EFFECTS OF AGING ON ANTIPYRINE CLEARANCE - PREDICTIVE FACTORS OF METABOLIZING CAPACITY

The purpose of this study was to identify variables that can account f or the decline of antipyrine clearance (Cl-AP) in elderly adults and t hat may help predict a reduction in metabolizing capacity, For compari son, Cl-AP was determined in 177 elderly (mean age 82 years) and 25 yo ung (mean age 29 years) volunteers. Antipyrine (1 g) was administered orally and Cl-AP was determined by the one-sample saliva method. Mean Cl-AP was reduced by 38% and antipyrine half-life increased by 64% in old subjects. Multiple regression analysis of Cl-AP revealed an indepe ndent value for age, serum aspartate transaminase (AST), and height in the elderly. The independent variables collectively accounted for 27% of the variance explained, Age, high serum AST, use of diuretics, and no consumption of drugs known to stimulate oxidative metabolism were selected by multivariate analysis (logistic model) as independent pred ictors of a low metabolizing capacity. The findings indicate that fact ors other than age may contribute to impaired hepatic oxidative metabo lism in the elderly.