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Background: White matter hyperintensity (WMH) is a marker of age‐related cerebrovascular damage and is correlated with cognitive impairment; ischemia and inflammatory mechanisms have been proposed to be involved in its pathogenesis. These processes are associated with oxidative stress (OS), which may impair cellular function and affect antioxidant balance; however, the role of central antioxidant responses is still unclear. Method: Patients (age 55‐85) with ≥2 vascular risk factors or a previous vascular event were assessed at baseline for an exercise rehabilitation program. All participants completed the Montreal Cognitive Assessment (MoCA). Baseline WHM severity was determined using the standardized Canadian Dementia Imaging Protocol and semiautomatic protocols. Brain glutathione (GSH) at baseline was obtained in the anterior cingulate (AC) and occipital region (OC) using 1H magnetic resonance spectroscopy (MEscher–GArwood Point Resolved Spectroscopy). Spectroscopic analysis was completed using the Gannet toolkit (vers. 3.1) in Matlab (vers. 2020b). Result: Of 30 participants (mean age: 66.2 ± 7.42 SD; 80% male) currently enrolled, brain volumetric measurements were completed for 25 participants. Lower MoCA score was associated with greater total WMH volume, controlling for age (b[SE] = ‐0.017 [0.005], t(22) = ‐3.24, p = 0.004); this relationship remained significant when controlling for years of education separately (b[SE] = ‐0.016 [0.006], t(22) = ‐2.86, p = 0.01). Correcting for cerebrospinal fluid volume, lower AC‐GSH level was associated with higher deep WMH volume in the medial middle frontal (MMF) region of interest (b[SE] = ‐0.056 [0.023], t(23) = ‐2.38, p = 0.026), but not with MMF paraventricular WMH volume. After controlling for age, the model was no longer significant (F (2, 22) = 2.87, p = 0.078). No significant associations were found between OC‐GSH and occipital lobe WMH. Conclusion: As expected, total white matter hyperintensity volume was associated with poorer global cognition. In the medial middle frontal (MMF) region of interest, higher deep WMH was associated with lower GSH levels, suggesting altered brain antioxidant levels may be associated with the presence or formation of WMH. Recruitment is ongoing, and additional participants are needed to reinforce findings and to control for confounders in the analysis. [ABSTRACT FROM AUTHOR]

Background: Oxidative stress (OS) has been implicated in age‐related neurodegeneration and may be important in prodromal states such as mild vascular cognitive impairment (mVCI). Higher peripheral OS is reported in mVCI patients; however, the role of central antioxidant defenses in mVCI is unclear. Glutathione (GSH) is a major brain antioxidant, and so brain GSH in possible mVCI vs. controls was assessed. Method: Possible mVCI patients (1 standard deviation (SD) below population norms in verbal memory, executive function (EF), processing speed, or working memory, age 55‐85, and currently enrolled in a cardiac rehabilitation program due to having 2 or more vascular risk factors or previous vascular event) and cognitively‐normal (CN) controls are recruited from a 6‐month exercise rehabilitation program. All participants received 1H magnetic resonance spectroscopy (MEscher–GArwood Point Resolved Spectroscopy) to quantify brain GSH at baseline in the anterior cingulate (AC) and occipital region (OC). Spectroscopic analysis was completed using the Gannet toolkit (vers. 3.1) in Matlab (vers. 2020b), a cut‐off of 20% was used to reject spectra of poor quality. Result: In 30 participants (mVCI n = 16, CN n = 14), anterior cingulate (AC) GSH (I.U. ± SD) was higher in mVCI (1.86 ± 0.45) compared to CN (1.63 ± 0.50) (F(1,18.8) = 4.6, P = 0.04), this difference became trending after correcting for cerebrospinal fluid volume ((F(1,18.2) = 3.9, P = 0.06). No difference was detected for OC‐GSH before or after correcting for cerebrospinal fluid volume. Higher AC‐GSH was correlated with lower Montreal Cognitive Assessment score (rho (26) = ‐0.42, p = 0.02). Conclusion: Preliminary data suggest an upregulation in anterior cingulate glutathione in mVCI, which might reflect a compensatory increase in antioxidants as a response to increase peripheral oxidative stress previously reported in these patients. Recruitment is ongoing and additional participants are needed to reinforce findings. [ABSTRACT FROM AUTHOR]

Oxidative stress (OS) has been implicated in age-related neurodegeneration and may be important in prodromal states such as mild vascular cognitive impairment (mVCI). Higher peripheral OS is reported in mVCI patients; however, the role of central antioxidant defenses in mVCI is unclear. Glutathione (GSH) is a major brain antioxidant, and so brain GSH in possible mVCI vs. controls was assessed. Possible mVCI patients (1 standard deviation (SD) below population norms in verbal memory, executive function (EF), processing speed, or working memory, age 55-85, and currently enrolled in a cardiac rehabilitation program due to having 2 or more vascular risk factors or previous vascular event) and cognitively normal (CN) controls are recruited from a 6-month exercise rehabilitation program. All participants received 1H magnetic resonance spectroscopy (MEscher–GArwood Point Resolved Spectroscopy) to quantify brain GSH at baseline in the anterior cingulate (AC) and occipital cortex (OC). Spectroscopic analysis was completed using the Gannet toolkit (vers. 3.1) in Matlab (vers. 2020b). In 28 participants (mVCI n = 14, CN n = 14), after correcting for cerebrospinal fluid volume, anterior cingulate (AC) GSH (I.U. ± SD) was higher in mVCI (2.67 ± 0.29) compared to CN (2.25 ± 0.67) (F (1,25) = 4.7, P = 0.04) but not in the occipital cortex (OC, F (1, 25) = 1.3, p = 0.27). Higher AC-GSH was correlated with lower Montreal Cognitive Assessment score (rho (24) = -0.46 p = 0.02). In mVCI participants, higher AC-GSH also correlated with lower EF composite score (r (12) = -0.55 p = 0.04). Preliminary data suggest an upregulation in anterior cingulate glutathione in mVCI, which might reflect a compensatory increase in antioxidants as a response to increase peripheral oxidative stress previously reported in these patients. Recruitment is ongoing and additional participants are needed to reinforce findings. Canadian Institute of Health Research (#376204), the Alzheimer's Association Part the Cloud™ (PTC-18-543823), and the Alzheimer Society of Canada Research Program (21-11) [ABSTRACT FROM AUTHOR]

Background: Increasing evidence implicates oxidative stress (OS) in Alzheimer Disease (AD) and Mild Cognitive Impairment (MCI). Depletion of the brain antioxidant glutathione (GSH) may be important in OS‐mediated neurodegeneration, though post‐mortem brain GSH changes in AD have been inconclusive. Recent in vivo measurements of brain and peripheral GSH may shed light on GSH changes, with implications for its role as a biomarker and therapeutic target. Aim: To quantitatively review in vivo GSH in AD and MCI compared to healthy controls (HC) using meta‐analysis. Method: Studies published before June 2020 containing measurements of in vivo brain or peripheral GSH in MCI or AD with a HC group were identified using Medline, PsychInfo, and Embase. Standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated for outcomes using random effects models. Outcome measures included brain GSH (Meshcher‐Garwood Point Resolved Spectroscopy (MEGA‐PRESS versus non) in AD and MCI, and peripheral GSH (intracellular versus extracellular) in AD and MCI. The Q statistic and Egger's test were used to assess heterogeneity and risk of publication bias respectively. Results: For brain GSH, 4 AD (AD=175, HC=272) and 4 MCI (MCI=254, HC=260) studies were included. For peripheral GSH, 26 AD (ADD=981, HCl=993) and 7 MCI (MCI=434, HC=408) studies were included. Brain GSH did not differ in AD or MC compared to HC; however, the subgroup of studies using MEGA‐PRESS reported lower brain GSH in AD (SMD [95%CI] = ‐1.47 [‐1.91, ‐1.02], p=0.02) and MCI (‐1.08 [‐1.53,‐0.64], p=0.01). Peripheral GSH was lower in AD (‐0.94 [‐1.37, ‐0.51], p<0.001). In a subgroup analysis, intracellular GSH was lower in MCI (‐0.66 [‐1.11, ‐0.21], p=0.02). Significant heterogeneity was observed in all analyses and supported the use of random effect models. Egger's test indicated risk of publication bias in MCI brain GSH literature. Conclusion: In vivo measures of GSH in AD and MCI had significant heterogeneity. Peripheral analyses suggested intracellular GSH decreases may be prominent in early disease stages with both intra‐ and extracellular decreases in later stages. Brain GSH may be decreased in AD and MCI but heterogeneity and potential bias indicate the need for measurement standardization and replication. [ABSTRACT FROM AUTHOR]