title: [Value of muscle enzyme analysis in differential diagnosis of childhood myopathic hyper-creatine kinase-emia].
abstract: OBJECTIVE
  To summarize the etiology and clinical characteristics of children with myopathic elevated creatine kinase (CK) levels. The degrees of elevated CK as well as lactic dehydrogenase (LDH) and aspartate aminotransferase (AST) levels in different myopathy were analyzed.
  
  
  METHODS
  The clinical data of 235 cases characterized as myopathic hyper-CK-emia from January 2004 to December 2011 were collected and analyzed. A retrospective analysis of LDH and AST levels according to CK in part of the patients were reviewed.
  
  
  RESULTS
  Of the 235 cases, 180 were male and 55 female. According to the age at which hyper-CK-emia was diagnosed, 64 cases were under 6 months, 90 between 6 months and 3 years, 50 between 3 and 6 years and 31 between 6 and 14 years. Their CK levels significantly increased in 162 cases, moderately increased in 31 cases, and slightly increased in 42 cases. The age at which hyper-CK-emia was diagnosed and the CK level had no correlation with muscle weakness and the severity. As to CK levels: Duchenne muscular dystrophy (DMD) > inflammatory myopathies > congenital muscular dystrophy (CMD) > metabolic myopathies. LDH and AST levels: DMD > inflammatory myopathies > metabolic myopathies > CMD.
  
  
  CONCLUSIONS
  Unlike adults, the etiology of myopathic hyper-CK-emia in children is complicated and diverse. The onset type, the degree and duration of hyper-CK-emia are helpful to make the diagnosis. CK increases most significantly in DMD, then in inflammatory myopathies, CMD, and metabolic myopathies. Diagnostic flowchart of myogenic hyper-CK-emia should follow a certain process, and the indications of biochemical tests, metabolic screening, electrophysiological examination, muscle biopsy and genetic testing should be made. Finally, different treatments should be designed according to the etiology.
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Mao
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xiong
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Jiao
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Cui-jie
authors.initials: CJ
authors.lastname: Wei
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Ding
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Xing-zhi
authors.initials: XZ
authors.lastname: Chang
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Yan-ling
authors.initials: YL
authors.lastname: Yang
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Xue-qin
authors.initials: XQ
authors.lastname: Liu
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Yong-hong
authors.initials: YH
authors.lastname: Chen
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Jun-bao
authors.initials: JB
authors.lastname: DU
authors.affiliation: Department of Medical Statistics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Xue-ying
authors.initials: XY
authors.lastname: Li
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Yu-wu
authors.initials: YW
authors.lastname: Jiang
authors.affiliation: Department of pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Jiong
authors.initials: J
authors.lastname: Qin
mesh_terms: D000293:Adolescent; D001219:Aspartate Aminotransferases / Q000032:analysis; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D003402:Creatine Kinase / Q000032:analysis*; D003937:Diagnosis, Differential; D005260:Female; D005820:Genetic Testing; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D008297:Male; D009135:Muscular Diseases / Q000201:enzymology*; D020388:Muscular Dystrophy, Duchenne; D012189:Retrospective Studies
chemical_list: D007770:L-Lactate Dehydrogenase; D001219:Aspartate Aminotransferases; D003402:Creatine Kinase