Faculty Collaboration Database

Relative importance of step count, intensity, and duration on physical activity's impact on vascular structure and function in previously sedentary older adults. J Am Heart Assoc 2014 Feb 26;3(1):e000702

Date

02/28/2014

Pubmed ID

24572255

Pubmed Central ID

PMC3959701

DOI

10.1161/JAHA.113.000702

Scopus ID

2-s2.0-84898609025 (requires institutional sign-in at Scopus site)   60 Citations

Abstract

BACKGROUND: Age-related endothelial dysfunction and vascular stiffening are associated with increased cardiovascular (CV) risk. Many groups have encouraged goals of ≥10 000 steps/day or ≥30 min/day of moderate intensity physical activity (MPA) to reduce age-related CV risk. The impact of MPA on the vasculature of older adults remains unclear.

METHODS AND RESULTS: We randomized 114 sedentary older adults ages ≥50 to 12 weeks of either no intervention (group 1), a pedometer-only intervention (group 2), or a pedometer with an interactive website employing strategies to increase the adoption of habitual physical activity (PA, group 3). Endothelial function by brachial flow-mediated dilation (FMD%), vascular stiffness by tonometry, step-count by pedometer, and PA intensity/distribution by accelerometer were measured. Step-count increased in groups 2 (5136±1554 to 9596±3907, P<0.001) and 3 (5474±1512 to 8167±3111, P<0.001) but not in group 1 (4931±1667 to 5410±2410). Both groups 2 and 3 increased MPA ≥30 min/day. Only group 3 increased MPA in continuous bouts of ≥10 minutes (P<0.001) and improved FMD% (P=0.001). Neither achievement of ≥10 000 steps/day nor ≥30 min/day of MPA resulted in improved FMD%. However, achieving ≥20 min/day in MPA bouts resulted in improved FMD%. No changes in vascular stiffness were observed.

CONCLUSIONS: MPA reverses age-related endothelial dysfunction, but may require MPA to be performed in bouts of ≥10 minutes duration for ≥20 min/day to be effective. Commonly encouraged PA goals do not guarantee improved endothelial function and may not be as effective in reducing CV risk.

CLINICAL TRIAL REGISTRATION URL: Clinicaltrials.gov. UNIQUE IDENTIFIER: NCT-01212978.

Author List

Suboc TB, Strath SJ, Dharmashankar K, Coulliard A, Miller N, Wang J, Tanner MJ, Widlansky ME

Author

Michael E. Widlansky MD Associate Director, Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Actigraphy
Age Factors
Aged
Aging
Brachial Artery
Endothelium, Vascular
Female
Health Behavior
Health Knowledge, Attitudes, Practice
Humans
Male
Manometry
Middle Aged
Motor Activity
Recovery of Function
Risk Factors
Risk Reduction Behavior
Time Factors
Vascular Diseases
Vascular Stiffness
Vasodilation
Wisconsin