Hyperaemia during dynamic handgrip exercise is preserved in healthy young subjects after recovery from COVID-19.

ABSTRACT

We sought to investigate possible impaired hyperaemia during dynamic handgrip exercise (HGE) in young healthy individuals who had recovered from COVID-19. We tested the vascular function in individuals recovered from COVID-19 using a nitric oxide donor (i.e., sodium nitroprusside; SNP), which could revert a possible impaired endothelial function during HGE. Further, we tested whether individuals who recovered from COVID-19 would present exaggerated brachial vascular resistance under an adrenergic agonist (i.e., phenylephrine; PHE) stimuli during HGE. Participants were distributed into two groups healthy controls (Control; men n = 6, 30 ± 3 years, 26 ± 1 kg/m2; and women n = 5, 25 ± 1 years, 25 ± 1 kg/m2) and subjects recovered from COVID-19 (post-COVID; men n = 6, 29 ± 3 years, 25 ± 1 kg/m2; and women n = 10, 32 ± 4 years, 22 ± 1 kg/m2). Participants in the post-COVID group tested positive (RT-PCR) 12-14 weeks before the protocol. Heart rate (HR), brachial blood pressure (BP), brachial blood flow (BBF) and vascular conductance (BVC) at rest were not different between groups. The HGE increased HR (Control Δ9 ± 0.4 bpm; and post-COVID Δ11 ± 0.4 bpm) and BP (Control Δ6 ± 1 mmHg; and post-COVID Δ12 ± 0.6 mmHg) in both groups. Likewise, BBF (Control Δ632 ± 38 ml/min; and post-COVID Δ620 ± 27 ml/min) and BVC (Control Δ6.6 ± 0.4 ml/min/mmHg; and post-COVID Δ6.1 ± 0.3 ml/min/mmHg) increased during HGE. SNP did not change HGE-induced hyperaemia but did decrease BP, which induced a reflex-related increase in HR. PHE infusion also did not change the HGE-induced hyperaemia but raised BP and reduced HR. In conclusion, exercise-induced hyperaemia is preserved in healthy young subjects 12-14 weeks after recovery from COVID-19 infection.