Levels of uric acid may predict the future development of pulmonary hypertension in systemic lupus erythematosus: a seven-year follow-up study

Abstract

OBJECTIVE: The objective of this paper is to assess whether pulmonary hypertension (PH) may be detected at one point in time or longitudinally predicted by serum uric acid (sUA) levels in systemic lupus erythematosus (SLE). METHODS: We conducted a post-hoc analysis of a long-term followed cohort of Mexican SLE patients. Echocardiography-based definitions of PH by the ESC/ERS/ISHLT and its associations with clinical and laboratory data on enrollment were studied. Especially, the impact that sUA levels at baseline may have on the future development of PH in patients with normal pulmonary artery systolic pressure (PASP) was explored. RESULTS: Out of the 156 SLE patients originally enrolled in the cohort, 44 met the inclusion criteria for the present study and were grouped as having (n =10) or not having (n = 34) PH. At baseline, sUA levels of 5.83 ± 1.79 and 5.82 ± 1.97 mg/dl (p = ns) were found in patients with and without PH, respectively. No association between PASP and other markers was found. In patients with normal PASP, the presence of sUA ≥ 7 mg/dl at baseline predicted future development of PH (relative risk 8.5, 1.0009 to 72; p = 0.04). CONCLUSION: In SLE, sUA levels at one point in time are useless to detect PH. However, steady hyperuricemia may predict the future development of PH in patients with normal PASP at baseline.