Musculoskeletal effects of obesity and bariatric surgery – a narrative review

A multifaceted and inclusive methodology for the detection of sarcopenia in patients undergoing bariatric surgery: an in-depth analysis of current evidence

Bariatric surgery is widely recognized as the most effective intervention for obesity and offers benefits beyond weight loss. However, not all patients achieve satisfactory weight loss, balanced changes in body composition, and resolution of comorbidities. Therefore, thorough pre- and postoperative evaluations are important to predict success and minimize adverse effects. More comprehensive assessments require broadening the focus beyond body weight and fat measurements to consider quantitative and qualitative evaluations of muscles. Introducing the concept of sarcopenia is useful for assessing the degradative and pathological changes in muscles associated with cardiometabolic function, physical performance, and other obesity-related comorbidities in patients undergoing bariatric surgery. However, there is currently no consensus or definition regarding the research and clinical use of sarcopenia in patients undergoing bariatric surgery. Therefore, this review aimed to define the concept of sarcopenia applicable to patients undergoing bariatric surgery, based on the consensus reached for sarcopenia in the general population. We also discuss the methods and significance of measuring muscle mass, quality, and strength, which are key variables requiring a comprehensive assessment.

Prevalence of Morphometric Vertebral Fractures After Bariatric Surgery and Its Relationship with Bone Mineral Density and Bone Markers

BACKGROUND

Bariatric surgery (BS) can lead to bone loss and an increased fracture risk.

METHODS

To determine the morphometric vertebral fracture (MVF) prevalence, and its relationship with bone mineral density (BMD), and biomarker's turnover after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), we analyzed post-surgery X-rays of the spine in 80 patients (88% female, 51% RYGB, age 41.2 [6.8] years) from 117 participants' retrospective cohort (1-2 years, >2 and <5 years, and >5 years). We still analyzed body composition and BMD by dual-energy X-ray absorptiometry and bone parameters.

RESULTS

MVF prevalence was 17.5% (14/80), with no statistical difference between groups (p = 0.210). RYGB group had a higher prevalence of secondary hyperparathyroidism (SHPT) (PTH ≥ 65 pg/ml; 18.4% vs 7.8%, respectively, p = 0.04), PTH (61.3 vs 49.5 pg/ml, p = 0.001), CTX (0.766 [0.29] ng/ml vs 0.453 [0.30] ng/ml, p = 0.037), and AP (101.3 [62.4] U/L vs 123.9 [60.9] U/L, p = 0.027) than the SG group. Up to 5 years postoperatively, RYGB had a lower total (1.200 [0.087] vs 1.236 [0.100] g/cm2, p = 0.02), femoral neck (1.034 [0.110] vs 1.267 [0.105], p = 0.005), and total femur BMD (1.256 [0.155] vs 1.323 [0.167], p = 0.002) than SG group. We found no statistically significant difference between the MFV (+) and MVF (-) groups regarding age, sex, BMI, surgery time, BMD, or bone and metabolic parameters, including leptin.

CONCLUSION

We found a high prevalence of MVF after BS with no differences between RYGB and SG.

Nutritional Considerations for Patients With Renal Failure Undergoing Sleeve Gastrectomy

Obesity is highly prevalent in patients with renal disease, as it contributes to or accelerates the progression of kidney disease and is frequently a barrier to kidney transplantation. Patients with renal disease have unique dietary needs due to various metabolic disturbances resulting from altered processing and clearance of nutrients. They also frequently present with physical disability, resulting in difficulty achieving adequate weight loss through lifestyle modifications. Therefore, kidney transplant candidates may benefit from bariatric surgery, particularly sleeve gastrectomy (SG), as the safest, most effective, and long-lasting weight loss option to improve comorbidities and access to transplantation. However, concerns regarding nutritional risks prevent broader dissemination of SG in this population. No specific guidelines tailored to the nutritional needs of patients with renal disease undergoing SG have been developed. Moreover, appropriate monitoring strategies and interventions for muscle loss and functional status preservation, a major concern in this at-risk population, are unknown. We aimed to summarize the available literature on the nutritional requirements of patients with renal disease seeking SG as a bridge to transplantation. We also provide insight and guidance into the nutritional management pre and post-SG.

Nutrient regulation of bone marrow adipose tissue: skeletal implications of weight loss

Adipose tissue is a dynamic component of the bone marrow, regulating skeletal remodelling and secreting paracrine and endocrine factors that can affect haematopoiesis, as well as potentially nourishing the bone marrow during periods of stress. Bone marrow adipose tissue is regulated by multiple factors, but particularly nutrient status. In this Review, we examine how bone marrow adipocytes originate, their function in normal and pathological states and how bone marrow adipose tissue modulates whole-body homoeostasis through actions on bone cells, haematopoietic stem cells and extra-medullary adipocytes during nutritional challenges. We focus on both rodent models and human studies to help understand the unique marrow adipocyte, its response to the external nutrient environment and its effects on the skeleton. We finish by addressing some critical questions that to date remain unanswered.