Table 1.
Differences based on VO2 Maximum Exercise Capacity Criterion.
| Total Sample | VO2 peak > 84% pred | VO2 peak ≤ 84% pred | p-value | |
|---|---|---|---|---|
| n (%) | 59 | 35 (59) | 24 (41) | |
| Age, years | 53.9 (15) | 54.7 (15.8) | 52.7 (14) | 0.61 |
| Sex (%) | 0.371 | |||
| Male | 34 (57.6) | 18 (51.4) | 16 (66.7) | |
| Female | 25 (42.4) | 17 (48.6) | 8 (33.3) | |
| Race (%) | 0.183 | |||
| White | 29 (50.0) | 21 (61.8) | 8 (33.3) | |
| African American | 10 (17.2) | 5 (14.7) | 5 (20.8) | |
| Asian | 5 (8.6) | 1 (2.9) | 4 (16.7) | |
| Chinese | 2 (3.4) | 2 (5.9) | 0 (0.0) | |
| Filipino | 4 (6.9) | 2 (5.9) | 2 (8.3) | |
| Latino | 6 (10.3) | 2 (5.9) | 4 (16.7) | |
| Other | 2 (3.4) | 1 (2.9) | 1 (4.2) | |
| Weight loss post-COVID-19 (lbs.) | 14.4 (14.3) | 17.4 (14.4) | 15 (14.5) | 0.457 |
| Hospitalized (%) | 32 (56.1) | 18 (52.9) | 14 (60.9) | 0.749 |
| Inpatient rehabilitation (%) | 21 (36.8) | 12 (35.3) | 9 (39.1) | 0.988 |
| ICU (%) | 23 (41.8) | 12 (37.5) | 11 (47.8) | 0.625 |
| Mechanical ventilation (%) | 20 (36.4) | 11 (34.4) | 9 (39.1) | 0.938 |
| Days from hospital discharge | 69 (57–143) | 64 (55.2–98) | 125 (69–146) | 0.211 |
| Days from positive COVID-19 test diagnosis | 167 (68.8) | 159.3 (68.1) | 177.8 (70) | 0.332 |
| Length of stay, days | 38.1 (26.9) | 32.8 (23.2) | 44.9 (30.7) | 0.249 |
| Days in ICU | 13.5 (10.3) | 12.9 (11.4) | 16 (5.7) | 0.614 |
| FVC % pred | 74 (64–90) | 80 (69–94) | 63.5 (54.2–81.5) | 0.003 |
| FEV1% pred | 82.2 (18.5) | 88.1 (15.9) | 73.6 (18.8) | 0.004 |
| FEV1/FVC | 85.2 (8) | 84.5 (7.7) | 86.3 (8.4) | 0.407 |
| PEF % pred | 95 (83.5–106.5) | 102 (91–110) | 85 (77–95) | 0.001 |
| FEF 25–75% | 100 (82.5–118.5) | 102 (85.5–118.5) | 96.5 (80.2–117) | 0.436 |
| Performance | ||||
| VO2peak (ml/kg/min) | 21.8 (6.1) | 24.3 (5.2) | 18.2 (5.6) | < 0.001 |
| VO2peak (ml/kg/min) % pred | 89.2 (22.2) | 104.2 (12.5) | 67.4 (13.1) | < 0.001 |
| VO2 AT (ml/kg/min) | 12.2 (3) | 13.3 (2.7) | 10.6 (2.7) | < 0.001 |
| Anaerobic threshold (AT/predicted VO2 max x 100) | 57.4 (8.8) | 55.7 (8.1) | 50.0 (9.2) | 0.069 |
| Actual MET | 6.2 (1.7) | 7 (1.5) | 5.2 (1.6) | < 0.001 |
| MET pred | 7.7 (2.8) | 8.6 (2.4) | 6.5 (2.8) | 0.004 |
| Test Duration (n = 38) | 7.44 (1.92) | 7.88 (1.84) | 6.41 (1.76) | 0.031 |
| Test Duration % pred (n = 38) | 79.60 (22.26) | 87.85 (20.55) | 60.10 (11.55) | < 0.001 |
| Circulation | ||||
| Peak systolic | 162.4 (24.2) | 168.7 (23.4) | 153.2 (22.7) | 0.017 |
| Peak diastolic | 80 (70–80) | 80 (70–80) | 70 (66–80) | 0.242 |
| HR reserve (beats/min) | 16 (3.5–27.5) | 6 (0–17.5) | 27 (17–44.5) | < 0.001 |
| HR peak | 149.2 (23.1) | 156.7 (19) | 138.3 (24.5) | 0.004 |
| HR % pred | 89.8 (11.4) | 94.9 (9.2) | 82.3 (10.4) | < 0.001 |
| HR AT | 105.9 (14.9) | 107.8 (13.4) | 103.2 (16.7) | 0.267 |
| HR peak % pred | 71.5 (8.3) | 69.1 (7.5) | 75 (8.2) | 0.007 |
| Cardiovascular Function | ||||
| Peak VO2/HR | 11.6 (9.9–13.7) | 12.4 (10.9–14.4) | 10.7 (9.1–11.9) | 0.002 |
| O2 pulse peak % pred | 79 (12.9) | 78.6 (13.7) | 79.5 (11.7) | 0.772 |
| VO2/HR AT | 9.4 (2.7) | 10.3 (2.7) | 8.2 (2.2) | 0.002 |
| VO2/HR % pred | 99.3 (21) | 110.6 (13.5) | 82.8 (19) | < 0.001 |
| Rate-pressure product (RPP) | 22,700 (18,186–26767.5) | 23,940 (22,176–28730) | 18,144 (15,865–23430) | < 0.001 |
| Ventilation | ||||
| Peak VE (L/min) | 71.5 (24.4) | 80.2 (22) | 58.8 (22.4) | < 0.001 |
| VE % pred (SD) | 81 (21.3) | 87.1 (18.6) | 72 (22.3) | 0.009 |
| VE reserve (range) | 18 (4–29.5) | 17 (0–24.5) | 23 (5.8–37.2) | 0.107 |
| Gas exchange | ||||
| VE/VCo2 AT | 31.8 (29.1–35.6) | 31.6 (28.6–34.6) | 32.5 (29.9–38.7) | 0.208 |
| RER peak | 1.11 (0.12) | 1.13 (0.10) | 1.08 (0.13) | 0.099 |
| SpO2 minimum | 95 (94–97) | 95 (94–97) | 95 (92.8–98) | 0.938 |
Note. AT: at threshold. HR: heart rate. Lbs: pounds. FVC: forced vital capacity. Min: minutes. O2: oxygen; PEF: peak expiratory flow. pred: predicted. RER: respiratory exchange ratio at end of test. RPP: rate-pressure product. VE: minute ventilation. VE/VCo2 AT: ventilatory equivalent for carbon dioxide. VO2: oxygen uptake; VO2/HR: oxygen pulse. VE/VCO2 ratio: ventilatory equivalent for carbon dioxide.