all P < 0.05). FT3 levels all presented significant upward trends with the increase in NC, WC, or BMI quartiles (all P for trend < 0.05), whereas there were no significant correlations between the three obesity indices and free thyroxine or thyroid-stimulating hormone (both P > 0.05). After adjustment for metabolic confounding factors such as age, blood pressure, blood glucose, lipid profiles, and CRP in multiple linear regression analysis, the correlation between FT3 and NC disappeared (standardized β = -0.015, P=0.705), and FT3 remained significantly associated with WC (standardized β = 0.103, P=0.012) and BMI (standardized β = 0.082, P=0.047).

CONCLUSIONS

In euthyroid men from Shanghai communities, there was no independent correlation between serum FT3 levels and NC. The trial was registered with ChiCTR1900024011.

A Systematic Review and Meta-Analysis of Prevalence of Obstructive Sleep Apnea in Iranian Patients with Cardiovascular Disease: Perspective of Prevention, Care and Treatment

BACKGROUND

Obstructive sleep apnea (OSA) is a chronic breathing disorder during sleep. It is prevalent among patients with cardiovascular disease (CVD) and can increase its severity and mortality. Various studies have reported different results in Iran. This systematic review and meta-analysis aimed to determine the prevalence of OSA in Iranian patients with CVD.

MATERIALS AND METHODS

In this study, eight papers published in Persian and English languages were reviewed. The articles were searched using the following keywords and all their possible combinations: "obstructive sleep apnea", "sleep-disordered breathing", "sleep apnea", "OSA", "cardiovascular disease", "hypertension", and "Iran". Scientific databases, including the Scientific Information Database (SID), Magiran, Web of Science, PubMed, and Scopus, were searched with no time limitations. Data were analyzed using a meta-analysis and a random effects model. Besides, heterogeneity was assessed using the I² statistic. Data analysis was performed in Stata version 11.

RESULTS

The review of eight studies, with a total sample size of 1646 patients, showed that the prevalence of OSA was 59.21% (95% CI: 53.11-65.32) among CVD patients. Also, the prevalence of OSA was higher in men (60.12%; 95% CI: 60.12-82.54) than in women (41.01%; 95% CI: 16.08-65.94). Besides, it was estimated to be higher based on the STOP and STOP-BANG questionnaires (63%; 95% CI: 52.89-73.10) as compared to the Berlin questionnaire (56.63%; 95% CI: 49.20-64.06).

CONCLUSION

More than half of Iranian CVD patients have OSA. Therefore, identifying high-risk patients to reduce the adverse effects of sleep apnea seems necessary.

Metabolic bariatric surgery as a treatment for obstructive sleep apnea hypopnea syndrome: review of the literature and potential mechanisms

Obstructive sleep apnea hypopnea syndrome (OSAHS) is closely related to obesity and can cause multiple organs and systems damage. Metabolic bariatric surgery (MBS) is presently the only long-term effective treatment and an important strategy for severely obese population, which also provides a novel therapeutic for obese patients with OSAHS, especially in patients with poor continuous positive air pressure (CPAP) adherence. To date, the resolution mechanism of OSAHS in obese patients after MBS has not been fully clarified. In addition, there is no specific metabolic bariatric surgical treatment of OSAHS guidelines. Therefore, this review provides an update on the relationship between OSAHS and MBS for highlighting the importance of weight loss strategies for obese patients with OSAHS.

Sex-Specific Intubation Biomechanics: Intubation Forces Are Greater in Male Than in Female Patients, Independent of Body Weight

Background

Studies of head, neck, and cervical spine morphology and tissue material properties indicate that cervical spine biomechanics differ between adult males and females. These differences result in sex-specific cervical spine kinematics and injury patterns in response to standardized loading conditions. Because direct laryngoscopy and endotracheal intubation require the application of a load to the cervical spine, intubation biomechanics should be sex-specific. The aim of this study was to determine if intubation forces during direct laryngoscopy differ between male and female patients and, if so, is the difference independent of body weight.

Methods

We pooled original data from three previously published adult clinical intubation studies that used methodologically reliable intubation force measurements (measured total laryngoscope force applied to the tongue, and force values were insensitive to or accounted for other laryngoscope blade forces). All patients had undergone direct laryngoscopy and orotracheal intubation with a Macintosh 3 blade under general anesthesia. Patient data included sex, age, height, weight, and maximum intubation force. Least squares multivariable linear regression was performed between the dependent variable (maximum intubation force) and two independent variables (patient sex and patient weight). A third term was added for the interaction between patient sex and weight.

Results

Among all patients (males n=42, females n=59), the median intubation force was 42.2 N (25^th to 75^th percentiles: 31.5 to 57.4 N). While controlling for patient body weight, intubation force differed between the sexes; P=0.011, with greater intubation force in male patients. While controlling for patient sex, there was a positive association between patient body weight and intubation force; P=0.009. In addition, there was a significant interaction between patient sex and weight; P=0.002, with intubation force in male patients having greater dependence on body weight. The difference in intubation force between male and female patients who had the same body weight exceeded 5 N when body weight exceeded 75 kg, and intubation force differences between male and female patients increased as patient body weight increased. Additional analyses using robust regression and using body mass index instead of weight provided comparable results.

Conclusion

In adult patients, the biomechanics of direct laryngoscopy and intubation are sex-specific. Our findings support the need to control for patient sex and weight in future clinical and laboratory studies of the human cervical spine and head and neck biomechanics.

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.

Associations of Inflammation, Physical Activity, and Sleep in a Diverse Population of Women

Background: Cardiovascular disease (CVD) is the leading cause of mortality in United States with a recent rise seen in young adults, particularly women. Systemic inflammation, physical activity, and sleep are each individually linked to CVD risk. Whether there is an interaction of these variables, however, is unclear. We evaluated physical activity and sleep among racially ethnically diverse women, ages 20-79 years, to assess associations with systemic inflammation. Methods: We performed a cross-sectional study of 506 women (61% racial/ethnic minority; mean (standard deviation [SD]) age = 37 [15.7] years, body mass index 26.0 [5.7] kg/m²) enrolled in the American Heart Association (AHA) Go Red for Women Strategically Focused Research Network at Columbia University Irving Medical Center (CUIMC). Inflammation, assessed by C-reactive protein (CRP), was analyzed in the Biomarkers Core Laboratory at CUIMC. Physical activity and sleep were assessed using validated questionnaires. Multivariable models adjusted for demographic and clinical confounders were used to evaluate associations between CRP, physical activity, and sleep. Results: Mean (SD) physical activity was 282 (557.2) minutes/week, and mean (SD) sleep duration was 6.75 (1.24) hours/night. Mean CRP was 2.08 (3.56), and 17% of participants were categorized as high risk for obstructive sleep apnea (OSA). Participants who slept <6 hours/night were less likely to be physically active ≥150 minutes/week (odds ratios, ORs [95% confidence interval, CI]: 0.53 [0.33-0.84]). This association was nonsignificant after adjustment. High risk of OSA was associated with CRP ≥2 mg/L (OR [95% CI]: 1.91 [1.11-3.30]) following adjustment. Stratification by race/ethnicity showed that high risk of OSA was associated with CRP ≥2 mg/L among racial/ethnic minorities but not white women (OR [95% CI]: 2.75 [1.43-5.30] vs. 0.94 [0.31-2.88]). Conclusion: High risk of OSA and elevated CRP was significantly associated in women, particularly minority women. Both play a role in CVD, highlighting potential causes for the increased risk of CVD in younger women.

Nutritional Status and Dietary Patterns in Adults with Severe Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is associated with daytime sleepiness, obesity, and lifestyle and dietary changes. The potential role of diet in OSA has been largely unexplored. The aim of the study was to assess nutritional status and dietary patterns in OSA patients. The study was conducted in 137 adult patients (48 women and 89 men) aged 31-79 suffering from OSA. The following diagnostic procedures were undertaken: polysomnography, anthropometric measurements, and a dietary pattern questionnaire. We found that 128 (93.4%) patients were overweight or obese with the mean body mass index (BMI) of 33.2 ± 6.1 kg/m² and weight of 98.0 ± 20.2 kg. The mean percentage of total body fat was 45.0 ± 5.5% in women and 32.5 ± 5.5% in men. Obesity was associated with the severity of OSA, expressed by apnea/hypopnea index. We further found that the waist-to-hip ratio in women, but the neck circumference or percentage of body fat in men, characterizes best the OSA patients. Referring to dietary habits, half of the patients consumed white bread on a daily basis, 35.8% of them had whole grain bread in the diet, and only 16.8% consumed fish at least two portions a week. A third of patients used butter as a spread for bread or a source of fat for cooking, 2.9% of them used soft margarine, and 20.4% used olive or canola oil. Fruits and vegetables were consumed by 60% and 38% of patients, respectively. Refined sugar and sweets were used by 31.4% of patients every day. We conclude that excessive body weight, which may portend the development of OSA, is characterized by different anthropometric variables in men and women. Further, improper dietary habits seem conducive to the gain in body weight and thus may be at play in the pathogenesis of OSA.

Improvement in Nocturnal Hypoxemia in Obese Patients with Obstructive Sleep Apnea after Bariatric Surgery: a Meta-Analysis

OBJECTIVE

To conduct a meta-analysis examining the effects of bariatric surgery on nocturnal hypoxemia in obese patients with obstructive sleep apnea (OSA).

METHODS

PubMed, EMBASE, Cochrane Library, and Web of Science were searched (the last search date was June 10, 2018) to identify relevant clinical studies. The mean arterial oxygen saturation (MeanSaO₂), nadir oxygen saturation (NadirSaO₂), apnea hypopnea index (AHI), and body mass index (BMI) data during the perioperative period were extracted and analyzed using a random effects model. Then, we performed subgroup and sensitivity analyses and calculated the publication bias to assess the between-study heterogeneity.

RESULTS

In total, 15 studies with 636 patients were included; 13 were prospective observational trials, 1 was a randomized controlled trial (RCT), and 1 was a retrospective trial. After surgery, the MeanSaO₂ and NadirSaO₂ increased by 1.36 [95% CI (0.72, 2.00)] and 1.08 [95% CI (0.68, 1.49)], respectively, and the AHI and BMI decreased by 1.11 [95% CI (0.82, 1.40)] and 1.97 [95% CI (1.67, 2.27)], respectively. However, the heterogeneity across all trials was high; we identified some of the sources of that heterogeneity through subsequent subgroup and sensitivity analyses.

CONCLUSIONS

Bariatric surgery is effective at improving nocturnal hypoxemia in obese patients with OSA; it also reduces body weight and the number of apnea events. More randomized controlled and comparative trials are necessary in the future to confirm our findings and to explore the potential underlying mechanisms.

The use of visceral adiposity variables in the prediction of obstructive sleep apnea: evidence from a large cross-sectional study

PURPOSE

The purposes of this study were to evaluate the ability of visceral adiposity variables [the lipid accumulation product (LAP), the visceral adiposity index (VAI), and the triglyceride-glucose index (TyG)] in predicting obstructive sleep apnea hypopnea syndrome (OSAHS) and to determine the effect of sex on the prediction.

METHODS

A total of 5539 subjects admitted to the sleep center for suspected OSAHS were consecutively recruited from 2007 to 2016. Anthropometric measurements, biological indicators, Epworth sleepiness scale score, and polysomnographic variables were collected. Prediction models for diagnosing OSAHS were established in the test group by logistic regression and verified in the validation group by receiver operating characteristic (ROC) curves.

RESULTS

A total of 4703 patients were included in total. LAP and TyG were of moderate diagnostic accuracy for OSAHS, with the diagnostic efficiency differing between men and women. A prediction model was developed that combined visceral adiposity indicators with waist circumstance and the lowest SpO₂. The sensitivity of those indicators were both 84% in men and women, respectively, and their specificity were both 90%. In addition, the model was confirmed in the validation group with a sensitivity and specificity of 83% and 85% in men and 85% and 84% in women.

CONCLUSIONS

LAP and TyG were of moderate efficiency in screening for OSAHS. The prediction model provides a simple and practical screening tool for OSAHS.

Role of menopause and hormone replacement therapy in sleep-disordered breathing

There are suggestions that the loss of female sex hormones following menopause is critical for the development or progression of sleep-disordered breathing (SDB). We conducted a review of the literature on the role of menopause and hormone replacement therapy (HRT) in SDB risk. There is an increase in SDB during the menopausal transition period, but data on an effect beyond that of increasing age and changes in body habitus are weak or absent. Early community-based, observational studies reported a protective effect by HRT on SDB prevalence, but this could possibly be explained as a healthy user effect. Interventional studies of the effect of HRT on SDB are sparse, with only a few randomized placebo-controlled studies, often performed on small samples of women without clinically significant SDB. HRT regimens have varied and all the studies are fairly old. They do not definitely assure the alleviation of SDB and HRT cannot thus be recommended as treatment for SDB. It is concluded that there is no evidence that female sex hormone changes during menopause per se are able to explain the increase in SDB in midlife women and conclusions on the effect of HRT on SDB cannot be drawn from the current literature.

Endothelial Function of Patients with Morbid Obesity Submitted to Roux-en-Y Gastric Bypass With and Without Obstructive Sleep Apnea-Hypopnea Syndrome

BACKGROUND

Obesity is associated with obstructive sleep apnea-hypopnea syndrome (OSA) and both induce endothelial dysfunction. However, the effect of OSA on endothelial function after bariatric surgery has not been investigated yet.

OBJECTIVES

This study aims to evaluate the impact of weight loss on endothelial function in patients with and without obstructive sleep apnea (OSA) in the first 6 months after bariatric surgery.

SETTING

This study was conducted at a university hospital, in Brazil.

METHODS

The sample consisted of 56 patients homogeneously divided into groups with and without OSA. All patients underwent Roux-en-Y gastric bypass (RYGB), and the diagnosis of OSA was performed by polysomnography. The patients were evaluated preoperatively and 6 months after surgery. The evaluations included anthropometric measures, electrical bioimpedance, clinical symptoms of OSA, and endothelial function (flow-mediated dilation). RYGB improved the anthropometric, bioimpedance, and endothelial function results in both groups.

RESULTS

Patients presented a significant clinical improvement in OSA symptoms throughout the study. However, patients with OSA had an improvement in the endothelial function 2.5% lower (p < 0.001) than patients without APNEA syndrome.

CONCLUSION

This study demonstrates that the existence of OSA prior to bariatric surgery interferes in the improvement of endothelial function.

A Global Comparison of Anatomic Risk Factors and Their Relationship to Obstructive Sleep Apnea Severity in Clinical Samples

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is a global health issue and is associated with obesity and oropharyngeal crowding. Global data are limited on the effect of ethnicity and sex on these relationships. We compare associations between the apnea-hypopnea index (AHI) and these risk factors across ethnicities and sexes within sleep clinics.

METHODS

This is a cross-sectional, multicenter study of patients with OSA from eight sleep centers representing the Sleep Apnea Global Interdisciplinary Consortium (SAGIC). Four distinct ethnic groups were analyzed, using a structured questionnaire: Caucasians (Australia, Iceland, Germany, United States), African Americans (United States), Asians (Taiwan), and South Americans (Brazil). Regression analyses and interaction tests were used to assess ethnic and sex differences in relationships between AHI and anthropometric measures (body mass index [BMI], neck circumference, waist circumference) or Mallampati score.

RESULTS

Analyses included 1,585 individuals from four ethnic groups: Caucasian (60.6%), African American (17.5%), Asian (13.1%), and South American (8.9%). BMI was most strongly associated with AHI in South Americans (7.8% increase in AHI per 1 kg/m² increase in BMI; P < .0001) and most weakly in African Americans (1.9% increase in AHI per 1 kg/m² increase in BMI; P = .002). In Caucasians and South Americans, associations were stronger in males than females. Mallampati score differed between ethnicities but did not influence AHI differently across groups.

CONCLUSIONS

We demonstrate ethnic and sex variations in associations between obesity and OSA. For similar BMI increases, South American patients show greatest AHI increases compared to African Americans. Findings highlight the importance of considering ethnicity and sex in clinical assessments of OSA risk.

Diagnostic Accuracy of a Modified STOP-BANG Questionnaire with National Anthropometric Obesity Indexes

OBJECTIVES

Obstructive sleep apnea (OSA) is a very common sleep-related disorder and has many medical complications. Although the STOP-BANG questionnaire is an attractive screening tool because of high sensitivity, it lacks power in specificity. The aim of the present study was to evaluate and compare the diagnostic accuracy of standard STOP-BANG and a modified STOP-BANG questionnaire, using national cut-off values for neck circumference that determined OSA, in a sleep center population.

MATERIALS AND METHODS

One hundred eighty-five participants who were referred to the sleep-disordered breathing clinic were consecutively enrolled. We used 40 cm and 36 cm as the cut-off values for neck circumference, thus scoring patients accordingly and creating a modified STOP-BANG score with national anthropometric obesity indexes.

RESULTS

The median neck circumferences were 41 (39-44) cm, 40 (37-42) cm, and 43 (40-45) cm for total population, female gender, and male gender, respectively. The mean STOP-BANG score was 4.5±1.5, and the mean modified STOP-BANG score was 4.9±1.5. Discrimination of OSA measured by area under the curve for both questionnaires is comparable (p>0.05). Sensitivity to define OSA (apnea-hypopnea index (AHI)≥5) was 92.2% and 93.8% for original and modified STOP-BANG questionnaire, respectively. Sensitivity for moderate (AHI≥15) and severe OSA (AHI≥30) was identical for both questionnaires.

CONCLUSION

The STOP-BANG questionnaire has an excellent sensitivity, but modest specificity and adding national obesity indexes for neck circumference achieved similar results in terms of sensitivity and specificity with the original questionnaire.

Associations of variants In the hexokinase 1 and interleukin 18 receptor regions with oxyhemoglobin saturation during sleep

Sleep disordered breathing (SDB)-related overnight hypoxemia is associated with cardiometabolic disease and other comorbidities. Understanding the genetic bases for variations in nocturnal hypoxemia may help understand mechanisms influencing oxygenation and SDB-related mortality. We conducted genome-wide association tests across 10 cohorts and 4 populations to identify genetic variants associated with three correlated measures of overnight oxyhemoglobin saturation: average and minimum oxyhemoglobin saturation during sleep and the percent of sleep with oxyhemoglobin saturation under 90%. The discovery sample consisted of 8,326 individuals. Variants with p < 1 × 10(-6) were analyzed in a replication group of 14,410 individuals. We identified 3 significantly associated regions, including 2 regions in multi-ethnic analyses (2q12, 10q22). SNPs in the 2q12 region associated with minimum SpO2 (rs78136548 p = 2.70 × 10(-10)). SNPs at 10q22 were associated with all three traits including average SpO2 (rs72805692 p = 4.58 × 10(-8)). SNPs in both regions were associated in over 20,000 individuals and are supported by prior associations or functional evidence. Four additional significant regions were detected in secondary sex-stratified and combined discovery and replication analyses, including a region overlapping Reelin, a known marker of respiratory complex neurons.These are the first genome-wide significant findings reported for oxyhemoglobin saturation during sleep, a phenotype of high clinical interest. Our replicated associations with HK1 and IL18R1 suggest that variants in inflammatory pathways, such as the biologically-plausible NLRP3 inflammasome, may contribute to nocturnal hypoxemia.

Relationship between jaw-opening force and neck circumference in healthy older individuals

AIM

In recent years, the relationships of arm circumference and calf circumference with swallowing function have been reported. However, the efficacy of using the neck circumference, which is closer to the swallowing-related muscles, has never been verified. Jaw-opening force, an indicator of suprahyoid muscle strength, is known to be useful for screening for dysphagia. The aim of the present study was to identify the relationships between neck circumference and swallowing-related muscle strength, and to clarify the association between these variables in older individuals.

METHODS

A total of 104 healthy, independent older individuals, aged ≥65 years (36 men, 68 women, mean age 71.5 ± 4.5 years, range 65-83 years), participated in the study. Neck circumference, arm circumference, calf circumference, jaw-opening force and repetitive saliva swallowing test scores were measured. Multiple regression analysis was carried out to determine the relationship between neck circumference and jaw-opening force, between neck circumference and repetitive saliva swallowing test score, and to identify variables affecting jaw-opening force and neck circumference.

RESULTS

The participants' mean body mass index was 22.8 ± 2.9 (range 15.8-32.4). Sex and neck circumference, but not arm or calf circumference, were significant independent factors related to jaw-opening force. Independent factors affecting neck circumference were sex, body mass index, jaw-opening force and arm circumference, but not repetitive saliva swallowing test score.

CONCLUSIONS

In healthy older individuals, neck circumference was more strongly related to jaw-opening force than were arm or calf circumference. This suggested that neck circumference could be useful for evaluating swallowing-related muscle strength non-invasively and easily. Geriatr Gerontol Int 2019; 19: 330-334.

Gender differences in the application of anthropometric measures for evaluation of obstructive sleep apnea

This study aims to investigate anthropometric measures and their effectiveness as screening method for diagnosing obstructive sleep apnea (OSA) in each gender. We also evaluated which measures were associated with OSA in the adult population of a large metropolitan city, Sao Paulo, Brazil. 552 women and 450 men were submitted to polysomnography (PSG), and the anthropometric measurements as body mass index (BMI), waist-to-height ratio, neck and waist circumference were collected. The measurements were then compared with the OSA classification established by the PSG. In women, waist circumference and waist-to-height ratio were found to be the best predictor, while in men, the factors with great potential for identification varied according to severity of the disease, highlighting waist-to-height ratio, neck circumference and BMI had strongest association. The accuracy of the classification in relation to mild-to-severe OSA based on cut-off values of 92.5cm for waist circumference was greater than 72.9% in men, and 78.9% in women based on cut off values of 95cm. Regarding severe OSA, cut-off values of 116.1cm were greater than 91.3% accurate in the male population, and 95.1% in the female population with a cut-off value of 126.5cm. The study found waist circumference and waist-to-height ratio to be the best measure to assess sleep-disordered breathing in women. Waist-to-height ratio and neck circumferences were the best measures in men with mild OSA, but BMI was more closely associated with severe OSA. The present study identified the anthropometric variables with the highest risk for OSA and their respective cutoff value, according to gender.

Sex differences in mandibular repositioning device therapy effectiveness in patients with obstructive sleep apnea syndrome

Purpose

Mandibular repositioning devices (MRDs) are an effective treatment option for obstructive sleep apnea syndrome (OSAS), particularly in patients who refuse or cannot tolerate continuous positive airway pressure (CPAP). However, sex differences in the response to therapy and predictors of response are not clearly defined. This analysis of data from the long-term prospective ORCADES trial compared MRD efficacy in men and women with OSAS.

Methods

The ORCADES study included patients with newly diagnosed mild-to-moderate or severe OSAS who refused or were non-compliant with CPAP. MRD therapy was titrated over 3–6 months. The primary endpoint was treatment success (≥ 50% decrease in apnea-hypopnea index (AHI)). Complete response was defined using a range of AHI cut-off values (< 5/h, < 10/h, < 15/h).

Results

Overall treatment success rates were 89% in women and 76% in men (p = 0.019); corresponding rates in those with severe OSAS (AHI > 30/h) were 100% and 68% (p = 0.0015). In women vs. men, overall complete response rates at AHI cut-off values of < 5/h, <10/h, and < 15/h were 49 vs. 34% (p = 0.0052), 78 vs. 62% (p = 0.016), and 92 vs. 76% (p = 0.0032). On multivariate analysis, significant predictors of MRD treatment success were overbite and baseline apnea index in men, and neck circumference and no previous CPAP therapy in women. There were sex differences in the occurrence of side effects. Temporomandibular joint pain was the most common reason for stopping MRD therapy.

Conclusions

MRD therapy was effective in women with OSA of any severity, with significantly higher response rates compared with men especially in severe OSAS.

Trial registration

www.clinicaltrials.gov (NCT01326143).

A Population-Based Study of the Bidirectional Association Between Obstructive Sleep Apnea and Type 2 Diabetes in Three Prospective U.S. Cohorts

OBJECTIVE

Multiple lines of evidence support a complex relationship between obstructive sleep apnea (OSA) and diabetes. However, no population-based study has evaluated the potential bidirectional association between these two highly prevalent disorders.

RESEARCH DESIGN AND METHODS

We followed 146,519 participants from the Nurses' Health Study (NHS; 2002-2012), Nurses' Health Study II (NHSII; 1995-2013), and Health Professionals Follow-up Study (HPFS; 1996-2012) who were free of diabetes, cardiovascular disease, and cancer at baseline. Cox proportional hazards models were used to estimate hazard ratios (HRs) for developing diabetes according to OSA status. In parallel, we used similar approaches to estimate risk of developing OSA according to diabetes status among 151,194 participants free of OSA, cardiovascular disease, and cancer at baseline. In all three cohorts, diagnoses of diabetes and OSA were identified by validated self-reports.

RESULTS

Similar results were observed across the three cohorts. In the pooled analysis, 9,029 incident diabetes cases were identified during follow-up. After accounting for potential confounders, the HR (95% CI) for diabetes was 2.06 (1.86, 2.28) comparing those with versus without OSA. The association was attenuated but remained statistically significant after further adjusting for waist circumference and BMI (HR 1.37 [95% CI 1.24, 1.53]), with the highest diabetes risk observed for OSA concomitant with sleepiness (1.78 [1.13, 2.82]). In the second analysis, we documented 9,364 incident OSA cases during follow-up. Compared with those without diabetes, the multivariable HR (95% CI) for OSA was 1.53 (1.32, 1.77) in individuals with diabetes. Adjustment for BMI and waist circumference attenuated the association (1.08 [1.00, 1.16]); however, an increased risk was observed among those with diabetes who used insulin compared with those without diabetes (1.43 [1.11, 1.83]), particularly among women (1.60 [1.34, 1.89]).

CONCLUSIONS

OSA is independently associated with an increased risk of diabetes, whereas insulin-treated diabetes is independently associated with a higher risk of OSA, particularly in women. Clinical awareness of this bidirectional association may improve prevention and treatment of both diseases. Future research aimed at elucidating the mechanisms that underlie each association may identify novel intervention targets.

Simplifying the Screening of Obstructive Sleep Apnea With a 2-Item Model, No-Apnea: A Cross-Sectional Study

STUDY OBJECTIVES

To develop and validate a practical model for obstructive sleep apnea (OSA) screening in adults based on objectively assessed criteria, and then compare it with two widely used tools, namely STOP-BANG and NoSAS.

METHODS

This is a retrospective study of an existing database of consecutive outpatients who were referred for polysomnography for suspected sleep-disordered breathing by their primary care physicians. Area under the curve (AUC) and 2 × 2 contingency tables were employed to obtain the performance of the new instrument.

RESULTS

A total of 4,072 subjects were randomly allocated into two independent cohorts: one for derivation (n = 2,037) and one for validation (n = 2,035). A mnemonic model, named No-Apnea, with two variables (neck circumference and age) was developed (total score: 0-9 points). We used the cutoff ≥ 3 to classify patients at high risk of having OSA. OSA severity was categorized by apnea-hypopnea index (AHI): any OSA (AHI 5 ≥ events/h; OSA-5), moderate/ severe OSA (AHI 15 ≥ events/h; OSA-15); and severe OSA (AHI 30 ≥ events/h; OSA-30). In the derivation cohort, the AUCs for screening of OSA-5, OSA-15, and OSA-30 were: 0.784, 0.758, and 0.754; respectively. The rate of subjects correctly screened was 78.1%, 68.8%, and 54.4%, respectively for OSA-5, OSA-15, and OSA-30. Subsequently, the model was validated confirming its reproducibility. In both cohorts, No-Apnea discrimination was similar to STOP-BANG or NoSAS.

CONCLUSIONS

The No-Apnea, a 2-item model, appears to be a useful and practical tool for OSA screening, mainly when limited resources constrain referral evaluation. Despite its simplicity when compared to previously validated tools (STOP-BANG and NoSAS), the instrument exhibits similar performance characteristics.

The effect of surgical weight loss on obstructive sleep apnoea: A systematic review and meta-analysis

This review aimed to examine the relationship between surgical weight loss and obstructive sleep apnoea (OSA) severity (i.e., apnoea-hypopnoea index [AHI]), and how this relationship is altered by the various respiratory events scoring (RES) criteria used to derive the AHI. A systematic search of the literature was performed up to December 2017. Before-and-after studies were considered due to a paucity of randomised controlled trials (RCTs) available to be reviewed in isolation. Primary outcomes included pre- and post-surgery AHI and body mass index (BMI). Secondary outcomes included sleep study type and RES criteria. Meta-analysis was undertaken where possible. Overall, surgical weight loss resulted in reduction of BMI and AHI, however, OSA persisted at follow-up in the majority of subjects. There was high between-study heterogeneity which was largely attributable to baseline AHI and duration of follow-up when analysed using meta-regression. There was insufficient data to evaluate the impact of different RES criteria on OSA severity. Therefore, more RCTs are needed to verify these findings given the high degree of heterogeneity and future studies are strongly encouraged to report the RES criteria used to enable fair and uniform comparisons of the impact of any intervention on OSA severity.

Bariatric Surgery-Induced Resolution of Hypertension and Obstructive Sleep Apnea: Impact of Modulation of Body Fat, Ectopic Fat, Autonomic Nervous Activity, Inflammatory and Adipokine Profiles

BACKGROUND

Obesity-associated systemic hypertension (HTN) and obstructive sleep apnea (OSA) have multiple pathophysiological pathways including ectopic fat deposition, inflammation, altered adipokine profile, and increased sympathetic nervous activity. We characterized these potential mechanisms in severely obese patients with or without HTN and OSA. We also compared changes of these mechanisms at 12 months following biliopancreatic diversion with duodenal switch (BPD-DS) surgery according to HTN and OSA resolution.

METHODS

Sixty-two severely obese patients were evaluated at baseline and 12 months; 40 patients underwent BPD-DS. Blood samples, bioelectrical impedance analysis, computed tomography scan, and 24-h heart rate monitoring were performed. OSA have been determined with polysomnography and HTN with blood pressure measurement and medical file.

RESULTS

Patients with HTN (n = 35) and OSA (n = 32) were older men with higher ectopic fat deposition and lower parasympathetic nervous activity without difference in adipokines and inflammatory markers. Lower reduction in weight was observed in patients with unresolved HTN (-40.9 ± 3.3 kg vs. -55.6 ± 3.8 kg; p = 0.001) and OSA (-41.4 ± 10.7 kg vs. -51.0 ± 15.2 kg; p = 0.006). Visceral adipose tissue reduction was lower in patients with unresolved HTN (-171.0 ± 25.7 cm² vs. -274.5 ± 29.0 cm²; p = 0.001) in contrast to a trend for lower abdominal subcutaneous adipose tissue reduction in patients with unresolved OSA (-247.7 ± 91.5 cm² vs. -390.5 ± 109.1 cm²; p = 0.08). At 12 months, parasympathetic activity was lowest in unresolved HTN and OSA patients, without difference in adipokines and inflammatory biomarkers.

CONCLUSION

Lower ectopic fat mobilization, lower level of parasympathetic nervous activity, and lower subcutaneous adiposity mobilization may play a role in the pathophysiology of unresolved HTN and OSA following BPD-DS surgery.

Associations of obstructive sleep apnea with truncal skeletal muscle mass and density

Sarcopenia has been associated with several conditions relevant to obstructive sleep apnea (OSA), such as aging and obesity, but a direct relationship between OSA and skeletal muscle alterations has not been identified. This study investigated associations between computed tomography (CT)-measured skeletal muscle indices and OSA severity. Analyzed were 334 patients who underwent polysomnography to diagnose OSA. Lumbar skeletal muscles were assessed with CT for the skeletal muscle mass index (SMI, cross-sectional area, normalized for height squared) and skeletal muscle density (SMD, fat infiltration). The apnea-hypopnea index (AHI) correlated positively with the SMI and negatively with SMD in both men and women. The AHI was weakly associated with SMI only in men (β = 0.11, P = 0.017) after adjustment for the body mass index (BMI) (BMI: β = 0.61, P < 0.001 in men, β = 0.65, P < 0.001 in women). The association of AHI and SMD was not significant after adjustment for BMI (BMI: β = −0.42, P < 0.001 in men, β = −0.64, P < 0.001 in women). Severity of OSA correlated with increases in skeletal muscle mass rather than muscle depletion and skeletal muscle adiposity. These associations were limited compared with the stronger associations between obesity and skeletal muscles.