Table 5. Comparison of the plasma BNP, Fbg, and Apelin content in the three groups ($\overline{\text{x}}$ ± s).

Plasma parameters	Control group (n=125)	COPD/PH− group (n=205)	COPD/PH+ group (n=134)	P-value
BNP (ng/l)	28.1 ± 9.8	158.6 ± 23.0	220.2 ± 18.9	<0.001
Fbg (g/l)	2.5 ± 0.5	4.2 ± 0.5	5.4 ± 0.8	<0.001
Apelin (ng/l)	90.5 ± 8.4	43.9 ± 4.6	29.4 ± 6.2	<0.001