Clinical Research
Obesity and the Heart
Beneficial Cardiovascular Effects of Bariatric Surgical and Dietary Weight Loss in Obesity

https://doi.org/10.1016/j.jacc.2009.02.086Get rights and content
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Objectives

We hypothesized that, in obese persons without comorbidities, cardiovascular responses to excess weight are reversible during weight loss by either bariatric surgery or diet.

Background

Obesity is associated with cardiac hypertrophy, diastolic dysfunction, and increased aortic stiffness, which are independent predictors of cardiovascular risk.

Methods

Thirty-seven obese (body mass index 40 ± 8 kg/m2) and 20 normal-weight subjects (body mass index 21 ± 2 kg/m2) without identifiable cardiac risk factors underwent cardiac magnetic resonance imaging for the assessment of the left and right ventricles and of indexes of aortic function. Thirty of the obese subjects underwent repeat imaging after 1 year of significant weight loss, achieved in 17 subjects by diet and in 13 subjects by bariatric surgery. Seven obese subjects underwent repeat imaging after 1 year of continued obesity.

Results

Left and right ventricular masses were significantly increased, left ventricular diastolic function impaired, and aortic distensibility reduced in the obese. Both diet and bariatric surgery led to comparable, significant decreases in left and right ventricular masses, end-diastolic volume, and diastolic dysfunction, and an increase in aortic distensibility at all levels of the aorta, most pronounced distally (e.g., distal descending aorta 5.1 ± 1.8 mm Hg−1× 10−3before weight loss and 6.8 ± 2.5 mm Hg−1× 10−3after weight loss; p < 0.001). No improvements were observed in continued obesity.

Conclusions

Irrespective of method, 1 year of weight loss leads to partial regression of cardiac hypertrophy and to reversal of both diastolic dysfunction and aortic distensibility impairment. These findings provide a potential mechanism for the reduction in mortality seen with weight loss.

Key Words

obesity
weight loss
hypertrophy
aortic stiffness
diastole

Abbreviations and Acronyms

BMI
body mass index
HOMA-IR
homeostasis model assessment of insulin resistance
LV
left ventricle/ventricular
MR
magnetic resonance
RV
right ventricle/ventricular

Cited by (0)

This work has won the 2008 American Heart Association Nutrition, Physical Activity, and Metabolism Young Investigator Award. The study was supported by a grant from the Wellcome Trust and by the Oxford Partnership Comprehensive Biomedical Research Centre, with funding from the Department of Health's NIHR Biomedical Research Centres funding scheme.