RESUMO
BACKGROUND/OBJECTIVES: Obesity is independently associated with left ventricular (LV) diastolic dysfunction and altered cardiac morphology. Morbidity and mortality in patients with diastolic dysfunction are similar to values observed in patients with systolic heart failure. We hypothesized that dysfunctional cardiac responses in people with obesity are reversible after weight loss. Thus, we studied the effect of dietary weight reduction on LV diastolic function as well as on cardiac structure using transthoracic echocardiography and tissue Doppler imaging (TDI). SUBJECTS/METHODS: Thirty-two subjects with obesity underwent a 12-week low-calorie fasting phase of a formula diet. Echocardiographic tissue Doppler indices of diastolic function and measurements of cardiac size were obtained prior to and after the fasting phase. RESULTS: A 12-week diet significantly reduced body mass index from 40.3 ± 6.6 kg/m2 to 33.2 ± 6.1 kg/m2 (p < 0.01). Weight loss was associated with a significant reduction in blood pressure and heart rate. Echocardiography revealed diastolic dysfunction in subjects with obesity, which was improved by dieting. After weight loss, trans-mitral Doppler echocardiography showed a significant reduction in A-wave velocity, from 65.8 ± 19.2 cm/s to 57.0 ± 16.8 cm/s, and an increase in E/A ratio from 1.2 ± 0.4 to 1.4 ± 0.5 (p < 0.01). TDI displayed a significantly lower a'-wave velocity (10.3 ± 2.3 cm/s and 8.9 ± 1.7 cm/s; p < 0.01). Left atrial and LV dimensions were normal and remained unchanged after weight loss. CONCLUSION: Obesity is associated with diastolic dysfunction. A 12-week low-calorie diet with successful weight loss can reduce blood pressure and heart rate and partially normalize diastolic dysfunction.
RESUMO
Obesity is associated with an increased risk of heart failure. Little is known about the impact of dietary changes on the cardiac sequelae in obese patients. Twenty-one obese subjects underwent a 12-week low calorie fasting phase of a formula diet. Transthoracic two-dimensional speckle-tracking echocardiography was performed to obtain systolic left ventricular strain before and after weight loss. Body mass index decreased significantly from 38.6 ± 6.2 to 31.5 ± 5.3 kg/m(2), and the total percentage fat loss was 19%. Weight reduction was associated with a reduction in blood pressure and heart rate. Left ventricular longitudinal global peak systolic strain was in the lower normal range (-18.7 ± 3.2%) before weight loss and was unchanged (-18.8 ± 2.4%) after 12 weeks on diet with substantial weight loss. Also, no significant change in global radial strain after weight loss was noted (41.1 ± 22.0 versus 43.9 ± 23.3, p = 0.09). Left atrial and ventricular dimensions were in normal range before fasting and remained unchanged after weight loss. In our study obesity was associated with normal systolic left ventricular function. A 12-week low calorie diet with successful weight loss can reduce blood pressure and heart rate. Systolic left ventricular function and morphology were not affected by rapid weight reduction.