ORCID Profile
0000-0002-6550-5646
Current Organisation
University of Tasmania
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Publisher: MDPI AG
Date: 09-03-2016
DOI: 10.3390/NU8030150
Publisher: Elsevier BV
Date: 12-2018
DOI: 10.1016/J.ARR.2018.10.005
Abstract: Menopause is a critical period during which, without timely interventions, increased risks of cardiovascular and metabolic diseases, osteoporosis, sexual dysfunction and premature cognitive decline will contribute to diminished quality-of-life in women. Hormone therapy (HT) used to be the standard of care for managing vasomotor symptoms and prevention of chronic diseases until publication of the Women's Health Initiative (WHI) in 2002. Concerned about risks highlighted in WHI publications, many symptomatic women promptly ceased HT which resulted in increased vasomotor symptoms, osteoporosis-related-fractures and insomnia. Data from post-hoc WHI analyses and newer clinical trials consistently show reductions in coronary heart disease and mortality when estrogen therapy is initiated soon after menopause, whereas administration in later years and/or in combination with progesterone carries increased risks. However, no validated primary preventive strategies are available for younger postmenopausal women ( 60 years), risks associated with oral HT exceed benefits however transdermal estrogen may offer a safer alternative and should be further evaluated. Alternative therapies such as phytoestrogens and non-hormonal prescriptions may be beneficial for older women or those who are unsuitable for HT. Long-term head-to-head comparisons of HT with alternative interventions are warranted to confirm their efficacy for chronic disease prevention.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 31-08-2020
DOI: 10.1097/GME.0000000000001643
Abstract: Following concerns about hormone therapy, postmenopausal women need alternative options to manage menopause-related symptoms and improve their well-being. A 14-week pilot study has shown that supplementation with resveratrol, a phytoestrogen with circulatory benefits, can improve aspects of well-being including chronic pain, which is a common complaint in postmenopausal women. We aimed to confirm these benefits in a larger, long-term study. The Resveratrol for Healthy Ageing in Women study, a 24-month randomized, double-blind, placebo-controlled, two-period crossover intervention trial of resveratrol supplementation (75 mg BID) was conducted in 125 healthy postmenopausal women to evaluate effects on cognitive performance (results published elsewhere). Aspects of well-being including pain perception, mood and depressive symptoms, menopausal symptoms, sleep quality, and quality of life were assessed with questionnaires as secondary outcomes of the study. Cerebrovascular responsiveness to hypercapnia was measured as a surrogate marker of cerebrovascular function. Resveratrol supplementation reduced composite pain score ( P 0.001), especially in overweight in iduals this was associated with improvements in cerebrovascular responsiveness to hypercapnia (R = −0.329, P = 0.014). Somatic menopausal symptoms ( P = 0.024) and general well-being ( P = 0.010) were also improved after resveratrol supplementation. These results confirm the pilot study finding that resveratrol supplementation can reduce chronic pain in age-related osteoarthritis and improve menopause-related quality of life in postmenopausal women. These improvements are sustained by supplementation for at least 12 months and are associated with enhancement of circulatory function. ACTRN12616000679482p Video Summary: links.lww.com/MENO/A638.
Publisher: Elsevier BV
Date: 03-2018
Publisher: MDPI AG
Date: 22-02-2023
Abstract: The rising prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacterales is a significant threat to animal and human health. This study aims to describe the clinical features, antimicrobial susceptibility patterns, and genotypic features of infections associated with ESBL-producing Enterobacterales in dogs and cats seen at a tertiary referral veterinary teaching hospital. Enterobacterales isolated from dogs and cats that underwent ESBL testing during the study period were identified using a search of the hospital antimicrobial susceptibility test software database. Medical records of confirmed ESBL isolates were reviewed, and the source of infection, clinical findings, and antimicrobial susceptibility were recorded. Genomic DNA from bacterial isolates was evaluated for antimicrobial resistance genes with whole genome sequencing. Thirty ESBL-producing isolates were identified based on phenotypic testing (twenty-nine from dogs, one from a cat) twenty-six were Escherichia coli and the remainder were Klebsiella spp. Bacterial cystitis was the most commonly identified (8/30, 27%) clinical problem associated with infection. Resistance to three or more antimicrobial classes was identified in 90% (27/30) of isolates, and all isolates were susceptible to imipenem. Over 70% of isolates were susceptible to piperacillin-tazobactam, amikacin, and cefoxitin. BlaCTX-M-15 was the most common ESBL gene identified, present in 13/22 (59%) isolate genomes. A wide range of clinical infections were identified. Piperacillin-tazobactam and amikacin may be alternatives to carbapenem therapy. Further, larger-scale studies are needed.
Publisher: MDPI AG
Date: 02-10-2018
DOI: 10.3390/NU10101413
Abstract: Purported benefits of long chain omega-3 polyunsaturated fatty acid (LCn-3PUFA) for brain function may be attributable, at least in part, to improved cerebral perfusion. A pilot randomised controlled trial was undertaken to investigate effects of taking a DHA-rich fish oil supplement for 20 weeks on cerebrovascular function, mood and cognitive performance. Borderline hypertensives aged 40–85 years with low habitual LCn-3PUFA intake took four capsules/day of EPAX (1600 mg DHA + 400 mg EPA) or placebo (corn oil). Cerebrovascular function was assessed at baseline and after 20 weeks in 38 completers (19 on each supplement) using transcranial Doppler ultrasound of blood flow in the middle cerebral artery at rest and whilst performing a battery of cognitive tasks (neurovascular coupling). The primary outcome, cerebrovascular responsiveness (CVR) to hypercapnia, increased 26% (p = 0.024) in women there was no change in men. In contrast, neurovascular coupling increased significantly (p = 0.01 for the overall response) in men only the latter correlated with an increase of EPA in erythrocytes (r = 0.616, p = 0.002). There was no associated improvement of mood or cognition in either men or women. These preliminary observations indicate that LCn-3PUFA supplementation has the potential to enhance blood flow in the brain in response to both hypercapnic and cognitive stimuli. Future studies should examine differential effects of EPA and DHA and take account of the gender differences in responsiveness to supplementation.
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.PHRS.2019.01.009
Abstract: Type-2 diabetes (T2D) increases the risk of dementia by ˜5-fold, however the mechanisms by which T2D increases dementia risk remain unclear. Evidence suggests that the heightened inflammation and oxidative stress in T2D may lead to disruption of the blood-brain barrier (BBB), which precedes premature cognitive decline. Studies show that vascular-targeted anti-inflammatory treatments protect the BBB by attenuating neuroinflammation, and in some studies attenuate cognitive decline. Yet, this potential pathway is understudied in T2D-associated cognitive impairment. In recent years, therapeutic potential of cannabinoids has gained much interest. The two major cannabinoids, cannabidiol and tetrahydrocannabinol, exert anti-inflammatory and vascular protective effects, however few studies report their potential for reversing BBB dysfunction, particularly in T2D. Therefore, in this review, we summarize the current findings on the role of BBB dysfunction in T2D-associated dementia and consider the potential therapeutic use of cannabinoids as a protectant of cerebrovascular BBB protection.
Publisher: MDPI AG
Date: 23-09-2020
DOI: 10.3390/NU12102902
Abstract: Curcumin has previously been shown to enhance mood in non-depressed older adults. However, observed benefits were limited to short-term supplementation (4 weeks). In a 16 week randomized, double-blind, placebo-controlled, 2 × 2 factorial design trial, we supplemented overweight or obese non-depressed adults (50–80 years) with curcumin (160 mg/day), fish oil (2000 mg docosahexaenoic acid +400 mg eicosapentaenoic acid/day), or a combination of both. Secondary outcomes included mental wellbeing measures (mood states and subjective memory complaints (SMCs)) and quality of life (QoL). Furthermore, plasma apolipoprotein E4 (APOE4) was measured to determine whether APOE4 status influences responses to fish oil. Curcumin improved vigour (p = 0.044) compared to placebo and reduced SMCs compared to no curcumin treatment (p = 0.038). Fish oil did not affect any mood states, SMCs or QoL however, responses to fish oil were affected by APOE4 status. In APOE4 non-carriers, fish oil increased vigour (p = 0.030) and reduced total mood disturbances (p = 0.048) compared to placebo. Improvements in mental wellbeing were correlated with increased QoL. Combining curcumin with fish oil did not result in additive effects. This exploratory analysis indicates that regular supplementation with either curcumin or fish oil (limited to APOE4 non-carriers) has the potential to improve some aspects of mental wellbeing in association with better QoL.
Publisher: Elsevier BV
Date: 04-2020
Publisher: MDPI AG
Date: 24-08-2018
DOI: 10.3390/NU10091160
Abstract: Pre-clinical data and human trials indicate that resveratrol supplementation may help to counteract diabetes. Several mechanisms of action have been proposed to explain its metabolic benefits, including activation of sirtuins and estrogen receptors (ER) to promote glucose transporter type-4 (GLUT4) translocation and increase glucose uptake. Resveratrol can also enhance vasodilator function, yet the possibility that this action might help to alleviate insulin resistance in type-2 diabetes mellitus has received little attention. In this brief review we propose that, by restoring impaired endothelium-dependent vasodilatation in insulin resistant in iduals resveratrol increases blood perfusion of skeletal muscle, thereby facilitating glucose delivery and utilization with resultant improvement of insulin sensitivity. Thus, circulatory improvements by vasoactive nutrients such as resveratrol may play a role in preventing or alleviating insulin resistance.
Publisher: MDPI AG
Date: 12-07-2016
DOI: 10.3390/NU8070425
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.PHYSBEH.2018.04.007
Abstract: Our aim was to assess cerebral blood flow changes during cybersickness. Transcranial Doppler (TCD) ultrasound and near infrared spectroscopy (NIRS) were used separately in two independent experiments. In both studies, a 15-min virtual roller coaster ride was used as a provocative visual stimulus. Subjective nausea ratings were obtained at 1 min intervals. The TCD study was performed in 14 healthy subjects (8 males and 6 females) in this study we also measured heart rate and arterial pressure. In a separate study a 52-channel NIRS device (Hitachi ETG-4000) was used to monitor activated brain regions by measuring oxy-hemoglobin (HbO
Publisher: SAGE Publications
Date: 20-09-2020
Abstract: Derangements in cerebrovascular structure and function can impair cognitive performance throughout ageing and in cardiometabolic disease states, thus increasing dementia risk. Modifiable lifestyle factors that cause a decline in cardiometabolic health, such as physical inactivity, exacerbate these changes beyond those that are associated with normal ageing. The purpose of this review was to examine cerebrovascular, cognitive and neuroanatomical adaptations to ageing and the potential benefits of exercise training on these outcomes in adults 50 years or older. We systematically searched for cross-sectional or intervention studies that included exercise (aerobic, resistance or multimodal) and its effect on cerebrovascular function, cognition and neuroanatomical adaptations in this age demographic. The included studies were tabulated and described narratively. Aerobic exercise training was the predominant focus of the studies identified there were limited studies exploring the effects of resistance exercise training and multimodal training on cerebrovascular function and cognition. Collectively, the evidence indicated that exercise can improve cerebrovascular function, cognition and neuroplasticity through areas of the brain associated with executive function and memory in adults 50 years or older, irrespective of their health status. However, more research is required to ascertain the mechanisms of action.
Publisher: Elsevier BV
Date: 02-2018
Publisher: MDPI AG
Date: 20-03-2020
DOI: 10.3390/NU12030828
Abstract: Deficits in the cerebral microcirculation contribute to age-related cognitive decline. In a pilot study of postmenopausal women, we found that supplementation with a low dose of resveratrol, a phytoestrogen, for 14 weeks improved cerebrovascular and cognitive functions. We have since undertaken a larger, longer term study to confirm these benefits. Postmenopausal women aged 45–85 years (n = 129) were randomized to take placebo or 75 mg trans-resveratrol twice daily for 12 months. Effects on cognition, cerebral blood flow, cerebrovascular responsiveness (CVR) and cardiometabolic markers (blood pressure, diabetes markers and fasting lipids) were assessed. Compared to placebo, resveratrol improved overall cognitive performance (P 0.001) and attenuated the decline in CVR to cognitive stimuli (P = 0.038). The latter effect was associated with reduction of fasting blood glucose (r = −0.339, P = 0.023). This long-term study confirms that regular consumption of resveratrol can enhance cognitive and cerebrovascular functions in postmenopausal women, with the potential to slow cognitive decline due to ageing and menopause.
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.NUMECD.2016.03.003
Abstract: Progressive microvascular dysfunction in type 2 diabetes mellitus (T2DM) may impair the ability of cerebral vessels to supply blood to brain regions during local metabolic demand, thereby increasing risks of dementia. Having previously demonstrated that resveratrol can enhance vasodilator function in the systemic circulation, we hypothesised that resveratrol could similarly benefit the cerebral circulation. We aimed to determine the most efficacious dose of resveratrol to improve cerebral vasodilator responsiveness (CVR) in T2DM. In a double-blind, placebo-controlled, balanced crossover intervention, 36 dementia-free, non-insulin dependent T2DM older adults (49-78 years old) consumed single doses of synthetic trans-resveratrol (0, 75, 150, and 300 mg) at weekly intervals. Transcranial Doppler ultrasound was used to assess CVR to a hypercapnic stimulus, both before and 45 min after treatment. CVR, measured bilaterally in the middle cerebral arteries (MCA) and posterior cerebral arteries (PCA), was expressed as the percentage change in mean blood flow velocity from baseline to the peak velocity attained during hypercapnia. Resveratrol consumption increased CVR in the MCA mean within-in idual changes for each dose from placebo were 13.8 ± 3.5% for 75 mg (P = 0.001), 8.9 ± 3.5% for 150 mg (P = 0.016), and 13.7 ± 3.3% for 300 mg (P < 0.001) only the 75 mg dose was efficacious in the PCA (13.2 ± 4.5%, P = 0.016). Our results provide the first clinical evidence of an acute enhancement of vasodilator responsiveness in cerebral vessels following consumption of resveratrol in this population who are known to have endothelial dysfunction and sub-clinical cognitive impairment. Importantly, maximum improvement was observed with the lowest dose used. ACTRN12614000891628 (www.anzctr.org.au).
Publisher: Oxford University Press (OUP)
Date: 2020
DOI: 10.1093/RAP/RKAA036
Abstract: OA is a leading cause of chronic pain and disability. Next to inflammation, vascular pathology has been hypothesized to play a role in its aetiology and progression. Owing to side effects and the low efficacy of pharmacological treatments, dietary supplements are popular as alternative treatments, but evidence of efficacy is limited. We tested whether fish oil and curcumin supplementation can reduce chronic pain and OA burden in older adults. A 16-week randomized, double-blind, placebo-controlled, 2 × 2 factorial design supplementation trial with fish oil (2000 mg/day docosahexaenoic acid + 400 mg/day eicosapentaenoic acid), curcumin (160 mg/day) or a combination of both was undertaken in sedentary overweight/obese older adults. Secondary outcomes included treatment-induced changes in self-reported chronic pain and OA burden and whether changes were related to changes in small artery elasticity (surrogate marker for microvascular function), CRP (inflammatory marker) and well-being. The majority of participants (131 of 152) reported chronic pain, which was predominantly OA specific. Fish oil significantly reduced OA-specific pain (P = 0.002, Cohen’s d = 0.56) and burden (P = 0.015, Cohen’s d = 0.45) compared with no fish oil treatment reductions were correlated with improvements in microvascular function and well-being. Curcumin, alone or in combination with fish oil, did not reduce pain measures. Our findings indicate potential for fish oil to alleviate OA pain and burden in overweight/obese older adults. Further investigations should be undertaken in patients with clinically diagnosed OA to evaluate fish oil alone and as an adjunct to conventional pharmacotherapy and to investigate underlying mechanisms. Australian and New Zealand Clinical Trials Register, www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=370788, ACTRN12616000732482p.
Publisher: MDPI AG
Date: 05-11-2014
DOI: 10.3390/NU6114881
Publisher: Springer Science and Business Media LLC
Date: 02-10-2014
DOI: 10.1007/S11892-014-0547-4
Abstract: Associations between type 2 diabetes mellitus (T2DM) and accelerated cognitive decline are well established. However, the sensitivity of neuropsychological tests to detect early deficits in cognitively normal adults with T2DM is unknown. This review examined cognitive domains and specific neuropsychological tests that are impaired in T2DM, based on clinically significant differences (effect sizes >0.5) between T2DM and groups without T2DM. Nine cross-sectional studies were identified which reported means and standard deviations for in idual tests. Tests of executive function, working memory and psychomotor and attentional functions were found to be impaired in T2DM. Impairments of executive function and choice reaction time may have consequences for everyday functioning, in particular the risk of falls in older adults. More research on cognitive deficits in dual-task situations and how they impact everyday functioning is needed the Trail Making Task, Symbol Digit Modalities Test, Verbal Fluency Task and tests of reaction time and processing speed could be included as core components of test batteries in future intervention studies. They could also be assessed in newly diagnosed T2DM and used to monitor progressive deterioration of cognitive function and the efficacy of therapeutic interventions on cognitive function.
Publisher: SAGE Publications
Date: 22-10-2020
Abstract: Previous studies have investigated whether migraine is a circulatory disorder, as migraineurs are at heightened risk of cerebrovascular disease. However, in most cases, systemic vascular function was evaluated, which may not reflect abnormalities in the cerebral circulation. Therefore, we aimed to determine whether cerebrovascular function differs between migraineurs and controls. A systematic literature search was conducted across three electronic databases to search for studies that compared cerebrovascular function in migraineurs to controls. Where applicable, meta-analyses were used to determine standardised mean differences (SMD) between migraineurs and controls. Seventy articles were identified, 40 of which contained quantitative data. Meta-analyses showed pulsatility index (PI) was higher (SMD = 0.23 95%CI = 0.05 to 0.42, P = 0.01) and cerebrovascular responsiveness (CVR) to hypercapnia was lower (SMD=−0.34 95%CI=−0.67 to −0.01, P = 0.04) in the posterior circulation of migraineurs, particularly those without aura. The meta-analyses also indicated that migraineurs have higher resting mean blood flow velocity in both anterior (SMD = 0.14 95%CI = 0.05 to 0.23, P = 0.003) and posterior circulations (SMD = 0.20 95%CI = 0.05 to 0.34, P = 0.007). Compared to healthy controls, migraineurs have altered cerebrovascular function, evidenced by elevated PI (representing arterial stiffness) and impaired CVR to hypercapnia (representing cerebral vasodilator function). Future studies should investigate whether improvement of cerebrovascular function is able to alleviate migraine.
Publisher: Frontiers Media SA
Date: 07-07-2021
DOI: 10.3389/FNEUR.2021.694980
Abstract: Background: Migraineurs, particularly young premenopausal women, are at increased risk of cerebrovascular disease however, there is currently limited evidence as to whether hormonal migraine is associated with poor cerebrovascular function. Objectives: The objectives of this study were to: (1) investigate the potential association of cerebrovascular function with hormonal migraine and (2) determine whether abnormalities of cerebrovascular function in hormonal migraineurs are associated with migraine-related disability and/or quality of life. Method: A cross-sectional study was undertaken in 50 hormonal migraineurs (mean age: 38.7 ± 1.2 years) and 29 controls (mean age: 35.6 ± 1.8 years). Data were collected at a single point in time from all participants during the inter-ictal period when they were free from migraine and not menstruating. Transcranial Doppler ultrasound was used to measure resting blood flow velocity and cerebrovascular responsiveness (CVR) to hypercapnia and cognitive stimulation (neurovascular coupling) in the left and right middle cerebral artery (MCA). Additionally, hormonal migraineurs completed three questionnaires to assess migraine-related disability and quality of life as well as migraine frequency and intensity: Headache Impact Test-6™, Migraine-Specific Quality of Life and Migraine Disability Assessment. Results: Hormonal migraineurs had lower resting mean blood flow velocity (MBFV) ( P = 0.009) and neurovascular coupling during cognitive stimulation ( P = 0.010) in the left MCA than controls. No such differences were found in the right MCA. Additionally, heart rate ( P = 0.004) was higher in hormonal migraineurs than controls. However, no differences in CVR to hypercapnia were found between hormonal migraineurs and controls. Multi-variate analysis revealed age to be a significant ( P = 0.012) predictor of MBFV in the left MCA. Negative correlations between headache frequency and CVR to hypercapnia in the left ( P = 0.026) and right MCA ( P = 0.044) were found. Additionally, negative correlations between neurovascular coupling during the 2-Back 1.5 s task in the right MCA and the MSQoL emotional ( P = 0.013) and role-function restrictive ( P = 0.039) domains were found. Conclusions: This is the first study to show that hormonal migraineurs have poorer cerebrovascular function, as represented by lower resting MBFV and impaired neurovascular coupling in the left MCA. Future studies should investigate whether improving cerebrovascular function can prevent hormonal migraine and improve quality of life. Clinical Trial Registration: ACTRN12618001230246.
Publisher: Elsevier BV
Date: 2019
Publisher: MDPI AG
Date: 10-05-2019
DOI: 10.3390/NU11051043
Abstract: The authors wish to make a correction to the published version of their paper [...]
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2017
DOI: 10.1097/GME.0000000000000861
Abstract: Pain is a common complaint among postmenopausal women. It has been postulated that vascular dysfunction caused by estrogen decline at menopause plays a key role in the initiation and progression of degradative joint disease, namely age-related osteoarthritis. We evaluated whether supplementation with resveratrol, a phytoestrogen, could improve aspects of well-being such as chronic pain that is commonly experienced by postmenopausal women. A 14-week randomized, double-blind, placebo-controlled intervention with trans-resveratrol (75 mg, twice daily) was conducted in 80 healthy postmenopausal women. Aspects of well-being, including pain, menopausal symptoms, sleep quality, depressive symptoms, mood states, and quality of life were assessed by Short form-36 at baseline and at the end of treatment. Rating scales were averaged to provide a composite score representing overall well-being. Cerebral vasodilator responsiveness to hypercapnia was also assessed as a surrogate marker for cerebrovascular function. Compared with placebo treatment, there was a significant reduction in pain and an improvement in total well-being after resveratrol supplementation. Both benefits, including measures of quality of life, correlated with improvements in cerebrovascular function. Our preliminary findings indicate potential for resveratrol treatment to reduce chronic pain in age-related osteoarthritis. Resveratrol consumption may also boost perceptions of well-being in postmenopausal women. Further investigation to elucidate underlying mechanisms is warranted.
Publisher: Wiley
Date: 09-2017
DOI: 10.1111/NYAS.13459
Abstract: Recent evidence indicates that resveratrol, a phytoestrogen, can improve cognitive function in postmenopausal women by enhancing cerebral vasodilator responsiveness. We examine the effects of phytoestrogen supplementation on cognition and compare resveratrol with other phytoestrogens. Databases were searched for reports of randomized controlled trials (RCTs) containing terms describing phytoestrogens together with terms relating to cognition. Effect sizes were determined for changes in cognition. We identified 23 RCTs, 15 with isoflavone and eight with resveratrol or grape formulations. Six soy isoflavone studies showed positive cognitive effects of medium size. Greater benefits were seen in women who were <10 years postmenopausal and supplemented for <6 months. Small-to-medium effect-size cognitive benefits of resveratrol were seen in four studies of older adults of mixed gender and in postmenopausal women who took 150-200 mg resveratrol daily for at least 14 weeks. No benefits were seen in three studies using red clover or grape formulations. Supplementation with either soy isoflavone or resveratrol improved executive function and memory domains of cognitively normal older adults in half of the included studies, mostly with medium effect sizes. The cognitive benefit of resveratrol was related to improved cerebral perfusion.
Publisher: Wiley
Date: 14-06-2018
DOI: 10.1111/RESP.13343
Publisher: Wiley
Date: 03-08-2016
Publisher: Computers, Materials and Continua (Tech Science Press)
Date: 25-03-2019
DOI: 10.1111/CHD.12763
Abstract: Improvements in the management of complex congenital heart disease, including those with single ventricle physiology, have resulted in increased survival. As this population ages, the recognition of cognitive impairment is increasingly important. At present, little is known about the potential mechanisms of cognitive dysfunction. In this cross-sectional study, we aimed to characterize the nature of abnormalities in cerebral blood flow and the relationship to cognitive deficits in adults with single ventricular physiology. Ten adults with single ventricular physiology (age 18-40 years) and 12 age- and gender-matched controls underwent transcranial Doppler ultrasound and accompanying cognitive assessment. Patients underwent neuropsychological testing that assessed differing cognitive domains, with subjective cognitive decline determined from a 24-question survey. Transcranial Doppler ultrasound was used to assess baseline cerebral blood flow as well as change in cerebral blood flow velocities from baseline and during cognitive testing. Age, ethnicity, in idual, and parental education levels were considered in the multivariate analyses. On assessment of cognitive function, the patient group performed more poorly across each of the measured domains. The control group had a significantly greater increase in cerebral blood flow in response to cognitive stimuli compared to the patient cohort these differences in response to cognitive stimuli were seen to a similar extent across each of the measured cognitive domains. Adults with Fontan physiology are underperforming in assessments of executive function with associated abnormalities in cerebral perfusion potentially contributing to cognitive deficits.
Publisher: Elsevier BV
Date: 12-2020
DOI: 10.1093/JN/NXAA299
Publisher: Cambridge University Press (CUP)
Date: 06-2017
DOI: 10.1017/S1047951117000920
Abstract: Survival into adult life in patients with aortic coarctation is typical following surgical and catheter-based techniques to relieve obstruction. Late sequelae are recognised, including stroke, hypertension, and intracerebral aneurysm formation, with the underlying mechanisms being unclear. We hypothesised that patients with a history of aortic coarctation may have abnormalities of cerebral blood flow compared with controls. Patients with a history of aortic coarctation underwent assessment of cerebral vascular function. Vascular responsiveness of intracranial vessels to hypercapnia and degree of cerebral artery stiffness using Doppler-derived pulsatility indices were used. Response to photic stimuli was used to assess neurovascular coupling, which reflects endothelial function in response to neuronal activation. Patient results were compared with age- and sex-matched controls. A total of 13 adult patients (males=10 77%) along with 13 controls underwent evaluation. The mean age was 36.1±3.7 years in the patient group. Patients with a background of aortic coarctation were noted to have increased pulse pressure on blood pressure assessment at baseline with increased intracranial artery stiffness compared with controls. Patients with a history of aortic coarctation had less reactive cerebral vasculature to hypercapnic stimuli and impaired neurovascular coupling compared with controls. Adult patients with aortic coarctation had increased intracranial artery stiffness compared with controls, in addition to cerebral vasculature showing less responsiveness to hypercapnic and photic stimuli. Further studies are required to assess the aetiology and consequences of these documented abnormalities in cerebral blood flow in terms of stroke risk, cerebral aneurysm formation, and cognitive dysfunction.
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.JDIACOMP.2016.06.025
Abstract: Cognitive deficits in type 2 diabetes mellitus (T2DM) may be partly attributable to stiffness in cerebral arteries and impaired vasodilator function, limiting the ability to increase blood flow in brain regions to meet cognitive demands. We undertook a comparison of cerebrovascular responsiveness (CVR) and cognitive performance in adults with and without T2DM. Older adults with (50) and without (Herath, Cherbuin, Eramudugolla, & Anstey, 2016) T2DM underwent transcranial Doppler ultrasound measurements of basal cerebral mean blood flow velocity (MBFV) and pulsatility index (PI), a measure of arterial stiffness, in the middle cerebral arteries (MCA). A battery of tasks assessing domains of working memory, executive function and information processing/motor speed was then administered while MBFV was recorded. CVR to cognitive tasks was calculated as a percentage increase in MBFV from the basal level. There was no difference in basal MBFV between groups. However, PI was 14% higher in the T2DM group (P<0.05), who performed poorer across all cognitive domains assessed and displayed poorer CVR in three tasks. Cognitive performance was inversely related to the PI/MBFV ratio, an indicator of intracranial stenosis. Impaired cerebral perfusion during mental tasks is accompanied by poor cognitive performance and stiffness in the cerebral vessels.
Publisher: Cold Spring Harbor Laboratory
Date: 12-05-2021
DOI: 10.1101/2021.05.09.21256921
Abstract: Near-infrared spectroscopy (NiRS) is a relatively new technology of brain imaging with its potential in the assessment of cerebrovascular health only recently discovered. Encouraging early results suggest that NiRS can be used as an inexpensive and portable cerebrovascular health tracking device using a recently proposed pulse relaxation function (PReFx). In this paper, we propose a new NiRS timing index, TI NiRS , of cerebrovascular health. TI NiRS is a novel use of the NiRS technology. TI NiRS is motivated by the previously proved relationship of the timing of the reflected wave with vascular resistance and compliance in the context of pressure waveforms. We correlated both TI NiRS and PReFx against age, a non-exercise cardiorespiratory fitness (CRF) index, and two existing indices of cerebrovascular health, namely Transcranial Doppler (TCD) augmentation index, AI TCD , and magnetic resonance imaging (MRI) blood flow pulsatility index, PI MRI . The TI NiRS correlations with Age, CRF, PI MRI and AI TCD all are significant, i.e., r = 0.53 ( p = 0.002), r = −0.44 ( p = 0.011), r = 0.45 ( p = 0.012) and r = 0.46 ( p = 0.010), respectively. PReFx, however, did not have significant correlations with any of the vascular health factors. The proposed timing index is a reliable indicator of cerebrovascular aging factors in the NiRS waveform.
Publisher: MDPI AG
Date: 12-05-2017
DOI: 10.3390/NU9050487
Abstract: Long-chain omega-3 polyunsaturated fatty acids (LCn-3 PUFA) may improve brain functions by acting on endothelial cells in the cerebrovasculature to facilitate vasodilatation and perfusion. The aim of this review is to explore this hypothesis by analyzing the effect of LCn-3 PUFA supplementation on systemic vasodilator and cognitive function and finding evidence to link LCn-3 PUFA intake, vasodilator function and cognition. Forty randomized controlled trials examining the effect of LCn-3 PUFA supplementation in humans on either endothelial vasodilator function or cognition were identified and pooled effects measured with a weighted analysis. Compared to placebo, LCn-3 PUFA tended to increase flow-mediated dilatation and significantly improved cognitive function. Emerging evidence links vasodilator dysfunction to cognitive impairment, but evidence that LCn-3 PUFA can improve cognition through enhancements of vasodilator function is still lacking. Further research is needed to determine: (1) whether LCn-3 PUFA can enhance dilatation of cerebral vessels (2) if improvements in cerebrovascular responsiveness by LCn-3 PUFA are accompanied by cognitive benefits and (3) the target population groups.
Publisher: Wiley
Date: 07-2013
DOI: 10.1111/NYAS.12155
Abstract: Impairments of endothelial function, which can be assessed noninvasively by flow-mediated dilation (FMD) of the brachial artery, contribute to the development of cardiovascular disease. Associations between FMD and cognition suggest a vascular component in the loss of cognitive function. Certain vasoactive nutrients that have been shown to improve FMD may also have the potential to enhance cerebral perfusion and cognition. Preclinical studies show that trans-resveratrol can enhance nitric oxide bioavailability, thereby increasing endothelium-dependent vasodilation. We have now shown that acute administration of resveratrol elicits dose-dependent increases of FMD with greater potency than other vasoactive nutrients and that this benefit is sustained following regular consumption. We describe the potential implications of this vasodilator benefit of resveratrol and its role in enhancing cerebrovascular and cognitive functions.
Publisher: Wiley
Date: 14-07-2020
DOI: 10.1002/JBMR.4115
Publisher: MDPI AG
Date: 03-01-2017
DOI: 10.3390/NU9010027
No related grants have been discovered for Rachel Wong.