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.
The decline in fat mass and lean mass after weight loss surgery is associated with a decline in left ventricular mass.
Fifteen severely obese women (mean body mass index or BMI: 46.7 ± 1.7 kg/m2) with medically controlled hypertension underwent bariatric surgery. Left ventricular mass and plasma markers of systemic metabolism, together with BMI, waist and hip circumferences, body composition (fat mass and lean mass), and resting energy expenditure (REE) were measured at 0, 3, 9, 12 and 24 months.
Left ventricular mass continued to decline linearly over the entire period of observation, while rates of weight-loss, loss of lean mass, loss of fat mass, and REE all plateaued at 9 months (p<0.001 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 decline of left ventricular mass after weight loss surgery is regulated by neurohumoral factors, and may contribute to improved long-term survival.
Keywords: obesity, weight loss, metabolism, bariatric surgery, left ventricular mass, insulin resistance