OBJECTIVETo study the hemoglobin status of children under the age of three years and the prevalence of anemia at high altitude.

METHODSCross-sectional study and randomly sampling were used. Blood was collected on tip of finger and the level of hemoglobin was measured using B-Hemoglobin photometer. We adjusted the hemoglobin based on altitude, using three methods of CDC, Direen's and Dallman's and then estimated the prevalence of anemia.

RESULTS(1) 1 127 children were examined. The findings indicated that the average hemoglobin was about 120 g/L. There was no significant difference for Hb between boys and girls. Urban children had a higher hemoglobin level (123.3 g/L) than rural children (119.9 g/L). Analysis of covariance indicated that, after controlling the factor of altitude, the mean content of hemoglobin of rural children was lower than that of urban children and hemoglobin varied among districts. (2) Different method used for correction of hemoglobin caused different prevalence rates of anemia but they were higher than un-corrected prevalences: 90.4% for CDC method, 72.3% for Dirren's method and 65.0% for Dallman's method respectively.

CONCLUSIONHigher altitude seemed to affect the levels of hemoglobin significantly. The prevalence of anemia in children might be higher, but current hemoglobin correction methods might not be suitable for correcting hemoglobin of Tibetan children. So we suggested that it was imperative to establish a relationship between altitude and hemoglobin of Tibetan children.