Total Body Potassium in Normal Children

Autor: Margaret A. Flynn, Jack Clark, Gerald R. Chase, Calvin Woodruff
Rok vydání: 1972
Předmět:
Zdroj: Pediatric Research. 6:239-245
ISSN: 1530-0447
0031-3998
DOI: 10.1203/00006450-197204000-00005
Popis: Extract: Normative data for total body potassium on 462 children (232 boys and 230 girls) are presented. The regression of total body potassium on weight can be described as a straight line for males (grams K = 4.32 + 2.12 × weight) and two significantly different lines for females (grams K = −1.50 + 2.32 × weight for weight ≤ 30 kg, and grams K = 34.90 + 1.11 × weight for weight > 30 kg), with less potassium per kilogram for females weighing more than 30 kg. No sex-related difference is found between 12 and 30 kg. When the regression of total body potassium on height is examined, it is found that a logarithmic transformation of potassium values results in a similar pattern, with no sex-related differences between 100 and 135 cm and less potassium per centimeter in females over this height. For males, log K in grams = 1.761 + 0.0182 × cm of height; and for females, log Kin grams = 1.595 + 0.01942 × cm for height ≤ 135 cm, and log K in grams = 2.574 + 0.01215 × cm for height > 135 cm. The logarithmic transformation of K versus height is proposed as a standard because it reflects changes in slope associated with known physiologic and endocrinologic changes occurring with puberty and may be more sensitive than weight in predicting abnormal values in individual patients. Speculation: Since the regression of total body potassium on height appears to be a straight line common to both sexes 100–130 cm tall, with a diverging line indicating progressively less potassium per centimeter for females over 135 cm in height, these data were compared with available data for infants. The total body K values of infants between 50 and 80 cm in length appear to fall on a line with a steeper slope than values of children 100 to 135 cm tall. This observation suggests that, during the 1st year of life, increasing total body potassium per centimeter of length reflects maturation of body composition. Further extension of such observations to low birth weight infants might be expected to give information on their body composition.
Databáze: OpenAIRE
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