Age dependence of renal function: clearance of iohexol and p-amino hippurate in healthy males

Research output: Contribution to journalArticle


Iohexol, a newly developed non-ionic contrast agent, has been recently documented as a reliable glomerular filtration marker. This study describes the age dependence of the single injection clearance of iohexol in a sample of healthy male volunteers ranging from 21 to 77 years of age. In parallel, renal plasma flow was studied by measuring the total clearance of p-amino hippuric acid administered as a continuous infusion. In subjects older than 50 years a negative correlation to age was found for both p-amino hippuric acid and iohexol clearance, with a reduction of 52 ml/min and 12 ml/min per decade, respectively, whereas no age dependence was found for younger subjects. Correlation between p-amino hippuric acid and iohexol clearances was 0.81. However, the filtration fraction, defined as the ratio of iohexol to p-amino hippuric acid clearance, was higher in the elderly subjects. A consistent discrepancy was found between total and renal clearances of p-amino hippuric acid, indicating significant renal metabolism. Renal clearance of creatinine was poorly correlated to iohexol clearance and did not show any relationship to age.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Infectious Medicine
  • Pharmacology and Toxicology
  • Medicinal Chemistry


  • iohexol clearance, p-amino hippurate clearance, renal plasma flow, creatinine clearance, glomerular filtration rate, aged, age dependence
Original languageEnglish
Pages (from-to)641-646
JournalScandinavian Journal of Clinical & Laboratory Investigation
Issue number7
Publication statusPublished - 1989
Publication categoryResearch

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Division of Infection Medicine (SUS) (013008000), Division of Clinical Chemistry and Pharmacology (013250300)