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

Summary, in English

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.

• Author: S E Back; Bengt Ljungberg; Ingrid Nilsson-Ehle; O Borga; Peter Nilsson-Ehle
• Department/s: Infection Medicine (BMC); Division of Clinical Chemistry and Pharmacology
• Publishing year: 1989
• Language: English
• Pages: 641-646
• Publication/Series: Scandinavian Journal of Clinical & Laboratory Investigation
• Volume: 49
• Issue: 7
• Links: http://dx.doi.org/10.3109/00365518909091539
• Document type: Journal article
• Publisher: Informa Healthcare
• Topic: Infectious Medicine; Pharmacology and Toxicology; Medicinal Chemistry
• Keywords: iohexol clearance; p-amino hippurate clearance; renal plasma flow; creatinine clearance; glomerular filtration rate; aged; age dependence
• Status: Published
• ISBN/ISSN/Other: ISSN: 1502-7686