Total body potassium and body cell mass from infancy through childhood and adolescence: gender differences and percentiles distribution.

Objective: This investigation provides information about changes of TBK and BCM during growth from infancy to adolescence inclusive. Methods: Compilation of results from several semi-longitudinal studies of 476 males and 528 females were accomplished on Caucasian children. Results: TBK and BCM were slightly higher in boys who were also taller and heavier from infancy to about 12 years of age. TBK and BCM were significantly different at P < 0.05 level in favor of boys at ages 13 to 15 years and at P < 0.01 level at ages 16 to 18 years compared to girls of the same age periods. Points of acceleration of BCM -- TBK during adolescence of both genders were found using regression with intersection of two-lines analyses, which occurred when boys reached height of 139.9 cm compared to 128.8 cm in height of girls. Conclusions: TBK percentile tables of both genders based on semi-longitudinal approach can be used objectively for evaluations of BCM using Wang's formula BCM(Kg) = TBK(g) × 9.20/39.1 compared to Moore's equation BCM(gr) = Ke(mEq) × 8.33 which underestimates BCM. [ABSTRACT FROM AUTHOR]