Urinary tetrahydrocortisone and tetrahydrocortisol glucosiduronates in normal newborns, children and adults

Abstract

Abstract. Utilizing a simple, highly specific radioimmunoassay (RIA), we measured the excretion of the glucosiduronate conjugates of tetrahydrocortisone (THE-gluc) and tetrahydrocortisol (THF-gluc) in adults (n = 16), children (n = 58) and newborns (n = 5), in order to establish a normal range of values for age and surface area. Both tetrahydrometabolites showed a linear inrease with age but became constant for all individuals except newborns when results were calculated per square meter. Newborns excreted disproportionately low levels of these metabolites for their size. In children of similar ages, when 24h urine collections (n = 13) were compared to spot AM specimens (AM-Sp) (n = 45) in which the daily volume was estimated by creatinine excretion, THE-gluc/m2 levels were significantly higher in AM-Sp urines but THF-gluc/m2 levels were similar. Levels of both metabolites were markedly elevated in two patients with hyperadrenal states and low in three patients with hypoadrenal states compared to normal values per m2. These results indicate that the RIA for THE-gluc and THF-gluc can be a useful indirect test of cortisol secretion in children as well as in adults. Although 24h urine collections are more accurate, creatinine corrected AM-Sp urines may be clinically useful when values of these metabolites per m2 are compared to appropriate controls.