Hyperuricemia is strongly associated with pulmonary hypertension in chronic lung disease

Abstract

Hyperuricemia has been identified as a powerful predictor of World Health Organization (WHO) group 1 pulmonary hypertension (PH) (pulmonary arterial hypertension). However, its relationship with PH secondary to chronic lung diseases (WHO group 3) remains unclear. Demographic, clinical, laboratory, lung function, and right heart catheterization data were retrospectively collected for 323 patients with various severe chronic pulmonary diseases undergoing evaluation for lung transplantation at a tertiary university medical center from June 2017 to February 2023. The data were analyzed to identify associations between hyperuricemia (serum uric acid level >6 mg/dL) and PH [mean pulmonary arterial pressure (MPAP) >20 mmHg]. Compared to the normouricemia group (n=211), patients with hyperuricemia (n=112) exhibited a higher likelihood of being younger (P=0.02), male (P<0.001), presenting with PH (P=0.001) and severe PH (MPAP >35 mmHg; P<0.001). They had elevated values of body mass index (P=0.004), plasma N-terminal pro-B-type natriuretic peptide (P<0.001), serum creatinine (P<0.001) and C-reactive protein (P=0.03). The following variables were significantly associated with PH: higher values of body mass index (P=0.005), uric acid (P<0.001), total lung capacity (P=0.02), residual volume (P=0.01), and pulmonary capillary wedge pressure (P<0.001); shorter 6-minute walk test distance (P=0.005); and lower forced expiratory volume in one second (P=0.006) and diffusing lung capacity for carbon monoxide (P<0.001). On multivariate analysis, elevated uric acid level remained one of the variables most significantly associated with PH (OR 1.29, 95% CI 1.05-1.58, P=0.01). In conclusion, in patients with severe chronic lung diseases, hyperuricemia is strongly associated with the presence of PH.