Endocrine Abstracts (2006) 11 P381

Effects of bariatric surgery on preclinical myocardial alterations in severe obesity and the related role of insulin resistance

A Pucci1, F Santini1, V Di Bello2, A Marsili1, P Fierabracci1, A Di Cori2, C Palagi2, MG Delle Donne2, M Giannetti1, M Anselmino3, P Vitti1, A Balbarini2 & A Pinchera1

1Department of Endocrinology and Metabolism, University Hospital of Pisa, Pisa, Italy; 2Cardiac and Thoracic Department, University Hospital of Pisa, Pisa, Italy; 3Department of General Surgery, University Hospital of Pisa, Pisa, Italy.

Obesity is a well established risk factor for congestive heart failure. The existence of an ‘obese cardiomyopathy’ has been hypothesized, as the complex combination of the effects of both hemodynamic and metabolic alterations. Aim of this study was to analyze the effect of bariatric surgery on the early myocardial alterations detected in a group of severe obese patients by high frame rate integrated backscatter (IBS). Twenty severely obese patients (5 males, 15 females, mean age 31.2±6 yr) with no history of diabetes or hypertension were enrolled. All subjects underwent conventional 2D-Color Doppler echocardiography and IBS. The homeostasis model assessment insulin resistance index (HOMA-IR) was used to assess insulin resistance. All subjects were submitted to echocardiographic and biochemical re-evaluation 6 to 24 months after surgery. The mean BMI value decreased from 47.8±8.1 to 33.0±6.0. A significant amelioration of various left ventricular myocardial functional and structural alterations was demonstrated. The main findings by conventional echocardiography were: a reduction of left atrium dimension (39.5±4.3 to 35.2±4.6 mm, P<0.0001), a reduction of left ventricular mass indexed by height (LVMh) (58.2±14.2 to 40.4±10.7 g/m2.7, P<0.0001) and an increase of E/A ratio (1.15±0.8 to 1.30±0.4, P<0.0001). The main findings by IBS were: an increase of cyclic variation index at septum level (CVIS) (16.6±5 to 27.5±11.2%, P<0.0001) and a reduction of mean ultrasonic reflectivity (IBSm) at septum level (52.8±9.5 to 46.5±8.8%, P<0.04). Significant correlations were detected between BMI variations and variations of LVMh (R=0.7, P<0.0001), CVIS (R=0.45, P<0.05) or IBSm (R=0.6, P<0.005). A highly significant association was also found between HOMA-IR variations and variations of LVMh (R=0.8, P<0.0001) or IBSm (R=0.54, P<0.05). In conclusion, weight loss achieved by bariatric surgery is followed by improvement of myocardial functional and structural alterations. These changes may be mediated by reduction of insulin resistance.