Progressive regression of left ventricular hypertrophy two years after bariatric surgery

Abstract

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.

Figure 1

Figure 1A: Decline of the BMI over time. The rate of decline of BMI was greatest in the initial 6 months following surgery. Thereafter, the BMI continues to decline at a slower rate. Figure 1B: Comparison of the Body Masses (fat mass and lean mass) after surgery. The decrease in lean mass and fat mass was greatest during the first month after surgery. Lean mass plateaued after 1 month, while fat mass continued to decrease sharply until 6 months and then slowed over the subsequent months.

Figure 2

Figure 2A: Progressive decline in left ventricular mass (LVM): Left ventricular mass declined progressively and normalized by 9 months (normal cut-off for women is 46.7 g/m^2.7). Figure 2B: Correlation of left ventricular mass to lean mass at 9 months. Pearson’s correlation indicated a strong correlation of left ventricular mass and lean mass at 9 months, but not at other time period.

Figure 3

Fractional Change form Baseline of left ventricular mass and Plasma Markers of Obesity after Bariatric Surgery: Left ventricular mass declines linearly over the 24-month time period while plasma markers of obesity decline sharply in the initial 3 months and nadir at 9 months. Thereafter the plasma markers begin to increase towards, but not to, the pre-operative levels.