Increased exercise capacity after surgically induced weight loss in morbid obesity

Effect of bariatric surgery on cardio-psycho-metabolic outcomes in severe obesity: A randomized controlled trial

OBJECTIVE

Randomized evidence comparing the cardiovascular effects of surgical and conservative weight management is lacking.

PATIENTS & METHODS

In this single-center, open-label randomized trial, obese patients with indication for Roux-en-Y gastric bypass (RYGB) and able to perform treadmill cardiopulmonary exercise testing (CPET) were included. After a 6-12 month run-in phase of multimodal anti-obesity treatment, patients were randomized to RYGB or psychotherapy-enhanced lifestyle intervention (PELI) and co-primary endpoints were assessed 12 months later. Thereafter, PELI patients could opt for surgery and patients were reassessed 24 months after randomization. Co-primary endpoints were mean change (95 % confidence intervals) in peak VO2 (ml/min/kg body weight) in CPET and the physical functioning scale (PFS) of the Short Form health survey (SF-36).

RESULTS

Of 93 patients entering the study, 60 were randomized. Among these (median age 38 years; 88 % women; mean BMI 48·2 kg/m2), 46 (RYGB: 22 and PELI: 24) were evaluated after 12 months. Total weight loss was 34·3 % after RYGB vs. 1·2 % with PELI, while peak VO2 increased by +4·3 ml/min/kg (2·7, 5·9) vs +1·1 ml/min/kg (-0·2, 2·3); p < 0·0001. Respective improvement in PFS score was +40 (30, 49) vs +10 (1, 15); p < 0·0001. 6-minute walking distance also favored the RYGB group: +44 m (17, 72) vs +6 m (-14, 26); p < 0·0001. Left ventricular mass decreased after RYGB, but not with PELI: -32 g (-46, -17) vs 0 g (-13,13); p < 0·0001. In the non-randomized follow-up, 34 patients were assessed. Favorable changes were sustained in the RYGB group and were repeated in the 15 evaluated patients that opted for surgery after PELI.

CONCLUSIONS

Among adults with severe obesity, RYGB in comparison to PELI resulted in improved cardiopulmonary capacity and quality of life. The observed effect sizes suggest that these changes are clinically relevant.

Analysis of Walking Economy after Sleeve Gastrectomy in Patients with Severe Obesity

BACKGROUND

Obesity is associated with a higher energy cost of walking which affects activities of daily living. Bariatric surgery with sleeve gastrectomy (SG) has beneficial effects on weight loss and comorbidities.

PURPOSE

The aim of this study was to analyze the impact of SG on walking economy in subjects with severe obesity.

METHODS

This observational cohort study included all patients with morbid obesity who were considered suitable candidates for SG between June 2017 and June 2019. Each patient underwent an incremental cardiopulmonary exercise test on a treadmill (modified Bruce protocol) one month before and six months after SG. Data on the energy cost of walking were recorded during three protocol stages (stage 0-slow flat walking: speed 2.7 km/h, slope 0%; stage ½-slow uphill walking: speed 2.7 km/h, slope 5%; stage 1-fast uphill walking: speed 4.0 km/h, slope 8%).

RESULTS

139 patients with morbid obesity (78% women; age 44.1 ± 10.7 years; BMI 42.5 ± 4.7 kg/m²) were included in the study. At six months post-SG, patients presented with a significantly decreased body weight (-30.5 ± 17.2 kg; p < 0.05), leading to an average BMI of 31.6 ± 4.2 kg/m². The net energy cost of walking (measured in J/m and J/kg/m) of the subjects was lower compared to pre-SG at all three protocol stages. This improvement was also confirmed when the subjects were grouped by gender and obesity classes.

CONCLUSION

After a significant weight loss induced by SG, regardless of the severity of obesity and gender, patients exhibited a lower energy expenditure and an improved walking economy. These changes make it easier to perform daily routines and may facilitate an increase in physical activity.

Aerobic exercise capacity is normal in obesity with or without metabolic syndrome

BACKGROUND

Obesity might be a cause of limited aerobic exercise capacity. It is often associated with metabolic syndrome (MS) that includes cardiovascular comorbidities as arterial hypertension. Cardiopulmonary exercise testing (CPET) is the gold-standard to assess aerobic capacity and discriminate causes of dyspnea.

AIM

To evaluate aerobic capacity in obesity and if MS or hypertensive treatment impacts on the CPET profile.

METHODS

CPET of 146 obese patients, whom 33 and 31 were matched for MS and antihypertensive medication, were analyzed. VO_2peak (mL/min/Kg) was reported in percentage of predicted value, or, divided by body weight, fat free mass (FFM) or body weight expected for a body mass index of 24 (BMI24).

RESULTS

VO_2peak (20,8 ± 4,4 mL/min/Kg) was normal when expressed in percentage predicted for obesity (111 ± 22%pred) or divided by FFM and weight_BMI24 (33,6 ± 5,6 and 30,6 ± 6,2 respectively). The latter correlated better with maximal work rate (r = 0,7168, p < 0,001). Obese patients showed normal ventilatory efficiency (ventilation to carbon dioxide production slope: 28 ± 4), VO₂ to work rate (10,2 ± 1,6 mLO₂/Watt) and, slightly elevated heart rate to VO₂ slope (4,0 ± 1,1 bpm/mL/min/Kg). Compared to normotensives, hypertensive medicated patients had higher blood pressure at anaerobic threshold (142 ± 23 vs 158 ± 26 mmHg, p = 0,001) but not at maximal exercise (189 ± 31 vs 201 ± 23 mmHg, p = NS), and, had lower actual maximal heart rate (155 ± 23 vs 143 ± 25 bpm, p = 0,03). There was no difference between obese patients with or without MS.

CONCLUSION

Obese people with or without MS present with similar and normal aerobic profile related to the excessive body weight. VO_2peak divided by weight_BMI24 is an easy and clinical meaningful index for obese patients.

Short-Term Effect of Bariatric Surgery on Cardiorespiratory Response at Submaximal, Ventilatory Threshold, and Maximal Exercise in Women with Severe Obesity

PURPOSE

People with obesity have varying degrees of cardiovascular, pulmonary, and musculoskeletal dysfunction that affect aerobic exercise testing variables. Short time after bariatric surgery, these dysfunctions could affect both peak oxygen consumption ([Formula: see text] O₂ peak), the gold standard for assessing cardiorespiratory fitness (CRF) and aerobic capacity evaluated with ventilatory threshold (VT1). The purpose of this study was to evaluate the short-term effect of bariatric surgery, i.e. before the resumption of physical activity, on submaximal, at VT1 and maximal cardiorespiratory responses in middle-aged women with severe obesity.

MATERIALS AND METHODS

Thirteen middle-aged women with severe obesity (age: 36.7 ± 2.3 years; weight: 110.5 ± 3.6 kg, BMI: 41.8 ± 1.1 kg/m²) awaiting bariatric surgery participated in the study. Four weeks before and 6 to 8 weeks after surgery, body composition was determined by bioelectrical impedance. The participants performed an incremental cycling test to [Formula: see text] O₂ peak.

RESULTS

After bariatric surgery, all body composition parameters were reduced, absolute [Formula: see text] O₂ peak and peak workload decline with a lower VT1. Relative [Formula: see text] O₂ at peak and at VT1 (ml/min/kg or ml/min/kg of FFM) remained unchanged. Ventilation was lower after bariatric surgery during exercise with no change in cardiac response.

CONCLUSION

Our results showed that weight loss alone at short-term after bariatric surgery decreased CRF as seen by a decrease in absolute [Formula: see text] O₂ peak, and peak workload with lower VT1, whereas relative [Formula: see text] O₂ (ml/min/kg or ml/min/kg of FFM) during exercise remained unchanged in women with obesity. Rapid FFM loss affects cardiorespiratory responses at submaximal and maximal.

The incidence of cardiac arrhythmias during exercise stress testing: a focus on patients with severe obesity undergoing sleeve gastrectomy

INTRODUCTION

Obesity is associated with a higher risk of cardiac arrhythmias. Sleeve gastrectomy (SG) is a common bariatric surgery with beneficial effects on weight loss and comorbidities. The study aimed to investigate the prevalence of arrhythmias during maximal exercise testing in patients with moderate-severe obesity and to evaluate the impact of SG on these arrhythmic events.

METHODS

All patients with moderate or severe obesity who were considered suitable candidates for SG between June 2015 and September 2020 were recruited. Each patient underwent three incremental, maximal, ECG-monitored cardiopulmonary exercise test 1 month before and 6 and 12 months after SG; the frequency and complexity of ventricular premature beats (VPBs) and atrial premature beats (APBs) have been evaluated during rest, exercise and recovery phases.

RESULTS

Fifty patients with severe obesity (BMI 46.39 ± 7.89 kg/m²) were included in the study. After SG, patients presented a decreased BMI (34.15 ± 6.25 kg/m² at 6 months post-SG and 31.87 ± 5.99 kg/m² at 12 months post-SG). At 6 months post-SG, an increase in VPBs, mainly during the recovery phase, was observed. At 12 months post-SG, a reduction in VPBs compared with the 6 months evaluation was showed.

CONCLUSION

Although in the early post-surgical phase the risk of exercise-induced arrhythmias may be higher, SG does not seem to increase the occurrence of arrhythmias in the long-term. No life-threating arrhythmias were found during post-SG evaluations.

Translation and Validation of the Arabic Version of the Eating Behavior After Bariatric Surgery (EBBS) Questionnaire

PURPOSE

Complications after metabolic and bariatric surgery are common due to the patient's poor commitment to postoperative lifestyle changes. Therefore, intensive follow-up from a multidisciplinary team might improve outcomes. The present study aimed to translate and validate the Eating Behavior after Bariatric Surgery (EBBS) questionnaire into Arabic for use in clinical and research settings.

MATERIALS AND METHODS

The study followed World Health Organization guidelines for translation and questionnaire adaptation, including forward translation, back translation, pilot testing, and the creation of the final version of the tool. A total of 390 patients who had undergone metabolic and bariatric surgery 3 years ago or more were involved in testing the questionnaire's validity and reliability.

RESULTS

The mean age of participants was 36 years (range: 20 to 70 years), 56% were females, 94.1% were Saudis, and 56% had bachelor's degrees. The internal consistency of the questionnaire was tested using Cronbach's alpha. One item (alcohol consumption) was excluded during the reliability analysis due to low variance. The reliability analysis results showed that the 10 items were internally consistent, with a Cronbach's α of 0.851.

CONCLUSION

The validation and reliability of the Arabic-language version of the EBBS questionnaire were found to be satisfactory. The presence of a validated Arabic version of this instrument may help practitioners estimate patients' adherence to dietary and lifestyle recommendations after metabolic and bariatric surgery. Furthermore, the questionnaire may aid in identifying factors that influence the efficacy of these procedures.

30-Day Postoperative Outcomes in Patients With Limited Mobility - A Propensity Score-Matched Comparative Analysis

INTRODUCTION

There is limited data correlating preoperative mobility limitations with clinical outcomes in bariatric patients. This study uses propensity score matching (PSM) to compare 30-day outcomes between patients with preoperative limited mobility (LM) versus patients without (non-LM).

METHODS

Using the 2016-2018 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database, patients undergoing primary laparoscopic sleeve gastrectomy or gastric bypass were identified. Two cohorts were defined using preoperative LM status. To adjust for confounders, 1:1 PSM was performed using 25 preoperative characteristics, and balance was assessed with standardized mean difference. Preoperative patient demographics and postoperative 30-day outcomes were compared in both matched and unmatched cohorts.

RESULTS

453,146 patients were identified, of which 6942 (1.47%) were LM and 464,555 were non-LM. 1:1 PSM matched 6624 LM to 6624 non-LM patients with good balance for all covariates. LM had higher rates of unplanned intubation (0.4% vs 0.7%, P < .01), unplanned admission to ICU (1.4% vs 2.5%, P < .01), readmissions (4.1% vs 4.9%, P = .036), unplanned reoperation (1.5% vs 2.0%, P = .02), and 30-day mortality (0.2% vs 0.5%, P = .02). Complications including acute renal failure, intra/postoperative myocardial infarction, venous thrombosis, and pulmonary embolism were not significantly different between the matched groups.

CONCLUSION

After adjusting for confounders, patients with preoperative limited mobility have higher rates of intubation, ICU admission, reoperation, readmission, and mortality. Prudent pre-operative candidate selection, counseling, and risk mitigation strategies are needed when a patient with limited mobility status is being considered for bariatric surgery.

Effects of bariatric surgery on cardiorespiratory fitness: A systematic review and meta-analysis

Although bariatric surgery (BS) is recognized as an effective strategy for body weight loss, its impact on cardiorespiratory fitness (CRF) is still unclear. We aimed to examine postoperative changes in CRF (VO_2max/peak ) and its relationship with weight loss among adults undergoing BS. We systematically searched the WoS, PubMed, MEDLINE, and Scopus databases. Observational and intervention studies were selected reporting the presurgery and postsurgery CRF, measured by breath-by-breath VO₂ or its estimation. Eleven articles (312 patients) revealed that BS leads to a reduction in absolute VO_2max/peak in the short term (effect size, ES = -0.539; 95%CI = -0.708, -0.369; p < 0.001), and those patients who suffered a more significant decrease in BMI after BS also had a greater loss of absolute VO_2max/peak . However, VO_2max/peak relative to body weight increased after surgery (ES = 0.658; 95%CI = 0.473, 0.842; p < 0.001). An insufficient number of studies were found investigating medium and long-term changes in CRF after BS. This study provides moderate-quality evidence that the weight loss induced by BS can reduce CRF in the short term, which represents a therapeutic target to optimize BS outcomes. More high-quality studies are needed to evaluate the impact of BS on VO_2max/peak in the short, medium, and long term including normalized values for fat-free mass.

Cardio-psycho-metabolic outcomes of bariatric surgery: design and baseline of the WAS trial

Obesity is a rapidly emerging health problem and an established risk factor for cardiovascular diseases. Bariatric surgery profoundly reduces body weight and mitigates sequelae of obesity. The open, randomized controlled Würzburg Adipositas Studie (WAS) trial compares the effects of Roux-en-Y gastric bypass (RYGB) vs psychotherapy-supported lifestyle modification in morbidly obese patients. The co-primary endpoint addresses 1-year changes in cardiovascular function (peak VO2 during cardiopulmonary exercise testing) and the quality of life (QoL) (Short-Form-36 physical functioning scale). Prior to randomization, all included patients underwent a multimodal anti-obesity treatment for 6-12 months. Thereafter, the patients were randomized and followed through month 12 to collect the primary endpoints. Afterwards, patients in the lifestyle group could opt for surgery, and final visit was scheduled for all patients 24 months after randomization. Sample size calculation suggested to enroll 90 patients in order to arrive at minimally 22 patients per group evaluable for the primary endpoint. Secondary objectives were to quantify changes in body weight, left ventricular hypertrophy, systolic and diastolic function (by echocardiography and cardiac MRI), functional brain MRI, psychometric scales, and endothelial and metabolic function. WAS enrolled 93 patients (72 women, median age 38 years, BMI 47.5 kg/m2) exhibiting a relevantly compromised exercise capacity (median peakVO2 18.3 mL/min/kg) and the QoL (median physical functioning scale 50). WAS is the first randomized controlled trial focusing on the effects of RYGB on cardiovascular function beyond hypertension. In addition, it will provide a wealth of high-quality data on the cerebral, psychiatric, hepatic, and metabolic function in obese patients after RYGB.

Assessment of Cardiorespiratory and Metabolic Responses in Women with Obesity After Surgically Induced Weight Loss: Results from a Pilot Study

PURPOSE

Bariatric surgery is effective in controlling severe obesity. However, studies investigating the impact of surgically induced weight loss on cardiorespiratory and metabolic responses during maximal effort are controversial. The aim of this study was to assess cardiorespiratory and metabolic responses in women with obesity after bariatric surgery.

MATERIALS AND METHODS

We performed a secondary analysis on data from a pilot study with women with obesity submitted to bariatric surgery and who did not participate in a controlled physical training program. Anthropometry, pulmonary function (spirometry), and cardiorespiratory fitness (cardiopulmonary exercise testing [CPX]) were assessed before and after bariatric surgery.

RESULTS

Thirty-four women were included (38.7 ± 9.6 years, body mass index = 44.1 ± 6.3 kg/m²). Postoperative assessment was conducted 9.4 ± 2.7 months after surgery. After surgery, we observed a reduction in all anthropometric measurements (mean loss of 28.6 kg, p < 0.001), and improvement in spirometry values (p < 0.001). Relative VO_2peak (mL/kg/min) increased slightly (Δ = 1.7; p = 0.06); however, absolute VO_2peak (L/min) reduced significantly (Δ =  - 0.398; p < 0.001). We also observed an increase of 1.3 min (p < 0.001) in CPX duration, a reduction of 11.3 bpm (p < 0.001) in resting heart rate, and a decrease of systolic (p = 0.02) and diastolic (p < 0.001) blood pressures at peak effort.

CONCLUSION

Surgically induced weight loss without exercise training improved cardiac reserve, ventilatory response, blood pressure, and resting heart rate. Cardiorespiratory fitness reflected by relative VO_2peak increased slightly, despite increased tolerance to CPX.

How Does Fat Mass Change in the First Year After Bariatric Surgery? A Systemic Review and Meta-Analysis

This systematic review and meta-analysis investigated the time-course effect of different type of bariatric surgeries (BS) up to 1 year post-surgery on fat mass (FM) and body fat percentage (BFP) in patients with morbid obesity. We searched PubMed, Scopus, EMBASE, ISI web of science, and Cochrane databases from October 2002 until May 2020 with no restriction in the English language, to find studies examining the effect of BS on FM (kg) and BFP (%) in morbid obese patients. Meta-analysis of 103 studies carried out on data of 18,166 and 14,575 morbid obese patients following BS, showed that BS was associated with a substantial decrease in FM and BFP, respectively, in 1 month (- 8.17 kg [95% CI - 9.07, - 7.27] and - 1.51% [95% CI - 2.56, - 0.46]), 3 months (- 15.75 [95% CI - 17.49, - 14.0] and - 4.90 [95% CI - 5.97, - 3.83]), 6 months (- 22.51 [95% CI - 23.93, - 21.09] and - 8.56% [95% CI - 9.63, - 7.49]), and 12 months (- 29.69 [95% CI - 31.3, - 28.09] and - 13.49% [95% CI - 14.52, - 12.40]) after the surgery. In conclusion, BS was associated with sustained declines in FM and BFP, from 1 to 12 months, with no indication of plateau phase post-surgery post-operatively. The present study emphasizes that post-bariatric care should have more focus on FM loss during 1-year post-surgery to identify the patients at risk for fat loss plateau.

IGFBP-2 partly mediates the early metabolic improvements caused by bariatric surgery

Insulin-like growth factor-binding protein (IGFBP)-2 is a circulating biomarker of cardiometabolic health. Here, we report that circulating IGFBP-2 concentrations robustly increase after different bariatric procedures in humans, reaching higher levels after biliopancreatic diversion with duodenal switch (BPD-DS) than after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). This increase is closely associated with insulin sensitization. In mice and rats, BPD-DS and RYGB operations also increase circulating IGFBP-2 levels, which are not affected by SG or caloric restriction. In mice, Igfbp2 deficiency significantly impairs surgery-induced loss in adiposity and early improvement in insulin sensitivity but does not affect long-term enhancement in glucose homeostasis. This study demonstrates that the modulation of circulating IGFBP-2 may play a role in the early improvement of insulin sensitivity and loss of adiposity brought about by bariatric surgery.

Bariatric Surgery in Adults with Obesity: the Impact on Performance, Metabolism, and Health Indices

This systematic review summarizes current evidence on the impact of bariatric surgery (BS) on physical performance, metabolic, and health indices in adults with obesity. This systematic review suggests that BS induced significant reductions in body weight, fat mass, and fat-free mass in individuals with obesity. Additionally, BS may improve many physical fitness and health indicators. Observed improvements manifest during a distinct period of time. To date, studies on BS and performance have been small in number, nonrandomized in design, and not controlled regarding gender distribution and/or post-surgery follow-up. Future studies should further investigate concerns associated with understanding of BS outcomes to improve these outcomes with potential benefits for quality of life, disability, mortality, morbidity, and overall BS success.

Colorectal Cancer Risk Following Bariatric Surgery in a Nationwide Study of French Individuals With Obesity

Importance

Although bariatric surgery is effective against morbid obesity, the association of this surgery with the risk of colorectal cancer remains controversial.

Objective

To assess whether bariatric surgery is associated with altered risk of colorectal cancer among individuals with obesity.

Design, Setting, and Participants

This retrospective, population-based, multicenter, cohort study based on French electronic health data included 1 045 348 individuals with obesity, aged 50 to 75 years, and free of colorectal cancer at baseline. All inpatients with obesity having data recorded during a hospital stay between 2009 and 2018 by the French national health insurance information system database were followed up for a mean (SD) of 5.3 (2.1) years for those who did not undergo bariatric surgery and 5.7 (2.2) years for those who underwent bariatric surgery. Two groups of patients comparable in terms of age, sex, body mass index, follow-up, comorbidities, and conditions who did or did not undergo surgery were also obtained by propensity score matching.

Exposures

Bariatric surgery (n = 74 131), including adjustable gastric banding, sleeve gastrectomy, gastric bypass; or no bariatric surgery (n = 971 217).

Main Outcomes and Measures

Primary outcome was incident colorectal cancer. Standardized incidence ratios were calculated using age-, sex-, and calendar year-matched colorectal cancer incidence among the general French population during the corresponding years. Secondary outcome was incident colorectal benign polyps.

Results

Among a total of 1 045 348 patients, the mean (SD) age was 57.3 (5.5) years for the 74 131 patients in the surgical cohort vs 63.4 (7.0) years for the 971 217 patients in the nonsurgical cohort. The mean (SD) follow-up was 6.2 (2.1) years for patients who underwent adjustable gastric banding, 5.5 (2.1) years for patients who underwent sleeve gastrectomy, and 5.7 (2.2) years for patients who underwent gastric bypass. In total, 13 052 incident colorectal cancers (1.2%) and 63 649 colorectal benign polyps were diagnosed. The rate of colorectal cancer was 0.6% in the bariatric surgery cohort and 1.3% in the cohort without bariatric surgery. In the latter cohort, 9417 cases were expected vs 12 629 observed, a standardized incidence ratio of 1.34 (95% CI, 1.32-1.36). In the bariatric surgery cohort, 428 cases were expected and 423 observed, a standardized incidence ratio of 1.0 (95% CI, 0.90-1.09). Propensity score-matched hazard ratios in comparable operated vs nonoperated groups were 0.68 (95% CI, 0.60-0.77) for colorectal cancer and 0.56 (95% CI, 0.53-0.59) for colorectal benign polyp. There were fewer new diagnoses of colorectal cancer after gastric bypass (123 of 22 343 [0.5%]) and sleeve gastrectomy (185 of 35 328 [0.5%]) than after adjustable gastric banding (115 of 16 460 [0.7%]), and more colorectal benign polyps after adjustable gastric banding (775 of 15 647 [5.0%]) than after gastric bypass (639 of 20 863 [3.1%]) or sleeve gastrectomy (1005 of 32 680 [3.1%]).

Conclusion and Relevance

The results of this nationwide cohort study suggested that following bariatric surgery, patients with obesity share the same risk of colorectal cancer as the general population, whereas for patients with obesity who do not undergo bariatric surgery, the risk is 34% above that of the general population.

Ventilatory Response at Rest and During Maximal Exercise Testing in Patients with Severe Obesity Before and After Sleeve Gastrectomy

INTRODUCTION

Sleeve gastrectomy (SG) has become a widespread treatment option in patients affected by severe obesity. However, studies investigating the impact of the subsequent weight loss on the ventilatory response at rest and during physical exercise are lacking.

METHODS

This is an observational study on 46 patients with severe obesity (76% females), comparing parameters of ventilatory function 1 month before and 6 months after SG. Patients were first evaluated by resting spirometry and subsequently with an incremental, maximal cardiopulmonary exercise test (CPET) on treadmill.

RESULTS

The important weight loss of 26.35 ± 6.17% of body weight (BMI from 43.59 ± 5.30 to 32.27 ± 4.84 kg/m2) after SG was associated with a significant improvement in lung volumes and flows during forced expiration at rest, while resting ventilation and tidal volume were reduced (all p ≤ 0.001). CPET revealed decreased ventilation during incremental exercise (p < 0.001), with a less shallow ventilatory pattern shown by a lower increase of breathing frequency (∆BFrest to AT p = 0.028) and a larger response of tidal volume (∆TVAT to Peak p < 0.001). Furthermore, a concomitant improvement of the calculated dead space ventilation, VE/VCO2 slope and peripheral oxygen saturation was shown (all p ≤ 0.002). Additionally, the increased breathing reserve at peak exercise was associated with a lower absolute oxygen consumption but improved exercise capacity and tolerance (all p < 0.001).

CONCLUSION

The weight loss induced by SG led to less burdensome restrictive limitations of the respiratory system and to a reduction of ventilation at rest and during exercise, possibly explained by an increased ventilatory efficiency and a decrease in oxygen demands.

Determinants of Cardiorespiratory Fitness After Bariatric Surgery: Insights From a Randomised Controlled Trial of a Supervised Training Program

BACKGROUND

Severely obese patients have decreased cardiorespiratory fitness (CRF) and poor functional capacity. Bariatric surgery-induced weight loss improves CRF, but the determinants of this improvement are not well known. We aimed to assess the determinants of CRF before and after bariatric surgery and the impact of an exercise training program on CRF after bariatric surgery.

METHODS

Fifty-eight severely obese patients (46.1 ± 6.1 kg/m², 78% women) were randomly assigned to either an exercise group (n = 39) or usual care (n = 19). Exercise training was conducted from the 3rd to the 6th months after surgery. Anthropometric measurements, abdominal and mid-thigh computed tomographic scans, resting echocardiography, and maximal cardiopulmonary exercise testing was performed before bariatric surgery and 3 and 6 months after surgery.

RESULTS

Weight, fat mass, and fat-free mass were reduced significantly at 3 and 6 months, without any additive impact of exercise training in the exercise group. From 3 to 6 months, peak aerobic power (V̇O_2peak) increased significantly (P < 0.0001) in both groups but more importantly in the exercise group (exercise group: from 18.6 ± 4.2 to 23.2 ± 5.7 mL/kg/min; control group: from 17.4 ± 2.3 to 19.7 ± 2.4 mL/kg/min; P value, group × time = 0.01). In the exercise group, determinants of absolute V̇O_2peak (L/min) were peak exercise ventilation, oxygen pulse, and heart rate reserve (r² = 0.92; P < 0.0001), whereas determinants of V̇O_2peak indexed to body mass (mL/kg/min) were peak exercise ventilation and early-to-late filling velocity ratio (r² = 0.70; P < 0.0001).

CONCLUSIONS

A 12-week supervised training program has an additive benefit on cardiorespiratory fitness for patients who undergo bariatric surgery.

Development of cancer after bariatric surgery

BACKGROUND

Although bariatric surgery has been associated with a reduction in risk of obesity-related cancer, data on the effect of bariatric interventions on other cancers are limited.

OBJECTIVES

This study aimed to examine the relationship between bariatric interventions and the incidence of various cancers after bariatric surgery.

SETTING

Administrative statewide database.

METHODS

The New York Statewide Planning and Research Cooperative System database was used to identify all adult patients diagnosed with obesity between 2006 and 2012 and patients who underwent bariatric procedures without preexisting cancer diagnosis and alcohol or tobacco use. Subsequent cancer diagnoses were captured up to 2016. Multivariable proportional subdistribution hazard regression analysis was performed to compare the risk of having cancer among obese patients with and without bariatric interventions.

RESULTS

We identified 71,000 patients who underwent bariatric surgery and 323,197 patients without a bariatric intervention. Patients undergoing bariatric surgery were less likely to develop both obesity-related cancer (hazard ratio.91; 95% confidence interval, .85-.98; P = .013) and other cancers (hazard ratio .81; 95% confidence interval, .74-.89; P < .0001). Patients undergoing Roux-en-Y gastric bypass had a lower risk of developing cancers that are considered nonobesity related (hazard ratio .59; 95% confidence interval, .42-.83; P = .0029) compared with laparoscopic sleeve gastrectomy.

CONCLUSIONS

Bariatric surgery is associated with a decreased risk of obesity-related cancers. More significantly, we demonstrated the relationship between bariatric surgery and the reduction of the risk of some previously designated nonobesity-related cancers, as well. Reclassification of nonobesity-related cancers and expansion of bariatric indications for reducing the risk of cancer may be warranted.

Changes in Cardiorespiratory Fitness After Gastric Bypass: Relations with Accelerometry-Assessed Physical Activity

BACKGROUND

Exercise training optimizes cardiorespiratory fitness (CRF) after bariatric surgery, but the effect of spontaneous physical activity is not well known. This study aimed to objectively quantify changes in CRF and habitual physical activity 6 months after bariatric surgery and to examine whether change in CRF was related to change in physical activity.

METHODS

Secondary analyses were performed on data from women who underwent Roux-en-Y gastric bypass (RYGB) between 2010 and 2014. Measurements were performed before and 6 months after RYGB and included V̇O₂peak (graded maximal exercise test on a cycle ergometer), habitual physical activity (Actigraph GT3x accelerometer worn during 7 days), and body composition (DXA absorptiometry). Changes after RYGB were analyzed using Wilcoxon signed-rank test. Relations between change in CRF and change in physical activity were analyzed with Spearman correlations adjusted on age and preoperative BMI.

RESULTS

Forty-five women (median [P₂₅-P₇₅] age, 43.0 [38.0-51.0] year; BMI, 42.6 [40.0-45.5] kg/m²) were included. Mean (SD) weight loss 6 months after RYGB was - 27.5 (7.9) kg (P < 0.001). Absolute V̇O₂peak decreased by 0.35 (0.50) L/min (P < 0.001) and relative V̇O₂peak tended to increase by 1.7 (5.3) mL/kg/min (P = 0.06), both with large inter-individual variability. Based on objective accelerometry data, daily steps and moderate-to-vigorous physical activity increased by 1275 (3164) steps/day and 7.6 (19.3) min/day, respectively (both P < 0.05). Change in absolute V̇O₂peak was positively related to change in moderate-to-vigorous physical activity (r = 0.35; P = 0.03).

CONCLUSIONS

The decrease in absolute CRF observed 6 months after RYGB might be prevented by increasing habitual physical activity.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT01113996.

Impact of Bariatric Surgery on Women Aerobic Exercise Capacity

RATIONALE

Bariatric surgery has a considerable positive effect on weight loss and on metabolic and cardiovascular risks. It has therefore been extensively used this last decade to overcome obesity. However, the impact of this surgery on exercise capacity remains unclear. The aim of this study is to clarify the impact of a surgically induced weight loss on aerobic exercise capacity (VO₂max) in a specific middle-aged female population.

METHODS

Forty-two women with a body mass index > 40 kg/m² (age, 42 ± 13 years; weight, 117 ± 15 kg) underwent blood analyses and a cardiopulmonary exercise test (CPET) before and 1 year after bariatric surgery. CPET was performed on a cycloergometer. The first ventilatory threshold (VT1) was measured according to the V-slope method.

RESULTS

Absolute VO₂max was reduced by 10% after surgery (2.0 ± 0.4 vs 1.8 ± 0.4 l/min, p < 0.01) or increased when corrected for body weight (18 ± 4 vs 23 ± 4 l/min/kg, p < 0.001) or unchanged when expressed as percentage of predicted values (111 ± 21 vs 105 ± 22, p = 0.06). Weight loss did not affect ventilatory or chronotropic response but increased maximal respiratory exchange ratio (RER) (p < 0.001), decreased maximal O₂pulse (p < 0.05) and VT1 in milliliters per minute (p < 0.01). By multivariable analysis, decreased absolute VO₂max after weight loss was associated with increased maximal RER and reduced maximal O₂pulse (p < 0.05, p < 0.01 respectively), possibly related to a muscular mass limitation.

CONCLUSIONS

Weight loss induced by bariatric surgery may reduce aerobic capacity in women in relation to muscle mass loss.

Spiroergometric assessment of cardiorespiratory fitness in subjects with severe obesity: A challenge of reference

BACKGROUND AND AIMS

Severe obesity is associated with poor physical performance but objective data are scarce.

METHODS AND RESULTS

Bicycle spiroergometry data with focus on peak oxygen uptake (V˙O_2,peak) and workload (W_peak) from 476 subjects with severe obesity (BMI ≥ 35.0 kg/m²; 70% women) were analysed. In a first step, V˙O_2,peak values were compared with reference values calculated upon different formulas (Wassermann; Riddle). Thereafter, multivariate regression analyses were performed to identify determinants of cardiorespiratory fitness. Cardiorespiratory fitness reference classes for V˙O_2,peak and W_peak were established by stratifying the sample upon identified determinants. Absolute V˙O_2,peak (1.87 ± 0.47 vs. 2.40 ± 0.59 l/min) and W_peak (131 ± 26 vs. 168 ± 44 W) were lower in women than men (both p<0.001). Same pattern was found for relative V˙O_2,peak and W_peak, respectively (both p < 0.05). In women, measured V˙O_2,peak was lower than predicted by Wasserman (p < 0.001) but not by Riddle (p = 0.961). In men, V˙O_2,peak was lower than calculated by both Wasserman and Riddle formulas (both p ≤ 0.003). Multivariate analyses revealed height and age to be the main determinants of cardiorespiratory fitness in both sexes. Subsequent statistical analyses of calculated reference fitness classes revealed that V˙O_2,peak and W_peak differed between the age- and height-defined groups in both sexes (all p < 0.001).

CONCLUSION

Data indicate that the evaluation of cardiorespiratory fitness in subjects with severe obesity is largely biased by selected references values for comparison. Our newly established reference fitness classes upon height and age might be helpful in the clinical context when dealing with obese patients.

The Impact of Bariatric Surgery on Cardiopulmonary Function: Analyzing VO2 Recovery Kinetics

PURPOSE

To assess cardiopulmonary capacity, autonomic heart function, and oxygen recovery kinetics during exercise testing before and after bariatric surgery.

METHODS

This is a prospective cohort study. Symptom-limited cardiopulmonary exercise testing was performed with 24 patients, 1 week before and 4 months after bariatric surgery. The main variables were maximum oxygen uptake (VO₂ max), the time elapsed until the appearance of the first ventilatory threshold (TLV1), and VO₂ oxygen kinetics during recovery with a 50% reduction in peak oxygen uptake in the recovery period after exercise (50%VO₂RP).

RESULTS

The study demonstrated that the peak VO₂\kg increased significantly after bariatric surgery. When analyzed without adjusting for weight, the peak VO₂ paradoxically and significantly decreased after the surgical procedure (p = 0.007). The exercise time until the anaerobic threshold was longer after surgical procedure than before it (p = 0.001). Regarding post-exercise oxygen recovery kinetics, there was a faster reduction in the peak oxygen uptake after bariatric surgery than before the procedure (p < 0.001).

CONCLUSIONS

There was an obvious cardiac autonomic improvement after surgery. Despite the improvement in exercise tolerance, patients undergoing bariatric surgery had lower maximum oxygen consumption in the analysis not corrected for body weight. The mean VO₂RP before bariatric surgery was 141 s and was 111 s after the surgical procedure (p < 0.001). These results suggest an improvement in the recovery kinetics of oxygen consumption, a novel index of cardiac reserve capacity, on patients undergoing bariatric surgery.

Physical fitness and physical activity in women with obesity: short term effects of sleeve gastrectomy

INTRODUCTION

Introduction: the increase on prevalence of obesity has been linked to a higher number of bariatric surgeries, being sleeve gastrectomy (SG) the most frequent bariatric procedures in the world. However, there are few studies that determine the impact of SG on health's determinants such as physical fitness (PF) and physical activity (PA). Objectives: to describe the changes in PF and PA of patients after SG. Methods: twenty-three women with obesity (mean 36.1 ± 11.1 years old and body mass index [BMI] of 35.1 ± 3.4 kg/m2) were evaluated preoperatively to SG and at one and three months after surgery. An assessment of PF was conducted, including handgrip (HGS) and quadriceps muscle strength (QMS) with dynamometers and cardiorespiratory fitness (CRF) with an ergospirometer. PA was assessed with a three-axis accelerometer. Results: the absolute VO2 peak decreased after the first and third month (p < 0.001) post SG. The VO2 peak relative to body weight showed an increase from baseline after the SG (p = 0.002). After SG, there was a reduction in absolute values for HGS and QMS (p < 0.001) and an increase in relative HGS after three months post-surgery compared to preoperative (p = 0.011), without changes in relative QMS (p = 0.596). No changes in PA were observed. Conclusions: after SG, there is a short term decline on PF when it is expressed on absolute values. However, when it is expressed in relative terms to body weight, some components of PF improve, while others showed no change. There was no modification in PA levels of the participants.

The Amount of Weight Loss Six Months after Bariatric Surgery: It Makes a Difference

BACKGROUND

Bariatric surgery, especially Roux-en-Y gastric bypass (RYGB), has become the most frequently used therapy for morbid obesity.

OBJECTIVES

The aim of this study was to examine the effects of surgically induced weight loss on cardiopulmonary function 6 months after the procedure, as well as the effect of such an intervention on well-known risk factors for cardiovascular diseases.

METHODS

This is a cross-sectional study on 66 morbidly obese patients (BMI ≥40 or ≥35 kg/m2 with present comorbidities), comparing their cardiopulmonary function prior to and 6 months after RYGB surgery.

RESULTS

The substantial amount of weight loss (29.80 ± 13.27 kg) after RYGB surgery was associated with significant reduction of comorbidities, especially diabetes and sedentary lifestyle (p = 0.005 and p = 0.002, respectively). Regarding functional capacity, there was significant increase in peak oxygen uptake (VO2 peak, p = 0.003), duration of exercise testing, metabolic equivalents (exercise time and METs, p < 0.001), and in peak O2 pulse. These findings were particularly pronounced in a group of patients who had lost more than 18% of initial weight.

CONCLUSIONS

Reduction of body weight after RYGB surgery is associated with significantly improved cardiorespiratory function 6 months after surgery, especially in patients who lost more than 18% of their initial body weight. In addition, substantial decreases in body weight were also associated with a reduction of cardiovascular risk factors such as diabetes, smoking, hypertriglyceridemia, and sedentary lifestyle.

Resistance Training and Protein Supplementation Increase Strength After Bariatric Surgery: A Randomized Controlled Trial

OBJECTIVE

Physical activity and dietary regimens to optimize health outcomes after bariatric surgery are not well known. This study aimed to determine whether resistance training with dietary protein supplementation is effective in maintaining body composition and physical fitness after obesity surgery.

METHODS

Seventy-six women with obesity undergoing Roux-en-Y gastric bypass were randomly assigned at the time of surgery to receive either usual care (controls [CON], n = 22), usual care and additional (whey) protein intake (PRO, n = 31), or usual care, additional protein intake, and supervised strength training for 18 weeks (PRO+EX, n = 23). The primary outcome was pre- to 6-month postsurgery change in lean body mass (by dual-energy x-ray absorptiometry). Secondary outcomes included changes in muscle strength (by one-repetition maximum testing).

RESULTS

Loss over time in lean body mass did not differ between groups (CON: mean,-8.8 kg; 95% CI: -10.1 to -7.5 kg; PRO: mean, -8.2 kg; 95% CI: -9.3 to -7.1 kg; PRO+EX: mean, -7.7 kg; 95% CI: -9.0 to -6.5 kg; P = 0.899). The increase in relative lower-limb muscle strength was higher in the PRO+EX group (+0.6 [0.3 to 0.8]) versus +0.1 (-0.1 to 0.4) and +0.2 (0.0 to 0.4) kg/kg body mass in CON and PRO groups, respectively (P = 0.021).

CONCLUSIONS

Loss in muscle strength observed after bariatric surgery can be overcome by resistance training with additional protein intake.

Meta-analysis of the effect of bariatric surgery on physical function

BACKGROUND

Obesity leads to an impairment of physical function that limits the ability to perform basic physical activities affecting quality of life. Literature on the effect of bariatric surgery on physical function is confounding and generally of low quality.

METHODS

A comprehensive search was undertaken using MEDLINE, Scopus (including Embase), CENTRAL, PubMed, SPORTDiscus, Scirus and OpenGrey for published research and non-published studies to 31 March 2017. Studies employing objective measurement and self-reporting of physical function before and after bariatric surgery were included. The magnitude of experimental effect was calculated in terms of the standardized mean difference (MD), and confidence intervals were set at 95 per cent to reflect a significance level of 0·05.

RESULTS

Thirty studies including 1779 patients met the inclusion criteria. Physical function improved after bariatric surgery at 0-6 months (MD 0·90, 95 per cent c.i. 0·60 to 1·21; P < 0·001), more than 6 to 12 months (MD 1·06, 0·76 to 1·35; P < 0·001) and more than 12 to 36 months (MD 1·30, 1·07 to 1·52; P < 0·001). Objective assessment of physical function after bariatric surgery showed improvement at 0-6 months (MD 0·94, 0·57 to 1·32; P < 0·001), more than 6 to 12 months (MD 0·77, 0·15 to 1·40; P = 0·02) and more than 12 to 36 months (MD 1·04, 0·40 to 1·68; P = 0·001). Self-reported assessment of physical function showed similar improvements at 0-6 months (MD 0·80, 0·12 to 1·47; P = 0·02), more than 6 to 12 months (MD 1·42, 1·23 to 1·60; P < 0·001) and more than 12 to 36 months (MD 1·41, 1·20 to 1·61; P < 0·001) after a bariatric procedure.

CONCLUSION

Bariatric surgery improves physical function significantly within 6 months of the procedure and this effect persists over time to 36 months after surgery, whether measured objectively or by self-reporting.

The Effect of Aerobic or Aerobic-Strength Exercise on Body Composition and Functional Capacity in Patients with BMI ≥35 after Bariatric Surgery: a Randomized Control Trial

BACKGROUND

Although previous studies suggested that bariatric surgery is the most effective and sustainable treatment method for morbid obesity in long term, but without changing in lifestyle, maintaining optimal weight loss is almost impossible.

METHODS

Sixty morbid obese patients (BMI ≥ 35) were evaluated before and after 12 weeks of bariatric surgery in order to compare the impact of two different exercise programs on body composition and functional capacity outcomes. Participants were divided into three groups: aerobic (A), aerobic-strength (AS), and control (C) group. Aerobic capacity was assessed with 12-min walk-run test (12MWRT). One-repetition maximum (1RM) test was performed to evaluation upper limb muscle strength. Lower extremity functional capacity was assessed by sit-to-stand test.

RESULTS

Weight, percent body fat (PBF), and fat mass (FM) reduced greater in the trial groups in comparison to the C group (P < 0.05). In the AS group, the reduction of fat-free mass (FFM) was significantly lower than that in the other groups. Mean changes in 12MWRT increased significantly in the intervention groups. The mean change in the sit-to-stand scores was not statistically significant between the three groups. Comparing the intervention groups showed that mean changes in 1RM variables increased in AS group (P = 0.03).

CONCLUSIONS

The data suggests a positive effect of exercise on weight and PBF decrease after surgery, and it leads to significant improvement on aerobic capacity. Moreover, doing resisted exercise caused greater preserving of lean mass.

Assessment of Cardiopulmonary Responses to Treadmill Walking Following Gastric Bypass Surgery

BACKGROUND

Studies that have evaluated cardiopulmonary responses to exercise within the first few months of bariatric surgery have utilized cycle ergometry. However, walking is the most commonly reported mode of both pre- and post-operative PA. The divergent cardiopulmonary responses and metabolic costs of weight-bearing (walking) and non-weight-bearing (cycling) exercises warrant examination of the effects of bariatric surgery on cardiopulmonary responses during walking.

METHODS

Nine women completed a maximal cardiopulmonary exercise test on a treadmill 2 weeks before and 3 months after gastric bypass surgery (GBS). Heart rate (HR), oxygen uptake (VO₂), oxygen pulse (O₂-p), and time to fatigue were compared before and after surgery and between the GBS group and a comparison group of 12 normal-weight (NW) women who completed the same exercise testing protocol.

RESULTS

Time to fatigue increased by ~140 s following GBS (p = 0.018). No other parameter improved during maximal exercise from pre- to post-surgery. Body weight- and fat-free mass-corrected VO₂ and O₂-p at peak exercise differed between the GBS and NW groups before surgery, while only weight-corrected values were different following surgery. These differences disappeared after controlling for body fat percentage.

CONCLUSION

We have demonstrated that weight loss alone was not sufficient to improve select cardiopulmonary fitness measures during treadmill walking in obese females 3 months after GBS. However, we did observe a significant overall improvement in exercise capacity as the GBS group was able to exercise longer, presumably due to significant reductions in body mass and a subsequent reduced metabolic cost of walking.

Physical Fitness and Body Composition Two Years after Roux-En-Y Gastric Bypass in Adolescents

BACKGROUND

We have previously shown promising results 2 years after Roux-en-Y gastric bypass surgery, within the Adolescence Morbid Obesity Surgery study (AMOS). The aim of the current study was to describe the 2-year outcome in cardiorespiratory fitness, body composition, and functional capacity in the Stockholm subset of the AMOS study.

METHODS

Forty-one adolescents (10 male, 31 female, age 14-18 years, body mass index 35-69 kg·m^-2) were included. In addition to anthropometric measurements, participants performed a submaximal bicycle test, 6-min walk test, dual-energy X-ray absorptiometry, and a short interview at baseline, 1 and 2 years after surgery.

RESULTS

Relative improvements in maximal oxygen consumption (VO₂max) per kilogram body mass (+62 %) and per kilogram fat-free mass (+21 %), as well as walking distance (+13 %) were observed after 1 year, and persisted 2 years after surgery. Despite a reduction of fat-free mass (-15 %), absolute VO₂max was maintained across the full group (+8 %, p = ns) and significantly increased in non-smokers. Body mass and fat mass were significantly decreased (-45.4 and -33.3 kg, respectively). Self-reported physical activity was significantly increased, and pain associated with movement was reduced.

CONCLUSIONS

In adolescents with obesity, Roux-en-Y gastric bypass improved VO₂max more than could be explained by fat mass loss alone. In combination with improved functional capacity and body composition, these results suggest that surgery in adolescence might add specific benefits of importance for future health.

Exercise Testing Reveals Everyday Physical Challenges of Bariatric Surgery Candidates

BACKGROUND

Few studies have quantified cardiorespiratory fitness among individuals seeking bariatric surgery. Treadmill testing allows researchers to determine exercise capacity through metabolic equivalents. These findings can assist clinicians in understanding patients' capabilities to carry out various activities of daily living. The purpose of this study was to determine exercise tolerance and the variables associated with fitness, among individuals seeking bariatric surgery.

METHODS

Bariatric surgery candidates completed submaximal treadmill testing and provided ratings of perceived exertion. Each participant also completed questionnaires related to history of exercise, mood, and perceived barriers/benefits of exercise.

RESULTS

Over half of participants reported that exercise was "hard to very hard" before reaching 70% of heart rate reserve, and one-third of participants reported that exercise was "moderately hard" at less than 3 metabolic equivalents (light activity). Body mass index and age accounted for the majority of the variance in exercise tolerance, but athletic history, employment status, and perceived health benefits also contributed. Perceived benefit scores were higher than barrier scores.

CONCLUSION

Categories commonly used to describe moderate-intensity exercise (3-6 metabolic equivalents) do not coincide with perceptions of intensity among many bariatric surgery candidates, especially those with a body mass index of 50 or more.

The Effect of a Muscle Weight-Bearing and Aerobic Exercise Program on the Body Composition, Muscular Strength, Biochemical Markers, and Bone Mass of Obese Patients Who Have Undergone Gastric Bypass Surgery

BACKGROUND

The effect of an exercise program on the body composition, muscular strength (MS), biochemical markers, and bone mineral density (BMD) of individuals undergoing gastric bypass is unclear. We assessed lean mass (LM), MS, bone remodeling markers, and BMD before and after supervised weight-bearing and aerobic exercise training in obese patients who underwent Roux-en-Y gastric bypass (RYGB).

METHODS

This study included 37 obese patients (81.1% women, mean age 38.2 years, mean body mass index 42.4 ± 0.5 kg/m²). Whole body densitometry was used to evaluate pre- and postoperative BMD, total body fat, and LM. Serum calcium, parathyroid hormone, 25-hydroxyvitamin D, and bone remodeling markers were measured. MS was determined through the concentric 10 repetition maximum test. Postoperatively, participants were divided into two groups: the training group, who followed an exercise program (TG, n = 18), and the control group, who did not (CG, n = 19).

RESULTS

After 1 year, the TG showed a lower decrease in total BMD and at the lumbar spine and right hip compared with the CG (p < 0.001). The TG had lower mass reduction and an increase in upper limb LM compared with the CG (both p < 0.05). There was no significant difference between groups in bone markers or calcium metabolism. MS was higher in the TG than the CG (p < 0.05).

CONCLUSION

The supervised exercise program attenuated lumbar spine and right hip BMD loss and improved LM in the arms and overall MS but did not affect bone remodeling.

Comparison of the Effects of Cardiac Rehabilitation Between Obese and Non-obese Patients After Acute Myocardial Infarction

OBJECTIVE

To evaluate the effects of cardiac rehabilitation (CR) on functional capacity in obese and non-obese patients who have suffered acute myocardial infarction (AMI).

METHODS

Overall, 359 patients who have suffered AMI, and were referred for CR after percutaneous coronary intervention from 2010 to 2015 and underwent an exercise tolerance test before and after phase II CR were included in this study. The patients were divided into two groups: obese group with body mass index (BMI) ≥25 kg/m² (n=170; age, 54.32±9.98 years; BMI, 27.52±2.92 kg/m²) and non-obese group with BMI <25 kg/m² (n=189; age, 59.12±11.50 years; BMI 22.86±2.01 kg/m²). The demographic characteristics and cardiopulmonary exercise capacity of all patients were analyzed before and after CR.

RESULTS

There were significant changes in resting heart rate (HR_rest) before and after CR between the obese and non-obese groups (before CR, p=0.028; after CR, p=0.046), but other cardiopulmonary exercise capacity before and after CR was not different between the groups. HR_rest (p<0.001), maximal metabolic equivalents (METs, p<0.001), total exercise duration (TED, p<0.001), and maximal oxygen consumption (VO_2max, p<0.001) improved significantly in the obese and non-obese groups after CR. No difference in the change in the cardiopulmonary exercise capacity rate was detected between the groups.

CONCLUSION

CR may improve functional capacity in patients who suffered AMI regardless of their obesity.

Changes in Functional Mobility and Musculoskeletal Pain After Bariatric Surgery in Teens With Severe Obesity: Teen-Longitudinal Assessment of Bariatric Surgery (LABS) Study

IMPORTANCE

Severe obesity is associated with mobility limitations and higher incidence of multijoint musculoskeletal pain. It is unknown whether substantial weight loss improves these important outcomes in adolescents with severe obesity.

OBJECTIVE

To examine the association of bariatric surgery with functional mobility and musculoskeletal pain in adolescents with severe obesity up to 2 years after surgery.

DESIGN, SETTING, AND PARTICIPANTS

The Teen-Longitudinal Assessment of Bariatric Surgery Study is a prospective, multicenter, observational study, which enrolled 242 adolescents (≤19 years of age) who were undergoing bariatric surgery from March 2007 through February 2012 at 5 US adolescent bariatric surgery centers. This analysis was conducted in November 2015.

INTERVENTIONS

Roux-en-Y gastric bypass (n = 161), sleeve gastrectomy (n = 67), or laparoscopic adjustable gastric band (n = 14).

MAIN OUTCOMES AND MEASURES

Participants completed a 400-m walk test prior to bariatric surgery (n = 206) and at 6 months (n = 195), 12 months (n = 176), and 24 months (n = 149) after surgery. Time to completion, resting heart rate (HR), immediate posttest HR, and HR difference (resting HR minus posttest HR) were measured and musculoskeletal pain concerns, during and after the test, were documented. Data were adjusted for age, sex, race/ethnicity, baseline body mass index (calculated as weight in kilograms divided by height in meters squared), and surgical center (posttest HR and HR difference were further adjusted for changes in time to completion).

RESULTS

Of the 206 adolescents with severe obesity included in the study, 156 were female (75.7%), the mean (SD) age was 17.1 (1.6) years, and the mean (SD) body mass index was 51.7 (8.5). Compared with baseline, significant improvements were observed at 6 months for the walk test time to completion (mean, 376 seconds; 95% CI, 365-388 to 347 seconds; 95% CI, 340-358; P < .01), resting HR (mean, 84 beats per minute [bpm]; 95% CI, 82-86 to 74 bpm; 95% CI, 72-76), posttest HR (mean, 128 bpm; 95% CI, 125-131 to 113 bpm; 95% CI, 110-116), and HR difference (mean, 40 bpm; 95% CI, 36-42 to 34 bpm; 95% CI, 31-37). These changes in time to completion, resting HR, and HR difference persisted at 12 months and 24 months. Posttest HR further improved from 6 months to 12 months (mean, 113 bpm; 95% CI, 110-116 to 108 bpm; 95% CI, 105-111). There were statistically significant reductions in musculoskeletal pain concerns at all points.

CONCLUSIONS AND RELEVANCE

These data provide evidence that bariatric surgery in adolescents with severe obesity is associated with significant improvement in functional mobility and in the reduction of walking-related musculoskeletal pain up to 2 years after surgery.

A randomized trial comparing two interventions to increase physical activity among patients undergoing bariatric surgery

OBJECTIVE

To test the effectiveness of two levels of physical activity interventions before and up to 6½ months after bariatric surgery.

METHODS

Before surgery, individuals completed submaximal exercise testing on a treadmill. After random assignment to standard care, pedometer use, or exercise counseling plus pedometer, participants wore an accelerometer for approximately 2 weeks and returned it to the bariatric center before surgery and 2, 4, and 6 months postoperatively.

RESULTS

Individuals in exercise counseling plus pedometer had higher steps per day and bout minutes of exercise per week than standard care and pedometer use over the course of the study. There were no group differences related to exercise tolerance; however, all groups made significant improvement. There was no statistically significant change in sedentary or light activity nor was there a difference between groups.

CONCLUSIONS

Exercise counseling using pedometers increases physical activity from the perioperative period to 6½ months after surgery, but providing pedometers without professional feedback may not be more effective than standard bariatric surgery treatments. Rapid weight loss increases exercise tolerance and may mask the fitness improvements achieved through a modest physical activity intervention during the first 6 months after bariatric surgery.

Preoperative change in 6-minute walk distance correlates with early weight loss after sleeve gastrectomy

Introduction:

The 6-minute walk test (6MWT) is an objective preoperative measure of functional capacity and response to intervention in patients with heart or lung disease. In bariatric surgery, there has been no reliable preoperative measure predictive of postoperative success. Here we investigated the impact of bariatric surgery on changes in distance traveled in the 6MWT (the 6MWD) and whether preoperative changes in 6MWD correlated with weight change after surgery.

Methods:

This is a retrospective study of consecutive patients in which the 6MWT was performed before and after laparoscopic sleeve gastrectomy for weight loss. 6MWD and total weight were measured. Pearson correlation was used to determine association between variables.

Results:

Of 100 patients who underwent laparoscopic sleeve gastrectomy, 31 patients had a preoperative 6MWT. Thirty patients (97%) were available for follow-up after surgery. Percentage of excess weight loss was 45.7% over an average of 7 months after surgery. There was a weak correlation between the postoperative weight loss and the change in preoperative and postoperative 6MWD (r = 0.28; P = .13). In a subset of patients who demonstrated a change in distance traveled in 2 separate preoperative 6MWD measurements (average 18.5% increase in distance), there was a strong correlation with postoperative weight loss (r = 0.82; P = .02).

Conclusions:

A demonstrated increase in 6MWD before surgery correlates strongly with early postoperative weight loss after laparoscopic sleeve gastrectomy. A multidisciplinary team that includes a physical therapist is useful in preparing bariatric patients for surgery.

Predictors of Lowest Weight and Long-Term Weight Regain Among Roux-en-Y Gastric Bypass Patients

BACKGROUND

Weight loss surgery (WLS) outcomes are poorly understood. This study aimed to evaluate the relationship of well-documented (e.g., health, diet, physical activity) and theoretically relevant variables (e.g., substance use and "food addiction") with both weight nadir and weight regain (WR) following WLS.

METHODS

A sample of 97 Roux-en-Y gastric bypass patients (M time since surgery = 8.86 years) were surveyed about pre- and post-WLS weight, health, self-management behaviors, alcohol problems, and clinical symptoms.

RESULTS

Patients lost a mean of 42 % (SD = 10.71 %) of total weight at weight nadir, but 26 % (SD = 19.66 %) of the lost weight was regained by the time of the survey. Correlates of lower weight nadir and WR differed considerably, with minor overlap. Weight nadir was associated with pre-WLS drug use and post-WLS medical comorbidities. WR, on the other hand, was associated with post-WLS adherence to dietary and physical activity modification. Post-WLS nocturnal eating, depression, and problematic alcohol use were also associated with WR. With all associated variables in regression models, number of post-WLS medical comorbidities (β = -.313, p < 0.01) and post-WLS depression (β = 0.325, p < 0.01) accounted for the most variance and remained as significant predictors of weight nadir and WR, respectively.

CONCLUSIONS

While weight nadir was associated with relatively few and largely nonmodifiable variables, WR was significantly associated with adherence-related behaviors, mood symptoms, and pathological patterns of food and alcohol use, all of which are potentially modifiable. These findings underscore the importance of long-term behavioral and psychosocial monitoring after surgery.

Changes in physical activity behaviour and physical function after bariatric surgery: a systematic review and meta-analysis

Although physical activity performed after bariatric surgery is associated with enhanced weight loss outcomes, there is limited information on patients' physical activity behaviour in this context. This systematic review and meta-analysis assessed pre-operative to post-operative changes in physical activity and physical function outcomes among obese adults undergoing bariatric surgery. A total of 50 studies met inclusion criteria with 26 papers reporting data for meta-analysis. Increases in both objectively recorded and self-reported physical activity at 12 months were demonstrated. Studies indicated that there was a shift towards a greater amount of active time, but of a lower intensity within the first 6 months of bariatric surgery, suggested by a reduction in moderate to vigorous physical activity but an increase in step count. A standardized mean difference (SMD) of 1.53 (95% CI: 1.02-2.04) based on nine studies indicated improved walking performance at 12 months. Similarly, analysis of five studies demonstrated increased musculoskeletal function at 3-6 months (SMD: 1.51; 95% CI: 0.60-2.42). No relationship was identified between changes in weight and walking performance post-surgery. More studies assessing physical activity, physical function and weight loss would help understand the role of physical activity in optimizing post-operative weight and functional outcomes.

Comprehensive assessment of physical functioning in bariatric surgery candidates compared with subjects without obesity

BACKGROUND

Obesity appears to be associated with reduced physical performance, but comprehensive assessments of physical functioning are lacking in subjects with severe obesity, in particular in comparison with subjects without obesity. This precludes an objective assessment of the degree of impairment.

OBJECTIVE

To compare motor skills and cardiopulmonary fitness between subjects with severe obesity (OB) (i.e., candidates for bariatric surgery) and control subjects without obesity (non-OB).

SETTING

Cantonal Hospital, Switzerland.

METHODS

Flexibility, movement speed, balance, maximal isometric strength, and cardiopulmonary fitness were tested in 45 OB (body mass index: 42.6±.9 kg/m(2); age: 35±1.7 years; 33 women) and 32 non-OB (body mass index: 23±.4 kg/m(2); age: 38.5±2.1 years; 25 women) subjects.

RESULTS

In comparison with the non-OB group, the OB group showed reduced shoulder flexibility (P<.001) but comparable hamstrings flexibility (P = .3). Speed-related tasks (i.e., timed up-and-go test and timed lying-to-standing test) indicated that the OB group was slower than the non-OB group (all P<.007). Strength-related tasks indicated a greater absolute back muscle and knee-extensor strength (all P<.002) in the OB group with no difference in knee-flexor strength (both P>.8). However, when related to weight, the OB group showed reduced maximal strength (all P<.002). Bicycle spiroergometry indicated that absolute oxygen consumption at peak exercise and at the anaerobic threshold did not differ between groups (both P>.06). Related to weight, however, values were lower in the OB than in the non-OB group (both P< .001).

CONCLUSION

Data indicate a differential pattern of functional impairment in bariatric surgery candidates compared with subjects without obesity. These findings might help to establish tailored intervention protocols to improve physical performance in such subjects.

Impact of bariatric surgery on physical functioning in obese adults

Obesity is associated with a profound impairment in the ability to perform the basic physical activities required for everyday function. This impacts on quality of life and contributes to disability. Bariatric surgery leads to weight loss and metabolic improvements in severe obesity; however, less is known about its effect on physical functioning. This narrative review summarizes current evidence on the effect of bariatric surgery on this outcome with a consideration of the mechanisms involved. Nine longitudinal observational studies reporting objective measures of physical functioning were identified. Inclusion criteria, follow-up time and outcomes reported varied considerably between studies and sample sizes were small. They all showed a significant improvement in performance following surgery despite variations in baseline patient characteristics. Additionally, six studies were found in which subjects were subjected to exercise testing protocols. Performance of the test protocol improved in all. Where reported, peak oxygen uptake related to body weight improved; however, absolute values were either unchanged or decreased. In conclusion, observational evidence suggests that patients' physical functioning improves following bariatric surgery. More evidence is required regarding mechanisms involved; however, it may be due to improved efficiency in performing activities as opposed to absolute improvements in cardiorespiratory or muscle function.

When obesity and chronic obstructive pulmonary disease collide. Physiological and clinical consequences

In many parts of the world, the prevalence of both chronic obstructive pulmonary disease (COPD) and obesity is increasing at an alarming rate. Such patients tend to have greater respiratory symptoms, more severe restriction of daily activities, poorer health-related quality of life, and greater health care use than their nonobese counterparts. Physiologically, increasing weight gain is associated with lung volume reduction effects in both health and disease, and this should be considered when interpreting common pulmonary function tests where lung volume is the denominator, such as FEV1/FVC and the ratio of diffusing capacity of carbon monoxide to alveolar volume, or indeed when evaluating the physiological consequences of emphysema in obese individuals. Contrary to expectation, the presence of mild to moderate obesity in COPD appears to have little deleterious effect on respiratory mechanics and muscle function, exertional dyspnea, and peak symptom-limited oxygen uptake during cardiopulmonary exercise testing. Thus, in evaluating obese patients with COPD reporting activity restriction, additional nonpulmonary factors, such as increased metabolic loading, cardiocirculatory impairment, and musculoskeletal abnormalities, should be considered. Care should be taken to recognize the presence of obstructive sleep apnea in obese patients with COPD, as effective treatment of the former condition likely conveys an important survival advantage. Finally, morbid obesity in COPD presents significant challenges to effective management, given the combined effects of erosion of the ventilatory reserve and serious metabolic and cardiovascular comorbidities that collectively predispose to an increased risk of death from respiratory failure.

Aspects of Exercise before or after Bariatric Surgery: A Systematic Review

BACKGROUND

Bariatric surgery has a considerable effect on weight loss. A positive relation of exercise and weight loss has been described before. However, the mode of exercise and its timing pre- or postoperatively or a combination remains unclear.

METHODS

A multi-database search was conducted. Identified articles were reviewed on description of exercise, timing around a bariatric intervention, and outcome. Methodological quality of the included studies was rated using the Physiotherapy Evidence Database scale. A Cohen’s kappa score assessed the level of agreement. Outcome measurements were improvement of anthropometric and physical fitness variables, operation related complications, weight regain, and quality of life.

RESULTS

A total of 8 prospective studies were included. Four focused on training before and 4 on training after a bariatric procedure. Details of exercises varied from 45 min treadmill up to full descriptive programs. Supervision was frequently included. Significant improvement was encountered for biometric results physical fitness variables.

CONCLUSION

In the majority of reports on exercising in a (future) bariatric population, positive effects on anthropometrics, cardiovascular risk factors and physical fitness were described. However, the results were not unanimous, with a wide range of exercise programs and perioperative timing, therefore hampering adequate practical guidance.

Functioning of obese individuals in pre- and postoperative periods of bariatric surgery

BACKGROUND

Obesity is a pathologic condition that causes functional incapacity, with reduction of quality of life and life expectancy and an increase in mortality. Bariatric surgery is indicated to alleviate associated comorbidities and increase physical capacity. The objective of this work was to evaluate the functional capacity of patients with morbid obesity before and after (3 months) bariatric surgery.

METHODS

This was a cross-sectional study involving 67 patients, where 61 were women and six men, with a mean age of 38 ± 10 years and mean BMI of 50.45 ± 8.5 kg/m2. All patients were assessed before surgery and 3 months afterwards. The following assessments were performed: 6-min walk test (6MWT), functional independence measure (FIM), and test for risk of falling and transfer capacity, called the timed up-and-go test.

RESULTS

The study demonstrated a reduction in parameters evaluated in 6MWT with a statistically significant difference at two times (rest and final) when evaluated before and after bariatric surgery (p < 0.001). In relation to the FIM and timed up-and-go test, the patients showed a statistically significant improvement (p < 0.001) for both when comparing the tasks evaluated at the pre- and postoperative moments.

CONCLUSIONS

Obesity has an impact on the functioning and quality of life of patients. We observed an improvement in all instruments used for assessment before and after bariatric surgery, where a linear component was demonstrated in relation to diminution of body mass index and functioning.

Differential changes in exercise performance after massive weight loss induced by bariatric surgery

BACKGROUND

Exercise performance and pulmonary function are often impaired in severely obese subjects. Bariatric surgery represents the most effective therapy for severe obesity, but data on changes in exercise performance after massive weight loss induced by bariatric surgery have rarely been assessed so far.

METHODS

Exercise performance was obtained by bicycle spiroergometry in 18 severely obese patients before and at least 1 year after bariatric surgery. Additionally, pulmonary function was assessed by spirometry.

RESULTS

BMI was reduced from 46.3 ± 1.6 to 33.5 ± 1.4 kg/m(2) after surgery. Pulmonary function (forced expiratory volume within 1 s; inspiratory vital capacity) improved after weight loss (both p ≤ 0.01). At peak exercise, heart rate (HR) peak, absolute oxygen uptake (VO(2)) peak, and load peak did not differ between both assessments (all p > 0.25). However, relative (related to actual body weight) VO(2) peak and workload peak were higher after than before surgery (both p ≤ 0.005), while gross efficiency peak and ventilatory equivalent peak remained unchanged (both p > 0.30). At anaerobic threshold (AT), patients showed lower HR AT and absolute VO(2) AT after than before surgery (both p < 0.05), while absolute workload AT did not differ (p = 0.58). In turn, relative VO(2) AT did not change (p = 0.30), whereas relative workload AT was higher after surgery (p = 0.04). Also, ventilatory efficiency AT and gross efficiency AT tended to be improved (both p = 0.08). Before surgery, the patients performed 27.0 % of VO(2) peak above their AT, while this fraction increased to 35.3 % (p = 0.006).

CONCLUSIONS

Results indicated differential changes in exercise performance, with the relative but not the absolute peak performance being improved after massive weight loss. Interestingly, anaerobic exercise tolerance was markedly improved after surgery.