Associations of Reducing Sedentary Time With Vascular Function and Insulin Sensitivity in Older Sedentary Adults. Am J Hypertens 2016 Jan;29(1):46-53
Date
05/20/2015Pubmed ID
25987647Pubmed Central ID
PMC11025312DOI
10.1093/ajh/hpv063Scopus ID
2-s2.0-84954508774 (requires institutional sign-in at Scopus site) 15 CitationsAbstract
BACKGROUND: We previously reported increased moderate-intensity (3-6 metabolic equivalents (METs)) physical activity (PA) reverses aging-associated vascular endothelial dysfunction, a surrogate marker of cardiovascular risk. Whether reductions in sedentary time alone contribute to this improvement is unknown.
METHODS: Data from 96 adults (aged ≥50 years) enrolled in a randomized control trial evaluating a 12-week intervention to increase PA in sedentary individuals were analyzed. Amount and intensity of activity were measured pre- and post-intervention by step count and accelerometry. Subjects were divided into 3 categories based on change in sedentary activity (<1. 5 METs): (i) ≥5% reduction in sedentary time, (ii) 0-4.99% reduction, and (iii) increase sedentary time. Vascular endothelial function was measured by brachial artery flow-mediated dilation (FMD%) pre- and post-intervention.
RESULTS: Sedentary time decreased overall (P = 0.001), with a 101-minute decrease in category 1 (N = 27, P < 0.001), a 42-minute decrease in category 2 (N = 29, P = 0.003), and a 44-minute increase in category 3 (N = 40, P = 0.02). While FMD% increased in the entire study population (P = 0.008) over 12 weeks, no differences were observed between the categories (P = 0.73). In category 1, FMD% improvement was associated achievement of ≥20 minutes/day of moderate intensity PA in bouts ≥ 10 minutes in length.
CONCLUSIONS: Reductions of up to 100 minutes of sedentary time per day over 12 weeks was not significantly associated with improved vascular endothelial function in older adults. FMD% was significantly higher among those with lower sedentary behavior and concomitant moderate-intensity PA of ≥20 minutes/day in bouts.
Author List
Suboc TB, Knabel D, Strath SJ, Dharmashankar K, Coulliard A, Malik M, Haak K, Widlansky MEAuthor
Michael E. Widlansky MD Associate Director, Professor in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AccelerometryAged
Aged, 80 and over
Aging
Brachial Artery
Cardiovascular Diseases
Endothelium, Vascular
Exercise
Female
Humans
Insulin Resistance
Male
Middle Aged
Motor Activity
Vasodilation
