Effects of altitude on spleen volume: sonographic assessment

PURPOSE: To use sonography to determine changes that may arise in splenic volume in humans from regions of lower altitude who begin to live in regions of higher altitude. MATERIALS AND METHODS: The study was conducted in the Turkish province of A?ri, at an altitude of 1750 m and included 108 healthy, nonsmoking, disease-free volunteers who had moved from regions at an altitude lower than 500 m. Length, width, and thickness of the spleen were measured using sonography. Splenic volume was calculated using the following standard ellipsoid formula: length x width x thickness x 0.523. Sonographic assessments were repeated at 3 and 6 months along with other blood tests, including hemoglobin, hematocrit, and platelet levels. RESULTS: The mean +/- SD splenic volume was 299 +/- 97 cm(3) (range, 116-574 cm(3)). At 3 and 6 months, the splenic volumes decreased significantly compared to their initial values (p < 0.05). An increase in hemoglobin, hematocrit, and platelet count was observed in all subjects. CONCLUSION: Our data show that splenic volume in healthy individuals who begins to live at high altitudes decreases gradually.