The Effect Of Weight Loss Combined With Aerobic Exercise Training On Arterial Stiffness: Results From The Prevail Pilot Study

Objective: The OPTIFAST diet has known effects for weight loss, but little data exists on the effects of the diet on arterial stiffness. Methods: Overweight and obese (BMI: 34.5 + 4.0) adults (N=17) participated in a 10-week OPTIFAST™ weight loss program and supervised aerobic exercise training (50%-75% VO 2 max). The diet consisted of OPTIFAST meal replacement products with a goal of reducing total caloric intake to 800 kcals/day and attending a weekly weight management class. Aerobic exercise was performed 3 times per week and the exercise volume was progressed from 300 to 700 MET mins. per week at an intensity of 50%-75% VO2 max. The goal of study participants was to achieve a 7% weight loss. Carotid-to-femoral pulse wave velocity, blood pressure (aortic and brachial), vascular age, augmentation index and blood samples were measured in the morning after an overnight fast at baseline and follow-up. A paired t-test was performed to evaluate the change in outcomes variables. Results: The mean percent weight loss in the sample was 9.0% (-8.5 kg), with 83.3% of participants achieving 7% weight loss (94.1% achieving ≥5%). The adherence to the exercise program was 94.9% and attendance in the weight loss classes was 81.8%. There was a reduction in pulse wave velocity (-0.44 m/s, p=0.030), aortic systolic blood pressure (-10.5 mmHg, p<0.001), aortic diastolic blood pressure (-7.8 mmHg, p<0.001), brachial systolic blood pressure (-11.2 mmHg , p<0.001), brachial diastolic blood pressure (-7.7 mmHg, p<0.001), vascular age (-13.4 yrs., p=0.008), resting heart rate (-4.7 bpm, p=0.005), and augmentation index (-7.5%, p=0.008) after the intervention. Change in resting heart rate from the intervention was associated with improvements in augmentation index (r=0.60, p=0.010) and approached significance for pulse wave velocity (r=0.45, p=0.07). Weight loss was associated with reduction in augmentation index (r= 0.56, p=0.02), but not change in PWV (r=-0.07, p=0.78). Changes in other cardiometabolic risk factors (e.g. glucose, insulin, lipids, and body fat) were not associated with improvements in arterial stiffness or blood pressure measures (all ps>0.05). Discussion: A hypo-caloric dietary program in combination with aerobic exercise training improves arterial stiffness, aortic blood pressure, and brachial blood pressure in overweight and obese adults An important limitation of the present study is that we cannot separate the health benefits of the diet from the exercise.