Oxygen uptake kinetics and chronotropic responses to exercise are impaired in survivors of severe COVID-19

Author(s)

Longobardi, Igor ; do Prado, Danilo Marcelo Leite ; Goessler, Karla Fabiana ; Meletti, Matheus Molina ; de Oliveira Junior, Gersiel Nascimento ; de Andrade, Danieli Castro Oliveira ; Gualano, Bruno ; Roschel, Hamilton

• Document type: Journal article
• Source: AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY; v. 323, n. 3, p. 8-pg., 2022-09-01.

Abstract

The post-acute phase of coronavirus disease 2019 (COVID-19) is often marked by several persistent symptoms and exertional intolerance, which compromise survivors' exercise capacity. This was a cross-sectional study aiming to investigate the impact of COVID-19 on oxygen uptake (V_O2) kinetics and cardiopulmonary function in survivors of severe COVID-19 about 3-6 mo after in-tensive care unit (ICU) hospitalization. Thirty-five COVID-19 survivors previously admitted to ICU (5 +/- 1 mo after hospital discharge) and 18 controls matched for sex, age, comorbidities, and physical activity level with no prior history of SARS-CoV-2 infection were recruited. Subjects were submitted to a maximum-graded cardiopulmonary exercise test (CPX) with an initial 3-min period of a constant, moderate-intensity walk (i.e., below ventilatory threshold, VT). V_O2 kinetics was remarkably impaired in COVID-19 survivors as evidenced at the on-transient by an 85% (P = 0.008) and 28% (P = 0.001) greater oxygen deficit and mean response time (MRT), respectively. Furthermore, COVID-19 survivors showed an 11% longer (P = 0.046) half-time of recovery of V_O2 (T1/2V_O2) at the off-transient. CPX also revealed cardiopulmonary impairments following COVID-19. Peak oxygen uptake (V_O2peak), percent -predicted V_O2peak, and V_O2 at the ventilatory threshold (V_O2VT) were reduced by 17%, 17%, and 12% in COVID-19 survivors, respec-tively (all P < 0.05). None of the ventilatory parameters differed between groups (all P > 0.05). In addition, COVID-19 survivors also presented with blunted chronotropic responses (i.e., chronotropic index, maximum heart rate, and heart rate recovery; all P < 0.05). These findings suggest that COVID-19 negatively affects central (chronotropic) and peripheral (metabolic) factors that impair the rate at which V_O2 is adjusted to changes in energy demands. (AU)

• FAPESP's process: 20/15678-6 - Effects of a home-based exercise-training program on functional capacity among COVID-19 surviors: a randomized controlled clinical trial
• Grantee: Matheus Molina Meletti
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 19/25032-9 - The role of carnosine on Ca2+ handling, control of oxidative stress and protection against protein glycation: advances and applications of the study life without carnosine
• Grantee: Hamilton Augusto Roschel da Silva
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/07540-4 - Effects of exercise training associated with protein supplementation on bone parameters in older people with sarcopenic obesity under caloric restriction: a randomized controlled clinical trial
• Grantee: Gersiel Nascimento de Oliveira Júnior
• Support Opportunities: Scholarships in Brazil - Doctorate