Bone and gastric bypass surgery: effects of dietary calcium and vitamin D

Oral vitamin D supplementation for adults with obesity undergoing bariatric surgery

BACKGROUND

Vitamin D deficiency following bariatric surgery is common and is expected to be associated with a deleterious impact on the skeleton. However, the benefits of vitamin D supplementation and the optimal dose in this population is currently unknown. The available guidelines on the topic are derived from experts' opinions, and are not evidence based.

OBJECTIVES

To compare the effects of different doses of vitamin D supplementation (low dose (less than 600 international units (IU)/day), moderate dose (600 IU/day to 3500 IU/day), high dose (greater than 3500 IU/day)) to each other or to placebo in adults living with obesity undergoing bariatric surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, two trial registries, and the reference lists of systematic reviews, articles, and health technology assessment reports without language restrictions. The last search of all databases was 27 June 2023, except Embase, which we searched on 14 August 2015.

SELECTION CRITERIA

We included randomised controlled trials or controlled clinical trials on vitamin D supplementation comparing different doses or comparing vitamin D to placebo in people undergoing bariatric surgery.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Primary outcomes were fractures and adverse events. Secondary outcomes were vitamin D status, all-cause mortality, bone mineral change, secondary hyperparathyroidism, health-related quality of life, and muscle strength. We used GRADE to assess the certainty of the evidence for each outcome in each comparison.

MAIN RESULTS

We identified five trials with 314 participants. We included three trials in the quantitative analysis. Moderate-dose vitamin D compared to placebo One trial compared moderate-dose vitamin D (3200 IU/day) to placebo. Moderate-dose vitamin D, compared to placebo, may improve vitamin D status and may result in little to no difference in the achieved parathyroid hormone level (achieved 25-hydroxyvitamin D level: mean difference (MD) 13.60 ng/mL, 95% confidence interval (CI) 7.94 to 19.26; achieved parathyroid hormone level: -6.60 pg/mL, 95% CI -17.12 to 3.92; 1 study, 79 participants; low-certainty evidence). The trial reported no adverse events in the moderate-dose vitamin D arm, but did not provide any information on adverse events in the placebo arm. There were no data on fractures, all-cause mortality, bone density change, health-related quality of life, and muscle strength. High-dose vitamin D compared to moderate-dose vitamin D Two trials in Roux-en-Y gastric bypass compared moderate-dose (equivalent dose 800 IU/day to 2000 IU/day) to high-dose (equivalent dose 5000 IU/day to 7943 IU/day) vitamin D. The evidence of high-dose vitamin D on adverse events is very uncertain (risk ratio (RR) 5.18, 95% CI 0.23 to 116.56; 2 studies, 81 participants; very low-certainty evidence). High-dose vitamin D may increase 25-hydroxyvitamin D levels compared to a moderate dose at 12 months, but the evidence is very uncertain (MD 15.55 ng/mL, 95% CI 3.50 to 27.61; I2 = 62%; 2 studies, 73 participants; very low-certainty evidence). High-dose vitamin D may have little to no effect on parathyroid hormone levels compared to a moderate dose at 12 months, but the evidence is very uncertain (MD 2.15 pg/mL, 95% CI -21.31 to 17.01; I2 = 0%; 2 studies, 72 participants; very low-certainty evidence). High-dose vitamin D may have little to no effect on mortality and bone mineral density at the lumbar spine, hip, and forearm, but the evidence is very uncertain. There were no data on fractures, health-related quality of life, or muscle strength.

AUTHORS' CONCLUSIONS

No trials reported on fractures and the evidence available on adverse events is scarce. Moderate-dose vitamin D may improve vitamin D status and may result in little to no improvement in parathyroid hormone levels compared with placebo. High-dose vitamin D supplementation (greater than 3500 IU/day) may increase 25-hydroxyvitamin D levels, and may have little to no effect on parathyroid hormone levels, compared to a moderate dose, but the evidence for both is very uncertain. The currently available limited evidence may not have a significant impact on practice. Further studies are needed to explore the impact of vitamin D supplementation on fractures, adverse events, and musculoskeletal parameters in people undergoing bariatric surgery.

Normocalcemic primary hyperparathyroidism: From pathophysiology to clinical management

Normocalcemic primary hyperparathyroidism (NPHPT), a variant of primary hyperparathyroidism (PHPT) characterized by persistently elevated parathyroid hormone (PTH) levels and normal serum calcium, has gained recognition as a substantial subset of PHPT cases. Despite its increasing prevalence, the precise pathophysiology and natural progression of NPHPT remain enigmatic. This in-depth literature review explores recent advancements in our understanding of NPHPT, encompassing pathophysiology, clinical presentation, diagnostic approaches, medical and surgical management options. By synthesizing this wealth of information, this review aims to contribute to a more nuanced and informed approach to the treatment of patients grappling with NPHPT. As our understanding of the condition continues to evolve, the knowledge gathered from this review has the potential to significantly enhance the quality of care and outcomes for individuals afflicted with NPHPT, ultimately improving their overall well-being and prognosis.

Nutritional Challenges and Treatment After Bariatric Surgery

Bariatric surgery is an important weight loss tool in individuals with severe obesity. It is currently the most effective long-term weight loss treatment that lowers obesity-related comorbidities. It also has significant physiological and nutritional consequences that can result in gastrointestinal complications and micronutrient deficiencies. After gastric bypass, clinical events that negatively affect nutritional status include malabsorption, dumping syndrome, kidney stones, altered intestinal bile acid availability, bowel obstruction, ulcers, gastroesophageal reflux, and bacterial overgrowth. Risk factors for poor nutritional status and excessive loss of lean body mass and bone include reduced dietary quality and inadequate intake, altered nutrient absorption, and poor patient compliance with nutrient supplementation. There are unique concerns in adolescents, older individuals, and individuals who become pregnant postoperatively. With careful management, health-care professionals can assist with long-term weight loss success and minimize the risk of acute and long-term nutrition complications after bariatric surgery.

Medication and supplement pharmacokinetic changes following bariatric surgery: A systematic review and meta-analysis

OBJECTIVES

To evaluate the impact of bariatric surgery on the pharmacokinetic (PK) parameters of orally administered medications and supplements.

METHODS

Systematic searches of bibliographic databases were conducted to identify studies. Pooled effect estimates from different surgical procedures were calculated using a random-effects model.

RESULTS

Quantitative data were synthesized from 58 studies including a total of 1985 participants. Whilst 40 medications and 6 supplements were evaluated across these studies, heterogeneity and missing information reduced the scope of the meta-analysis to the following medications and supplements: atorvastatin, paracetamol, omeprazole, midazolam, vitamin D, calcium, zinc, and iron supplements. There were no significant differences in PK parameters post-surgery for the drugs atorvastatin and omeprazole, and supplements calcium, ferritin, and zinc supplements. Paracetamol showed reduced clearance (mean difference [MD] = -15.56 L/hr, p = 0.0002, I2 = 67%), increased maximal concentration (MD = 6.90 μg/ml, p = 0.006, I2 = 92%) and increased terminal elimination half-life (MD = 0.49 hr, p < 0.0001, I2 = 3%) post-surgery. The remaining 36 medications and 2 supplements were included in a systematic review. Overall, 18 of the 53 drugs and supplements showed post-operative changes in PK parameters.

CONCLUSION

This study demonstrates heterogeneity in practice and could not reach conclusive findings for most PK parameters. Prospective studies are needed to inform best practice and enhance patient healthcare and safety following bariatric surgery.

The Role of Dietary Intake in the Weight Loss Outcomes of Roux-en-Y Gastric Bypass and Sleeve Gastrectomy: A Systematic Review and Meta-analysis

The relationship between postoperative dietary intake and weight loss after bariatric surgery remains unclear. We performed a systematic review and meta-analysis of studies published between January 2000 and May 2023, reporting weight loss outcomes, and dietary intake before and after Roux-en-Y gastric bypass and sleeve gastrectomy. A total of 42 studies were included. There was no detectable difference in dietary intake between the two procedures. Roux-en-Y gastric bypass induced an average decrease in energy intake of 886 kcal/day at 12-month post-surgery; however, there was no correlation between daily energy intake and weight loss. These findings show a substantial reduction of energy intake in the first year after bariatric surgery but do not support a link between lower energy intake and greater weight loss.

[Impact of surgical treatment of morbid obesity on joint diseases]

The prevalence of obesity in the modern world is increasing. Obesity is an independent risk factor for some rheumatic diseases and also worsens their course. The presence of chronic joint disease can make it difficult for obesity to reduce activity, creating a vicious circle where joint pain makes exercise difficult and being overweight exacerbates joint pain. At the same time, there is a conditionally radical method of treating obesity - bariatric surgery (BS), which is currently used when conservative methods are ineffective. The purpose of this review is to analyze the data presented in the world literature on the impact of BS on the course of the most common rheumatic diseases. The available data show the possibility of a positive effect of BS not only on weight loss, but also on the course of a number of rheumatic diseases.

Changes in bone mineral density after bariatric surgery in patients of different ages or patients with different postoperative periods: a systematic review and meta-analysis

To assess changes in bone mineral density (BMD) following bariatric surgery (BS) in patients with different bone sites, postoperative periods and ages. Twenty-two studies were included. Femoral neck (FN) BMD decreased after surgery (MD, - 0.05 g/cm², CI - 0.10 to - 0.01, P = 0.03). Postoperative BMD decreased more in the FN and lumbar spine (LS) of patients older than 40 (FNBMD, - 0.07 g/cm², CI - 0.13 to - 0.00, P = 0.04; LSBMD, - 0.03 g/cm², CI - 0.05 to - 0.00, P = 0.02) or patients with a postoperative time of greater than 12 months (FNBMD, - 0.06 g/cm², CI - 0.12 to - 0.01, P = 0.03; LSMD, - 0.04 g/cm², CI - 0.09 to 0.01, P = 0.12); therefore, post-BS bone loss should be monitored among patients in these groups. Longer follow-ups are needed to determine whether BMD changes or stabilizes.

Skelettale Auswirkungen bariatrischer Chirurgie

Bei zunehmender Prävalenz der Adipositas sind in Deutschland ca. 54% der Bevölkerung übergewichtig oder adipös, wobei mit steigendem Übergewicht das Risiko für weitere Erkrankungen, wie z. B. Diabetes mellitus Typ 2, Herzinsuffizienz, arterielle Hypertonie u. a. stark ansteigt. Die Reduktion des Körpergewichtes ist daher aus verschiedenen Gesichtspunkten anzustreben. Viele Patientinnen und Patienten mit Adipositas haben bereits vor einer möglichen Operation einen Mangel an Vitamin D und Calcium und zeigen in Laboruntersuchungen entsprechende Defizite. Die konservative Behandlung der Adipositas aus Ernährungs-, Bewegung- und Verhaltenstherapie bildet die Basis der möglichen Therapiemaßnahmen. Bei Versagen der konservativen Behandlungsoptionen ergibt sich ab einem Body-Mass-Index (BMI) von über 40 kg/m2 die Indikation zur operativen Therapie, ab einem BMI von 50 kg/m2 besteht unter bestimmten Voraussetzungen die primäre Indikation zur Durchführung einer bariatrisch-chirurgischen Maßnahme. Zu den in Deutschland am häufigsten empfohlenen operativen Verfahren, die in der Regel laparoskopisch durchgeführt werden, gehören weiterhin die Implantation eines Magenbands, die Bildung eines Magenschlauchs (Gastric-sleeve-Resektion), die Anlage eines proximalen Roux-en-Y-Magenbypass oder eines Omega-loop-Magenbypass. Neben der angestrebten Reduktion des Übergewichtes durch ihre restriktiven wie malabsorptiven Wirkungen führen diese OP-Methoden in unterschiedlichem Ausmaß zu Veränderungen des Kalzium-Stoffwechsels u. a. mit Hypocalcämie, Vitamin-D-Defizit und Erhöhung des Serum-Parathormons, was in einem erhöhten Frakturrisiko, Veränderungen der Knochendichte und der Mikroarchitektur des Knochens münden kann. In der Nachsorge nach bariatrischen Operationen sind daher eine ausreichende Supplementierung verschiedener Vitamine, Mineralien und Spurenelemente, die regelmäßige Kontrolle der Laborparameter und der Knochendichte sowie ein angepasstes körperliches Training wichtig. Aus osteologischer Sicht kommt bei diagnostizierter Osteoporose insbesondere eine intravenöse antiresorptive Therapie in Betracht.

Effects of physical activity and dietary supplement on fat free mass and bone mass density during weight loss - a systematic review and meta-analysis

Background: After a diet- or surgery induced weight loss almost 1/3 of lost weight consists of fat free mass (FFM) if carried out without additional therapy. Exercise training and a sufficient supply of protein, calcium and vitamin D is recommended to reduce the loss of FFM. Objective: To investigate the effect of exercise training, protein, calcium, and vitamin D supplementation on the preservation of FFM during non-surgical and surgical weight loss and of the combination of all interventions together in adults with obesity. Methods: A systematic review was performed with a pairwise meta-analysis and an exploratory network meta-analysis according to the PRISMA statement. Results: Thirty studies were included in the quantitative analysis. The pairwise meta-analysis showed for Exercise Training + High Protein vs. High Protein a moderate and statistically significant effect size (SMD 0.45; 95% CI 0.04 to 0.86), for Exercise Training + High Protein vs. Exercise Training a high but statistically not significant effect size (SMD 0.91; 95% CI -0.59 to 2.41) and for Exercise Training alone vs. Control a moderate but statistically not significant effect size (SMD 0.67; 95% CI -0.25 to 1.60). In the exploratory network meta-analysis three interventions showed statistically significant effect sizes compared to Control and all of them included the treatment Exercise Training. Conclusions: Results underline the importance of exercise training and a sufficient protein intake to preserve FFM during weight loss in adults with obesity. The effect of calcium and vitamin D supplementation remains controversial and further research are needed.

Effects of exercise training and dietary supplement on fat free mass and bone mass density during weight loss - a systematic review and meta-analysis

Background: After a diet- or surgery induced weight loss almost 1/3 of lost weight consists of fat free mass (FFM) if carried out without additional therapy. Exercise training and a sufficient supply of protein, calcium and vitamin D is recommended to reduce the loss of FFM. Objective: To investigate the effect of exercise training, protein, calcium, and vitamin D supplementation on the preservation of FFM during non-surgical and surgical weight loss and of the combination of all interventions together in adults with obesity. Methods: A systematic review was performed with a pairwise meta-analysis and an exploratory network meta-analysis according to the PRISMA statement. Results: Thirty studies were included in the quantitative analysis. The pairwise meta-analysis showed for Exercise Training + High Protein vs. High Protein a moderate and statistically significant effect size (SMD 0.45; 95% CI 0.04 to 0.86), for Exercise Training + High Protein vs. Exercise Training a high but statistically not significant effect size (SMD 0.91; 95% CI -0.59 to 2.41) and for Exercise Training alone vs. Control a moderate but statistically not significant effect size (SMD 0.67; 95% CI -0.25 to 1.60). In the exploratory network meta-analysis three interventions showed statistically significant effect sizes compared to Control and all of them included the treatment Exercise Training. Conclusions: Results underline the importance of exercise training and a sufficient protein intake to preserve FFM during weight loss in adults with obesity. The effect of calcium and vitamin D supplementation remains controversial and further research are needed.

Effects of physical activity and dietary supplement on fat free mass and bone mass density during weight loss - a systematic review and meta-analysis

Background: After a diet- or surgery induced weight loss almost 1/3 of lost weight consists of fat free mass (FFM) if carried out without additional therapy. Exercise training and a sufficient supply of protein, calcium and vitamin D is recommended to reduce the loss of FFM. Objective: To investigate the effect of exercise training, protein, calcium, and vitamin D supplementation on the preservation of FFM during non-surgical and surgical weight loss and of the combination of all interventions together in adults with obesity. Methods: A systematic review was performed with a pairwise meta-analysis and an exploratory network meta-analysis according to the PRISMA statement. Results: Thirty studies were included in the quantitative analysis. The pairwise meta-analysis showed for Exercise Training + High Protein vs. High Protein a moderate and statistically significant effect size (SMD 0.45; 95% CI 0.04 to 0.86), for Exercise Training + High Protein vs. Exercise Training a high but statistically not significant effect size (SMD 0.91; 95% CI -0.59 to 2.41) and for Exercise Training alone vs. Control a moderate but statistically not significant effect size (SMD 0.67; 95% CI -0.25 to 1.60). In the exploratory network meta-analysis three interventions showed statistically significant effect sizes compared to Control and all of them included the treatment Exercise Training. Conclusions: Results underline the importance of exercise training and a sufficient protein intake to preserve FFM during weight loss in adults with obesity. The effect of calcium and vitamin D supplementation remains controversial and further research are needed.

Trends in Serum Vitamin D Levels within 12 Months after One Anastomosis Gastric Bypass (OAGB)

PURPOSE

To assess serum vitamin D trend from baseline to 12 months after one anastomosis gastric bypass (OAGB).

MATERIALS AND METHODS

In this observational cohort analysis of longitudinal data, we assessed the trend of serum vitamin D, and its associations with anthropometric, and biochemical measurements in 98 patients undergoing OAGB in a bariatric surgery center. All participants were on >800 IU/day vitamin D supplementation.

RESULTS

Vitamin D, lipid profile, creatinine, and albumin levels significantly improved at 12 months post-surgery. Vitamin D concentrations significantly increased from 26.52 ± 12.32 to 54.52 ± 27.90 ng/mL at 12 months. The correlations between vitamin D concentrations and weight, body mass index, lipid profile, ferritin, glycemic indices, and albumin were not significant. In addition, the correlations between vitamin D and parathormone, vitamin D receptor, calcium, phosphorus, body composition, and basal metabolic rate (BMR) did not reach the threshold of statistical significance at 12 months following bariatric surgery. Although there was a significant correlation between body weight and body composition (P < 0.001) and basal metabolic rate (BMR) (r = 0.762, P < 0.001) at 12 months, there were no significant correlations between weight change percent and body composition (P > 0.05), BMR (r = -0.101, P = 0.350), and vitamin D (r = 0.120, P = 0.271) at 12 months.

CONCLUSION

Our results showed that supplementation of vitamin D with dosage of >800 IU/day is sufficient for prevention of vitamin D deficiency within 12 months after OAGB surgery. Note: This data is mandatory.

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.

Recommendations for nutritional care after bariatric surgery: Recommendations for best practice and SOFFCO-MM/AFERO/SFNCM/expert consensus

Nutritional care after bariatric surgery is an issue of major importance, especially insofar as risk of deficiency has been extensively described in the literature. Subsequent to the deliberations carried out by a multidisciplinary working group, we are proposing a series of recommendations elaborated using the Delphi-HAS (official French health authority) method, which facilitates the drawing up of best practice and consensus recommendations based on the data of the literature and on expert opinion. The recommendations in this paper pertain to dietary management and physical activity, multivitamin and trace element supplementation and the prevention and treatment of specific deficiencies in vitamins B1, B9, B12, D and calcium, iron, zinc, vitamins A, E and K, dumping syndrome and reactive hypoglycemia.

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.

Hospital Readmissions for Hyperparathyroidism After Bariatric Surgery in the United States: A National Database Review

Introduction: The incidence and significance of hyperparathyroidism in patients after bariatric surgery have been established to some degree; however, the impact it has on the national healthcare system has not. We sought to assess the risk of readmission and related comorbidities in this patient population.

Methods: The Healthcare Cost and Utilization Project Nationwide Readmission Database was queried for all patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). Multivariate logistic regression analysis was conducted to identify factors associated with readmission for hyperparathyroidism.

Results: A total of 915,792 patients between 2010 and 2015 were queried; 43.2% had undergone SG and 56.8% had RYGB. A total of 589 patients were readmitted for hyperparathyroidism; 80.8% were female and 68% had a Charlson comorbidity index ≥ 2. Factors associated with readmission were as follows: age 45-64 years (odds ratio [OR] 1.42, p=0.001), Medicare (OR 3.01, p<0.001) or Medicaid (OR 2.61, p<0.001) insurance status, lower median household income, renal failure (OR 17.14, p<0.001), hypertension (OR 2.89, p<0.001), and deficiency anemia (OR 2.62, p<0.01).

Conclusions: Parathyroid axis monitoring may provide benefits to predictably high-risk patients. Appropriate surveillance may decrease the impact of bariatric hyperparathyroidism readmission on the U.S. healthcare system.

Roux-en-Y gastric bypass and gastric sleeve surgery result in long term bone loss

OBJECTIVES

Little is known about the long-term skeletal impact of bariatric procedures, particularly the increasingly commonly performed gastric sleeve surgery (GS). We examined bone density (BMD) change following three types of bariatric surgery Roux-en-Y gastric bypass (RYGB), GS and laparoscopic adjustable gastric banding (LAGB), compared with diet, over 36 months.

METHODS

Non-randomized, prospective study of participants with severe obesity (n = 52), undergoing weight-loss interventions: RYGB (n = 7), GS (n = 21), LAGB (n = 11) and diet (n = 13). Measurements of calciotropic indices, gut hormones (fasting and post prandial) peptide YY (PYY), glucagon-like peptide 1 (GLP1) and adiponectin together with dual-X-ray absorptiometry and quantitative computed tomography scans were performed thorough the study.

RESULTS

All groups lost weight during the first 12 months. Despite weight stability from 12 to 36 months and supplementation of calcium and vitamin D, there was progressive bone loss at the total hip (TH) over 36 months in RYGB -14% (95% CI: -12, -17) and GS -9% (95% CI: -7, -10). In RYGB forearm BMD also declined over 36 months -9% (95% CI: -6, -12) and LS BMD declined over the first 12 months -7% (95% CI: -3, -12). RYGB and GS groups experienced significantly greater bone loss until 36 months than LAGB and diet groups, which experienced no significant BMD loss. These bone losses remained significant after adjustment for weight loss and age. RYGB and GS procedures resulted in elevated postprandial PYY, adiponectin and bone turnover markers up to 36 months without such changes among LAGB and diet participants.

CONCLUSIONS

RYGB and GS but not LAGB resulted in ongoing TH bone loss for three postoperative years. For RYGB, bone loss was also observed at LS and non-weight-bearing forearms. These BMD changes were independent of weight and age differences. We, therefore, recommend close monitoring of bone health following RYGB and GS surgeries.

Association of Bariatric Surgery With Risk of Fracture in Patients With Severe Obesity

IMPORTANCE

Given the complex relationship between body mass index, body composition, and bone density and the correlative nature of the studies that have established the prevailing notion that higher body mass indices may be protective against osteopenia and osteoporosis and, therefore, fracture, the absolute risk of fracture in patients with severe obesity who undergo either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) compared with those who do not undergo bariatric surgery is unknown.

OBJECTIVE

To assess the rates of fractures associated with obesity and compare rates between those who do not undergo bariatric surgery, those who undergo RYGB, and those who undergo SG.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective multicenter cohort study of Medicare Standard Analytic Files derived from Medicare parts A and B records from January 2004 to December 2014, patients classified as eligible for bariatric surgery using the US Centers of Medicare & Medicaid criteria who either did not undergo bariatric surgery or underwent RYGB or SG were exactly matched in a 1:1 fashion based on their age, sex, Elixhauser Comorbidity Index, hypertension, smoking status, nonalcoholic fatty liver disease, hyperlipidemia, type 2 diabetes, osteoporosis, osteoarthritis, and obstructive sleep apnea status. Data were analyzed from November to December 2019.

EXPOSURES

RYGB or SG.

MAIN OUTCOMES AND MEASURES

The primary outcome measured in this study was the odds of fracture overall based on exposure to bariatric surgery. Secondary outcomes included the odds of type of fracture (humerus, radius or ulna, pelvis, hip, vertebrae, and total fractures) based on exposure to bariatric surgery.

RESULTS

A total of 49 113 patients were included and were equally made up of 16 371 bariatric surgery-eligible patients who did not undergo weight loss surgery, 16 371 patients who had undergone RYGB, and 16 371 patients who had undergone SG. Each group consisted of an equal number of 4109 men (25.1%) and 12 262 women (74.9%) and had an equal distribution of ages, with 11 780 patients (72.0%) 64 years or younger, 4230 (25.8%) aged 65 to 69 years, 346 (2.1%) aged 70 to 74 years, and 15 (0.1%) aged 75 to 79 years. Patients undergoing RYGB were found to have no significant difference in odds of fractures compared with bariatric surgery-eligible patients who did not undergo surgery. Patients undergoing undergone SG were found to have decreased odds of fractures of the humerus (odds ratio [OR], 0.57; 95% CI, 0.45-0.73), radius or ulna (OR, 0.38; 95% CI, 0.25-0.58), hip (OR, 0.49; 95% CI, 0.33-0.74), pelvis (OR, 0.34; 95% CI, 0.18-0.64), vertebrae (OR, 0.60; 95% CI, 0.48-0.74), or fractures in general (OR, 0.53; 95% CI, 0.46-0.62). Compared with patients undergoing SG, patients undergoing RYGB had a significantly greater risk of total fractures (OR, 1.79; 95% CI, 1.55-2.06) and humeral fractures (OR, 1.60; 95% CI, 1.24-2.07).

CONCLUSIONS AND RELEVANCE

In this cohort study, bariatric surgery was associated with a reduced risk of fracture in bariatric surgery-eligible patients. Sleeve gastrectomy might be the best option for weight loss in patients in which fractures could be a concern, as RYGB may be associated with an increased fracture risk compared with SG.

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.

Determining changes in bone metabolism after bariatric surgery in postmenopausal women

BACKGROUND

Accelerated bone loss is a known complication after bariatric surgery. Bone mineral density has been shown to decrease significantly after Laparoscopic Roux-en-Y gastric bypass (RYGB). Laparoscopic sleeve gastrectomy (SG) effects on bone density are largely unknown. This should be considered for those with increased preoperative risk for bone loss, such as postmenopausal females.

METHODS

This prospective clinical trial included postmenopausal patients, with BMI ≥ 35 k/m2, being evaluated for either RYGB or SG. Patients with history of osteoporosis, estrogen hormone replacement therapy, active smoking, glucocorticoid use, or weight > 295 lb were excluded. Patients underwent DEXA scans preoperatively and 1 year postoperatively with measurement of total body bone mineral density (BMD) and bone mineral content (BMC) as well as regional site-specific BMD and BMC.

RESULTS

A total of 28 patients were enrolled. 16 (57.1%) patients underwent RYGB and 12 (42.9%) patients underwent SG. Median preoperative BMI was 44.2 k/m2 (IQR 39.9, 46.6). Median change in BMI at 12 months was - 11.3 k/m2 (IQR - 12.8, - 7.9). A significant reduction in total body BMC was seen when comparing preoperative measurements to postoperative measurements (2358.32 vs 2280.68 grams; p = 0.002). Regional site BMC and BMD significantly decreased in the ribs and spine postoperatively (p = < 0.02) representing the greatest loss in the axial skeleton. Comparing those who underwent RYGB to SG there was no significant difference between the two groups when evaluating changes in total or regional site BMD.

CONCLUSION

Postmenopausal women were found to have decreased BMD and BMC after RYGB and SG, suggesting that high-risk women may benefit from postoperative DEXA screening. Further study is needed to determine the clinical significance of these findings. It is unknown if these changes in BMD are due to modifiable factors (Vitamin D level, activity level, hormone status, etc.), and whether BMD and BMC is recovered beyond 1 year.

Endocrine implications of bariatric surgery: a review on the intersection between incretins, bone, and sex hormones

Bariatric surgery is now the most widely used intervention for the treatment of human obesity. A large body of literature has demonstrated its efficacy in sustained weight loss and improvement in its associated comorbidities. Here, we review the effect of bariatric surgery in gut hormone physiology, bone remodeling and the reproductive axis. Rapid improvements in insulin release and sensitivity appear to be weight loss independent and occur immediately after surgery. These effects on pancreatic beta cells are mostly due to increased gut hormone secretion due to augmented nutrient delivery to the small intestine. Bone remodeling is also affected by gut hormones. Phenotypic skeletal changes observed in mice deficient in GLP-1 or GIP suggest that increased incretins may improve bone density. However, these positive effects may be counterbalanced by the association between weight loss and a reduction in bone density. Finally, studies have shown a marked improvement following bariatric surgery in infertility and PCOS in women and hypogonadism in men. Thus, the net effect on endocrine systems after bariatric surgery will likely vary on an individual basis and depend on factors such as comorbidities, peri-menopausal state, amount of weight loss, and likelihood to adhere to vitamin supplementation after surgery.

Bone Health After Bariatric Surgery

Bariatric surgery results in long-term weight loss and improvement or resolution in obesity-related comorbidities. However, mounting evidence indicates that it adversely affects bone health. This review summarizes clinical research findings about the impact of bariatric surgery on skeletal outcomes. The literature is the largest and strongest for the Roux-en-Y gastric bypass (RYGB) procedure, as RYGB was the most commonly performed bariatric procedure worldwide until it was very recently overtaken by the sleeve gastrectomy (SG). Because SG is a newer procedure, its skeletal effects have not yet been well defined. Epidemiologic studies have now demonstrated an increased risk of fracture after RYGB and biliopancreatic diversion with duodenal switch, both of which include a malabsorptive component. As these epidemiologic data have emerged, patient-oriented studies have elucidated the bone tissue-level changes that may account for the heightened skeletal fragility. Bariatric surgery induces early and dramatic increases in biochemical markers of bone turnover. A notable feature of recent patient-oriented clinical studies is the application of advanced skeletal imaging modalities; studies address the limitations of dual-energy X-ray absorptiometry (DXA) by using quantitative computed tomography (QCT)-based modalities to examine volumetric bone mineral density and compartment-specific density and microstructure. RYGB results in pronounced declines in bone mass at the axial skeleton demonstrated by DXA and QCT, as well as at the appendicular skeleton demonstrated by high-resolution peripheral quantitative computed tomography (HR-pQCT). RYGB has detrimental effects on trabecular and cortical microarchitecture and estimated bone strength. Skeletal changes after RYGB appear early and continue even after weight loss plateaus and weight stabilizes. The skeletal effects of bariatric surgery are presumably multifactorial, and mechanisms may involve nutritional factors, mechanical unloading, hormonal factors, and changes in body composition and bone marrow fat. Clinical guidelines address bone health and may mitigate the negative skeletal effects of surgery, although more research is needed to direct and support such guidelines. © 2018 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Hypocalcemia After Bariatric Surgery: Prevalence and Associated Risk Factors

BACKGROUND

The reported prevalence of hypocalcemia after bariatric surgery ranges from 1% after Roux-en-Y gastric bypass (RYGB) to 25% after bilio-pancreatic diversion-duodenal switch (BPD-DS).

OBJECTIVE

We aimed to define the prevalence of post-operative hypocalcemia and identify clinical predisposing factors.

SETTING

The study was conducted in an Academic Medical Center, USA.

METHODS

Retrospective analysis of all patients undergoing bariatric surgery from May 2008 to December 2014 at Mayo Clinic Rochester, Minnesota was performed. Patients with revision surgeries were excluded. Hypocalcemia was defined as the lowest recorded serum calcium occurring at least 2 weeks post-operatively.

RESULTS

Nine hundred ninety-nine patients fulfilled the criteria above. After correction for serum albumin concentration, 36 patients had serum calcium ≤8.9 mg/dl. Mean serum calcium was 8.1 ± 0.6 mg/dl. The prevalence was 1.9% in the RYGB group, 9.3% in the sleeve gastrectomy (SG) group, and 10% in the BPD-DS group. In all three surgical types, patients with hypocalcemia had significantly lower serum albumin and serum 25 (OH) vitamin D concentrations when compared to their normocalcemic counterparts (P < 0.01). The presence of renal insufficiency and vitamin D deficiency was associated with the highest risk of developing hypocalcemia after surgery [OR 16.8 (6.45-47.7) and 7.1(2.9-17.3), respectively]. Pre-operative renal insufficiency increased the odds of developing hypocalcemia by 20-fold.

CONCLUSIONS

In our series, hypocalcemia was identified in 3.6% of patients undergoing all bariatric surgery. Patients who are predisposed to developing post-operative hypocalcemia, such as those with pre-operative renal impairment, or post-operative vitamin D deficiency and renal insufficiency, may benefit from increased surveillance and prevention strategies.

Predictive Factors of Secondary Normocalcemic Hyperparathyroidism after Roux-en-Y Gastric Bypass

OBJECTIVE

Aim of this study is to evaluate determinants of secondary normocalcemic hyperparathyroidism (SNHPT) persistence in patients who have undergone Roux-en-Y gastric bypass on vertical-banded gastroplasty.

METHODS

226 consecutive patients submitted to bariatric surgery were prospectively enrolled and divided in two groups on the basis of preoperative presence of SNHPT. For each patient, we evaluated anthropometric and laboratory parameters. Calcium metabolism (calcemia, PTH, and 25-hydroxy vitamin D serum levels) was studied before surgery and at 6-month intervals (6, 12, and 18 months) as surgical follow-up.

RESULTS

Based on presurgical SNHPT presence or absence, we defined group 1-201 patients and group 2-25 patients, respectively. Among the group 1, 153 (76%) recovered from this endocrinopathy within 6 months after surgery (group 3), while the remaining 48 patients (24%) had persistent SNHPT (group 4). Comparing the anthropometric and laboratory data of group 3 with group 2, the only statistically significant factor was the elapsed time since a prior effective medically controlled diet that led to a steady and substantial weight loss. We found also a statistically significant difference (p < 0.05) between group 3 and group 4 in term of % of weight loss and PTH levels.

CONCLUSIONS

Patients suitable for bariatric surgery must have history of at least one efficient medically controlled diet, not dating back more than 5 years before surgery. This elapsed time represent the cut-off time within which it is possible to recover from SNHPT in the first semester after Roux-en-Y gastric bypass on vertical-banded gastroplasty. The treatment of vitamin D insufficiency and the evaluation of SNHPT before bariatric surgery should be recommended. The clinical significance of preoperative SNHPT and in particular SNHPT after bariatric surgery remains undefined and further studies are required.

Reconstruction method as an independent risk factor for postoperative bone mineral density loss in gastric cancer

BACKGROUND AND AIM

No study has compared the incidence of postoperative bone metabolic disorders between Billroth-I (B-I) and Roux-en-Y (R-Y) reconstructions after distal gastrectomy (DG) for gastric cancer (GC). In this study, we wished to examine the impact of reconstruction method on postoperative bone mineral density (BMD) loss.

METHODS

We investigated a total of 148 consecutive patients who underwent DG with B-I or R-Y reconstruction for stage I GC between 2008 and 2012. We retrospectively assessed the BMD data using computed tomography attenuation values of the first lumbar vertebra after surgery.

RESULTS

In multivariate analysis for the whole study series, R-Y reconstruction was identified as an independent risk factor for BMD loss after DG (P < 0.0001; OR = 5.60; 95% CI = 2.38-13.98). Propensity score match analysis was used to overcome bias because of the different covariates for the two groups; even though the 37 patients in the B-I group and the 37 patients in the R-Y group had no significant difference among characteristics, B-I reconstruction was validated to have superiority over R-Y reconstruction for preventing BMD loss in the first 3 years after DG. The cumulative hazard ratio of osteoporosis after gastrectomy was significantly higher in the R-Y group than in the B-I group (P = 0.0427).

CONCLUSIONS

Billroth-I reconstruction might be a preferable method for preventing BMD loss after gastrectomy in GC patients.

Is Trabecular Bone Score Valuable in Bone Microstructure Assessment after Gastric Bypass in Women with Morbid Obesity?

Introduction: The effects of bariatric surgery on skeletal health raise many concerns. Trabecular bone score (TBS) is obtained through the analysis of lumbar spine dual X-ray absorptiometry (DXA) images and allows an indirect assessment of skeletal microarchitecture (MA). The aim of our study was to evaluate the changes in bone mineral density (BMD) and alterations in bone microarchitecture assessed by TBS in morbidly obese women undergoing Roux-en-Y gastric bypass (RYGB), over a three-year follow-up. Material/Methods: A prospective study of 38 morbidly obese white women, aged 46.3 ± 8.2 years, undergoing RYGB was conducted. Biochemical analyses and DXA scans with TBS evaluation were performed before and at one year and three years after surgery. Results: Patients showed normal calcium and phosphorus plasma concentrations throughout the study. However, 25-hydroxyvitamin D (25(OH)D₃) decreased, and 71% of patients had a vitamin D deficiency at three years. BMD at femoral neck and lumbar spine (LSBMD) significantly decreased 13.53 ± 5.42% and 6.03 ± 6.79%, respectively, during the three-year follow-up; however Z-score values remained above those for women of the same age. TBS was within normal ranges at one and three years (1.431 ± 106 and 1.413 ± 85, respectively), and at the end of the study, 73.7% of patients had normal bone MA. TBS at three years correlated inversely with age (r = −0.41, p = 0.010), body fat (r = −0.465, p = 0.004) and greater body fat deposited in trunk (r = −0.48, p = 0.004), and positively with LSBMD (r = 0.433, p = 0.007), fat mass loss (r = 0.438, p = 0.007) and lean mass loss (r = 0.432, p = 0.008). In the regression analysis, TBS remained associated with body fat (β = −0.625, p = 0.031; R² = 0.47). The fracture risk, calculated by FRAX^® (University of Sheffield, Sheffield, UK), with and without adjustment by TBS, was low. Conclusion: Women undergoing RYGB in the mid-term have a preserved bone MA, assessed by TBS.

Relationship Between Bariatric Surgery and Bone Mineral Density: a Meta-analysis

BACKGROUND

A meta-analysis regarding bone loss after bariatric surgery, designed to compare surgical and nonsurgical groups, has not yet been performed. Therefore, we performed a meta-analysis to compare the differences between bariatric surgical groups and nonoperated controls with regard to bone mineral density.

METHODS

In March 2015, we performed a review of the literature using PubMed, EMBASE, and the Cochrane Library. The search focused on retrospective and prospective studies, including but not limited to randomized studies published in English.

RESULTS

Among 1299 studies that were initially screened, ten met the selection criteria. For all types of bariatric surgery, bone density at the femoral neck was lower in the surgical group than in the nonsurgical control group (mean difference [MD] -0.05 g/cm(2); 95 % confidence interval [CI], -0.07 to -0.02; p = 0.001); no difference in bone density was found between the two groups at the lumbar spine (MD -0.01 g/cm(2); 95 % CI -0.07 to 0.05; p = 0.661). The analysis of Roux-en-Y gastric bypass showed similar results.

CONCLUSION

Bone density at the femoral neck decreased after bariatric surgery, compared to that in nonsurgical controls, whereas bone density at the lumbar spine did not show a difference between groups. Further larger scale studies with comparative nonsurgical controls are warranted to overcome the heterogeneity among studies in this analysis and to add evidence of possible bone loss subsequent to bariatric surgical procedures.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Outcomes of laparoscopic sleeve gastrectomy in elderly obese Japanese patients

AIM

Laparoscopic sleeve gastrectomy (LSG) has proven to be the most effective strategy for the treatment of morbid obesity, however its efficacy and safety in an aging population has not yet been confirmed. In this study, we evaluated the effectiveness and safety of LSG in elderly obese Japanese patients.

METHODS

Three obese individuals aged >60 years and 11 obese individuals aged <60 years who underwent LSG were enrolled. Pre- and postoperative changes after at least 12 months were examined, including bodyweight, body mass index, total weight loss, excess weight loss, bone mineral density and bone-related markers.

RESULTS

There were no significant differences between patients aged <60 years and >60 years in terms of percent total weight loss (24.4 ± 11 vs 23 ± 4.4%, respectively) and percent excess weight loss (49.1 ± 23.4 vs 47.6 ± 10 %, respectively). Dual-energy X-ray absorptiometry was carried out before and 12 months after LSG. There were no significant differences in bone mineral density changes at the lumbar spine and femoral neck between the two groups (0.01 ± 0.06 vs 0.02 ± 0.03 g/cm² , -0.03 ± 0.06 vs -0.08 ± 0.02 g/cm² , respectively). There were no peri- and postoperative complications. All three patients aged >60 years had reduced bone mineral density in the femoral neck after LSG; one was diagnosed with osteoporosis.

CONCLUSIONS

Although the present results suggest that LSG could be of considerable benefit to elderly obese Japanese patients, long-term careful observation after bariatric surgery is especially important in elderly patients to prevent future osteoporosis. Geriatr Gerontol Int 2017; 17: 2068-2073.

Vitamin D alteration associated with obesity and bariatric surgery

Obesity and severe obesity constitute growing serious health problems reaching epidemic proportion in most countries. Interactions and relationships between obesity and bone tissue and its metabolism are complex but are more and more studied and recognized. Obesity is associated with an altered hormonal profile including particularly bone-regulating hormones like vitamin D. Bariatric surgery procedures, thanks to their effectiveness to achieve therapeutic endpoints for comorbidities associated with obesity, have had an increasing success. However, these surgeries by producing mechanical restriction and or malabsorption syndrome lead to nutritional deficiencies including vitamin D. In this review, we aim to (1) discuss the nutritional deficiency of vitamin D in the obese, (2) to summarize the different surgical options in bariatric surgery and to present the evidence concerning these procedures and their associated profile in vitamin D post-operative insufficiency, (3) to present the different recommendations in clinical practice to prevent or treat vitamin D deficiencies or insufficiencies in patients treated by bariatric surgery and finally to introduce emerging assumptions on the relationship between vitamin D, microbiota composition and circulating bile acids. Impact statement Obesity and severe obesity constitute growing serious health problems reaching epidemic proportion in most countries with a prevalence increasing from 6.4 in 1975 to 14.9% in 2014. This present review summarizes currently available data on vitamin D deficiencies in the obese population before and after bariatric surgery. The important evidence emerging from our evaluation confirms that obese patients are at risk of multiple nutritional deficiencies, especially vitamin D deficiency, before bariatric surgery. Our survey confirms that the precise role of the gut microbiome and its associated changes on the vitamin D metabolism after the different bariatric surgery procedures has not yet been studied. Furthermore, whether differences in the microbiota may alter the therapeutic responses to vitamin D is not known.

Effect of Gastric Bypass on Bone Mineral Density, Parathyroid Hormone and Vitamin D: 5 Years Follow-up

BACKGROUND

The aim of the present study was to see if there are longitudinal changes in bone mineral density (BMD), vitamin D or parathyroid hormone (PTH) in females 5 years after Laparoscopic Roux-en-Y Gastric Bypass (LRYGB).

METHODS

Thirty-two women with mean age 41.6 ± 9.3 years and mean body mass index (BMI) 44.5 ± 4.6 kg/m(2) were included. Preoperatively, 2 and 5 years postoperatively, BMD, weight, height, S-calcium, S-albumin, S-creatinine, S-25(OH)-vitamin D and fP-PTH were measured.

RESULTS

The mean decrease in BMI between baseline and 5 years after surgery was 29.4%. BMD of the spine and femur measured as z- and t-scores, showed a linear, statistically significant declining trend over the years. The fall in BMD of the spine and femoral neck between baseline and 5 years after surgery was 19 and 25%, respectively. The mean fP-PTH showed a significant increase over the study period (20.2 μg/L increase, 95% CI:-31.99 to -8.41). S-calcium, both free and corrected for albumin, showed a decrease between baseline and 5 years after surgery. Eight patients developed osteopenia and one osteoporosis after a 5-year follow-up.

CONCLUSION

LRYGB is an efficient method for sustained long-term body weight loss. There is, however, a concomitant decrease in BMD and S-calcium, and an increase in fP-PTH.

Changes in Bone Metabolism in Morbidly Obese Patients After Bariatric Surgery: A Meta-Analysis

BACKGROUND

The aim is to evaluate via meta-analysis bone metabolism and bone mineral density (BMD) in morbidly obese patients before and after bariatric surgery.

METHODS

We searched Medline, EMBASE, and the Cochrane Library for relevant studies published before January 2014. The following outcomes were evaluated: serum calcium, serum parathyroid hormone (PTH), serum 25-hydroxyvitamin D [25(OH)D], serum or urinary N-telopeptide (NTX), bone-specific alkaline phosphatase (BSAP), and bone mineral density (BMD).

RESULTS

Ten studies, including 344 patients, met our inclusion criteria. Results showed a significant decrease in serum calcium (MD = -0.10, 95 %CI -0.14 to -0.07, P < 0.00001) and increase in serum PTH (MD = 12.41, 95 %CI 6.51 to 18.31, P < 0.00001) but no significant difference in serum 25(OH)D (MD = 1.35, 95 %CI -1.12 to 3.83, P = 0.28) following bariatric surgery. There were significant increases in serum or urinary NTX (MD = 18.49, 95 %CI 3.33 to 33.66, P = 0.02) and BSAP (MD = 7.47, 95 %CI 0.21 to 14.72, P = 0.04) but a significant decrease in BMD (MD = -0.08, 95 %CI -0.13 to -0.04, P < 0.00001) after bariatric surgery.

CONCLUSION

BMD was significantly decreased, while bone turnover was elevated, and bone remodeling was accelerated following bariatric surgery. Basal bone metabolism should be evaluated preoperatively. To prevent secondary hyperparathyroidism and bone loss, calcium and vitamin D should be monitored closely and supplemented accordingly after the surgery.

Bariatric Surgery: What the Rheumatologist Needs to Know

A staggering 76 million adults are obese in the United States. It is known that obesity contributes to increased incidence and worse disease outcomes in many rheumatic conditions. Bariatric surgery has emerged as the most effective treatment modality for the morbidly obese, leading to substantial and sustained weight loss. The purpose of this review article is to summarize the findings of studies investigating the effect of substantial weight loss achieved through bariatric surgery on rheumatic disease and outcomes. Second, with an increasing number of patients undergoing bariatric surgery, it is important for the rheumatologist to have a basic understanding of the commonly performed bariatric procedures and to be aware of important nutritional deficiencies and medication restrictions that apply to this patient population.

Markers of Bone Metabolism in Obese Individuals Undergoing Laparoscopic Sleeve Gastrectomy

BACKGROUND

Besides its advantages, bariatric surgery implicates a risk of nutritional deficiencies, which might result in impaired bone metabolism. We assessed the effect of laparoscopic sleeve gastrectomy (LSG) on blood markers of bone metabolism in obese patients during a 3-year observation period.

METHODS

In 39 obese patients (29 women, 10 men, mean BMI 51.8 ± 6.8 kg/m(2)) undergoing LSG, we measured blood concentrations of 25-hydroxyvitamin D (25(OH)D), calcium, parathyroid hormone (PTH), bone alkaline phosphatase (BAP), and N-telopeptides crosslinks (NTx) before LSG and up to 3 years postoperatively. Vitamin D and calcium supplementations were recorded.

RESULTS

LSG caused an excess weight loss (EWL) of 54 ± 20 % after 3 years. Before surgery, we found decreased levels of 25(OH)D and calcium in 80 and 5 % of the subjects, respectively, while increased levels of PTH, BAP, and NTx were found in 39, 28, and 21 %, respectively. Mean levels of NTx and the prevalence of elevated levels of NTx increased within 2 years (p < 0.001 and p < 0.01). Neither mean blood concentrations of 25(OH)D, calcium, PTH, and BAP nor relative prevalence of deficiencies regarding these markers changed during the study period. The supplementation rates of calcium and vitamin D increased postoperatively.

CONCLUSIONS

Morbid obesity is associated with pronounced changes of markers of bone metabolism; LSG did neither aggravate nor ameliorate vitamin D metabolism within a 3-year time period, but led to increased bone resorption 2 years postoperatively. Routine supplementation of calcium and vitamin D is not likely sufficient to compensate the obesity-associated deficiencies in bone metabolism.

Changes in bone mineral density after sleeve gastrectomy or gastric bypass: relationships with variations in vitamin D, ghrelin, and adiponectin levels

BACKGROUND

A major long-term concern after gastric bypass (GBP) is the risk of osteoporosis; however, little is known about this complication in patients undergoing sleeve gastrectomy (SG).

OBJECTIVE

To evaluate changes in bone mineral density (BMD) after GBP and SG, and its relationship with changes in vitamin D, parathyroid hormone (PTH), ghrelin, and adiponectin.

METHODS

Twenty-three women undergoing GBP (BMI 42.0 ± 4.2 kg/m2; 37.3 ± 8.1 years) and 20 undergoing SG (BMI 37.3 ± 3.2 kg/m2; 34.2 ± 10.2 years) were studied before and 6 and 12 months after surgery. BMD was measured by dual-energy X-ray absorptiometry. Plasma PTH, 25-hydroxyvitamin D (25-OHD), ghrelin, and adiponectin concentrations were determined. Food as well as calcium and vitamin D supplement intake was recorded.

RESULTS

Excess weight loss (mean ± SE), adjusted by baseline excess weight, was 79.1±3.8% and 74.9 ± 4.1% 1 year after GBP and SG, respectively (p = 0.481). Significant reduction in BMD for total body (TB), lumbar spine (LS), and femoral neck (FN) was observed after GBP. In the SG group, reduction in BMD was significant only for TB. Adjusted by baseline BMD, the difference between change in BMD for GBP vs. SG was not significant for TB, LS, or FN. Percent reduction in ghrelin concentration was a main factor related to total BMD loss (GBP group) and LS BMD loss (GBP and SG groups).

CONCLUSIONS

One year after gastric bypass, bone mineral density was significantly affected, mainly at the femoral neck. Decreases in bone mineral density were more dramatic among patients who had greater baseline BMD and greater reduction in ghrelin concentrations.

Two-year changes in bone density after Roux-en-Y gastric bypass surgery

CONTEXT

Bariatric surgery is increasingly popular but may lead to metabolic bone disease.

OBJECTIVE

The objective was to determine the rate of bone loss in the 24 months after Roux-en-Y gastric bypass.

DESIGN AND SETTING

This was a prospective cohort study conducted at an academic medical center.

PARTICIPANTS

The participants were adults with severe obesity, including 30 adults undergoing gastric bypass and 20 nonsurgical controls.

OUTCOMES

We measured bone mineral density (BMD) at the lumbar spine and proximal femur by quantitative computed tomography (QCT) and dual-energy x-ray absorptiometry at 0, 12, and 24 months. BMD and bone microarchitecture were also assessed by high-resolution peripheral QCT, and estimated bone strength was calculated using microfinite element analysis.

RESULTS

Weight loss plateaued 6 months after gastric bypass but remained greater than controls at 24 months (-37 ± 3 vs -5 ± 3 kg [ mean ± SEM]; P < .001). At 24 months, BMD was 5-7% lower at the spine and 6-10% lower at the hip in subjects who underwent gastric bypass compared with nonsurgical controls, as assessed by QCT and dual-energy x-ray absorptiometry (P < .001 for all). Despite significant bone loss, average T-scores remained in the normal range 24 months after gastric bypass. Cortical and trabecular BMD and microarchitecture at the distal radius and tibia deteriorated in the gastric bypass group throughout the 24 months, such that estimated bone strength was 9% lower than controls. The decline in BMD persisted beyond the first year, with rates of bone loss exceeding controls throughout the second year at all skeletal sites. Mean serum calcium, 25(OH)-vitamin D, and PTH were maintained within the normal range in both groups.

CONCLUSIONS

Substantial bone loss occurs throughout the 24 months after gastric bypass despite weight stability in the second year. Although the benefits of gastric bypass surgery are well established, the potential for adverse effects on skeletal integrity remains an important concern.

The neuropeptide Y-ergic system: potential therapeutic target against bone loss with obesity treatments

Obesity is no longer considered to provide protection against osteoporosis. Moreover, treatments for obesity are now suspected of reducing bone mass. With the escalating incidence of obesity, combined with increases in the frequency, duration and intensity of interventions used to combat it, we face a potential increase in health burden due to osteoporotic fractures. The neuropeptide Y-ergic system offers a potential target for the prevention and anabolic treatment of bone loss in obesity, due to its dual role in the regulation of energy homeostasis and bone mass. Although the strongest stimulation of bone mass by this system appears to occur via indirect hypothalamic pathways involving Y2 receptors (one of the five types of receptors for neuropeptide Y), Y1 receptors on osteoblasts (bone-forming cells) induce direct effects to enhance bone mass. This latter pathway may offer a suitable target for anti-osteoporotic treatment while also minimizing the risk of adverse side effects.

Determinants of Secondary Hyperparathyroidism in Bariatric Patients after Roux-en-Y Gastric Bypass or Sleeve Gastrectomy: A Pilot Study

Objective. Nutritional deficiencies are common after bariatric surgery. We aimed to assess the prevalence and possible predictors of secondary hyperparathyroidism (SHPT) in bariatric patients. Methods. A total of 95 patients who had undergone Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) were assessed after a median of 3 years after surgery. Anthropometric/demographic and weight-loss parameters were compared according to the presence of SHPT, independently for men/premenopausal women and postmenopausal women. Results. SHPT was highly prevalent (men/premenopausal women, 52.1%; postmenopausal women, 31.9%). Among men/premenopausal women, multivariate analysis indicated that SHPT was predicted by (a) 25-hydroxyvitamin D levels (Exp(B) = 0.869, P-value = 0.037), independently of age, sex, smoking; (b) calcium (Exp(B) = 0.159, P-value = 0.033) and smoking, independently of age and sex; (c) magnesium (Exp(B) = 0.026, P-value = 0.046) and smoking, independently of age and sex. Among postmenopausal women, SHPT was predicted by menopausal age independently of age, smoking, and levels of 25-hydroxyvitamin D or calcium. The development of SHPT was not associated with the type of surgery. Conclusions. RYGB and SG exhibited similar effects regarding the regulation of the hypothalamus-pituitary-parathyroid axis after surgery. Vitamin D status and menopausal age appear to determine SHPT on the long term. SHPT should be sought and vigorously treated with calcium and vitamin D supplementation.

Skeletal effects of bariatric surgery: examining bone loss, potential mechanisms and clinical relevance

Bariatric surgery is the most effective therapeutic approach to morbid obesity, resulting in substantial weight loss and improved cardiometabolic profiles; however, a growing body of evidence suggests that bariatric procedures increase both skeletal fragility and the risk of related future fracture secondary to excessive bone loss. Prospective evidence shows that areal bone mineral density (BMD) assessed by dual energy X-ray absorptiometry (DXA) declines by as much as 14% in the proximal femoral regions, including the femoral neck and total hip, 12 months postoperatively. Lumbar spine areal BMD outcomes show greater 12-month postoperative variability across surgical procedures (-8 to +6%) and contrast with no change in volumetric BMD outcomes measured by quantitative computed tomography. Diminished mechanical loading, micronutrient deficiency and malabsorption, along with neurohormonal alterations, offer plausible underlying mechanisms to explain these observed post-bariatric bone changes, but most remain largely unsubstantiated in this population. Importantly, DXA-based skeletal imaging may have limited utility in accurately detecting bone change in people undergoing bariatric surgery; partly because excessive tissue overlying bone increases the variability of areal BMD outcomes. Moreover, a paucity of fracture and osteoporosis incidence data raises questions about whether marked post-bariatric surgery bone loss is clinically relevant or a functional adaptation to skeletal unloading. Future studies that use technology which is able to accurately capture the site-specific volumetric BMD and bone architectural changes that underpin bone strength in people undergoing bariatric surgery, that consider mechanical load, and that better quantify long-term fracture and osteoporosis incidence are necessary to understand the actual skeletal effects of bariatric surgery.

Effects of laparoscopic Roux-en-Y gastric bypass on bone mineral density and markers of bone turnover

BACKGROUND

Despite multiple beneficial effects of weight loss after laparoscopic Roux-en-Y gastric bypass (LRYGB), the influence on bone mineral density (BMD) remains largely unknown. Our objective was to evaluate the changes in BMD and serum/urine bone markers after LRYGB.

METHODS

Thirty-four women undergoing LRYGB were prospectively enrolled and underwent bone densitometry and serum/urine analysis preoperatively and 1 year postoperative. Changes≥.025 g/cm(2) in hip, femoral neck, and spine BMD and decreases>2% in total BMD were considered significant. Statistical analysis included paired t tests and McNemar's test.

RESULTS

Mean age was 44.6 years. Body mass index at the preoperative and 1-year postoperative intervals were 46.7 and 29.6 kg/m(2), respectively. Mean hip, femoral neck, and spine (L1-L4) BMD was 1.191 versus 1.087 g/cm(2) (P< .001), 1.105 versus 1.032 g/cm(2) (P< .001), and 1.323 versus 1.277 g/cm(2) (P< .001) at the preoperative and 1 year postoperative intervals, respectively. Mean total BMD decreased from 1.328 preoperatively to 1.251 g/cm(2) at 1 year postoperative (P<.001). The decreases in BMD were 5.8%, 6.5%, 3.5%, and 8.8% for hip, femoral neck, spine (L1-L4) and total BMD from preoperative to 1 year postoperative. The proportion of patients with low vitamin D levels decreased from 55% preoperatively to 21% at 1 year postoperative (P = .004). Elevated osteocalcin and bone alkaline phosphatase was observed in 4% and 63% (P<.001), and 14% and 41% (P = .011) of patients preoperatively and at 1 year postoperative, respectively.

CONCLUSION

BMD and bone markers changed significantly after LRYGB. Current recommendations for supplementation in post-LRYGB women may need to be reevaluated.

Interdisciplinary European guidelines on metabolic and bariatric surgery

In 2012, an expert panel composed of presidents of each of the societies, the European Chapter of the International Federation for the Surgery of Obesity (IFSO-EC), and of the European Association for the Study of Obesity (EASO), as well as of the chair of EASO Obesity Management Task Force (EASO OMTF) and other key representatives from IFSO-EC and EASO, devoted the joint Medico-Surgical Workshop of both institutions to the topic of metabolic surgery in advance of the 2013 European Congress on Obesity held in Liverpool. This meeting was prompted by the extraordinary advancement made in the field of metabolic and bariatric surgery during the past decade. It was agreed to revise and update the 2008 Interdisciplinary European Guidelines on Surgery of Severe Obesity produced by focusing in particular on the evidence gathered in relation to the effects on diabetes and the changes in the recommendations of patient eligibility criteria. The expert panel allowed the coverage of key disciplines in the comprehensive management of obesity and obesity-associated diseases, aimed specifically at updating the clinical guidelines to reflect current knowledge, expertise and evidence-based data on metabolic and bariatric surgery.

Bone metabolism after bariatric surgery

Bariatric surgery is a popular and effective treatment for severe obesity but may have negative effects on the skeleton. This review summarizes changes in bone density and bone metabolism from animal and clinical studies of bariatric surgery, with specific attention to Roux-en-Y gastric bypass (RYGB), adjustable gastric banding (AGB), and sleeve gastrectomy (SG). Skeletal imaging artifacts from obesity and weight loss are also considered. Despite challenges in bone density imaging, the preponderance of evidence suggests that bariatric surgery procedures have negative skeletal effects that persist beyond the first year of surgery, and that these effects vary by surgical type. The long-term clinical implications and current clinical recommendations are presented. Further study is required to determine mechanisms of bone loss after bariatric surgery. Although early studies focused on calcium/vitamin D metabolism and mechanical unloading of the skeleton, it seems likely that surgically induced changes in the hormonal and metabolic profile may be responsible for the skeletal phenotypes observed after bariatric surgery.

Bone loss after bariatric surgery: causes, consequences, and management

Bariatric surgery is an effective and increasingly common treatment for severe obesity and its many comorbidities. The side-effects of bariatric surgery can include detrimental effects on bone and mineral metabolism. Bone disease in patients who have had bariatric surgery is affected by preoperative abnormalities in bone and mineral metabolism related to severe obesity. Changes that arise after bariatric surgery are specific to procedure type: the most pronounced abnormalities in calciotropic hormones and bone loss are noted after procedures that result in the most malabsorption. The most consistent site for bone loss after all bariatric procedures is at the hip. There are limitations of dual-energy x-ray absorptiometry technology in this population, including artefact introduced by adipose tissue itself. Bone loss after bariatric surgery is probably multifactorial. Proposed mechanisms include skeletal unloading, abnormalities in calciotropic hormones, and changes in gut hormones. Few data for fracture risk in the bariatric population are available, and this is a crucial area for additional research. Treatment should be geared toward correction of nutritional deficiencies and study of bone mineral density in high-risk patients. We explore the skeletal response to bariatric surgery, potential mechanisms for changes, and strategies for management.