A predictor for total body potassium in man based on height, weight, sex and age: applications in metabolic disorders.

Abstract

Abstract The potassium levels of 881 normal adults measured at Brookhaven were used to derive a single comprehensive formulation which expresses expected body potassium (KP = α W12 H2) as a function of age, weight, height, and sex. The α-term is defined to reflect changes with sex and age. The means of the ratios of body potassium/predicted potassium for the BNL adults (20 to 64 years) were 1.007 ± 0.069 for males, and 0.993 ± 0.063 for females. The potassium data obtained at the St. Luke Medical Center for an additional 2,522 normal subjects (1,714 children and 808 adults) were analyzed using the BNL formulation. The mean ratios were 1.000 ± 0.103 for males, and 0.987 ± 0.102 for females, where the ages range from 4 to 79 years. Large variations in total body potassium were found in the 231 patients compared against the normal expected potassium value. Four disease groups had mean potassium ratios greater than 5 per cent above normal, while 8 disease groups had mean potassium ratios more than 5 per cent below normal. Individual potassium ratios varied from 1.4 in an acromegalic patient to as low as 0.64 in a disuseosteoporotic patient. The additional parameters of total body water and/or intracellular water may provide further refinement in the interpretation of total body potassium data.