Reduction of erythrocyte magnesium concentration in heterozygote beta-thalassaemic subjects and in normal subjects submitted to physical stress.

Erythrocyte and serum magnesium (Mg) concentrations have been assayed in a group of sedentary heterozygote beta-thalassaemic subjects (beta-thal), in a group of non-thalassaemic well trained runners before and after a 25 km running race, and in a group of sedentary healthy controls. The mean erythrocyte Mg concentration (EMg) found in beta-thal (2.72 mEq/litre) and in runners, both before and after the race (2.58 mEq/litre before, 3.10 after), was significantly lower than the EMg values from the control group (3.69 mEq/litre). We propose various hypotheses to explain the reductions observed.