Insulin resistance is a key mechanism in metabolic disorders, which has also been implicated in the development of pulmonary hypertension. In this pilot study, the investigators´ goal is to directly determine insulin sensitivity in idiopathic pulmonary arterial hypertension patients and to compare the results with data from healthy controls.

Inclusion Criteria:

• signed informed consent form
• patients with idiopathic or hereditary pulmonary hypertension / healthy controls

Exclusion Criteria:

• premenopausal women
• other relevant lung disease
• relevant left heart disease
• untreated systemic hypertension
• Diabetes mellitus
• pulmonary hypertension other than idiopathic or hereditary form

Healthy controls, or patients with idiopathic or hereditary pulmonary hypertension