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Exp Physiol. 2021 Jul 26. doi: 10.1113/EP089820. Online ahead of print.
NEW FINDINGS: What is the central question of this study? This study sought to investigate whether central and peripheral hemodynamics during handgrip exercise were different in young adults 3-4 weeks following infection with of SARS-CoV-2 compared with young healthy adults. What is the main finding and its importance? The main findings are that exercising heart rate was higher while brachial artery blood flow and vascular conductance were lower in the SARS-CoV-2 compared with the control group. These findings provide evidence for peripheral impairments to exercise among adults with SARS-CoV-2, which may contribute to exercise limitations.
ABSTRACT: The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can have a profound impact on vascular function. While exercise intolerance may accompany a variety of symptoms associated with SARS-CoV-2 infection, the impact of SARS-CoV-2 on exercising blood flow (BF) remains unclear.
METHODS: Central (photoplethysmography) and peripheral (Doppler ultrasound) hemodynamics were determined at rest and during rhythmic handgrip exercise at 30% and 45% of maximal voluntary contraction (MVC) in young adults with mild symptoms 25 days after testing positive for SARS-CoV-2 (SARS-CoV-2: n = 8M/5F; Age: 21±2yrs; Height: 176±11cm; Mass: 71±11kg) and were cross-sectionally compared with control subjects (Control: n = 8M/5F; Age: 27±6yrs; Height: 178±8cm; Mass: 80±25kg).
RESULTS: Systolic blood pressure, end systolic arterial pressure, and rate pressure product were higher in the SARS-CoV-2 group during exercise at 45%MVC compared with Controls. Brachial artery BF was lower in the SARS-CoV-2 group at both 30%MVC (Control: 384.8±93.3ml·min-1 ; SARS-CoV-2: 307.8±105.0ml·min-1 ; p = 0.041) and 45%MVC (Control: 507.4±109.9ml·min-1 ; SARS-CoV-2: 386.3±132.5ml·min-1 ; p = 0.002). Brachial artery vascular conductance was lower at both 30%MVC (Control: 3.93±1.07ml·min-1 ·mmHg-1 ; SARS-CoV-2: 3.11±0.98ml·min-1 ·mmHg-1 ; p = 0.022) and 45%MVC (Control: 4.74±1.02ml·min-1 ·mmHg-1 ; SARS-CoV-2: 3.46±1.10ml·min-1 ·mmHg-1 ; p<0.001) in the SARS-CoV-2 group compared to Control group. The shear-induced dilation of the brachial artery increased similarly across exercise intensities in the two groups, suggesting the decrease in exercising blood flow may be due to microvascular impairments.
CONCLUSION: Brachial artery BF is attenuated during handgrip exercise in young adults recently diagnosed with mild SARS-CoV-2, which may contribute to diminished exercise capacity among those recovering from SARS-CoV-2 like that seen in severe cases. This article is protected by copyright. All rights reserved.