The detailed analysis showed that in both groups, the left ventricle gained an increased capacity to expand to accommodate blood entering during diastole. In the calorie restriction group, the global stiffness of the left ventricle decreased, suggesting that the muscle and connective tissue of the heart more readily sprang back after the contraction phase. This group also experienced a decrease in the internal pressure gradient, indicating that their left ventricles had better suction ability.
The study participants were nonsmokers between ages 50 and 60 and had BMIs between 23.5 and 30, making them high normal to overweight. None of the participants had diabetes, coronary artery disease, stroke, hypertension, cancer or lung disease. Before enrolling in the study, all were relatively sedentary they exercised less than 20 minutes a day or twice a week.
Twelve participants (four men and eight women) were in the calorie restriction group, in which volunteers reduced the amount of calories they ate between 12 percent and 15 percent. Their physical activity did not change. Thirteen participants (six men and seven women) were in the exercise group and increased their exercise to burn the caloric equivalent of the other group's caloric reduction. The exercise group exercised about six days a week for an hour each session walking, running, cycling or doing elliptical training. Their caloric intake did not change.
Kovcs said he feels the study offers encouragement for those who are overweight. "One reason that it's hard to get people to change their behavior and lose weight is that we warn them about conseq
|Contact: Gwen Ericson|
Washington University School of Medicine