Abstract
Studies were made on 309 volunteers (156 males and 153 females) ranging from the age of 14 to 69. Their height, weight, chest thickness and skinfold thicknesses were measured anthropometrically. Total body potassium was estimated with a whole body gamma counter by counting gamma-rays from the naturally occurring radioisotopes of potassium-40. In the assessment of total body potassium content, it is necessary to make corrections for (1) chest thickness, (2) fat thickness of backside and (3) body width. The total error in estimating total body potassium content is within 2.5% in counting for 10 minutes with a whole body counter. Potassium content and concentration were compared with body indices, such as Bouchard's index, the body mass index, Rohrer's index, Broca's index and Minowa's index. Potassium content and concentration showed the sex difference and age trends. Potassium content in male was from 114.9 (g) to 217.6 (g) and that in female was from 80.0 (g) to 150.0 (g). Potassium content and concentration n male were higher than those in female. Both sexes showed a continuous decrease of potassium concentration with physiological aging. The correlation between potassium concentration and other body indices was high. The results demonstrated that potassium concentration was a useful index for assessing the degree of obesity. Total body potassium content can also be used in assessing the amount of lean tissue (fat free mass) of the body. The precision of the estimation of the lean body mass is of interest from the viewpoint of health control. The precision of the estimation of the lean body mass can be improved considerably by predicting the value of potassium concentration in unit lean body mass.
