NORTH CAROLINA: According to a new study led by researchers at Wake Forest School of Medicine, small lifestyle changes can make a big difference in improving vascular health in older adults with obesity.
The study was published in the current issue of the American Heart Association's journal Circulation.
Eliminating just 200 calories a day combined with 30 minutes of moderate to vigorous aerobic exercise four days a week was associated with significant improvement in aortic stiffness, a measure of vascular health.
"We were surprised to find that moderate caloric reduction and aerobic activity had a better effect on arteries than exercise with a more restrictive diet," said lead study author Tina E. Brinkley, Ph.D., associate professor of gerontology and geriatric medicine at Wake Forest School of Medicine.
"These relatively small changes should be manageable for people and more sustainable over the long term," added Brinkley.
The randomized controlled trial included 160 sedentary adults, aged 65 to 79 years with obesity defined as a body mass index of 30 to 45 kg/m2. The average age of the participants was 69 years with 74 per cent female and 73 per cent white.
Study participants were randomly assigned to one of three intervention groups for 20 weeks: exercise only, exercise plus moderate calorie restriction or exercise plus more intensive calorie restriction. Everyone in the study received supervised aerobic exercise training four days a week at the Geriatric Research Center at Wake Forest School of Medicine. To determine the participants' vascular health, the structure and function of the aorta were measured and assessed using cardiac MRI.
The aorta, the largest artery in the body, delivers oxygen and vital nutrients from the heart to key organs. As the aorta stiffens in the typical healthy aging process, the heart must work harder to contract and pump blood throughout the body.
Higher body mass index, body weight, total body fat and abdominal fat, as well as a larger waist circumference are all associated with higher aortic stiffness, which is a risk factor for cardiovascular events including heart attack and stroke, and even death, Brinkley said.
The research team found that weight loss of approximately 10 per cent of total body weight or about 20 pounds over the five-month study period was associated with significant improvements in aortic stiffness only in the participants assigned to the exercise plus moderate calorie restriction group. None of the aortic stiffness measures changed significantly in either the exercise-only group or the exercise plus more intensive calorie restriction group.
In addition, changes in body mass index, total fat mass, percent body fat, abdominal fat and waist circumference were greater in both of the calorie-restricted groups compared to the exercise-only group. Weight loss was similar between the calorie-restricted groups despite nearly two times fewer calories in the more intensive group. However, the group with the more restrictive diet did not show any improvements in aortic stiffness even though it had similar decreases in weight and blood pressure as the moderately restrictive group.
"Our findings indicate that these moderate lifestyle changes may help reduce aortic stiffness and improve overall vascular health in older adults," Brinkley said.