title: Aerobic exercise acutely prevents the endothelial dysfunction induced by mental stress among subjects with metabolic syndrome: the role of shear rate.
abstract: Mental stress induces transient endothelial dysfunction, which is an important finding for subjects at cardiometabolic risk. Thus, we tested whether aerobic exercise prevents this dysfunction among subjects with metabolic syndrome (MetS) and whether an increase in shear rate during exercise plays a role in this phenomenon. Subjects with MetS participated in two protocols. In protocol 1 (n = 16), endothelial function was assessed using brachial artery flow-mediated dilation (FMD). Subjects then underwent a mental stress test followed by either 40 min of leg cycling or rest across two randomized sessions. FMD was assessed again at 30 and 60 min after exercise or rest, with a second mental stress test in between. Mental stress reduced FMD at 30 and 60 min after the rest session (baseline: 7.7 ± 0.4%, 30 min: 5.4 ± 0.5%, and 60 min: 3.9 ± 0.5%, P < 0.05 vs. baseline), whereas exercise prevented this reduction (baseline: 7.5 ± 0.4%, 30 min: 7.2 ± 0.7%, and 60 min: 8.7 ± 0.8%, P > 0.05 vs. baseline). Protocol 2 (n = 5) was similar to protocol 1 except that the first period of mental stress was followed by either exercise in which the brachial artery shear rate was attenuated via forearm cuff inflation or exercise without a cuff. Noncuffed exercise prevented the reduction in FMD (baseline: 7.5 ± 0.7%, 30 min: 7.0 ± 0.7%, and 60 min: 8.7 ± 0.8%, P > 0.05 vs. baseline), whereas cuffed exercise failed to prevent this reduction (baseline: 7.5 ± 0.6%, 30 min: 5.4 ± 0.8%, and 60 min: 4.1 ± 0.9%, P < 0.05 vs. baseline). In conclusion, exercise prevented mental stress-induced endothelial dysfunction among subjects with MetS, and an increase in shear rate during exercise mediated this effect.
authors: Laboratory of Exercise Sciences, Department of Physiology and Pharmacology, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil; and.
authors: Allan R K
authors: AR
authors: Sales
authors: Igor A
authors: IA
authors: Fernandes
authors: Natália G
authors: NG
authors: Rocha
authors: Lucas S
authors: LS
authors: Costa
authors: Helena N M
authors: HN
authors: Rocha
authors: João D M
authors: JD
authors: Mattos
authors: Lauro C
authors: LC
authors: Vianna
authors: Bruno M
authors: BM
authors: Silva
authors: Antonio C L
authors: AC
authors: Nóbrega
mesh_terms: D000328:Adult; D001642:Bicycling; D001794:Blood Pressure; D001916:Brachial Artery / Q000503:physiopathology*; D001938:Brazil; D004730:Endothelium, Vascular / Q000503:physiopathology*; D015444:Exercise; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D013314:Stress, Mechanical; D013315:Stress, Psychological / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D013997:Time Factors; D014664:Vasodilation
keywords: aerobic exercise; flow-mediated dilation; mental stress test; shear rate