Microvascular function is reduced with age, disease, and inactivity. Exercise is well known to improve vascular health and has the potential to improve microvascular function in aging and disease.
The study aimed to assess changes in peripheral microvascular function in sedentary older adults after aerobic exercise training.
Twenty-three sedentary older adults (67 ± 5 yr, body mass index = 29 ± 5, mean ± SD) successfully completed a randomized 12-wk graded treadmill walking intervention. The exercise group (EX) performed 40 min of uphill walking 4 d·wk−1 at 70% heart rate reserve. The control group (CON) maintained a sedentary lifestyle for 12 wk. Blood oxygen level–dependent (BOLD) responses of the soleus measured by magnetic resonance imaging were used to evaluate microvascular function; brief (1 s) maximal plantarflexion contractions were performed. Separately, blood flow in the popliteal artery was measured by ultrasound after brief contraction. Phosphorus magnetic resonance spectroscopy of the calf was used to examine muscle oxidative capacity, and whole-body peak oxygen consumption (V˙O2peak) was used to confirm training-induced cardiorespiratory adaptations.
Peak postcontraction BOLD response increased by 33% in EX (PRE, 3.3% ± 1.0%; POST, 4.4% ± 1.4%) compared with CON (PRE, 3.0% ± 1.3%; POST, 3.2% ± 1.5%), P < 0.05. EX with hypertension tended to show a blunted peak BOLD increase (n = 6, 15%) compared with EX normotensive (n = 7, 50%), P = 0.056. Peak postcontraction blood flow increased by 39% in EX (PRE, 217 ± 88 mL·min−1; POST, 302 ± 167 mL·min−1) compared with CON (PRE, 188 ± 54 mL·min−1; POST, 184 ± 44 mL·min−1), P < 0.05. EX muscle oxidative capacity (kPCr) improved by 40% (PRE, 1.60 ± 0.57 min−1; POST, 2.25 ± 0.80 min−1) compared with CON (PRE, 1.69 ± 0.28 min−1; POST, 1.76 ± 0.52 min−1), P < 0.05. V˙O2peak increased by 9% for EX (PRE, 19.0 ± 3.1 mL·kg−1·min−1; POST, 20.8 ± 2.9 mL·kg−1·min−1) compared with a 7% loss in CON (PRE, 21.9 ± 3.6 mL·kg−1·min−1; POST, 20.4 ± 3.5 mL·kg−1·min−1), P < 0.05.
Moderate aerobic exercise significantly improved microvascular function of the leg in older adults.
1Department of Radiology, Michigan State University, East Lansing, MI;
2Sport and Health Sciences, University of Exeter, Exeter, UNITED KINGDOM;
3Department of Physiology, Michigan State University, East Lansing, MI; and
4Department of Medicine, Michigan State University, East Lansing, MI
Address for correspondence: Jill M. Slade, Ph.D., Radiology Building, Michigan State University, 846 Service Rd, Rm 184, East Lansing, MI 48824; E-mail: email@example.com.
Submitted for publication August 2018.
Accepted for publication November 2018.