Obstructive sleep apnea and energy balance regulation: A systematic review

Circadian Biology in Obstructive Sleep Apnea-Associated Cardiovascular Disease

A dysregulated circadian system is independently associated with both Obstructive Sleep Apnea (OSA) and cardiovascular disease (CVD). OSA and CVD coexistence is often seen in patients with prolonged untreated OSA. However, the role of circadian dysregulation in their relationship is unclear. Half of the human genes, associated biological pathways, and physiological functions exhibit circadian rhythms, including blood pressure and heart rate regulation. Mechanisms related to circadian dysregulation and heart function are potentially involved in the coexistence of OSA and CVD. In this article, we provide a comprehensive overview of circadian dysregulation in OSA and associated CVD. We also discuss feasible animal models and new avenues for future research to understand their relationship. Oxygen-sensing pathways, inflammation, dysregulation of cardiovascular processes, oxidative stress, metabolic regulation, hormone signaling, and epigenetics are potential clock-regulated mechanisms connecting OSA and CVD.

Exploring the Association Between Triglyceride-Glucose Indices and Their Derivatives With Obstructive Sleep Apnea: Insights From the National Health and Nutrition Examination Survey

Background

Simple and affordable methods for evaluating Insulin Resistance (IR) have been suggested, such as the Triglyceride-Glucose (TyG) index and its variants, including the TyG-Body Mass Index (TyG-BMI), TyG-Waist Circumference (TyG-WC), and TyG-Waist-to-Height Ratio (TyG-WHtR). The aim of this study is to investigate the relationship between these TyG-related indices, which measure IR, and Obstructive Sleep Apnea (OSA).

Methods

This study analyzed NHANES data from 2007-2008, 2015-2016, and 2017-2020. TyG and its derivatives were evaluated as continuous and categorical variables in relation to OSA using multivariable logistic regression models. Subgroup analyses, dose-response relationships, and threshold effects were explored, and the diagnostic performance of TyG-related indices was assessed using AUC curves.

Results

The study included 8,374 participants. The fully adjusted Model 3 analysis (Note: Body Mass Index was not adjusted for TyG-BMI) of continuous variables showed a positive correlation between OSA and all four indices. All four TyG-related indicators showed statistically significant relationships with OSA when grouped into quartiles (TyG: AOR = 1.448, 95% CI: 1.260-1.663; TyG-BMI: AOR = 3.785, 95% CI: 3.319-4.317; TyG-WC: AOR = 2.089, 95% CI: 1.629-2.677; TyG-WHtR: AOR = 1.913, 95% CI: 1.548-2.363). Subgroup analysis revealed a stronger association of TyG-WHtR with OSA in the 41-59 age group (AOR = 1.459, 95% CI: 1.254-1.698) and the low-income group (AOR = 1.451, 95% CI: 1.241-1.698). TyG showed a linear relationship with OSA, while TyG-BMI, TyG-WC, and TyG-WHtR exhibited nonlinear relationships. The diagnostic capability was highest for TyG-WC, with an AUC of 0.647.

Conclusion

The study confirms strong associations between OSA and the TyG indices, particularly TyG-WC, which demonstrates significant predictive power for OSA risk. Future longitudinal studies are recommended to further investigate these associations and enhance OSA management in resource-constrained environments.

Body mass index mediates the association between plasma lipid concentrations and the prevalence of obstructive sleep apnea among US adults: a cross-sectional study

Background

The association between obstructive sleep apnea (OSA) and plasma lipid concentrations is not consistent. This study aimed to investigate the association of plasma lipid concentrations with the prevalence of OSA among US adults, with an additional examination of the mediating effect of body mass index (BMI).

Methods

This cross-sectional study included 8,086 individuals who participated in the National Health and Nutrition Examination Survey (NHANES), conducted from 2005 to 2008 and 2015-2018. Multivariable logistic regression analysis was conducted to compute the odds ratios (ORs) and 95% confidence intervals (CIs) for the association between plasma lipid concentrations and the prevalence of OSA. Additionally, subgroup analysis was used to explore the potential interactions. Generalized additive models (GAM) were constructed to evaluate the nonlinear relationships between lipid concentrations and OSA. Furthermore, mediation analysis was performed to assess the potential mediating role of BMI.

Results

In the fully adjusted model, when comparing the lowest quartile, the ORs for the prevalence of OSA among participants in the highest quartile were 1.367 (95% CI, 1.107-1.688) for triglyceride and 1.212 (95% CI, 1.004-1.462) for low-density lipoprotein cholesterol (LDL-C). However, total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) were not associated with OSA. Notably, the relationship between triglyceride and OSA differed in the subgroups of gender, race, and body mass index (BMI) (P for interaction <0.05). Furthermore, we discovered an inverted U-shaped association between triglyceride and OSA (inflection point: 0.813 mmol/L). Causal mediation analysis revealed that BMI significantly mediated the relationship between triglyceride and the prevalence of OSA.

Conclusions

This study revealed that an elevated level of triglyceride increased the prevalence of OSA, and this effect was potentially mediated through BMI. Lowering triglyceride concentration may help to reduce the prevalence of OSA.

Association between metabolic score for visceral fat and obstructive sleep apnea: a cross-sectional study

Background

Previous studies have established a connection between obesity and obstructive sleep apnea (OSA), novel surrogate markers of adipose accumulation may serve as more critical and reliable factors for consideration. Consequently, this study aims to explore and elucidate the correlation between metabolic score for visceral fat (METS-VF) and OSA.

Methods

In this cross-sectional study, the data from the National Health and Nutrition Examination Survey (NHANES) during the period from 2013 to 2020 were adopted. Through multivariate logistic regression, restricted cubic spline regression (RCS), subgroup analyses and sensitivity analyses, the correlation between METS-VF and OSA was explored.

Results

Among 8,284 subjects, 4,176 of them were categorized as having OSA. It was observed that the quartile range of METS-VF increased, with a notable rise in the prevalence of OSA (32.8% vs. 49.8% vs. 56.9% vs. 62.1%, p < 0.001). Logistic regression analyses showed a significant positive correlation between METS-VF and the risk of having OSA, even after accounting for potential confounders (OR = 2.436, 95% CI: 2.065, 2.874). Subgroup analyses further revealed a stronger correlation between OSA and METS-VF among subjects who were female, younger, and Mexican Americans. RCS regression identified a positive linear correlation, without threshold effects. Sensitivity analyses with stop breathing (OR = 2.283, 95%CI: 1.169, 3.070) or snoring (OR = 2.716, 95%CI: 2.273, 3.246) as outcomes reaffirmed the positive correlation with METS-VF.

Conclusion

Elevated METS-VF demonstrated a linear correlation with the increased incidence of OSA, suggesting the potential utility as a predictive index for OSA.

Association between sleep quality and duration during pregnancy and risk of gestational diabetes: A systematic review and meta-analysis

OBJECTIVE

Gestational diabetes mellitus (GDM) is associated with several adverse maternal and neonatal outcomes. Previous studies reported a link between altered sleep and risk of GDM. This systematic review aims to collate evidence on the association between impaired sleep quality and duration, and the risk of GDM.

METHODS

PubMed, Embase, Web of Science, and Scopus databases were searched up to January 20, 2024. Studies reporting the association between impaired sleep quality and duration and risk of GDM were included. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Random-effects meta-analysis was performed, and the results were reported as hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

19 studies were included. Meta-analysis revealed a significant increase in the risk of GDM in pregnant women with poor sleep quality (i.e. <5 PSQI) (HR: 1.50, 95% CI: 1.26 - 1.78, p < .001). Sleep duration of <7 h (HR: 1.56, 95% CI.: 1.20 - 2.01, p < .001), and >8 h (HR: 2.32, 95% CI.: 1.19 - 4.50, p = .01) were also associated with a significantly higher incidence of GDM.

CONCLUSION

Sleep quality and duration emerge as critical risk factors of GDM. Healthcare practitioners should consider targeted interventions to improve sleep hygiene as a potential measure for GDM prevention.

Contribution of glucose and glutamine to hypoxia-induced lipid synthesis decreases, while contribution of acetate increases, during 3T3-L1 differentiation

The molecular mechanisms linking obstructive sleep apnea syndrome (OSA) to obesity and the development of metabolic diseases are still poorly understood. The role of hypoxia (a characteristic feature of OSA) in excessive fat accumulation has been proposed. The present study investigated the possible effects of hypoxia (4% oxygen) on de novo lipogenesis by tracking the major carbon sources in differentiating 3T3-L1 adipocytes. Gas-permeable cultuware was employed to cultivate 3T3-L1 adipocytes in hypoxia (4%) for 7 or 14 days of differentiation. We investigated the contribution of glutamine, glucose or acetate using 13C or 14C labelled carbons to the newly synthesized lipid pool, changes in intracellular lipid content after inhibiting citrate- or acetate-dependent pathways and gene expression of involved key enzymes. The results demonstrate that, in differentiating adipocytes, hypoxia decreased the synthesis of lipids from glucose (44.1 ± 8.8 to 27.5 ± 3.0 pmol/mg of protein, p < 0.01) and partially decreased the contribution of glutamine metabolized through the reverse tricarboxylic acid cycle (4.6% ± 0.2-4.2% ± 0.1%, p < 0.01). Conversely, the contribution of acetate, a citrate- and mitochondria-independent source of carbons, increased upon hypoxia (356.5 ± 71.4 to 649.8 ± 117.5 pmol/mg of protein, p < 0.01). Further, inhibiting the citrate- or acetate-dependent pathways decreased the intracellular lipid content by 58% and 73%, respectively (p < 0.01) showing the importance of de novo lipogenesis in hypoxia-exposed adipocytes. Altogether, hypoxia modified the utilization of carbon sources, leading to alterations in de novo lipogenesis in differentiating adipocytes and increased intracellular lipid content.

Correlation between obstructive sleep apnea and weight-adjusted-waist index: a cross-sectional study

Background

Obesity is recognized as a prominent factor in the pathogenesis of obstructive sleep apnea (OSA). The weight-adjusted-waist index (WWI) has emerged as a novel metric for assessing adiposity. The study aimed to investigate the potential correlation between WWI and OSA.

Methods

In this study, a cross-sectional analysis was conducted on the data from the National Health and Nutrition Examination Survey (NHANES) during the period from 2013 to 2020. To examine the correlation between WWI and OSA, multivariate logistic regression, smooth curve fitting, subgroup analysis and receiver operating characteristic (ROC) curve were employed.

Results

Among the total 18,080 participants, 9,050 were categorized as having OSA. It was observed that as the quartile range of WWI increased, there was a gradual rise in the prevalence of OSA (37.4% vs. 50.3% vs. 55.1% vs. 57.5%, p < 0.001). Logistic regression analyses demonstrated a significant positive correlation between WWI and the risk of OSA, even after accounting for potential confounders (OR = 1.314, 95% = 1.223, 1.411). Subgroup analysis further revealed a stronger correlation between OSA and WWI among individuals with normal weight, those under 50 years old, and those engaging in moderate physical activities. Smooth curve fitting identified a positive non-linear correlation, with an inflection point at 11.678. ROC analysis indicated that WWI (AUC = 0.664) can serve as a more robust predictor for OSA compared to BMI and waist circumference.

Conclusion

This study provides evidence that elevated levels of WWI are correlated with an increased risk of OSA, indicating the potential utility as predictive indicators for OSA.

Causal Relationship Between Childhood Obesity and Sleep Apnea Syndrome: Bidirectional Two-Sample Mendelian Randomization Analysis

Background

Childhood obesity has become a global pandemic, leading to a range of diseases. Childhood obesity appears to be associated with an increased prevalence of sleep apnea syndrome. Sleep apnea is an inestimable risk factor for thrombosis, hypertension, cardiomyopathy and many other diseases. Therefore, exploring the relationship between childhood obesity and sleep apnea syndrome will help to understand the potential link between the two and provide research directions for future disease prevention and treatment. However, no studies have confirmed whether there is a causal relationship between childhood obesity and sleep apnea syndrome.

Methods

The IEU OpenGWAS project provided the GWAS-aggregated data for childhood obesity and sleep apnea syndrome. Inverse-variance weighted (IVW) was used as the main method to evaluate the causal relationship between childhood obesity and sleep apnea syndrome. Single nucleotide polymorphisms (SNPs) were regarded as instrumental variables, and the screening threshold was P <5.0×10-6. Leave-one-out method was performed to confirm the robustness of the results.

Results

IVW analysis confirmed a causal relationship between genetic susceptibility to childhood obesity and an increased risk of sleep apnea syndrome [odds ratio (OR)=1.12, 95% confidence interval (CI): 1.02-1.23, P=0.016]. However, two-sample MR results also showed no causal relationship between genetic susceptibility to sleep apnea syndrome and an increased risk of childhood obesity (OR=1.50, 95% CI: 0.95-2.38, P=0.083). The intercept of MR-Egger regression was close to 0, which implies that there are no confounding factors in the analysis to affect the results of two-sample MR analysis. The leave-one-out results show that the bidirectional two-sample MR analysis results were robust.

Conclusion

There is a causal relationship between genetic susceptibility to childhood obesity and increased risk of sleep apnea syndrome. People with a history of childhood obesity should pay more attention to physical examination to early prevention and management of sleep apnea syndrome.

The CORE syndrome: an overlap of severe asthma, obstructive sleep apnea, rhinosinusitis, and esophageal reflux

PURPOSE

Asthma, obstructive sleep apnea (OSA), rhinosinusitis, and esophageal reflux are conditions that may overlap, forming a syndrome known as CORE. Whenever clinical remission of severe asthma (SA) is not achieved, it is essential to investigate the presence of comorbidities, in particular the presence of OSA that may lead to the diagnosis of CORE syndrome.

METHODS

The study was conducted on naive patients with SA and concomitant rhinosinusitis and esophageal reflux, referred to our institute since 2018. Patients who did not experience clinical remission were investigated for OSA through a home sleep apnea test. Subsequently, for those diagnosed with OSA, continuous positive airway pressure (CPAP) was proposed and was re-evaluated after 12 months.

RESULTS

Six patients with CORE syndrome were enrolled. The mean apnea-hypopnea index (AHI) was 33.25 ± 20.13 events/h, oxygen desaturation index (ODI) was 28.95 ± 19.95 events/h, and time in bed with SaO2 < 90% (T90) was 26.40 ± 27.22% for which continuous positive airway pressure (CPAP) treatment was proposed but only 3 out of 6 patients accepted. After 12 months, all CPAP-treated patients manifested a significant reduction in daytime sleepiness (ESS score was 6.33 ± 3.8), an improvement in ACT score (+ 8 (+ 32%), + 9 (+ 36%), and + 14 (+ 56%) points), a discontinuation of oral corticosteroids (OCS), an absence of exacerbations, and an improvement of lung function leading to clinical remission of asthma.

CONCLUSION

Whenever facing SA patients, non-responders to therapy, it is important to suspect the presence of CORE syndrome; in particular, the detection and subsequent treatment of OSA would seem to improve the outcome of such patients.

The benefits of hypoglycemic therapy for patients with obstructive sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) is often associated with glycemic abnormalities. This study is conducted to investigate the effects of hypoglycemic therapy on OSA-related indicators.

METHOD

We systematically searched Web of Science, PubMed, Embase, and the Cochrane Library for articles on OSA patients receiving any hypoglycemic drugs, published until December 25, 2022. Seven original studies were finally included. The proposal was registered with PROSPERO (CRD42022351206).

RESULTS

In summary, in addition to reduced glycosylated hemoglobin A1c (HbA1c), we found that hypoglycemic treatment can lower the apnea-hypopnea index (AHI) by 7.07/h (p = 0.0001). Although long-term treatment (> 12 weeks) achieved a more significant reduction in HbA1c (- 1.57% vs. - 0.30%) compared to short-term treatment (≤ 12 weeks), there was no significant difference between the two in terms of AHI (intergroup p-value = 0.27). We also found that patients using sodium glucose cotransporter 2 inhibitors (SGLT2i) experienced a greater reduction in AHI (- 11.00/h, p < 0.00001). Additionally, hypoglycemic treatment also showed certain improvements in related indicators like Epworth Sleepiness Scale, body mass index, and blood pressure.

CONCLUSIONS

Our results affirm the benefits of hypoglycemic treatment for OSA patients and highlight the notable effect of SGLT2i. Further researches are needed to help doctors gain a comprehensive understanding of the interaction between OSA and glycemic abnormalities.

Modelling metabolic performance in paediatric obstructive sleep disordered breathing: A case-control study

Paediatric obstructive sleep disordered breathing (OSDB) has a considerable impact on cardiovascular physiology, but the consequences on children's basal metabolism and response to exercise are far from being known. The objective was to propose model estimations for paediatric OSDB metabolism at rest and during exercise. A retrospective case-control analysis of data from children submitted to otorhinolaryngology surgery was performed. The heart rate (HR) was measured, while oxygen consumption (VO2) and energy expenditure (EE) at rest and during exercise were obtained using predictive equations. The results for the patients with OSDB were compared with controls. A total of 1256 children were included. A total of 449 (35.7%) had OSDB. The patients with OSDB showed a significantly higher resting heart rate (94.55 ± 15.061 bpm in OSDB vs. 92.41 ± 15.332 bpm in no-OSDB, p = 0.041). The children with OSDB showed a higher VO2 at rest (13.49 ± 6.02 mL min-1kg-1 in OSDB vs. 11.55 ± 6.83 mL min-1kg-1 in no-OSDB, p = 0.004) and a higher EE at rest (67.5 ± 30.10 cal min-1kg-1 in OSDB vs. 57.8 + 34.15 cal min-1kg-1 in no-OSDB, p = 0.004). At maximal exercise, patients with OSDB showed a lower VO2max (33.25 ± 5.82 mL min-1kg-1 in OSDB vs. 34.28 ± 6.71 in no-OSDB, p = 0.008) and a lower EE (166.3 ± 29.11 cal min-1kg-1 in OSDB vs. 171.4 ± 33.53 cal min-1kg-1 in no-OSDB, p = 0.008). The VO2/EE increment with exercise (Δ VO2 and Δ EE) was lower in OSDB for all exercise intensities (p = 0.009). This model unveils the effect of paediatric OSDB on resting and exercise metabolism. Our findings support the higher basal metabolic rates, poorer fitness performance, and cardiovascular impairment found in children with OSDB.

Association between obstructive sleep apnea and visceral adiposity index and lipid accumulation product: NHANES 2015-2018

BACKGROUND

Obesity refers to a significant contributor to the development of obstructive sleep apnea (OSA). Early prediction of OSA usually leads to better treatment outcomes, and this study aims to employ novel metabolic markers, visceral adiposity index (VAI), and lipid accumulation product (LAP) to evaluate the relationship to OSA.

METHODS

The data used in the current cross-sectional investigation are from the National Health and Nutrition Examination Survey (NHANES), which was carried out between 2015 and 2018. To examine the correlation between LAP and VAI levels and OSA, multivariate logistic regression analysis was adopted. In addition, various analytical methods were applied, including subgroup analysis, smooth curve fitting, and threshold effect analysis.

RESULTS

Among totally 3932 participants, 1934 were included in the OSA group. The median (Q1-Q3) values of LAP and VAI for the participants were 40.25 (21.51-68.26) and 1.27 (0.75-2.21), respectively. Logistic regression studies indicated a positive correlation between LAP, VAI, and OSA risk after adjusting for potential confounding variables. Subgroup analysis revealed a stronger correlation between LAP, VAI levels, and OSA among individuals aged < 60 years. Through smooth curve fitting, specific saturation effects of LAP, VAI, and BMD were identified, with inflection points at 65.684 and 0.428, respectively.

CONCLUSION

This study demonstrates that elevated levels of LAP and VAI increase the risk of OSA, suggesting their potential as predictive markers for OSA and advocating for dietary and exercise interventions to mitigate OSA risk in individuals with high LAP and VAI levels.

The Influence of CPAP Therapy on Basal Metabolic Rate and Physical Activity in Obese Patients with Obstructive Sleep Apnea

BACKGROUND

Energy balance in Obstructive Sleep Apnea (OSA), a disease closely related to obesity, is disturbed, and physical activity levels are impaired. The role of Continuous Positive Airway Pressure treatment (CPAP) in alleviating the disruptions mentioned above is questioned. The objective of this study is to explore changes in energy expenditure (EE) and physical activity (PA) in obese patients with OSA after CPAP treatment.

METHODS

An assessment of Basal Metabolic Rate (BMR) via indirect calorimetry (IC) was performed on 24 obese patients (male in the majority (87.5%), mean age of 52.4 ± 9.8 years), newly diagnosed with moderate-severe OSA by polysomnography, at 4-time points: at baseline, at CPAP titration, at the 1-month and the 3-month follow up. Physical activity levels were subjectively estimated using the International Questionnaire of Physical Activity (IPAQ) before and after 3 months of adherent CPAP application.

RESULTS

BMR significantly decreased after CPAP treatment (1926 ± 537.8 kcal/d at baseline, 1790 ± 493.7 kcal/d at CPAP initiation, 1680.3 ± 600.8 kcal/d at 1 month, and 1581.3 ± 478.9 kcal/d at 3 months follow up (p < 0.001)). No significant changes in IPAQ were observed over time: baseline median IPAQ: 3894 (1487.5-11,755.5) total MET·min·wk-1, 3-month median IPAQ: 3900 (1512-11,824.5) total MET·min·wk-1.

CONCLUSIONS

CPAP has an appreciable time effect on the BMR of obese patients with moderate-severe OSA. However, this change is not accompanied by a significant increase in physical activity levels.

Sleep quality, sleep apnea, and metabolic health in children treated with adenotonsillectomy

PURPOSE

The aim of this study was to determine if cardiopulmonary coupling (CPC) calculated sleep quality (SQI) may predict changes in metabolic health in children treated with early adenotonsillectomy (eAT) for obstructive sleep apnea (OSA).

METHODS

Secondary analysis of the Childhood Adenotonsillectomy Trial (CHAT) was performed including children 5.0-9.9 years with OSA assigned to eAT. The cohort was stratified based on SQI and AHI to evaluate (1) response to eAT in children with high sleep quality (SQI ≥ 75) and mild-OSA, AHI < 5.0 (group1) and children with moderate-OSA AHI ≥ 5.0 or SQI < 75 (group2) at baseline and (2) effect of eAT therapy on metabolic health, GroupRemission (AHI < 1.0, SQI ≥ 75) compared to GroupResidual.

RESULTS

At baseline group2 (n=124) had higher average heart rate during sleep (AHRSleep), 87 vs. 81 beats/minute (p < 0.001) compared to group1 (n=72). After surgery, group2 on average had less increase in BMI z-score 0.13 vs. 0.27, (p = 0.025), improved their SQI + 2.06 compared to decline - 3.75 in group1, (p = 0.015), decreased AHRSleep-- 2.90 vs. - 0.34 (p = 0.025) and AHI - 5.00 vs. - 0.36 (p = 0.002). GroupRemission was younger 6.59 vs. 7.41; p < 0.001; with lower BMI z-score 0.90 vs. 1.34; p = 0.021; AHRSleep 80.60 vs. 83.50; p = 0.032; fasting insulin (µIU/ml) 7.54 vs. 12.58; p = 0.017 and glucose (mmol/L) 4.45 vs. 4.60; p = 0.049, with better lipid metabolism though not statistically significantly, low-density-lipoprotein 90.26 mg/dL vs. 97.94; p = 0.081 and cholesterol 154.66 mg/dL vs. 164.36; p = 0.076.

CONCLUSION

The results may indicate that children with mild-OSA and high-SQI may be less likely to benefit from eAT than children with moderate-OSA. To improve metabolic health, successfully treating both AHI and SQI is likely needed. CPC-calculated SQI may have a role to identify children less likely to benefit from eAT and to evaluate success of therapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00560859.

Examining the relationship between obstructive sleep apnoea and eating behaviours and attitudes: A systematic review

BACKGROUND

Between 60 and 90% of adults with OSA are reported as overweight. The co-existence of obesity and OSA can greatly increase an individual's risk of type 2 diabetes, metabolic syndrome and cardiovascular disease. To better understand this relationship between OSA and weight, this review aimed to investigate if there is evidence of certain eating behaviours or eating attitudes that might be found in adults living with OSA.

METHODS

We searched four databases (MEDLINE, Embase, PsycInfo and Web of Science) on January 17th, 2022, to identify studies assessing the association between eating patterns and OSA in adults. Twenty-one studies met the inclusion criteria. A narrative synthesis was conducted on the included studies, following the vote-counting method.

RESULTS

There is preliminary evidence that the time of day when calories are consumed is associated with lower OSA severity. No other clear patterns of eating behaviours or attitudes were identified however this may be due to disparity within research studies and their reported results.

CONCLUSION

Further research is needed to examine the relationship between eating times and OSA severity. We recommend standardising the approach to examining the eating patterns of those living with OSA and the relationship that this might have on OSA symptoms as well as looking at attitudes towards food in this population. This may prove helpful in providing a better understanding of the relationship between OSA and persons with overweight and help in future intervention development.

Evaluation of Blood Levels of Omentin-1 and Orexin-A in Adults with Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

Background and objective: Obstructive sleep apnea (OSA) can be related to changes in the levels of adipokines and neuropeptides, which in turn may affect the energy balance components of neuronal cells. Herein, a systematic review and meta-analysis checked the changes in serum/plasma levels of omentin-1 (OM-1: an adipokine) and orexin-A (OXA: a neuropeptide) in adults (age > 18 years old) with OSA (aOSA) compared to controls. Materials and methods: Four databases (Cochrane Library, PubMed, Web of Science, and Scopus) were systematically searched until 14 November 2022, without any restrictions. The Joanna Briggs Institute (JBI) critical appraisal checklist adapted for case−control studies was used to assess the quality of the papers. The effect sizes were extracted using the Review Manager 5.3 software for the blood levels of OM-1 and OXA in aOSA compared with controls. Results: Thirteen articles, with six studies for OM-1 levels and eight for OXA levels, were included. The pooled standardized mean differences were −0.85 (95% confidence interval (CI): −2.19, 0.48; p = 0.21; I2 = 98%) and −0.20 (95%CI: −1.16, 0.76; p = 0.68; I2 = 96%) for OM-1 and OXA levels, respectively. Among the studies reporting OM-1, five were high and one was moderate quality. Among the studies reporting OXA, six were moderate, one was high, and one was low quality. Based on the trial sequential analysis, more participants are needed to confirm the pooled results of the analyses of blood levels of OM-1 and OXA. In addition, the radial plot showed outliers as significant factors for high heterogeneity. Conclusions: The main findings indicated a lack of association between the blood levels of OM-1 and OXA and OSA risk. Therefore, OM-1 and OXA did not appear to be suitable biomarkers for the diagnosis and development of OSA.

Effect of Continuous Positive Airway Pressure on Changes of Plasma/Serum Ghrelin and Evaluation of These Changes between Adults with Obstructive Sleep Apnea and Controls: A Meta-Analysis

BACKGROUND AND OBJECTIVE

Obstructive sleep apnea (OSA) can be related to high ghrelin hormone levels that may encourage additional energy intake. Herein, a new systematic review and meta-analysis were performed to check the changes in serum/plasma levels of ghrelin in adults with OSA compared to controls, as well as before compared after continuous positive airway pressure (CPAP) therapy in adults with OSA.

MATERIALS AND METHODS

Four main databases were systematically and comprehensively searched until 17 October 2022, without any restrictions. For assessing the quality, we used the Joanna Briggs Institute (JBI) critical appraisal checklist adapted for case-control studies and the National Institutes of Health (NIH) quality assessment tool for before-after studies. The effect sizes were extracted by the Review Manager 5.3 software for the blood of ghrelin in adults with OSA compared with controls, as well as before and after CPAP therapy.

RESULTS

Fifteen articles involving thirteen studies for case-control studies and nine articles for before-after studies were included. The pooled standardized mean differences were 0.30 (95% confidence interval (CI): -0.02, 0.61; p = 0.07; I² = 80%) and 0.10 (95% CI: -0.08, 0.27; p = 0.27; I² = 42%) for case-control and before-after studies, respectively. For thirteen case-control studies, nine had moderate and four high qualities, whereas for nine before-after studies, five had good and four fair qualities. Based on the trial sequential analysis, more studies are needed to confirm the pooled results of the analyses of blood ghrelin levels in case-control and before-after studies. In addition, the radial plot showed outliers for the analysis of case-control studies that they were significant factors for high heterogeneity.

CONCLUSIONS

The findings of the present meta-analysis recommended that the blood levels of ghrelin had no significant difference in the adults with OSA compared with the controls, nor did they have significant difference in adults with OSA before compared with after CPAP therapy. The present findings need to be confirmed in additional studies with more cases and higher qualities.

Impact of adenotonsillectomy on growth trajectories in preschool children with mild-moderate obstructive sleep apnea

STUDY OBJECTIVES

Adenotonsillectomy (AT) forms part of first-line management for pediatric obstructive sleep apnea. In nonrandomized studies of preschool-aged children, postoperative weight gain has been seen following AT, raising concerns regarding later obesity. Using longitudinal data from a multicenter randomized controlled trial, we assessed the impact of AT on growth trajectories in preschool-aged children with mild-moderate obstructive sleep apnea.

METHODS

A total of 190 children (aged 3-5 years) with obstructive apnea-hypopnea index ≤ 10 events/h were randomly assigned to early (within 2 months) or routine (12-month wait) AT. Anthropometry and polysomnography were performed at baseline, 12-month, and 24-month time points for 126 children. Baseline characteristics were compared using a Mann-Whitney or t test for continuous variables and Fisher's exact test for categorical variables. Longitudinal data underwent linear mixed modeling.

RESULTS

For body mass index (BMI) z-score there was a significant increase in the early surgery group between 0 and 12 months (0.4, 95% confidence interval 0.1-0.8) but not from 12-24 months. For the routine surgery group there was an identical significant BMI z-score increase in the first 12 months following surgery, ie, between 12- and 24-month time points (0.45, 95% confidence interval 0.1-0.8) but not from 0-12 months (preoperative time). Final BMI z-score was similar between groups. Findings for weight-for-age z-score were similar to the findings for BMI z-score. Height-for-age z-score was not significantly different between different time points or intervention groups.

CONCLUSIONS

This study provides randomized controlled trial evidence of notable, but time-limited, increase in the BMI and weight of preschool children with mild-moderate obstructive sleep apnea in the months immediately following AT.

CLINICAL TRIAL REGISTRATION

Registry: Australian New Zealand Clinical Trials Registry; Name: POSTA Child Study (Preschool Obstructive Sleep Apnea Tonsillectomy Adenoidectomy Study); URL: https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=336273&isReview=true; Identifier: ACTRN12611000021976.

CITATION

Kevat A, Bernard A, Harris M-A, et al. Impact of adenotonsillectomy on growth trajectories in preschool children with mild-moderate obstructive sleep apnea. J Clin Sleep Med. 2023;19(1):55-62.

Effects of solriamfetol treatment on body weight in participants with obstructive sleep apnea or narcolepsy

OBJECTIVES

This analysis characterized changes in weight in participants with obstructive sleep apnea (OSA) or narcolepsy treated with solriamfetol (Sunosi™) 37.5 (OSA only), 75, 150, or 300 mg/d.

METHODS

In two 12-week, randomized, placebo-controlled trials and one 1-year open-label extension study, changes in weight were evaluated from baseline to end of study (week 12 or week 40 of the open-label extension [after up to 52 weeks of solriamfetol treatment]) in participants with OSA or narcolepsy.

RESULTS

After 12 weeks of solriamfetol treatment, median percent change in weight from baseline across all solriamfetol doses was -0.84%, compared with 0.54% for placebo, in participants with OSA; and -0.07%, compared with 3.08% for placebo, in participants with narcolepsy. After up to 52 weeks of solriamfetol treatment, overall median percent change in weight from baseline was -1.76%, which showed a dose-dependent pattern (75 mg, 0.57%; 150 mg, -1.2%; 300 mg, -2.5%). Results were similar in subgroups of participants with OSA or narcolepsy, with overall median percent changes in weight of -2.2% and -1.1%, respectively. After up to 52 weeks of solriamfetol treatment, the percentage of participants with weight loss ≥5% relative to baseline was 25.7% overall and increased in a dose-dependent manner (75 mg, 4.5%; 150 mg, 17.3%; 300 mg, 32.4%). Results were similar among subgroups of participants with OSA or narcolepsy, with 26.4% and 24.2% of participants experiencing weight loss ≥5%, respectively. No weight-related treatment-emergent adverse events were serious.

CONCLUSIONS

Solriamfetol treatment was associated with decreases in body weight in a dose-related manner.

Nutritional and Metabolic Imbalance in Keratoconus

Keratoconus (KC) is a progressive corneal degeneration characterized by structural changes consisting of progressive thinning and steepening of the cornea. These alterations result in biomechanical weakening and, clinically, in vision loss. While the etiology of KC has been the object of study for over a century, no single agent has been found. Recent reviews suggest that KC is a multifactorial disease that is associated with a wide variety of genetic and environmental factors. While KC is typically considered a disease of the cornea, associations with systemic conditions have been well described over the years. In particular, nutritional and metabolic imbalance, such as the redox status, hormones, metabolites, and micronutrients (vitamins and metal ions), can deeply influence KC initiation and progression. In this paper, we comprehensively review the different nutritional (vitamins and minerals) and metabolic (hormones and metabolites) factors that are altered in KC, discussing their possible implication in the pathophysiology of the disease.

Leptin: A Potential Link Between Obstructive Sleep Apnea and Obesity

Chronic intermittent hypoxia (CIH), a pathophysiological manifestation of obstructive sleep apnea (OSA), is strongly correlated with obesity, as patients with the disease experience weight gain while exhibiting elevated plasma levels of leptin. This study was done to determine whether a relationship may exist between CIH and obesity, and body energy balance and leptin signaling during CIH. Sprague-Dawley rats were exposed to 96 days of CIH or normoxic control conditions, and were assessed for measures of body weight, food and water intake, and food conversion efficiency. At the completion of the study leptin sensitivity, locomotor activity, fat pad mass and plasma leptin levels were determined within each group. Additionally, the hypothalamic arcuate nucleus (ARC) was isolated and assessed for changes in the expression of proteins associated with leptin receptor signaling. CIH animals were found to have reduced locomotor activity and food conversion efficiency. Additionally, the CIH group had increased food and water intake over the study period and had a higher body weight compared to normoxic controls at the end of the study. Basal plasma concentrations of leptin were significantly elevated in CIH exposed animals. To test whether a resistance to leptin may have occurred in the CIH animals due to the elevated plasma levels of leptin, an acute exogenous (ip) leptin (0.04 mg/kg carrier-free recombinant rat leptin) injection was administered to the normoxic and CIH exposed animals. Leptin injections into the normoxic controls reduced their food intake, whereas CIH animals did not alter their food intake compared to vehicle injected CIH animals. Within ARC, CIH animals had reduced protein expression of the short form of the obese (leptin) receptor (isoform OBR₁₀₀) and showed a trend toward an elevated protein expression of the long form of obese (leptin) receptor (OBRb). In addition, pro-opiomelanocortin (POMC) protein expression was reduced, but increased expression of the phosphorylated extracellular-signal-regulated kinase 1/2 (pERK1/2) and of the suppressor of cytokine signaling 3 (SOCS3) proteins was observed in the CIH group, with little change in phosphorylated signal transducer and activator of transcription 3 (pSTAT3). Taken together, these data suggest that long-term exposure to CIH, as seen in obstructive sleep apnea, may contribute to a state of leptin resistance promoting an increase in body weight.

The Causal Effects of Lipid Profiles on Sleep Apnea

Introduction

Observational studies have suggested that lipid profiles were associated with risk of sleep apnea (SA). However, the specific lipid types and whether this relationship has a causal effect are uncertain. This study conducted two-sample Mendelian randomization (MR) and multivariable Mendelian randomization (MVMR) to investigate the potential causal relationship between lipid profiles and risk of SA.

Materials and Methods

We used the largest genome-wide association study (GWAS) on European participants on the UK Biobank. After a rigorous single nucleotide polymorphism screening process to remove confounding effects, we performed MR and MVMR to explore the causal relationship between lipid profiles and SA risk.

Results

Both MR and MVMR showed causal effects of increased triglyceride on SA risk [MR: per 10 units, odds ratio (OR): 1.0156; 95% CI: 1.0057-1.0257; P value = 0.002; MVMR: per 10 units, OR: 1.0229; 95% CI: 1.0051-1.0411; P value = 0.011]. The sensitivity analysis including Cochran's Q test, MR-Egger intercept, and MR pleiotropy residual sum and outlier (MR-PRESSO) test indicated that our findings were robust. The causal effects of triglyceride on SA did not change after adjusting for potential confounders (obesity, age, sex, and airway obstruction).

Conclusion

Genetically increased triglyceride levels have independent causal effects on risk of sleep apnea without the confounding effects of obesity, suggesting that lowering triglyceride concentrations may help to reduce the risk of sleep apnea.

Anorexigenic Effects of Intermittent Hypoxia on the Gut-Brain Axis in Sleep Apnea Syndrome

Sleep apnea syndrome (SAS) is a breathing disorder characterized by recurrent episodes of upper-airway collapse, resulting in intermittent hypoxia (IH) during sleep. Experimental studies with animals and cellular models have indicated that IH leads to attenuation of glucose-induced insulin secretion from pancreatic β cells and to enhancement of insulin resistance in peripheral tissues and cells, such as the liver (hepatocytes), adipose tissue (adipocytes), and skeletal muscles (myocytes), both of which could lead to obesity. Although obesity is widely recognized as a major factor in SAS, it is controversial whether the development of SAS could contribute directly to obesity, and the effect of IH on the expression of appetite regulatory genes remains elusive. Appetite is regulated appropriately by both the hypothalamus and the gut as a gut-brain axis driven by differential neural and hormonal signals. In this review, we summarized the recent epidemiological findings on the relationship between SAS and feeding behavior and focused on the anorexigenic effects of IH on the gut-brain axis by the IH-induced up-regulation of proopiomelanocortin and cocaine- and amphetamine-regulated transcript in neuronal cells and the IH-induced up-regulation of peptide YY, glucagon-like peptide-1 and neurotensin in enteroendocrine cells and their molecular mechanisms.

The timing of intermittent hypoxia differentially affects macronutrient intake and energy substrate utilization in mice

Sleep apnea is a common sleep disorder characterized by periodic breathing cessation and intermittent hypoxia (IH). Although previous studies have demonstrated that IH alone can influence metabolic outcomes such as body weight, it remains unclear how the timing of IH can specifically affect these outcomes. Here, we examine how pairing 10-h periods of IH to either the animals' resting phase (e.g., IH during the day) or active phase (e.g., IH during the night) differentially affects body weight, macronutrient selection, energy expenditure, respiratory exchange rate, and glucose tolerance. We find that in contrast to mice exposed to IH during the night, mice exposed to IH during the day preferentially decrease their carbohydrate intake and switch to fat metabolism. Moreover, when the IH stimulus was removed, mice that had been exposed to day IH continued to eat a minimal amount of carbohydrates and consumed a higher percentage of kilocalorie from fat for at least 5 days. These data demonstrate that food choice and substrate utilization are secondary to the timing of IH but not IH itself. Taken together, these data have key clinical implications for individuals with sleep apnea and particularly those who are also experiencing circadian disruption such as night-shift workers.NEW & NOTEWORTHY Pairing repeated hypoxic episodes to a mouse's resting phase during the day preferentially decreases carbohydrate intake and results in a switch to metabolic fat oxidation. These data indicate that the timing of intermittent hypoxia should be considered when calculating sleep apnea's effects on metabolic outcomes.

Changes in energy metabolism and respiration in different tracheal narrowing in rats

Why obstructive sleep apnea (OSA) treatment does not completely restore healthy metabolic physiology is unclear. In rats, the need for respiratory homeostasis maintenance following airway obstruction (AO) is associated with a loss of thermoregulation and abnormal metabolic physiology that persists following successful obstruction removal. Here, we explored the effect of two different types of tracheal narrowing, i.e., AO and mild airway obstruction (mAO), and its removal on respiratory homeostasis and metabolic physiology. We show that after ten weeks, mAO vs. AO consumes sufficient energy that is required to maintain respiratory homeostasis and thermoregulation. Obstruction removal was associated with largely irreversible increased feeding associated with elevated serum ghrelin, hypothalamic growth hormone secretagogue receptor 1a, and a phosphorylated Akt/Akt ratio, despite normalization of breathing and energy requirements. Our study supports the need for lifestyle eating behavior management, in addition to endocrine support, in order to attain healthy metabolic physiology in OSA patients.

Association of Sodium with Obstructive Sleep Apnea. The ELSA-Brasil Study

Rationale: Excessive sodium may have a role in the pathogenesis of obstructive sleep apnea (OSA) for patients with hypervolemic conditions, but it is unclear whether this is valid for all patients with OSA, including those with no significant comorbidities.Objectives: To test the association of urinary sodium and OSA in a large sample of participants from the ELSA-Brasil (Estudo Longitudinal de Saúde do Adulto-Brasil) Study. In addition, we stratified the analysis participants according to the presence of hypertension.Methods: In this cross-sectional study, OSA was defined by an apnea-hypopnea index ≥15 events/h. A validated 12-hour urine collection as representative of the 24-hour period was obtained from all participants to measure sodium excretion. We performed a logistic regression analysis to test the association of urinary sodium excretion with OSA (dependent variable) adjusting for age, sex, race and income, glomerular filtration rate, diabetes, physical activity, and antihypertensive classes related to sodium excretion. To address potential residual factors that may influence sodium excretion, we performed additional analysis replacing sodium excretion for salt intake (food frequency questionnaire) using the same models.Results: We studied 1,946 participants (age 49 ± 8 yr; 43.4% men). A third of them had OSA. Compared with those with no OSA, participants with OSA presented with higher sodium excretion (1.66 [1.19-2.29] vs. 1.99 [1.44-2.69] g/12 h; P < 0.001). After adjustments for confounding factors, we found no overall significant associations of sodium excretion with OSA (odds ratio [OR], 1.09; 95% confidence interval [CI], 0.97-1.23; P = 0.150). Regardless of the OSA status, the sodium excretion was higher in hypertensive than in normotensive participants (1.93 [1.35-2.64] vs. 1.71 [1.22-2.37] g/12 h). An independent association of sodium excretion with OSA was observed in patients with hypertension only (OR, 1.326; 95% CI, 1.067-1.648; P = 0.011), but the interaction of urinary sodium with hypertension was not significant (P = 0.37). The analysis of salt intake revealed consistent findings.Conclusions: The potential role of sodium in the pathogenesis of OSA seems to be modest and limited for those with higher salt intake and, consequently, higher fluid retention such as observed in patients with hypertension.

Predictors of weight loss in obese patients with obstructive sleep apnea

PURPOSE

Consistent predictors of weight loss outcomes with very low-energy diets (VLEDs) in obstructive sleep apnea (OSA) have not been identified. This study aimed to identify variables predictive of weight loss success in obese patients with OSA undertaking an intensive weight loss programme.

METHODS

We analysed biological, psychological, and behavioural variables as potential predictors of weight loss in obese patients with OSA after a 2-month VLED followed by one of two 10-month weight loss maintenance diets. Actigraphy, in-lab polysomnography, urinary catecholamines, and various psychological and behavioural variables were measured at baseline, 2, and 12 months. Spearman's correlations analysed baseline variables with 2-month weight loss, and 2-month variables with 2-12 month-weight change.

RESULTS

Forty-two patients completed the VLED and thirty-eight completed the maintenance diets. Actigraphy data revealed that late bedtime (r_s =  - 0.45, p =  < 0.01) was correlated with 2-month weight loss. The change in the time that participants got out of bed (rise-time) from baseline to two months was also correlated with 2-month weight loss (r_s = 0.36, p = 0.03). The Impact of Weight on Quality of Life-Lite questionnaire (IWQOL) Public Distress domain (r_s =  - 0.54, p =  < 0.01) and total (r_s =  - 0.38, p = 0.02) scores were correlated with weight loss maintenance from 2 to 12 months.

CONCLUSIONS

Results from this small patient sample reveal correlations between actigraphy characteristics and weight loss in obese patients with OSA. We suggest the IWQOL may also be a useful clinical tool to identify OSA patients at risk of weight regain after initial weight loss.

CLINICAL TRIAL REGISTRATION

This clinical trial was prospectively registered on 18/02/2013 with the Australia and New Zealand Clinical Trials Registry (ACTRN12613000191796).

PUBLIC REGISTRY TITLE

Sleep, Lifestyle, Energy, Eating, Exercise Program for the management of sleep apnea patients indicated for weight loss treatment: A randomised, controlled pilot study. URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=363680.

Obstructive sleep apnea and incidence of malignant tumors: a meta-analysis

OBJECTIVES

This paper assessed the connection between obstructive sleep apnea (OSA) and the incidence of malignant tumors.

METHODS

PubMed, Cochrane, Scopus, Health Source Nursing Academic Edition, EMBASE, and Web of Sciences were searched until the date of July 25, 2020. The analysis included an assessment of the overall incidence of OSA malignancies, the incidence of OSA malignancies by age and gender, and the incidence of different types of malignancies in patients with OSA. The total rate and the corresponding 95% confidence interval (CI) of the incidence of malignant tumors in patients with OSA were calculated. Patients with OSA were classified according to age, gender, and different types of malignant tumors for meta-analysis.

RESULTS

A total of 12 studies involving 862,820 participants were included in this meta-analysis. Random effect model analysis showed that the total incidence of malignant tumors in patients with OSA was 0.046% (95% CI: 0.027-0.065, P < 0.001), higher than that of malignant tumors in the general population. According to the analytical results classified by gender, the incidence of malignant tumor in female patients with OSA was 4.0% (95% CI: 0.014-0.066), higher than that in male patients at 3.5% (95% CI: 0.012-0.058). The analytical results classified by age showed that the incidence of malignant tumors in patients with OSA aged below 60 years was 1.8% (95% CI: 0.000-0.036), lower than that in patients aged above 60 years at 4.3% (95% CI: 0.002-0.084). The analytical results classified by the types of malignant tumors showed that the incidences of breast cancer, lung cancer, colorectal cancer, prostate cancer, kidney cancer, pancreatic cancer, and melanoma in patients with OSA were 0.5% (95% CI: 0.001-0.008), 0.5% (95% CI: 0.002-0.009), 0.5% (95% CI: 0.003-0.008), 1.1% (95% CI: 0.002-0.021), 0.3% (95% CI: 0.001-0.005), 0.1% (95% CI: 0.001-0.002), and 0.4% (95% CI: 0.003-0.005), respectively. Among them, the incidence of prostate cancer was the highest, followed by breast cancer, lung cancer, colorectal cancer, melanoma, and kidney cancer, whereas the incidence of pancreatic cancer was the lowest. However, the incidence of specific malignant tumors in patients with OSA did not have a significant increase compared with that in the general population.

CONCLUSIONS

The analytical results of this meta-analysis suggested that OSA may be associated with an overall increase in the incidence of malignancies based on the currently available data, but the connection with specific types of malignancies was not significant. Further studies are needed to explore this association in the future.

Improvement in BMI z-score following adenotonsillectomy in adolescents aged 12-18 years: a retrospective cohort study

BACKGROUND

Characteristics of obstructive sleep apnea (OSA) changes with age. Infants, toddlers and prepubertal children with OSA are usually underweight and may suffer from failure to thrive (FTT). Adenotonsillectomy (T&A) is the first line of treatment for OSA in childhood. In adults OSA is commonly associated with obesity and the metabolic syndrome. The change in body mass index (BMI) in adolescents with OSA following T&A was only sporadically studied. Thus, we peruse to examine the BMI z-score change following T&A in adolescents.

METHODS

Clalit Health Services is the largest health care organization in Israel with the largest patient registry (more than 50% of the population). Two hundred and forty two adolescents aged 12-18 who underwent T&A between 2006 and 2015 were identified in the Clalit registry and their characteristics including height and weight were retrieved. The BMI z-score of these adolescents at baseline (up to 3 months prior to T&A) and during the consecutive 3 years after T&A were analyzed and compared.

RESULTS

Changes in BMI Z-score were observed to all directions following T&A with overall small increase, not statistically significant (P = 0.26) from a median of 0.79 prior to T&A to a median of 0.835 after it. There was a minimal trend toward BMI z-score reduction in overweight children (n = 74) from 1.508 to 1.48 following T&A (p = NS), and in obese children (n = 33) from 2.288 to 2.000 (P = 0.06, 2 tailed). Interestingly thin individuals (n = 6) increased their BMI z-score following T&A from - 2.4 to - 0.59 (p = 0.046).

CONCLUSIONS

Adolescents show variable changes in their BMI z-score following T&A. In this aspect their BMI z-score change is closer to the change seen in adults treated for OSA and not that of young children. The changes observed show a trend toward normalization of the BMI z-score such that overweight children tend to decrease their BMI z-score while thin individuals tend to increase it.

Hematological Parameters Characteristics in Children with Obstructive Sleep Apnea with Obesity

Objective

To investigate the possible correlation between obesity and hematological parameters in children with obstructive sleep apnea (OSA).

Methods

A total of 460 children was initially included in our study, which were divided into children with OSA and children without OSA. Multiple analysis was performed for obesity by adjusting confounding factors such as age and gender in 460 children. Further, to minimize the influence of confounding factors and selective bias, propensity score matching (PSM) was performed in children with OSA. Hematological parameters such as inflammatory and coagulable parameters were compared between the normal weight children with OSA and the obese children with OSA following PSM.

Results

OSA (OR = 3.061; P<0.001; 95% CI, 1.772–5.288) represented an independent risk factor for obesity. Besides, the obese children with OSA had higher levels of white blood cell (WBC) (P<0.001), neutrophil (NEUT) (P<0.001), neutrophil-lymphocyte ratio (NLR) (P=0.006), fibrinogen (FIB) (P=0.033), while had a lower level of activated partial thromboplastin time (APTT) (P=0.048). No significant differences were observed in other hematological parameters. In linear regression, the results indicated that the levels of WBC (R² = 0.123, Beta = 0.289, P<0.001), NEUT (R² = 0.124, Beta = 0.282, P<0.001), NLR (R² = 0.105, Beta = 0.184, P=0.026) and FIB (R² = 0.086, Beta = 0.246, P=0.003) were positively correlated with BMI, while the level of APTT (R² = 0.057, Beta = −0.171, P=0.044) was significantly negatively correlated with BMI.

Conclusion

OSA was an independent risk factor contributing to obesity. WBC, NEUT, NLR, FIB and APTT are correlated with obesity in children with OSA (aged from 2 to 14 years). These indicators could be used to estimate the status of inflammation and hypercoagulation in the obese children with OSA.

Relationship between the mitochondria-derived peptide MOTS-c and insulin resistance in obstructive sleep apnea

PURPOSE

The co-occurrence of obstructive sleep apnea (OSA) and obesity are common. Mitochondrial open reading frame of the 12S rRNA-c (MOTS-C) is one of the newly identified mitochondrial derivative peptides that play a role in the regulation of metabolic homeostasis. We aimed to examine the serum levels of MOTS-C to help understand the role of the disease in the pathophysiology, thereby investigating whether it can contribute to the appropriate treatment.

MATERIALS AND METHODS

Seventy patients with OSAS and 20 healthy controls were included. The serum MOTS-C level was measured in all patients. For each participant, demographic features, lipid profile, serum glucose levels, and insulin levels were also evaluated. Homeostatic model assessment indicator of insulin resistance (HOMA-IR) was calculated for all participants.

RESULTS

Patients with OSAS (n = 70) were grouped as mild (n = 19), moderate (n = 19), and severe (n = 32). Patients with AHI ≤ 5 were considered as the healthy control group (n = 20). Mean age was 50.3 years and 74% (67/90) of the study sample was male. As expected, as the severity of OSA increased, BMI, insulin levels and HOMA-IR increased. MOTS-C levels were significantly lower in patients with OSA compared to healthy controls (p < 0.000) and we found that MOTS-C levels decreased as OSA severity increased. There was a negative correlation between serum MOTS-C levels and AHI and BMI (r = - 0.492, p < 0.001, r = - 0.382, p < 0.001, respectively). Serum MOTS-C levels were independently associated with AHI in BMI and HOMA-IR in linear regression analysis (p < 0.010, p < 0.007, p < 0.007, respectively).

CONCLUSION

Serum MOTS-C level is related to OSA and BMI. MOTS-C may be a useful new marker for early metabolic disorders in patients with OSA.

Sleep disorders related to nutrition and digestive diseases: a neglected clinical condition

Sleep disturbances often result from inappropriate lifestyles, incorrect dietary habits, and/or digestive diseases. This clinical condition, however, has not been sufficiently explored in this area. Several studies have linked the circadian timing system to the physiology of metabolism control mechanisms, energy balance regulation, and nutrition. Sleep disturbances supposedly trigger digestive disorders or conversely represent specific clinical manifestation of gastrointestinal (GI) diseases. Poor sleep may worsen the symptoms of GI disorders, affecting the quality of life. Conversely, short sleep may influence dietary choices, as well as meal timing, and the circadian system drives temporal changes in metabolic patterns. Emerging evidence suggests that patients with inappropriate dietary habits and chronic digestive disorders often sleep less and show lower sleep efficiency, compared with healthy individuals. Sleep disturbances may thus represent a primary symptom of digestive diseases. Further controlled trials are needed to fully understand the relationship between sleep disturbances, dietary habits, and GI disorders. It may be also anticipated that the evaluation of sleep quality may prove useful to drive positive interventions and improve the quality of life in a proportion of patients. This review summarizes data linking sleep disorders with diet and a series of disease including gastro-esophageal reflux disease, peptic disease, functional gastrointestinal disorders, inflammatory bowel diseases, gut microbiota alterations, liver and pancreatic diseases, and obesity. The evidence supporting the complex interplay between sleep dysfunction, nutrition, and digestive diseases is discussed.

Cluster analysis identifies a pathophysiologically distinct subpopulation with increased serum leptin levels and severe obstructive sleep apnea

PURPOSE

To investigate the different pathophysiologies of obstructive sleep apnea (OSA) phenotypes using cluster analysis. Differences between leptin/adiponectin levels in the resulting OSA phenotypes were also examined.

METHODS

In total, 1057 OSA patients were selected, and a retrospective survey of clinical records, polysomnography results, and blood gas data was conducted. Patients were grouped into four clusters by their OSA severity, PaCO2, body mass index (BMI), and sleepiness. A k-means cluster analysis was performed, resulting in a division into four subpopulations. The Tukey or Games-Howell tests were used for intergroup comparisons.

RESULTS

Among the 20 clinical OSA items, four common factors (Epworth Sleepiness Scale [ESS], BMI, Apnea-Hypopnea Index [AHI], and PaCO2) were extracted by principal component analysis, and a cluster analysis was performed using the k-means method, resulting in four distinct phenotypes. The Clusters 1 (middle age, symptomatic severe OSA) and 4 (young, obese, symptomatic very severe OSA) exhibited high leptin levels. C-reactive protein levels were also elevated in Cluster 4, indicating a different pathophysiological background. No apparent differences between clusters were observed regarding adiponectin/leptin ratios and adiponectin levels. Classification into groups based on phenotype showed that Epworth Sleepiness Scale [ESS] score and disease severity were not correlated, suggesting that sleepiness is affected by multiple elements.

CONCLUSIONS

The existence of multiple clinical phenotypes suggests that different pathophysiological backgrounds exist such as systemic inflammation and metabolic disorder. This classification may be used to determine the efficacy of continuous positive airway pressure treatment that cannot be determined by the AHI.

The innate immune toll-like-receptor-2 modulates the depressogenic and anorexiolytic neuroinflammatory response in obstructive sleep apnoea

The increased awareness of obstructive sleep apnoea’s (OSA) links to Alzheimer’s disease and major psychiatric disorders has recently directed an intensified search for their potential shared mechanisms. We hypothesised that neuroinflammation and the microglial TLR2-system may act as a core process at the intersection of their pathophysiology. Moreover, we postulated that inflammatory-response might underlie development of key behavioural and neurostructural changes in OSA. Henceforth, we set out to investigate effects of 3 weeks’ exposure to chronic intermittent hypoxia in mice with or without functional TRL2 (TLR2^+/+, C57BL/6-Tyrc-Brd-Tg(Tlr2-luc/gfp)Kri/Gaj;TLR2^−/−,C57BL/6-Tlr2tm1Kir). By utilising multimodal imaging in this established model of OSA, a discernible neuroinflammatory response was demonstrated for the first time. The septal nuclei and forebrain were shown as the initial key seed-sites of the inflammatory cascade that led to wider structural changes in the associated neurocircuitry. Finally, the modulatory role for the functional TLR2-system was suggested in aetiology of depressive, anxious and anorexiolytic symptoms in OSA.

A contemporary review of obstructive sleep apnea

PURPOSE OF REVIEW

This review provides a contemporary review of sleep apnea with emphasis on definitions, epidemiology, and consequences.

RECENT FINDINGS

Amyloid β-42 is one of the main peptides forming amyloid plaques in the brains of Alzheimer patients. Poorer sleep quality and shorter sleep duration have been associated with a higher amyloid burden. Decreased sleep time in the elderly is a precipitating factor in amyloid retention. Studies have shown that the dysregulation of the homeostatic balance of the major inhibitory and excitatory amino acid neurotransmitter systems of gamma-aminobutyric acid (GABA) and glutamate play a role in sleep disordered breathing (SDB).

SUMMARY

Untreated sleep disordered breathing (obstructive sleep apnea and/or central sleep apnea) are an important cause of medical mortality and morbidity. OSA is characterized by recurrent episodes of partial or complete collapse of the upper airway during sleep followed by hypoxia and sympathetic activation. Apneic events are terminated by arousal, followed by increases in pulse and blood pressure, and re-oxygenation and the release of inflammatory factors. Individuals with OSA have an increased risk of developing atrial fibrillation. Hypoxemia and poor sleep quality because of OSA increase the risk of cognitive decline in the elderly.

Upper Airway Obstruction Elicited Energy Imbalance Leads to Growth Retardation that Persists after the Obstruction Removal

Upper airway obstruction can lead to growth retardation by unclear mechanisms. We explored the effect of upper airway obstruction in juvenile rats on whole-body energy balance, growth plate metabolism, and growth. We show that after seven weeks, obstructed animals’ ventilation during room air breathing increased, and animals grew less due to abnormal growth plate metabolism. Increased caloric intake in upper airway-obstructed animals did not meet increased energy expenditure associated with increased work of breathing. Decreased whole-body energy balance induced hindrance of bone elongation following obstruction removal, and array pathways regulating growth plate development and marrow adiposity. This is the first study to show that rapidly growing animals cannot consume enough calories to maintain their energy homeostasis, leading to an impediment in growth in the effort to save energy.

Irreversible metabolic abnormalities following chronic upper airway loading

STUDY OBJECTIVES

Treatment of obstructive sleep apnea increases obesity risk by an unclear mechanism. Here, we explored the effects of upper airway obstruction and its removal on respiratory homeostasis, energy expenditure, and feeding hormones during the sleep/wake cycle from weaning to adulthood.

METHODS

The tracheas of 22-day-old rats were narrowed, and obstruction removal was performed on post-surgery day 14. Energy expenditure, ventilation, and hormone-regulated feeding were analyzed during 49 days before and after obstruction.

RESULTS

Energy expenditure increased and body temperature decreased in upper airway obstruction and was only partially recovered in obstruction removal despite normalization of airway resistance. Increased energy expenditure was associated with upregulation of ventilation. Decreased body temperature was associated with decreased brown adipose tissue uncoupling protein 1 level, suppressed energy expenditure response to norepinephrine, and decreased leptin level. Upper airway obstructed animals added less body weight, in spite of an increase in food intake, due to elevated hypothalamic orexin and neuropeptide Y and plasma ghrelin. Animals who underwent obstruction removal fed more due to an increase in hypothalamic neuropeptide Y and plasma ghrelin.

CONCLUSIONS

The need to maintain respiratory homeostasis is associated with persistent abnormal energy metabolism and hormonal regulation of feeding. Surgical treatment per se may not be sufficient to correct energy homeostasis, and endocrine regulation of feeding may have a larger effect on weight change.

Interdisciplinary Weight Loss and Lifestyle Intervention for Obstructive Sleep Apnoea in Adults: Rationale, Design and Methodology of the INTERAPNEA Study

Obesity is a major risk factor for obstructive sleep apnoea (OSA), the most common sleep-disordered breathing related to neurocognitive and metabolic syndromes, type II diabetes, and cardiovascular diseases. Although strongly recommended for this condition, there are no studies on the effectiveness of an interdisciplinary weight loss and lifestyle intervention including nutrition, exercise, sleep hygiene, and smoking and alcohol cessation. INTERAPNEA is a randomised controlled trial with a two-arm parallel design aimed at determining the effects of an interdisciplinary tailored weight loss and lifestyle intervention on OSA outcomes. The study will include 84 males aged 18–65 with a body mass index of ≥25 kg/m² and severe to moderate OSA randomly assigned to usual care (i.e., continuous positive airway pressure), or interdisciplinary weight loss and lifestyle intervention combined with usual care. Outcomes will be measured at baseline, intervention end-point, and six-month post-intervention, including apnoea-hypopnoea index (primary outcome), other neurophysical and cardiorespiratory polysomnographic outcomes, sleep quality, daily functioning and mood, body weight and composition, physical fitness, blood biomarkers, health-related quality of life, and cost-effectiveness. INTERAPNEA may serve to establish a cost-effective treatment not only for the improvement of OSA and its vast and severe comorbidities, but also for a potential remission of this condition.

Effects of Continuous Positive Airway Pressure on Body Composition in Individuals with Obstructive Sleep Apnea: A Non-Randomized, Matched Before-After Study

A reciprocal relationship between obesity and obstructive sleep apnea (OSA) likely exists, wherein obesity contributes to OSA, and OSA-related sleep disturbances promote weight gain. It remains unclear whether continuous positive airway pressure (CPAP) affects body composition. We conducted an open-label, parallel-arm, non-randomized, matched before-after study in individuals with OSA who were starting CPAP use (n = 12) and who were not (n = 12) to examine the effects of CPAP on total body composition (via air displacement plethysmography) including fat and fat-free mass. CPAP users (n = 12) were studied at baseline and after 8 weeks of CPAP use, and 12 age- and sex-matched non-CPAP OSA controls were studied at baseline and after an 8 week period. Statistically significant group x time interactions were seen for body weight, fat-free mass, and fat-mass, such that body weight and fat-free mass were increased, and fat mass decreased, at 8-week follow-up in the CPAP group compared to baseline. Body weight and body composition measures were unchanged in the non-CPAP control group. These findings are consistent with prior studies showing CPAP-induced weight gain, and suggest that weight gain observed following CPAP may be driven primarily by increases in fat-free mass. An increase in lean mass (and decrease in fat mass), despite an overall increase in body weight, can be considered a favorable metabolic outcome in response to CPAP use.

Effect of lorcaserin on weight reduction in persons with obstructive sleep apnea (OSA): a combined subgroup analysis from three randomized, controlled clinical trials

STUDY OBJECTIVES

To evaluate weight loss with lorcaserin in persons with obstructive sleep apnea (OSA).

METHODS

This retrospective analysis evaluated weight loss of lorcaserin (10 mg twice daily) versus placebo in persons with obesity or overweight persons with OSA from a pooled database of three randomized, controlled trials. Primary end points were reductions in the baseline body weight of ≥5% and ≥10% at year 1 and overall weight change at year 1. Changes in heart rate and blood pressure were also evaluated.

RESULTS

A total of 336 persons with OSA were identified in the overall pooled population (N = 6,636). At year 1, more patients receiving lorcaserin lost ≥5% (47.2% lorcaserin vs. 25.6% placebo; p < 0.0001) and 10% (22.2% lorcaserin vs. 13.1% placebo; p < 0.0354) of their baseline body weight. Weight loss at year 1 was 6.4 kg versus 3.5 kg in the lorcaserin and placebo groups, respectively (p < 0.0001). Similar results were observed for change in blood pressure and heart rate, with responders having larger benefits. Weight loss was similar between persons with and without OSA.

CONCLUSIONS

In this retrospective analysis, persons with OSA showed significant and meaningful weight loss, blood pressure and heart rate reductions in patients treated with lorcaserin versus placebo. Persons with OSA lost just as much weight as those without OSA. Health care providers can expect persons with OSA to lose weight by diet, exercise and the weight loss medication lorcaserin comparable with persons without OSA. Further prospective research is warranted to evaluate impact of weight loss on OSA and overall outcomes for patients.

A comprehensive diagnostic approach to detect underlying causes of obesity in adults

Obesity is a worldwide growing problem. When confronted with obesity, many health care providers focus on direct treatment of the consequences of adiposity. We plead for adequate diagnostics first, followed by an individualized treatment. We provide experience-based and evidence-based practical recommendations (illustrated by clinical examples), to detect potential underlying diseases and contributing factors. Adult patients consulting a doctor for weight gain or obesity should first be clinically assessed for underlying diseases, such as monogenetic or syndromic obesity, hypothyroidism, (cyclic) Cushing syndrome, polycystic ovarian syndrome (PCOS), hypogonadism, growth hormone deficiency, and hypothalamic obesity. The most important alarm symptoms for genetic obesity are early onset obesity, dysmorphic features/congenital malformations with or without intellectual deficit, behavioral problems, hyperphagia, and/or striking family history. Importantly, also common contributing factors to weight gain should be investigated, including medication (mainly psychiatric drugs, (local) corticosteroids, insulin, and specific β-adrenergic receptor blockers), sleeping habits and quality, crash diets and yoyo-effect, smoking cessation, and alcoholism. Other associated conditions include mental factors such as chronic stress or binge-eating disorder and depression.Identifying and optimizing the underlying diseases, contributing factors, and other associated conditions may not only result in more effective and personalized treatment but could also reduce the social stigma for patients with obesity.

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

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

The shifting relationship between weight and pediatric obstructive sleep apnea: A historical review

OBJECTIVES

For more than a century, pediatric obstructive sleep apnea (OSA) was associated with failure to thrive. However, that association has faded over the last few decades. A 21st century child with OSA is much more likely to be overweight than underweight. This raises the question: Has pediatric OSA changed over time, or has the rise of childhood obesity in the United States created a new, separate disease? This literature review explores the historical shift in the relationship between weight and OSA, and the associated changes in treatment.

RESULTS

We demonstrate a clear transition in the prevalence of failure to thrive and obesity in the OSA literature in the mid-2000s. What is less clear is whether these two clinical phenotypes should be considered two distinct diseases, or whether subtle differences in one set of pathophysiologic pathways-adenotonsillar hypertrophy, altered inflammation, and increased energy expenditure-can lead to divergent metabolic outcomes. More research is needed to fully elucidate the pathophysiology of OSA in children with obesity.

CONCLUSIONS

We may need new and different treatments for obesity-associated OSA as adenotonsillectomy-which is effective at reversing failure to thrive in OSA-is not as effective at treating OSA in children with obesity. One option is drug-induced sleep endoscopy, which could personalize and improve surgical treatment of OSA. There is some evidence that therapies used for OSA in adults (e.g., weight loss and positive airway pressure) are also helpful for overweight/obese children with OSA. Laryngoscope, 129:2414-2419, 2019.

Bidirectional Relationships Between Weight Change and Sleep Apnea in a Behavioral Weight Loss Intervention

OBJECTIVE

To examine the bidirectional relationship between weight change and obstructive sleep apnea (OSA) in the context of a behavioral weight loss intervention.

PATIENTS AND METHODS

Adults who were overweight or obese (N=114) participated in a 12-month behavioral weight loss intervention from April 17, 2012, through February 9, 2015. The apnea-hypopnea index (AHI), a marker of the presence and severity of OSA, was assessed at baseline, 6 months, and 12 months. Linear mixed models evaluated the effect of weight change on the AHI and the effect of OSA (AHI ≥5) on subsequent weight loss. Secondary analyses evaluated the effect of OSA on intervention attendance, meeting daily calorie goals, and accelerometer-measured physical activity.

RESULTS

At baseline, 51.8% of the sample (n=59) had OSA. Adults who achieved at least 5% weight loss had an AHI reduction that was 2.1±0.9 (adjusted mean ± SE) events/h greater than those with less than 5% weight loss (P<.05). Adults with OSA lost a mean ± SE of 2.2%±0.9% less weight during the subsequent 6-month interval compared with those without OSA (P=.02). Those with OSA were less adherent to daily calorie goals (mean ± SE: 25.2%±3.3% vs 34.8%±3.4% of days; P=.006) and had a smaller increase in daily activity (mean ± SE: 378.3±353.7 vs 1060.1±377.8 steps/d; P<.05) over 12 months than those without OSA.

CONCLUSION

Behaviorally induced weight loss in overweight/obese adults was associated with significant AHI reduction. However, the presence of OSA was associated with blunted weight loss, potentially via reduced adherence to behaviors supporting weight loss. These results suggest that OSA screening before attempting weight loss may be helpful to identify who may benefit from additional behavioral counseling.

Effects of obesity therapies on sleep disorders

Obesity is a significant risk factor for obstructive sleep apnea syndrome (OSAS), and has also been linked to reductions in sleep quality and quantity. Weight loss has been shown to be an effective treatment for improving OSAS; however, there is a high degree of variability in improvements of OSAS in response to weight loss. There are three modalities of obesity therapies: 1) lifestyle modification, which includes changes in dietary intake and physical activity, along with behavioral interventions; 2) pharmacologic agents; and 3) bariatric surgery. Individuals have a highly variable response to the various obesity interventions, and maintenance of weight loss can be especially challenging. These factors influence the effect of weight loss on sleep disorders. There is still a need for large, well-controlled studies examining short- and long-term efficacy of weight loss modalities and their impact on long-term treatment of OSAS and other sleep parameters, particularly in youth. Nonetheless, given our current knowledge, weight reduction should always be encouraged for people coping with obesity, OSAS, and/or sleep disruptions and resources identified to assist patients in choosing a weight loss approach that will benefit them the most.