Correlation of diaphragm thickness with pulmonary function test in Parkinson’s disease

Table 1 Comparison of demographic, clinical, spirometry, and ultrasound findings in early and advanced stage Parkinson’s disease patients

	Early stage (n = 16)	Advanced stage (n = 27)	Total (n = 43)	P value
Age	66.1 ± 8.3	68.3 ± 10.9	67.5 ± 1	0.490
Gender (M/F)	8/8	13/14	21/22	0.907
mMRC	1 (0-4)	2 (0-3)	1 (0-4)	0.012
pSO2	96 (93-99)	96 (57-98)	96 (57-99)	0.487
Disease duration (months)	12 (1-120)	72 (1-300)	48 (1-300)	0.001
Heart rate	79.8 ± 12.6	80 ± 16.4	79.9 ± 15	0.974
FEV1%	81.1 ± 17.2	87.5 ± 12.4	85.1 ± 14.5	0.168
FVC%	83 ± 15.4	85.4 ± 19	84.5 ± 17.6	0.666
FEV1/FVC%	78.8 ± 6.3	81 ± 8.8	80.2 ± 8	0.392
PEF%	56.4 ± 15.8	63.9 ± 17.2	61.1 ± 16.9	0.162
MMEF%	68.6 ± 28.7	83.2 ± 24.1	77.6 ± 26.6	0.084
Diaphragm thickness during inspiration	3.7 ± 1.1	3.5 ± 1	3.6 ± 1	0.619
Diaphragm thickness during expiration	2.7 ± 0.7	2.5 ± 0.8	2.6 ± 0.8	0.482
Diaphragm fractional index	36.4 ± 21.4	40.3 ± 25.7	38.9 ± 24	0.639

M: Male; F: Female; mMRC: Modified medical research council; FEV1: Forced expiratory volume in the first second; FVC: Forced vital capacity; PEF: Peak expiratory flow; MMEF: Maximal-mid expiratory flow; pSO₂: Peripheral oxygen saturation.