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Mohamed F Algahim,
Thomas R Lux, Joshua G Leichman,
Anthony F Boyer,
Charles C Miller,
Susan T Laing,
Erik B Wilson,
Terry Scarborough,
Sherman Yu,
Brad Snyder,
Carol Wolin-Riklin,
Ursula G Kyle,
Heinrich Taegtmeyer
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ABSTRACT: 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.
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.
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.
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.
The American journal of medicine 06/2010; 123(6):549-55. · 4.47 Impact Factor
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Journal of the American College of Cardiology 04/2010; 55(16):1754; author reply 1754. · 14.16 Impact Factor
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ABSTRACT: Bariatric surgery reverses obesity-related comorbidities, including type 2 diabetes mellitus. Several studies have already described differences in anthropometrics and body composition in patients undergoing Roux-en-Y gastric bypass compared with laparoscopic adjustable gastric banding, but the role of adipokines in the outcomes after the different types of surgery is not known. Differences in weight loss and reversal of insulin resistance exist between the 2 groups and correlate with changes in adipokines.
Fifteen severely obese women (mean body mass index [BMI]: 46.7 kg/m(2)) underwent 2 types of laparoscopic weight loss surgery (Roux-en-Y gastric bypass=10, adjustable gastric banding=5). Weight, waist and hip circumference, body composition, plasma metabolic markers, and lipids were measured at set intervals during a 24-month period after surgery.
At 24 months, patients who underwent Roux-en-Y were overweight (BMI 29.7 kg/m(2)), whereas patients who underwent gastric banding remained obese (BMI 36.3 kg/m(2)). Patients who underwent Roux-en-Y lost significantly more fat mass than patients who underwent gastric banding (mean difference 16.8 kg, P<.05). Likewise, leptin levels were lower in the patients who underwent Roux-en-Y (P=.003), and levels correlated with weight loss, loss of fat mass, insulin levels, and Homeostasis Model of Assessment 2. Adiponectin correlated with insulin levels and Homeostasis Model of Assessment 2 (r=-0.653, P=.04 and r=-0.674, P=.032, respectively) in the patients who underwent Roux-en-Y at 24 months.
After 2 years, weight loss and normalization of metabolic parameters were less pronounced in patients who underwent gastric banding compared with patients who underwent Roux-en-Y gastric bypass. Our findings require confirmation in a prospective randomized trial.
The American journal of medicine 05/2009; 122(5):435-42. · 4.47 Impact Factor
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ABSTRACT: The study objective was to define muscle metabolic and cardiovascular changes after surgical intervention in clinically severe obese patients.
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.
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.
Weight loss results in the reversal of systemic and muscle metabolic derangements and is accompanied by a normalization of left ventricular diastolic function.
The American journal of medicine 11/2008; 121(11):966-73. · 4.47 Impact Factor
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Critical Care Medicine 01/2007; 34(12):3042-3. · 6.33 Impact Factor
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ABSTRACT: Obesity is an important contributor to many cardiovascular risk factors and has been associated with abnormalities in cardiac contractile function. Causes of impaired contractile function are not fully understood and may include an oversupply of substrates.
We tested the hypothesis that metabolic dysregulation may adversely influence cardiac function. Specifically, we examined the effects of plasma free fatty acids and insulin sensitivity on left ventricular function in patients with clinically severe obesity.
We measured metabolic and cardiac variables in 64 obese patients [body mass index (BMI; in kg/m(2)) > 35], including 2-D complete echocardiogram with M-mode and tissue Doppler imaging, anthropometric measurements, and analysis of blood chemistries.
The median (25th and 75th percentile) age and BMI were 46 y (36, 53 y) and 51.5 (42.5, 56.5), respectively. The prevalence of diabetes, hypertension, and insulin resistance were 38%, 53%, and 90%, respectively. Plasma free fatty acid (FFA) concentrations were elevated in the cohort. No association was observed between insulin sensitivity or anthropometric measurements and left ventricular contractile function. However, FFA concentration was independently associated with diastolic function (r = -0.33, P = 0.01), and 40% of the cohort showed age-adjusted diastolic impairment as measured by tissue Doppler imaging.
The negative association between FFA and diastolic function, in the setting of insulin resistance, suggests that excess FFA may exert a lipotoxic effect on the heart.
American Journal of Clinical Nutrition 08/2006; 84(2):336-41. · 6.67 Impact Factor
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ABSTRACT: Several lines of evidence have suggested a link between obesity and heart failure, including chronic inflammation, increased sympathetic tone, and insulin resistance. The goal of this study was to evaluate the changes in systemic metabolism, anthropometrics, and left ventricular (LV) contraction, as well as geometry, in clinically severe obese women after bariatric surgery.
Enrollment was offered consecutively to 22 women with clinically severe obesity. Participants underwent abdominal magnetic resonance imaging to quantify the visceral adipose tissue (VAT) area and tissue Doppler imaging echocardiography to measure the LV contractile function. Fasting blood chemistries were drawn to measure inflammatory markers and to calculate insulin sensitivity. All tests were performed before surgery and 3 months postoperatively.
Three months after surgery, a significant increase in insulin sensitivity (mean change +/- SEM 34.0 +/- 10.4, P < .0001) was present. The VAT area had significantly decreased (-66.1 +/- 17.8 cm2, P = .002) and was associated with decreases in body mass index, serum glucose concentrations, and high-sensitivity C-reactive protein levels (r = .61 and P = .005, r = .48 and P = .033, and r = .53 and P = .016, respectively). The LV mass decreased significantly (-3.8 +/- 1.7 g/m(2.7), P = .037), and this decrease was associated with a decrease in glucose concentration (r = .46, P = .041). The LV systolic and diastolic contractile function were normal at baseline, and no change occurred after surgery.
The early phase of weight loss after bariatric surgery produces favorable changes in LV geometry, and these are associated with normalization in the glucose metabolism.
Surgery for Obesity and Related Diseases 2(6):592-9. · 3.93 Impact Factor
