title: Early Weight Loss Independent Effects of Sleeve Gastrectomy on Diet-Induced Cardiac Dysfunction in Obese, Wistar Rats.
abstract: Several reports suggest that bariatric surgery significantly improves cardiac function in patients with obesity cardiomyopathy. The mechanism is unknown but may be due to weight-loss independent factors. We predict that the changes in gastrointestinal anatomy after a rodent model of sleeve gastrectomy (SG) will have weight-loss independent effects on cardiac dysfunction.
  
  
  
  Cardiac dysfunction was induced by feeding a 60% kcal from fat diet to male Wistar rats for 10 weeks. Rats underwent either a SG (n = 12) or pair-fed, PF (n = 8) sham surgery. Echocardiograms were performed pre- and post-operatively at 6 and 13 weeks. Blood samples were obtained at 10 weeks post-operatively for assessment of insulin sensitivity and heart failure.
  
  
  
  Forty-four percent of SG rats had a normal ejection fraction (EF) at 13 weeks ("responders") compared to five SG rats who did not recover EF ("non-responders"). Zero percent of the PF rats normalized EF (p = 0.03). SG responders had a smaller left ventricular internal diameter in systole and end systolic volume with improved systolic function compared to SG non-responders (EF 90.7 ± 1.7 vs. 75.4 ± 3.6%, p = <0.001). At 10 weeks post-operatively, plasma glucose and B-type natriuretic peptide levels were significantly lower in SG rats compared to PF rats.
  
  
  
  A SG significantly improved systolic function in 44% of rats with diet-induced obesity and cardiac dysfunction. This improvement is related to weight-loss independent effects of the surgery on the entero-cardiac axis. These results offer a novel weight-loss independent, metabolic role for bariatric surgery as a potential treatment modality for obesity-associated cardiac dysfunction.
authors.affiliation: Department of Surgery, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA. tkindel@mcw.edu.
authors.forename: Tammy L
authors.initials: TL
authors.lastname: Kindel
authors.affiliation: Department of Surgery, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Foster
authors.affiliation: Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Goldspink
authors.affiliation: Department of Pediatrics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Kindel
authors.affiliation: Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
authors.forename: John
authors.initials: J
authors.lastname: Corbett
authors.affiliation: Department of Medicine, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Widlanksy
authors.affiliation: Department of Medicine, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Strande
mesh_terms: D000818:Animals; D059305:Diet, High-Fat; D005743:Gastrectomy / Q000379:methods*; D006331:Heart Diseases / Q000150:complications / Q000209:etiology / Q000473:pathology / Q000601:surgery*; D008297:Male; D009765:Obesity / Q000150:complications / Q000473:pathology / Q000601:surgery*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D015431:Weight Loss / Q000502:physiology*
keywords: Echocardiogram; Ejection fraction; Heart failure; Metabolic surgery; Obesity cardiomyopathy