Dramatic Reversal of Derangements in Muscle Metabolism and Left Ventricular Function After Bariatric Surgery

Objective: The study objective was to define muscle metabolic and cardiovascular changes after surgical intervention in clinically severe obese patients. Methods: Obesity is a state of metabolic dysregulation that can lead to maladaptive changes in heart and skeletal muscle, including insulin resistance and heart failure. In a prospective longitudinal study, 43 consecutive patients underwent metabolic profiling, skeletal muscle biopsies, and resting echocardiograms at baseline and 3 and 9 months after bariatric surgery. Results: Body mass index decreased (mean changes, 95% confidence interval [CI]): 7.7 kg/m² (95% CI, 6.70-8.89) at 3 months and 5.6 kg/m² (95% CI, 4.45-6.80; P < .0001) at 9 months after surgery, with restoration of insulin sensitivity and decreases in plasma leptin at the same time points. Concurrent with these changes were dramatic decreases in skeletal muscle transcript levels of stearoyl coenzyme-A desaturase and pyruvate dehydrogenase kinase-4 at 3 and 9 months (P < .0001, for both) and a significant decrease in peroxisome proliferation activated receptor-α-regulated genes at 9 months. Left ventricular relaxation impairment, assessed by tissue Doppler imaging, normalized 9 months after surgery. Conclusion: Weight loss results in the reversal of systemic and muscle metabolic derangements and is accompanied by a normalization of left ventricular diastolic function.