title: Cumulative incidence and risk factors of creatine kinase elevation associated with telbivudine.
abstract: OBJECTIVE
  An increasing number of studies are reporting a high frequency of creatine kinase (CK) elevation during telbivudine therapy; however, few reports have focused on the cumulative incidence and risk factors of CK elevation. This study was performed to investigate the cumulative incidence and risk factors of CK elevation in Chinese patients treated with telbivudine.
  
  
  METHODS
  In this observational study, patients with chronic hepatitis B receiving telbivudine therapy between July 2008 and December 2013 were enrolled. The cumulative incidence of CK elevation was analyzed using the Kaplan-Meier method combined with the log rank test. Risk factors were determined using Cox proportional hazards regression models.
  
  
  RESULTS
  A total of 207 eligible patients were analyzed. The cumulative incidence of CK elevation at 12, 24, 36, 48, 60, and 72 months was 51.2 %, 68.9 %, 75.1 %, 78.1 %, 78.1 %, and 78.1 %, respectively. Multivariate analysis revealed that male and lower baseline estimated glomerular filtration rate (eGFR) were significant risk factors for CK elevation.
  
  
  CONCLUSIONS
  The cumulative incidence of CK elevation after long-term telbivudine use is quite high, and gender and baseline eGFR may be useful predictors. However, when combined with regular monitoring of CK levels, especially for patients with lower eGFR, telbivudine is a relatively safe nucleoside analog treatment for chronic hepatitis B.
authors.affiliation: Department of Pharmacy, HuaShan Hospital, Fudan University, No. 12 Middle Wu Lu Mu Qi Road, Shanghai, 200040, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.affiliation: College of Pharmacy, Fudan University, Shanghai, China.
authors.forename: Cai
authors.initials: C
authors.lastname: Cheng
authors.affiliation: Department of Pharmacy, HuaShan Hospital, Fudan University, No. 12 Middle Wu Lu Mu Qi Road, Shanghai, 200040, China.
authors.forename: Bicui
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Pharmacy, HuaShan Hospital, Fudan University, No. 12 Middle Wu Lu Mu Qi Road, Shanghai, 200040, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Infectious Diseases, HuaShan Hospital, Fudan University, No. 12 Middle Wu Lu Mu Qi Road, Shanghai, 200040, China. jmzhang@vip.126.com.
authors.forename: Jiming
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Pharmacy, HuaShan Hospital, Fudan University, No. 12 Middle Wu Lu Mu Qi Road, Shanghai, 200040, China. wangbin@huashan.org.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000009:adverse effects*; D003402:Creatine Kinase / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D019694:Hepatitis B, Chronic / Q000097:blood / Q000188:drug therapy; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012737:Sex Factors; D000077712:Telbivudine; D013936:Thymidine / Q000009:adverse effects / Q000031:analogs & derivatives*; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D000077712:Telbivudine; D003402:Creatine Kinase; D013936:Thymidine
keywords: Creatine kinase elevation; Cumulative incidence; Risk factors; Telbivudine