Clinical trial demonstrates exercise following bariatric surgery improves insulin sensitivity

Follow-up after bariatric surgery: A review

Bariatric surgery is becoming increasingly popular in the treatment of severely obese patients who failed to lose weight with the help of non-surgical interventions. Such patients are at increased risk for premature death, type 2 diabetes, high blood pressure, gallstones, coronary heart disease, dyslipidemia, some cancers, anxiety, depression, and degenerative joint disorders. Although bariatric surgery appears to be the most effective and durable treatment option for obesity, it is associated with a number of surgical and medical complications. These include a range of conditions, of which dumping syndrome and malnutrition due to malabsorption of vitamins and minerals are the most common. To achieve better surgery outcomes, a number of postsurgical strategies must be considered. The aim of this review was to describe possible complications, ailments, and important moments in the follow-up after bariatric surgery. Adequate lifelong monitoring is crucial for the achievement of long-lasting goals and reduction of post-bariatric complications.

Physical Exercise following bariatric surgery in women with Morbid obesity: Study protocol clinical trial (SPIRIT compliant)

BACKGROUND

Severe and morbid obesity are increasing globally, particularly in women. As BMI increases, the likelihood of anovulation is higher. The primary aim of the EMOVAR clinical trial is to examine, over the short (16 weeks) and medium (12 months) term, the effects of a supervised physical exercise program (focused primarily on aerobic and resistance training) on ovarian function in women with severe/morbid obesity who have undergone bariatric surgery. Secondary objectives are to examine the effects of the intervention on chronic inflammation, insulin resistance, arterial stiffness, physical fitness, and health-related quality of life.

METHODS

This is a randomized controlled trial in which ∼40 female bariatric surgery patients, aged between 18 and 45 years old, will be included. Participants assigned to the experimental group will perform a total of 48 sessions of supervised concurrent (strength and aerobic) training (3 sessions/week, 60 min/session) spread over 16 weeks. Patients assigned to the control group will receive lifestyle recommendations. Outcomes will be assessed at baseline, week 16 (i.e., after the exercise intervention) and 12 months after surgery. The primary outcome is ovarian function using the Sex-Hormone Binding Globuline, measured in serum. Secondary outcomes are serum levels of anti-mullerian hormone, TSH, T4, FSH, LH, estradiol, prolactine, and free androgen index, as well as oocyte count, the diameters of both ovaries, endometrial thickness, and uterine arterial pulsatility index (obtained from a transvaginal ultrasound), the duration of menstrual bleeding and menstrual cycle duration (obtained by personal interview) and hirsutism (Ferriman Gallwey Scale). Other secondary outcomes include serum markers of chronic inflammation and insulin resistance (i.e., C-reactive protein, interleukin 6, tumor necrosis factor-alpha, leptin, glomerular sedimentation rate, glucose, insulin and the HOMA-IR), arterial stiffness, systolic, diastolic and mean blood pressure, body composition, and total weight loss. Physical fitness (including cardiorespiratory fitness, muscular strength, and flexibility), health-related quality of life (SF-36 v2) and sexual function (Female Sexual Function Index) will also be measured.

DISCUSSION

This study will provide, for the first time, relevant information on the effects of exercise training on ovarian function and underlying mechanisms in severe/morbid obese women following bariatric surgery.

TRIAL REGISTRATION NUMBER

ISRCTN registry (ISRCTN27697878).

Ongoing Inconsistencies in Weight Loss Reporting Following Bariatric Surgery: a Systematic Review

Weight loss is the primary outcome following bariatric surgery; however, its documentation within current literature is heterogeneous and poorly defined, limiting meaningful comparison between studies. Randomized controlled trials from 2012 to 2016 were identified using the Medline database through "Gastric bypass OR sleeve gastrectomy AND weight" search terms. A total of 73 studies with 5948 patients were included. Reporting of preoperative weight was done primarily using mean body mass index (BMI) (87.7%) and mean weight (65.8%). Postoperative weight reporting was more variable, with the most frequently reported measure being mean postoperative BMI (71.2%). Overall, nearly one third of all bariatric literature contained discrepancies that precluded meaningful meta-analysis. Reporting of weight loss following bariatric surgery is becoming increasingly diverse for both pre- and post-operative outcomes. Ongoing heterogeneity will continue to act as a barrier to meaningful comparison of bariatric outcomes until standardized reporting practices become adopted.

[there any association of metabolic disturbances with joint destruction and pain?]

Osteoarthritis and type 2 diabetes mellitus represent two the most common chronic diseases. They possess many shared epidemiologic traits, have common risk factors, and embody heterogeneous multifactorial pathologies, which develop due to interaction of genetic an environmental factors. In addition, these diseases are often occurring in the same patient. In spite of the differences in clinical manifestation both diseases have similar disturbances of cellular metabolism, primarily associated with ATP production and utilization. The review discusses molecular mechanisms determining pathophysiological processes associated with glucose and lipid metabolism as well as the means aiming to alleviate the disturbances of energy metabolism as a new a therapeutic approach.

Fitness, Strength and Body Composition during Weight Loss in Women with Clinically Severe Obesity: A Randomised Clinical Trial

INTRODUCTION

To determine whether combined exercise training with an energy-restricted diet leads to improved physical fitness and body composition when compared to energy restriction alone in free-living premenopausal women with clinically severe obesity.

METHODS

Sixty premenopausal women (BMI of 40.4 ± 6.7) were randomised to energy restriction only (ER) or to exercise plus energy restriction (EXER) for 12 months. Body composition and fitness were measured at baseline, 3, 6 and 12 months.

RESULTS

VO2 peak improved more for EXER compared to ER at 3 (mean difference ± SEM 2.5 ± 0.9 mL ∙ kg-1 ∙ min-1, p = 0.006) and 6 (3.1 ± 1.2 mL ∙ kg-1 ∙ min-1, p = 0.007) but not 12 months (2.3 ± 1.6 mL ∙ kg-1 ∙ min-1, p = 0.15). Muscle strength improved more for EXER compared to ER at all time points. No differences between groups for lean mass were observed at 12 months.

CONCLUSION

Combining exercise training with an energy-restricted diet did not lead to greater aerobic power, total body mass, fat mass or limit lean body mass loss at 12 months when compared to energy restriction alone for premenopausal women with clinically severe obesity in free-living situations. Future research should aim to determine an effective lifestyle approach which can be applied in the community setting for this high-risk group.

Effects of Exercise on the Body Composition and Lipid Profile of Individuals with Obesity: A Systematic Review and Meta-Analysis

Background

Numerous researchers have worked to develop treatments for obesity; however, the prevalence of obesity continues to increase in many countries. Moreover, the effects of physical activity and exercise on obesity remain unclear. Therefore, it is necessary to perform a systematic review and meta-analysis to assess the relationship between exercise and obesity using mediator variables such as the mode of exercise.

Methods

Our review focuses on research tracking the effects of exercise on obesity conducted from 2007 to 2016 and available in any of three databases: Embase, PubMed, and EBSCO Academic Search Premier. The keywords used in the search were “exercise and obesity” and “exercise and obese.”

Results

The average size of the effects that exercise interventions have on body mass index (standardized mean difference [SMD], 0.533), waist circumference (SMD, 0.666), total cholesterol (SMD, 0.721), and triglyceride (TG; SMD, 0.603) were medium or larger. Exercise had greater effects on the outward appearance of obesity (body mass index, waist circumference) than on its practical factors (weight, % body fat). The effect of exercise on TG (SMD, 0.603) was larger than that on low-density lipoprotein (SMD, 0.406) and high-density lipoprotein (SMD, −0.222). Exercise duration (weeks of exercise) and intensity correlate better than exercise time (minutes per week) with a large and consistent improvement in adult obesity.

Conclusion

We suggest that individuals with obesity should exercise consistently to achieve significant improvements in their health.

Skeletal muscle fat in individuals with rheumatoid arthritis compared to healthy adults

OBJECTIVE

To compare skeletal muscle fat (SMF), intermuscular adipose tissue (IMAT) and subcutaneous adipose tissue (SAT) between individuals with rheumatoid arthritis (RA), and healthy individuals of the same age, and healthy individuals at least 10 years older than those with RA.

METHODS

Two cross-sectional studies. In the first study, RA subjects were matched by age, sex, and BMI with healthy adults. In the second, RA subjects were matched by sex and BMI to adults 10-20 years older. SMF, IMAT and SAT were measured with Computed Tomography images of the mid-thigh region. We used parametric or non-parametric related-sample tests to compare fat accumulation between RA subjects and healthy adults.

RESULTS

In the first study SMF was significantly higher in the RA cohort compared to their age-matched healthy counterparts (mean difference = -3.5 HU (95% -6.2, -0.9), p = 0.011), but IMAT and SAT were similar between cohorts. In the second study, SMF, IMAT and SAT were not significantly different between the RA and matched older healthy cohorts. In both studies, there were no significant differences in mid-thigh muscle area between RA subjects and healthy adults.

CONCLUSION

SMF accumulation in RA was higher than in healthy individuals of similar age, sex, BMI. Accumulation of fat within and around the muscles in RA was not different compared to the matched healthy older individuals, indicating that muscle fat accumulation in RA might mimic a pattern not different from healthy aging.

Plasma lactate as a marker of metabolic health: Implications of elevated lactate for impairment of aerobic metabolism in the metabolic syndrome

BACKGROUND

Fasting lactate is elevated in metabolic diseases and could possibly be predictive of the risk of developing the metabolic syndrome.

METHODS

Plasma samples were analyzed for fasting lactate to compare lean subjects, nondiabetic subjects with severe obesity, and metabolically impaired subjects. Subjects with severe obesity were studied 1 week before and 1 week to 9 months after gastric bypass surgery. Subjects with components of the metabolic syndrome were studied before and after 6 months of an exercise intervention.

RESULTS

Metabolically impaired subjects had higher fasting lactate concentrations (P < .0001) and respond to a glucose or insulin challenge with higher lactates than non-obese subjects (P < .004). Lactate was significantly reduced a week after gastric bypass surgery (P < .05) and further reduced 1 to 9 months after surgery (0.95 ± 0.04 mM in non-obese, 1.26 ± 0.12 mM in subjects with severe obesity, and 0.68 ± 0.03 mM 1-3 months after gastric bypass). Six months of chronic exercise resulted in a 16% reduction (P = .028) in fasting lactate.

CONCLUSION

Fasting plasma lactate was elevated in obese subjects with the metabolic syndrome compared with healthy lean individuals. Lactate was reduced by exercise and bariatric surgery, interventions that improve metabolic health and risk for subsequent disease. The results of this study and those previously published by our research group suggest that elevated lactate may be caused by an impairment in aerobic metabolism and may offer a metric assessing the severity of the metabolic syndrome.

Physical Activity Associates with Muscle Insulin Sensitivity Postbariatric Surgery

PURPOSE

Bariatric surgery is considered as an effective therapeutic strategy for weight loss in severe obesity. Remission of type 2 diabetes is often achieved after the surgery. We investigated whether increase in self-reported habitual physical activity associates with improved skeletal muscle insulin sensitivity and reduction of fat depots after bariatric surgery.

METHODS

We assessed self-reported habitual physical activity using Baecke questionnaire in 18 diabetic and 28 nondiabetic patients with morbid obesity (median age, 46 yr; body mass index, 42.0 kg·m) before and 6 months after bariatric surgery operation. Insulin-stimulated femoral muscle glucose uptake was measured using fluorodeoxyglucose positron emission tomography method during hyperinsulinemia. In addition, abdominal subcutaneous and visceral fat masses were quantified using magnetic resonance imaging and liver fat content using magnetic resonance spectroscopy. Also, serum proinflammatory cytokines were measured.

RESULTS

Patients lost on average 22.9% of weight during the follow-up period of 6 months (P < 0.001). Self-reported habitual physical activity level increased (P = 0.017). Improvement in skeletal muscle insulin sensitivity was observed only in those patients who reported increase in their physical activity postoperatively (P = 0.018). The increase in self-reported physical activity associated with the loss of visceral fat mass (P = 0.029). Postoperative self-reported physical activity correlated also positively with postoperative hepatic insulin clearance (P = 0.02) and tended to correlate negatively with liver fat content (P = 0.076). Postoperative self-reported physical activity also correlated negatively with serum TNFα, methyl-accepting chemotaxis protein and interleukin 6 levels.

CONCLUSIONS

Self-reported physical activity is associated with reversal of skeletal muscle insulin resistance after bariatric surgery as well as with the loss of visceral fat content and improved postoperative metabolism in bariatric surgery patients.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT00793143 (SLEEVEPASS), NCT01373892 (SLEEVEPET2).

Effects of a Pre-surgery Supervised Exercise Training 1 Year After Bariatric Surgery: a Randomized Controlled Study

BACKGROUND

We have previously reported on the benefits of Pre-Surgical Exercise Training (PreSET) on physical fitness and social interactions in subjects awaiting bariatric surgery (BS). However, data are needed to know whether these benefits are maintained post-BS.

OBJECTIVES

The purpose of this paper was to evaluate the effect of PreSET on physical activity (PA) level, physical fitness, PA barriers, and quality of life (QoL) 1 year (1-Y) after BS.

METHODS

Of the 30 participants randomized into two groups (PreSET and usual care), 25 were included in the final analysis. One year after BS, time spent in different PA intensities and number of steps were assessed with an accelerometer. Before BS and until 1-Y after BS, physical fitness was assessed with symptom-limited cardiac exercise test, 6-min walk test (6MWT), and sit-to-stand, half-squat, and arm curl tests. QoL, PA barriers, and PA level were evaluated with questionnaires.

RESULTS

The number of steps (7460 vs 4287) and time spent in light (3.2 vs 2.2 h/day) and moderate (0.6 vs 0.3 h/day) PA were higher in the PreSET group 1-Y after BS. The changes in 6MWT heart cost (1.3 vs 0.6 m/beats/min), half-squat test (38.8 vs 10.3 s), and BMI (- 16.8 vs - 13.5 kg/m²) were significantly greater in the PreSET group compared to those in the usual care group. No other significant difference between groups was observed.

CONCLUSION

The addition of the PreSET to individual lifestyle counseling seems effective to improve PA level and submaximal physical fitness 1-Y after BS. Studies with larger cohorts are now required to confirm these results. The trial was registered at clinicaltrials.gov (NCT01452230).

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.

Exercise and Bariatric Surgery: An Effective Therapeutic Strategy

Exercise is a clinically effective adjunct therapy with the potential to promote long-term weight loss maintenance for bariatric surgery patients.

The long-term efficacy of bariatric surgery is not entirely clear, and weight regain and diabetes relapse are problems for some patients. Exercise is a feasible and clinically effective adjunct therapy for bariatric surgery patients. We hypothesize that exercise is also a critical factor for long-term weight loss maintenance and lasting remission of type 2 diabetes.

Effectiveness of exercise training after bariatric surgery-a systematic literature review and meta-analysis

We aimed to conduct a systematic review and meta-analysis of controlled trials assessing exercise training programs in patients with obesity undergoing bariatric surgery. We systematically searched exercise training studies performed after bariatric surgery published up to June 2017. Studies reporting changes in body composition, physical fitness, functional capacity, objectively measured physical activity, quality of life or relevant health outcomes were included. The review protocol is available from PROSPERO (CRD42017069380). Meta-analyses were conducted using random-effects models when data were available from at least five articles. Twenty articles were included, describing 16 exercise training programs, of which 15 were included in the meta-analysis. Overall, exercise training was associated with higher weight loss (mean difference: -2.4 kg, 95% CI: -4.2; -0.6, I²  = 49%, n = 12), higher fat mass loss (-2.7 kg, 95% CI: -4.5; -1.0, I²  = 50%, n = 8) and improved VO₂ max and functional walking (standardized mean difference: 0.86, 95% CI: 0.29; 1.44, I²  = 57%, n = 6; 1.45, 95% CI: 0.32; 2.58, I²  = 89%, n = 6, respectively). Exercise training was not associated with lean body mass changes. In conclusion, exercise training programs performed after bariatric surgery were found effective to optimize weight loss and fat mass loss and to improve physical fitness, although no additional effect on lean body mass loss was found.

Effect of physical exercise on weight loss and physical function following bariatric surgery: a meta-analysis of randomised controlled trials

OBJECTIVES

We performed a meta-analysis of all of the available randomised controlled trials (RCTs) to investigate whether physical exercise contributes to weight loss or physical function improvement in adults receiving bariatric surgery.

METHODS

We searched PubMed, Embase, the Cochrane Library, OVID and the CINAHL up through May 2018. RCTs that assigned adults with obesity to either an exercise training group or a no-exercise group after bariatric surgery were included. The primary outcomes were weight loss and physical function. Study bias was assessed using the Cochrane risk of bias tool, and the quality of evidence was assessed using GRADEpro.

RESULTS

A total of eight studies met the inclusion criteria (n=347 participants). Most of the studies carried a low risk of bias due to randomisation and blinding. Compared with those without exercise intervention after surgery, patients engaging in physical exercise were associated with greater weight loss (weighted mean difference (WMD) -1.94 kg; 95% CI -3.18 to -0.69; n=8) and longer 6 min walk distance (6MWD; WMD29.67 m; 95% CI 25.97 to 33.37; n=2) during follow-up. By subgroup analyses, the additional weight loss in exercise group was related to the starting time and type of exercise: patients engaging in exercise 1 year or more after surgery and patients received aerobic-resistance exercise experienced more weight loss. Besides, patients in exercise training group also had lower systolic blood pressure and resting heart rate after surgery. The quality of evidence for these outcomes was moderate to very low.

CONCLUSIONS

Physical exercise after bariatric surgery provides 1.94 kg additional weight loss and 29.67 m longer 6MWD compared with surgery alone. Moreover, engaging in exercise 1 year or more after surgery, and a combined aerobic and resistance training programme may result in greater weight loss.

Functional and systemic effects of whole body electrical stimulation post bariatric surgery: study protocol for a randomized controlled trial

Background

Obesity represents a major public health problem and is the fifth leading risk factor for mortality. Morbid obesity is associated with chronic systemic inflammation which increases the risk of comorbidities. Bariatric surgery (BS) is considered an effective intervention for obese patients. However, BS is associated with dietary restriction, potentially limiting physical activity. Whole-body neuromuscular electrical stimulation (WBS) could represent an innovative option for the rehabilitation of BS patients, especially during the early postoperative phase when other conventional techniques are contraindicated. WBS is a safe and effective tool to combat sarcopenia and metabolic risk as well as increasing muscle mass, producing greater glucose uptake, and reducing the proinflammatory state. Therefore, the objective of this study is to evaluate the effects of WBS on body composition, functional capacity, muscle strength and endurance, insulin resistance, and pro- and anti-inflammatory circulating markers in obese patients undergoing BS.

Methods/design

The present study is a randomized, double-blind, placebo-controlled, parallel groups clinical trial approved by the Ethics Committee of our Institution. Thirty-six volunteers (body mass index (BMI) > 35 kg/m²) between 18 and 45 years of age will be randomized to the WBS group (WBSG) or control (Sham) group (ShamG) after being submitted to BS. Preoperative assessments will include maximal and submaximal exercise testing, body composition, blood inflammatory markers, and quadriceps strength and endurance. The second day after discharge, body composition will be evaluated and a 6-min walk test (6MWT) will be performed. The WBS or Sham protocol will consist of 30 daily sessions for 6 consecutive weeks. Afterwards, the same assessments that were performed in the preoperative period will be repeated.

Discussion

Considering the important role of WBS in skeletal muscle conditioning and its value as an aid in exercise performance, the proposed study will investigate this technique as a tool to promote early rehabilitation in these patients, and as a strategy to enhance exercise capacity, weight loss, and peripheral muscle strength with positive systemic effects. The present study is still ongoing, and data will be published after its conclusion.

Trial registration

REBEC, RBR-99qw5h. Registered on 20 February 2015.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2844-8) contains supplementary material, which is available to authorized users.

Effects of 6 months supervised physical training on muscle strength and aerobic capacity in patients undergoing Roux-en-Y gastric bypass surgery: a randomized controlled trial

Obesity and physical inactivity are major health problems. Roux-en-Y gastric bypass (RYGB) surgery results in significant weight loss and reduces obesity-related morbidity and mortality. Physical activity lowers the risk of cardiovascular disease and premature death. The aims of this study were to elucidate the effects of RYGB followed by 6 months of supervised physical training on physical capacity. In a randomized controlled trial, 60 participants eligible for RYGB were randomized 6 months post-surgery to either two weekly physical training sessions for 26 weeks (INT) or a control group (CON). Aerobic capacity (VO₂ max), muscle strength (MS) of the shoulder and hip and physical function were measured pre-surgery and 6, 12 and 24 months post-surgery. RYGB per se decreased MS in all tested muscle groups, had no effects on VO₂ max but improved physical function. After the intervention, INT had a significant 0.33 L min^-1 increase in VO₂ max compared to CON (95% CI: 0.07-0.57, P = 0.013). Furthermore, MS in the hip adductor increased significantly with 13 N (95% CI: 3.6-22.4, P = 0.007) and a between-group difference was found in the Stair Climb Test (0.46 repetitions [95% CI: 0.02-0.91, P = 0.042]). The effects were not maintained at follow-up. Supervised physical training following RYGB improved VO₂ max, hip MS and physical function, but the positive effects were not maintained at follow-up. While activities of daily life may become easier as a result of RYGB, the observed extensive post-operative loss of MS requires more attention to increase the patient's physical capacity prospectively.

Supervised Physical Training Improves Weight Loss After Roux-en-Y Gastric Bypass Surgery: A Randomized Controlled Trial

OBJECTIVE

Bariatric surgery results in significant weight loss and reduces cardiovascular morbidity. However, a large variation in postsurgery weight loss is seen. Physical activity promotes weight loss in nonsurgically treated subjects with obesity. The aim of this study was to investigate the effects of 6 months of supervised physical training following Roux-en-Y gastric bypass surgery (RYGB) on body weight and cardiovascular risk markers.

METHODS

Sixty participants eligible for RYGB were included. Six months post surgery, the participants were randomly assigned to either twice-weekly supervised physical training sessions in a fitness center (INT) or a control group (CON) for 26 weeks. Before surgery and 6, 12, and 24 months after surgery, the participants underwent an examination program that included anthropometric measurements, blood pressure, heart rate, blood samples, and an abdominal computed tomography scan.

RESULTS

RYGB significantly reduced body weight and improved cardiovascular risk markers (all P < 0.01). The supervised physical training intervention resulted in a 4.2-kg (CI: -0.2 to -8.3 kg) lower body weight in INT compared with CON at the study end (P = 0.042). The high-density lipoprotein concentration was significantly higher in INT than in CON at the termination of the intervention, but this was not maintained at the 24-months examination.

CONCLUSIONS

Physical training following RYGB improves weight loss and cardiovascular health.

Bariatric Surgery Resistance: Using Preoperative Lifestyle Medicine and/or Pharmacology for Metabolic Responsiveness

Bariatric surgery is an effective and durable treatment for individuals with obesity and its associated comorbidities. However, not all patients meet weight loss and/or cardiometabolic goals following bariatric surgery, suggesting that some people are bariatric surgery resistant. The reason for this resistance is unclear, but potential factors, such as adiposity-derived inflammation, insulin resistance, hyperglycemia, and aerobic fitness prior to surgery, have been related to blunted surgery responsiveness. Exercise, diet, and/or pharmacology are effective at reducing inflammation and improving insulin action as well as physical function. Herein, we present data that supports the novel hypothesis that intervening prior to surgery can enhance disease resolution in people who are resistant to bariatric surgery.

Commissioning guidance for weight assessment and management in adults and children with severe complex obesity

The challenge of managing the epidemic of patients with severe and complex obesity disease in secondary care is largely unmet. In England, the National Institute of Health and Care Excellence and the National Health Service England have published guidance on the provision of specialist (non-surgical) weight management services. We have undertaken a systematic review of 'what evidence exists for what should happen in/commissioning of: primary or secondary care weight assessment and management clinics in patients needing specialist care for severe and complex obesity?' using an accredited methodology to produce a model for organization of multidisciplinary team clinics that could be developed in every healthcare system, as an update to a previous review. Additions to the previous guidance were multidisciplinary team pathways for children/adolescent patients and their transition to adult care, anaesthetic assessment and recommendations for ongoing shared care with general practitioners, as a chronic disease management pathway.

Glucose effectiveness, but not insulin sensitivity, is improved after short-term interval training in individuals with type 2 diabetes mellitus: a controlled, randomised, crossover trial

AIMS/HYPOTHESIS

The role of glucose effectiveness (S _G) in training-induced improvements in glucose metabolism in individuals with type 2 diabetes is unknown. The objectives and primary outcomes of this study were: (1) to assess the efficacy of interval walking training (IWT) and continuous walking training (CWT) on S _G and insulin sensitivity (S _I) in individuals with type 2 diabetes; and (2) to assess the association of changes in S _G and S _I with changes in glycaemic control.

METHODS

Fourteen participants with type 2 diabetes underwent three trials (IWT, CWT and no training) in a crossover study. Exclusion criteria were exogenous insulin treatment, smoking, pregnancy, contraindications to structured physical activity and participation in recurrent training (>90 min/week). The trials were performed in a randomised order (computerised-generated randomisation). IWT and CWT consisted of ten supervised treadmill walking sessions, each lasting 60 min, over 2 weeks. IWT was performed as repeated cycles of 3 min slow walking and 3 min fast walking (aiming for 54% and 89% of [Formula: see text], respectively, which was measured during the last minute of each interval), and CWT was performed aiming for a moderate walking speed (73% of [Formula: see text]). A two-step (pancreatic and hyperinsulinaemic) hyperglycaemic clamp was implemented before and after each trial. All data were collected in a hospitalised setting. Neither participants nor assessors were blinded to the trial interventions.

RESULTS

Thirteen individuals completed all procedures and were included in the analyses. IWT improved S _G (mean ± SEM: 0.6 ± 0.1 mg kg^-1 min^-1, p < 0.05) but not S _I (p > 0.05), whereas CWT matched for energy expenditure and time duration improved neither S _G nor S _I (both p > 0.05). Changes in S _G, but not in S _I, were associated with changes in mean (β = -0.62 ± 0.23, r ² = 0.17, p < 0.01) and maximum (β = -1.18 ± 0.52, r ² = 0.12, p < 0.05) glucose levels during 24 h continuous glucose monitoring.

CONCLUSIONS/INTERPRETATION

Two weeks of IWT, but not CWT, improves S _G but not S _I in individuals with type 2 diabetes. Moreover, changes in S _G are associated with changes in glycaemic control. Therefore, increased S _G is likely an important mechanism by which training improves glycaemic control in individuals with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02320526 FUNDING: CFAS is supported by a grant from TrygFonden. During the study period, the Centre of Inflammation and Metabolism (CIM) was supported by a grant from the Danish National Research Foundation (DNRF55). The study was further supported by grants from Diabetesforeningen, Augustinusfonden and Krista og Viggo Petersens Fond. CIM/CFAS is a member of DD2-the Danish Center for Strategic Research in Type 2 Diabetes (the Danish Council for Strategic Research, grant no. 09-067009 and 09-075724).

Does physical activity protect against the development of gastroesophageal reflux disease, Barrett's esophagus, and esophageal adenocarcinoma? A review of the literature with a meta-analysis

Physical activity affects the functioning of the gastrointestinal system through both local and systemic effects and may play an important role in reducing the risk of esophageal adenocarcinoma. This review assesses the biological mechanisms and epidemiological evidence for the relationship between physical activity and the development of esophageal adenocarcinoma and its precursor diseases: gastroesophageal reflux disease (GORD) and Barrett's esophagus. A search of PubMed, Medline, Embase, and CINAHL was conducted from their inceptions to 25th March 2017 for analytical studies that examined associations between recreational and/or occupational levels of physical activity and the risk of GORD, Barrett's esophagus, and esophageal adenocarcinoma. Where appropriate, a meta-analysis of effects was undertaken. Seven studies were included (2 cohort, 5 case control). For GORD, there were three case-control studies with 10 200 cases among 78 034 participants, with a pooled estimated OR of 0.67 (95% CI 0.57-0.78) for high versus low levels of recreational physical activity. In Barrett's esophagus, there was a single case-control study, which reported no association, OR 1.19 (95% CI 0.82-1.73). For esophageal adenocarcinoma, there were three studies (two prospective cohort, one case control) with 666 cases among 910 376 participants. The largest cohort study reported an inverse association for high versus low levels of recreational physical activity, RR 0.68, 95% CI 0.48-0.96. The remaining two studies reported no associations with either occupational or combined recreational and occupational activity. Heterogeneity in the measurement of exposure (recreational, occupational, and both) made a pooled estimate for esophageal adenocarcinoma inappropriate. Although limited, there is some evidence that higher levels of recreational physical activity may reduce the risk of both GORD and esophageal adenocarcinoma, but further large cohort studies examining the type, intensity and duration of activities that may be beneficial are needed.

Factors associated with long-term weight-loss maintenance following bariatric surgery in adolescents with severe obesity

BACKGROUND/OBJECTIVES

Bariatric surgery produces robust weight loss, however, factors associated with long-term weight-loss maintenance among adolescents undergoing Roux-en-Y gastric bypass surgery are unknown.

SUBJECTS/METHODS

Fifty adolescents (mean±s.d. age and body mass index (BMI)=17.1±1.7 years and 59±11 kg m^-2) underwent Roux-en-Y gastric bypass surgery, had follow-up visits at 1 year and at a visit between 5 and 12 years following surgery (Follow-up of Adolescent Bariatric Surgery at 5 Plus years (FABS-5+) visit; mean±s.d. 8.1±1.6 years). A non-surgical comparison group (n=30; mean±s.d. age and BMI=15.3±1.7 years and BMI=52±8 kg m^-2) was recruited to compare weight trajectories over time. Questionnaires (health-related and eating behaviors, health responsibility, impact of weight on quality of life (QOL), international physical activity questionnaire and dietary habits via surgery guidelines) were administered at the FABS-5+ visit. Post hoc, participants were split into two groups: long-term weight-loss maintainers (n=23; baseline BMI=58.2 kg m^-2; 1-year BMI=35.8 kg m^-2; FABS-5+ BMI=34.9 kg m^-2) and re-gainers (n=27; baseline BMI=59.8 kg m^-2; 1-year BMI=36.8 kg m^-2; FABS-5+ BMI=48.0 kg m^-2) to compare factors which might contribute to differences. Data were analyzed using generalized estimating equations adjusted for age, sex, baseline BMI, baseline diabetes status and length of follow-up.

RESULTS

The BMI of the surgical group declined from baseline to 1 year (-38.5±6.9%), which, despite some regain, was largely maintained until FABS-5+ (-29.6±13.9% change). The BMI of the comparison group increased from baseline to the FABS-5+ visit (+10.3±20.6%). When the surgical group was split into maintainers and re-gainers, no differences in weight-related and eating behaviors, health responsibility, physical activity/inactivity, or dietary habits were observed between groups. However, at FABS-5+, maintainers had greater overall QOL scores than re-gainers (87.5±10.5 vs 65.4±20.2, P<0.001) and in each QOL sub-domain (P<0.01 all).

CONCLUSIONS

Long-term weight outcomes for those who underwent weight-loss surgery were superior to those who did not undergo surgical treatment. While no behavioral factors were identified as predictors of success in long-term weight-loss maintenance, greater QOL was strongly associated with maintenance of weight loss among adolescents who underwent Roux-en-Y gastric bypass surgery surgery.

Roux-en-Y gastric bypass surgery enhances contraction-mediated glucose metabolism in primary human myotubes

Contractile activity (e.g., exercise) evokes numerous metabolic adaptations in human skeletal muscle, including enhanced insulin action and substrate oxidation. However, there is intersubject variation in the physiological responses to exercise, which may be linked with factors such as the degree of obesity. Roux-en-Y gastric bypass (RYGB) surgery reduces body mass in severely obese (body mass index ≥ 40 kg/m²) individuals; however, it is uncertain whether RYGB can potentiate responses to contractile activity in this potentially exercise-resistant population. To examine possible interactions between RYGB and contractile activity, muscle biopsies were obtained from severely obese patients before and after RYGB, differentiated into myotubes, and electrically stimulated, after which changes in insulin action and glucose oxidation were determined. Before RYGB, myotubes were unresponsive to electrical stimulation, as indicated by no changes in insulin-stimulated glycogen synthesis and basal glucose oxidation. However, myotubes from the same patients at 1 mo after RYGB increased insulin-stimulated glycogen synthesis and basal glucose oxidation when subjected to contraction. While unresponsive before surgery, contraction improved insulin-stimulated phosphorylation of AS160 (Thr642, Ser704) after RYGB. These data suggest that RYGB surgery may enhance the ability of skeletal muscle from severely obese individuals to respond to contractile activity.

Randomized trial reveals that physical activity and energy expenditure are associated with weight and body composition after RYGB

OBJECTIVE

This study investigated the associations of both physical activity time (PA) and energy expenditure (EE) with weight and fat mass (FM) loss in patients following Roux-en-Y gastric bypass (RYGB) surgery.

METHODS

Ninety-six nondiabetic patients were included in this analysis. Post-RYGB patients were randomized in one of two treatments: A 6-month exercise training program (RYBG+EX) or lifestyle educational classes (RYGB). Body composition was assessed by dual-energy X-ray absorptiometry and computed tomography. Components of PA and EE were quantified by a multisensory device. Dose-response relationships of both PA and EE with weight loss and body composition were explored according to quartiles of change in steps per day.

RESULTS

Patients in the highest quartiles of steps per day change lost more FM (3rd = -19.5 kg and 4th = -22.7 kg, P < 0.05) and abdominal adipose tissue (4th = -313 cm² , P < 0.05), maintained skeletal muscle mass (3rd = -3.1 cm² and 4th = -4.5 cm² , P <  0.05), and had greater reductions in resting metabolic rate. Decreases in sedentary EE and increases in light EE and age were significant predictors of both Δweight and ΔFM (R²  = 73.8% and R²  = 70.6%, respectively).

CONCLUSIONS

Nondiabetic patients who perform higher, yet still modest, amounts of PA following RYGB have greater energy deficits and lose more weight and FM, while maintaining higher skeletal muscle mass.

Comparing minimally supervised home-based and closely supervised gym-based exercise programs in weight reduction and insulin resistance after bariatric surgery: A randomized clinical trial

Background: Effectiveness of various exercise protocols in weight reduction after bariatric surgery has not been sufficiently explored in the literature. Thus, in the present study, we aimed at comparing the effect of minimally supervised home-based and closely supervised gym-based exercise programs on weight reduction and insulin resistance after bariatric surgery.

Methods: Females undergoing gastric bypass surgery were invited to participate in an exercise program and were randomly allocated into 2 groups using a random number generator in Excel. They were either offered a minimally supervised home-based (MSHB) or closely supervised gym-based (CSGB) exercise program. The CSGB protocol constitutes 2 weekly training sessions under ACSM guidelines. In the MSHB protocol, the participants received a notebook containing a list of recommended aerobic and resistance exercises, a log to record their activity, and a schedule of follow-up phone calls and clinic visits. Both groups received a pedometer. We measured their weight, BMI, lipid profile, FBS, and insulin level at baseline and at 20 weeks after the exercises, the results of which were compared using t test or Mann-Whitney U test at the end of the study. All the processes were observed by 1 senior resident in sport medicine.

Results: A total of 80 patients were recruited who were all able to complete our study (MSHB= 38 and CSGB= 42). The baseline comparison revealed that the 2 groups were similar. The mean change (reduction) in BMI was slightly better in CSGB (8.61 95% CI 7.76–9.45) compared with the MSHB (5.18 95% CI 3.91–6.46); p< 0.01. However, the 2 groups did not have a statistically significant difference in the amount of change in the other factors including FBS and Homa.ir.

Conclusion: As we expected a non-inferiority result, our results showed that both MSHB and CSGB exercise methods are somewhat equally effective in improving lipid profile and insulin resistance in the 2 groups, but a slightly better effect on BMI was observed in CSGB group. With considerably lower costs of minimally supervised home- based exercise programs, both methods should be considered when there is lack of adequate funding.

Metabolic Flexibility in Health and Disease

Metabolic flexibility is the ability to respond or adapt to conditional changes in metabolic demand. This broad concept has been propagated to explain insulin resistance and mechanisms governing fuel selection between glucose and fatty acids, highlighting the metabolic inflexibility of obesity and type 2 diabetes. In parallel, contemporary exercise physiology research has helped to identify potential mechanisms underlying altered fuel metabolism in obesity and diabetes. Advances in "omics" technologies have further stimulated additional basic and clinical-translational research to further interrogate mechanisms for improved metabolic flexibility in skeletal muscle and adipose tissue with the goal of preventing and treating metabolic disease.

Gastric bypass surgery with exercise alters plasma microRNAs that predict improvements in cardiometabolic risk

BACKGROUND/OBJECTIVES

Roux-en-Y gastric bypass (RYGB) surgery improves insulin sensitivity (S_I) and β-cell function in obese non-diabetic subjects. Exercise also improves S_I and may be an effective adjunct therapy to RYGB surgery. However, the mechanisms by which exercise or weight loss improve peripheral S_I after RYGB surgery are unclear. We hypothesized that microRNAs (miRNAs) mediate at least some of the regulatory processes driving such mechanisms. Consequently, this work aimed at profiling plasma miRNAs in participants of the Physical Activity Following Surgery Induced Weight Loss study (clinicaltrials.gov identifier: NCT00692367), to assess whether miRNA levels track with improvements in S_I and cardiometabolic risk factors.

SUBJECTS/METHODS

Ninety-four miRNAs implicated in metabolism were profiled in plasma samples from 22 severely obese subjects who were recruited 1-3 months after RYGB surgery and followed for 6 months of RYGB surgery-induced weight loss, with (exercise program (EX), N=11) or without (CON, N=11) an exercise training intervention. The subjects were selected, considering a priori sample size calculations, among the participants in the parent study. Mixed-effect modeling for repeated measures and partial correlation analysis was implemented in the R environment for statistical analysis.

RESULTS

Mirroring results in the parent trial, both groups experienced significant weight loss and improvements in cardiometabolic risk. In the CON group, weight loss significantly altered the pattern of circulating miR-7, miR-15a, miR-34a, miR-106a, miR-122 and miR-221. In the EX group, a distinct miRNA signature was altered: miR-15a, miR-34a, miR-122, miR-135b, miR-144, miR-149 and miR-206. Several miRNAs were significantly associated with improvements in acute insulin response, S_I, and other cardiometabolic risk factors.

CONCLUSIONS

These findings present novel insights into the RYGB surgery-induced molecular changes and the effects of mild exercise to facilitate and/or maintain the benefits of a 'comprehensive' weight-loss intervention with concomitant improvements in cardiometabolic functions. Notably, we show a predictive value for miR-7, miR-15a, miR-106b and miR-135b.

The effects of supervised exercise training 12-24 months after bariatric surgery on physical function and body composition: a randomised controlled trial

BACKGROUND

Bariatric surgery is effective for the treatment of stage II and III obesity and its related diseases, although increasing evidence is showing weight regain ~12-24 months postsurgery. Weight regain increases the risk of physical function decline, which negatively affects an individual's ability to undertake activities of daily living. The study assessed the effects of a 12-week supervised exercise intervention on physical function and body composition in patients between 12 and 24 months post bariatric surgery.

METHODS

Twenty-four inactive adult bariatric surgery patients whose body mass index remained ⩾30 kg m² 12 to 24 months post surgery were randomised to an exercise intervention (n=12) or control group (n=12). Supervised exercise consisted of three 60-min gym sessions per week of moderate intensity aerobic and resistance training for 12 weeks. Control participants received usual care. The incremental shuttle walk test (ISWT) was used to assess functional walking performance after the 12-week exercise intervention, and at 24 weeks follow-up. Measures of anthropometric, physical activity, cardiovascular and psychological outcomes were also examined. Using an intention-to-treat protocol, independent t-tests were used to compare outcome measures between groups.

RESULTS

Significant improvements in the exercise group were observed for the ISWT, body composition, physical function, cardiovascular and self-efficacy measures from baseline to 12 weeks. A large baseline to 12-week change was observed for the ISWT (exercise: 325.00±117.28 m; control: 355.00±80.62 m, P<0.001). The exercise group at 24 weeks recorded an overall mean improvement of 143.3±86.6 m and the control group recorded a reduction of -32.50±75.93 m. Findings show a 5.6 kg difference between groups in body mass change from baseline to 24 weeks favouring the exercise group.

CONCLUSIONS

A 12-week supervised exercise intervention led to significant improvements in body mass and functional walking ability post intervention, with further improvements at the 24-week follow-up.

Intervention-related increases in preoperative physical activity are maintained 6-months after Bariatric surgery: results from the bari-active trial

Higher preoperative physical activity (PA) strongly predicts higher post-operative PA in bariatric surgery (BS) patients, providing rationale for preoperative PA interventions (PAIs). However, whether PAI-related increases can be maintained post-operatively has not been examined. This study compared PA changes across pre- (baseline, post-intervention) and post-operative (6-month follow up) periods in participants randomized to 6 weeks of preoperative PAI or standard care control (SC). Of 75 participants initially randomized, 36 (PAI n=22; SC n=14) underwent BS. Changes in daily bout-related (⩾10-min bouts) moderate-to-vigorous PA (MVPA) and steps were assessed via the SenseWear Armband monitor. PAI received weekly counseling to increase walking exercise. Retention (86%) at post-operative follow up was similar between groups. Intent-to-treat analyses showed that PAI vs SC had greater increases across time (baseline, post-intervention, follow up) in bout-related MVPA minutes/day (4.3±5.1, 26.3±21.3, 28.7±26.3 vs 10.4±22.9, 11.4±16.0, 18.5±28.2; P=0.013) and steps/day (5163±2901, 7950±3286, 7870±3936 vs 5163±2901, 5601±3368, 5087±2603; P<0.001). PAI differed from SC on bout-related MVPA at post-intervention (P=0.016; d=0.91), but not follow up (P=0.15; d=0.41), and steps at post-intervention (P=0.031; d=0.78) and follow up (P=0.024; d=0.84). PAI participants maintained preoperative PA increases post-operatively. Findings support preoperative PAIs and research to test whether PA changes can be sustained and influence surgical outcomes beyond the initial post-operative period.

Type 2 Diabetes Treatment in the Patient with Obesity

Lifestyle modification is the cornerstone treatment of type 2 diabetes in the obese patient, and is highly effective at promoting glucose regulation. However, many individuals struggle over time to maintain optimal glycemic control and/or body weight with lifestyle modification. Therefore, additional therapeutic approaches are needed. Pharmacologic interventions have shown promising results for obesity-related diabetes complications. Not surprisingly though lifestyle modification and pharmacology may become ineffective for treating diabetes over time. Bariatric surgery is considered by some, but not all, to be the most effective and durable treatment for combating obesity. In fact many patients with type 2 diabetes have normalized glucose concentrations within days postoperation. Taken together, treatment of obesity in the patient with type 2 diabetes requires a multi-faceted approach.

Relationship among physical activity, sedentary behaviors, and cardiometabolic risk factors during gastric bypass surgery-induced weight loss

BACKGROUND

The impact of daily physical activity (PA) on the cardiometabolic risk of bariatric surgery patients is not known.

OBJECTIVE

We examined the influence of physical activity and sedentary behavior on modifying cardiometabolic risk after Roux-en-Y gastric bypass (RYGB) surgery.

SETTING

University of Pittsburgh Medical Center and East Carolina University bariatric surgery centers.

METHODS

Data from 43 women and 7 men who completed testing at 1-3 months after RYGB surgery and again at 9 months postsurgery were analyzed. Outcomes measured included PA level (min/d), steps/d, sedentary time, and body composition. Insulin sensitivity was determined with an intravenous glucose tolerance test. Weight and blood lipid profiles also were obtained.

RESULTS

Patients reduced body mass index by a mean of -8.0±3.4 kg/m² (P<.001), increased moderate-to-vigorous PA by 17.0±47.0 min/d (P = .014), and decreased sedentary time (-47.9±101.0 min/d, P = .002). However, 24% of patients decreased overall PA (P<.001), and 39% increased sedentary behavior (P<.001). Changes in overall PA (rho = -.33, P = .006) and steps/d (rho = -.31, P = .0106) were related to weight loss. Insulin sensitivity was associated with light PA before (rho = .37, P<.001) and after (rho = .37, P = .015) intervention. Increasing overall PA also was related to higher levels of high-density lipoprotein cholesterol (rho = .33, P<.01). Decreasing sedentary time was related to decreased fat mass (rho = .35, P = .012) but not to other cardiometabolic risk factors.

CONCLUSIONS

The majority of patients increased PA (76%) and decreased sedentary time (61%) after RYGB surgery, but the amount of PA and sedentary time varied substantially. Higher PA, even at low intensity levels, was related to beneficial outcomes in body composition, insulin sensitivity, and high-density lipoprotein cholesterol.

Exercise resistance across the prediabetes phenotypes: Impact on insulin sensitivity and substrate metabolism

Prediabetes is a heterogeneous term that encompasses different origins of insulin resistance and insulin secretion that contribute to distinct patterns of hyperglycemia. In fact, prediabetes is an umbrella term that characterizes individuals at high risk for developing type 2 diabetes (T2D) and/or cardiovascular disease (CVD). Based on current definitions there are at least 3 distinct phenotypes of prediabetes: impaired fasting glucose (IFG), impaired glucose tolerant (IGT), or the combination of both (IFG + IGT). Each phenotype is clinically relevant as they are uniquely recognized as having different levels of risk for progressing to T2D and CVD. Herein, we discuss the underlying pathophysiology that characterizes IFG, IGT and the combination, as well as examine how some of these phenotypes appear resistant to traditional exercise interventions. We propose that substrate metabolism differences between the prediabetes phenotypes may be a unifying mechanism that explains the inter-subject variation in response to exercise seen across obese, metabolic syndrome, pre-diabetic and T2D patients in the current literature. Ultimately, a better understanding of the pathophysiologic mechanisms that govern disturbances responsible for fasting vs. postprandial hyperglycemia and the combination of both is important for designing optimal and personalized exercise treatment strategies that treat and prevent hyperglycemia and CVD risk.

A role for exercise after bariatric surgery?

Obesity predisposes an individual to develop numerous comorbidities, including type 2 diabetes, and represents a major healthcare issue in many countries worldwide. Bariatric surgery can be an effective treatment option, resulting in profound weight loss and improvements in metabolic health; however, not all patients achieve similar weight loss or metabolic improvements. Exercise is an excellent way to improve health, with well-characterized physiological and psychological benefits. In the present paper we review the evidence to determine whether there may be a role for exercise as a complementary adjunct therapy to bariatric surgery. Objectively measured physical activity data indicate that most patients who undergo bariatric surgery do not exercise enough to reap the health benefits of exercise. While there is a dearth of data on the effects of exercise on weight loss and weight loss maintenance after surgery, evidence from studies of caloric restriction and exercise suggest that similar adjunctive benefits may be extended to patients who perform exercise after bariatric surgery. Recent evidence from exercise interventions after bariatric surgery suggests that exercise may provide further improvements in metabolic health compared with surgery-induced weight loss alone. Additional randomized controlled exercise trials are now needed as the next step to more clearly define the potential for exercise to provide additional health benefits after bariatric surgery. This valuable evidence will inform clinical practice regarding much-needed guidelines for exercise after bariatric surgery.

Dose response of exercise training following roux-en-Y gastric bypass surgery: A randomized trial

OBJECTIVE

Roux-en-Y gastric bypass (RYGB) surgery can cause profound weight loss and improve overall cardiometabolic risk factors. Exercise (EX) training following RYGB can provide additional improvements in insulin sensitivity (SI ) and cardiorespiratory fitness. However, it remains unknown whether a specific amount of EX post-RYGB is required to achieve additional benefits.

METHODS

We performed a post hoc analysis of participants who were randomized into either a 6-month structured EX program or a health education control (CON). The EX group (n = 56) was divided into tertiles according to the amount of weekly exercise performed, compared with CON (n = 42): low-EX = 54 ± 8; middle-EX = 129 ± 4; and high-EX = 286 ± 40 min per week.

RESULTS

The high-EX lost a significantly greater amount of body weight, total fat mass, and abdominal deep subcutaneous abdominal fat compared with CON (P < 0.005). SI improved to a greater extent in both the middle-EX and high-EX compared with CON (P < 0.04). Physical fitness (VO2 max) significantly improved in the high-EX (9.3% ± 4.2%) compared with CON (-6.0 ± 2.4%) (P < 0.001). Skeletal muscle mitochondrial State 4 (P < 0.002) and 3 (P < 0.04) respiration was significantly higher in the high-EX compared with CON.

CONCLUSIONS

A modest volume of structured exercise provides additional improvements in insulin sensitivity following RYGB, but higher volumes of exercise are required to induce additional weight loss, changes in body composition, and improvements in cardiorespiratory fitness and skeletal muscle mitochondrial capacity.

Exercise and Weight Loss Improve Muscle Mitochondrial Respiration, Lipid Partitioning, and Insulin Sensitivity After Gastric Bypass Surgery

Both Roux-en-Y gastric bypass (RYGB) surgery and exercise can improve insulin sensitivity in individuals with severe obesity. However, the impact of RYGB with or without exercise on skeletal muscle mitochondria, intramyocellular lipids, and insulin sensitivity index (SI) is unknown. We conducted a randomized exercise trial in patients (n = 101) who underwent RYGB surgery and completed either a 6-month moderate exercise (EX) or a health education control (CON) intervention. SI was determined by intravenous glucose tolerance test. Mitochondrial respiration and intramyocellular triglyceride, sphingolipid, and diacylglycerol content were measured in vastus lateralis biopsy specimens. We found that EX provided additional improvements in SI and that only EX improved cardiorespiratory fitness, mitochondrial respiration and enzyme activities, and cardiolipin profile with no change in mitochondrial content. Muscle triglycerides were reduced in type I fibers in CON, and sphingolipids decreased in both groups, with EX showing a further reduction in a number of ceramide species. In conclusion, exercise superimposed on bariatric surgery-induced weight loss enhances mitochondrial respiration, induces cardiolipin remodeling, reduces specific sphingolipids, and provides additional improvements in insulin sensitivity.

Measurement and Intervention on Physical Activity and Sedentary Behaviours in Bariatric Surgery Patients: Emphasis on Mobile Technology

Physical activity (PA) and sedentary behaviours (SB-i.e. activities involving low-energy expenditure and a sitting/reclining posture) may each have significant implications for weight loss and other bariatric surgery outcomes. While early studies suggested that patients typically comply with clinical recommendations to adopt habitual PA, these data were based on retrospective questionnaires. Conversely, recent studies incorporating mobile health (mHealth) technologies (e.g. objective monitors), which assess PA and SB in real time and in the natural environment, show that most patients are inactive and highly sedentary pre-operatively and only make modest changes in these behaviours postoperatively. In addition to using mHealth technologies for obtaining accurate and detailed information on PA and SB, they are increasingly being employed to intervene on patients' PA and SB and/or evaluate intervention outcomes. Researchers and clinicians are encouraged to consider the benefits of using mHealth technology when studying and treating PA and SB in bariatric surgery patients.

Bariatric and metabolic surgery: a shift in eligibility and success criteria

The obesity epidemic, combined with the lack of available and effective treatments for morbid obesity, is a scientific and public health priority. Worldwide, bariatric and metabolic surgeries are increasingly being performed to effectively aid weight loss in patients with severe obesity, as well as because of the favourable metabolic effects of the procedures. The positive effects of bariatric surgery, especially with respect to improvements in type 2 diabetes mellitus, have expanded the eligibility criteria for metabolic surgery to patients with diabetes mellitus and a BMI of 30-35 kg/m(2). However, the limitations of BMI, both in the diagnosis and follow-up of patients, need to be considered, particularly for determining the actual adiposity and fat distribution of the patients following weight loss. Understanding the characteristics shared by bariatric and metabolic surgeries, as well as their differential aspects and outcomes, is required to enhance patient benefits and operative achievements. For a holistic approach that focuses on the multifactorial effects of bariatric and metabolic surgery to be possible, a paradigm shift that goes beyond the pure semantics is needed. Such a shift could lead to profound clinical implications for eligibility criteria and the definition of success of the surgical approach.

Bariatric surgery, lipoprotein metabolism and cardiovascular risk

PURPOSE OF REVIEW

To summarize recent epidemiological, preclinical and clinical studies on the effects of Roux-en-Y-gastric bypass (RYGBP) surgery on cardiovascular risk factors and the underlying mechanisms.

RECENT FINDINGS

Although RYGBP has mechanical effects on the gastrointestinal tract, the reduced gastric pouch and intestinal calorie absorption cannot fully explain the metabolic improvements.

SUMMARY

Obesity predisposes to cardiovascular risk factors such as dyslipidemia, type 2 diabetes, nonalcoholic fatty liver disease and hypertension. In contrast to the limited success of pharmacological and lifestyle interventions, RYGBP induces sustained weight loss, metabolic improvements and decreases morbidity/mortality. In line, RYGBP reduces cardiovascular risk factors. Although the mechanisms are not entirely understood, RYGBP induces complex changes in the gut affecting other organs through endocrine and metabolic signals from the intestine to all key metabolic organs, which can link RYGBP and decreased cardiovascular risk. Here, we discuss the roles of changes in lipid absorption and metabolism, bile acid metabolism, gut hormones and the microbiote as potential mechanisms in the decreased cardiovascular risk and metabolic improvement after RYGBP.

Feasibility and Impact of a Combined Supervised Exercise and Nutritional-Behavioral Intervention following Bariatric Surgery: A Pilot Study

BACKGROUND

Lifestyle intervention programs after bariatric surgery have been suggested to maximise health outcomes. This pilot study aimed to investigate the feasibility and impact of an 8-week combined supervised exercise with nutritional-behavioral intervention following Roux-en-Y gastric bypass and sleeve gastrectomy.

METHODS

Eight female patients (44 ± 8 years old, BMI = 38.5 ± 7.2 kg m(-2)) completed the program. Before and after intervention, anthropometric measures, six-minute walk test (6MWT), physical activity level, eating behavior, and quality of life (QoL) were assessed. Percentage weight loss (%WL) outcomes were compared with a historical matched control group.

RESULTS

The program significantly improved functional capacity (mean increment in 6MWT was 127 ± 107 meters, p = 0.043), increased strenuous intensity exercise (44 ± 49 min/week, p = 0.043), increased consumption of fruits and vegetables (p = 0.034), reduced consumption of ready meals (p = 0.034), and improved "Change in Health" in QoL domain (p = 0.039). The intervention group exhibited greater %WL in the 3-12-month postsurgery period compared to historical controls, 12.2 ± 7.5% versus 5.1 ± 5.4%, respectively (p = 0.027).

CONCLUSIONS

Lifestyle intervention program following bariatric surgery is feasible and resulted in several beneficial outcomes. A large randomised control trial is now warranted.