Priscilla C. King

The relation of total body potassium to height, weight, and age in normal adults

Total body potassium was measured in 103 healthy adults using a shadow-shield whole-body monitor of high sensitivity. The range of height was 147 to 192 cm, of weight 43 to 92 kg, and of age 18 to 77 years. The values obtained for total body potassium were correlated with height, with weight, and with height and weight. Age was then included as an additional variable. The standard deviation from regression was smaller when total body potassium was correlated with height than with weight and was further reduced, to about 9%, in a multiple regression using height and age. The advantages of this relationship over indices involving weight are discussed. The smallest standard deviation from regression, 7·5%, was obtained when total body potassium was correlated with height, weight, and age. The usefulness of this relationship is discussed with comment on its limitations. A regression equation was derived between lean body mass (derived from height and weight) and total body potassium with a standard deviation from regression of 5·5% in males and 7·3% in females.

Absorption of Cyanocobalamin, Coenzyme B12, Methylcobalamin, and Hydroxocobalamin at Different Dose Levels

The whole body retention of radioactive cyanocobalamin, coenzyme B12, methylcobalamin, and hydroxocobalamin was measured by whole body monitoring after oral doses of 1, 5 and 25 μg. At each dose level there were significant differences between the values for whole body retention of the different cobalamins.

The Relationship between Total Body Potassium and Exchangeable Body Potassium Measured at 24 Hours and 44 Hours after Administration of 43K

Abstract. Total body potassium was measured in patients by whole‐body monitoring and compared with exchangeable body potassium measured 24 h and 44 h after administration of 43K. It was confirmed that equilibration was incomplete after only 24 h but, when the 44 h exchangeable potassium was expressed as a percentage of the total body potassium or as mEq per kilogram body weight, the mean values for males and females were not significantly different from the corresponding values found here and by other workers at 24 h post‐administration. However, in a hypokalemic patient treated with carbenoxolone sodium, the exchangeable potassium did not accurately reflect the total body potassium before and after treatment or when the patient was normo‐kalaemic. The measured values of total body potassium were also compared with normal values estimated from the patients weight, height and age, and from height and age only. The importance was demonstrated of using a relationship which does not involve the patients weight when aberrations in body weight may exist, in this case obesity. The longer half‐life and lower radiation per μCi of 43K was advantageous but the isotope is not readily available and is more expensive than 42K because of its method of production.