title: Improvement of exercise capacity and peripheral metaboreflex after bariatric surgery.
abstract: BACKGROUND
  Bariatric surgery is the only predictable method to obtain weight loss in severe obesity. Poor physical performance of obese individuals may be mediated by the peripheral metaboreflex, which controls blood flow redistribution to exercising muscles. Weight reduction improves exercise capacity through several possible mechanisms that are insufficiently understood. We hypothesized that the metaboreflex is one among the causes of improvement in exercise capacity after weight loss. This study thus aimed to examine the effect of bariatric surgery on exercise performance and metaboreflex.
  
  
  METHODS
  Severely obese patients were assessed before and 3 months after bariatric surgery. Metaboreflex was evaluated by the technique of selective induction by post-exercise circulatory occlusion (PECO+) after isometric handgrip exercise at 30% of maximum voluntary contraction. The exercise capacity was assessed by 6-min walking test.
  
  
  RESULTS
  Seventeen patients completed the protocol. Body mass index decreased from 46.4 ± 2 to 36.6 ± 2 kg/m2 (P < 0.001). The distance walked in 6 min increased from 489 ± 14 to 536 ± 14 m (P < 0.001). The peripheral metaboreflex activity, expressed by the area under the curve of vascular resistance, was lower after than before bariatric surgery (42 ± 5 to 20 ± 4 units, P = 0.003). Heart rate, blood pressure, and vascular resistance were also significantly decreased. The correlation between change in distance walked in 6 min and change in peripheral metaboreflex activity was not significant.
  
  
  CONCLUSIONS
  Weight loss after bariatric surgery increases exercise capacity and reduces peripheral metaboreflex, heart rate, and blood pressure. Further investigation on the role of metaboreflex regarding mechanisms of exercise capacity of individuals with obesity is warranted.
authors.affiliation: Graduate Program in Cardiology and Cardiological Sciences, Faculty of Medicine, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
authors.forename: Roberto P
authors.initials: RP
authors.lastname: da Silva
authors.forename: Denis
authors.initials: D
authors.lastname: Martinez
authors.forename: Christiane C
authors.initials: CC
authors.lastname: Faria
authors.forename: Luiz A
authors.initials: LA
authors.lastname: de Carli
authors.forename: Winston I B P
authors.initials: WI
authors.lastname: de Souza
authors.forename: Nelson G
authors.initials: NG
authors.lastname: Meinhardt
authors.forename: Katia E P
authors.initials: KE
authors.lastname: Souto
authors.forename: Manoel R M
authors.initials: MR
authors.lastname: Trindade
authors.forename: Jorge P
authors.initials: JP
authors.lastname: Ribeiro
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D017704:Baroreflex; D015992:Body Mass Index; D001938:Brazil / Q000453:epidemiology; D002302:Cardiac Output; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics; D006801:Humans; D008297:Male; D009043:Motor Activity; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000378:metabolism; D009767:Obesity, Morbid / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery*; D012039:Regional Blood Flow; D012891:Sleep Apnea Syndromes / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome; D015431:Weight Loss