Effects of laparoscopic adjustable gastric banding on sleep and metabolism: a 12-month follow-up study

The efficacy of bariatric surgery on pulmonary function and sleep architecture of patients with obstructive sleep apnea and co-morbid obesity: a systematic review and meta-analysis

Obstructive sleep apnea (OSA) is highly prevalent in patients with morbid obesity. There is a growing interest in the role of bariatric surgery in OSA management. This study aims to evaluate the therapeutic efficacy of bariatric surgery on changes in pulmonary function and sleep architecture. Studies of patients with OSA that underwent bariatric surgery were searched in 4 different databases (PubMed, Cochrane, Web of Science, and Embase) until October 31, 2022. We identified studies evaluating the efficacy of surgical intervention on primary outcomes (body mass index [BMI] and apnea-hypopnea index [AHI]) and secondary outcomes such as forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC, oxygen desaturation index (ODI), T90, mean oxygen saturation (SpO2), nadirSpO2, sleep efficiency (SE), N1%, N2%, N3%, rapid eye movement (REM%), arousal index, Epworth sleepiness scale (ESS), neck circumference, waist circumference, and weight. A total of 24 eligible studies were finally chosen. Risk of bias assessed through funnel plots was collected and analyzed via random effects meta-analyses. There were significant reductions in BMI and AHI after bariatric surgery induced weight loss. Accordingly, improvement in FVC, meanSpO2, nadirSpO2, SE, N3%, REM%, and ESS were observed compared with baseline. Patients with OSA also exhibit lower ODI, T90, arousal index, neck circumference, waist circumference, and weight after treatment. Bariatric surgery has beneficial effects on patients with OSA and obesity, particularly with morbid obesity. Surgical weight loss significantly eliminates apnea-hypopnea events, reduces weight, increases oxygen saturation, N3 and REM sleep stage, reduces sleep fragmentation, and improves pulmonary functions with augmented FVC.

Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment

INTRODUCTION

This systematic review provides supporting evidence for the accompanying clinical practice guideline on the referral of adults with obstructive sleep apnea (OSA) for surgical consultation.

METHODS

The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies that compared the use of upper airway sleep apnea surgery or bariatric surgery to no treatment as well as studies that reported on patient-important and physiologic outcomes pre- and postoperatively. Statistical analyses were performed to determine the clinical significance of using surgery to treat obstructive sleep apnea in adults. Finally, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process was used to assess the evidence for making recommendations.

RESULTS

The literature search resulted in 274 studies that provided data suitable for statistical analyses. The analyses demonstrated that surgery as a rescue therapy results in a clinically significant reduction in excessive sleepiness, snoring, blood pressure (BP), apnea-hypopnea index (AHI), respiratory disturbance index (RDI), and oxygen desaturation index (ODI); an increase in lowest oxygen saturation (LSAT) and sleep quality; and an improvement in quality of life in adults with OSA who are intolerant or unaccepting of positive airway pressure (PAP) therapy. The analyses demonstrated that surgery as an adjunctive therapy results in a clinically significant reduction in optimal PAP pressure and improvement in PAP adherence in adults with OSA who are intolerant or unaccepting of PAP due to side effects associated with high pressure requirements. The analyses also demonstrated that surgery as an initial treatment results in a clinically significant reduction in AHI/RDI, sleepiness, snoring, BP, and ODI and an increase in LSAT in adults with OSA and major anatomical obstruction. Analysis of bariatric surgery data showed a clinically significant reduction in BP, AHI/RDI, sleepiness, snoring, optimal PAP level, BMI, and ODI and an increase in LSAT in adults with OSA and obesity. Analyses of very limited evidence suggested that upper airway surgery does not result in a clinically significant increase in risk of serious persistent adverse events and suggested that bariatric surgery may result in a clinically significant risk of iron malabsorption that may be managed with iron supplements. The task force provided a detailed summary of the evidence along with the quality of evidence, the balance of benefits and harms, patient values and preferences, and resource use considerations.

CITATION

Kent D, Stanley J, Aurora RN, et al. Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2021;17(12):2507-2531.

The immune remodel: Weight loss-mediated inflammatory changes to obesity

Obesity is an escalating world problem that contributes to the complexity and cost of treatment of metabolic disorders. Obesity is the result of increased storage of energy in the form of adipose tissue, reducing the quality of daily life, and interfering with longevity. Obesity is also a chronic, low-grade inflammatory disorder. The inflammatory processes affect many organ systems with expanded numbers of immune cells and increased cytokine production. Long-term weight loss is difficult to achieve and maintain. Lifestyle modifications, pharmacologic treatments, and surgical methods are increasingly utilized to ameliorate excess body weight and the comorbidities of obesity, such as diabetes, cardiovascular disease, dyslipidemia, and cancers. Weight loss is also touted to reduce inflammation. Here we review the current literature on human obesity-related systemic and local changes to the immune system and circulating inflammatory mediators. Further, we consider the impact of weight loss to reduce the burden of inflammation, bearing in mind the different methods of weight loss—behavioral change vs. surgical intervention.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Fasting ghrelin levels after gastric bypass and vertical sleeve gastrectomy: An analytic cohort study

BACKGROUND AND OBJECTIVE

Neuronal populations involved in the regulation of food intake, particularly the orexigenic (appetite-stimulating) hormone ghrelin, are found in the hypothalamus. Changes in plasma ghrelin levels have been observed following different bariatric surgery procedures, but the results from different studies are contradictory. Much remains unknown regarding the role of ghrelin in the weight loss process following bariatric surgery. Our objective was to describe the behaviour of fasting ghrelin levels, comparing the changes occurring between 2 different surgical techniques (gastric bypass versus vertical sleeve gastrectomy) and their correlation with weight loss.

PATIENTS AND METHOD

A prospective, observational, analytic cohort study of 54 patients (27 for each surgical technique) with a 12-month follow-up period. We analysed demographic data, anthropometric data, comorbidities, weight loss and evolution of fasting ghrelin.

RESULTS

The behaviour of acylated ghrelin was similar with the 2 surgical techniques, with no significant differences between gastric bypass and vertical sleeve gastrectomy. With both procedures, there was an increase in acylated ghrelin on day 5 and a subsequent decrease, and levels then gradually increased to reach values at 12 months that were higher than those reported preoperatively. This increase in ghrelin levels did not affect weight loss, since one year post-surgery, 30% weight loss was achieved with both types of surgery.

CONCLUSIONS

We observed an increase in fasting acylated ghrelin levels at one year of follow-up with both surgical techniques, with 30% weight loss.

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

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

Neuroendocrine regulation of energy balance: Implications on the development and surgical treatment of obesity

INTRODUCTION

Obesity, a serious public health problem, occurs mainly when food consumption exceeds energy expenditure. Therefore, energy balance depends on the regulation of the hunger-satiety mechanism, which involves interconnection of the central nervous system and peripheral signals from the adipose tissue, pancreas and gastrointestinal tract, generating responses in short-term food intake and long-term energy balance. Increased body fat alters the gut- and adipose-tissue-derived hormone signaling, which promotes modifications in appetite-regulating hormones, decreasing satiety and increasing hunger senses. With the failure of conventional weight loss interventions (dietary treatment, exercise, drugs and lifestyle modifications), bariatric surgeries are well-accepted tools for the treatment of severe obesity, with long-term and sustained weight loss. Bariatric surgeries may cause weight loss due to restriction/malabsorption of nutrients from the anatomical alteration of the gastrointestinal tract that decreases energy intake, but also by other physiological factors associated with better results of the surgical procedure.

OBJECTIVE

This review discusses the neuroendocrine regulation of energy balance, with description of the predominant hormones and peptides involved in the control of energy balance in obesity and all currently available bariatric surgeries.

CONCLUSIONS

According to the findings of our review, bariatric surgeries promote effective and sustained weight loss not only by reducing calorie intake, but also by precipitating changes in appetite control, satiation and satiety, and physiological changes in gut-, neuro- and adipose-tissue-derived hormone signaling.

Comparing the Excessive Daytime Sleepiness of Obese and Non-obese Patients

BACKGROUND

Obesity, particularly morbid obesity, has various physical and mental complications. Excessive daytime somnolence (EDS) is a sleep disorder that reduces individuals' performance capability and the accuracy of their short-term memory and causes learning problems. This retrospective study aimed to document the presence of EDS in a sample of obese patients in comparison to patients with a normal weight.

OBJECTIVES

This article compares the excessive daytime sleepiness of obese and non-obese patients in the minimally invasive surgery research center in Tehran, Iran.

PATIENTS AND METHODS

In this case-control study, we compared excessive daytime sleepiness in 55 obese patients who were candidates for laparoscopic surgery, with a body mass index (BMI) of equal to or greater than 30 kg/ m2, with 55 controls with a normal BMI (19.5 - 24.9 kg/ m2). The process of selecting the control group in our case-control study is matching in group levels, so that the controls are similar to the case group with regard to certain key characteristics, such as age, sex, and race. The sleep assessment was based on the Epworth sleepiness scale (ESS) questionnaire. Analysis of variance (ANOVA) was used to compare the means of quantitative data, such as the ESS score of groups.

RESULTS

Sleepiness was not affected by gender in cases or controls. The sleepiness prevalence was 29 (52.7%) in the cases group and 17 (30.9%) in the control group (OR = 2.493 (95% CI 1.144 -5.435)). The mean ESS scores in cases and controls were 7.82 ± 3.86 and 10.54 ± 6.15, respectively (P = 0.007). Moreover, the prevalence of sleepiness and the mean ESS scores in class III of obesity differed significantly from the controls (16 (57.1%) vs. 17 (30.9%)) (OR = 2.980 (95% CI 1.162 - 7.645)) and (11.04 ± 5.93 vs. 7.82 ± 3.86) (P = 0.013), respectively.

CONCLUSIONS

Our findings suggest a strong relationship between EDS and obesity, particularly morbid obesity. Therefore, physicians must be familiar with EDS as a mixed clinical entity indicating careful assessment and specific treatment planning.

Effect of Laparoscopic Roux-en-Y Gastric Bypass Surgery on Obstructive Sleep Apnea in a Chinese Population with Obesity and T2DM

Background

Bariatric surgery has been reported to be an effective treatment for obstructive sleep apnea (OSA). However, this evidence was not enough for different populations. Thus, we conducted a follow-up study to evaluate the effect of bariatric surgery on OSA in a Chinese population with obesity and type 2 diabetes mellitus (T2DM).

Methods

From May 2011 to March 2014, 72 consecutive subjects with obesity and T2DM were recruited for this study. Before and at least 6 months after the laparoscopic Roux-en-Y gastric bypass (LYGB) surgery, all subjects were asked to undergo a polysomnography test. During the sleep center visit, anthropometric characteristic data, blood samples, and sleep questionnaires were collected.

Results

In total, 44 Chinese participants with OSA were included in the study. Compared with baseline data, the postoperative anthropometric characteristics, blood measurements, and sleep recording data, such as weight, apnea hypopnea index (AHI), and insulin resistance index, differed significantly (p < 0.001). The change in AHI was correlated significantly with preoperative weight (r = 0.298, p < 0.05), preoperative AHI (r = 0.729, p < 0.001), preoperative waist circumference (r = 0.307, p < 0.05), and preoperative insulin resistance (IR) index (r = −0.301, p < 0.05). Postoperative AHI was correlated significantly with age (r = 0.039, p = 0.039) and preoperative AHI (r = 0.445, p = 0.002), and the following prediction model was generated: log₁₀ (postoperative AHI) = 0.626 × log₁₀ (preoperative AHI) +0.010 × age −0.581.

Conclusions

Our findings indicate that LYGB could be an effective therapeutic intervention in the management of OSA for patients with both obesity and T2DM, and the preoperative AHI and age might be important factors that influence the effort of LYGB.

Electronic supplementary material

The online version of this article (doi:10.1007/s11695-014-1510-9) contains supplementary material, which is available to authorized users.

Role of gastrointestinal hormones in feeding behavior and obesity treatment

Food intake regulation is generally evaluated by many aspects consisting of complex mechanisms, including homeostatic regulatory mechanism, which is based on negative feedback, and hedonic regulatory mechanism, which is driven by a reward system. One important aspect of food intake regulation is the peripheral hormones that are secreted from the gastrointestinal tract. These hormones are secreted from enteroendocrine cells as feedback to nutrient and energy intake, and will communicate with the brain directly or via the vagus nerve. Gastrointestinal hormones are very crucial in maintaining a steady body weight, despite variations in nutrient intake and energy expenditure. In this review, we provide an overview of the regulation of feeding behavior by gut hormones, and its role in obesity treatments.

Peripheral signals mediate the beneficial effects of gastric surgery in obesity

Obesity is nowadays a public health problem both in the industrialized world and developing countries. The different treatments to fight against obesity are not very successful with the exception of gastric surgery. The mechanism behind the achievement of this procedure remains unclear although the modifications in the pattern of gastrointestinal hormones production appear to be responsible for the beneficial effect. The gastrointestinal tract has emerged in the last time as an endocrine organ in charge of response to the different stimulus related to nutritional status by the modulation of more than 30 signals acting at central level to modulate food intake and body weight. The production of some of these gastric derived signals has been proved to be altered in obesity (ghrelin, CCK, and GLP-1). In fact, bariatric surgery modifies the production of both gastrointestinal and adipose tissue peripheral signals beyond the gut microbiota composition. Through this paper the main peripheral signals altered in obesity will be reviewed together with their modifications after bariatric surgery.

Metabolic surgery: action via hormonal milieu changes, changes in bile acids or gut microbiota? A summary of the literature

Obesity and type 2 diabetes remain epidemic problems. Different bariatric surgical techniques causes weight loss and diabetes remission to varying degrees. The underlying mechanisms of the beneficial effects of bariatric surgery are complex, and include changes in diet and behaviour, as well as changes in hormones, bile acid flow, and gut bacteria. We summarized the effects of multiple different bariatric procedures, and their resulting effects on several hormones (leptin, ghrelin, adiponectin, glucagon-like peptide 1 (GLP-1), peptide YY, and glucagon), bile acid changes in the gut and the serum, and resulting changes to the gut microbiome. As much as possible, we have tried to incorporate multiple studies to try to explain underlying mechanistic changes. What emerges from the data is a picture of clear differences between restrictive and metabolic procedures. The latter, in particular the roux-en-Y gastric bypass, induces large and distinctive changes in most measured fat and gut hormones, including early and sustained increase in GLP-1, possible through intestinal bile acid signalling. The changes in bile flow and the gut microbiome are causally inseparable so far, but new studies show that each contributes to the effects of weight loss and diabetes resolution.