Factors affecting serum creatine phosphokinase levels in the general population: The role of race, activity and age

The serum creatine phosphokinase (CPK) levels of newly admitted and hospitalized Negro and Caucasian psychiatric patients are presented. Significantly higher levels of serum CPK activity were found in Negro males and females, as compared to Caucasian males and females, in admission samples, in random samples from the late period of hospitalization, and in the mean serum CPK levels throughout hospitalization. There were no significant differences between serum CPK levels at admission and in samples chosen at random from the last two weeks of hospitalization. The serum CPK levels of males tended to peak between the ages of 10-19 and 40-49.