Table 2.

Results of the univariate analyses of different parameters in patients with IPAH by Cox regression.

Characteristic	Risk ratio	95% CI	P
Age, years	1.009	0.996–1.022	0.180
Sex	0.346	0.078–1.526	0.161
Body mass index	1.113	0.942–1.315	0.207
NT-proBNP	1.000	1.000–1.001	<0.001*
HCY	1.004	1.002–1.006	<0.001*
H2S	1.013	1.007–1.019	<0.001*
Circ_0068481	2.581	1.892–3.514	<0.001*
6MWD	0.993	0.986–0.999	0.030*

Note: *P < 0.05.

IPAH: idiopathic pulmonary arterial hypertension; NT-proBNP: N-terminal pro-B-type natriuretic peptide; HCY: homocysteine; 6MWD: six-minute walking distance.