Atrial natriuretic peptide and red cell 2,3-diphosphoglycerate in patients with chronic mountain sickness

Abstract

Background. - Individuals with chronic mountain sickness (CMS) show severe hypoxemia, excessive polycythemia, and marked pulmonary hypertension. The pathophysiologic mechanisms of CMS are still not completely understood. Methods. - We determined plasma atrial natriuretic peptide (ANP), red cell 2,3-diphosphoglycerate (2,3-DPG), hematocrit, hemoglobin, and arterialized ear lobe blood gas values in 13 patients with CMS (9 Hans, 4 Tibetans) and 18 control Han Chinese men of similar age, height, and weight who had been living at 4300 m on the Tibetan plateau of Qinghai Province, China, for approximately 14 years. Results. - A significantly higher level of ANP was found in the CMS patients compared to the non-CMS patients (113.4 ± 5.5 pg/mL vs 87.6 ± 4.7 pg/mL, P < .01), and the levels of ANP correlated positively with the hemoglobin concentration (r = 0.8282, P < .01), and the 2,3-DPG concentrations in the CMS patients were negatively correlated with their PaO2 values (r = -0.7898, P < .01). The CMS patients had significantly higher PaCO2 levels, lower pH values, lower PaO2 levels, and greater alveolar-arterial oxygen differences (PaO2 - PaO2) compared to the non-CMS subjects. Conclusions. - These findings suggest that overproduction of ANP and 2,3-DPG at high altitudes may play an important role in the pathophysiology of chronic mountain sickness.