Lean Mass Loss and Altered Muscular Aerobic Capacity after Bariatric Surgery

Abstract

<b><i>Introduction:</i></b> Patients undergoing weight loss surgery do not improve their aerobic capacity or peak oxygen uptake (VO<sub>2</sub>peak) after bariatric surgery and some still complain about asthenia and/or breathlessness. We investigated the hypothesis that a post-surgery muscular limitation could impact the ventilatory response to exercise by evaluating the post-surgery changes in muscle mass, strength, and muscular aerobic capacity, measured by the first ventilatory threshold (VT). <b><i>Methods:</i></b> Thirteen patients with obesity were referred to our university exercise laboratory before and 6 months after bariatric surgery and were matched by sex, age, and height to healthy subjects with normal weight. All subjects underwent a clinical examination, blood sampling, and body composition assessment by dual-energy X-ray absorptiometry, respiratory and limb muscle strength assessments, and cardiopulmonary exercise testing on a cyclo-ergometer. <b><i>Results:</i></b> Bariatric surgery resulted in a loss of 34% fat mass, 43% visceral adipose tissue, and 12% lean mass (LM) (<i>p</i> < 0.001). Absolute handgrip, quadriceps, or respiratory muscle strength remained unaffected, while quadriceps/handgrip strength relative to LM increased (<i>p</i> < 0.05). Absolute VO<sub>2</sub>peak or VO<sub>2</sub>peak/LM did not improve and the first VT was decreased after surgery (1.4 ± 0.3 vs. 1.1 ± 0.4 L min<sup>−1</sup>, <i>p</i> < 0.05) and correlated to the exercising LM (LM legs) (<i>R</i> = 0.84, <i>p</i> < 0.001). <b><i>Conclusions:</i></b> Although bariatric surgery has numerous beneficial effects, absolute VO<sub>2</sub>peak does not improve and the weight loss-induced LM reduction is associated to an altered muscular aerobic capacity, as reflected by an early VT triggering early exercise hyperventilation.

Body Composition Changes in Adolescents Who Underwent Bariatric Surgery: A Systematic Review and Meta-analysis

“…Despite these benefits, the surgery associated energy deprivation also leads to significant decreases in muscle mass. This might negatively affect whole-body metabolism such as aerobic capacity [ 62 ], regulation of resting metabolic rate, and possible lead to long-term musculoskeletal issues [ 63 ]. Of note, muscle mass losses in adolescents have been associated with an increased risk of metabolic syndrome [ 64 ] and nonalcoholic fatty liver disease development [ 65 ].…”

Reframing the need for exercise therapy in the clinical management of people living with obesity

“…Weight loss predicts lean mass loss 22 . Where patients lose substantial weight such as post bariatric surgery or in response to anti‐obesity medication, lean mass loss may go on to negatively impact upon function 23–25 . Furthermore lean mass loss may increase the likelihood of weight regain 26 .…”

“…22 Where patients lose substantial weight such as post bariatric surgery or in response to anti-obesity medication, lean mass loss may go on to negatively impact upon function. [23][24][25] Furthermore lean mass loss may increase the likelihood of weight regain. 26 While exercise does not significantly enhance weight loss, evidence shows aerobic exercise and higher levels of physical activity are therapeutically relevant to positively influence weight loss maintenance.…”

Effects of Preoperative Sarcopenia-Related Parameters on Cardiac Autonomic Function in Women with Obesity Following Bariatric Surgery: A One-Year Prospective Study

“…Although previous studies have demonstrated low HRV in obesity and sarcopenia [ 4 , 5 , 6 , 7 ] and that bariatric surgery (BS) reduced blood pressure (BP) and cardiac autonomic dysfunction in patients with obesity [ 14 , 15 , 16 , 17 ], there are no data in the literature evaluating the impact of BS on cardiac autonomic modulation in individuals with parameters related to sarcopenia. Considering the probable loss of muscle mass after BS [ 18 ] and that irisin, a myokine that acts in neurons in the nucleus as ambiguous promoting bradycardia, is produced by skeletal muscle, it is reasonable to infer that the benefits of BS on the cardiac autonomic system might be attenuated in individuals with low muscle mass and strength. [ 19 ].…”