Table 4. Correlation of lung function and respiratory muscle strength parameters with cardinal signs and Unified Parkinson’s Disease Rating Scale subscale III (motor examination) scores in patients with Parkinson’s disease.

Variable	Cardinal signs, r (r2, %)			Motor function, r (r2, %)
	Tremor at rest	Rigidity	Bradykinesia	UPDRS III
FVC	0.05 (0.25)	−0.29 (8.4)*	−0.35 (12.2)*	−0.23 (5.2)
FEV1	0.12 (1.4)	−0.27 (7.2)	−0.41 (16.8)*	−0.25 (6.2)
FEV1/FVC	0.17 (2.8)	0.13 (1.6)	−0.10 (1.0)	-0.002 (0.0004)
PEF	−0.03 (0.09)	−0.35 (12.2)*	−0.37 (13.6)*	−0.31 (9.6)*
FEF25-75%	0.08 (0.64)	−0.25 (6.2)	−0.39 (15.2)*	−0.32 (10.2)*
MIP	−0.04 (0.14)	0.07 (0.4)	0.15 (2.25)	0.15 (2.2)
MEP	−0.03 (0.09)	−0.18 (3.2)	−0.25 (6.2)	−0.32 (10.2)*

UPDRS-III: subscale III of the Unified Parkinson’s Disease Rating Scale. *Pearson’s correlation; p < 0.05.