Table 2.

The effects of pulmonary rehabilitation on exercise capacity, immunity and blood chemistry in COVID-19 patients during the 6-month convalescence period.

	Control group		PR group		Unadjusted analysisa		Adjusted analysisb
	Baseline	Change	Baseline	Change	Diff. between changes		Diff. between changes
	Mean ± SD	Mean ± SD	Mean ± SD	Mean ± SD	95% CI	p Value	95% CI	p Value
Exercise capacity (N = 98, control 71, PR 27)
6-MWD, m	538 ± 68	60 ± 58	365.8 ± 59.0	254 ± 67	194 (167–221)	<.001	123 (66–181)	<.001
SARS-CoV-2 specific immunoglobulins (N = 77, control 55, PR 22)
IgG, U	13.9 ± 13.5	–5.1 ± 13.4	17.7 ± 14.4	–4.9 ± 15.6	0.3 (–7.4 to 8.0)	.84	–4.0 (–20.7 to 12.7)	.64
IgM, U	1.5 ± 2.5	–0.6 ± 2.6	1.6 ± 1.7	–1.0 ± 1.6	–0.4 (–1.4 to 0.6)	.44	–0.7 (–3.6 to 2.1)	.60
T lymphocytes (N = 38, control 25, PR 13)
CD3+, cells/µL	1161 ± 404	51 ± 271	1045 ± 424	63 ± 231	12 (–160 to 184)	.89	–82 (–462 to 299)	.67
CD4+, cells/µL	550 ± 200	40 ± 137	507 ± 219	45 ± 96	5 (–72 to 82)	.90	37 (–147 to 220)	.69
CD8+, cells/µL	565 ± 250	–4 ± 135	492 ± 262	12 ± 150	17 (–89 to 119)	.74	–107 (–309 to 94)	.29
CD4+/CD8+ ratio	1.1 ± 0.5	0.03 ± 0.2	1.2 ± 0.6	0.09 ± 0.2	0.05 (–0.09 to 0.2)	.46	0.1 (–0.3 to 0.4)	.69
Blood chemistry (N = 98, control 71, PR 27)
WBC, ×109 cells/L	6.5 ± 1.8	–0.5 ± 1.0	6.6 ± 2.1	–0.7 ± 1.2	–0.2 (–0.7 to 0.3)	.43	–1.0 (–2.1 to 0.2)	.10
Lymph., ×109 cells/L	1.8 ± 0.6	0.6 ± 0.6	1.6 ± 0.7	0.6 ± 0.5	0.01 (–0.2 to 0.2)	.98	–0.3 (–0.9 to 0.3)	.34
Neu., ×109 cells/L	4.2 ± 1.5	0.1 ± 1.0	4.4 ± 1.7	–0.1 ± 1.3	–0.3 (–0.9 to 0.3)	.28	–1.0 (–2.2 to 0.3)	.12
Eos., ×109 cells/L	0.13 ± 0.09	–0.01 ± 0.06	0.10 ± 0.09	0.01 ± 0.05	0.01 (–0.02 to 0.03)	.70	0.01 (–0.06 to 0.07)	.94
Haemoglobin, g/L	139.6 ± 14.5	9.5 ± 6.3	129.7 ± 20.7	7.6 ± 6.5	–1.9 (–4.8 to 1.0)	.19	–1.6 (–8.5 to 5.3)	.64
Platelets, ×109/L	225.9 ± 50.0	–28.6 ± 26.7	216.3 ± 93.3	–23.7 ± 26.0	5.0 (–6.9 to 16.9)	.40	17.1 (–11.9 to 46.1)	.24
ALT, U/L	29.3 ± 21.4	1.4 ± 11.7	22.8 ± 13.1	2.3 ± 3.6	0.9 (–2.0 to 3.9)	.58	2.8 (–8.3 to 14.0)	.62
AST, U/L	23.4 ± 9.5	1.3 ± 6.0	21.7 ± 6.0	0.8 ± 2.7	–0.5 (–2.3 to 1.2)	.54	–1.6 (–4.2 to 7.4)	.58
Total bilirubin, μmol/L	9.4 ± 3.9	1.7 ± 3.4	9.8 ± 4.4	1.5 ± 2.6	–0.3 (–1.6 to 1.0)	.67	–0.2 (–3.7 to 3.4)	.93
Total protein, g/L	73.1 ± 3.7	–1.0 ± 3.8	72.8 ± 5.1	–0.3 ± 2.8	0.6 (–0.8 to 2.0)	.36	1.1 (–2.8 to 5.0)	.58
Albumin, g/L	45.0 ± 3.3	0.6 ± 3.2	44.8 ± 3.4	0.5 ± 2.6	–0.1 (–1.3 to 1.2)	.92	1.3 (–2.0 to 4.6)	.45
Globulin, g/L	28.0 ± 4.1	–1.6 ± 3.7	28.0 ± 5.2	–0.9 ± 4.4	0.7 (–1.3 to 2.6)	.47	–0.3 (–4.5 to 4.0)	.90
Albumin/globulin ratio	1.7 ± 0.4	0.1 ± 0.3	1.7 ± 0.4	0.1 ± 0.4	–0.1 (–0.3 to 0.1)	.39	0.1 (–0.3 to 0.5)	.71
BUN, mmol/L	4.5 ± 1.0	0.9 ± 0.8	4.8 ± 1.2	0.9 ± 0.8	0.04 (–0.3 to 0.4)	.80	0.3 (–0.6 to 1.1)	.53
Uric acid, μmol/L	360.9 ± 84.7	12.9 ± 45.9	342.2 ± 95.6	6.2 ± 59.4	–6.7 (–32.3 to 18.9)	.60	–27.6 (–61.1 to 48.5)	.82
Creatinine, μmol/L	67.3 ± 13.2	0.9 ± 10.4	67.3 ± 21.1	0.9 ± 8.4	0.01 (–4.0 to 4.1)	.99	–1.4 (–12.3 to 9.4)	.80

PR: pulmonary rehabilitation; SD: standard deviation; 95% CI: 95% confidence interval; 6-MWD: six-minute walk distance; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; WBC: white blood cells; CD3+: mature human T lymphocytes; CD4+: helper/inducer T lymphocytes; CD8+: suppressor/cytotoxic T lymphocytes; WBC: white blood cell; Lymph.: lymphocytes; Neu.: neutrophils; Eos.: eosinophils; ALT: alanine aminotransferase; AST: aspartate aminotransferase; BUN: blood urea nitrogen.

^a The difference between the changes across groups was assessed by independent t-test and Wilcoxon’s rank sum test for normal and non-normal distribution variables, respectively.

^b The difference between the changes across groups was evaluated by analysis of covariance (ANCOVA) with a covariate of propensity score that adjusted for sex, age, body weight, baseline exercise capacity (6-MWD), physical activity per week during 6-month convalescence period, and COVID-19 classification, comorbidity and the use of antibiotics during hospitalization.