Effects of Bariatric Surgery on Sarcopenic Obesity Outcomes: A One-Year Prospective Study in Middle-Aged Women

Abstract

Introduction: Sarcopenic Obesity (SO) is characterised by the confluence of muscle deterioration and high adiposity. When non-surgical interventions prove insufficient, bariatric surgery (BS) becomes the primary approach. This study aimed to address BS effects on SO outcomes one-year post-surgery among middle-aged women, also considering physical exercise's impact. Methods: Prospective single-centre study of 140 patients who underwent Roux-en-Y Gastric Bypass or Sleeve Gastrectomy between November/2019 and December/2022. Participants were categorised into tertiles according to SO's diagnosis and severity (group 1-patients with the most severe SO; group 2-intermediate; group 3-the least severe or without SO), calculated considering the consensus issued by ESPEN and EASO in 2022. Evaluations of clinical and biochemical parameters were conducted before and 12 months after BS, and the variation was used for comparative purposes. Body composition was assessed using bone density scans. Linear regression analysis accounted for both surgery type and baseline body mass index (BMI). Results: Before BS, SO prevalence in the overall sample was 89.3%, decreasing to 2.9% after BS. Group 1 had more body fat mass (56.9 vs 54.8 vs 50.7 kg, p<0.001), total, trunk and leg fat at baseline and a significantly lower total skeletal muscle mass (47.2 vs 49.4 vs 51.8 kg, p<0.001). One-year post-BS, group 1 presented more weight loss (-39.8 ± 11.4 kg, p=0.031), BMI reduction (-15.9 ± 4.6 kg/m2, p=0.005) and lost more fat mass (-32.6 vs -30.5 vs -27.9 kg, p=0.005), but not total skeletal muscle mass (-5.8 vs -5.9 vs -6.8 kg, p=0.130). Remission rates for comorbidities were substantial among all groups, but more marked among patients within group 1 (type 2 diabetes mellitus 75%, hypertension 47.1%, and dyslipidemia 52.8%). Engagement in physical exercise of any kind has increased post-BS (33.1% vs 79.1%). Conclusion: Despite concerns about malabsorptive mechanisms potentially worsening muscle loss, patients with the most severe SO undergoing BS lost more fat mass while experiencing the smallest reduction in total skeletal muscle mass. Remission rates for comorbidities following BS were notable among all groups. Key Points: Bariatric surgery emerges as both a risk factor and a management approach in sarcopenic obesity; Patients with severe sarcopenic obesity lost more fat mass and less muscle mass after bariatric surgery; Bariatric surgery reduces sarcopenic obesity's prevalence and improves comorbidities. Keywords: Bariatric surgery; Sarcopenic obesity; Metabolic outcomes; Muscle mass; Weight loss; Physical exercise.