Higher plasma levels of F₂-isoprostanes are associated with slower psychomotor speed in healthy older adults

Abstract

Oxidative stress has been identified as a process which is detrimental to brain health, and associated with age-related cognitive declines. Few studies to-date have examined the relationship between in vivo oxidative stress biomarkers and cognitive performance within healthy elderly populations. The current study investigated the relationship between reaction time and oxidative stress, as measured by blood plasma concentrations of F₂-isoprostanes using a sample of 251 healthy, non-demented, elderly volunteers (Male; 111: Female 140) aged 60–75 years from the Australian Research Council Longevity Intervention (ARCLI) study cohort. A Jensen Box was used in conjunction with the Hick paradigm in order to differentiate simple from choice reaction time (two, four and eight-choice conditions) as well as movement (MT) and decision times (DT). MT, but not DT, was found to be significantly slower for participants in the high F₂-isoprostane group compared to the low F₂-isoprostane group, across all stimulus choices. F₂-isoprostanes, age and Wechsler Abbreviated Scale of Intelligence (WASI) full scale intelligence quotient (IQ) were found to be significant predictors of average MT in the sample as a whole. These findings provide preliminary evidence to suggest that higher levels of oxidative stress may be associated with impaired psychomotor speed in the healthy elderly population.

Keywords:

• Aging
• isoprostanes
• oxidative stress
• processing speed
• psychomotor speed

Disclosure statement

The authors have no actual or potential conflict of interests to declare with respect to the research, authorship, and/or publication of this article.

Additional information

Funding

The study is funded by an Australian Research Council Discovery grant to Stough, Scholey and Croft, with additional funding to Stough from Horphag, Soho Flordis International-Research and Blackmores. The study was also supported by philanthropic grants from Doug Mitchell and Roderic O’Connor to Stough. Downey is supported by an NHMRC Career Development fellowship (APP1122577). Simpson and Nolidin are recipients of an Australian Government Postgraduate Research scholarship.