Sherman Yu

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/m(2) (95% CI, 6.70-8.89) at 3 months and 5.6 kg/m(2) (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-alpha-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.

Progressive regression of left ventricular hypertrophy two years after bariatric surgery.

BACKGROUND Obesity is a systemic disorder associated with an increase in left ventricular mass and premature death and disability from cardiovascular disease. Although bariatric surgery reverses many of the hormonal and hemodynamic derangements, the long-term collective effects on body composition and left ventricular mass have not been considered before. We hypothesized that the decrease in fat mass and lean mass after weight loss surgery is associated with a decrease in left ventricular mass. METHODS Fifteen severely obese women (mean body mass index [BMI]: 46.7+/-1.7 kg/m(2)) with medically controlled hypertension underwent bariatric surgery. Left ventricular mass and plasma markers of systemic metabolism, together with body mass index (BMI), waist and hip circumferences, body composition (fat mass and lean mass), and resting energy expenditure were measured at 0, 3, 9, 12, and 24 months. RESULTS Left ventricular mass continued to decrease linearly over the entire period of observation, while rates of weight loss, loss of lean mass, loss of fat mass, and resting energy expenditure all plateaued at 9 [corrected] months (P <.001 for all). Parameters of systemic metabolism normalized by 9 months, and showed no further change at 24 months after surgery. CONCLUSIONS Even though parameters of obesity, including BMI and body composition, plateau, the benefits of bariatric surgery on systemic metabolism and left ventricular mass are sustained. We propose that the progressive decrease of left ventricular mass after weight loss surgery is regulated by neurohumoral factors, and may contribute to improved long-term survival.

Comparison of those who succeed in losing significant excessive weight after bariatric surgery and those who fail

BackgroundGastric bypass and adjustable gastric banding currently are the most commonly performed weight loss surgeries. The results are encouraging for most patients, but some patients have a better experience than others. This report aims to define differences between those who succeeded and those that failed to lose significant excessive weight after bariatric surgery.MethodsThe authors retrospectively reviewed their database over the past 4 years. They studied 484 bariatric patients who had 1 year of follow-up evaluation. Success was defined as more than 50% excess weight loss (EWL) and failure as less than 30% EWL. Student’s t-tests were performed between the groups of bypass patients, band patients, men, women, whites, and minorities.Results An overall success rate of 58% and a failure rate of 15% were observed. The successful group was significantly younger. The starting body mass index (BMI) was significantly lower for the successful band patients. The starting excess weight was significantly less in both the successful band and bypass groups, as was the starting weight. The successful whites were significantly younger, and the starting BMI was significantly lower in the successful minority group. The unsuccessful bypass patients and whites were significantly taller than the successful group. Gender was not a significant variable in success or failure regardless of procedure.ConclusionWithout consideration for the procedure performed, the patients who successfully lost weight were younger. The unsuccessful band patients had a higher starting BMI, whereas the successful band and bypass patients had lower average starting and excess weights. The successful bypass patients were significantly shorter. Among whites, the successful patients were significantly younger and shorter. The successful minorities had a lower starting BMI. These variables give further insight into the complexity of successful excess weight loss.

Failure of adjustable gastric banding: starting BMI of 46 kg/m2 is a fulcrum of success and failure

BACKGROUND To determine the body mass index (BMI) located at the fulcrum of success and failure in a prospective study conducted at the University of Texas Health Science Center at Houston. On average, our patients whose percentage of excess weight loss (%EWL) was >50% at 1 year had a significantly lower BMI than those with <30% EWL. METHODS We prospectively collected the weight loss data for 430 patients who had had an adjustable gastric band placed. We stratified the %EWL within 1 year for patients with a BMI of 30-59 kg/m2. A line was generated for the %EWL over time for BMI groups of 30-39, 40-49, and 50-59 kg/m(2) and compared with the average %EWL over time. The y-intercepts of the resulting four lines were graphed against the average BMI for each group. RESULTS The generated y-intercept line had an R2 of .9237. Using the equation of this line and the known y-intercept for the average, we solved for x, resulting in a BMI of 46 kg/m2. Patients with a BMI <46 kg/m2 had a 50% EWL at 1 year, and those with a BMI >46 kg/m2 had only a 33% EWL at 1 year. The %EWL between the groups was significantly different at all measured intervals (P <.0001). CONCLUSION A BMI of 46 kg/m2 identifies those at high risk of failure to lose a significant percentage of excess weight after adjustable gastric banding and who require closer follow-up. Furthermore, patients who have a BMI >46 kg/m2 should be advised that their weight loss might be suboptimal at 1 year.