The beneficial effect of weight reduction on adverse cardiovascular outcomes following bariatric surgery is attenuated in patients with obstructive sleep apnea

Established and potential cardiovascular risk factors in metabolic syndrome: Effect of bariatric surgery

PURPOSE OF REVIEW

The aim of this review was to provide an overview of the role of novel biomarkers in metabolic syndrome, their association with cardiovascular risk and the impact of bariatric surgery on these biomarkers.

RECENT FINDINGS

Metabolic syndrome encompasses an intricate network of health problems, and its constituents extend beyond the components of its operational definition. Obesity-related dyslipidaemia not only leads to quantitative changes in lipoprotein concentration but also alteration in qualitative composition of various lipoprotein subfractions, including HDL particles, rendering them proatherogenic. This is compounded by the concurrent existence of obstructive sleep apnoea (OSA) and nonalcoholic fatty liver disease (NAFLD), which pave the common pathway to inflammation and oxidative stress culminating in heightened atherosclerotic cardiovascular disease (ASCVD) risk. Bariatric surgery is an exceptional modality to reverse both conventional and less recognised aspects of metabolic syndrome. It reduces the burden of atherosclerosis by ameliorating the impact of obesity and its related complications (OSA, NAFLD) on quantitative and qualitative composition of lipoproteins, ultimately improving endothelial function and cardiovascular morbidity and mortality.

SUMMARY

Several novel biomarkers, which are not traditionally considered as components of metabolic syndrome play a crucial role in determining ASCVD risk in metabolic syndrome. Due to their independent association with ASCVD, it is imperative that these are addressed. Bariatric surgery is a widely recognized intervention to improve the conventional risk factors associated with metabolic syndrome; however, it also serves as an effective treatment to optimize novel biomarkers.

Peri- and Postoperative Outcomes for Obstructive Sleep Apnoea Patients after Bariatric Surgery-a Systematic Review and Meta-analysis

BACKGROUND

Obstructive sleep apnoea (OSA) is prevalent among patients undergoing bariatric surgery. Previous studies have reported a higher risk of complications, ICU admission and longer length of stay in patients with OSA following surgery. However, clinical outcomes following bariatric surgery are unclear. The hypothesis is that patients with OSA will have an increased risk of these outcome measures after bariatric surgery.

METHODS

A systematic review and meta-analysis were performed to answer the research question. Searches for bariatric surgery and obstructive sleep apnoea were performed using PubMed and Ovid Medline. Studies which compared OSA and non-OSA patients undergoing bariatric surgery and used outcome measures that included length of stay, risk of complications, 30-day readmission and need for ICU admission were selected for the systematic review. Comparable datasets from these studies were used for the meta-analysis.

RESULTS

Patients with OSA are at greater risk of complications after bariatric surgery (RR = 1.23 [CI: 1.01, 1.5], P = 0.04), driven mostly by an increased risk of cardiac complications (RR = 2.44 [CI: 1.26, 4.76], P = 0.009). There were no significant differences between the OSA and non-OSA cohorts in the other outcome variables (respiratory complications, length of stay, 30-day readmission and need for ICU admission).

CONCLUSION

Following bariatric surgery, patients with OSA must be managed carefully due to the increased risk of cardiac complications. However, patients with OSA are not more likely to require a longer length of stay or readmission.

Combined Airway and Bariatric Surgery (CABS) for Obstructive Sleep Apnea Patients with Morbid Obesity: A Comprehensive Alternative Preliminary Study

Although continuous positive airway pressure is the gold standard for obstructive sleep apnea (OSA), it does not improve obesity. By contrast, bariatric surgery significantly improves obesity but with sustained OSA in the majority of patients. This study proposes a comprehensive technique—combined airway and bariatric surgery (CABS)—to improve both obesity and OSA. The aims of the study are to evaluate the feasibility, safety and efficacy of CABS in morbidly obese OSA patients. The retrospective study enrolled 20 morbidly obese OSA patients (13 males; median age, 44 years; median apnea−hypopnea index (AHI), 63.2 event/h; median body mass index (BMI), 41.4 kg/m2). The study population was divided into two groups based on patients’ volition after shared decision making. The bariatric surgery (BS) group included laparoscopic sleeve gastrectomy (LSG, n = 8) and laparoscopic Roux-en-Y gastric bypass (LRYGB, n = 2). CABS involved bariatric surgery—LSG (n = 8) and LRYGB (n = 2) in conjunction with airway surgery (concurrent nasal/palatal/lingual surgery [n = 8], concurrent palatal/lingual surgery [n = 2]). Patients received a home sleep apnea test at baseline and one year after surgery. The two patient groups were not different in age, sex, preoperative AHI or preoperative BMI. There was no airway compromise, wound bleeding or infection throughout the postoperative period. One year after surgery, patients in both groups achieved significant improvement in AHI and BMI. Furthermore, the improvement in AHI was significantly higher (p = 0.04) in the CABS group than in the BS group despite the insignificant change in BMI reduction (p = 0.63) between the two groups. In the CABS group, the BMI dropped from 40.4 to 28.4 kg/m2 (p < 0.0001) and the AHI decreased from 75.1 to 4.5 event/h (p = 0.0004). The classic success rate for OSA was 90% and the cure rate was 60% in the CABS group. A perioperative assessment of CABS group patients also revealed a significant improvement in the Epworth sleepiness scale, minimal O2 saturation, snoring index and heart rate. CABS is feasible and safe in treating OSA with morbid obesity. CABS achieves more reduction in AHI than BS alone with high success and cure rates for OSA. CABS can also significantly improve quality of life and general health and offers a comprehensive alternative for morbidly obese OSA patients.

The effects of doxapram on time to tracheal extubation and early recovery in young morbidly obese patients scheduled for bariatric surgery: A randomised controlled trial

BACKGROUND

Bariatric surgery is a well established treatment of the obese. Postoperative respiratory failure and airway obstruction after bariatric surgery can often be attributed to the residual depressant effects of anaesthetics, sedatives and opioids. Peri-operative management of morbidly obese patients is still a concern for operating room professionals.

OBJECTIVE

The evaluation of the effects of doxapram on the outcomes of general anaesthesia following bariatric surgical procedures in the morbidly obese.

DESIGN

A single-blind randomised controlled trial with two parallel arms.

SETTING

A tertiary care teaching hospital, Tehran, Iran, from 2017 to 2018.

PARTICIPANTS

In total, 100 patients (69 women) with at least class two obesity were included in two groups of equal sizes and underwent bariatric surgery.

MAIN OUTCOME MEASURES

The primary outcome was the time from the administration of doxapram to tracheal extubation. Secondary outcomes included vital signs and variables including peak expiratory flow rate, time to return to spontaneous breathing, time to eye-opening and hand-squeezing on the commands, and time to recovery.

INTERVENTIONS

Both groups underwent general anaesthesia. The intervention group received a single dose of doxapram 1 mg kg ideal body weight, immediately after reversal of neuromuscular blockade and after discontinuation of all anaesthetics.

RESULTS

Doxapram decreased time to extubation, time to eye-opening and hand-squeezing, shortened recovery time and lowered end-tidal CO2 significantly (all P < 0.001). Moreover, it increased peak expiratory flow rate, oxygen saturation, temperature, heart rate and blood pressure (all P < 0.001). The two groups were similar in the bispectral index and mean arterial pressure (both P > 0.05). None of our participants had complications attributable to doxapram.

CONCLUSION

The postoperative use of doxapram improves peak expiratory flow rate, and decreases respiratory complications of anaesthesia during recovery in the morbidly obese undergoing bariatric surgery. Doxapram is well tolerated in young ASA physical status classes 1 to 2 morbidly obese patients; however, the anaesthesiologist should cautiously evaluate the vital signs for at least half an hour following the administration of doxapram.

REGISTRATION

Iranian Registry of Clinical Trials (IRCT) http://www.irct.ir/ number IRCT2017060712203N9.

Risk of Atrial Fibrillation and Stroke After Bariatric Surgery in Patients With Morbid Obesity With or Without Obstructive Sleep Apnea

[Figure: see text].

The influence of obstructive sleep apnea syndrome on anthropometric parameters at 12 months after laparoscopic sleeve gastrectomy

The aim of this study was to assess the influence of obstructive sleep apnea syndrome (OSAS) on the change in anthropometric parameters and body composition, in patients undergoing laparoscopic sleeve gastrectomy (LSG). This prospective study included patients undergoing LSG who had pre-operative polysomnography data and were also evaluated at six and 12 months after surgery. All patients included also had whole body composition analysis data before surgery and at six and 12 months after surgery. The results are presented in comparison between patients with and without OSAS. We included 73 patients in the analysis with a mean ± SD age and body mass index (BMI) of 40.3 ± 10.9 years and 45.4 ± 6.3 kg/m², respectively. As compared to the baseline levels, at 6 months there was a significant decrease in BMI, weight, waist circumference, serum glucose and HbA1c. At 12 months there was no further decrease as compared to the 6 months levels, irrespective of OSAS status. We observed a significant decrease at 6 months in percentage of fat, in both types of patients. However, as compared to the 6 months levels, at 12 months the percent fat had a significant decrease only in patients without OSAS (− 4.6%, 95% CI − 7.6 to − 1.7%) and not in those with OSAS (− 2.2%, 95% CI − 4.5 to 0.2%). In our study, patients with OSAS showed a similar decrease in different anthropometric parameters as those without OSAS after LSG. However, at 12 months of follow-up there was a significant decrease in the percent fat only in patients without OSAS.

Clinical and Research Solutions to Manage Obstructive Sleep Apnea: A Review

Obstructive sleep apnea (OSA), a common sleep disorder disease, affects millions of people. Without appropriate treatment, this disease can provoke several health-related risks including stroke and sudden death. A variety of treatments have been introduced to relieve OSA. The main present clinical treatments and undertaken research activities to improve the success rate of OSA were covered in this paper. Additionally, guidelines on choosing a suitable treatment based on scientific evidence and objective comparison were provided. This review paper specifically elaborated the clinically offered managements as well as the research activities to better treat OSA. We analyzed the methodology of each diagnostic and treatment method, the success rate, and the economic burden on the world. This review paper provided an evidence-based comparison of each treatment to guide patients and physicians, but there are some limitations that would affect the comparison result. Future research should consider the consistent follow-up period and a sufficient number of samples. With the development of implantable medical devices, hypoglossal nerve stimulation systems will be designed to be smart and miniature and one of the potential upcoming research topics. The transcutaneous electrical stimulation as a non-invasive potential treatment would be further investigated in a clinical setting. Meanwhile, no treatment can cure OSA due to the complicated etiology. To maximize the treatment success of OSA, a multidisciplinary and integrated management would be considered in the future.

Obstructive sleep apnea and early weight loss among adolescents undergoing bariatric surgery

BACKGROUND

Little is known regarding obstructive sleep apnea's (OSA's) prevalence or the factors related to OSA remission post-metabolic bariatric surgery (MBS) in adolescents.

OBJECTIVES

To identify the baseline OSA prevalence in adolescents with severe obesity and examine factors associated with post-MBS OSA remission.

SETTING

Tertiary-care children's hospital.

METHODS

We conducted a retrospective chart review of 81 patients pre-MBS with OSA assessments done between June 2017 to September 2020 to collect demographic characteristics; co-morbidities; polysomnography (PSG) results, if indicated; and weight data. Chi-square or Mann-Whitney tests compared baseline characteristics and surgical outcomes by pre-MBS OSA status. McNemar's test or t tests assessed differences in baseline characteristics, stratified by remission versus no remission of OSA.

RESULTS

The patients were 71% female, had an average age of 16.9 ± 2.0 years, and had a mean body mass index (BMI) of 47.9 ± 7.3 kg/m². Half (50%) of the patients were Hispanic and 20% had type 2 diabetes. The OSA prevalence, defined as an Obstructive Apnea Hypopnea Index (OAHI) score ≥5, was 54% pre-MBS (n = 44), with 43% having severe OSA (OAHI > 30). Those with OSA were older (17.3 versus 16.4 yr, respectively; P = .05), more likely to be male (79% versus 42%, respectively; P = .022), and had higher baseline weights (142.0 versus 126.4 kg, respectively; P = .001) than those without OSA. Of the 23 patients with a post-MBS PSG result (average 5 mo post MBS), 15 (66%) had remission of OSA. Patients with OSA remission had a lower average pre-MBS BMI (46.0 versus 57.7 kg/m², respectively; P < .001) and weight (132.9 versus 172.6 kg, respectively; P = .002) but no significant differences in percentage weight loss through 12 months post MBS versus those with continued OSA.

CONCLUSION

The OSA prevalence in an adolescent MBS population was higher than that in the general adolescent population with severe obesity. Remission of OSA was correlated with lower pre-MBS BMI and weight, but not weight loss within the first year post-MBS.

Bariatric surgery may provide better protection than uvulopalatopharyngoplasty against major adverse cardiovascular events in obese patients with obstructive sleep apnea

BACKGROUND

The major adverse cardiovascular events (MACE) risk is unclear among Asian obese patients with obstructive sleep apnea (OSA) who undergo bariatric surgery (BS) or uvulopalatopharyngoplasty (UPPP).

OBJECTIVES

We aimed to evaluate differences between Asian obese patients with OSA who underwent BS or UPPP regarding MACE.

SETTING

The Longitudinal Health Insurance Database, a subset of the NHI Research Database (NHIRD) originated from the National Health Insurance (NHI) program in Taiwan, which comprises information from 2 million randomly sampled individuals between 2000 and 2015.

METHODS

Participants aged 18-55 years whose diagnoses corresponded with codes in the International Classification of Diseases, Ninth Revision, Clinical Modification for BS, UPPP, obesity, and OSA were included in this population-based, matched cohort study of Taiwan's insurance claims data gathered between 2000 and 2015. Obese patients with OSA who underwent BS or UPPP were propensity score matched; the study's outcome was MACE.

RESULTS

A total of 1336 patients, comprising 668 in each of the BS and UPPP cohorts, were enrolled. After a mean follow-up period of 8.51 years, 166 patients, comprising 52 in the BS cohort and 114 in the UPPP cohort, experienced MACE. The adjusted hazard ratio (aHR) for MACE was .592 (95% confidence interval [CI] = .324-.789; P < .001). The BS cohort had lower risks of stroke (aHR = .663; 95% CI = .312-.890; P < .001), myocardial infarction (aHR = .116; 95% CI = .052-.135; P < .001), and mortality (aHR = .779; 95% CI = .423-.948; P = .001) than the UPPP cohort.

CONCLUSION

BS may provide greater protection against MACE than UPPP in Asian obese patients with OSA. Additional mechanistic research is needed to clarify differences between BS and UPPP in these patients.

A Review of the Current Evidence: Impact of Metabolic Surgery on Diabetes Outcomes and Obesity-Associated Macrovascular Complications

PURPOSE OF REVIEW

Type 2 diabetes (T2D) and obesity are comorbidities that generally progress with time even when non-invasive therapies are prescribed. Indeed, weight loss that is achieved with behavioral modification alone is generally inconsistent and often short-lived. In contrast, although patients do experience weight regain with metabolic surgery, they still benefit from a significant net decrease in weight. As a result, T2D remission can be achieved in up to 60% of patients within 2 years after surgery. However, it is unknown if the positive effects of metabolic surgery extend to macrovascular disease risk reduction.

RECENT FINDINGS

As noted in four randomized controlled trials (RCTs), Roux-en-Y gastric bypass (RYGB) facilitates partial remission of T2D in about 30% of volunteers 5 years after surgery. Of the four RCTs, only one investigated the effects of sleeve gastrectomy (SG) at 5 years; that study found that the rate of partial relapse was slightly lower with SG (23%). However, observational studies indicate that the gap between RYGB and SG may be larger than that observed in RCTs. In contrast, the rate of full remission is noted infrequently 5 years after SG or RYGB. Metabolic surgery also mitigates macrovascular disease risk as indicated by multiple observational studies. The effects of metabolic surgery on cardiometabolic parameters are clinically meaningful. The weight loss that is facilitated by metabolic surgery reduces the metabolic and inflammatory stress caused by T2D and obesity. In turn, metabolic surgery likely mitigates macrovascular disease risk. Additional evidence from RCTs is needed to substantiate the effects of metabolic surgery on macrovascular disease risk.

The association between obesity indices and obstructive sleep apnea is modified by age in a sex-specific manner

BACKGROUND

The beneficial effects of weight reduction on obstructive sleep apnea (OSA) are highly variable. Whether or not the variability is associated with the effects of age and sex remains unclear. This study examined this issue with large cross-sectional data.

METHOD

Anthropometric measurements, polysomnographic variables, biochemical indicators, and medical history were collected for each participant. Multivariable linear regression with interaction terms was used to estimate the modification effect of age on the associations between OSA severity (assessed by apnea-hypopnea index, AHI) with obesity indices (body mass index, BMI; neck circumference, NC; waist circumference, WC; waist-to-hip ratio, WHR) in a sex-specific manner, and vice versa. To facilitate interpretation of the results, participants were further classified into six subpopulations according to both sex and age, and population-specific beta-coefficients were calculated and compared.

RESULTS

A total of 5756 adults (4600 men) with suspected OSA were included in the study. BMI, NC, WC, and WHR were all positively correlated with AHI after adjusting for potential confounders in all populations. In men, these associations were much stronger and more significant in younger than older individuals (P for interaction < 0.001). For example, a 10% increase in BMI was independently associated with a 32% increase in AHI for men < 40 years old, whereas the corresponding increases were 21% and 17% for men 40-60 and > 60 years old, respectively. By contrast, no modification effect of age was observed in women (P for interaction > 0.05). A 10% increase in BMI was associated with 26%, 27%, and 24% increases in AHI for women < 40, 40-60, and > 60 years old, respectively.

CONCLUSIONS

Age modifies the associations between obesity indices and OSA severity in a sex-specific manner. These findings may broaden the understanding of age- and sex-related heterogeneities in the pathogenic role of obesity in OSA, and may be beneficial for individualized risk evaluation and treatment management for patients with OSA.

Clinical Practice Guidelines for the Perioperative Nutrition, Metabolic, and Nonsurgical Support of Patients Undergoing Bariatric Procedures - 2019 Update: Cosponsored by American Association of Clinical Endocrinologists/American College of Endocrinology, The Obesity Society, American Society for Metabolic and Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists

OBJECTIVE

The development of these updated clinical practice guidelines (CPGs) was commissioned by the American Association of Clinical Endocrinologists (AACE), The Obesity Society (TOS), American Society for Metabolic and Bariatric Surgery (ASMBS), Obesity Medicine Association (OMA), and American Society of Anesthesiologists (ASA) Boards of Directors in adherence with the AACE 2017 protocol for standardized production of CPGs, algorithms, and checklists.

METHODS

Each recommendation was evaluated and updated based on new evidence from 2013 to the present and subjective factors provided by experts.

RESULTS

New or updated topics in this CPG include: contextualization in an adiposity-based chronic disease complications-centric model, nuance-based and algorithm/checklist-assisted clinical decision-making about procedure selection, novel bariatric procedures, enhanced recovery after bariatric surgery protocols, and logistical concerns (including cost factors) in the current health care arena. There are 85 numbered recommendations that have updated supporting evidence, of which 61 are revised and 12 are new. Noting that there can be multiple recommendation statements within a single numbered recommendation, there are 31 (13%) Grade A, 42 (17%) Grade B, 72 (29%) Grade C, and 101 (41%) Grade D recommendations. There are 858 citations, of which 81 (9.4%) are evidence level (EL) 1 (highest), 562 (65.5%) are EL 2, 72 (8.4%) are EL 3, and 143 (16.7%) are EL 4 (lowest).

CONCLUSIONS

Bariatric procedures remain a safe and effective intervention for higher-risk patients with obesity. Clinical decision-making should be evidence based within the context of a chronic disease. A team approach to perioperative care is mandatory, with special attention to nutritional and metabolic issues.

Association between body mass index and effectiveness of continuous positive airway pressure in patients with obstructive sleep apnea: a retrospective study

PURPOSE

Ineffective use of continuous positive airway pressure (CPAP) therapy can result in inconvenience and additional costs in patients with obstructive sleep apnea (OSA). This study investigated the predictive value of body mass index (BMI) to assess the efficacy of CPAP in patients with OSA.

METHODS

Data were extracted from a retrospective study performed in Silkeborg Hospital. The primary outcome was the improvement of Apnea-Hypopnea Index (AHI) after CPAP treatment. Association between BMI and improvement of AHI was assessed by multivariable linear regression. Interactions between BMI, baseline AHI severity (≥ 30 or < 30), and diabetes were also evaluated.

RESULTS

Four hundred eighty-one patients were included in the study. After adjusting for confounders, high BMI (coefficient [coef], 0.80; 95% confidence interval [CI], 0.59-1.00; p < 0.001) and high AHI severity (AHI ≥ 30) (coef, 29.2; 95% CI, 26.7-31.7; p < 0.001) were associated with greater improvement of AHI after CPAP treatment, while diabetes was associated with less improvement of AHI (coef, - 4.91; 95% CI, - 9.40 to - 0.42; p = 0.032). Baseline AHI severity, diabetes, and BMI showed significant interactions (p < 0.001). On subgroup analysis, the association between BMI and improvement of AHI remained significant only in patients belonging to high AHI severity subgroup (coef, 1.18; 95% CI, 0.8-1.49; p < 0.001) and that without diabetes (coef, 1.42; 95% CI, 1.11-1.72; p < 0.001).

CONCLUSIONS

Patients with OSA having high BMI, without diabetes, are more likely to benefit from CPAP therapy. Future studies should explore the predictors of the efficacy of CPAP in more depth.

Sleep and Stroke: New Updates on Epidemiology, Pathophysiology, Assessment, and Treatment

PURPOSE OF REVIEW

This review aims to discuss the most recent data on sleep disorders and stroke, highlighting relevant findings for the practicing neurologist or health providers who encounter patients with sleep disorders and stroke.

RECENT FINDINGS

Sleep apnea and abnormal sleep duration have the strongest association with stroke risk. Possible mechanisms include non-dipping of blood pressure during sleep, hypoxemia or reoxygenation leading to sympathetic activation, hypertension, atrial fibrillation and impaired cerebral hemodynamics. Treatment studies suggest that continuous positive airway pressure (CPAP) for sleep apnea could improve primary prevention of stroke, but data is equivocal for secondary prevention. However, CPAP could improve functional outcomes after stroke.

SUMMARY

Sleep disorders present an opportunity to improve stroke risk and functional outcomes. However, new strategies are needed to determine the patients at high-risk who would most likely benefit from targeted care. Novel methods for phenotyping sleep disorders could provide personalized stroke care to improve clinical outcomes and public health strategies.