Relationship between Serum Uric Acid Levels and the Severity of Pulmonary Hypertension.

Background: Right heart catheterization is the gold standard test for diagnosis and clinical assessment of the patients with pulmonary hypertension (PH). In recent years, the usefulness of cheaper and non-invasive tests in the follow-up of PH patients is being studied. The aim of the present study was to evaluate the relationship between serum uric acid level and severity of pulmonary hypertension in PH patients.

Materials and Methods: In a cross-sectional study, serum uric acid was measured in 110 patients with PH (63 women; mean age [±SD] was 52.83±17.88 years). Pulmonary arterial pressure and severity of right ventricular dysfunction were assessed using RHC and echocardiography, respectively.

Results: Serum uric acid was higher in PH patients with severe RV dysfunction, compared to mild and moderate dysfunction (7.8mg/dl [IQR: 5.8-9.2] in severe dysfunction, versus 4.7 mg/dl [3.87-5.82] in mild dysfunction and 5 mg/dl [3.5-6.95] in moderate dysfunction. Serum uric acid was significantly correlated with pulmonary artery systolic pressure (r=0.51, P<0.001). Serum uric acid level also had a significant positive correlation with the World Health Organization functional class of the patients (r=0.49, P<0.001). Serum uric acid level greater than 5.7 mg/dl was found to be the most sensitive and specific points for predicting severe RV dysfunction in PH patients (sensitivity 76.6%, specificity 71.4%; AUC=0.79, P<0.001) .

Conclusion: Serum uric acid is correlated with the severity of symptoms and RV dysfunction in patients with pulmonary hypertension. Further studies are recommended with larger sample size in this regard.