Serum iron, copper, zinc, ferritin, and ceruloplasmin after intense heat exposure

Summary

Twelve voluntary adult subjects twice took a 30-min sauna bath, at a temperature of 80‡ C with a 30-min rest between each, every 12 h for 1 week. Measurements of serum iron, copper, zinc, ferritin and ceruloplasmin were performed before the experiment, after the first and second 30 min in the sauna and at the end of the week. The first two sauna baths did not significantly change the concentrations of the trace elements measured. After the week the mean serum copper concentration had decreased from 15.0 (SD 1.7) Μmol·l⁻¹ to 13.5 (SD 2.0) Μmol·l⁻¹ (p<0.02). The mean zinc concentration decreased from 13.8 (SD 2.4) Μmol·l⁻¹ to 9.8 (SD 1.8) Μmol·l⁻¹ (p<0.001) during the week of the experiment. At the beginning of the study period two subjects had zinc concentrations below the reference values and after the week nine subjects had zinc concentrations below the reference values. The concentration of serum ferritin decreased from 142.2 (SD 103) Μg·l⁻¹ to 111.3 (SD 89) Μg·l⁻¹ (p<0.02) whereas the values of ceruloplasmin remained unchanged. Our findings confirm the earlier suggestion that heavy exposure to heat can cause a loss of some trace elements, especially zinc.