PDK1 and pulmonary arterial hypertension: Similar results were obtained under hypoxic conditions: the mRNA levels of PDK1 and PDHA1 were significantly increased in PAH-PASMCs compared with non-PAH-PASMCs by 4.3-fold (p < 0.05) and 2.3-fold (p < 0.05), respectively (Figure 1A,B).