Fatigue and perceived fatigability, not objective fatigability, are prevalent in people with post-COVID-19

Abstract

Persistent symptoms after acute COVID-19 infection, termed post-COVID-19 fatigue, occur in 44–70% of patients. Characterizing fatigue in this population is vital to determine the etiology of post-COVID-19 fatigue symptoms and to assess the effectiveness of potential interventions. The purpose of this study was to assess differences in perceived and objective fatigability between people with post-COVID-19 symptoms ( N = 29, 20 females) and people who had COVID-19 but are not experiencing persistent symptoms ( N = 20, 12 females). Perceived fatigability, fatigue, pain, and quality of life were assessed with the Fatigue Severity Scale (FSS), Fatigue Assessment Scale (FAS), Visual Analog Scale for Pain (VAS), and the EQ-5D-5L, respectively. Objective fatigability was evaluated with torque and work fatigue indices (FI-T and FI-W), calculated via an isokinetic fatigue task. The results revealed that, the subjects with post-COVID-19 symptoms had significantly higher FAS ( p < 0.01), FSS ( p < 0.01), VAS ( p < 0.01), and EQ-5D-5L VAS ( p < 0.01) scores compared to subjects without post-COVID-19 symptoms, indicating greater fatigue and perceived fatigability, increased pain, and worse quality of life. However, there were no differences between the two groups for the FI-Ts (all p ≥ 0.07) or FI-W (all p ≥ 0.08), indicating no differences in objective fatigability. This study found that people with post-COVID-19 symptoms have increased fatigue and perceived fatigability, but not objective fatigability, compared to subjects without post-COVID-19 symptoms.

Effect of Post-COVID-19 on Brain Volume and Glucose Metabolism: Influence of Time Since Infection and Fatigue Status

“…190 potential subjects were identified, and thirty-three subjects (17 female) who were previously diagnosed with COVID-19 were eventually enrolled between January 2021 and June 2022. Inclusion criteria were: (1) being between the ages of 18–80, (2) meeting CDC guidelines for discontinuation of home isolation and being at least 6 weeks post-quarantine; (3) having the ability to read, write, speak, and understand English, as well as comprehension of the protocol; (4) confirming the COVID-19 diagnosis via medical record; and (5) experiencing or not experiencing PCS symptoms (depending on group assignment), according to the Chalder Fatigue Scale CFQ-11 (PCS fatigue ≥5 [ 6 , 22 ]; completed via email or phone). Exclusion criteria were: (1) history of traumatic brain injury or hydrocephalus; (2) pregnancy; (3) the presence of any medical condition that may exacerbate any post-COVID-19 symptoms (e.g., major depressive disorder, anxiety disorder); and (4) hospitalization due to COVID-19 infection.…”

“…The Fatigue Severity Scale (FSS) consists of nine statements to evaluate perceived fatigue [ 6 ], each rated on a 7-point scale with higher numbers representing higher agreement with the statement. The scores of each question are averaged to give an overall score between 1 and 7, with a score ≥4 indicating a clinically significant level of fatigue [ 24 ].…”

“…On the contrary, fatigability is a measure of physical or cognitive work capacity. Particularly, perceived fatigue (i.e., feelings of tiredness and lack of energy) and fatigability (i.e., a subjective estimate of future work capacity) have been shown to be more prevalent than objective fatigue (i.e., an objectively measured decrease in performance on a specific task) in people with PCS [ 6 ]. These symptoms have been reported to last over 6 months in some patients [ 7 ], with 20% of subjects reporting fatigue even 1-year post-infection [ 8 ].…”

Measuring objective fatigability and autonomic dysfunction in clinical populations: How and why?

“…Although many exercise protocols have been used in the literature, for instance using maximal incremental test [e.g., ( 22 )], the “classic” fatiguing protocols involve repetitions of sustained MVC [e.g., ( 23 )] or repetitions of MVCs either in isometric [e.g., ( 24 )] or isokinetic mode [e.g., ( 25 )]. Then a fatigue index that consists in normalizing the last contractions to the initial ones is calculated.…”

The challenges of post-COVID-19 fatigue research

“…In this line, Matta et al (2022) suggested that physical symptoms continuing 10-12 months after the first wave of the COVID-19 pandemic may be related more with the idea in having experienced COVID-19 rather than with an actual positive test. Importantly, previous work showed that perceived fatigability and fatigue are more prevalent than objective fatigability in post COVID-19 patients (Fietsam et al, 2022). They compared fatigue, perceived fatigue, and objective fatigability in these patients both with and without reported persistent fatigue symptoms.…”