The Impact of Vitamin D, Calcium, Protein Supplementation, and Physical Exercise on Bone Metabolism After Bariatric Surgery: The BABS Study

Short-Term Changes on Body Composition and Bone Mass After One-Anastomosis Gastric Bypass: a Prospective Observational Study

PURPOSE

Bariatric surgery generates a large weight loss. It is considered a successful surgery when 50% of the excess weight loss is reached. However, this measure does not include some variables that may have a direct impact on a patient's health, such as fat-free mass (FFM) or bone mass. Therefore, the aim of this study is to evaluate body composition and bone mass in patients undergoing one-anastomosis gastric bypass (OAGB).

METHODS

A prospective observational study was performed in patients undergoing OAGB. Body composition and bone mass were evaluated by bioelectrical impedance analysis at baseline (1 day prior to surgery), at 6 and 12 months after surgery.

RESULTS

A total of 94 patients (67% females and 33% males) were included in the study. The excess BMI loss at 6 and 12 months after surgery was 97.9 ± 20.1% and 110.2 ± 30.5% respectively. The FFM showed a reduction of 6.6 ± 4.8 kg (p < 0.01) 6 months after surgery and of 7.9 ± 4.9 kg (p < 0.01) at 12 months, meaning a decrease of 10.5 ± 7.3% and a 12.9 ± 6.6% respectively. The bone mass decrease was 10.1 ± 6.9% (p < 0.01) and 12.9 ± 6.5% (p < 0.01) at 12 months after OAGB.

CONCLUSIONS

OAGB obtains a relevant weight loss in patients with morbid obesity, mainly, due to fat mass reductions. However, this procedure also provokes FFM and bone mass decreases, especially in females, but not significantly greater than other restrictive or mixed procedures.

Long-Term Effects of Roux-en-Y Gastric Bypass and Sleeve Gastrectomy on Bone Mineral Density: a 4-Year Longitudinal Study

INTRODUCTION

Bone mineral density (BMD) declines in the initial years after bariatric surgery, but long-term skeletal effects are unclear and comparisons between sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) are rare.

DESIGN AND METHODS

An observational longitudinal study of obese patients undergoing SG or RYGB was performed. Whole-body (WB) BMD, along with BMD of the total hip (TH), femoral neck (FN), and lumbar spine (LS), was measured by dual-energy X-ray absorptiometry (DXA) before surgery and yearly thereafter for 4 years. Calciotropic hormones were also measured.

RESULTS

Forty-seven patients undergoing RYGB surgery and 28 patients undergoing SG were included. Four years after RYGB, BMD declined by 2.8 ± 5.8% in LS, 8.6 ± 5% in FN, 10.9 ± 6.3% in TH, and 4.2 ± 6.2% in WB, relative to baseline. For SG, BMD declined by 8.1 ± 5.5% in FN, 7.7 ± 6% in TH, 2.0 ± 7.2% in LS, and 2.5 ± 6.4% in WB after 4 years, relative to baseline. Vitamin D levels increased with supplementation in both groups. Whereas parathyroid hormone levels increased slightly in the RYGB group, they decreased modestly in the SG group (P < 0.05 in both groups).

CONCLUSIONS

Bone loss after 4 years was comparable between the two procedures, although RYGB was associated with a slightly greater decrease at the TH than SG. Bone health should therefore be monitored after both RYGB and SG.

Towards Optimized Care After Bariatric Surgery by Physical Activity and Exercise Intervention: a Review

Although there is growing evidence on the importance of physical activity and exercise intervention after bariatric surgery, it remains to be clarified as to why and how post-operative exercise intervention should be implemented. In this narrative and practically oriented review, it is explained why exercise interventions and physical activity are important after bariatric surgery, how to prescribe exercise and monitor physical activity and how and when physical fitness, muscle strength, fat (-free) mass and bone mineral density could be assessed during follow-up. It is suggested that the inclusion of physical activity and exercise training in the clinical follow-up trajectory could be of great benefit to bariatric surgery patients, since it leads to greater improvements in body composition, bone mineral density, muscle strength and physical fitness.

Long-term Bone Loss and Deterioration of Microarchitecture After Gastric Bypass in African American and Latina Women

CONTEXT

The prevalence of obesity is burgeoning among African American and Latina women; however, few studies investigating the skeletal effects of bariatric surgery have focused on these groups.

OBJECTIVE

To investigate long-term skeletal changes following Roux-en-Y gastric bypass (RYGB) in African American and Latina women.

DESIGN

Four-year prospective cohort study.

PATIENTS

African American and Latina women presenting for RYGB (n = 17, mean age 44, body mass index 44 kg/m2) were followed annually for 4 years postoperatively.

MAIN OUTCOME MEASURES

Dual-energy x-ray absorptiometry (DXA) measured areal bone mineral density (aBMD) at the spine, hip, and forearm, and body composition. High-resolution peripheral quantitative computed tomography measured volumetric bone mineral density (vBMD) and microarchitecture. Individual trabecula segmentation-based morphological analysis assessed trabecular morphology and connectivity.

RESULTS

Baseline DXA Z-Scores were normal. Weight decreased ~30% at Year 1, then stabilized. Parathyroid hormone (PTH) increased by 50% and 25-hydroxyvitamin D was stable. By Year 4, aBMD had declined at all sites, most substantially in the hip. There was significant, progressive loss of cortical and trabecular vBMD, deterioration of microarchitecture, and increased cortical porosity at both the radius and tibia over 4 years. There was loss of trabecular plates, loss of axially aligned trabeculae, and decreased trabecular connectivity. Whole bone stiffness and failure load declined. Risk factors for bone loss included greater weight loss, rise in PTH, and older age.

CONCLUSIONS

African American and Latina women had substantial and progressive bone loss, deterioration of microarchitecture, and trabecular morphology following RYGB. Further studies are critical to understand the long-term skeletal consequences of bariatric surgery in this population.

The effect of additional protein on lean body mass preservation in post-bariatric surgery patients: a systematic review

BACKGROUND

As result of bariatric surgery, patients are susceptible to protein deficiency which can result in undesirable lean body mass (LBM) loss. Consumption of high-protein diets or supplements could counteract this, but evidence about the effect is scarce. This paper systematically reviewed the literature to determine the effect of additional protein intake (≥60 g/day) on LBM preservation in post-bariatric patients.

METHODS

An electronic search of PubMed, EMBASE and the Cochrane Library was conducted. Studies were included if patients received a high-protein diet or protein supplements for at least one month, and LBM was assessed. The primary outcome was difference in mean LBM loss between the experimental (protein) and control group. Secondary outcomes were differences in body fat mass, total body water, body mass index and resting metabolic rate.

RESULTS

Two of the five included studies (n = 223) showed that consumption of proteins resulted in significant LBM preservation. Only one study reported a significant difference in the reduction of body fat mass and resting metabolic rate in favour of a high-protein diet, but none of the studies showed a significant difference in total body water loss or body mass index change between the two groups.

CONCLUSIONS

This paper showed inconclusive evidence for LBM preservation due to protein supplementation or a high-protein diet in post-bariatric patients. This outcome might be subjected to certain limitations, including a lack of blinding and a low compliance rate reported in the included studies. More specific and personalized recommendations regarding protein intake may need to be established by high quality research. Studies investigating the quantity (g/day) and quality (whey, casein or soy) of proteins are also needed.

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

Exercise has been suggested as a therapeutic approach to attenuate bone loss induced by bariatric surgery (BS), but its effectiveness remains unclear. Our aim was to determine if an exercise-training program could induce benefits on bone mass after BS. Eighty-four patients, submitted to gastric bypass or sleeve gastrectomy, were randomized to either exercise (EG) or control group (CG). One month post-BS, EG underwent a 11-month supervised multicomponent exercise program, while CG received only standard medical care. Patients were assessed before BS and at 1, 6, and 12 months post-BS for body composition, areal bone mineral density (BMD), bone turnover markers, calciotropic hormones, sclerostin, bone material strength index, muscle strength, and daily physical activity. A primary analysis was conducted according to intention-to-treat principles and the primary outcome was the between-group difference on lumbar spine BMD at 12 months post-BS. A secondary analysis was also performed to analyze if the exercise effect depended on training attendance. Twelve months post-BS, primary analysis results revealed that EG had a higher BMD at lumbar spine (+0.024 g∙cm^-2 [95% confidence interval (CI) 0.004, 0.044]; p = .015) compared with CG. Among total hip, femoral neck, and 1/3 radius secondary outcomes, only 1/3 radius BMD improved in EG compared with CG (+0.013 g∙cm^-2 [95% CI 0.003, 0.023]; p = .020). No significant exercise effects were observed on bone biochemical markers or bone material strength index. EG also had a higher lean mass (+1.5 kg [95% CI 0.1, 2.9]; p = .037) and higher number of high impacts (+51.4 [95% CI 6.6, 96.1]; p = .026) compared with CG. In addition, secondary analysis results suggest that exercise-induced benefits may be obtained on femoral neck BMD but only on those participants with ≥50% exercise attendance compared with CG (+5.3% [95% CI 2.0, 8.6]; p = .006). Our findings suggest that an exercise program is an effective strategy to ameliorate bone health in post-BS patients. © 2020 American Society for Bone and Mineral Research (ASBMR).

Bone Mineral Density and Turnover After Sleeve Gastrectomy and Gastric Bypass: A Randomized Controlled Trial (Oseberg)

CONTEXT

Bariatric surgery, particularly Roux-en-Y gastric bypass (RYGB), is associated with an increased risk of osteoporotic fractures. It is unknown whether RYGB or sleeve gastrectomy (SG) have different effects on bone health.

OBJECTIVE

To compare changes in bone mineral density and markers of bone turnover 1 year after SG and RYGB.

DESIGN, SETTING, PATIENTS, AND INTERVENTIONS

Randomized, triple-blind, single-center trial at a tertiary care center in Norway. The primary outcome was diabetes remission. Patients with severe obesity and type 2 diabetes were randomized and allocated (1:1) to SG or RYGB.

MAIN OUTCOME MEASURES

Changes in areal bone mineral density (aBMD) and bone turnover markers.

RESULTS

Femoral neck, total hip, and lumbar spine aBMD, but not total body aBMD, decreased significantly more after RYGB (n = 44) than after SG (n = 48) (mean [95% confidence interval] between group differences -2.8% [-4.7 to -0.8], -3.0% [-5.0 to -0.9], -4.2% [-6.4 to -2.1], and -0.5% [-1.6 to 0.6], respectively). The increase in procollagen type 1 N-terminal propeptide (P1NP) and C-telopeptide of type I collagen (CTX-1) were approximately 100% higher after RYGB than after SG (between group difference at 1 year, both P < 0.001). The changes in femoral neck, total hip, and lumbar spine aBMDs and the changes in P1NP and CTX-1 were independently associated with the surgical procedure (all P < 0.05) and not weight change.

CONCLUSIONS

Roux-en-Y gastric bypass was associated with a greater reduction in aBMD and a greater increase in bone turnover markers compared with SG. This finding could suggest greater skeletal fragility after RYGB.

Bone Metabolism in Adolescents Undergoing Bariatric Surgery

PURPOSE

The prevalence of childhood obesity has increased over past decades with a concomitant increase in metabolic and bariatric surgery (MBS). While MBS in adults is associated with bone loss, only a few studies have examined the effect of MBS on the growing skeleton in adolescents.

METHODS

This mini-review summarizes available data on the effects of the most commonly performed MBS (sleeve gastrectomy and gastric bypass) on bone in adolescents. A literature review was performed using PubMed for English-language articles.

RESULTS

Dual-energy x-ray absorptiometry (DXA) measures of areal bone mineral density (aBMD) and BMD Z scores decreased following all MBS. Volumetric BMD (vBMD) by quantitative computed tomography (QCT) decreased at the lumbar spine while cortical vBMD of the distal radius and tibia increased over a year following sleeve gastrectomy (total vBMD did not change). Reductions in narrow neck and intertrochanteric cross-sectional area and cortical thickness were observed over this duration, and hip strength estimates were deleteriously impacted. Marrow adipose tissue (MAT) of the lumbar spine increased while MAT of the peripheral skeleton decreased a year following sleeve gastrectomy. The amount of weight loss and reductions in lean and fat mass correlated with bone loss at all sites, and with changes in bone microarchitecture at peripheral sites.

CONCLUSION

MBS in adolescents is associated with aBMD reductions, and increases in MAT of the axial skeleton, while sleeve gastrectomy is associated with an increase in cortical vBMD and decrease in MAT of the peripheral skeleton. No reductions have been reported in peripheral strength estimates.

Effectiveness of a Low-Calorie Diet for Liver Volume Reduction Prior to Bariatric Surgery: a Systematic Review

An energy-restricted diet is often prescribed before bariatric surgery to reduce weight and liver volume. While very-low-calorie diets (VLCDs, 450–800 kcal per day) have shown to be effective, the effectiveness of low-calorie diets (LCDs, 800–1500 kcal per day) is less obvious. The objective of this systematic review was to elucidate the effectiveness of LCD on liver volume reduction in patients awaiting bariatric surgery. Eight studies (n = 251) were included describing nine different diets (800–1200 kcal, 2–8 weeks). An LCD was effective in liver volume reduction (12–27%) and weight loss (4–17%), particularly during the first weeks. The LCD showed an acceptable patients’ compliance. Based on these findings, an LCD (800–1200 kcal), instead of a VLCD, for 2 to 4 weeks should be preferred.

MANAGEMENT OF ENDOCRINE DISEASE: Bone complications of bariatric surgery: updates on sleeve gastrectomy, fractures, and interventions

Despite well recognized improvements in obesity-related comorbidities, increasing evidence implicates bariatric surgery in the onset of adverse skeletal health outcomes. The purpose of this review is to provide a focused update in three critical areas: (i) emergent data on sleeve gastrectomy and bone loss, (ii) evidence linking bariatric surgery to incident fracture, and (iii) intervention strategies designed to mitigate surgical bone loss. Better understanding of these issues will inform our treatment of skeletal health for patients planning bariatric surgery.

Bone Density and Trabecular Morphology at Least 10 Years After Gastric Bypass and Gastric Banding

Roux-en-Y gastric bypass (RYGB) instigates high-turnover bone loss in the initial 5 years after surgery, whereas skeletal changes after adjustable gastric banding (AGB) are less pronounced. Long-term skeletal data are scarce, and the mechanisms of bone loss remain unclear. We sought to examine bone density and microarchitecture in RYGB and AGB patients a decade after surgery and to determine whether prior published reports of bone loss represent an appropriate adaptation to new postsurgical weight. In this cross-sectional study, 25 RYGB and 25 AGB subjects who had bariatric surgery ≥10 years ago were matched 1:1 with nonsurgical controls for age, sex, and current body mass index (BMI). We obtained bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA), volumetric BMD and microarchitecture by high-resolution peripheral quantitative computed tomography (HR-pQCT), trabecular morphology by individual trabecular segmentation, and metabolic bone laboratory results. As compared with BMI-matched controls, RYGB subjects had significantly lower hip BMD, and lower total volumetric BMD at the distal radius and tibia. Substantial deficits in cortical and trabecular microarchitecture were observed in the RYGB group compared to controls, with reduced trabecular plate bone volume fraction and estimated failure load at both the radius and tibia, respectively. Bone turnover markers CTX and P1NP were 99% and 77% higher in the RYGB group than controls, respectively, with no differences in serum calcium, 25-hydroxyvitamin D, or parathyroid hormone. In contrast, the AGB group did not differ from their BMI-matched controls in any measured bone density, microarchitecture, or laboratory parameter. Thus, RYGB, but not AGB, is associated with lower than expected hip and peripheral BMD for the new weight setpoint, as well as deleterious changes in bone microarchitecture. These findings suggest that pathophysiologic processes other than mechanical unloading or secondary hyperparathyroidism contribute to bone loss after RYGB, and have important clinical implications for the long-term care of RYGB patients. © 2020 American Society for Bone and Mineral Research.

Systematic review and meta-analysis of perioperative behavioral lifestyle and nutritional interventions in bariatric surgery: a call for better research and reporting

Bariatric surgery is considered the most effective treatment for people with morbid obesity, and certain interventions could enhance its long-term results. We searched MEDLINE, Embase, Web of Science, CENTRAL, and trial registers up to January 1, 2020. Randomized controlled trials, where behavioral lifestyle or nutritional interventions were provided perioperatively were included. Primary outcome was weight change. Two reviewers independently performed each stage of the review. Altogether 6652 references were screened. 31 studies were included for qualitative synthesis and 22 studies for quantitative synthesis. Interventions varied greatly, thus limiting possibility of synthesizing all results. Six groups of interventions were discerned, and we used standardized mean differences for synthesis. Low to very-low certainty evidence suggests that physical activity, nonvitamin nutritional interventions, vitamins, psychotherapy, and counseling but not combined interventions might bring some benefit regarding short-term postsurgery follow-ups (up to 12 mo), but the estimates varied and results were not statistically significant, except for 12 months follow-ups regarding counseling. Psychotherapy and counseling, but not vitamins and combined interventions, may provide some benefit at longer follow-ups (over 12 mo), but the certainty of evidence was low to very-low and statistically significant results were observed in comparisons including data from single studies with small sample sizes only. Included studies expressed an outcome "weight change" using 20 different measures. Misreporting of data and huge variety of outcomes do not benefit systematic analyses and may possibly lead to confusion of both researchers and readers. We suggest that authors follow a predefined set of outcomes when reporting the results of their studies. The initiative to produce "core outcome set" for clinical trials in bariatric surgery trials is currently underway.

Risedronate to Prevent Bone Loss After Sleeve Gastrectomy: Study Design and Feasibility Report of a Pilot Randomized Controlled Trial

Mounting evidence implicates bariatric surgery as a cause of increased skeletal fragility and fracture risk. Bisphosphonate therapy reduces osteoporotic fracture risk and may be effective in minimizing bone loss associated with bariatric surgery. The main objective of this pilot randomized controlled trial (RCT; Clinical Trial No. NCT03411902) was to determine the feasibility of recruiting, treating, and following 24 older patients who had undergone sleeve gastrectomy in a 6 month RCT examining the efficacy of 150‐mg once‐monthly risedronate (versus placebo) in the prevention of surgical weight‐loss–associated bone loss. Feasibility was defined as: (i) >30% recruitment yield, (ii) >80% retention, (iii) >80% pills taken, (iv) <20% adverse events (AEs), and (v) >80% participant satisfaction. Study recruitment occurred over 17 months. Seventy participants were referred, with 24 randomized (34% yield) to risedronate (n = 11) or placebo (n = 13). Average age was 56 ± 7 years, 83% were female (63% postmenopausal), and 21% were black. The risedronate group had a higher baseline BMI than the placebo group (48.1 ± 7.2 versus 41.9 ± 3.8 kg/m²). The 10‐year fracture risk was low (6.0% major osteoporotic fracture, 0.4% hip fracture); however, three individuals (12.5%, all risedronate group) were osteopenic at baseline. Twenty‐one participants returned for 6‐month follow‐up testing (88% retention) with all (n = 3) loss to follow‐up occurring in the risedronate group. Average number of pills taken among completers was 5.9 ± 0.4 and 6.0 ± 0.0 in the risedronate and placebo groups, respectively (p = 0.21), with active participants taking >80% of allotted pills. Five AEs (3.7% AE rate) were reported; one definitely related, four not related, and none serious. All participants reported high satisfaction with participation in the study. Use of bisphosphonates as a novel therapeutic to preserve bone density in patients who had undergone a sleeve gastrectomy appears feasible and well‐tolerated. Knowledge gained from this pilot RCT will be used to inform the design of an appropriately powered trial.

Clinical Trial Registration

http://clinicaltrials.gov/show/NCT03411902. Weight Loss With Risedronate for Bone Health. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Bone mineral density changes after bariatric surgery

INTRODUCTION

Although bariatric surgery is associated with multiple health benefits, decreased bone mass is a known complication of the procedure. Roux-en-Y gastric bypass (RYGB) is associated with significant bone loss and increased fracture risk. However, data on the effect of sleeve gastrectomy (SG) on bone mineral changes are sparse. The impact of vitamin D and calcium levels on bone mineral density (BMD) after SG is also unknown.

METHODS

A retrospective chart review was performed to include patients who underwent RYGB or SG from 2014 to 2016 at a single institution. Patients were included if bone densitometry was performed preoperatively and within 2 years postoperatively. Serum 25-hydroxy vitamin D and calcium levels were collected preoperatively and at time of bone densitometry scan. BMD and T-score changes at the femoral neck, femoral trochanter, total hip, and lumbar spine were compared between RYGB and SG patients.

RESULTS

A total of 40 patients were included. 24 (60%) of patients underwent RYGB and 16 (40%) patients underwent SG. No statistically significant difference in baseline characteristics was noted between RYGB and SG patients. All measurements, except for serum 25-hydroxy vitamin D, were significantly decreased in RYGB patients, postoperatively. All measurements, except for BMD and T-score at the lumbar spine and serum 25-hydroxy vitamin D, were significantly decreased in SG patients, postoperatively. The extent of decrease in serum 25-hydroxyvitamin D was significantly associated with decreased BMD (p = 0.049) and T-score (p = 0.032) at the lumbar spine. The extent of decrease in serum calcium was significantly associated with decreased BMD (p = 0.046) at the femoral neck.

CONCLUSION

All patients were found to have decreased BMD after RYGB and SG. Surgery type was not a significant risk factor in BMD change. Despite vitamin D and calcium supplementation in all patients, a decrease in vitamin D and calcium levels were associated with a decrease in BMD. Close follow-up and treatment of vitamin D and calcium levels are warranted in all bariatric patients.

Relationships Between Vitamin D Status and PTH over 5 Years After Roux-en-Y Gastric Bypass: a Longitudinal Cohort Study

PURPOSE

Secondary hyperparathyroidism (SHPT) after obesity surgery may affect bone health. Optimal vitamin D levels have not been established to prevent SHPT postoperatively. We investigated whether SHPT differed across threshold levels of serum 25-hydroxyvitamin D (S-25(OH)D) from 6 months up to 5 years after Roux-en-Y gastric bypass (RYGB).

MATERIALS AND METHODS

We included 554 patients at follow-up 5 years postoperatively. Blood samples were analysed for S-25(OH)D, ionized calcium (iCa) and parathyroid hormone (PTH) during follow-up.

RESULTS

PTH and prevalence of SHPT increased from 6 months to 5 years postoperatively, while S-25(OH)D and iCa decreased (all P < 0.001). PTH and SHPT development are related with S-25(OH)D, and PTH differed between all subgroups of S-25(OH)D. SHPT occurred less frequently across all subgroups of S-25(OH)D ≥ 50 nmol/l during follow-up: odds ratio (OR) 0.44 (95% CI 0.36-0.54) in patients with S-25(OH)D ≥ 50 nmol/l, OR 0.38 (0.30-0.49) with S-25(OH)D ≥ 75 nmol/l and OR 0.19 (0.12-0.31) with S-25(OH) D ≥ 100 nmol/l, all compared with S-25(OH)D < 50 nmol/l. At 5 years, 208/554 patients (38%) had SHPT; SHPT was found in 94/188 patients (50%) with S-25(OH)D < 50 nmol/l, in 69/222 (31%) with S-25(OH)D 50-74 nmol/l, in 40/117 (34%) with S-25(OH)D 75-99 nmol/l and in 5/27 (19%) with S-25(OH)D ≥ 100 nmol/l. An interaction existed between S-25(OH)D and iCa. Bone alkaline phosphatase remained increased with SHPT.

CONCLUSIONS

A significant relationship existed between S-25(OH)D and development of PTH and SHPT. The prevalence of SHPT was lower with threshold levels 25(OH)D ≥ 50 nmol/l and ≥ 75 nmol/l over the 5 years, and lowest with S-25(OH)D ≥ 100 nmol/l.

Bone Mineral Density, Parathyroid Hormone, and Vitamin D After Gastric Bypass Surgery: a 10-Year Longitudinal Follow-Up

Background

The aim of the present study was to study longitudinal changes in bone mineral density (BMD), vitamin D, and parathyroid hormone (PTH) levels in females over a 10-year period after laparoscopic Roux-en-Y gastric bypass (LRYGB).

Methods

Twenty-three women, mean age 43.4 ± 8.7 years and mean body mass index (BMI) 44.6 ± 5.17 kg/m² at baseline, were included. BMD, BMI, S-calcium, S-25(OH)-vitamin D, and fP-PTH were measured preoperatively and 2, 5, and 10 years postoperatively.

Results

Ten years after surgery, BMD of the spine and femoral neck decreased by 20% and 25%, respectively. Changes in serum levels of vitamin D, PTH, and calcium over the same period were small.

Conclusion

After LRYGB with subsequent massive weight loss, a large decrease in BMD of the spine and femoral neck was seen over a 10-year postoperative period. The fall in BMD largely occurred over the first 5 years after surgery.

Impact of sleeve gastrectomy on hip structural analysis in adolescents and young adults with obesity

BACKGROUND

Sleeve gastrectomy (SG), the most commonly performed metabolic and bariatric surgery, is associated with reductions in areal bone mineral density at multiple sites, and changes in bone structure at the distal radius and tibia without reductions in strength estimates at these peripheral sites. Data are lacking regarding effects on hip strength estimates.

OBJECTIVE

To evaluate effects of SG on measures of hip structural analysis in adolescents and young adults over 12 months using dual-energy x-ray absorptiometry.

SETTINGS

Translational and Clinical Research Center.

METHODS

We enrolled 48 youth 14- to 22-years old with moderate-to-severe obesity; 24 underwent SG and 24 controls were followed without surgery (18 females, 6 males in each group). Hip structure was assessed using dual-energy x-ray absorptiometry at baseline and 12 months. Analyses are adjusted for age, sex, race, and the baseline bone measure.

RESULTS

The SG group lost 25.9% weight versus .3% in controls. Compared with controls, SG had reductions in narrow neck, intertrochanteric and femoral shaft bone mineral density Z-scores (P ≤ .012). Furthermore, SG had greater reductions in narrow neck and intertrochanteric region (but not femoral shaft) cross-sectional area, cortical thickness, cross-sectional moment of inertia and section modulus, and increases in buckling ratio (P ≤ .039). Differences were attenuated after adjusting for 12-month body mass index change. At 12 months, differences were minimal after adjusting for age, sex, race, and weight.

CONCLUSIONS

Over 12 months, SG had negative effects at the narrow neck and intertrochanteric regions of the hip, but not the femoral shaft. Reduced body mass index may compensate for these deleterious effects on bone.

Fracture Risk After Roux-en-Y Gastric Bypass vs Adjustable Gastric Banding Among Medicare Beneficiaries

Importance

Roux-en-Y gastric bypass (RYGB) is associated with significant bone loss and may increase fracture risk, whereas substantial bone loss and increased fracture risk have not been reported after adjustable gastric banding (AGB). Previous studies have had little representation of patients aged 65 years or older, and it is currently unknown how age modifies fracture risk.

Objective

To compare fracture risk after RYGB and AGB procedures in a large, nationally representative cohort enriched for older adults.

Design, Setting, and Participants

This population-based retrospective cohort analysis used Medicare claims data from January 1, 2006, to December 31, 2014, from 42 345 severely obese adults, of whom 29 624 received RYGB and 12 721 received AGB. Data analysis was performed from April 2017 to November 2018.

Main Outcomes and Measures

The primary outcome was incident nonvertebral (ie, wrist, humerus, pelvis, and hip) fractures after RYGB and AGB surgery defined using a combination of International Classification of Diseases, Ninth Edition and Current Procedural Terminology 4 codes.

Results

Of 42 345 participants, 33 254 (78.5%) were women. With a mean (SD) age of 51 (12) years, recipients of RYGB were younger than AGB recipients (55 [12] years). Both groups had similar comorbidities, medication use, and health care utilization in the 365 days before surgery. Over a mean (SD) follow-up of 3.5 (2.1) years, 658 nonvertebral fractures were documented. The fracture incidence rate was 6.6 (95% CI, 6.0-7.2) after RYGB and 4.6 (95% CI, 3.9-5.3) after AGB, which translated to a hazard ratio (HR) of 1.73 (95% CI, 1.45-2.08) after multivariable adjustment. Site-specific analyses demonstrated an increased fracture risk at the hip (HR, 2.81; 95% CI, 1.82-4.49), wrist (HR, 1.70; 95% CI, 1.33-2.14), and pelvis (HR, 1.48; 95% CI, 1.08-2.07) among RYGB recipients. No significant interactions of fracture risk with age, sex, diabetes status, or race were found. In particular, adults 65 years and older showed similar patterns of fracture risk to younger adults. Sensitivity analyses using propensity score matching showed similar results (nonvertebral fracture: HR 1.75; 95% CI, 1.22-2.52).

Conclusions and Relevance

This study of a large, US population-based cohort including a substantial population of older adults found a 73% increased risk of nonvertebral fracture after RYGB compared with AGB, including increased risk of hip, wrist, and pelvis fractures. Fracture risk was consistently increased among RYGB patients vs AGB across different subgroups, and to a similar degree among older and younger adults. Increased fracture risk appears to be an important unintended consequence of RYGB.

Changes in Bone Mineral Density in Patients with Type 2 Diabetes After Different Bariatric Surgery Procedures and the Role of Gastrointestinal Hormones

BACKGROUND

To compare changes in bone mineral density (BMD) in patients with morbid obesity and type 2 diabetes (T2D) a year after being randomized to metabolic gastric bypass (mRYGB), sleeve gastrectomy (SG), and greater curvature plication (GCP). We also analyzed the association of gastrointestinal hormones with skeletal metabolism.

METHODS

Forty-five patients with T2D (mean BMI 39.4 ± 1.9 kg/m²) were randomly assigned to mRYGB, SG, or GCP. Before and 12 months after surgery, anthropometric, body composition, biochemical parameters, fasting plasma glucagon, ghrelin, and PYY as well as GLP-1, GLP-2, and insulin after a standard meal were determined.

RESULTS

After surgery, the decrease at femoral neck (FN) was similar but at lumbar spine (LS), it was greater in the mRYGB group compared with SG and GCP - 7.29 (4.6) vs. - 0.48 (3.9) vs. - 1.2 (2.7)%, p < 0.001. Osteocalcin and alkaline phosphatase increased more after mRYGB. Bone mineral content (BMC) at the LS after surgery correlated with fasting ghrelin (r = - 0.412, p = 0.01) and AUC for GLP-1 (r = - 0.402, p = 0.017). FN BMD at 12 months correlated with post-surgical fasting glucagon (r = 0.498, p = 0.04) and insulin AUC (r = 0.384, p = 0.030) and at LS with the AUC for GLP-1 in the same time period (r = - 0.335, p = 0.049). However, in the multiple regression analysis after adjusting for age, sex, and BMI, the type of surgery (mRYGB) remained the only factor associated with BMD reduction at LS and FN.

CONCLUSIONS

mRYGB induces greater deleterious effects on the bone at LS compared with SG and GCP, and gastrointestinal hormones do not play a major role in bone changes.

The curious fate of bone following bariatric surgery: bone effects of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) in mice

BACKGROUND

Bone loss and increased fracture risk following bariatric surgery has been reported. We investigated whether the two most commonly performed surgeries, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), lead to bone loss. In addition, we examined whether fortification of the diet with calcium citrate prevents bone loss.

METHODS

We used mouse models for SG and RYGB and compared bone loss with a group of sham mice with similar weight loss. All groups were switched at the time of surgery to a low-fat diet (LFD). We also examined whether fortification of the diet with calcium citrate and vitamin D was able to prevent bone loss.

RESULTS

At 2 weeks we observed no major bone effects. However, at 8 weeks, both trabecular and cortical bone were lost to the same extent after SG and RYGB, despite increased calcium absorption and adequate serum levels of calcium, vitamin D, and parathyroid hormone (PTH). Diet fortification with calcium citrate and vitamin D was able to partially prevent bone loss.

CONCLUSIONS

Both SG and RYGB lead to excess bone loss, despite intestinal adaptations to increase calcium absorption. Fortifying the diet with calcium citrate and vitamin D partly prevented the observed bone loss. This finding emphasizes the importance of nutritional support strategies after bariatric surgery, but also affirms that the exact mechanisms leading to bone loss after bariatric surgery remain elusive and thus warrant further research.

Long-Term Effects in Bone Mineral Density after Different Bariatric Procedures in Patients with Type 2 Diabetes: Outcomes of a Randomized Clinical Trial

There is scant evidence of the long-term effects of bariatric surgery on bone mineral density (BMD). We compared BMD changes in patients with severe obesity and type 2 diabetes (T2D) 5 years after randomization to metabolic gastric bypass (mRYGB), sleeve gastrectomy (SG) and greater curvature plication (GCP). We studied the influence of first year gastrointestinal hormone changes on final bone outcomes. Forty-five patients, averaging 49.4 (7.8) years old and body mass index (BMI) 39.4 (1.9) kg/m², were included. BMD at lumbar spine (LS) was lower after mRYGB compared to SG and GCP: 0.89 [0.82;0.94] vs. 1.04 [0.91;1.16] vs. 0.99 [0.89;1.12], p = 0.020. A higher percentage of LS osteopenia was present after mRYGB 78.6% vs. 33.3% vs. 50.0%, respectively. BMD reduction was greater in T2D remitters vs. non-remitters. Weight at fifth year predicted BMD changes at the femoral neck (FN) (adjusted R²: 0.3218; p = 0.002), and type of surgery (mRYGB) and menopause predicted BMD changes at LS (adjusted R²: 0.2507; p < 0.015). In conclusion, mRYGB produces higher deleterious effects on bone at LS compared to SG and GCP in the long-term. Women in menopause undergoing mRYGB are at highest risk of bone deterioration. Gastrointestinal hormone changes after surgery do not play a major role in BMD outcomes.

Common and Rare Complications of Bariatric Surgery

As the prevalence of obesity has increased, bariatric surgery has become more common because of its proven efficacy at promoting weight loss and improving weight-related medical comorbidities. Although generally successful, bariatric surgery may also lead to complications and negatively affect health. This article highlights some common and rare complications of bariatric surgery. Specifically, it discusses the risk of nutrient deficiencies (which is influenced by surgery type) and their downstream effects, including ill-effects on bone health. Rarer complications, such as postbypass hypoglycemia and alcohol use disorder, are also discussed.

The Skeletal Consequences of Bariatric Surgery

PURPOSE OF REVIEW

This review outlines the recent findings regarding the impact of bariatric surgery on bone. It explores potential mechanisms for skeletal changes following bariatric surgery and strategies for management.

RECENT FINDINGS

Bone loss following bariatric surgery is multifactorial. Probable mechanisms include skeletal unloading, abnormalities in calciotropic hormones, and changes in gut hormones. Skeletal changes that occur after bariatric surgery are specific to procedure type and persist for several years post-operatively. Studies suggest that while bone loss begins early, fracture risk may be increased later in the post-operative course, particularly after Roux-en-Y gastric bypass (RYGB). Further research is needed to assess the extent to which skeletal changes following bariatric surgery result in fragility. Current management should be geared toward prevention of bone loss, correction of nutritional deficiencies, and incorporation of weight bearing exercise. Pharmacologic treatment should be considered for high-risk patients.

Bone outcomes following sleeve gastrectomy in adolescents and young adults with obesity versus non-surgical controls

BACKGROUND

Sleeve gastrectomy is the most commonly performed weight loss surgery in adolescents with moderate-to-severe obesity. While studies in adults have reported on the deleterious effects of gastric bypass surgery on bone structure and strength estimates, data are lacking for the impact of sleeve gastrectomy on these measures in adolescents.

OBJECTIVE

To evaluate the impact of sleeve gastrectomy on bone outcomes in adolescents and young adults over 12 months using dual energy X-ray absorptiometry (DXA) and high resolution peripheral quantitative computed tomography (HRpQCT).

PARTICIPANTS AND METHODS

We enrolled 44 youth 14-22 years old with moderate to severe obesity; 22 underwent sleeve gastrectomy and 22 were followed without surgery (16 females and 6 males in each group). At baseline and 12 months, DXA was used to assess areal bone mineral density (aBMD), HRpQCT of the distal radius and tibia was performed to assess bone geometry, microarchitecture and volumetric BMD (vBMD), and finite element analysis to assess strength estimates (stiffness and failure load). These analyses were adjusted for age, sex, race and the bone measure at baseline. Fasting blood samples were assessed for calcium, phosphorus, and 25(OH) vitamin D (25OHD) levels.

RESULTS

Over 12-months, the surgical group lost 27.2% of body weight compared to 0.1% in the non-surgical (control) group. Groups did not differ for changes in 25OHD levels (p = 0.186). Compared to controls, the surgical group had reductions in femoral neck and total hip aBMD Z-scores (p ≤ 0.0006). At the distal tibia, compared to controls, the surgical group had reductions in cortical area and thickness and trabecular number, and increases in trabecular area and separation (p ≤ 0.026). At the distal radius, the surgical group had greater reductions in trabecular vBMD, than controls (p = 0.010). The surgical group had an increase in cortical vBMD at both sites (p ≤ 0.040), possibly from a decrease in cortical porosity (p ≤ 0.024). Most, but not all, differences were attenuated after adjusting for 12-month change in BMI. Groups did not differ for changes in strength estimates over time, except that increases in tibial stiffness were lower in the surgical group (p = 0.044) after adjusting for 12-month change in BMI.

CONCLUSIONS

Over 12 months, weight loss associated with sleeve gastrectomy in adolescents had negative effects on areal BMD and certain HRpQCT parameters. However, bone strength estimates remained stable, possibly because of a simultaneous decrease in cortical porosity and increase in cortical volumetric BMD. Additional research is necessary to determine the relative contribution(s) of weight loss and the metabolic effects of surgery on bone outcomes, and whether the observed effects on bone stabilize or progress over time.

Bone Turnover Markers After Standard and Distal Roux-en-Y Gastric Bypass: Results from a Randomized Controlled Trial

BACKGROUND

Roux-en-Y gastric bypass is associated with increased risk of bone fractures. Malabsorptive procedures may be associated with secondary hyperparathyroidism and detrimental effects on bone health. We aimed to compare the effects of standard and distal gastric bypass on bone turnover markers 2 years after surgery.

METHODS

Patients with body mass index (BMI) 50-60 kg/m² (n = 113) were randomized to standard or distal gastric bypass, 105 patients (95%) completed 2-year follow-up. Serum C-terminal telopeptide of type I collagen (CTX-1), procollagen type I N-propeptide (PINP), and bone-derived alkaline phosphatase (BALP) was measured at baseline and up to 2 years after surgery. ANCOVA and linear mixed models were used to compare groups.

RESULTS

The levels of bone turnover markers increased significantly in both groups, with no statistically significant difference between groups. Two years after standard and distal gastric bypass mean (SD) CTX-1 were 0.81 (0.32) and 0.83 (0.31) μg/L (p = 0.38), mean PINP was 77.6 (23.2) and 77.7 (29.3) μg/L (p = 0.42), and BALP 47.9 (21.9) vs. 50.7 (19.6) μg/L (p = 0.38), respectively. Multiple linear regression analyses showed that PINP and BALP correlated positively (p = 0.01 and p < 0.001) with PTH, but only BALP was significantly higher in patients with secondary hyperparathyroidism (p = 0.001). Type of surgery, vitamin D serum concentrations, and 2-year BMI were all independently associated with PTH levels.

CONCLUSION

A comparable increase in bone turnover markers 2 years after standard and distal gastric bypass was observed. There was a higher prevalence of secondary hyperparathyroidism after distal gastric bypass, but this did not impact bone turnover markers.

TRIAL REGISTRATION

Clinical Trials.gov number NCT00821197.

Bone Health Following Bariatric Surgery: An Update

Obesity rates are increasing rapidly, and bariatric surgery is currently the most effective tool for weight loss. Recently, bariatric surgery induced bone loss has gained attention. Such detrimental effect on bone is multifactorial and causes may include nutrient deficiencies, gut and gonadal hormonal changes, mechanical unloading, loss of lean mass, increased bone marrow fat, and increased risk of fall. This review describes the available evidence on bone loss and fracture risk following bariatric surgery and summarizes the guidelines on the topic. Increased bone resorption starts early postsurgery, and bone markers peak at 1-2 yr. Across studies, the drop in areal bone mineral density is inconsistent at the lumbar spine, while a 2%-5% drop at 6 mo and a 6%-10.5% at 9-12 mo are observed at the total hip. Conversely, studies using quantitative CT showed a 6%-7% decrease in volumetric bone mineral density at the lumbar spine at 6-12 mo postsurgery. These studies also report significant bone loss at the radius and tibia, in addition to alteration in bone microarchitecture. Fracture risk increases 2 yr after surgery, more so following malabsorptive procedures. Fractures were reported at axial, weight bearing sites and at appendicular sites. The available evidence is very heterogeneous, and mostly derived from studies on Roux-en-y gastric bypass in premenopausal women. Data on restrictive procedures is scarce. Our findings suggest that the early postoperative phase represents the "golden window" to intervene and promote bone health. More research is needed to determine the effect of different bariatric procedures on bone, to identify optimal interventions to prevent bone loss and to characterize high risk individuals who should be targeted.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Impact of Roux-en-Y Gastric Bypass on Bone Remodeling Expressed by the P1NP/βCTX Ratio: a Single-Center Prospective Cohort Study

BACKGROUND

Bariatric surgery seems to decrease bone mineral density and increase the risk of fatigue fractures. P1NP (bone formation) and βCTX (bone resorption) were recently validated as reference bone turnover markers (BTM).

OBJECTIVE

To assess changes in bone remodeling in severely obese patients undergoing Roux-en-Y gastric bypass (RYGB) by using a new composite biomarker, the P1NP/βCTX ratio.

METHODS

We prospectively collected blood samples preoperatively, at 1 month and at 1 year from 114 consecutive RYGB patients from 12/2012 to 04/2014. Repeated measures ANOVA and multiple regression were used for data analysis. Cumulative incidence of fractures was assessed in 06/2018.

RESULTS

The P1NP/βCTX ratio decreased significantly (P < 0.001) from baseline to 1 month and 1 year (180 ± 6.6, 110 ± 4.1, and 132 ± 5.4). The 1-year P1NP/βCTX ratio did not correlate with BMI or ΔBMI, but inversely correlated with age (r = - 0.23, P = 0.014) and with hsCRP (r = - 0.26, P = 0.009), even after adjustment for age, sex, BMI, and lifestyle, and linearly correlated with albumin (r = 0.2, P = 0.037). At baseline, none of these correlations were detectable. Serum for all time-points was available from > 94% of the patients. At a median follow-up of 4.7 years, 8 patients (7.3%) had a bone fracture, all of them traumatic.

CONCLUSION

Following RYGB, bone remodeling increases, with a shift toward degradation. This effect seems to be weight-loss independent and shows a correlation with age, with the level of systemic inflammation, and with nutritional state. The risk of fractures should be assessed systematically in bariatric patients and measures of prevention should be improved accordingly.

Effects of Laparoscopic Sleeve Gastrectomy on Bone Mineral Density and Bone Metabolism in Chinese Patients with Obesity

OBJECTIVE

Laparoscopic sleeve gastrectomy (LSG) is one of the most effective therapies to treat obesity. Due to a lack of longitudinal research, we explored the changes in BMD and bone metabolism in Chinese patients with obesity before and after LSG.

MATERIALS AND METHODS

A total of 49 obese Chinese patients with obesity were recruited from the Second Xiangya Hospital of Central South University. All patients underwent LSG, and the metabolic indicators were evaluated, including the serum osteocalcin (OC), total-terminal propeptide of type I procollagen (TPINP) and carboxy terminal telopeptide of collagen type I (CTX) levels at baseline and 2, 6 and 12 months postoperatively. Dual energy X-ray absorptiometry (DEXA) was used to measure body composition and BMD before and 12 months after LSG.

RESULTS

The body mass index (BMI) significantly decreased at 12 months postoperatively, and no patients developed osteoporosis. The BMD of femoral neck and total hip significantly decreased from the baseline to 12 months postoperatively, while the BMD of lumbar spine did not change significantly. The OC, TPINP and CTX levels significantly increased at 12 months postoperatively. The excess BMI loss (EBMIL) was positively related while the reduction in visceral adipose tissue (VAT) mass was negatively related to the decreases in BMD of the femoral neck and total hip at 12 months postoperatively. The increase in OC was negatively correlated with the decrease in BMD of the femoral neck, while the increase in TPINP was positively correlated with the decrease in BMD of total hip.

CONCLUSION

Based on the 12-month follow-up results, the BMD of the femoral neck and total hip was decreased in Chinese patients with obesity after LSG, while bone remodelling was active. This finding suggested that weight loss, a decrease in the VAT mass and an increase in bone remodelling may be correlated with a reduction in BMD.

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.

Proceedings of the 2019 Santa Fe Bone Symposium: New Concepts in the Care of Osteoporosis and Rare Bone Diseases

The 20th annual Santa Fe Bone Symposium was held August 9-10, 2019, in Santa Fe, New Mexico, USA. This is an annual meeting devoted to clinical applications of recent advances in skeletal research that impact the care of patients with osteoporosis, metabolic bone diseases, and inherited bone diseases. Participants included practicing and academic physicians, fellows, advanced practice providers, fracture liaison service (FLS) coordinators, clinical researchers, and bone density technologists. The symposium consisted of lectures, case presentations, and panel discussions, with an emphasis on learning through interaction of all attendees. Topics included new approaches in the use of anabolic agents for the treatment osteoporosis, a review of important events in skeletal health over the past year, new and emerging treatments for rare bone diseases, the use of genetic testing for bone diseases in clinical practice, medication-associated causes of osteoporosis, new concepts in the use of estrogen therapy for osteoporosis, new Official Positions of the International Society for Clinical Densitometry, skeletal consequences of bariatric surgery, and update on the progress and potential of Bone Health TeleECHO, a virtual community of practice using videoconferencing technology to link healthcare professionals for advancing the care of osteoporosis worldwide. Sessions on rare bone diseases were developed in collaboration with the Rare Bone Disease Alliance. Symposium premeetings included an FLS workshop by the National Osteoporosis Foundation and others devoted to the use of new therapeutic agents for the care of osteoporosis and related disorders.

Effects of Roux-en-Y Gastric Bypass on Osteoclast Activity and Bone Density in Morbidly Obese Patients with Type 2 Diabetes

INTRODUCTION

Roux-en-Y gastric bypass (RYGB) is a well-established treatment for morbid obesity and type 2 diabetes. The effects of RYGB on bone metabolism and bone health are largely unknown.

OBJECTIVE

Determine the changes in osteoclast function and bone density 1 year after RYGB as compared with a control group undergoing a diabetes support and education program (DSE).

DESIGN

A prospective cohort study with patients matched for weight and age assigned to RYGB or DSE.

SETTING

Large academic institution.

PATIENTS OR OTHER PARTICIPANTS

Patients with type 2 diabetes mellitus and morbid obesity (body mass index greater than 35 kg/m2).

INTERVENTION

Subjects either received laparoscopic RYBG or DSE, which consisted of nutritional, exercise, and dietary counseling performed by a certified diabetic educator and a nutritionist three times over a year.

MAIN OUTCOME MEASURE

Osteoclast activity, bone mineral density.

RESULTS

One year after, intervention subjects undergoing RYGB have a 280% increase in osteoclast activity as compared with a 7.6% increase in the DSE control group (P < 0.001). Furthermore, there was a statistically significant increase in sclerostin levels in subjects undergoing RYGB compared with an increase in the control group. The total bone mineral density was statistically unchanged within 1 year of intervention in both groups. A statistically significant decrease in bone mineral density in the left ribs (decrease of 6.8%, P < 0.05) and lumbar spine (decrease of 4.0%, P < 0.05) was seen 1 year after RYGB.

CONCLUSIONS

There is a significant increase in osteoclast activity observed 1 year after RYGB; the long-term clinical implications of this increased bone metabolism are unknown.

Nutritional Deficiencies in Patients with Severe Obesity before Bariatric Surgery: What Should Be the Focus During the Preoperative Assessment?

BACKGROUND

Nutritional deficiencies are a well-recognized long-term complication following bariatric surgery. The presence of preoperative deficiencies has been shown to be predictive of postoperative deficiencies.

OBJECTIVE

The aim of the study was to investigate the prevalence of micronutrient deficiency in a large sample of patients with severe obesity preoperatively, and to determine whether such deficiencies may be related to patient's sex, body mass index, or ethnic subgroup.

DESIGN

A cross-sectional study of data collected at the time of the preoperative evaluation.

PARTICIPANTS/SETTING

Data were collected during the preoperative evaluation of 872 bariatric surgery candidates in a university hospital in Israel between 2011 and 2018. The patients were 72.9% women, with a mean age of 37.9±12.1 years and mean body mass index of 42.4±4.7 MAIN OUTCOME MEASURES: Nutritional deficiencies according to blood assays. Data on anthropometrics, comorbidities, and demographic characteristics was also collected.

STATISTICAL ANALYSES

Baseline differences between patient subgroups were analyzed using independent-samples t test, analysis of variance, or χ² test.

RESULTS

Deficiencies of vitamin D, iron, folate, vitamin B-12, elevated parathyroid hormone and low transferrin saturation were present in 75.2%, 42.6%, 28.5%, 8.5%, 35.5%, and 70% of patients, respectively. Nutritional deficiencies were significantly more common among women compared with men for iron (45.9% vs 33.5%; P=0.002), low transferrin saturation (77.7% vs 44.6%; P<0.001), vitamin D (77.5% vs 69.2%; P=0.019) and elevated parathyroid hormone level (39.5% vs 22.9%; P=0.002). Iron, transferrin saturation, and vitamin D deficiencies were more prevalent in Arab patients compared with Jewish patients: 59.6% vs 36%; P<0.001, 80.2% vs 62.8%; P=0.003, and 85.1% vs 71.6%; P<0.001, respectively. Vitamin D and iron deficiency were more common among higher body mass index subgroups (P=0.004 and P=0.040, respectively).

CONCLUSIONS

The results indicate a high prevalence of nutritional deficiencies, mainly of iron and vitamin D in bariatric surgery candidates. Patients at higher risk for nutritional deficiencies include those with higher body mass index, women, and Arabs.

Proceedings of the 2017 ASPEN Research Workshop-Gastric Bypass: Role of the Gut

The goal of the National Institutes of Health-funded American Society for Parenteral and Enteral Nutrition 2017 research workshop (RW) "Gastric Bypass: Role of the Gut" was to focus on the exciting research evaluating gut-derived signals in modulating outcomes after bariatric surgery. Although gastric bypass surgery has undoubted positive effects, the mechanistic basis of improved outcomes cannot be solely explained by caloric restriction. Emerging data suggest that bile acid metabolic pathways, luminal contents, energy balance, gut mucosal integrity, as well as the gut microbiota are significantly modulated after bariatric surgery and may be responsible for the variable outcomes, each of which was rigorously evaluated. The RW served as a timely and novel academic meeting that brought together clinicians and researchers across the scientific spectrum, fostering a unique venue for interdisciplinary collaboration among investigators. It promoted engaging discussion and evolution of new research hypotheses and ideas, driving the development of novel ameliorative, therapeutic, and nonsurgical interventions targeting obesity and its comorbidities. Importantly, a critical evaluation of the current knowledge regarding gut-modulated signaling after bariatric surgery, potential pitfalls, and lacunae were thoroughly addressed.

A place for vitamin supplementation and functional food in bariatric surgery?

PURPOSE OF REVIEW

This article summarizes recent literature concerning vitamin deficiency and required supplementation post-bariatric surgery, focusing on vitamin D (and associated clinical adverse effect on bone loss) and on the potential implication of the gut microbiota.

RECENT FINDINGS

Bariatric surgery induces weight loss and metabolic improvements yet with major inter-individual variability. If it is efficient in most patients, some display poor response (i.e. patients with the lowest weight loss at 1 year or weight regain afterwards, or patients without metabolic disease remission). Despite systematic vitamin supplementation, some patients develop vitamin deficiencies leading to poor clinical outcomes, among which vitamin D deficiency associated with observed bone mass loss and fractures. Recent mechanistic studies led to understand better the involved physiopathology. Furthermore, different intervention studies tested on top of bariatric surgery (using vitamin, diet, or nutrients acting as functional food) have evaluated whether nutritional adverse outcomes could be improved. Importantly, gut microbiota involved in food digestion and metabolization and vitamin synthesis is largely perturbed during severe obesity and is partially restored post-surgery, yet again with large interindividual variability. Whether differential gut microbiota modification could be associated with vitamin deficiencies is an open question.

SUMMARY

Future clinical research studies will need to evaluate whether add-on intervention to bariatric surgery using vitamin, diet, or specific food items could help prevent nutritional deficiencies and improve clinical response observed post-surgery. Importantly, personalizing the add-on intervention post-surgery upon gut microbiota composition should be tested in predicted poor-responders to surgery as already performed during diet intervention to further improve metabolic health.

Clinical practice guidelines for the perioperative nutrition, metabolic, and nonsurgical support of patients undergoing bariatric procedures - 2019 update: cosponsored by American Association of Clinical Endocrinologists/American College of Endocrinology, The Obesity Society, American Society for Metabolic & Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists

OBJECTIVE

The development of these updated clinical practice guidelines (CPG) was commissioned by the American Association of Clinical Endocrinologists, The Obesity Society, the American Society of Metabolic and Bariatric Surgery, the Obesity Medicine Association, and the American Society of Anesthesiologists boards of directors in adherence to the American Association of Clinical Endocrinologists 2017 protocol for standardized production of CPG, algorithms, and checklists.

METHODS

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

RESULTS

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

CONCLUSIONS

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

Changes in Bone Mineral Density Following Weight Loss Induced by One-Anastomosis Gastric Bypass in Patients with Vitamin D Supplementation

BACKGROUND

Little is known about changes in bone mineral density (BMD) following weight loss after one-anastomosis gastric bypass (OAGB) and the role of serum vitamin D and its supplementation on bone metabolism. We evaluated BMD after OAGB as a function of vitamin D supplementation with respect to a minimum threshold of 25-hydroxy-vitamin-D [25(OH)D] concentration, which could prevent or decelerate an eventual bone loss.

METHODS

Fifty bariatric patients who participated in the randomized controlled trial were included in this analysis. BMD and anthropometric measurements by DXA and laboratory parameters were assessed before (T0), at 6 (T6), and 12 months (T12) after surgery.

RESULTS

OAGB resulted in a 36% total body weight loss with a decrease in body fat and an increase in lean body mass. A significant decrease in BMD was seen in lumbar spine by 7%, left hip 13%, and total body 1%, but not in forearm. Bone turnover markers increased significantly but with normal parathyroid hormone concentrations. Weight loss was not associated with changes in BMD. A serum 25(OH)D concentration > 50 nmol/l at T6 and T12 (adequate-vitamin-D-group; AVD) showed a significant lower bone loss, compared to the inadequate-vitamin-D-group (IVD; < 50 nmol/l). Lower bone loss in the left hip showed a strong correlation with higher 25(OH)D concentrations (r = 0.635, p = 0.003).

CONCLUSION

These findings support a dose effect of vitamin D supplementation on bone health and suggest that 25(OH)D concentrations need to be above 50 nmol/l at least during the first postoperative year to decelerate bone loss in patients undergoing OAGB.

CLINICAL TRIAL REGISTRY NUMBER AND WEBSITE

Clinicaltrials.gov (NCT02092376) at https://clinicaltrials.gov /. EudraCT (2013-003546-16) at https://eudract.ema.europa.eu /.

Multiple vertebral compression fractures after sleeve gastrectomy and a subsequent pregnancy: a case report

We report that a 33-year-old woman developed multiple compression fractures several years after a sleeve gastrectomy followed by pregnancy. Despite normal areal BMD values assessed by dual-energy X-ray absorptiometry and no family history of osteoporosis, the patient demonstrated low lumbar spine trabecular bone score, as well as low peripheral trabecular volumetric BMD and deterioration of trabecular microarchitecture assessed by high-resolution peripheral quantitative computed tomography. Women of reproductive age should be provided with lifestyle management targeting bone health following bariatric surgery.

Exercise Mitigates Bone Loss in Women With Severe Obesity After Roux-en-Y Gastric Bypass: A Randomized Controlled Trial

CONTEXT

Bone loss after bariatric surgery potentially could be mitigated by exercise.

OBJECTIVE

To investigate the role of exercise training (ET) in attenuating bariatric surgery-induced bone loss.

DESIGN

Randomized, controlled trial.

SETTING

Referral center for bariatric surgery.

PATIENTS

Seventy women with severe obesity, aged 25 to 55 years, who underwent Roux-en-Y gastric bypass (RYGB).

INTERVENTION

Supervised, 6-month, ET program after RYGB vs. standard of care (RYGB only).

OUTCOMES

Areal bone mineral density (aBMD) was the primary outcome. Bone microarchitecture, bone turnover, and biochemical markers were secondary outcomes.

RESULTS

Surgery significantly decreased femoral neck, total hip, distal radius, and whole body aBMD (P < 0.001); and increased bone turnover markers, including collagen type I C-telopeptide (CTX), procollagen type I N-propeptide (P1NP), sclerostin, and osteopontin (P < 0.05). Compared with RYGB only, exercise mitigated the percent loss of aBMD at femoral neck [estimated mean difference (EMD), -2.91%; P = 0.007;], total hip (EMD, -2.26%; P = 0.009), distal radius (EMD, -1.87%; P = 0.038), and cortical volumetric bone mineral density at distal radius (EMD, -2.09%; P = 0.024). Exercise also attenuated CTX (EMD, -0.20 ng/mL; P = 0.002), P1NP (EMD, -17.59 ng/mL; P = 0.024), and sclerostin levels (EMD, -610 pg/mL; P = 0.046) in comparison with RYGB. Exercise did not affect biochemical markers (e.g., 25(OH)D, calcium, intact PTH, phosphorus, and magnesium).

CONCLUSION

Exercise mitigated bariatric surgery-induced bone loss, possibly through mechanisms involving suppression in bone turnover and sclerostin. Exercise should be incorporated in postsurgery care to preserve bone mass.

Vitamin D supplementation in obesity and during weight loss: A review of randomized controlled trials

Vitamin D deficiency is common in obese individuals and during weight loss. The recommended vitamin D doses in this specific population are higher than for healthy adults. We reviewed vitamin D supplementation trials in obesity, and during medical or surgical weight loss, and report the effects on 25-hydroxyvitamin D [25(OH)D] concentrations and other relevant outcomes. We conducted a systematic search in PubMed, Medline, Embase and the Cochrane library for relevant randomized controlled trials (RCTs) of oral vitamin D supplementation for at least 3 months in obese individuals without weight loss (OB), and those on medical weight loss (MWL) (2010-2018), and following bariatric surgery (Bar S) (without time restriction). Two reviewers screened the identified citations in duplicate and independently and performed full text screening. One reviewer completed data extraction. We identified 13 RCTs in OB, 6 in MWL and 7 in Bar S. Mean baseline 25(OH)D concentrations ranged between 7 and 27 ng/ml in OB, 15-29 ng/ml in MWL and 15-24 ng/ml in Bar S. In OB (Total N 2036 participants), vitamin D doses of 1600-4000 IU/d increased mean 25(OH)D concentrations to ≥30 ng/ml. Based on three trials during MWL (Total N 359 participants), vitamin D doses of 1200-4600 IU/d for 12 months increased 25(OH)D concentration to ≥30 ng/ml. In Bar S (Total N 615 participants), doses ≥2000 IU/d were needed to reach 30 ng/ml. The change in 25(OH)D concentration was inversely proportional to the administered dose, and to BMI and baseline level with doses of 600-3000 IU/day. With these doses, the change in 25(OH)D concentration [Δ25(OH)D] per 100 IU/d was 0.5-1.2 ng/ml. Three trials assessed bone mineral density as a primary outcome, but only one of them showed a protective effect of vitamin D against bone loss at all sites post-Bar S. There was no effect of vitamin D on weight loss. Data on extra-skeletal parameters, namely glycemic and vascular indices were mostly identified in OB, and findings were inconsistent. In conclusion, Vitamin D doses ≥1600-2000 IU/d may be needed to reach a 25(OH)D concentration of 30 ng/ml in obese individuals and following bariatric surgery. The optimal concentration in this population is unknown, and whether the above doses protect against weight loss induced bone loss and fractures still needs to be confirmed. There is no clear evidence for a beneficial effect of vitamin D supplementation on cardio-metabolic parameters in obese individuals, and data on such parameters with weight loss are very scarce. Well-designed long term RCTs assessing the effect of vitamin D supplementation during weight loss on patient important outcomes are needed.

Risk factors for loss of bone mineral density after curative esophagectomy

Micronutrient and fat malabsorption and altered enteroendocrine signaling occur after esophagectomy for cancer; however, the impact of malnutrition on bone health in this cohort has not been previously investigated. In this study, the prevalence of osteoporosis increased after curative surgery, associated with disease-specific, treatment-related, and population risk factors.

PURPOSE

Improved oncologic outcomes in esophageal cancer (EC) have resulted in increased survivorship and a focus on long-term quality of life. Malnutrition and micronutrient malabsorption are common among patients with EC, but the effect on bone metabolism is not known. The aim of this study was to characterize changes in bone mineral density (BMD) following curative esophagectomy.

METHODS

Consecutive disease-free patients who underwent esophagectomy with gastric conduit for pathologically node-negative disease from 2000 to 2014 were included. BMD was assessed at vertebral levels T12-L5 by computed tomography using a simple trabecular region-of-interest attenuation technique, and serum markers of nutritional status and bone metabolism were examined. Independent risk factors for osteoporosis were identified by multivariable logistic regression.

RESULTS

Seventy-five consecutive patients were studied. Osteoporosis was present in 25% at diagnosis. BMD declined at 1 and 2 years postoperatively (144.3 ± 45.8 versus 128.6 ± 46.2 and 122.7 ± 43.5 Hounsfield Units (HU), P < 0.0001), with increased osteoporosis prevalence to 38% and 44% (P = 0.049), respectively. No significant postoperative change in vitamin D, calcium, or phosphate was observed, but alkaline phosphatase increased significantly (P < 0.001). While female sex (P = 0.004) and ASA grade (P = 0.043) were independently associated with osteoporosis at diagnosis, age (P = 0.050), female sex (P = 0.023), smoking (P = 0.024), and pathologic T stage (P = 0.023) were independently predictive of osteoporosis at 1 year postoperatively.

CONCLUSIONS

Osteoporosis is prevalent among disease-free patients post-esophagectomy for EC, associated with disease-specific, treatment-related, and population risk factors. Strategies which minimize BMD decline should be considered to avoid fragility fractures in this cohort.

VITAMIN D DEFICIENCY AND PARATOHOMMONIUM INCREASE IN LATE POSTOPERATIVE GASTRIC BYPASS IN ROUX-EN-Y

BACKGROUND

Roux-en-Y gastric bypass patients can experience changes in calcium metabolism and hyperparathyroidism secondary to vitamin D deficiency.

AIM

To evaluate nutritional deficiencies related to the calcium metabolism of patients undergoing gastric bypass with a 10-year follow-up.

METHOD

This is a longitudinal retrospective study of patients submitted to Roux-en-Y gastric bypass at a multidisciplinary clinic located in the Brazilian southeast region. The study investigated the results of the following biochemical tests: serum calcium, ionized calcium, vitamin D, and parathormone (PTH). The generalized estimating equations (GEE) determined the nutritional deficiencies using a significance level of 5%.

RESULTS

Among the patients who finished the study (120 months), 82.86% (n=29) had vitamin D deficiency, and 41.94% (n=13) had high PTH. Postoperative time had a significant effect on PTH (p=0.0059). The percentages of patients with vitamin D, serum calcium, and ionized calcium deficiencies did not change significantly over time.

CONCLUSION

One of the outcomes was vitamin D deficiency associated with secondary hyperparathyroidism. These findings reaffirm the importance of monitoring the bone metabolism of patients submitted to Roux-en-Y gastric bypass.

HEADINGS

Calcium deficiency. Vitamin D deficiency. Secondary hyperparathyroidism.

Visceral white adipose tissue and serum proteomic alternations in metabolically healthy obese patients undergoing bariatric surgery

Metabolically healthy obesity is characterized as a comorbidity-free obesity status, however the exact pathogenetic mechanisms implicated in its transition to unhealthy obesity have not yet been unveiled. Our aim was to investigate the effect of metabolic health on the proteomic profile both in serum and visceral fat of morbidly obese subjects. 28 patients undergoing bariatric surgery were prospectively enrolled. They were divided into two groups: metabolically healthy (MHO, n = 18) and unhealthy (MUO, n = 10) obese patients. 30 biomarkers were measured in serum and visceral adipose tissue with the use of targeted proteomic analysis (Luminex assays). TNF weak inducer of apoptosis (TWEAK) (p = 0.043), TNF related apoptosis inducing ligand (TRAIL) (p = 0.037), Growth differentiation factor-15 (GDF-15) (p = 0.04), Resistin (RETN) (p = 0.047), Matrix metalloproteinase-9 (MMP-9) (p = 0.011) and C-terminal telopeptide (ICTP) (p = 0.022) were up-regulated in the MUO group in the visceral white adipose tissue. Moreover, C-C motif ligand-3 (CCL-3) (p = 0.056), Interleukin-20 (IL-20) (p = 0.04), Prokineticin-1 (PROK-1) (p = 0.028) and TWEAK (p = 0.016) were found to be suppressed in the serum of MHO group. Significant correlations between serum and adipose tissue levels of certain cytokines were also observed, while 16 biomarkers were associated with BMI. Our results indicate metabolic health substantially attenuates the expression of TWEAK, TRAIL, GDF-15, RETN, MMP-9 and ICTP expression locally, in the visceral white adipose tissue, and the expression of CCL-3, IL-20, PROK-1 and TWEAK in the peripheral blood. Intriguingly, different cytokines -except for TWEAK- are up-regulated in each site, suggesting that obesity is not a homogenous but a multi-dimensional disease.