Submitted on October 24, 2007
Accepted on December 21, 2007
The Effects of Caloric Restriction- and Exercise-Induced Weight Loss on Left Ventricular Diastolic Function
Matt M. Riordan1, Edward P Weiss2, Timothy E Meyer2, Ali A Ehsani3, Susan B Racette4, Dennis T Villareal4, Luigi Fontana2, John O Holloszy4, and Sandor J. Kovacs5*
1 Biomedical Engineering, Washington University, St. Louis, Missouri, United States
2 Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States
3 Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States; St. Louis, Missouri, United States
4 St. Louis, Missouri, United States; Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States
5 Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States; Biomedical Engineering, Washington University, St. Louis, Missouri, United States
* To whom correspondence should be addressed. E-mail: sjk{at}wuphys.wustl.edu.
Little is known about the effects of weight loss on diastolic function (DF). Furthermore, it is not known if both caloric restriction (CR)- and exercise (EX)-induced weight loss have salutary effects on DF. Therefore, we assessed the effects of yearlong CR (n=12) and EX (n=13) interventions, which induced ~12% weight loss, on DF in healthy, non-obese (BMI=23.5-29.9 kg/m2) men and women aged 50-60 years. Recordings of Doppler transmitral flow and Doppler tissue imaging were acquired and analyzed by conventional approaches and a validated parameterized diastolic filling (PDF) formalism. Isovolumic relaxation time decreased after weight loss in both groups (p<0.05). Septal E' increased (p<0.01) and E/E' decreased (p<0.05) after weight loss in the CR group. Based on the PDF-derived indices, CR resulted in a decrease in global ventricular stiffness (k) and increases in longitudinal (septal annulus motion) stored elastic strain (xo'), peak force (k'xo'), and peak stored strain energy (1/2k'xo'2). In the exercise group, k was unchanged, although septal xo' and 1/2k'xo'2 increased significantly and k'xo' tended (p=0.13) to increase. We conclude that weight loss, whether induced by caloric restriction or exercise, has salutary effects on DF.
