Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Francisco, San Francisco, California.
Diabetes Center, University of California, San Francisco, San Francisco, California.
J Clin Endocrinol Metab. 2019 Mar 1;104(3):711-720. doi: 10.1210/jc.2018-00952.
Bariatric surgery results in reduced muscle mass as weight is lost, but postoperative changes in muscle strength and performance are incompletely understood.
To examine changes in body composition, strength, physical activity, and physical performance following Roux-en-Y gastric bypass (RYGB).
DESIGN, PARTICIPANTS, OUTCOMES: In a prospective cohort of 47 adults (37 women, 10 men) aged 45 ± 12 years (mean ± SD) with body mass index (BMI) 44 ± 8 kg/m2, we measured body composition by dual-energy X-ray absorptiometry, handgrip strength, physical activity, and physical performance (chair stand time, gait speed, 400-m walk time) before and 6 and 12 months after RYGB. Relative strength was calculated as absolute handgrip strength/BMI and as absolute strength/appendicular lean mass (ALM).
Participants experienced substantial 12-month decreases in weight (-37 ± 10 kg or 30% ± 7%), fat mass (-48% ± 12%), and total lean mass (-13% ± 6%). Mean absolute strength declined by 9% ± 17% (P < 0.01). In contrast, relative strength increased by 32% ± 25% (strength/BMI) and 9% ± 20% (strength/ALM) (P < 0.01 for both). There were clinically significant postoperative improvements in all physical performance measures, including mean improvement in gait speed of >0.1 m/s (P < 0.01) and decrease in 400-m walk time of nearly a full minute.
In the setting of dramatic weight loss, lean mass and absolute grip strength declined after RYGB. However, relative muscle strength and physical function improved meaningfully and are thus noteworthy positive outcomes of gastric bypass.
减重手术后体重减轻会导致肌肉量减少，但术后肌肉力量和表现的变化尚不完全清楚。
检查 Roux-en-Y 胃旁路术（RYGB）后身体成分、力量、身体活动和身体表现的变化。
设计、参与者、结果：在一项前瞻性队列研究中，纳入了 47 名年龄 45 ± 12 岁（均值 ± 标准差）、BMI 44 ± 8 kg/m2 的成年人（37 名女性，10 名男性），我们通过双能 X 射线吸收法测量身体成分、握力、身体活动和身体表现（坐站时间、步态速度、400 米步行时间），在 RYGB 术前和术后 6 个月和 12 个月进行测量。相对力量通过绝对握力/BMI 和绝对力量/四肢瘦体重（ALM）进行计算。
参与者在 12 个月内体重（-37 ± 10 kg 或 30% ± 7%）、脂肪量（-48% ± 12%）和总瘦体重（-13% ± 6%）明显下降。平均绝对力量下降了 9% ± 17%（P < 0.01）。相比之下，相对力量增加了 32% ± 25%（力量/BMI）和 9% ± 20%（力量/ALM）（两者均 P < 0.01）。所有身体表现测量都有明显的术后改善，包括步态速度提高了 >0.1 m/s（P < 0.01），400 米步行时间减少近 1 分钟。
在体重显著减轻的情况下，RYGB 后瘦体重和绝对握力下降。然而，相对肌肉力量和身体功能显著改善，因此是胃旁路的重要积极结果。
