Serum High-Density Lipoprotein Cholesterol Levels as a Prognostic Indicator in Patients With Idiopathic Pulmonary Arterial Hypertension

Abstract

High-density lipoprotein (HDL) cholesterol levels are a strong, independent inverse predictor of cardiovascular disease. The present study aimed to determine whether serum HDL cholesterol levels correlated with disease severity and clinical outcomes in patients with idiopathic pulmonary arterial hypertension (IPAH). The serum HDL cholesterol levels were measured in 76 Chinese patients with IPAH and 45 healthy controls, together with other clinical variables. Univariate and multivariate Cox proportional hazards analysis was performed to assess the prognostic value of HDL cholesterol and event-free survival. Event-free survival was estimated using the Kaplan-Meier method. Serum HDL cholesterol levels were significantly decreased in patients with IPAH compared with controls (1.0 ± 0.3 vs 1.5 ± 0.3 mmol/L; p <0.001). The serum HDL cholesterol levels decreased in proportion to the severity of World Health Organization functional class. Compared to the high HDL cholesterol group, the low HDL cholesterol group demonstrated a significantly lower 6-minute walking distance, cardiac index, mixed venous saturation, and arterial carbon dioxide pressure but significantly greater pulmonary vascular resistance and serum uric acid levels. The serum HDL cholesterol levels correlated positively with the cardiac index (r = 0.42; p = 0.002) and negatively with the pulmonary vascular resistance (r = -0.25; p = 0.04). Serum HDL cholesterol was independently related to event-free survival on multivariate Cox proportional hazards analysis. Kaplan-Meier survival curves according to the median HDL cholesterol value showed that lower HDL cholesterol levels were associated with lower event-free survival. In conclusion, serum HDL cholesterol levels might serve as an indicator of disease severity and prognosis in patients with IPAH.