The Effect of an Exercise Intervention Program on Bone Health After Bariatric Surgery: A Randomized Controlled Trial

Exercise interventions following bariatric surgery are poorly reported: A systematic review and a call for action

OBJECTIVES

This study assessed the transparency and replicability of exercise-based interventions following bariatric surgery by evaluating the content reporting of exercise-based clinical trials.

DESIGN

The study design of the present article is a systematic review.

DATA SOURCES

PubMed, Scopus, Web of Sciences, PsycINFO, and Cochrane were searched from their inception to May 2023.

ELIGIBILITY CRITERIA

Eligible studies were clinical trials including exercise interventions in participants following bariatric surgery. There were 28 unique exercise interventions. Two independent reviewers applied the exercise prescription components of Frequency, Intensity, Time, and Type (FITT; four items) and the Consensus on Exercise Reporting Template (CERT; 19 items). Exercise interventions were organized into four major exercise components: aerobic training, resistance training, concurrent training, and "others."

RESULTS

The FITT assessment revealed that 53% of the trials did not report the training intensity, whereas 25% did not indicate the duration of the major exercise component within the training session. The mean CERT score was 5 out of a possible score of 19. No studies reached CERT score >10, while 13 out of the total 19 CERT items were not adequately reported by ≥75% of the studies.

CONCLUSION

This study highlights that the exercise interventions following bariatric surgery are poorly reported, non-transparent, and generally not replicable. This precludes understanding the dose-response association of exercise and health-related effects and requires action to improve this scientific field.

Intersession reliability of lower limb muscle strength assessments in adults with obesity eligible for bariatric surgery

BACKGROUND

The aim of this study was to examine the test-retest reliability in lower limb muscle strength and rate of torque development (RTD) using isokinetic dynamometry in adults with obesity, with a body mass index (BMI) ≥ 35 kg/m2.

METHOD

Thirty-two adults with a BMI of 43.8 ± 6.6 kg/m2 eligible for bariatric surgery were enroled in the study. Isokinetic and isometric knee extensor (KE) and flexor (KF) strength were assessed in an isokinetic dynamometer (Biodex 4) during three test sessions separated by 3-7 days.

RESULTS

There were no statistical differences in peak KE and KF torque for any test modalities between sessions. Intraclass correlation (ICC) was 0.91-0.94 between sessions 1 and 2 and 0.94-0.97 between sessions 2 and 3. Standard error of measurement (SEM%) and coefficient of variation (CV) ranged across test sessions from 4.3% to 7.3%. KE RTD showed high test-retest reliability following familiarization, with ICC, CV and SEM% values ranging from 0.84 to 0.90, 13.3%-20.3% and 14.6%-24.9%, respectively.

CONCLUSION

Maximal lower limb muscle strength measured by isokinetic dynamometry showed excellent test-retest reliability manifested by small measurement errors and low CV. Reliability was slightly improved by including a familiarization session. KE RTD but not KF RTD demonstrated high test-retest reliability following familiarization. The present data indicate that isokinetic dynamometry can be used to detect even small changes in lower limb muscle strength in adults with obesity.

Bone Health After Exercise Alone, GLP-1 Receptor Agonist Treatment, or Combination Treatment: A Secondary Analysis of a Randomized Clinical Trial

Importance

A major concern with weight loss is concomitant bone loss. Exercise and glucagon-like peptide-1 receptor agonists (GLP-1RAs) represent weight loss strategies that may protect bone mass despite weight loss.

Objective

To investigate bone health at clinically relevant sites (hip, spine, and forearm) after diet-induced weight loss followed by a 1-year intervention with exercise, liraglutide, or both combined.

Design, Setting, and Participants

This study was a predefined secondary analysis of a randomized clinical trial conducted between August 2016 and November 2019 at the University of Copenhagen and Hvidovre Hospital in Denmark. Eligible participants included adults aged 18 to 65 years with obesity (body mass index of 32-43) and without diabetes. Data analysis was conducted from March to April 2023, with additional analysis in February 2024 during revision.

Interventions

After an 8-week low-calorie diet (800 kcal/day), participants were randomized to 1 of 4 groups for 52 weeks: a moderate- to vigorous-intensity exercise program (exercise alone), 3.0 mg daily of the GLP-1 RA liraglutide (liraglutide alone), the combination, or placebo.

Main Outcomes and Measures

The primary outcome was change in site-specific bone mineral density (BMD) at the hip, lumbar spine, and distal forearm from before the low-calorie diet to the end of treatment, measured by dual-energy x-ray absorptiometry in the intention-to-treat population.

Results

In total, 195 participants (mean [SD] age, 42.84 [11.87] years; 124 female [64%] and 71 male [36%]; mean [SD] BMI, 37.00 [2.92]) were randomized, with 48 participants in the exercise group, 49 participants in the liraglutide group, 49 participants in the combination group, and 49 participants in the placebo group. The total estimated mean change in weight losses during the study was 7.03 kg (95% CI, 4.25-9.80 kg) in the placebo group, 11.19 kg (95% CI, 8.40-13.99 kg) in the exercise group, 13.74 kg (95% CI, 11.04-16.44 kg) in the liraglutide group, and 16.88 kg (95% CI, 14.23-19.54 kg) in the combination group. In the combination group, BMD was unchanged compared with the placebo group at the hip (mean change, -0.006 g/cm2; 95% CI, -0.017 to 0.004 g/cm2; P = .24) and lumbar spine (-0.010 g/cm2; 95% CI, -0.025 to 0.005 g/cm2; P = .20). Compared with the exercise group, BMD decreased for the liraglutide group at the hip (mean change, -0.013 g/cm2; 95% CI, -0.024 to -0.001 g/cm2; P = .03) and spine (mean change, -0.016 g/cm2; 95% CI, -0.032 to -0.001 g/cm2; P = .04).

Conclusions and Relevance

In this randomized clinical trial, the combination of exercise and GLP-1RA (liraglutide) was the most effective weight loss strategy while preserving bone health. Liraglutide treatment alone reduced BMD at clinically relevant sites more than exercise alone despite similar weight loss.

Trial Registration

EudraCT: 2015-005585-32.

The effect of physical activity on vitamin D: A systematic review and meta-analysis of intervention studies in humans

Objectives

Cross-sectional studies demonstrate a positive association between higher physical activity and serum 25-hydroxyvitamin D (25(OH)D) concentration. However, whether this association is causal is unclear. We conducted a systematic review to identify intervention studies that examined the effect of physical activity on serum 25(OH)D concentration in humans.

Study design

Systematic review and meta-analysis.

Methods

We searched PubMed, Scopus and Web of Science to identify full-text peer-reviewed articles published in English from inception until January 2023. Eligible studies were randomised controlled trials or quasi-experimental studies. We used random effects meta-analysis to calculate the weighted mean difference (WMD) in the change in 25(OH)D concentration between physical activity and control groups. We used the revised Cochrane risk-of-bias tool for randomized trials (RoB 2) to assess the methodological quality of included studies.

Results

We included 32 articles in the systematic review and 24 in the meta-analysis. The intervention varied from resistance and weight-bearing exercises (n = 13) to aerobic exercises (n = 10), moderate and moderate-to-vigorous exercises (n = 5), aquatic exercise (n = 2), and multicomponent traditional exercises (n = 2) (Tai Chi and Yijinjing). The WMD in 25(OH)D in the physical activity and control groups was 9.51 and 4.87, respectively (between-group mean difference 4.64, p = 0.002). However, the difference was only evident in studies that implemented the intervention outdoors (n = 3; between-group mean difference 17.33, p < 0.0001); when the intervention was indoors there was no significant effect of physical activity on 25(OH)D (n = 16; between-group mean difference 1.80, p = 0.113).

Conclusions

This meta-analysis of physical activity interventions in humans showed that physical activity does not lead to increased 25(OH)D independently of time outdoors. However, most studies were under-powered, in many the exercise was low intensity, and vitamin D was not the primary outcome.

Impact of a Multicomponent Exercise Training Program on Muscle Strength After Bariatric Surgery: A Randomized Controlled Trial

PURPOSE

This study examined the benefits of an 11-months multicomponent exercise program (MEP) on muscular strength (MS) after bariatric surgery.

METHODS

Of the 84 randomized patients, 41 participants from the exercise group (EG) and 20 participants from the control group (CG) were included in the analysis. The EG received supervised MEP for 11 months, starting 1-month post-bariatric surgery (BS) in addition to standard medical care, while the CG received medical care recommendations only. Knee and trunk MS was assessed by isokinetic dynamometry pre-surgery, 1-, 6-, and 12-month post-surgery, while body composition was assessed by dual-energy X-ray absorptiometry.

RESULTS

The MEP did not significantly impact absolute MS in the dominant knee and trunk regions at 6- and 12-month post-BS. However, relative MS showed significant improvements. At 6-month post-BS, knee flexion at 60°/s relative to body weight (BW) increased significantly (p = 0.047), as did knee extension at 180°/s relative to BW (p = 0.009), and knee extension at 60°/s relative to total lean mass (p=0.040). At 12-month post-BS, knee flexion at 60°/s relative to BW also significantly improved (p=0.038).

CONCLUSION

While absolute MS was not significantly improved with MEP, this study found significant enhancements in relative MS, particularly in dominant knee flexion post-MEP participation. Further research should explore different exercise intensities and frequencies to optimize postoperative MS recovery post-BS.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT02843048).

Short-term effects of Roux-en-Y gastric bypass or gastric sleeve on bone mineral density and calciotropic hormones: a systematic review and meta-analysis

Roux-en-Y gastric bypass (RYGB) and gastric sleeve (GS) have been associated with significant reductions in bone mineral density (BMD) and fluctuations in serum levels of calciotropic hormones. These changes pose a risk to bone health. The study assessed the short-term (12 and 24 months) effects of RYGB and GS on BMD and calciotropic hormones. PubMed, Embase, and Cochrane Library databases were searched. Analyses considered follow-up (12 and 24 months) with BMD as main outcome at three sites (femoral neck, total hip, and lumbar spine) and one for each calciotropic hormone (25 OH vitamin D and parathyroid hormone [PTH]). Estimated effect sizes were calculated as standardized mean differences (SMD), confidence interval of 95%, and P value. Nine studies totaling 473 participants (RYGB = 261 and GS = 212) were included. RYGB resulted in lower BMD than GS at 12 months for femoral neck (SMD = -0.485, 95% CI [-0.768, -0.202], P = .001), lumbar spine (SMD = -0.471, 95% CI [-0.851, -0.092], P = .015), and total hip (SMD = -0.616, 95% CI [-0.972, -0.259], P = .001), and at 24 months for total hip (SMD = -0.572, 95% CI [-0.907, -0.238], P = .001). At 24 months, 25 OH vitamin D was lower in RYGB than GS (SMD = -0.958 [-1.670, -0.245], P = .008) and PTH levels were higher in RYGB than in GS (SMD = 0.968 [0.132, 1.804, P = .023]). RYGB demonstrated significant reduction in regional BMD. It also induces lower serum 25 OH vitamin D and higher PTH levels than GS. The results support the need for preventive bone health measures in the short-term postoperative period, especially in the case of RYGB.

Obesity and Skeletal Fragility

Skeletal fracture has recently emerged as a complication of obesity. Given the normal or better than normal bone mineral density (BMD), the skeletal fragility of these patients appears to be a problem of bone quality rather than quantity. Type 2 diabetes mellitus (T2DM), the incidence of which increases with increasing body mass index, is also associated with an increased risk for fractures despite a normal or high BMD. With the additional bone pathology from diabetes itself, patients with both obesity and T2DM could have a worse skeletal profile. Clinically, however, there are no available methods for identifying those who are at higher risk for fractures or preventing fractures in this subgroup of patients. Weight loss, which is the cornerstone in the management of obesity (with or without T2DM), is also associated with an increased risk of bone loss. This review of the literature will focus on the skeletal manifestations associated with obesity, its interrelationship with the bone defects associated with T2DM, and the available approach to the bone health of patients suffering from obesity.

Effects of a supervised exercise training on body composition after bariatric surgery: a randomized controlled trial

OBJECTIVE

This study aimed to determine the effects of a multicomponent exercise intervention during the first year post-bariatric surgery (BS) on body composition, weight loss (WL), energy expenditure, and nutrient intake.

METHODS

A total of 84 patients were included in this study and were randomly assigned to either an exercise group (n = 41) or a control group (n = 20). The exercise group participated in a multicomponent exercise program that began 1-month post-BS, whereas the control group received only standard medical care post-BS. Body composition was assessed by dual-energy x-ray absorptiometry, and physical activity energy expenditure was assessed by accelerometers. Nutritional intake was assessed through a 4-day food diary.

RESULTS

A total of 6-months post-BS, exercise was found to be effective in mitigating the loss of lower-limb and appendicular lean mass (LM), as well as favoring trunk fat mass (FM) loss. Moreover, it further decreased percent FM and promoted additional excess WL. After 12 months, exercise not only reduced waist circumference but also helped to lessen the loss of total, trunk, and appendicular LM.

CONCLUSIONS

Exercise further induced trunk fat mass, percent FM, excess WL, and waist circumference reductions. Moreover, exercise attenuated the loss of total and regional LM.

Nutrition, Physical Activity, and Prescription of Supplements in Pre- and Post-bariatric Surgery Patients: An Updated Comprehensive Practical Guideline

Only in the USA, 315 billion dollars are spent annually on the medical cost of obesity in adult patients. Till now, bariatric surgery is the most effective method for treating obesity and can play an essential role in reducing the direct and indirect costs of obesity treatment. Nonetheless, there are few comprehensive guidelines which include nutrition, physical activity, and supplements, before and after surgery. The purpose of the present narrative review is to provide an updated and comprehensive practical guideline to help multidisciplinary teams. The core keywords include nutrition, diet, physical activity, exercise, supplements, macronutrients, micronutrients, weight reduction, bariatric surgery, Roux-en-Y Gastric Bypass, Sleeve Gastrostomy, Laparoscopic Adjustable Gastric Banding, and Biliopancreatic diversion with duodenal switch which were searched in databases including PubMed/Medline, Cochrane, and some other sources such as Google Scholar. We answered questions in five important areas: (a) nutritional strategies before bariatric surgery, (b) nutrition after bariatric surgery, (c) physical activity before and after bariatric surgery, (d) weight regain after bariatric surgery, and (e) micronutrient assessments and recommendations before and after bariatric surgery. Some new items were added in this updated guideline including "weight regain" and "pregnancy after bariatric surgery." Other fields were updated based on new evidence and guidelines.

French recommendations on the prevention and treatment of osteoporosis secondary to bariatric surgery

INTRODUCTION

This article presents the initial recommendations of the Groupe de Recherche et d'Information sur les Ostéoporoses (Osteoporosis Research and Information Group [GRIO]) and the Société Française de Rhumatologie (French Rheumatology Society [SFR]) on the prevention and treatment of osteoporosis secondary to bariatric surgery.

METHODS

The recommendations were produced by a working group comprising 4 expert rheumatologists, 3 medically qualified nutritionists, 2 obesity surgeons, 1 physical activity specialist, and 1 patient-association representative.

RESULTS

The following generally recommended measures apply to all patients with an indication for bariatric surgery or who have already undergone bariatric surgery: normalize calcium and protein intake, attain a 25(OH) vitamin D concentration of between 30 and 60ng/mL; prevent the risk of falls, and introduce a suitable regimen of physical activity. An initial assessment of fracture risk should be routinely performed - ideally before the first bariatric surgery procedure - (i) in the case of RYGB and biliopancreatic diversion, regardless of age, (ii) in patients at high risk of fracture, regardless of age, and (iii) in all menopausal women and all men ≥ 50 years old, regardless of the type of bariatric surgical procedure. The fracture risk assessment is based on a determination of osteoporosis risk factors and bone mineral density measurements. Anti-osteoporosis treatment - zoledronic acid as the first line of treatment - is indicated for menopausal women and men ≥ 50 years old with (i) a history of severe fracture, regardless of T-score, (ii) a history of non-severe fracture and a T-score ≤ -1, and (iii) no history of fracture and a T-score ≤ -2.

CONCLUSIONS

There is an increased risk of fracture after bariatric surgery. Clinicians should focus their attention on patients at high fracture risk such as postmenopausal women and men older than 50 years. More research is necessary to direct and support guidelines.

Exercise and bariatric surgery: A systematic review and meta-analysis of the feasibility and acceptability of exercise and controlled trial methods

This systematic review and meta-analysis assessed the feasibility and acceptability of exercise and controlled trial methods in adults awaiting or having undergone bariatric surgery (BS). Search methods used to identify relevant articles were inclusion of articles identified in a systematic review, new database search of articles published 2019-2021, and hand searching reference lists. Titles/abstracts and full-texts were screened by two reviewers independently against inclusion criteria: adults awaiting or having undergone BS, controlled trial, exercise group compared with a comparison group without exercise. Twenty-eight articles were reviewed; most interventions were supervised, performed after BS, and lasted ≤13 weeks. Pooled data for exercise intervention attendance and dropout rates were 84% (k = 10) and 5% (k = 19), respectively, though possibly misestimated due to poor/selective reporting. Median study and recruitment duration were 18 weeks and 24 months, respectively, with a pooled enrollment rate of 2.5 participants/month. Pooled data for refusal to participate, enrollment, and retention rates were 23% (k = 16), 43% (k = 18), and 87% (k = 26), respectively. Despite the lack of data available in studies included, exercise and controlled trial methods seem feasible and acceptable for adults awaiting or having undergone BS. To better identify methodological or practical challenges, and assess bias, better reporting of feasibility and acceptability indicators is needed in future studies.

Effect of physical exercise on muscle strength in adults following bariatric surgery: A systematic review and meta-analysis of different muscle strength assessment tests

Individuals following bariatric surgery are considered at high risk for the development of sarcopenic obesity (excess fat mass, low muscle mass and low physical function), and exercise may play an important role in its prevention and treatment. We systematically reviewed 5 scientific databases (Embase, Medline, Scopus, SPORTDiscus, and Web of Science) and 2 grey literature databases (ProQuest and Google Scholar) for clinical trials that evaluated the effect of exercise on muscle strength in adults following bariatric surgery and conducted a separate meta-analysis for studies that used different muscle strength tests. Random-effect models, restricted maximum likelihood method and Hedges’ g were used. The review protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42020152142). Fifteen studies were included (638 patients), none had a low risk of bias, and all were included in at least 1 of the 5 meta-analyses (repetition maximum [lower and upper limbs], sit-to-stand, dynamometer, and handgrip tests). Exercise interventions improved both upper (effect size, 0.71; 95% CI, 0.41–1.01; I² = 0%) and lower (effect size, 1.37; 95% CI, 0.84–1.91; I² = 46.14) limb muscle strength, as measured by repetition maximum tests. Results were similar for the sit-to-stand (effect size, 0.60; 95% CI, 0.20–1.01; I² = 68.89%) and dynamometer (effect size, 0.46; 95% CI, 0.06–0.87; I² = 31.03%), but not for the handgrip test (effect size, 0.11; 95% CI, -0.42–0.63; I² = 73.27%). However, the certainty level of the meta-analyses was very low. Exercise with a resistance training component performed post bariatric surgery may improve muscle strength, which is related to sarcopenic obesity, functional capacity, and mortality risk, therefore should be included in the follow-up.

Effects of a Multicomponent Exercise Training Program on Balance Following Bariatric Surgery

Patients who undergo bariatric surgery (BS) have an increased risk of falls. Our aim was to determine if a multicomponent exercise intervention after BS improves balance. Eighty-four patients with obesity enrolled for BS were recruited and 1 month after BS randomly allocated to a control (CG; standard medical care) or exercise group (EG; exercise plus standard medical care) consisting of a supervised multicomponent training program (3d/week; 75 min/session; 5 months). Anthropometry, lower limb muscle strength (isokinetic dynamometer), vitamin D (ELISA) and balance in bipedal stance (force platform) were assessed pre-BS, 1 month and 6 months post-BS. One month post-BS, significant balance improvements were observed, namely in antero-posterior center of gravity (CoG) displacement and velocity, and medio-lateral and total CoG velocity. Between 1- and 6-months post-BS, improvements in balance were observed only in the EG, with a significant treatment effect on CoG displacement area and antero-posterior CoG displacement. No significant differences were observed between EG and CG over time in any of the anthropometric, muscle strength, and vitamin D variables assayed. In conclusion, a multicomponent exercise intervention program improves some balance parameters in patients with severe obesity following BS and therefore should be part of post-BS follow-up care as a potential strategy to reduce falls and associated injuries.

Exercise/Physical Activity in Individuals with Type 2 Diabetes: A Consensus Statement from the American College of Sports Medicine

ABSTRACT

This consensus statement is an update of the 2010 American College of Sports Medicine position stand on exercise and type 2 diabetes. Since then, a substantial amount of research on select topics in exercise in individuals of various ages with type 2 diabetes has been published while diabetes prevalence has continued to expand worldwide. This consensus statement provides a brief summary of the current evidence and extends and updates the prior recommendations. The document has been expanded to include physical activity, a broader, more comprehensive definition of human movement than planned exercise, and reducing sedentary time. Various types of physical activity enhance health and glycemic management in people with type 2 diabetes, including flexibility and balance exercise, and the importance of each recommended type or mode are discussed. In general, the 2018 Physical Activity Guidelines for Americans apply to all individuals with type 2 diabetes, with a few exceptions and modifications. People with type 2 diabetes should engage in physical activity regularly and be encouraged to reduce sedentary time and break up sitting time with frequent activity breaks. Any activities undertaken with acute and chronic health complications related to diabetes may require accommodations to ensure safe and effective participation. Other topics addressed are exercise timing to maximize its glucose-lowering effects and barriers to and inequities in physical activity adoption and maintenance.

The Effect of Exercise for the Prevention of Bone Mass After Bariatric Surgery: a Systematic Review and Meta-analysis

We aimed to assess if exercise applied after bariatric surgery (BS) improves bone mineral density (BMD) compared to usual care. Systematic search was conducted up to January 2021. Effect measures were determined using standardized mean difference (SMD) with 95% confidence interval (CI). Certainty evidence was assessed according to GRADE. Four clinical trials encompassing 340 patients were included. Exercise induced a positive BMD effect at total hip (SMD = 0.37 [95% CI 0.02, 0.71]; very low certainty evidence), femoral neck (SMD = 0.63 [95% CI 0.19, 1.06]; low certainty evidence), lumbar spine (SMD = 0.41 [95% CI 0.19, 0.62]; low certainty evidence), and 1/3 radius (SMD = 0.58 [95% CI 0.19, 0.97]; low certainty evidence). Exercise undertaken after BS seems to induce a positive effect on BMD.

The magnitude and progress of lean body mass, fat-free mass, and skeletal muscle mass loss following bariatric surgery: A systematic review and meta-analysis

Postbariatric loss of muscle tissue could negatively affect long-term health due to its role in various bodily processes, such as metabolism and functional capacity. This meta-analysis aimed to unravel time-dependent changes in the magnitude and progress of lean body mass (LBM), fat-free mass (FFM), and skeletal muscle mass (SMM) loss following bariatric surgery. A systematic literature search was conducted in Pubmed, Embase, and Web of Science. Fifty-nine studies assessed LBM (n = 37), FFM (n = 20), or SMM (n = 3) preoperatively and ≥1 time points postsurgery. Random-effects meta-analyses were performed to determine pooled loss per outcome parameter and follow-up time point. At 12-month postsurgery, pooled LBM loss was -8.13 kg [95%CI -9.01; -7.26]. FFM loss and SMM loss were -8.23 kg [95%CI -10.74; -5.73] and -3.18 kg [95%CI -5.64; -0.71], respectively. About 55% of 12-month LBM loss occurred within 3-month postsurgery, followed by a more gradual decrease up to 12 months. Similar patterns were seen for FFM and SMM. In conclusion, >8 kg of LBM and FFM loss was observed within 1-year postsurgery. LBM, FFM, and SMM were predominantly lost within 3-month postsurgery, highlighting that interventions to mitigate such losses should be implemented perioperatively.

Bariatric surgery and skeletal health: A narrative review and position statement for management by the European Calcified Tissue Society (ECTS)

CONTEXT

Numerous studies have demonstrated detrimental skeletal consequences following bariatric surgery.

METHODS

A working group of the European Calcified Tissue Society (ECTS) performed an updated review of existing literature on changes of bone turnover markers (BTMs), bone mineral density (BMD), and fracture risk following bariatric surgery and provided advice on management based on expert opinion.

LITERATURE REVIEW

Based on observational studies, bariatric surgery is associated with a 21-44% higher risk of all fractures. Fracture risk is time-dependent and increases approximately 3 years after bariatric surgery. The bariatric procedures that have a malabsorptive component (including Roux-en-Y Gastric bypass (RYGB) and biliopancreatic diversion (BPD)) have clearly been associated with the highest risk of fracture. The extent of high-turnover bone loss suggests a severe skeletal insult. This is associated with diminished bone strength and compromised microarchitecture. RYGB was the most performed bariatric procedure worldwide until very recently, when sleeve gastrectomy (SG) became more prominent. There is growing evidence that RYGB is associated with greater reduction in BMD, greater increase in BTMs, and higher risk of fractures compared with SG but RCTs on optimal management are still lacking.

EXPERT OPINION

In all patients, it is mandatory to treat vitamin D deficiency, to achieve adequate daily calcium and protein intake and to promote physical activity before and following bariatric surgery. In post-menopausal women and men older than 50 years, osteoporosis treatment would be reasonable in the presence of any of the following criteria: i) history of recent fragility fracture after 40 years of age, ii) BMD T-score ≤ -2 at hip or spine, iii) FRAX score with femoral neck BMD exceeding 20% for the 10-year major osteoporotic fracture probability or exceeding 3% for hip fracture. Zoledronate as first choice should be preferred due to intolerance of oral formulations and malabsorption. Zoledronate should be used with caution due to hypocemia risk. It is recommended to ensure adequate 25-OH vitamin D level and calcium supplementation before administering zoledronate.

CONCLUSIONS

The bariatric procedures that have a malabsorptive component have been associated with the highest turnover bone loss and risk of fracture. There is a knowledge gap on osteoporosis treatment in patients undergoing bariatric surgery. More research is necessary to direct and support guidelines.

Effect of exercise training before and after bariatric surgery: A systematic review and meta-analysis

We aimed to assess the effectiveness of exercise training programs in adults with severe obesity undergoing bariatric surgery. A systematic search of controlled trials published up to October 2019 that assigned participants to either a preoperative or postoperative exercise training group or a nonexercise group was performed. Meta-analyses were conducted using random-effects models. Twenty-two training programs were assessed (18 performed after bariatric surgery). The effect of preoperative exercise training on postsurgery outcomes was reported in only one study. Compared with the control condition without exercise, postoperative exercise training led to higher weight loss (N = 14, mean difference [95% CI] = -1.8 [-3.2; -0.4] kg, P = 0.01), fat loss (N = 9, P = 0.01), increase in VO₂ max (N = 8, P < 0.0001), and increase in muscle strength (N = 9, P < 0.0001). No significant effect was found on lean body mass (N = 11). Preliminary evidence suggests a beneficial effect of postoperative exercise training on bone mineral density (N = 3, P < 0.001) and weight maintenance after the end of the intervention (N = 2, P < 0.001) but no significant effect on quality of life (N = 2), habitual physical activity (N = 2), or cardiometabolic outcomes (N < 4). In conclusion, exercise training performed after bariatric surgery improves physical fitness and leads to a small additional weight and fat loss and may prevent bone loss and weight regain after bariatric surgery.

Zoledronic acid for prevention of bone loss in patients receiving bariatric surgery

Purpose

Bariatric surgery is an effective treatment for severe obesity but causes substantial bone loss and increased risk of fractures. To date, there have been no studies examining whether pharmacologic treatments can prevent bone loss after bariatric surgery. We performed an exploratory study to examine the preliminary safety and efficacy of zoledronic acid (ZOL), a potent anti-resorptive bisphosphonate, to suppress bone turnover markers (BTM) and prevent declines in bone mineral density (BMD) after Roux-en-Y gastric bypass (RYGB) surgery.

Methods

We performed an open-label pilot study of pre-operative ZOL in postmenopausal women with obesity who were planning RYGB (n = 4). A single dose of zoledronic acid 5 mg was given intravenously prior to RYGB. Serum bone biochemistries including C-telopeptide (CTX) and procollagen type 1 N-terminal propeptide (P1NP) were measured at multiple timepoints throughout the 24-week study. BMD was also obtained at the spine and hip by dual-energy x-ray absorptiometry (DXA) and at the trabecular spine by quantitative computed tomography (QCT) at pre-operative baseline and 24 weeks. Results were compared against pre-operative baseline and against changes among RYGB historical controls (n = 10).

Results

At 2 weeks after RYGB, there was a nonsignificant trend for CTX and P1NP levels to be lower than baseline levels in the ZOL group. By 24 weeks after RYGB, however, participants who received ZOL had a significant increase in CTX above pre-operative baseline (+0.228 ± 0.117 ng/dL, p = 0.030) but this CTX rise was less than that observed in the controls (+0.601 ± 0.307 ng/dL, p = 0.042 between groups). Despite ZOL use, participants had significant areal BMD loss at the total hip as compared to pre-operative baseline (-4.2 ± 1.5%, p = 0.012) that was similar in magnitude to total hip BMD loss in the controls (-5.5 ± 3.9%, p = 0.005). There was a suggestion that the ZOL group might be protected against trabecular spine volumetric bone loss as compared to the control group (+4.8 ± 8.0% vs. -5.9 ± 7.0%, p = 0.075 between groups). Serum calcium, 25-hydroxyvitamin D, and parathyroid hormone did not change in either group. No hypocalcemia or serious adverse events were reported after ZOL.

Conclusion

In this proof of concept study, a single dose of ZOL prior to RYGB appeared to transiently mitigate but not fully prevent high bone turnover in the acute postoperative period. At 24 weeks after RYGB, our preliminary data suggest that ZOL was not sufficient to prevent bone loss at the hip, although it may preserve bone density at the trabecular spine. Further prospective, controlled studies are needed to confirm our findings and to identify the best strategies for preventing bone loss in bariatric patients receiving RYGB.