Changes in Bone Turnover Markers after Roux-en-Y Gastric Bypass Versus Sleeve Gastrectomy: a Systematic Review and Meta-Analysis

Endocrine Dysfunction Following Bariatric Surgery: A Systematic Review of Postoperative Changes in Major Endocrine Hormones

Bariatric surgery (BS) is an effective intervention for obesity and related metabolic disorders, significantly improving metabolic health and alleviating hormonal imbalances. However, it induces complex endocrine changes that can lead to dysfunctions, impacting the somatotropic, gonadal, thyroid, pancreatic, and adrenal axes. This review highlights the dual effects of BS on the endocrine system. A comprehensive review of peer-reviewed studies using PRISMA guidelines was conducted, focusing on human research evaluating pre and postoperative endocrine parameters. Studies were selected for their relevance and quality in elucidating the endocrine consequences of BS. BS restores growth hormone secretion and improves fertility but may disrupt insulin-like growth factor-1 recovery and sex hormone balance, leading to bone loss and catabolic states. Postprandial insulin hypersecretion can result in hyperinsulinemic hypoglycemia, with impaired counter-regulatory hormone responses. Secondary hyperparathyroidism and reduced bone density highlight additional risks. Changes in thyroid hormone levels have implications for both hypothyroid and euthyroid patients. These findings underscore the interplay between improved metabolic control and potential endocrine dysfunctions. The current evidence predominantly comprises association studies that may not be of quality for safe clinical decision-making, highlighting the need for high-quality research to establish causality and refine therapeutic strategies. Bridging knowledge gaps in the mechanisms underlying these changes is crucial to optimizing BS outcomes. A holistic approach integrating preoperative screening, individualized postoperative care, and targeted therapies is essential to mitigate complications while maximizing benefits.

Bone health in adults with obesity before and after interventions to promote weight loss

Obesity and its associated comorbidities constitute a serious and growing public health burden. Fractures affect a substantial proportion of people with obesity and result from reduced bone strength relative to increased mechanical loading, together with an increased risk of falls. Factors contributing to fractures in people with obesity include adverse effects of adipose tissue on bone and muscle and, in many people, the coexistence of type 2 diabetes. Strategies to reduce weight include calorie-restricted diets, exercise, bariatric surgery, and pharmacological interventions with GLP-1 receptor agonists. However, although weight loss in people with obesity has many health benefits, it can also have adverse skeletal effects, with increased bone loss and fracture risk. Priorities for future research include the development of effective approaches to reduce fracture risk in people with obesity and the investigation of the effects of GLP-1 receptor agonists on bone loss resulting from weight reduction.

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

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

Bone mineral density in young adults 5 to 11 years after adolescent metabolic and bariatric surgery for severe obesity compared to peers

OBJECTIVE

Metabolic and bariatric surgery (MBS) is associated with decreased bone mineral density (BMD) in adults. The long-term impact of MBS during adolescence on BMD is unknown. We report bone health status 5 to 11 years after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) from the Teen-LABS study cohort.

METHODS

Between 2016 and 2022, BMD was measured by dual energy x-ray absorptiometry (DXA) in 106 young adults who had undergone MBS as adolescents. Volumetric BMD by peripheral quantitative computed tomography was measured on a subset. Ninety-one controls who had not undergone MBS were recruited for comparison.

RESULTS

In cases (RYGB: mean age 26.8 ± 1.9 years, mean BMI 42.1 ± 9.9 kg/m2, VSG: mean age 25.1 ± 2.1 years, mean BMI 37.1 ± 8.4 kg/m2), compared to controls (mean age 26.5 ± 2.7 years, mean BMI 40.2 ± 8.7 kg/m2) (age p < 0.001, BMI p = 0.02), adjusted mean DXA-BMD (g/cm2) of the RYGB (n = 58) and VSG (n = 48) groups were lower at the hip (-10.0% and -6.3%), femoral neck (-9.6% and -5.7%) and ultra-distal radius (-7.9% and -7.0%; all p < 0.001), respectively. DXA-BMD did not differ between RYGB and VSG groups. Trabecular volumetric BMD at the radius and tibia were lower in the RYGB (-30% and -26%) and VSG (-15% and -14%) groups compared to the control group (p < 0.001). Greater time since MBS was associated with lower BMD Z-scores at the hip (p = 0.05) and femoral neck (p = 0.045). Percent change in body mass index (BMI) from baseline or in the first year after MBS were not associated with bone measures at a median of 9.3 years post MBS.

CONCLUSION

BMD, especially of the hip and femoral neck, was lower in young adults who underwent MBS during adolescence compared to matched peers who had not undergone MBS. BMD Z-scores of the femoral neck were inversely associated with time since MBS but were not associated with BMI change.

Bone mineral density 5 to 11 years after metabolic and bariatric surgery in adolescents with severe obesity compared to peers

Objective

Metabolic and bariatric surgery (MBS) is associated with decreased bone mineral density (BMD) in adults. The long-term impact of MBS during adolescence on BMD is unknown. We report bone health status 5 to 11 years after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) from the Teen-LABS study cohort.

Methods

Between 2016 and 2022, BMD was measured by dual energy x-ray absorptiometry (DXA) in 106 young adults who had undergone MBS as adolescents. Volumetric BMD by peripheral quantitative computed tomography was measured on a subset. Ninety-one controls who had not undergone MBS were recruited for comparison.

Results

Compared to controls, adjusted mean DXA-BMD of the RYGB (n = 58) and VSG (n = 48) groups were lower at the hip (-10.0% and - 6.3%), femoral neck (-9.6% and - 5.7%) and ultra-distal radius (-7.9% and - 7.0%; all p < 0.001), respectively. DXA-BMD did not differ between RYGB and VSG groups. Trabecular volumetric BMD at the radius and tibia were lower in the RYGB (-30% and - 26%) and VSG (-15% and - 14%) groups compared to the control group (p < 0.001). Greater time since MBS was associated with lower BMD Z-scores at the hip (p = 0.05) and femoral neck (p = 0.045). Percent change in body mass index (BMI) from baseline or in the first year after MSB were not associated with bone measures at a median of 9.3 years post MSB.

Conclusion

BMD, especially of the hip and femoral neck, was lower in young adults who underwent MBS during adolescence compared to matched peers who had not undergone MBS. BMD Z-scores of the femoral neck decreased with time since MBS but were not associated with BMI change.