Regular Physical Activity Improves Endothelial Function in Patients With Coronary Artery Disease by Increasing Phosphorylation of Endothelial Nitric Oxide Synthase
Why the study?
Does exercise training improve endothelial function in patients with stable CAD?
Population
35 patients with stable coronary artery disease (CAD) undergoing bypass surgery (n=17 training, n=18 control)
Comparison
Exercise training for 4 weeks vs Control group (no exercise training)
Design
Cohort
Follow-up
4 weeks
Authors
Discussion
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Member takes
Implication
Supports endothelial benefits of exercise in stable CAD; hypothesis-generating and requires RCT confirmation before practice change.
Key Points
- To investigate how 4 weeks of exercise training affects endothelial function, eNOS expression, and Akt-dependent eNOS phosphorylation in the left internal mammary artery of patients with stable coronary artery disease.
- Assessed 17 exercise-trained patients and 18 control patients with stable coronary artery disease.
- Invasively measured endothelium-dependent vasodilation and average peak flow velocity (APV) in response to acetylcholine at baseline and at 4 weeks in the left internal mammary artery (LIMA).
- Analyzed eNOS expression and phospho-eNOS-Ser1177, Akt, and phospho-Akt content via Western blot and quantitative RT-PCR in LIMA tissue harvested during bypass surgery.
- Exercise training increased LIMA APV response to acetylcholine by 56±8% (from +48±8% at baseline to +104±11% after 4 weeks, P<0.001).
- Trained patients exhibited 2-fold higher eNOS protein expression (1.0±0.7 vs 0.5±0.3 arbitrary units, P<0.05) and 4-fold higher eNOS Ser1177 phosphorylation (1.2±0.9 vs 0.3±0.2 arbitrary units, P<0.01) in LIMA endothelium compared with controls.
- Akt phosphorylation correlated significantly with phospho-eNOS levels (R=0.80, P<0.05), which in turn correlated with changes in APV (R=0.59, P<0.05).
Structured PICO
Does exercise training improve endothelial function in patients with stable CAD?
P
Population
35 patients with stable coronary artery disease (CAD) undergoing bypass surgery (n=17 training, n=18 control)
I
Intervention
Exercise training for 4 weeks
C
Comparator
Control group (no exercise training)
O
Outcome
Endothelium-dependent vasodilation and average peak flow velocity (APV) in response to acetylcholine in the left internal mammary artery (LIMA)surrogate
Exercise training improves endothelial function in stable CAD patients by increasing Akt-dependent phosphorylation of eNOS.
Cite This Study
Hambrecht et al. (2003) studied this question.