Predictors of improvement in endothelial function after exercise training in a diverse sample of postmenopausal women

Abstract

Background: Endothelial dysfunction measured via flow-mediated dilation (FMD) is associated with greater risk of future hypertension and cardiovascular events in postmenopausal women. Aerobic exercise training has been shown to improve endothelial function in Caucasian populations, but has not been evaluated specifically in African Americans. This has clinical importance due to the increased prevalence of cardiovascular disease in African Americans.

Methods: In the present pilot study, 8 African American (age: 55.8±1.7 years, peak oxygen uptake [VO2 peak]: 21.0±3.9 mL/kg/minute, body mass index [BMI]: 30.1± 6.3 kg/m(2)) and 16 Caucasian (age: 57.2±5.9 years, VO2 peak: 21.8±3.7 mL/kg/minute, BMI: 29.3±5.2 kg/m(2)) sedentary postmenopausal women underwent brachial artery FMD measurements before and after 12 weeks of aerobic exercise training. FMD was quantified by comparing B-mode ultrasound images of the brachial artery at rest and following reactive hyperemia after 5 minutes of forearm occlusion. Participants performed aerobic exercise training 4 days per week for 12 weeks.

Results: Despite improvements in fitness in both groups, aerobic exercise training did not significantly improve FMD in African American (5.8% to 5.7%, p=0.950) or Caucasian postmenopausal women (5.7% to 6.6%, p=0.267). In women with the greatest impairment in endothelial function at baseline (FMD<4.5%), a significant improvement in FMD was observed, independent of race, following exercise training (2.2% to 6.2%, p=0.007).

Conclusion: The benefits of aerobic exercise training on endothelial function in postmenopausal women are most pronounced in women with endothelial dysfunction prior to training and do not appear to be affected by race.

Figures

FIG. 1.

Change in flow-mediated dilation (FMD) following aerobic exercise training in (A) African American and Caucassian participants; (B) participants with impaired (<4.5%) and not impaired (>4.5%) FMD at baseline; (C) participants with impaired FMD (lower 50th percentile) and not impaired (upper 50th percentile) based on median split. Changes in FMD are expressed as adjusted least square means±95% confidence intervals. *Significantly greater change in FMD in women who had impaired FMD at baseline compared to those that had normal FMD levels at baseline.