Urinary 8-Hydroxy-2-deoxyguanosine and Cognitive Function in Puerto Rican Adults

摘要

DNA oxidative stress has been suggested as an important pathogenic mechanism in cognitive impairment andndementia. With baseline data collected from 2004 to 2008, the authors examined whether urinary 8-hydroxy-2-ndeoxyguanosine (8-OHdG), a biomarker of global DNA oxidation, was associated with cognitive function in a sam-nple of 1,003 Puerto Rican adults, aged 45–75 years, living in Boston, Massachusetts, and the surrounding area.nCognitive function was measured by using a battery of 7 tests: the Mini-Mental State Examination, word listnlearning, digit span, clock drawing and figure copying, Stroop, and verbal fluency tests. The primary outcomenwas a global cognitive score, averaging standardized scores across all cognitive tests. A higher 8-OHdG concen-ntration was significantly associated with lower global cognitive scores, after adjustment for age, education, status ofnthe gene for apolipoprotein E (APOE), and other covariates (Ptrend ¼ 0.01). The difference in the global score,ncomparing participants in the 2 extreme 8-OHdG quartiles, was u00010.11 (95% confidence interval: u00010.20, u00010.02),nwhich was equivalent to accelerating cognitive aging by about 4 years, as observed in this population. Prospectivenstudies are needed to elucidate whether elevated urinary 8-OHdG concentrations can predict the rate of cognitivendecline and incident dementia.