Effects of continuous positive airway pressure on energy balance regulation: a systematic review

Clustering of intuitive eating and psychological health identifies subgroups associated with weight loss following semaglutide

OBJECTIVE

Obesity management requires personalized approaches. Using data from the Aviitam platform in France, this study aimed to do the following: 1) explore psychological and behavioral patterns through clustering techniques; 2) validate the robustness of these clusters; and 3) assess their association with weight-loss outcomes in severe obesity under semaglutide treatment.

METHODS

Phase 1 included 989 adults with BMI ≥ 25 kg/m2 who completed validated questionnaires, including the Hospital Anxiety and Depression Scale (HADS) and Intuitive Eating Scale-2 (IES-2). Phase 2 validated robustness in 492 individuals. Phase 3 applied clusters to 125 individuals with BMI ≥ 40 kg/m2 who were treated with semaglutide 2.4 mg/week at Montpellier University Hospital, assessing weight-loss trajectories over 12 months.

RESULTS

The following two clusters were identified: the Intuitive Eaters Group (IEG, n = 482); and the Emotionally Driven Eaters Group (EDEG, n = 507). The IEG exhibited lower emotional distress and higher intuitive eating scores. HADS and IES-2 distinguished clusters effectively (area under the curve, 0.95). Robustness was confirmed in Phase 2. In Phase 3, the IEG demonstrated a significantly more favorable weight-loss trajectory compared to the EDEG (p = 0.03).

CONCLUSIONS

Psychological and behavioral clusters identified through HADS and IES-2 are associated with weight loss under semaglutide treatment, suggesting the value of integrating psychological and behavioral profiling into obesity care.

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.

Associations between obstructive sleep apnea risk and urinary incontinence: Insights from a nationally representative survey

Obstructive sleep apnea (OSA) and urinary incontinence (UI) are two prevalent health conditions with significant impacts on individuals' quality of life. Although they appear distinct in nature, a growing body of evidence suggests a potential interrelationship between these conditions. Our objective was to explore the association between the risk of OSA and the occurrence of UI within a nationally representative sample of U.S. adults. Utilizing cross-sectional data from the National Health and Nutrition Examination Survey spanning the years 2015 to 2020, we conducted an analysis on a sample comprising 8,647 adults who provided comprehensive self-reported information on both UI and sleep apnea symptoms. The included cohorts were analyzed based on their sex. We employed the Multivariate Apnea Prediction (MAP) index to evaluate the risk of OSA. Subgroup analyses were conducted, categorizing them according to different types of UI. The association between OSA risk and UI was estimated through multivariable binary logistic regression models. After adjusting for relevant confounders, our results revealed a positive correlation between OSA risk and UI in both males (OR = 5.68, 95% CI = 1.74-18.47) and females (OR = 5.99, 95% CI = 2.68-13.41). The subgroup analysis illustrates that an elevated risk of OSA heightens the likelihood of experiencing stress urinary incontinence (SUI), urge urinary incontinence (UUI), and mixed urinary incontinence (MUI) in both male and female populations. Our study findings imply that an elevated risk of OSA exacerbates the likelihood of UI, SUI, UUI and MUI.

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.

Long-Term Adherence in Overweight Patients with Obstructive Sleep Apnea and Hypertension-A Pilot Prospective Cohort Study

Obstructive sleep apnea (OSA) is associated with increased cardiovascular risk, sedentarism, depression, anxiety and impaired quality of life. The long-term effectiveness of positive airway pressure (PAP) is insufficiently studied and limited by poor patient compliance. The aim of this pilot prospective cohort study was to evaluate long-term adherence in overweight patients with moderate-severe OSA and hypertension and to analyze changes in weight, sleepiness and quality of life. We performed a prospective study that included overweight patients with moderate-severe OSA and hypertension who had not undergone previous PAP therapy. All subjects received a standard physical examination, education regarding lifestyle changes and free PAP therapy for 2 months. After five years, the patients were invited to participate in a telephone-based interview regarding PAP compliance and completed standard questionnaires assessing adherence to medication, physical activity, diet, anxiety and quality of life (QoL). Only 39.58% of the patients were adherent to PAP 5 years (58.42 ± 3.70 months) after being diagnosed with moderate-severe OSA. Long-term PAP use results in sustained weight loss; improved blood pressure control, sleepiness and QOL; and lower anxiety and depression scores. PAP compliance was not associated with a higher level of daily physical activity or a healthier diet.

Effect of surgical intervention for childhood OSA on blood pressure: A randomized controlled study

OBJECTIVE

To investigate the effect of surgical intervention on 24-h ABP in children with OSA. It was hypothesized that blood pressure would improve following adenotonsillectomy.

METHODS

This was a two-centered investigator-blinded randomized controlled trial. Non-obese pre-pubertal children aged 6-11 years with OSA (obstructive apnea-hypopnea index, OAHI >3/h) underwent 24-h ABP monitoring at baseline and 9 months after the randomly assigned intervention, i.e. Early Surgery (ES) or Watchful Waiting (WW). Intention-to-treat analysis was performed.

RESULTS

137 subjects were randomized. Sixty-two (Age: 7.9y ± 1.3, 71% boys) and 47 (Age: 8.5y ± 1.6, 77% boys) participants from the ES and WW groups, respectively completed the study. Changes in ABP parameters were similar in the ES and WW groups (nighttime systolic BP z-scores: +0.03 ± 0.93 vs. -0.06 ± 1.04, p = 0.65; nighttime diastolic BP z-scores: -0.20 ± 0.95 vs. -0.02 ± 1.00, p = 0.35) despite a greater improvement in OSA in the ES group. However, a reduction in nighttime diastolic BP z-score correlated with improvements in OSA severity indexes (r = 0.21-0.22, p < 0.05), and a significant improvement in nighttime diastolic BP z-score [-0.43 ± 1.01, p = 0.027] following surgery was observed in participants with severe preoperative OSA (OAHI ≥10/h). The ES group had a significant increase in body mass index z-score after surgery [+0.27 ± 0.57, p < 0.001], which correlated with the increase in daytime systolic BP z-score (r = 0.2, p < 0.05).

CONCLUSION

Surgical treatment did not lead to significant improvements in ABP in OSA children except in those with more severe disease. The improvement in BP was partially masked by the weight gain following surgery.

CLINICAL TRIAL REGISTRATION

The trial was registered with the Chinese Clinical Trial Registry (http://www.chictr.org.cn.

REGISTRATION NUMBER

ChiCTR-TRC-14004131).

Designing a program to support weight loss for patients attending the sleep medicine clinic: a qualitative study

STUDY OBJECTIVES

Excess body weight is the most important risk factor in sleep-disordered breathing. Weight loss is a treatment alternative to positive airway pressure therapy, but there is a knowledge gap of what is feasible, acceptable, and sustainable in this population. We seek to add the voices of sleep medicine patients and providers to the medical literature to understand what makes this population unique when considering weight loss, and what we can do differently to create more sustainable weight loss interventions.

METHODS

We conducted one-on-one semistructured interviews with 12 patients with obstructive sleep apnea/obesity hypoventilation syndrome and obesity and with 9 sleep medicine providers regarding previous weight loss efforts, perceptions of barriers to and facilitators of weight loss, and potential components of a program to support those with sleep apnea and excess weight.

RESULTS

Patients indicated they appreciated direct conversation with their sleep physician regarding weight loss and providers felt the patient population was generally very receptive to weight loss conversations. Patients emphasized the most important aspects of a future weight loss program would be personalized diet, exercise, accountability, integration of technology, and an individualized approach to addressing the psychological aspects of eating.

CONCLUSIONS

This is a unique population of patients who are very receptive to conversations about weight loss. We plan to use this data to inform a future weight loss program based in health coaching to address the specific needs of this population.

CITATION

Dupuy-McCauley K, Benzo R, Barwise A. Designing a program to support weight loss for patients attending the sleep medicine clinic: a qualitative study. J Clin Sleep Med. 2023;19(3):459-471.

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.

Identifying the Predictors of Short Term Weight Loss Failure after Roux-En-Y Gastric Bypass

INTRODUCTION

Gastric bypass surgery is a gold standard therapy for severe obesity. This study aimed to evaluate anthropometric predictors for short-term excess weight loss (EWL) after Roux-en-Y gastric bypass surgery (RYGB) in a sample of severely obese patients.

MATERIALS AND METHODS

This cohort study was conducted on severely obese candidates for RYGB bariatric surgery in Mashhad, Iran. Indirect calorimetry, anthropometric measurements, and body composition data were collected before, one, and six months after RYGB.

RESULTS

Fifty-four participants (43, 79.6% women and 11, 20.4% men) with a mean age of 39.63 ± 9.66 years participated in this study. The mean total weight and BMI loss within six months were 32.89 ± 20.22 kg and 12.37 ± 7.34 kg/m², respectively. The mean reduction in adipose tissue and fat-free mass was 24.49 kg and 7.46 kg, respectively. The mean resting metabolism rate (RMR) reduction at one and six months after RYGB was 260.49 kcal and 396.07 kcal, respectively. There was a significant difference in mean RMR between the baseline and one and six months after RYGB (p < 0.001). There was no significant gender difference in mean weight and BMI loss percentage at six months post-RYGB (p > 0.05). Baseline skeletal muscle mass (SMM), excess BMI loss (EBMIL) at first month after surgery, and baseline neck circumference (NC) could predict EWL six months after surgery.

CONCLUSION

Reduced RMR shortly after RYGB may be due to FFM reduction. Some anthropometric and their acute changes after RYGB may predict the short-term EWL in RYGB patients.

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.

Analyses of Weight/Blood Pressure Changes before and after Tonsillectomy in Adults: A Longitudinal Follow-Up Study

This study aimed to evaluate the changes in weight and blood pressure in Korean adults who underwent tonsillectomy compared to controls. A nested case-control study used data from the Korean National Health Insurance Service-Health Screening Cohort (2002–2015). Tonsillectomy was defined using claim code Q2300. The changes in weight and systolic/diastolic blood pressure (SBP/DBP) were measured before tonsillectomy and 1 year after tonsillectomy (study I) in some participants and during the second year after tonsillectomy (study II) in other participants. Patients who underwent tonsillectomy (n = 569 in study I; n = 556 in study II) were 1:4 matched with control participants (n = 2276 in study I; n = 2224 in study II). The paired t-test and linear mixed model were used to test the differences between groups at each time point. There were no changes in body mass index (p = 0.732 in study I; p = 0.128 in study II), SBP (p = 0.344 in study I; p = 0.559 in study II), or DBP (p = 0.826 in study I; p = 0.524 in study II) between the tonsillectomy patients and controls in the first or second year postoperatively. Subgroup analyses by age, sex, and degree of obesity showed consistent results. Tonsillectomy does not lead to a change in weight or blood pressure in Korean adults.

Mood, sleepiness, and weight gain after three years on CPAP therapy for sleep apnoea

Background: The prevalence of obstructive sleep apnoea syndrome (OSAS) keeps on rising. Daytime sleepiness resulting from fragmented sleep is the prime symptom, and obesity the major risk factor for OSAS. Quality of life with OSAS is often affected by depressive symptoms and anxiety. Nasal continuous positive airway pressure (CPAP) therapy reduces daytime sleepiness, but the results on the effect on mood, physical activity, and weight are controversial especially on long-term therapy. Purpose of this study was to evaluate these factors and predictors of weight gain during long-term CPAP therapy.

Methods: Consecutive patients (n = 223), referred to sleep study with suspected OSAS, were enrolled. Patients underwent a cardiorespiratory polygraphy at baseline and a battery of questionnaires was completed, both at baseline, and after three years of follow-up. Total of 149 (67%; M 65, F 84) patients completed the follow-up. Of the 149 patients, 76 (51.0%; M 32, F 44) used CPAP.

Results: In this study, depressive symptoms, anxiety, and sleepiness were alleviated during CPAP therapy. However, therapy did not have an influence on cravings of different food categories, or exercise habits and exercise duration. From the various factors studied, solely higher adherence to CPAP therapy was associated with weight gain.

Conclusions: This research provides further evidence that long-term CPAP therapy in patients with OSAS not only decreases sleepiness and improves sleep quality but could also alleviate depressive symptoms and anxiety. In addition, our study reinforces that CPAP therapy alone is not sufficient for weight management in patients with OSAS. Regardless of comprehensive battery of questionnaires, we were unable to establish markers predicting weight gain during therapy. We advise on life-style counselling and weight management program to all patients with obesity on CPAP therapy.

Effect of continuous positive airway pressure on maximal exercise capacity in patients with obstructive sleep apnea: a systematic review and meta-analysis

STUDY OBJECTIVES

Exercise capacity is impaired in obstructive sleep apnea (OSA). There are conflicting reports on the effect of continuous positive airway pressure (CPAP) on maximal exercise capacity. The objective of this review was to determine if there is a change in exercise capacity and anaerobic threshold following CPAP treatment in OSA patients.

METHODS

We conducted a systematic review and meta-analyses to summarize the changes in peak rate of oxygen uptake (V̇O₂ peak) or maximum rate of oxygen uptake (V̇O2 max) and anaerobic threshold (AT) during cardiopulmonary exercise testing following CPAP intervention in patients with OSA. A systematic literature review was conducted to identify published literature on markers of V̇O₂ peak, V̇O₂ max, and AT pre- vs post-CPAP using a web-based literature search of PubMed/MEDLINE, Embase, CINAHL, and Cochrane review (CENTRAL) databases. Two independent reviewers screened the articles for data extraction and analysis.

RESULTS

The total search of all the databases returned 470 relevant citations. Following application of eligibility criteria, 6 studies were included in the final meta-analysis for V̇O₂ peak, 2 studies for V̇O₂ max, and five studies for AT. The meta-analysis showed a mean net difference in V̇O₂ peak between pre- and post-CPAP of 2.69 mL·kg^-1·min^-1, P = .02, favoring treatment with CPAP. There was no difference in V̇O₂ max or AT with CPAP treatment (mean net difference 0.66 mL·kg^-1·min^-1 [P = .78] and -144.98 mL·min^-1 [P = .20] respectively).

CONCLUSIONS

There is a paucity of high-quality studies investigating the effect of CPAP on exercise capacity. Our meta-analysis shows that V̇O₂ peak increases following CPAP treatment in patients with OSA, but we did not observe any change in V̇O₂ max or AT. Our findings should be considered preliminary and we recommend further randomized controlled trials to confirm our findings and to clarify the peak and maximum rates of oxygen uptake adaptations with CPAP therapy.

Long-Term Effects of Continuous Positive Airway Pressure (CPAP) Therapy on Obesity and Cardiovascular Comorbidities in Patients with Obstructive Sleep Apnea and Resistant Hypertension-An Observational Study

BACKGROUND

We sought to investigate whether long-term continuous positive airway pressure (CPAP) treatment in patients with obstructive sleep apnea (OSA) and resistant hypertension (RHTN) could attenuate the cardiovascular disease risk by lowering their body-mass index (BMI).

METHODS

This was a long-term observational study of RHTN patients diagnosed with OSA. Patients were evaluated with polysomnography initially and after a mean follow-up period of four years. The patients were divided into two groups based on their compliance to CPAP therapy.

RESULTS

33 patients (aged 54.67 ± 7.5, 18 men, 54.5%) were included in the study, of which 12 were compliant to CPAP therapy. A significant reduction in BMI at follow-up was noted in patients compliant to CPAP therapy (1.4 ± 3.5 vs. -1.6 ± 2.5, p = 0.006). We also noted a large effect size reduction in abdominal circumference at follow-up in the CPAP group. At follow-up evaluation, the mean heart rate (b/min) was lower in the CPAP group (58.6 ± 9.5 vs. 67.8 ± 7.8), while arrhythmia prevalence increased between initial (28.6%) and follow-up (42.9%) evaluation with an intermediate effect size in non-compliant patients.

CONCLUSIONS

In our cohort of OSA patients with RHTN, long-term adherence to CPAP therapy was associated with weight loss and improvement in cardiac rhythm outcomes.

Leptin: Master Regulator of Biological Functions that Affects Breathing

Obesity is a global epidemic in developed countries accounting for many of the metabolic and cardiorespiratory morbidities that occur in adults. These morbidities include type 2 diabetes, sleep-disordered breathing (SDB), obstructive sleep apnea, chronic intermittent hypoxia, and hypertension. Leptin, produced by adipocytes, is a master regulator of metabolism and of many other biological functions including central and peripheral circuits that control breathing. By binding to receptors on cells and neurons in the brainstem, hypothalamus, and carotid body, leptin links energy and metabolism to breathing. In this comprehensive article, we review the central and peripheral locations of leptin's actions that affect cardiorespiratory responses during health and disease, with a particular focus on obesity, SDB, and its effects during early development. Obesity-induced hyperleptinemia is associated with centrally mediated hypoventilation with decrease CO₂ sensitivity. On the other hand, hyperleptinemia augments peripheral chemoreflexes to hypoxia and induces sympathoexcitation. Thus, "leptin resistance" in obesity is relative. We delineate the circuits responsible for these divergent effects, including signaling pathways. We review the unique effects of leptin during development on organogenesis, feeding behavior, and cardiorespiratory responses, and how undernutrition and overnutrition during critical periods of development can lead to cardiorespiratory comorbidities in adulthood. We conclude with suggestions for future directions to improve our understanding of leptin dysregulation and associated clinical diseases and possible therapeutic targets. Lastly, we briefly discuss the yin and the yang, specifically the contribution of relative adiponectin deficiency in adults with hyperleptinemia to the development of metabolic and cardiovascular disease. © 2020 American Physiological Society. Compr Physiol 10:1047-1083, 2020.

Efficacy of continuous positive airway pressure on subcutaneous adipose tissue in patients with obstructive sleep apnea: a meta-analysis of randomized controlled trials

PURPOSE

It remains inconclusive whether continuous positive airway pressure (CPAP) therapy can significantly reduce subcutaneous adipose tissue (SAT) in patients with obstructive sleep apnea (OSA). This meta-analysis of randomized controlled trials (RCTs) aimed to evaluate the impact of CPAP treatment on SAT in patients with OSA.

METHODS

We searched Pubmed, Cochrane, Web of Science, and Embase for RCTs, which investigated the effectiveness of CPAP treatment in reducing SAT among patients with OSA. Following the PRISMA guidelines, we extracted information on the study and patient characteristics, and pre- and post-CPAP measures of SAT. We then calculated the overall effects using the standardized mean difference (SMD) with a 95% confidence interval (CI).

RESULTS

A total of 5 RCTs (comprising 153 patients) met inclusion criteria for the meta-analysis. We found that the SAT did not change before and after CPAP treatment in patients with OSA (SMD = - 0.02, 95% CI - 0.25 to 0.2, z = 0.19, p = 0.85). Subgroup analyses indicated that the outcome was not affected by age, CPAP therapy duration, baseline body mass index, and measure utilized.

CONCLUSION

This meta-analysis of RCTs suggests that CPAP therapy does not significantly decrease the level of SAT among patients with OSA. Further large-scale, and high-quality randomized controlled trials are needed to better address this issue.

Intermittent hypoxia, energy expenditure, and visceral adipocyte recovery

BACKGROUND AND OBJECTIVE

Body weight of patients with obstructive sleep apnea after initiation of nasal continuous positive airway pressure appears to increase. We hypothesized that intermittent hypoxia (IH) will decrease energy expenditure (EE), and that normoxic recovery will lead to body weight gains.

METHODS

C57BL/6 J male mice were exposed to either 12 h/day of mild IH (alternating F_IO₂-10-11% and 21%; 640 s cycle), or severe IH (F_IO₂-6-7%-21%; 180 s cycle) or sham IH daily for 4 or 8 weeks. After exposures, EE was evaluated while mice were kept under normoxia for 5 weeks and organ histology was evaluated.

RESULTS

EE was not decreased by IH. However, visceral white adipocyte size after normoxic recovery was significantly increased in severe IH in an intensity-dependent manner.

CONCLUSION

Our hypothesis that IH would decrease EE was not corroborated. However, IH and normoxic recovery seem to promote severity-dependent enlargement of visceral adipocytes, likely reflecting altered energy preservation mechanisms induced by IH.

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.

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.

Gender-specific change in leptin concentrations during long-term CPAP therapy

Purpose

Nasal continuous positive airway pressure (CPAP) alleviates sleepiness in patients with obstructive sleep apnoea syndrome (OSAS), but part of OSAS patients keep gaining weight. Leptin and insulin-like growth factor-1 (IGF-1) interact with energy balance, and CPAP therapy has been suggested to influence these endocrine factors. We hypothesised that leptin would decrease during long-term CPAP therapy, and weight gain would associate with OSAS severity, lower CPAP adherence, lower IGF-1, and leptin concentrations.

Methods

Consecutive patients (n = 223) referred to sleep study with suspected OSAS were enrolled. Patients underwent cardiorespiratory polygraphy at baseline. Questionnaires were completed, and blood samples were drawn both at baseline and after 3 years. A total of 149 (67%; M 65, F 84) patients completed the follow-up. Plasma samples were available from 114 patients, 109 of which with CPAP adherence data (49 CPAP users, 60 non-users).

Results

At baseline, the CPAP users were more obese and had more severe OSAS than the non-users. Leptin concentrations did not differ. After follow-up, leptin concentrations were higher in CPAP users (30.2 ng/ml vs. 16.8 ng/ml; p = 0.001). In regression analysis, increase in leptin concentrations was independent of age, baseline body mass index (BMI), or the change in BMI. Leptin concentrations increased among females (− 8.9 vs. 12.7 ng/ml; p < 0.001); whereas in men, CPAP did not have an effect, if not opposed the natural decrease in leptin observed in men not using CPAP. Change in IGF-1 levels did not differ.

Conclusions

Our results suggest increase in leptin concentrations during long-term CPAP therapy among females.

Electronic supplementary material

The online version of this article (10.1007/s11325-019-01846-y) contains supplementary material, which is available to authorized users.

Physical activity and exercise in obstructive sleep apnea

OBJECTIVES

In the last decade significant research has focused on the relationship between physical activity (PA), exercise and obstructive sleep apnea (OSA). The purpose of this study is to provide an overview and interpretation of different studies regarding this subject.

METHODS

PubMed, Embase and Cochrane Library databases were searched for English articles published before August 21, 2017. Search terms were 'Sleep Apnea, Obstructive' and 'Exercise'.

RESULTS

Low levels of PA are associated with higher odds of OSA. A negative correlation between PA level and OSA severity is shown, even after adjusting for baseline differences. OSA also impairs the aerobic exercise capacity significantly. OSA patients have a poor hemodynamic response to exercise, which is related to OSA severity. Findings on the influence of continuous positive airway pressure (CPAP) on PA in OSA are inconsistent in terms of statistical significance. A regular and predominantly aerobic exercise training significantly reduces OSA severity, even without a significant decrease in body weight.

CONCLUSION

The available evidence suggests that further research is necessary to explore the relationships between PA, exercise and OSA and to examine the efficacy of exercise as alternative or additional treatment for OSA.

Erickson health coaching: An innovative approach for weight management in obese patients with obstructive sleep apnoea?

Obstructive sleep apnoea (OSA) is a highly prevalent medical condition and amajor cardiovascular risk factor. Obesity is present in ∼70% of patients with OSA, nevertheless, continuous positive airway pressure (CPAP) ventilation - the gold standard therapy for moderate and severe OSA - has no appreciable long-term beneficial effects on obesity, body composition, energy metabolism, physical activities or the incidence of major cardiovascular events. Therefore, effective weight loss strategies in conjunction with CPAP therapy in OSA are critically needed. Since lifestyle interventions may positively impact body weight, there is a strong rationale to testing the hypothesis that Erikson coaching intervention as a form of lifestyle intervention to obese patients with OSA may increase their adherence to healthy lifestyle behaviour and thus result in weight reduction, improved body composition (reduction in %body fat) and improvements in glucose and lipid metabolism. There are three lines of evidence to justify testing this hypothesis: First, health coaching significantly facilitates uptake of healthy behaviours across a broad variety of chronic conditions; second, several randomized clinical trials suggested positive impact of health coaching on weight management and on cardiometabolic risk factors in overweight/obese otherwise healthy persons; third, Erickson coaching approach empowers the three key elements of health coaching (patient-centeredness, patient-determined goals, use of a self-discovery process) further, namely by introducing two other specific core elements into the coaching process: a) solution-focus and outcome frame, b) orientation at the patient-formulated positive outcomes (i.e., positive values resulting from behavioural change). Importantly, results of our recent pilot observational cohort study suggested that Erickson coaching is a powerful tool to address behavioural modification in obesity. In conclusion, testing our hypothesis may have significant clinical implications: if clinical randomized trials indicate that Erickson health coaching is an efficient approach to behavioural change and weight management in OSA then combining Erickson coaching with CPAP therapy may result in reductions in cardiovascular morbidity and mortality in these high-risk patients.

Factors influencing adherence to continuous positive airway pressure treatment in obstructive sleep apnea and mortality associated with treatment failure - a national registry-based cohort study

OBJECTIVES

Adherence to continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA) is crucial. Our aim was to identify protective and risk factors against the discontinuation of CPAP treatment in patients with OSA and to estimate the mortality risk in those who were non-adherent to CPAP therapy.

METHODS

This was a registry-based cohort study from 37 centers across Sweden with OSA patients on CPAP in the Swedevox Swedish national registry between July 2010 and March 2017.

RESULTS

In 16,425 patients (70.8% men) with complete follow-up data after 1.2 ± 0.8 years the adjusted relative risk ratio (aRRR) for the discontinuation of CPAP was 0.57 (95% confidence interval (CI) 0.50-0.65) for use of humidifier, 0.87 (95% CI 0.82-0.92) for increasing age per 10 years, 0.80 (95% CI 0.77-0.83) for increasing apnea hypopnea index (AHI) per 5 units/hour, and 0.96 (95% CI 0.95-0.97) per increased unit on the Epworth Sleepiness Scale (ESS). Increasing BMI was associated with increased adherence up to BMI 35. Women and patients with hypertension ran an increased risk of discontinuing CPAP treatment, aRRR 1.28 (95% CI 1.12-1.46) and 1.24 (95% CI 1.12-1.42) respectively. The adjusted hazard ratio (HR) for mortality was 1.74 (95% CI 1.32-2.28) among those who did not adhere to CPAP (median follow-up period 2.4 years after the one year adherence evaluation).

CONCLUSION

Use of humidifier is associated with greater adherence to CPAP treatment. Other factors predicting adherence are increasing age, more severe OSA and overweight up to BMI 35, whereas female gender and coexisting hypertension are risk factors for discontinuation of CPAP. Failure to adhere to CPAP is associated with increased mortality.

Erickson solution-focused coaching for weight management in obese patients with obstructive sleep apnoea: ECOHEALTH pilot study

Coaching as a lifestyle modification approach to weight management is insufficiently explored in obstructive sleep apnoea. We investigated anthropometry and body composition after 20 weeks of Erickson coaching in 26 obstructive sleep apnoea patients (19 males; 47.6 ± 2.4 years). Body weight, neck circumference, waist-to-hip ratio and %body fat significantly decreased after 20 weeks. The mean weight loss was 5.2 per cent ± 1.0 per cent; 20 (77%) participants achieved target reduction of >3 per cent. Coaching session attendance (p = 0.006) and reaching personal goal related to physical performance (p = 0.044) were independently associated with weight loss (multiple regression model R² = 0.608, p < 0.001). Erickson solution-focused coaching supports adherence to healthy lifestyle and weight reduction in obstructive sleep apnoea.

Obesity metabolic and hormonal disorders associated with obstructive sleep apnea and their impact on the risk of cardiovascular events

OBJECTIVE

To analyze metabolic and hormonal disorders resulting from the association between obesity and obstructive sleep apnea (OSA) syndrome that predispose to cardiovascular diseases and investigate the clinical benefits obtained from treatment approaches for both conditions.

METHODS

A literature review between 1997 and 2017 was conducted in the PubMed search database.

RESULTS

Obesity is the most important risk factor for OSA, and the progressive increase in its prevalence also affects OSA incidence. In addition, OSA may aggravate weight gain and obesity comorbidities. Both conditions lead to an increase in the risk of cardiovascular events and mortality. The gold standard treatment for moderate to severe OSA is CPAP, but significant reduction in major cardiovascular events was not observed in clinical trials. Body weight reduction appears effective to improve OSA, as long as it is maintained. Lifestyle modifications and drug therapy seem to be the preferred approach to treat obesity, but in severe obesity and moderate to severe OSA, bariatric surgery is probably the most adequate treatment.

CONCLUSIONS

Weight control is essential to decrease the risk of cardiovascular events and mortality potentially linked to both obesity and OSA. CPAP seems to treat only OSA without decreasing these risks. Other treatment strategies are lifestyle modifications and drug therapy, which need further investigation as well as bariatric surgery for severe cases.

Abnormal Growth and Feeding Behavior in Upper Airway Obstruction in Rats

Pediatric obstructive sleep apnea (OSA) is a syndrome manifesting with snoring and increased respiratory effort due to increased upper airway resistance. In addition to cause the abnormal sleep, this syndrome has been shown to elicit either growth retardation or metabolic syndrome and obesity. Treating OSA by adenotonsillectomy is usually associated with increased risk for obesity, despite near complete restoration of breathing and sleep. However, the underlying mechanism linking upper airways obstruction (AO) to persistent change in food intake, metabolism, and growth remains unclear. Rodent models have examined the impact of intermittent hypoxia on metabolism. However, an additional defining feature of OSA that is not related to intermittent hypoxia is enhanced respiratory loading leading to increased respiratory effort and abnormal sleep. The focus of this mini review is on recent evidence indicating the persistent abnormalities in endocrine regulation of feeding and growth that are not fully restored by the chronic upper AO removal in rats. Here, we highlight important aspects related to abnormal regulation of metabolism that are not related to intermittent hypoxia per se, in an animal model that mimics many of the clinical features of pediatric OSA. Our evidence from the AO model indicates that obstruction removal may not be sufficient to prevent the post-removal tendency for abnormal growth.