A Dark Side of Bariatric Surgery: The Influence of Surgery on Osteopenia and Sarcopenia
DOI:
https://doi.org/10.34635/rpc.1153Keywords:
Bariatric Surgery, Bone Diseases, Metabolic, Postoperative Complications, SarcopeniaAbstract
Introduction: Bariatric and metabolic surgery is effective for weight reduction but may induce substantial declines in skeletal muscle and bone mineral content, increasing the risk for sarcopenia and osteopenia. We aimed to study longitudinal changes in anthropometry, body composition, muscle strength, and bone mineral parameters after MBS, and to identify eventual predictors of postoperative sarcopenia and osteopenia, 18 months after surgery.
Methods: Adults undergoing BMS were evaluated at baseline and 1, 6, 12, and 18 months. Dual-energy X-ray absorptiometry (DEXA) measured fat mass, lean mass, appendicular skeletal muscle mass (ASMM), bone mineral content (BMC), and bone mineral density (BMD). Handgrip strength and biochemical markers (PTH, vitamin D, leptin, ghrelin, NRI) were also evaluated. Regression models identified predictors of sarcopenia and osteopenia.
Results: Body weight decreased from 112.4±17.5kg112.4±17.5kg to 72.5±10.9kg72.5±10.9kg at 18 months (p<0.001)(p<0.001). Significant reductions occurred in lean mass (56.5±10.1÷37.5±7.9kg;p<0.001)(56.5±10.1÷37.5±7.9kg;p<0.001)and ASMM (23.9±4.7÷15.4±4.3kg;p<0.001)(23.9±4.7÷15.4±4.3kg;p<0.001). Handgrip strength partially recovered after an early decline but did not return to baseline. BMC decreased steadily (2459±426÷2022±365g;p<0.001)(2459±426÷2022±365g;p<0.001) with declines in T-score (0.47→−0.30;p=0.012)(0.47→−0.30;p=0.012). Muscle-related indices (ASMM, ASMMI, ASMM/BMI) were the strongest predictors of both sarcopenia and osteopenia (r2(r2up to 0.562; p<0.001)p<0.001). Vitamin D, PTH, leptin, and ghrelin were not significant predictors.
Conclusion: MBS may lead to substantial muscle and bone mineral losses, with ASMM-based indices emerging as key predictors of postoperative sarcopenia and osteopenia. Early interventions, targeting muscle preservation, are essential in postoperative management.
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References
Busetto L, Dicker D, Fruhbeck G, Halford JCG, Sbraccia P, Yumuk V, et al. A new framework for the diagnosis, staging and management of obesity in adults. Nat Med. 2024;30:2395-9. doi:10.1038/S41591-024-03095-3
Blüher M. An overview of obesity-related complications: The epidemiological evidence linking body weight and other markers of obesity to adverse health outcomes. Diabetes Obes Metab. 2025;27:3. doi:10.1111/DOM.16263
Rubino F, Cummings DE, Eckel RH, Cohen RV, Wilding JP, Brown WA, et al. Definition and diagnostic criteria of clinical obesity. Lancet Diabetes Endocrinol. 2025;13:221-62. doi:10.1016/S2213-8587(24)00316-4
2022 ASMBS and IFSO: Indications for Metabolic and Bariatric Surgery | American Society for Metabolic and Bariatric Surgery. [Accessed November 21, 2022]. Available at: https://asms.org/resources/2022-asms-and-ifso-indications-for-metabolic-and-bariatric-surgery
Mendes C, Carvalho M, Bravo J, Martins S, Raimundo A. How Weight Loss After Bariatric Surgery Affects Sarcopenia Parameters and Diagnosis. Surgeries 2025;6:31. doi:10.3390/SURGERIES6020031
Cardoso P, Santos T V, Ramon-Krauel M, Pais S, De Sousa-Coelho AL. Impact of Bariatric and Metabolic Surgery on Sarcopenia-Related Parameters According to the EWGSOP2 Consensus Criteria in
Cruz-Jentoft AJ, Bahat G, Bauer J, Boirie Y, Bruyere O, Cederholm T, et al. Sarcopenia: revised European consensus on definition and diagnosis. Age Ageing. 2019;48:16-31. doi:10.1093/AGEING/AFY169
Gomes Reis M, Ivo Campos P, Adrielle Lima Vieira R, et al. Prevalence of sarcopenia after bariatric surgery: a systematic review and meta-analysis. Interdisciplinary J Ciencias Med. 2024;8:100-111. doi:10.61910/RICM.V812.436
Abiri B, Valizadeh M, Seifi Z, Amini S, Haidari F. The role of nutritional factors in fat-free mass preservation and body composition changes after bariatric surgery: a systematic review of the available evidence. Eating Weight Disord. 2025;30. doi:10.1007/s40519-025-01761-0
Chang SH, Stoll CRT, Song J, Varela JE, Eagon CJ, Colditz GA. The effectiveness and risks of bariatric surgery: an updated systematic review and meta-analysis, 2003-2012. JAMA Surg. 2014;149:275-87. doi:10.1001/JAMASURG.2013.3654
Mele C, Caputo M, Ferrero A, Daffara T, Cavigiolo B, Spadaccini D, et al. Bone Response to Weight Loss Following Bariatric Surgery. Front Endocrinol. 2022;13:921353. doi:10.3389/FENDO.2022.921353
Diniz-Sousa F, Veras L, Boppre G, Devezas V, Santos-Sousa H, Preto J, et al. The effect of bariatric surgery on gravitational loading and its impact on bone mass. Bone. 2021;153:116153. doi: 10.1016/j.bone.2021.116153.
Ben-Porat T, Elazary R, Sherf-Dagan S, Goldenshluger A, Brodie R, Mintz Y, et al. Bone Health following Bariatric Surgery: Implications for Management Strategies to Attenuate Bone Loss. Adv Nutr. 2018;9:114-27. doi:10.1093/advances/nmx024.
Vassilev G, Galata C, Finze A, Weiss C, Otto M, Reissfelder C, et al. Sarcopenia after Roux-en-Y Gastric Bypass: Detection by Skeletal Muscle Mass Index vs. Bioelectrical Impedance Analysis. J Clin Med. 2022;11:1468. doi:10.3390/JCM11061468
Nuijten MA, Eijsvoegels TM, Monpellier VM, Janssen IM, Hazebroek EJ, Hopman MT. The magnitude and progress of lean body mass, fat-free mass, and skeletal muscle mass loss following bariatric surgery: A systematic review and meta-analysis. Obes Rev. 2022;23:e13370. doi:10.1111/OBR.13370
Crispim Carvalho NN, Martins VJ, Filho JM, de Arruda Neta A, Pimenta FC, de Brito Alves JL. Effects of preoperative sarcopenia-related parameters on the musculoskeletal and metabolic outcomes after bariatric surgery: a one-year longitudinal study in females. Sci Rep. 2023;13. doi:10.1038/S41598-023-40681-W
Voican CS, Lebrun A, Maitre S, Lainas P, Lamouri K, Njike-Nakseu M, et al. Predictive score of sarcopenia occurrence one year after bariatric surgery in severely obese patients. PLoS One. 2018;13:e0197248. doi:10.1371/JOURNAL.PONE.0197248
Ionut V, Burch M, Youdim A, Bergman RN. Gastrointestinal Hormones and Bariatric Surgery-induced Weight Loss. Obesity. 2013;21:1093. doi:10.1002/OBY.20364
Balaguera-Cortes L, Wallman KE, Fairchild TJ, Guelfi KJ. Energy intake and appetite-related hormones following acute aerobic and resistance exercise. Appl Physiol Nutr Metab. 2011;36:958-66. doi:10.1139/H11-121
Kruljac I, Mirošević G, Kirigin LS, Nikolić M, Ljubičić N, Budimir I, et al. Changes in metabolic hormones after bariatric surgery and their predictive impact on weight loss. Clin Endocrinol. 2016;85:852-60. doi:10.1111/CEN.13160
Marceca GP, Londhe P, Calore F. Management of Cancer Cachexia: Attempting to Develop New Pharmacological Agents for New Effective Therapeutic Options. Front Oncol. 2020;10:298. doi:10.3389/FONC.2020.00298
Slart RH, Punda M, Ali DS, Bazzocchi A, Bock O, Camacho P, et al. Updated practice guideline for dual-energy X-ray absorptiometry (DXA). Eur J Nucl Med Mol Imaging. 2025;52:539-63. doi:10.1007/s00259-024-06912-6.
Morais T, Pereira SS, Andrade S, Neves D, Guimarães M, Nora M, et al. GLP-1 Increases Circulating Leptin Levels in Truncal Vagotomized Rats. Biomedicines. 2023;11:1322. doi:10.3390/BIOMEDICINES11051322/ S1
Casimiro I, Sam S, Brady MJ. Endocrine implications of bariatric surgery: a review on the intersection between incretins, bone, and sex hormones. Physiol Rep. 2019;7:e14111. doi:10.14814/PHY2.14111
Tsouristakis AI, Febres G, McMahon DJ, Tchang B, Conwell IM, Tsang AJ, et al. Long-Term Modulation of Appetitive Hormones and Sweet Cravings After Adjustable Gastric Banding and Roux-en-Y Gastric Bypass. Obes Surg. 2019;29:3698-705. doi:10.1007/S11695-019-04111-Z
El Ansari W, Elhag W. Weight Regain and Insufficient Weight Loss After Bariatric Surgery: Definitions, Prevalence, Mechanisms, Predictors, Prevention and Management Strategies, and Knowledge Gaps- a Scoping Review. Obes Surg. 2021;31:1755-66. doi:10.1007/S11695-020-05160-5
Otto M, Kautt S, Kremer M, Kienle P, Post S, Hasenberg T. Handgrip strength as a predictor for post bariatric body composition. Obes Surg. 2014;24:2082-8. doi:10.1007/S11695-014-1299-6
Mendes C, Carvalho M, Bravo J, Martins S, Raimundo A. The impact of bariatric surgery and exercise on systemic immune inflammation index in patients with sarcopenia obesity. Scientific Reports 2025 15:1. 2025;15(1):1-11. doi:10.1038/s41598-025-89806-3
Mendes C, Carvalho M, Cabo CA, Bravo J, Martins S, Raimundo A. Effect of a 16-Week Exercise Program After Bariatric Surgery on Sarcopenia Parameters Based on FNIH, EWGSOP2, and EASO/ESPEN Criteria: the Results of the EXPOBAR Randomized Trial Program. Obes Surg. 2025;35:3553-68. doi:10.1007/S11695-025-08142-7
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