SHIFT WORKING IN THE CHILEAN ANDES (GREATER-THAN-3,600 M) AND ITS INFLUENCE ON ERYTHROPOIETIN AND THE LOW-PRESSURE SYSTEM

It was hypothesized that, in shift workers with a history of intermitt ent hypoxic stress (working 10 days at >3,600 m, then resting for 4 da ys at sea level) for >5 yr, the initial erythropoietin (EPO) response and the changes in central venous pressure (CVP) are different from th ose in Caucasian lowlanders. We studied the kitchen personnel (n = 11) of a mine (3,600 m) and a group of Caucasian lowlanders (n = 5). Bloo d samples were taken, and CVP was determined several times before, dur ing, and after a typical shift. At baseline data collection (BDC) befo re transition, the shift workers had EPO concentrations of 5.2 +/- 2.4 mU/ml, which increased at altitude (P < 0.01) and returned to BDC val ues on the recovery (day 16). The Caucasians showed the same time cour se. Serum transferrin receptor concentrations did not change in either group. CVP values were generally higher in the shift workers than in the Caucasians. In conclusion, the hypothesis that the initial EPO res ponse to a hypoxic stimulus is altered in these shift workers has to b e refuted. Higher hemoglobin concentrations and/or CVP values in shift workers might be responsible for the rather low EPO concentrations in shift workers at BDC.