Effect of weight loss on subclinical myocardial injury: A clinical trial comparing gastric bypass surgery and intensive lifestyle intervention

Abstract

Aims: To investigate the effect of weight loss induced by bariatric surgery and intensive lifestyle intervention on levels of circulating high-sensitivity cardiac troponin I.

Methods and results: We measured high-sensitivity cardiac troponin I concentrations pre- and 12 months post-intervention in 136 subjects with morbid obesity participating in a controlled clinical trial comparing the effect of intensive lifestyle intervention vs. Roux-en-Y gastric bypass. At baseline median (interquartile range) high-sensitivity cardiac troponin I levels were 2.40 (1.28-3.95) ng/L in the bariatric surgery group and 2.35 (1.38-4.40) ng/L in the intensive lifestyle intervention group (p = 0.736). The high-sensitivity cardiac troponin I concentration in a normal-weight control group was 0.90 (0.60-2.13) ng/L. During 12 months of follow-up, high-sensitivity cardiac troponin I decreased significantly more in the bariatric surgery group than in the intensive lifestyle intervention group (0.80 (0-1.80) vs. 0.15 (-0.50 to 1.00) ng/L; p = 0.002). In a multivariate logistic regression model, surgery emerged as a predictor of reduction in high-sensitivity cardiac troponin I levels (odds ratio 2.32; 95% confidence intervals 1.03-5.22; p = 0.041) independent of age, gender and other possible confounding baseline variables. In subsequent multivariate analyses, reductions in body weight and triglycerides emerged as possible mediators of reduction in circulating levels of high-sensitivity cardiac troponin I.

Conclusion: In patients with morbid obesity, bariatric surgery was associated with a significantly greater reduction in high-sensitivity cardiac troponin I, an index of subclinical myocardial injury, than intensive lifestyle intervention. The reduction appeared to be mediated by reductions in body weight and serum triglycerides. This suggests that weight loss following bariatric surgery may reduce cardiometabolic stress and subsequent risk of heart failure.

Keywords: Obesity; bariatric surgery; lifestyle intervention; troponin; weight loss.