Weight Loss Interventions as Treatment of Obesity Hypoventilation Syndrome. A Systematic Review

Long-term myocardial effects of noninvasive ventilation in patients with obesity hypoventilation syndrome

INTRODUCTION

Chronic effects of noninvasive ventilation on myocardial function in patients with obesity hypoventilation syndrome (OHS) are scarcely understood. The aim of the present study was to evaluate the long-term effects of volume-targeted bilevel positive airway pressure ventilation (BiPAP) on cardiac parameters and myocardial biomarkers in patients with OHS.

METHODS

Clinically stable patients with OHS referred to the tertiary center for the initiation of long-term BiPAP therapy were consecutively enrolled. At baseline, all participants underwent overnight cardiorespiratory polygraphy. BiPAP therapy using volume-targeted spontaneous/timed mode delivered via an oro-nasal mask was initiated. Beat-to-beat noninvasive monitoring by impedance cardiography was used to assess heart function at baseline and after 3 and 12 months of BiPAP use. Serum troponin 1, N-Terminal Pro-B-Type Natriuretic Peptide (NT-ProBNP), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) were monitored.

RESULTS

Thirteen patients (10 men; mean age, 55.8 ± 9.8 years; mean body mass index of 47.8 ± 5.9 kg/m2) were recruited. From baseline to 3, and to 12 months of BiPAP use, left ventricular stroke volume (SV), ejection time (LVET), and ejection time index significantly increased (P = 0.030; P < 0.001; P = 0.003, respectively), while heart rate and systolic time ratio significantly decreased (P = 0.004; P = 0.034, respectively). Reductions in serum NT-proBNP, IL-6 and TNF-α were observed (P = 0.045; P = 0.018; P = 0.003, respectively). No significant changes in serum troponin were detected throughout the study.

CONCLUSIONS

The present findings of increased SV, in association with lengthening of LVET, reductions of NT-proBNP and reductions in circulatory inflammatory markers in patients with stable OHS and chronic moderate-to-severe daytime hypercapnia treated with BiPAP over 1 year support the role of this therapeutic mode in such patients.

Update in Noninvasive Home Mechanical Ventilation: A Narrative Review of Indications, Outcomes, and Monitoring

Hypercapnic respiratory failure arises due to an imbalance in the load-capacity-drive relationship of the respiratory muscle pump, typically arising in patients with chronic obstructive pulmonary disease, obesity-related respiratory failure, and neuromuscular disease. Patients at risk of developing chronic respiratory failure and those with established disease should be referred to a specialist ventilation unit for evaluation and consideration of home noninvasive ventilation (NIV) initiation. Clinical trials demonstrate that, following careful patient selection, home NIV can improve a range of clinical, patient-reported, and physiological outcomes. This narrative review provides an overview of the pathophysiology of chronic respiratory failure, evidence-based applications of home NIV, and monitoring of patients established on home ventilation and describes technological advances in ventilation devices, interfaces, and monitoring to enhance comfort, promote long-term adherence, and optimise gas exchange.

Intermittent Versus Sustained Hypoxemia from Sleep-disordered Breathing: Outcomes in Patients with Chronic Lung Disease and High Altitude

In a variety of physiologic and pathologic states, people may experience both chronic sustained hypoxemia and intermittent hypoxemia ("combined" or "overlap" hypoxemia). In general, hypoxemia in such instances predicts a variety of maladaptive outcomes, including excess cardiovascular disease or mortality. However, hypoxemia may be one of the myriad phenotypic effects in such states, making it difficult to ascertain whether adverse outcomes are primarily driven by hypoxemia, and if so, whether these effects are due to intermittent versus sustained hypoxemia.

Targeting Hypercapnia in Chronic Lung Disease and Obesity Hypoventilation: Benefits and Challenges

Hypoventilation is a complication that is not uncommon in chronic obstructive pulmonary disease and calls for both medical treatment of the underlying disease and, frequently, noninvasive ventilation either during exacerbations requiring hospitalization or in a chronic state in the patient at home. Obesity hypoventilation syndrome by definition is associated with ventilatory failure and hypercapnia. It may or may not be accompanied by obstructive sleep apnea, which when detected becomes an additional target for positive airway pressure treatment. Intensive research has not completely resolved the best choice of treatment, and the simplest modality, continuous positive airway pressure, may still be entertained.

Obstructive Sleep Apnea, Obesity Hypoventilation Syndrome, and Pulmonary Hypertension: A State-of-the-Art Review

The pathophysiological interplay between sleep-disordered breathing (SDB) and pulmonary hypertension (PH) is complex and can involve a variety of mechanisms by which SDB can worsen PH. These mechanistic pathways include wide swings in intrathoracic pressure while breathing against an occluded upper airway, intermittent and/or sustained hypoxemia, acute and/or chronic hypercapnia, and obesity. In this review, we discuss how the downstream consequences of SDB can adversely impact PH, the challenges in accurately diagnosing and classifying PH in the severely obese, and review the limited literature assessing the effect of treating obesity, obstructive sleep apnea, and obesity hypoventilation syndrome on PH.

Impact of treating obesity hypoventilation syndrome on body mass index

STUDY OBJECTIVES

To evaluate the impact of positive airway pressure (PAP) therapy on body mass index (BMI) in patients with obesity hypoventilation syndrome (OHS) associated with obstructive sleep apnea (OSA).

METHODS

A systematic review using the following terms: "obesity hypoventilation syndrome" AND "treatment" AND "randomized" using Cochrane Central Register of Controlled Trials, Medline and Web of Science was performed from the first data available until February 10, 2023. The inclusion criteria were: (1) original article; (2) adult OHS with concomitant OSA (apnea-hypopnea index or AHI ≥5 events/h); (3) randomized trial with PAP arm and standard care (control); (4) BMI evaluation at baseline and after the first months. We performed an individual participant data meta-analysis of randomized controlled trials.

RESULTS

Our initial search retrieved 32 articles and 3 randomized studies fulfilled study criteria and were included in the final analysis, leading to a total of 342 participants. Patients were predominantly females (62%) and had OHS associated with at least mild OSA. As compared to baseline, a decrease in BMI was observed at study endpoint but this difference was not different intergroups (-0.50 ± 1.49 and -0.50 ±1.83, in control and PAP groups respectively (p=0.939)). Weight change was not associate with PAP adherence, OSA severity or use of supplemental oxygen.

CONCLUSIONS

In contrast to treatment of eucapnic OSA with PAP that is associated with weight gain, treatment of OSA+OHS patients with or without PAP is associated with weight loss. Future studies are necessary to elucidate the mechanism by which weight loss occurs.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Profiles of Elderly Patients with Obesity Hypoventilation Syndrome in Martinique: A Single-Center Study

Obesity hypoventilation syndrome (OHS) is a form of chronic respiratory insufficiency related to obesity that affects young and old people. Age appears to be associated with poorer response to treatment by nighttime ventilation. This study aimed to describe the characteristics of elderly subjects (>65 years) with OHS compared to younger patients, with a view to adapting therapy in older individuals. We conducted a retrospective study comparing socio-demographic, clinical, functional characteristics as well as treatment and outcomes between young (<65 years) and older (65 years and older) individuals with OHS at the University Hospital of Martinique. We included 143 patients (114 women), of whom 82 were 65 years or older (57%). Charlson index was higher in the older group. Patients in ≥65 years group were less frequently obese, but more frequently had diabetes mellitus, cardiac arrythmia and arterial hypertension compared to younger patients. There was no difference in the circumstances of diagnosis or arterial blood gas at diagnosis. At follow up, partial pressure of carbon dioxide (pCO₂) was higher in ≥65 years group. Despite comparable NIV settings, apart from lower expiratory positive airway pressure (EPAP) with higher apnea-hypopnea index (AHI), patients in the ≥65-year-old group remained more frequently hypercapnic. In conclusion, over half (57%) of patients with OHS in our cohort were aged over 65 years. Older patients developed OHS at lower BMI levels than their younger counterparts, and more frequently, had comorbidities such as diabetes, hypertension and cardiac arrhythmia. Increased Charlson index, lower BMI and female sex were independent factors associated with OHS in the elderly.

Comparing the influence of foot reflexology and fasting mimicking diet on quality of life and sleep quality in obesity hypoventilation syndrome

OBJECTIVES

Obesity hypoventilation syndrome is one of the most serious outcomes of obesity-related respiratory difficulties, resulting in higher healthcare costs as well as increased cardio-respiratory morbidity and mortality.

METHODS

Sixty-two males who had a high risk of obstructive sleep apnea according to the STOP-BANG Sleep Apnea Questionnaire were enrolled in the study. Their age is 50-60 years old, and they have a BMI of 35-40 kg/m², daytime hypercapnia, and sleep breathing problems. The patients were divided into two equal groups at random reflexology fasting-mimicking diet groups. Weight, height, waist, and neck circumference were assessed at the beginning of the study and after two months of the intervention. Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI), which is used to evaluate sleep quality. The Maugeri Obstructive Sleep Apnea Syndrome (MOSAS) questionnaire was used to assess a patient's quality of life.

RESULTS

There was a significant change in the MOSAS and PSQI questionnaires for both groups post-intervention, as the p-value was less than 0.05. The percentage change in the MOSAS questionnaire score and PSQI questionnaire was higher in the mimic diet group than in the reflexology group. Also, the mimic diet group's weight and neck circumference were considerably reduced after the intervention, with no change in the reflexology group.

CONCLUSIONS

Reflexology and a fasting-mimicking diet were found to have a substantial impact on enhancing the quality of life and sleep in people with obesity hypoventilation syndrome.

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.

EFFECTS OF DIEP FLAP-BASED BREAST RECONSTRUCTION ON RESPIRATORY FUNCTION

BACKGROUND

Breast reconstruction (BR) is an essential part of breast cancer treatment, and the DIEP flap is considered the gold standard reconstruction technique, which uses a free abdominal flap. Concerns have been raised regarding the effects of abdominoplasty on respiratory functions. This topic has not been addressed regarding donor-site closure of DIEP flaps. Our aim is to prospectively compare preoperative and postoperative spirometry in patients undergoing DIEP flap-based BR, investigating its impact on respiratory function.

MATERIALS AND METHODS

We enrolled 21 patients who received BR with DIEP flap in our institution, who underwent pulmonary function assessment by spirometry 1 month preoperatively and 1 year postoperatively. We assessed Forced Expiratory Volume in the first second (FEV1), Forced Vital Capacity (FVC), FEV1/FVC ratio, and Peak Expiratory Flow (PEF). Statistical analysis was performed using the paired samples test.

RESULTS

An improvement in the mean values of all 4 variables was found at 1 year from surgery. Namely, FEV1 improved by 0.1 L with a standard deviation (SD) of 0.39 L, FVC by 0.04 L with SD of 0.627, FEV1/FVC by 2.11 L with SD of 7.85 L, and PEF by 1.2 L with SD of 1.45 L. Only PEF was statistically significant [P = 0.001].

CONCLUSION

Our results suggest that DIEP flap BR does not negatively impact respiratory function. Although further knowledge is required, we confirm the possibility of considering the indication for abdominoplasty and DIEP flap reconstruction in patients with altered and reduced pulmonary function.

Obesity-associated sleep hypoventilation and increased adverse postoperative bariatric surgery outcomes in a large clinical retrospective cohort

STUDY OBJECTIVES

Although obesity hypoventilation syndrome (OHS) is associated with increased morbidity and mortality, post-bariatric surgery OHS risk remains unclear due to often nonsystematic OHS assessments.

METHODS

We leverage a clinical cohort with nocturnal CO2 monitoring during polysomnography to address the hypothesis that patients with obesity-associated sleep hypoventilation (OaSH; ie, stage II OHS) have increased adverse postoperative bariatric surgery outcomes. We retrospectively analyzed data from patients undergoing pre-bariatric surgery polysomnography at the Cleveland Clinic from 2011-2018. OaSH was defined by body mass index ≥ 30 kg/m2 and either polysomnography-based end-tidal CO2 ≥ 45 mmHg or serum bicarbonate ≥ 27 mEq/L. Outcomes considered were as follows: intensive care unit stay, intubation, tracheostomy, discharge disposition other than home or 30-day readmission individually and as a composite, and all-cause mortality. Two-sample t test or Wilcoxon rank-sum test for continuous variables and chi-square or Fisher's exact test for categorical variables were used for OaSH vs non-OaSH comparisons. All-cause mortality was compared using Kaplan-Meier estimation and Cox proportional hazards models.

RESULTS

The analytic sample (n = 1,665) was aged 45.2 ± 12 years, 20.4% were male, had a body mass index of 48.7 ± 9 kg/m2, and 63.6% were White. OaSH prevalence was 68.5%. OaSH patients were older and more likely to be male with a higher BMI, apnea-hypopnea index, and glycated hemoglobin. The composite outcome was higher in OaSH vs non-OaSH patients (18.9% vs 14.3%, P = .021). Although some individual outcomes were respectively higher in OaSH vs non-OaSH patients, differences were not statistically significant: intubation (1.5% vs 1.3%, P = .81) and 30-day readmission (13.8% vs 11.3%, P = .16). Long-term mortality (median follow-up: 22.9 months) was not significantly different between groups, likely due to overall low event rate (hazard ratio = 1.39, 95% confidence interval: 0.56, 3.42).

CONCLUSIONS

In this largest sample to date of systematically phenotyped OaSH in a bariatric surgery cohort, we identify increased postoperative morbidity in those with sleep-related hypoventilation in stage II OHS when a composite outcome was considered, but individual contributors of intubation, intensive care unit admission, and hospital length of stay were not increased. Further study is needed to identify whether perioperative treatment of OaSH improves post-bariatric surgery outcomes.

CITATION

Chindamporn P, Wang L, Bena J, et al. Obesity-associated sleep hypoventilation and increased adverse postoperative bariatric surgery outcomes in a large clinical retrospective cohort. J Clin Sleep Med. 2022;18(12):2793-2801.

A Clinical Encounter With Pickwickian Syndrome

The clinical syndrome described in the literature as "Pickwickian syndrome" is characterized by a combination of sleep-disordered breathing, obesity, and daytime hypercapnia; the condition is also known as obesity hypoventilation syndrome (OHS). This syndrome is a diagnosis of exclusion after every other possible etiology is ruled out. Patients can present both with an exacerbation of or a chronic state of progressive dyspnea. In this report, we describe the case of a 62-year-old morbidly obese female with a BMI of 42 Kg/m², who presented with progressively worsening breathlessness. An arterial blood gas (ABG) analysis revealed severe hypoxia with hypercarbia. A sleep study [polysomnography (PSG)] of the patient was performed, which revealed an apnea-hypopnea index (AHI) of 58.2, and the patient was diagnosed as having OHS after all other possible cardiorespiratory etiologies were ruled out. The patient was promptly managed with non-invasive ventilatory (NIV) support along with supportive management and was prescribed overnight NIV and subsequently discharged in stable condition.

Obesity Hypoventilation Syndrome and Postsurgical Outcomes in a Bariatric Surgery Cohort

Purpose

Patients with obesity and elevated serum bicarbonate suggesting obesity hypoventilation syndrome (OHS) undergoing bariatric surgery may represent a unique subgroup. Information regarding surgical outcomes in this population remains limited. We sought to test the hypothesis that an elevated bicarbonate would be an important predictor of perioperative complications (i.e., length of hospital stay) and postsurgical outcomes (i.e., weight loss at 1 year).

Materials and Methods

Consecutive patients undergoing bariatric surgery between January 2015 and December 2018 were included. Patients with a preoperative serum bicarbonate ≥ 27 mEq/L were classified as suspected OHS.

Results

Of 297 patients, the prevalence of suspected OHS based on an elevated bicarbonate was 19.5% (95% CI: 15.3 to 24.6%). Length of hospital stay was similar in the suspected OHS and non-OHS control group (1.50 vs 1.49 days, P = 0.98). The achieved weight loss from peak preoperative weight to 1 year post-surgery was less in the suspected OHS vs the control group (4.2% [95% CI 1.6 to 6.8]; P = 0.002).

Conclusion

Patients with serum bicarbonate ≥ 27 mEq/L as a surrogate marker for OHS experienced weight loss that was significantly less than their normal serum bicarbonate counterparts, but still achieved weight loss deemed clinically important by current guidelines. We observed no significant difference in length of hospital stay at time of surgery.

Graphical abstract

Cardiovascular disease in obesity hypoventilation syndrome - A review of potential mechanisms and effects of therapy

Cardiovascular disease is common in patients with obesity hypoventilation syndrome (OHS) and accounts in part for their poor prognosis. This narrative review article examines the epidemiology of cardiovascular disease in obesity hypoventilation syndrome, explores possible contributing factors and the effects of therapy. All studies that included cardiovascular outcomes and biomarkers were included. Overall, there is a higher burden of cardiovascular disease and cardiovascular risk factors among patients with obesity hypoventilation syndrome. In addition to obesity and sleep-disordered breathing, there are several other pathophysiological mechanisms that contribute to higher cardiovascular morbidity and mortality in OHS. There is evidence emerging that positive airway pressure therapy and weight loss have beneficial effects on the cardiovascular system in obesity hypoventilation syndrome patients, but further research is needed to clarify whether this translates to clinically important outcomes.

Case report: fast reversal of malignant obesity hypoventilation syndrome after noninvasive ventilation and pulmonary rehabilitation

Background

Malignant obesity hypoventilation syndrome (MOHS) is described as a subtype condition of OHS, characterized by extreme obesity, obese-related hypoventilation, and multiorgan dysfunction. Because of low awareness and inadequate treatment, MOHS leads to high morbidity and mortality.

Case presentation

A 53-year-old man was diagnosed with MOHS evidenced by extreme obesity and multiorgan abnormalities. After taken noninvasive ventilation (NIV) treatment, he was rescued. And at the end of the six-month pulmonary rehabilitation (PR) program, improvement in terms of respiratory parameters, BMI, apnea-hypopnea index (AHI), and pulmonary hypertension were observed in the patient. Two years later, the patient was still in good condition.

Conclusions

This case highlights the awareness and proper use of NIV to rescue MOHS patients. Furthermore, the benefits of PR were explored in this case, which has not been considered within the therapeutic options for MOHS patients.

Contemporary Concise Review 2020: Sleep

Obstructive sleep apnoea (OSA) now affects one-seventh of the world's population. Treatment of even mild OSA can improve daytime sleepiness and quality of life. Recent modifications to uvulopalatopharyngoplasty may make it a more widely applicable treatment option in selected patients with OSA. Diet and exercise have effects on sleep apnoea severity independent of weight loss. Insomnia has become increasingly common during the coronavirus disease 2019 (COVID-19) pandemic.

Adherence to Positive Airway Pressure Therapy in Obesity Hypoventilation Syndrome

Because of the prevalence of extreme obesity in the United States, there has been an increase in prevalence of obesity hypoventilation syndrome (OHS). There is limited information on the characteristics and pattern of positive airway pressure (PAP) adherence in patients with OHS compared with eucapnic patients with obstructive sleep apnea (OSA). This article discusses in detail the impact of PAP therapy on outcomes in patients with OHS, compares adherence between continuous PAP and noninvasive ventilation in OHS, and compares PAP adherence in patients with OHS to patients with moderate to severe OSA enrolled in clinical trials designed to improve CPAP adherence.

Effectiveness of different treatments in obesity hypoventilation syndrome

Obesity hypoventilation syndrome (OHS) is an undesirable consequence of obesity, defined as daytime hypoventilation, sleep disorder breathing and obesity; during the past few years the prevalence of extreme obesity has markedly increased worldwide consequently increasing the prevalence of OHS. Patients with OHS have a lower quality of life and a higher risk of unfavourable cardiometabolic consequences. Early diagnosis and effective treatment can lead to significant improvement in patient outcomes; therefore, such data has noticeably raised interest in the management and treatment of this sleep disorder. This paper will discuss the findings on the main current treatment modalities OHS will be discussed.