Aims Although dyslipidemia was an established risk factor for cardiovascular disease, its role in the pathogenesis of pulmonary arterial hypertension (PAH) is still unclear. The aims of the current study were to elucidate the clinical significance of the serum dyslipidemia levels in patients with idiopathic PAH (IPAH).

Methods Serum dyslipidemia levels (total-cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C)) and other clinical datas collected from 90 consecutive adult patients with IPAH from April 2008 to Dec 2009 were retrospectively evaluated in our center. Right heart catheterisation was performed in all patients. Fourty-five age and sex-matched healthy volunteers served as control subjects.

Results The levels of serum TC and HDL-C was significantly decreased in patients with IPAH compared with control subjects (3.77±0.86 vs 4.23±0.73 mmol/l, p<0.05; 1.04±0.31 vs 1.46±0.31 mmol/l, p<0.001 respectively). Serum HDL-C levels decreased in proportion to the severity of WHO function. Compared with the high HDL-C group, the low HDL-C group demonstrated significantly lower in 6 min walk distance (6MWD), cardiac output (CO), mixed venous saturation (SvO₂) and PaCO₂; whereas significantly higher in pulmonary vascular resistance (PVR) and serum uric acid (UA) levels. Serum HDL-C levels positively correlated with 6MWD (r=0.34, p<0.001), CO (r=0.35, p<0.001), SvO₂ (r=0.40, p<0.001) and PaCO₂ (r=0.289, p<0.05); negatively correlated with UA levels (r=−0.43, p<0.001) and PVR (r=−0.30, p<0.05).

Conclusion Serum HDL-C levels correlated with the clinical severity of IPAH and maybe serve as a novel risk factor for the malignant disease.