Creatine Phosphokinase Activity in Blacks vs Whites

Abstract

To the Editor.— Olerud and associates reported that black marine recruits who developed acute exertional rhabdomyolysis (AER) had significantly higher peak serum creatine phosphokinase (CPK), lactic dehydrogenase (LDH), SGOT, and myoglobin levels than non-blacks who developed AER. The overall incidence of AER in blacks was not significantly different from that of non-blacks. Olerud et al stated there was no clear explanation for the differences between black and non-black recruits. 1 However, several studies from this laboratory are relevant to their findings. We have reported that baseline serum CPK activity is significantly higher in black men and women than in white men and women, respectively. 2,3 Olerud et al did not report the preexercise serum CPK levels of their recruits, but it would be surprising if they failed to observe this black-white difference that we have also found in analysis of unpublished data from over 1,000 pre-employment physical examination subjects. We