ELEVATED SERUM CK IN LONG ABSTINENT COCAINE ABUSERS

In preparation for an exercise program in cocaine abusers maintained a bstinent in a hospital setting (average 98.4 days), we measured restin g serum creatine kinase (CK). Surprisingly, many were elevated. Furthe r tests confirmed the observation. We measured 19 long abstinent cocai ne abusers, 22 abstinent abusers of other substances, and a later grou p of 26 long abstinent cocaine abusers. While none of the other substa nce abusers showed elevated serum CK levels, 53 and 31 % of the abstin ent cocaine groups did (p = .000082 and .00041, respectively). All CK elevations were muscle derived; repeated sampling demonstrated stabili ty. Cocaine abusers' CK showed a bimodal distribution: the lower bell curve approximated controls and the higher bell curve centered above n ormal range, at 400 U/L. Demographics did not influence the results. W ith complementary findings of impaired spatial motor performance, thes e persistent CK elevations suggest that a large minority of cocaine ab users maintain tendencies to coarse motor control and impulsive moveme nts, and perhaps hyperactivity.