Abstract
The clinical recognition of pulmonary arterial hypertension (PAH) is increasing, and with recent therapeutic advances, short-term survival has improved. In spite of these advances, however, PAH remains a disease with substantial morbidity and long-term mortality. The pathogenesis of PAH involves a complex interaction of local and distant cytokines, growth factors, co-factors, and transcription factors occurring in the right genetic and environmental setting. These factors ultimately lead to the detrimental changes in vascular anatomy and function seen in PAH patients. An important association between obesity/insulin resistance and PAH has recently been identified. Both conditions occur in the presence of a chronic low-grade inflammatory state, and although it is unlikely that a single pathway is solely responsible for the observed association, deficiencies in adiponectin, apolipoprotein E (ApoE) and peroxisome proliferator-activator receptor gamma (PPAR-γ) activity likely play a prominent role. Although incompletely understood, it is clear that further investigation is warranted and the role of weight loss and improved glycemic control in the treatment of at-risk patients with PAH and obesity should be determined.