Bioenergetic Effect of Pioglitazone in CLD-PH

Inclusion Criteria: * Provision of a signed and dated informed consent form * Stated willingness to comply with all study procedures for the duration of the study * Confirmed to have pulmonary hypertension (PH) due to chronic lung disease at screening * Pulmonary hypertension is defined based on meeting all three of the following measured at rest during the RHC: * Mean pulmonary artery pressure \>20 mmHg * Pulmonary artery wedge pressure ≤15 mmHg * Pulmonary vascular resistance \> 2 Wood units * Pulmonary hypertension is classified in Group 3: PH associated with lung diseases and/or hypoxia * Medications approved for the treatment of pulmonary hypertension must be at a stable dose for at least 30 days * Ability to take oral medication and be willing to adhere to the study intervention regimen * For females of reproductive potential: agreement to use highly effective contraception during study participation and for an additional 4 weeks after the end of study participation. * For males of reproductive potential: use of condoms or other methods to ensure effective contraception with a partner * Agreement to adhere to Lifestyle Considerations (below) throughout the study duration o During this study, participants are asked to arrive in the clinic for study visits in the fasting state. Specifically, participants should abstain from any caloric intake for 6 hours before arrival for the study visit. Exclusion Criteria: * Diabetes mellitus (type 1 or type 2), present within the preceding 1 year * Personal history of symptomatic hypoglycemia within 90 days preceding enrollment * Personal outpatient use of pioglitazone, rosiglitazone, metformin, insulin, or other medications for the indication of diabetes within 90 days preceding enrollment * History of left ventricular failure (systolic or diastolic) * Pulmonary hypertension due to Group 2 PH (PH due to left heart disease) * History of prior or active bladder cancer * Thrombocytopenia (diagnosis or known platelet count ≤120) within 90 days preceding enrollment * Platelet count ≤120 during screening or on the day of enrollment hypertension due to chronic lung disease * Cystic fibrosis * Pregnancy or lactation * Current tobacco use * Known allergic reaction to components of the study medication (pioglitazone) * Treatment with another investigational drug within 30 days