Table 2. The relationship between LL-37, 25(OH)D and exacerbation risk in COPD patients.

Variables	LL-37			25(OH)D
	r	P		r	P
25(OH)D	0.115	0.303		1
Age	0.154	0.162		0.039	0.725
FEV1%pred	0.132	0.247		0.343*	0.002
FEV1/FVC	0.036	0.756		0.317*	0.005
Exacerbations per year	−0.227	0.052		−0.341*	0.003
mMRC score	−0.282	0.096		−0.277	0.112

*, there is correlation between two indexes. 25(OH)D, 25-hydroxy vitamin D; COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in one second; FVC, forced vital capacity; mMRC, Modified British Medical Research Council.