Individuals with PAH had a higher mean serum urea (39.3 vs. 33.9 mg/dL, p < 0.0001), creatinine (0.824 vs. 0.735 mg/dL, p = 0.0001), uric acid (5.93 vs. 5.32 mg/dL, p < 0.0001) and cystatin C (1.11 vs. 0.939 mg/dL, p < 0.0001) levels, consistent with the higher rate of diagnosis of chronic kidney disease in that population when compared to controls. This evidence concerns the gene CST3 and pulmonary arterial hypertension.