CPK levels in children and adolescents vary according to age, sex, weight and whether they are taking contraception

Between 2011 and 2016, 5,238 blood samples from 2,707 healthy children and adolescents, aged 0.14 months to 18 years, were collected as part of the German LIFE-Child longitudinal study, which aims to document the development of a healthy child from birth to early adulthood.

• CPKEnzyme contenue dans les cellules musculaires, qui est libérée dans le sang en cas d’atteinte musculaire. levels rise sharply during the first year of life in both boys and girls, peaking shortly after the age of one.
• It then declines until the age of three, reaching a plateau between the ages of five and nine, with boys’ values higher than girls’.
• From the age of nine onwards, CPK levels begin to diverge: in boys, they rise more sharply at the onset of puberty, reaching 14.48 µkat/L at the age of 18, while in girls, the level is only 5.74 µkat/L.
• The use of oral contraceptives, extreme thinness, thinness or obesity are inversely correlated with CPK levels.

The authors recommend the use of age- and sex-specific reference values when measuring CPK in children and adolescents.

Creatine kinase serum levels in children revisited: New reference intervals from a large cohort of healthy children and adolescents. Fechner A, Willenberg A, Ziegelasch N et al. Clin Chim Acta. 2024 May 11;560:119726.