Prognostic role of traditional cardiovascular risk factors in patients with idiopathic pulmonary arterial hypertension

INTRODUCTION: Metabolic alterations have been recently associated with onset and progression of idiopathic pulmonary arterial hypertension (IPAH). We aimed to determine the prevalence and prognostic role of cardiovascular risk factors in patients with IPAH. MATERIAL AND METHODS: Between February 2009 and January 2015 we recruited consecutive IPAH patients. Clinical assessment included medical history, fasting glucose, lipid profile, N-terminal pro-brain natriuretic peptide concentration, 6-minute walk test distance, WHO functional class and hemodynamic evaluation. Patients’ risk was estimated based on the Swedish PAH Register grading system. RESULTS: The study group included 61 IPAH patients, and the control group included 2413 Polish residents. When compared to the general population, IPAH patients had lower low-density lipoprotein cholesterol (LDL-C) and a higher triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio. Female patients were characterized by elevated glucose level, higher prevalence of diabetes and lower HDL-C than controls. PAH severity grade correlated positively with age and TG/HDL-C ratio (R = 0.29, p = 0.02) and inversely with LDL-C (R = –0.28, p = 0.03) and HDL-C (R = –0.39, p = 0.02) concentrations. After a follow-up of 48 (23–79) months we recorded 28 deaths in the IPAH group. In the regression analysis lower LDL-C (p = 0.002) and HDL-C (p = 0.0002) levels, and higher TG/HDL-C ratio (p = 0.003) and glucose level (p = 0.003) were associated with all-cause mortality after adjustment for age, sex or PAH severity grade. CONCLUSIONS: Patients with IPAH are characterized by an altered profile of lipid and glucose metabolism. Lowered levels of LDL-C and HDL-C and increased TG/HDL-C ratio correlate with disease severity and together with elevated plasma glucose level predict poor survival in IPAH.