Exercise may help attenuate age-related increases in aortic stiffness, but physical activity alone may not be sufficient to improve aortic stiffness in some older adults. Researchers conducted a study to determine the effects of aerobic exercise training with and without caloric restriction on the structure and function of the proximal aorta in older adults with obesity.
A total of 160 men and women who were 65 to 79 years old and had a body mass index of 30 to 45 kg/m2 were randomly assigned to one of three interventions for 20 weeks: aerobic exercise training only; exercise plus moderate caloric restriction; or exercise plus high caloric restriction. The researchers assessed the structure and function of the proximal aorta using cardiovascular magnetic resonance imaging.
Weight loss was greater in both caloric restriction groups than in the exercise-only group. There was a significant treatment effect for descending aorta distensibility. The exercise-plus-moderate-caloric-restriction group had higher postintervention descending aorta distensibility and a decrease in aortic arch pulse wave velocity compared with the exercise-only group. No significant changes in aortic structure and function were seen in the exercise-only and exercise-plus-high-caloric-restriction groups. The researchers found that increases in aortic distensibility were correlated with improvements in body weight and fat distribution, but these associations were no longer significant after adjusting for multiple comparisons.
The findings suggest that exercise without weight loss had little effect on aortic stiffness in obese older adults. The addition of moderate caloric restriction appears to maximize improvements in aortic stiffness, but high caloric restriction may not be necessary or advised.
A limitation of the study was that the researchers used brachial rather than aortic blood pressure to calculate aortic distensibility. In addition, the study lacked a nonexercise control group and the lifestyle intervention was also relatively short, the authors note.