title: Variation of serum creatine kinase (CK) levels and prevalence of persistent hyperCKemia in a Norwegian normal population. The Tromsø Study.
abstract: In this cross-sectional study we assessed the prevalence of hyperCKemia, defined as persistent CK values ≥210 U/L in women, ≥400 U/L in men <50 years and ≥280 U/L in men ≥50 years (reference values according to the Nordic Reference Interval Project). Blood samples were obtained from 12,828 participants in the 6th survey of The Tromsø Study. We identified 686 (5.3%) individuals with incidentally elevated CK. After a standardized control test, 169 persons (1.3%) had persistent hyperCKemia, i.e. 69.9% normalization. Use of statins or other causes of hyperCKemia were detected in 78 individuals (46.2%), giving a prevalence of "idiopathic hyperCKemia" of 0.71%. CK variation was highest in younger men and in females between 60 and 69 years. This study has identified persistent hyperCKemia in 1.3% of the normal population, and demonstrates the importance of performing controlled CK analyses, also in those with identified risk factors.
authors: Department of Neurology and Neurophysiology, University Hospital of North Norway, Tromsø N-9038, Norway. hallvard.lilleng@unn.no
authors: Hallvard
authors: H
authors: Lilleng
authors: Karin
authors: K
authors: Abeler
authors: Stein H
authors: SH
authors: Johnsen
authors: Eva
authors: E
authors: Stensland
authors: Sissel
authors: S
authors: Løseth
authors: Rolf
authors: R
authors: Jorde
authors: Yngve
authors: Y
authors: Figenschau
authors: Sigurd
authors: S
authors: Lindal
authors: Tom
authors: T
authors: Wilsgaard
authors: Svein I
authors: SI
authors: Bekkelund