BACKGROUND: Muscle atrophy and strength loss are common adverse outcomes following bariatric surgery. This randomized, controlled trial investigated the effects of exercise training on bariatric surgery-induced loss of muscle mass and function. Additionally, we investigated the effects of the intervention on molecular and histological mediators of muscle remodelling. METHODS: Eighty women with obesity were randomly assigned to a Roux-en-Y gastric bypass (RYGB: n = 40, age 42 +/- 8 years) or RYGB plus exercise training group (RYGB+ET: n = 40, age 38 +/- 7 years). Clinical and laboratory parameters were assessed at baseline, and 3 (POST3) and 9 months (POST9) after surgery. The 6 month, three-times-a-week, exercise intervention (resistance plus aerobic exercise) was initiated 3 months post-surgery (for RYGB+ET). A healthy, lean, age-matched control group was recruited to provide reference values for selected variables. RESULTS: Surgery resulted in a similar (p = 0.66) reduction in lower-limb muscle strength in RYGB and RYGB+ET (-26% versus -31%), which was rescued to baseline values in RYGB+ET (p = 0.21 versus baseline) but not in RYGB (p < 0.01 versus baseline). Patients in RYGB+ET had greater absolute (214 versus 120 kg, p < 0.01) and relative (2.4 versus 1.4 kg/body mass, p < 0.01) muscle strength compared with RYGB alone at POST9. Exercise resulted in better performance in timed-up-and-go (6.3 versus 7.1 s, p = 0.05) and timed-stand-test (18 versus 14 repetitions, p < 0.01) compared with RYGB. Fat-free mass was lower (POST9-PRE) after RYBG than RYGB+ET (total -7.9 versus -4.9 kg, p < 0.01; lower-limb -3.8 versus -2.7 kg, p = 0.02). Surgery reduced types I (approximately -21%; p = 0.99 between-group comparison) and II fibre cross-sectional areas (approximately -27%; p = 0.88 between-group comparison), which were rescued to baseline values in RYGB+ET (p > 0.05 versus baseline) but not RYGB (p > 0.01 versus baseline). RYGB+ET showed greater type I (5,187 versus 3,898 micro-m2, p < 0.01) and type II (5,165 versus 3,565 micro-m2, p < 0.01) fCSA than RYGB at POST9. RYGB+ET also resulted in increased capillarization (p < 0.01) and satellite cell content (p < 0.01) than RYGB at POST9. Gene-set normalized enrichment scores for the muscle transcriptome revealed that the ubiquitin-mediated proteolysis pathway was suppressed in RYGB+ET at POST9 versus PRE (NES -1.7; p < 0.01), but not in RYGB. Atrogin-1 gene expression was lower in RYGB+ET versus RYGB at POST9 (0.18 versus 0.71-fold change, p < 0.01). From both genotypic and phenotypic perspectives, the muscle of exercised patients resembled that of healthy lean individuals. CONCLUSIONS: This study provides compelling evidence-from gene to function-that strongly supports the incorporation of exercise into the recovery algorithm for bariatric patients so as to counteract the post-surgical loss of muscle mass and function.

Full text (sometimes free) may be available at these link(s):      help

• PubMed Central
• DOI
• PubMed
• PDF locator
• publisher