Gastric bypass surgery improves muscle strength in obese people

USA: Gastric bypass surgery performed on obese people improves relative physical performance and muscle strength in them, according to a new study published in the Journal of Clinical Endocrinology & Metabolism.

Bariatric surgery helps obese people to lose weight and improve their overall health. Gastric bypass, one of the most common types of bariatric surgeries, is a procedure that reduces the size of the stomach, causes hormonal changes, and can lower the amount of nutrients that are absorbed from food. In this surgery, the digestive tract is rerouted, bypassing the majority of large stomach and part of the small intestine. The procedure can improve or eliminate related conditions such as diabetes. It results in reduced muscle mass as weight is lost, but postoperative changes in muscle strength and performance are incompletely understood.

Diana Alba, Diabetes Center, University of California, San Francisco, CA, USA, and colleagues conducted the study to examine changes in body composition, strength, physical activity, and physical performance 12 months following Roux-en-Y gastric bypass (RYGB).

In the prospective cohort study, researchers examined the body composition, handgrip strength, physical activity and physical performance of 47 obese adults before and six and 12 months after gastric bypass surgery. They found that dramatic weight loss causes a decline in a person's lean mass and absolute grip strength after surgery. However, relative muscle strength, walking speed and other measures of physical function improved meaningfully in these patients.

Also Read: Gastric bypass surgery better than lifestyle modification in control for diabetes and obesity

Key Findings:

• Participants experienced substantial 12-month decreases in total body weight (-37 ± 10 kg or 30 ± 7%), fat mass (-48 ± 12% of baseline), and total lean mass (-13 ± 6%).


• Mean absolute grip strength declined by 9 ± 17%. In contrast, relative muscle strength increased by 32 ± 25% (strength/BMI) and 9 ± 20% (strength/ALM).


• There were statistically and clinically significant postoperative improvements in all physical performance measures, including mean improvement in gait speed of >0.1 m/s, and a decrease in 400-m walk time of nearly a full minute (from 5.3 ± 0.7 to 4.4 ± 0.7 min).

Also Read: Long-term weight loss better with RY gastric bypass than sleeve gastrectomy

"Our research found while Roux-en-Y bariatric surgery patients are likely to see the maximum amount of strength they can exert decline as they lose weight, they actually see an increase in their relative strength--a measure of strength relative to their size," said Alba. "Our participants' physical performance also improved following surgery. The findings suggest that postoperative loss of muscle mass and absolute strength may not be a meaningful problem."

"Having good muscle strength and physical function is essential to helping people carry out their day-to-day lives," Alba said.

For further reference log on to https://doi.org/10.1210/jc.2018-00952