Background. Aging is a major risk factor for a range of chronic diseases. Oxidative
stress theory of aging has been previously proposed as one of the mechanisms responsible
for the age-related decline in organ/tissue function and the development of age-related
diseases. Urine contains rich biological information on the health status of every
major organ system and can be an important noninvasive source for biomarkers of systemic
oxidative stress in aging. Aims. The objective of this cross-sectional study was to
validate a novel panel of urinary oxidative stress biomarkers. Methods. Nucleic acid
oxidation adducts and oxidative damage markers of lipids and proteins were assessed
in urine samples from nondiabetic and currently nonsmoking subjects (n=198) across
different ages (20 to 89 years old). Urinary parameters and chronological age were
correlated then the biological age of enrolled individuals was determined from the
urinary oxidative stress markers using the algorithm of Klemera and Doubal. Results.
Our findings showed that 8-oxo-7,8-deoxyguanosine (8-oxoG), 8-oxo-7,8-dihydroguanosine
(8-OHdG), and dityrosine (DTyr) positively correlated with chronological age, while
the level of an F-2-isoprostane (iPF(2)alpha-VI) correlated negatively with age. We
found that 8-oxoG, DTyr, and iPF(2)alpha-VI were significantly higher among accelerated
agers compared to nonaccelerated agers and that a decision tree model could successfully
identify accelerated agers with an accuracy of > 92%. Discussion. Our results indicate
that 8-oxoG and iPF(2)alpha-VI levels in the urine reveal biological aging. Conclusion.
Assessing urinary biomarkers of oxidative stress may be an important approach for
the evaluation of biological age by identifying individuals at accelerated risk for
the development of age-related diseases.
