Table 3. Linear regression analysis between FEV1 and some demographic and biochemical variables in controls and COPD patients.

	Controls (n = 43)		COPD (n = 43)
	r or rho	p-value	r or rho	p-value
Age	-0.34	0.036	-0.31	0.043
Sex	-0.55	<0.0001	--	--
PSH	--	--	0.36	0.016
ADMA/Arginine	--	--	-0.43	<0.0001