Screening for Obstructive Sleep Apnea in a Diverse Bariatric Surgery Population

Potential Therapeutic Targets in Obesity, Sleep Apnea, Diabetes, and Fatty Liver Disease

Obesity and metabolic syndrome affect the majority of the US population. Patients with obesity are at increased risk of developing type 2 diabetes (T2DM), obstructive sleep apnea (OSA), and metabolic dysfunction-associated steatotic liver disease (MASLD), each of which carry the risk of further complications if left untreated and lead to adverse outcomes. The rising prevalence of obesity and its comorbidities has led to increased mortality, decreased quality of life, and rising healthcare expenditures. This phenomenon has resulted in the intensive investigation of exciting therapies for obesity over the past decade, including more treatments that are still in the pipeline. In our present report, we aim to solidify the relationships among obesity, T2DM, OSA, and MASLD through a comprehensive review of current research. We also provide an overview of the surgical and pharmacologic treatment classes that target these relationships, namely bariatric surgery, the glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon receptor agonists.

Assessment of obesity

Obesity is a chronic, progressive and relapsing disease, characterised by the presence of abnormal or excess adiposity that impairs health and social wellbeing. It is associated with obesity-related disease complications, health inequalities and premature death. Clinical evaluation of obesity requires a thorough history and examination. Assessment should focus not only on anthropometric measurements, but also on the mental, metabolic, mechanical and monetary impact of adiposity, including multiple health conditions. Increased awareness and knowledge will help reduce weight stigma and biases. A focused non-judgemental assessment will help guide further investigations, timely referral and management.

Sleep Apnea, Obesity, and Diabetes - an Intertwined Trio

PURPOSE OF REVIEW

To synthesize the existing literature regarding the complex interplay between sleep disturbance, obesity, and diabetes. The review emphasizes the three pillars of health being diet, exercise, and sleep, with the notion that if one is ignored, then the other two could suffer.

RECENT FINDINGS

Sleep deprivation is associated with incident obesity, perhaps mediated by dysregulation in leptin and ghrelin - hormones important in regulation of appetite. Sleep apnea is very common particularly among obese people with type 2 diabetes mellitus. Treatment of sleep apnea has clear symptomatic benefits although its impact on long-term cardiometabolic health is less clear. Sleep disturbance may be an important modifiable risk for patients at risk of cardiometabolic disease. An assessment of sleep health may be an important component of the comprehensive care of patients with obesity and diabetes mellitus.

Effect of high-risk factors on postoperative major adverse cardiovascular and cerebrovascular events trends following bariatric surgery in the United States from 2012 to 2019

BACKGROUND

Recent examination of trends in postoperative major adverse cardiovascular and cerebrovascular events (MACE) following bariatric surgery, including accredited and nonaccredited centers, and the factors affecting those trends, is lacking.

OBJECTIVES

The objective of this study was to evaluate current trends for postoperative MACE after bariatric surgery in both accredited and nonaccredited centers and the factors affecting these trends.

SETTING

This retrospective study was conducted using National Inpatient Sample database from 2012 to 2019.

METHODS

All patients who underwent inpatient laparoscopic sleeve gastrectomy (LSG), open sleeve gastrectomy (SG), laparoscopic Roux-en-Y gastric bypass (LRYGB), and open Roux-en-Y gastric bypass (RYGB) were examined. Composite MACE (acute myocardial infarction, cardiac arrest, acute stroke, and in-hospital death during bariatric surgery hospitalization) was calculated and analyzed over time along with patient demographic and co-morbid diseases using survey-weighted logistic regression.

RESULTS

MACE incidence was lowest for LSG (0.07%), followed by LRYGB (0.16%), SG (3.47%), and RYBG (3.51%). Open procedure, increasing age, male sex, body mass index ≥50, coronary artery disease, congestive heart failure, and chronic kidney disease were independent predictors for increased MACE risk. MACE incidence increased over time for SG (odds ratio [OR] 1.25 [1.16, 1.34]; P < .0001) and RYGB (OR 1.14 [1.06, 1.22]; P = .0004) but decreased for LRYGB (OR 0.93 [0.87, 1] P = .06). After adjustment for high-risk covariates, increased MACE trend seen over time was attenuated in SG (OR 1.13 [1.04-1.22]; P = .005) and RYGB (OR 1.04 [0.96-1.12]; P = .36), while there was minimal effect of these high-risk covariates on MACE trend over time in LSG and LRYGB.

CONCLUSIONS

MACE following LSG and LRYGB is rare, occurring in 0.1% of patients. Persistently increasing high-risk conditions and demographics has had minimal effect on MACE over time for LSG and LRYGB but has had significant effect on MACE trend over time in SG and RYGB.

Validation of the STOP-Bang questionnaire as a preoperative screening tool for obstructive sleep apnea: a systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA) is a common disorder that is highly associated with postoperative complications. The STOP-Bang questionnaire is a simple screening tool for OSA. The objective of this systematic review and meta-analysis is to evaluate the validity of the STOP-Bang questionnaire for screening OSA in the surgical population cohort.

METHODS

A systematic search of the following databases was performed from 2008 to May 2021: MEDLINE, Medline-in-process, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, PsycINFO, Journals @ Ovid, Web of Science, Scopus, and CINAHL. Continued literature surveillance was performed through October 2021.

RESULTS

The systematic search identified 4641 articles, from which 10 studies with 3247 surgical participants were included in the final analysis. The mean age was 57.3 ± 15.2 years, and the mean BMI was 32.5 ± 10.1 kg/m² with 47.4% male. The prevalence of all, moderate-to-severe, and severe OSA were 65.2, 37.7, and 17.0%, respectively. The pooled sensitivity of the STOP-Bang questionnaire for all, moderate-to-severe, and severe OSA was 85, 88, and 90%, and the pooled specificities were 47, 29, and 27%, respectively. The area under the curve for all, moderate-to-severe, and severe OSA was 0.84, 0.67, and 0.63.

CONCLUSIONS

In the preoperative setting, the STOP-Bang questionnaire is a valid screening tool to detect OSA in patients undergoing surgery, with a high sensitivity and a high discriminative power to reasonably exclude severe OSA with a negative predictive value of 93.2%.

TRIAL REGISTRATION

PROSPERO registration  CRD42021260451 .

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.

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

Diagnostic performance of screening tools for the detection of obstructive sleep apnea in people living with HIV

STUDY OBJECTIVES

Many people living with HIV (PLWH) have undiagnosed obstructive sleep apnea (OSA), which may contribute to commonly reported fatigue and the high cardiovascular disease burden in this population. Our objective was to assess the utility of traditional OSA screening tools (STOP-BANG, Berlin Questionnaire (BQ), and Epworth Sleepiness Scale (ESS)) for detecting OSA in PLWH.

METHODS

Adult PLWH were recruited from sleep/HIV clinics and the community into a larger clinical trial which included completion of these questionnaires before in-laboratory polysomnography. Discriminatory performance of these screening tools was assessed using area under receiver operating characteristic curves (AUC). The reference standard for the primary analysis was OSA based on an AHI≥5/h using recommended "1A"-criteria (hypopnea with 3%-desaturation and/or arousal). Secondary analyses explored acceptable "1B"-criteria (hypopnea with 4%-desaturation) and/or higher AHI cut-offs (≥15/h).

RESULTS

120 PLWH were included (mean-age: 50±11 years; body mass index: 27±4 kg/m², 84% male) and OSA was diagnosed in 75% using 1A-criteria. In the primary analysis, the discriminatory performance of the three screening tools was low (AUCs 0.58 to 0.70) and similar across the tools (P≥0.14). In secondary analyses, STOP-BANG showed moderate-high discriminatory ability (AUCs 0.77-0.80) and performed significantly better (P≤0.008) than the BQ or ESS (AUCs 0.53-0.62).

CONCLUSIONS

OSA was highly prevalent in our cohort of PLWH. Although STOP-BANG could reasonably identify moderate-severe OSA, the tools were not reliable for mild disease. Specifically, the questionnaires perform poorly for PLWH with mild OSA manifesting with arousals, yet such people may be at risk of fatigue/sleepiness and impaired memory consolidation.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Obstructive Sleep Apnea Endotypes and Impact on Phenotypes of People Living With HIV (PLWH/OSA); Identifier: NCT03575143; URL: https://clinicaltrials.gov/ct2/show/NCT03575143.

Weight reduction added to CPAP decreases blood pressure and triglyceride level in OSA: systematic review and meta-analysis

Obstructive sleep apnea (OSA) is associated with treatment‐resistant hypertension and high cardiovascular risk. Continuous positive airway pressure (CPAP) fails to reduce cardiovascular risks consistently. Obesity and OSA show reciprocal association and they synergistically increase hypertension via different pathways. Our meta‐analysis aimed to assess the cardiovascular benefits of combining weight loss (WL) with CPAP (vs. WL or CPAP alone) in OSA. Outcomes included systolic and diastolic blood pressure (BP) and blood lipid parameters. We explored Medline, Embase, Cochrane, and Scopus. Eight randomized controlled studies (2627 patients) were included. The combined therapy decreased systolic BP more than CPAP alone. Weighted mean difference (WMD) for CPAP + WL versus CPAP was −8.89 mmHg, 95% confidence interval (95% CI; −13.67 to −4.10, p < 0.001) for systolic BP. For diastolic BP, this decrease was not significant. In case of blood lipids, the combined treatment decreased triglyceride levels more than CPAP alone (WMD = −0.31, 95% CI −0.58 to −0.04, p = 0.027). On the other hand, addition of CPAP to WL failed to suppress BP further. The certainty of evidence according to GRADE was very low to moderate. In conclusion, our results showed that the addition of WL to CPAP significantly improved BP and blood lipid values in OSA. On the other hand, the addition of CPAP to WL could not significantly improve BP or blood lipid values. Review protocol: PROSPERO CRD42019138998.

Clinical outcomes of bariatric surgery - Updated evidence

Obesity has grown to become a major health problem over the past few decades. Obesity-related comorbidities, such as diabetes mellitus, hypertension, obstructive sleep apnea, and dyslipidemia, are inextricably linked with increased adverse clinical consequences and mortality. Compared with other strategies for obesity, bariatric surgery is efficient in weight loss and has been proved to exert positive effects on obesity-related risk factors. This broad improvement in risk factors has resulted in substantial remission or reductions of comorbidities and better performance on clinical outcomes, including cardiovascular diseases, cancer, and mortality. With the development of surgical procedures, the safety of bariatric surgery has been validated and the rate of peri-operative death is low all over the world. Nonetheless, surgeons ought to be careful about potential complications, such as nutrition deficiencies, psychological disorders, or new digestive tract tumors after surgery. For patients with obesity, bariatric surgery might be a precious and crucial tool to bring additional benefits including comorbidities protection and life span extension. All patients with obesity should be engaged in a union consultation group to select a suitable treatment.

Predictive Factors for Obstructive Sleep Apnea Diagnosis in Bariatric Surgery Candidates with or Without Chronic Insomnia Complaints

OBJECTIVE

This study aims to evaluate the frequency of insomnia complaints in bariatric patients and to assess obstructive sleep apnea (OSA) predictors according to the presence or absence of chronic insomnia.

METHODS

Insomnia was defined as the presence of at least one specific symptom: difficulty falling asleep, difficulty maintaining sleep, and/or waking up earlier than expected. Diagnosis of OSA was objectively obtained from in-laboratory polysomnography. Multivariate logistic regression analysis was used to assess OSA predictors.

RESULTS

This cross-sectional study contains 1,737 bariatric surgery candidates: 59.6% without insomnia and 40.4% with insomnia. OSA prevalence was similar among participants with or without insomnia either for any OSA (p = 0.168) or for moderate-to-severe OSA (p = 0.185). Patients without insomnia showed a higher prevalence of severe OSA than those with insomnia (p = 0.005). In both cohorts, five parameters were independent OSA predictors: sex, age, body mass index (BMI), neck circumference (NC), and excessive daytime sleepiness (EDS). Male sex was the most important predictor, whether in individuals without insomnia (adjusted odds ratio [OR] ranging from 4.874 to 8.369) or in those with insomnia (adjusted OR ranging from 5.672 to 12.441).

CONCLUSIONS

A considerable proportion of bariatric patients report insomnia complaints. The probability of suffering from OSA was similar among bariatric candidates with or without insomnia, except for severe OSA diagnosis. Sex, age, BMI, NC, and EDS were independent predictors for OSA diagnosis irrespective of insomnia symptoms, and male sex was the main predictor for OSA in bariatric individuals with or without insomnia.

Are there sex-related differences in therapeutic CPAP levels in adults undergoing in-lab titration?

STUDY OBJECTIVES

The first-choice therapy for adults with moderate/severe obstructive sleep apnea (OSA) is continuous positive airway pressure (CPAP). However, studies evaluating whether the therapeutic CPAP level obtained from a titration is affected by sex are surprisingly scarce. Our main objective was to verify if sex influenced the optimal CPAP measurement obtained during a titration.

METHODS

This cross-sectional study was conducted in adults diagnosed with moderate/severe OSA (baseline apnea-hypopnea index [AHI] ≥ 15.0/h), who underwent auto-adjusting CPAP titration (S9 or S10 AutoSet ResMed) in a sleep-lab setting. All participants used a nasal mask during the titration. The optimal pressure, leak, and residual AHI values were registered. Multiple linear regression was used to evaluate if clinical and polysomnographic data influenced the therapeutic CPAP level setting (95^th percentile pressure).

RESULTS

A total of 1,006 adults were enrolled: 354 women and 652 men. There were no statistically significant sex-related differences in the CPAP requirements and leak values as delineated during the titration; all p-values > 0.005. However, the median residual AHI was significantly higher in males versus females: 2.7/h versus 2.2/h (p = 0.008). Body mass index [BMI] (β: 0.292, p < 0.001), baseline AHI (β: 0.167, p < 0.001), and age (β: 0.065, p = 0.035) were independent predictors of the therapeutic CPAP level settings.

CONCLUSIONS

Sex does not significantly influence the therapeutic CPAP settings. However, age, BMI, and baseline AHI emerge as independent predictors of the 95^th percentile CPAP requirement during an auto-adjusting CPAP titration.

Development and Validation of a Nomogram for Predicting Obstructive Sleep Apnea in Bariatric Surgery Candidates

BACKGROUND

Obstructive sleep apnea (OSA) is highly prevalent in bariatric surgery patients and can lead to potential perioperative risks, but some screening tools lack adequate performance in this population. Thus, we aimed to develop and validate a clinical nomogram for predicting OSA in bariatric surgery candidates.

METHODS

We retrospectively collected the data of 482 bariatric surgery patients between September 2015 and January 2020. Patients were randomly classified into training cohort (n=338) and validation cohort (n=144). The Lasso regression was used to select potentially relevant features; then, multivariable logistic regression analysis was used to establish the nomogram. Discrimination, calibration and clinical usefulness of the nomogram were assessed using the C-index, calibration curve and decision curve analysis (DCA).

RESULTS

The overall prevalence of OSA was 71.0% and higher in males (88.2%) compared to females (60.1%). Of these, 26.1% had mild OSA, 14.9% had moderate OSA, and 44.8% had severe OSA. The nomogram consisted of gender, habitual snoring, type 2 diabetes mellitus (T2DM), neck circumference, body mass index (BMI) and age. The nomogram provided favorable discrimination, with a C-indexes for the training and validation cohort of 0.856 (95% CI: 0.816-0.897) and 0.829 (95% CI: 0.76-0.895), respectively, and good calibration. The DCA displayed that the nomogram was clinically useful.

CONCLUSION

We established a concise and practical nomogram that could facilitate the preoperative individualized prediction of OSA before bariatric surgery, which may help clinicians select bariatric surgery patients with high-risk OSA for polysomnography (PSG).