Table 2.

Main characteristics of the studies included in the meta-analysis.

Study	Subjects M/Fa	Age (years)b	Type of study	Sample size	Death cases	Length of stay (days)	Main outcomes	Other outcomes
Tuzun et al. (28)	Hospitalized COVID-19 patients All: 77/73 Severe: 25 /22 Non-severe: 52/51	All: 53.17 ± 15.49 Severe: 58.81 ± 14.50 Non-severe: 50.60 ± 15.31	Cross-sectional Study	All: 150 Severe: 47 Non-severe: 103	NR	NR	Lower grip strengths in Female patients with severe infections.	CRP was significantly higher in Lower grip strengths, female patients.
Kara et al. (26)	Hospitalized COVID-19 patients All: 172/140 Mild: 65/50 Moderate: 86/73 Severe: 21/17	All: 46.1 ± 14.8 Mild: 39 (21–74)c Moderate: 46 (20–90)c Severe: 61 (42–90)c	Cross-sectional Study	All: 312 Mild:115 Moderate: 159 Severe: 38	NR	All: 9 (2–30)c Mild: 8 (2–19)c Moderate: 8 (3–21)c Severe: 18 (6–30)c	Length of hospital stay and CRP were higher in the severe group vs. other groups. In addition, mean grip strength values were lower in severe vs. other groups.	BMI was lower in the mild vs. other groups. Age, obesity, CRP level, and low grip strength were found to be independent predictors for severe disease.
Rossi et al. (27)	Severe COVID-19 patients admitted in ICU All: 121/32 Survivors: 100/26 Deaths: 21/6	All: 64.19 ± 9.98 Survivors: 63.32 ± 10.50 Deaths: 68.26 ± 5.55	Cohort Prospective Study	All: 153 Survivors: 126 Deaths: 27	27	NR	Survivors showed lower age, BMI, IMAT area, and CRP than death subjects.	CRP level was significantly higher in subjects in the highest IMAT/muscle tertile than subjects in the lowest tertile.
Viddeleer et al. (20)	Hospitalized COVID-19 patients All: 129/86 Alive: 102/73 Dead: 27/13	All: 61.1 ± 14.3 Alive: 59.8 ± 14.5 Dead: 66.9 ± 12.0	Cohort Prospective	All: 215 Alive: 175 Dead: 40	40	NR	Non-survivors had a larger CSA of IMAT and a more extensive IMAT index compared with survivors.	Patients who died were older and more frequently invasively ventilated.
Gil et al. (18)	Hospitalized COVID-19 patients All: 93/93 Survivors: 86/88 Deaths: NR	All: 59 ± 15 Survivors: NR Deaths: NR	Cohort Prospective Study	All: 186 Survivors: 174 Deaths: 12	12	All: 7 (4–11)d Survivors: 7 (4–11)d Deaths: NR	Muscle strength and mass (vastus lateralis by US) are predictors of LOS in patients with moderate to severe COVID-19.	An association between increased handgrip strength and shorter hospital stay was identified when standardized handgrip strength. The mean LOS was shorter for the most muscular patients vs. others. The mean LOS for the patients with the lowest CSA was longer.
Yi et al. (30)	Hospitalized COVID-19 patients All: 133/101 Severe: 23/8 Non-severe: 110/93	All: 44.5 (2.0–81.0)c Severe: 45.0 (26.0–80.0)c Non-severe:43.0 (2.0–81.0)c	Cohort Retrospective Study	All: 234 Severe: 31 Non-severe: 203	NR	NR	Myosteatosis seems to be associated with a higher risk of transition to severe illness in patients affected by COVID-19 who initially presented mild infection.	Patients with severe illness showed significantly higher SMFI and higher incidence of myosteatosis.
Yang et al. (29)	Hospitalized COVID-19 patients All: 70/73 Critical: 27/18 Non-critical: 43/55	All: 66 (56–73.5)c Critical: 67 (60–75)c Non-critical: 65 (54.3–73)c	Cohort Retrospective Study	All: 143 Critical: 45 Non-critical: 98	Critical: 15 Non-critical: 0	NR	Patients with VA or high IMF deposition were older, and they had significantly higher risks for MV than patients without those features. Furthermore, VA or high IMF deposition were independent risk factors for critical illness.	Patients aged <60 years with visceral adiposity and high IMF deposition had higher risks for critical illness.

^aM/F, male/female.

^bCompleted patients.Values are mean ± SD unless otherwise specified.

^cMedian (min to max).

^dMedian (IQR).

NR, not reported data; CRP, C-reactive protein; BMI, Body mass index; CSA, Cross-sectional area; IMAT, Intermuscular adipose tissue; SMFI, Septocutaneous muscle fat index; MFI, Muscle fat index; VA, visceral Adiposity; IMF, Intramuscular fat; MV, Mechanic ventilation.