The results of detection of the expression of cytokines (VEGF, ET, NO, and SOD) showed that compared with the normal control group, the expressions of ET-1 and VEGF were increased, whereas the expressions of NO and SOD were decreased in the OSAHS-associated PHT group (all P < .05) (Table 3). Here, SOD1 is linked to pulmonary hypertension, primary, 1.