Novel Associations of F2-Isoprostanes, F3- Isoprostanes and Isofurans in Older Adults with Chronic Fatigue Syndrome: An Exploratory Study

Plasma levels of F 2 -isoprostanes (F 2 -IsoPs), a whole body oxidative stress marker, have been noted to be elevated in populations with chronic fatigue syndrome (CFS).We hypothesized that the oxidative stress biomarkers of F 2 -isoprostanes (F 2 -IsoPs), isofurans (IsoFs) and F 3 -isoprostanes (F 3 -IsoPs) are related to hypothalamic-pituitary-adrenal (HPA) axis dysregulation in chronic fatigue syndrome (CFS) subjects assessed by plasma dehydroepiandrosterone (DHEA) and cortisol and gene expression of sirtulin-1 (SIRT1).Plasma samples were obtained from nine CFS individuals aged 65 years or older.The mean levels of plasma F 2 -IsoPs (M=178 pg/ml, SD=100) and IsoFs (M=266 pg/ml, SD=205) were several-fold higher than previously reported in healthy subjects.F 2 -IsoPs:F 3 -IsoPs and SIRT1 were negatively associated (r=-.674,p<.05) whereas F 3 -IsoPs were inversely correlated with DHEA (r=-.586,p<.05) and positively associated with SIRT1 (r=.733, p<.05).After correction for age and sex, the F 2 -IsoPs:IsoFs ratio was positively correlated to DHEA:cortisol (r=.758, p<.05).The findings indicate that plasma IsoFs and F 2 -IsoPs are elevated in older subjects with CFS and that isoprostane and isofuran ratios are associated with HPA dysregulation.