A longitudinal study of total body potassium in normal breastfed and bottle-fed infants

Area of Science:

• Biophysics
• Human Physiology
• Pediatric Growth

Background:

• Previous research predicted distinct growth patterns for total body potassium (TBK) based on length.
• A difference in the semilog function slope was hypothesized between infants and children aged 3-18 years.

Purpose of the Study:

• To validate the hypothesis that infant growth, measured by total body potassium (TBK) and length, follows a unique semilog function.
• To establish a regression model for TBK and length in infants.

Main Methods:

• Analysis of data from 84 infants with at least three measurements within their first year of life.
• Application of semilog function to compare total body potassium (TBK) versus length.
• Development of a regression line to describe the relationship between TBK and length.

Main Results:

• Data from 84 infants supported the hypothesis of differing growth patterns.
• A specific regression line was established: loge K, g = -0.265 + 0.04112 length in centimeters.
• The findings indicate a unique allometric scaling of TBK with length in early human development.

Conclusions:

• The study confirms that total body potassium (TBK) growth in infants is accurately described by a semilog function of TBK versus length.
• The established regression model provides a quantitative measure for infant growth assessment.
• This validates the distinct physiological growth trajectory of infants compared to older children.