[Relationship between serum uric acid levels and patient conditions and prognosis in idiopathic pulmonary arterial hypertension]

Abstract

Objective: To explore the relationship between serum uric acid levels and patient conditions and prognosis in idiopathic pulmonary arterial hypertension (IPAH).

Methods: A total of 76 IPAH patients confirmed by right heart catheterization were enrolled consecutively and followed up until the endpoint of all-cause death. Their baseline data were recorded and analyzed by Spearman's rank test and independent t-test. And the follow-up outcomes were analyzed with Kaplan-Meier plots.

Results: There were 27 males and 49 females with a mean age of 29.7 ± 9.7 years. They were classified into World Health Organization functional class (WHO-FC)II (n = 28), class III (n = 45) and class IV (n = 3). Their baseline mean pulmonary artery pressure was (65 ± 16) mm Hg, pulmonary vascular resistance (1677 ± 669) dyn×s(-1)×cm(-5), pulmonary capillary wedge pressure (9.6 ± 5.0) mm Hg, mean right atrial pressure (9.8 ± 6.1) mm Hg, cardiac index (2.07 ± 0.57) L ×min(-1)× m(-2) and serum uric acid (391 ± 103) µmol/L. The correlation analysis indicated that the serum level of uric acid correlated positively with right ventricular diameter (r = 0.28, P = 0.018) and negatively with CI (r = -0.34, P = 0.003). Independent t-test results indicated that the patients with a higher level of uric acid were apt to have a worse WHO-FC, and the higher level uric acid group (serum uric acid > 416.5 µmol/L) had a relative higher level of WHO-FC, NT-proBNP and endothelin-1. A lower level of CI denoted more severe conditions and prognosis. Survival analysis indicated that the serum level of uric acid could strongly predict survival in IPAH patients with over time and those with a high level of uric acid had a worse prognosis.

Conclusion: The serum level of uric acid correlates significantly with patient conditions and prognosis in IPAH. And a higher serum level of uric acid predicts worse conditions and prognosis.