HEMATOLOGICAL CHANGES OCCUR AFTER LONG-TERM MODERATE-ALTITUDE ADAPTATION
Brothers, M D., Nelson, J. L., Doan, B. K., Lorenz, M., Zupan, M. F., & Byrnes, W. C.,(2009). Altitude-related difference in hemoglobin mass and blood volumes upon acute exposure to moderate altitude. ACSM 56th Annual Meeting, Seattle, Washington. Presentation number 2365.
This study assessed acute differences in total hemoglobin mass plus erythrocyte, plasma, and total blood volumes between incoming sea-level (<300 m) and moderate-altitude (>1,800 m) male freshmen U.S. Air Force Academy cadets. It was hypothesized that moderate altitude Ss would have significantly more total hemoglobin mass, and erythrocyte, plasma, and blood volumes. Within 72 hours of moderate altitude exposure, a resting seated venipuncture (Hb concentration and hematocrit) and the optimized CO re-breathing protocol (total hemoglobin mass) were performed on incoming male freshmen (N = 56). Erythrocyte volume, plasma volume, and total blood volume were calculated utilizing total hemoglobin mass data, hemoglobin concentration, and hematocrit.
There were no differences in hemoglobin concentration between the two groups. Cadets from moderate altitude had significantly higher total hemoglobin mass, erythrocyte volume, and total blood volume. Plasma volume was not different.
Implication. Long-term (>2 years) residence at moderate altitude results in significant hematological acclimatization effects when compared to sea-level resident males of similar fitness levels.