Patients with high low-density lipoprotein cholesterol (LDLC) and asymptomatic high creatine kinase (CK) (>or=250 but <2500 IU/L, 10x the laboratory upper normal limit [UNL]) are often not started on statins or have statins stopped because of concern about myositis-rhabdomyolysis. In the current report, we prospectively examined the hypothesis that asymptomatic patients with high CK (>or=250 but <2500 IU/L) tolerate statins well at doses reducing LDLC to target, less than 100 mg/dL, without development of myalgia-myositis. We assessed outcomes of 3 groups of patients referred to us because of asymptomatic high CK (>or=250 but <2500 IU/L)--1 group (n = 29) on statins at referral and continued on statins, 1 group (n = 20) not on statins and started on statins, and 1 group (n = 19) not on statins and not given statins--all restudied 1 month after entry and then every 3 months. Of the 68 patients, 59 (87%) had CK greater than 1 to 3 times the UNL, 7 (10%) had CK greater than 3 to 5 times the UNL, and 2 (3%) had CK greater than 5 to 10 times the UNL. After 1.2 months of follow-up in 29 statin-->statin patients, median CK fell from 353 to 301 (P = .0018) and was 287 (P = .015) after 4 months. After 1.3 months of follow-up in 20 no statin-->statin patients, median CK fell from 397 to 292 (P = .0094) and was 419 after 4.1 months. After 1.1 months of follow-up in 19 no statin-->no statin patients, median CK fell from 392 to 323 (P = .14) and was 271 (P = .029) after 4.2 months. By repeated-measures analysis, there were no differences in entry CK among the 3 treatment groups; CK fell (P = .04) in the no statin-->no statin patients. Despite high baseline CK (48 patients with CK 1-5x the UNL, 1 with CK 5-10x UNL), no patients during follow-up on statins developed CK greater than 10 times the UNL (2500 IU/L), none discontinued statins or reduced statin dose because of myalgia-myositis, and there was no rhabdomyolysis. High pretreatment CK, particularly 1 to 5 times the UNL, should not be an impediment to start or continue statins to lower LDLC.