TY - JOUR T1 - Airwaves JF - Thorax JO - Thorax SP - 617a LP - 617a VL - 60 IS - 8 AU - Wisia Wedzicha Y1 - 2005/08/01 UR - http://thorax.bmj.com/content/60/8/617a.abstract N2 - In this issue of Thorax Aldashev et al remind us that high altitude pulmonary hypertension (HAPH) is an important public health problem, and that 140 million people live at an altitude above 2500 metres. The pathophysiology underlying HAPH is still poorly understood, but involves vascular remodelling. Phosphodiesterase (PDE) 5 is the major PDE found in pulmonary vasculature, and some earlier studies have suggested that it may have a role in pulmonary hypertension. The authors screened subjects in the mountainous Naryn region of Kyrgyzstan (altitude 2500–4000 m above sea level), and those with a raised pulmonary artery pressure were randomised to receive either the PDE5 inhibitor sildenafil at two dosages or placebo for 12 weeks. Patients receiving sildenafil at the lower dose showed a fall in pulmonary artery pressure and improvement in walking distance. The … ER -