University of São Paulo: Physical exercise reverses muscle wasting in women who have had bariatric surgery
Physical exercise attenuates and reverses the loss of muscle mass, improving strength and muscle function in obese women undergoing gastrointestinal weight loss surgery (bariatric surgery). The result was obtained in a survey carried out by the Applied Physiology and Nutrition Group of the School of Physical Education and Sport (EEFE) and the Faculty of Medicine (FMUSP) at USP with 80 women who underwent surgery in São Paulo. Through molecular analysis, the study reveals that physical training benefited the body’s mechanisms that regulate muscle mass, decreasing the activity of specific genes related to protein degradation.
The findings of the work were presented in an article published in the Journal of Cachexia, Sarcopenia and Muscle last October.
Professor Hamilton Roschel, from EEFE, coordinator of the research group, explains that bariatric surgery techniques can be classified as restrictive, malabsorptive or combined. “The restrictive technique reduces the size of the stomach and, consequently, the amount of food ingested by the person”, he reports. “In malabsorptive, the path of the food is altered, inducing less traffic of food in the intestine and, therefore, less absorption of nutrients, and the combined technique combines the two methods.” According to data from the Brazilian Society of Bariatric and Metabolic Surgery (SBCBM), in 2019, 68,530 bariatric surgery procedures were performed in Brazil, a number 7% higher than the 63,969 surgeries performed in 2018.
According to the professor, bariatric surgery mitigates the severity of a series of complications associated with obesity. “For example, when compared to standard medical treatment for obesity management, that is, nutritional counseling and physical activity, monitoring of glucose levels and the use of medications to control weight, surgical intervention promotes a greater reduction in the values of the Index of Body Mass (BMI), blood sugar, resistance to the action of insulin and the use of medications in diabetic and non-diabetic obese individuals.” BMI is an index that assesses the nutritional status of the patient, calculating whether the person is within their ideal weight in relation to height.
In Brazil, according to the Federal Council of Medicine (CFM), since 2010, the criteria for the use of gastrointestinal surgery as a treatment for morbid obesity are BMI equal to or greater than 40 kg/m2, or greater than 35 kg/m2. when associated with complications such as severe sleep apnea, uncontrolled diabetes and severe cardiomyopathy. “In 2017, the CFM also recognized surgery as a therapeutic option for type 2 diabetic patients with a BMI between 30 kg/m2 and 34.9 kg/m2”, says Roschel, “provided they are aged between 30 and 70 years, resistant to treatment with oral or injectable antidiabetics, changes in lifestyle and evidence that they attended the endocrinologist for at least two years”.
“It is noteworthy that the CFM considers it essential that both the person who will undergo surgery as well as their family have a full understanding of the benefits and risks attributed to the surgical intervention”, highlights the professor. “There is always the possibility of regaining body mass, and, in the case of the combined technique, there is also the disadvantage of requiring the use of vitamin supplements for life.”
Muscle improvement
For the research, 80 patients were recruited at the Reference Center for Bariatric and Metabolic Surgery at Hospital das Clínicas (HC) of the Faculty of Medicine (FMUSP). “They were all women, aged around 40 years and an average BMI of 48 kg/m2. One group underwent a supervised physical training program three times a week for six months, starting three months after bariatric surgery, and the other received only standard post-surgical care, with medical care and nutritional monitoring, but which does not include exercise”, describes Roschel. “The training sessions included aerobic and muscle strengthening exercises, supervised by researchers from the group and conducted in our Laboratory of Assessment and Conditioning in Rheumatology (Seal) at HC.”
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“It is noteworthy that the CFM [Federal Council of Medicine] considers it essential that both the person who will undergo surgery as well as their family have a full understanding of the benefits and risks attributed to the surgical intervention”, highlights the professor. “There is always the possibility of regaining body mass and, in the case of the combined technique, there is also the disadvantage of requiring the use of vitamin supplements for life.”
In both groups, the researchers evaluated the muscle strength of the upper and lower limbs, functionality, body composition, muscle fiber area, myonuclear parameters and muscle capillarization. “The sequencing of messenger RNA (which transmits information from the DNA to the cells to synthesize proteins) and expression of genes related to the synthesis and degradation of proteins were also carried out”, adds the professor. “We observed an important reduction in muscle strength in the upper and lower limbs three months after surgery in both groups. In contrast, the trained group showed an increase in muscle strength at the end of the intervention, while the untrained group did not show any improvement.”
The trained group showed improved functionality compared to the untrained group after the intervention. “The surgery compromised the lean mass and the muscle fiber section area of both groups, however, the exercise significantly attenuated the loss of lean mass and reversed the loss at the level of the muscle fiber in the exercised group”, highlights Roschel. “Exercise improved myonuclear and capillary parameters compared to the non-exercised group and RNA sequencing revealed suppression of genes related to protein degradation.”
“Our results show that obese women undergoing surgical intervention and a physical training program acquire a profile of gene expression and muscle characteristics, that is, cross-sectional area of the muscle fiber, capillarization, strength and functionality, comparable to a control group of women with normal physical conditions”, emphasizes the professor. “These results, taken together, allow us to recommend the inclusion of systematic physical training programs in the postoperative treatment of women undergoing bariatric surgery, in order to counteract the adverse effects of muscle loss.”
The research was carried out in the Applied Physiology and Nutrition Group at EEFE and FMUSP. The work was coordinated by Professor Hamilton Roschel and had the participation of Saulo Gil, Carlos Merege-Filho, Sheyla Fellau and Bruno Gualano, researchers of the group and members of the Laboratory of Evaluation and Conditioning in Rheumatology of the Department of Rheumatology at FMUSP; Igor Murai and Rosa Pereira, from the Bone Metabolism Laboratory of the FMUSP Department of Rheumatology; Fabiana Benatti, from the Faculty of Applied Sciences at Unicamp; Ana Lúcia de Sá-Pinto and Fernanda Lima, from the Laboratory of Evaluation and Conditioning in Rheumatology, Department of Rheumatology, FMUSP; Samuel Kinjo and Walcy Teodoro, from the Department of Rheumatology at FMUSP; and Roberto de Cleva and Marco Aurélio Santo, from the Department of Digestive System Surgery at FMUSP.