Nursing & Health

Permanent URI for this collectionhttps://research.avondale.edu.au/handle/123456789/457

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    A Pilot Study Providing Evidence for a Relationship between a Composite Lifestyle Score and Risk of Higher Carotid Intima-Media Thickness: Is There a Link to Oxidative Stress?
    (2018-04-26) Grant, Ross; Bilgin, Ayse; Berg, Jade; Seyedsadjadi, Neda

    Lifestyle behaviours have been closely linked to the progressive cell damage associated with oxidative stress (OS) and the development of cardiovascular disease (CVD). Early detection of lifestyle-linked OS may therefore be useful in the early identification of prodromal disease. To test this hypothesis, this study assessed the relationship between a comprehensive redox balance lifestyle score (RBLS) and carotid intima-media thickness (CIMT), a recognized marker for CVD, and plasma biomarkers of OS. In a cross-sectional study design, 100 apparently healthy middle-aged participants were asked to complete a comprehensive lifestyle questionnaire, followed by DXA scanning, CIMT ultrasonography, and blood collection. The RBLS was composed of lifestyle components with pro- and antioxidant properties with a higher score indicative of lower oxidative activity. Multiple linear regression and logistic regression analysis were performed for statistical analysis. The RBLS was significantly associated with the risk for increased CIMT that was independent of conventional CVD risk factors (χ2 9 = 35 60, P ≤ 0 001). The adjusted model explained 42.4% of the variance in CIMT. Participants with RBLS below the median were at significantly increased risk of higher CIMT compared to participants with RBLS above the median (OR = 3 60, 95% CI: 1.19–10.88, P = 0 023). Significant associations were also observed between the RBLS, plasma total antioxidant capacity (TAC) (r 99 = 0 28, P = 0 006), hydroperoxide (HPX) (rs 99 = −0 28, P = 0 005), TAC/HPX ratio (r 98 = 0 41, P ≤ 0 001), γ-glutamyltransferase (r 97 = −0 23, P = 0 024), uric acid (r 98 = −0 20, P = 0 045), and inflammatory C-reactive protein (rs 97 = −0 25, P = 0 012) and interleukin-1β (r 97 = −0 21, P = 0 040). These findings highlight the importance of identifying the collective influence of lifestyle behaviours on OS activity and its potential to remodel the vascular endothelium.

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    Cerebrospinal Fluid Levels of Inflammation, Oxidative Stress and NAD+ are Linked to Differences in Plasma Carotenoid Concentrations
    (2014-07-01) Bilgin, Ayse; Croft, Kevin D.; Mori, Trevor A.; Garg, Manohar; Grant, Ross; Guest, Jade

    Background: The consumption of foods rich in carotenoids that possess significant antioxidant and inflammatory modulating properties has been linked to reduced risk of neuropathology. The objective of this study was to evaluate the relationship between plasma carotenoid concentrations and plasma and cerebrospinal fluid (CSF) markers of inflammation, oxidative stress and nicotinamide adenine dinucleotide (NAD+) in an essentially healthy human cohort.

    Methods: Thirty-eight matched CSF and plasma samples were collected from consenting participants who required a spinal tap for the administration of anaesthetic. Plasma concentrations of carotenoids and both plasma and cerebrospinal fluid (CSF) levels of NAD(H) and markers of inflammation (IL-6, TNF-α) and oxidative stress (F2-isoprostanes, 8-OHdG and total antioxidant capacity) were quantified.

    Results: The average age of participants was 53 years (SD = 20, interquartile range = 38). Both α-carotene (P = 0.01) and β-carotene (P < 0.001) correlated positively with plasma total antioxidant capacity. A positive correlation was observed between α-carotene and CSF TNF-α levels (P = 0.02). β-cryptoxanthin (P = 0.04) and lycopene (P = 0.02) inversely correlated with CSF and plasma IL-6 respectively. A positive correlation was also observed between lycopene and both plasma

    (P < 0.001) and CSF (P < 0.01) [NAD(H)]. Surprisingly no statistically significant associations were found between the most abundant carotenoids, lutein and zeaxanthin and either plasma or CSF markers of oxidative stress.

    Conclusion: Together these findings suggest that consumption of carotenoids may modulate inflammation and enhance antioxidant defences within both the central nervous system (CNS) and systemic circulation. Increased levels of lycopene also appear to moderate decline in the essential pyridine nucleotide [NAD(H)] in both the plasma and the CSF.

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    Changes in Oxidative Damage, Inflammation and [NAD(H)] with Age in Cerebrospinal Fluid
    (2014-01-14) Croft, Kevin D.; Mori, Trevor A.; Grant, Ross; Guest, Jade

    An extensive body of evidence indicates that oxidative stress and inflammation play a central role in the degenerative changes of systemic tissues in aging. However a comparatively limited amount of data is available to verify whether these processes also contribute to normal aging within the brain. High levels of oxidative damage results in key cellular changes including a reduction in available nicotinamide adenine dinucleotide (NAD+), an essential molecule required for a number of vital cellular processes including DNA repair, immune signaling and epigenetic processing.

    In this study we quantified changes in [NAD(H)] and markers of inflammation and oxidative damage (F2-isoprostanes, 8-OHdG, total antioxidant capacity) in the cerebrospinal fluid (CSF) of healthy humans across a wide age range (24–91 years). CSF was collected from consenting patients who required a spinal tap for the administration of anesthetic. CSF of participants aged .45 years was found to contain increased levels of lipid peroxidation (F2-isoprostanes) (p = 0.04) and inflammation (IL-6) (p = 0.00) and decreased levels of both total antioxidant capacity (p = 0.00) and NAD(H) (p = 0.05), compared to their younger counterparts.

    A positive association was also observed between plasma [NAD(H)] and CSF NAD(H) levels (p = 0.03). Furtheranalysis of the data identified a relationship between alcohol intake and CSF [NAD(H)] and markers of inflammation. The CSF of participants who consumed .1 standard drink of alcohol per day contained lower levels of NAD(H) compared to those who consumed no alcohol (p,0.05). An increase in CSF IL-6 was observed in participants who reported drinking .0–1 (p,0.05) and .1 (p,0.05) standard alcoholic drinks per day compared to those who did not drink alcohol. Taken together these data suggest a progressive age associated increase in oxidative damage, inflammation and reduced [NAD(H)] in the brain which may be exacerbated by alcohol intake.

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    The Effect of Antioxidant Supplementation on Fatigue During Exercise: Potential Role for NAD+(H)
    (2010-03-01) Bentley, David J.; Grant, Ross; Dank, Steve; Midgley, Adrian W.; Mach, John

    This study compared serum pyridine levels (NAD+ /NADH) in trained (n = 6)and untrained (n = 7) subjects after continuous progressive exercise at 50%, 70% then 95% of physical work capacity until fatigue (TTF) after consuming a placebo or antioxidant (AO) cocktail (Lactaway ©). An increase of 17% in TTF was observed in AO as compared to placebo (p = 0.032). This was accompanied by a significant increase in serum NAD+ levels (p = 0.037) in the AO supplemented group post exercise. The increases in NAD+ and improved endurance reflect lower oxidative stress-induced suppression of aerobic respiration.