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ABSTRACT: BACKGROUND AND PURPOSE: Microvascular disease has been implicated in the pathogenesis of stroke. The retina provides a window to assess microcirculation noninvasively. We studied the association between quantitatively measured retinal microvascular characteristics and acute ischemic stroke. METHODS: We conducted a case-control study with acute ischemic stroke patients recruited from a tertiary hospital in Singapore and controls from the Singapore Epidemiology of Eye Disease program matched by 10-year age strata, sex, and race. Strokes were classified using modified Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. Retinal vascular parameters were measured from retinal fundus photographs using a computer program. Logistic regression models for stroke were constructed adjusting for age, sex, race, and additionally for smoking, hypertension, diabetes mellitus, and hypercholesterolemia. RESULTS: We included 557 ischemic stroke cases (261 lacunar, 185 large artery, and 54 cardioembolic stroke) and 557 controls. After adjusting for vascular risk factors, decreased arteriolar fractal dimension (odds ratio [OR] per standard deviation [SD] decrease, 2.28; 95% confidence interval [CI], 1.80-2.87) and venular fractal dimension (OR per SD decrease, 1.80; 95% CI, 1.46-2.23), increased arteriolar tortuosity (OR per SD increase, 1.56; 95% CI, 1.25-1.95), and venular tortuosity (OR per SD increase, 1.49; 95% CI, 1.27-1.76), narrower arteriolar caliber (OR per SD decrease, 2.79; 95% CI, 2.21-3.53), and wider venular caliber (OR per SD increase, 1.57; 95% CI, 1.27-1.95) were associated with stroke. Stratification by stroke subtypes and further adjustment for retinopathy signs revealed similar results. CONCLUSIONS: Patients with ischemic stroke have a sparser and more tortuous microvascular network in the retina. These findings provide insight into the structure and pattern of microcirculation changes in stroke.
Stroke 05/2013; · 5.73 Impact Factor
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ABSTRACT: BACKGROUND: Population-based studies have demonstrated the association of inflammation and cognitive impairment. However, few studies to date have examined this association in ischemic stroke patients. AIMS: The study aims to determine the association between inflammatory markers and cognitive impairment. METHODS: Ischemic stroke patients with baseline neuropsychological assessments at three-months poststroke were followed up with annual neuropsychological assessments for up to five-years. Inflammatory markers (C-reactive protein, interleukin 1β, interleukin 6, interleukin 8, interleukin 10, interleukin 12, and tumor necrosis factor-α) were assayed, and logistic regression analyses were performed to determine associations between inflammatory markers and both baseline cognitive status and subsequent cognitive decline. RESULTS: There were 243 ischemic stroke patients in the study. In multivariable ordinal logistic regression analysis, age, education, ethnicity, stroke subtype, and interleukin 8 (OR 1·23 CI 1·05-1·44) levels were independently associated with baseline cognitive status. In multivariable logistic regression analyses, age, gender, recurrent strokes, and interleukin 12 (OR 25·02 CI 3·73 to 168·03) were independent predictors of subsequent cognitive decline. CONCLUSIONS: Following ischemic stroke, higher serum interleukin 8 is independently associated with baseline cognitive impairment while higher serum interleukin 12 is associated with subsequent cognitive decline.
International Journal of Stroke 03/2013; · 2.38 Impact Factor
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Margherita Cavalieri,
Reinhold Schmidt,
Christopher Chen,
Vincent Mok,
Gabriel R de Freitas,
Swithin Song,
Qilong Yi,
Stefan Ropele,
Anja Grazer,
Nina Homayoon,
Christian Enzinger,
Katherine Loh,
Ka Sing Lawrence Wong,
Adrian Wong,
Yunyun Xiong, Hui Meng Chang,
Meng Cheong Wong,
Franz Fazekas,
John W Eikelboom,
Graeme J Hankey
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ABSTRACT: BACKGROUND AND PURPOSE: Elevated concentrations of homocysteine are associated with cerebral small vessel disease (CSVD). B-vitamin supplementation with folate and vitamins B(12) and B(6) reduces homocysteine concentrations. In a substudy of the VITAmins TO Prevent Stroke (VITATOPS) trial, we assessed the hypothesis that the addition of once-daily supplements of b vitamins would reduce the progression of CSVD-related brain lesions. METHODS: A total of 359 patients with recent stroke or transient ischemic attack, who were randomly allocated to double-blind treatment with placebo or B vitamins, underwent brain MRI at randomization and after 2 years of B-vitamin supplementation. MR images were analyzed blinded to treatment allocation. Outcomes related to the prespecified hypothesis were progression of white matter hyperintensities and incident lacunes. We also explored the effect of B-vitamin supplementation on the incidence of other ischemic abnormalities. RESULTS: After 2 years of treatment with B vitamins or placebo, there was no significant difference in white matter hyperintensities volume change (0.08 vs 0.13 cm(3); P=0.419) and incidence of lacunes (8.0% vs 5.9%, P=0.434; odds ratio=1.38). In a subanalysis of patients with MRI evidence of severe CSVD at baseline, B-vitamin supplementation was associated with a significant reduction in white matter hyperintensities volume change (0.3 vs 1.7 cm(3); P=0.039). CONCLUSIONS: Daily B-vitamin supplementation for 2 years did not significantly reduce the progression of brain lesions resulting from presumed CSVD in all patients with recent stroke or transient ischemic attack but may do so in the subgroup of patients with recent stroke or transient ischemic attack and severe CSVD.Clinical Trial Registration-http://vitatops.highway1.com.au/. Unique identifier: NCT00097669 and ISRCTN74743444.
Stroke 10/2012; · 5.73 Impact Factor
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Deidre Anne De Silva,
Jennifer Justice Frogozo Manzano,
April Toh,
Fung-Peng Woon,
Erica Yang Liu,
Eunizar Omar,
Wan-Xin Wong,
Tien-Yin Wong,
Christopher P L H Chen, Hui-Meng Chang,
Meng-Cheong Wong
International Journal of Stroke 06/2012; 7(4):361-2. · 2.38 Impact Factor
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ABSTRACT: Low ankle-brachial index (ABI), indicative of peripheral arterial disease (PAD), is a risk factor for stroke. ABI has been shown to be associated with cerebral arterial disease and prognosis following stroke. We studied the associations of the degree of ABI lowering with extracranial carotid disease (ECD), intracranial large artery disease (ICLAD), and subsequent vascular events in a prospective cohort of acute ischemic stroke patients.
ABI, extracranial and intracranial cerebral arteries were assessed in a blinded manner. ABI was categorized into 0.9-1.3 (normal), 0.8-0.89 (mildly lowered) and <0.8 (severely lowered). Follow-up data at 1 year were obtained from standardized telephone interviews and verified with medical records.
Among the 1311 patients, 73% had normal ABI, 13% had ABI 0.8-0.89 and 13% had ABI <0.8. Compared to patients with normal ABI, those with ABI<0.8 had higher prevalence of severe ECD (15% vs. 5%, p = 0.006) and ICLAD (72% vs. 48%, p = 0.003), even after adjustment for age, gender, hypertension, diabetes, hyperlipidemia, smoking, ischemic heart disease and atrial fibrillation (severe ECD p < 0.001, ICLAD p < 0.001). At 1 year, patients with ABI <0.8 had a higher incidence of composite vascular events (19% vs. 11%, p = 0.02), stroke (15% vs. 10%, p = 0.06) and myocardial infarction (4% vs. 2%, p = 0.07) than patients with normal ABI.
Among ischemic stroke patients, large cerebral arterial disease and incidence of subsequent vascular events at 1 year were associated with severe ABI lowering <0.8, but not with mild ABI lowering (0.8-0.89).
Atherosclerosis 05/2012; 223(1):219-22. · 3.79 Impact Factor
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Deidre A De Silva,
Jennifer J F Manzano,
Fung-Peng Woon,
Erica Yang Liu,
Moi-Pin Lee,
Hui-Yee Gan,
Christopher P L H Chen, Hui-Meng Chang,
Paul Mitchell,
Jie Jin Wang,
Richard I Lindley,
Tien-Yin Wong,
Meng-Cheong Wong
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ABSTRACT: Intracranial large artery disease (ICLAD) is a major cause of ischemic stroke. Retinal microvascular changes are associated with stroke, including small vessel cerebral disease and extracranial carotid disease. We examined the relationship between ICLAD and retinal microvascular changes.
This is a prospective cohort of 802 acute ischemic stroke patients. Retinal changes were assessed from photographs by graders masked to clinical data. ICLAD was evaluated using prespecified criteria.
ICLAD was not associated with ipsilateral retinal arteriolar/venular caliber, focal arteriolar narrowing, or arteriovenous nicking. Severe enhanced arteriolar light reflex was independently associated with any ICLAD (P=0.006) and severe ICLAD (P<0.001).
Enhanced arteriolar light reflex, but not retinal vessel caliber, was related to ICLAD. These data suggest that retinal microvascular signs have specific associations with large cerebral vessel disease.
Stroke 03/2011; 42(3):812-4. · 5.73 Impact Factor
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ABSTRACT: There is some evidence that poststroke dementia, cognitive impairment no dementia (CIND), and mild cognitive impairment predict for poor outcomes such as dementia, death, and institutionalization. However, few studies have examined the prognostic value of CIND, CIND severity, and domain impairments in a poststroke cohort.
A cohort of ischemic stroke patients with baseline cognitive assessments 3 months poststroke were followed up annually for outcomes of dependency, vascular events, and death for up to 5 years. Univariate and multivariate Cox proportional regression was performed to determine the ability CIND, CIND severity, and domain impairments to predict dependency, vascular outcomes, and death.
Four-hundred nineteen patients without dementia (mean age 60±11 years, 32% female) were followed for a mean of 3.2 years. Older age, diabetes, more severe strokes, CIND-mild, and CIND-moderate were independently predictive of dependency. There were no independent predictors of recurrent vascular events. Older age, diabetes, and CIND-moderate were independently predictive of death. In analyses of individual cognitive domains, impairments in visuomotor speed were independently predictive of dependency.
In poststroke patients, CIND predicts dependency and death, while CIND severity discriminates patients with poor survival. Impairments in visuomotor speed independently predict dependency.
URL: http://clinicaltrials.gov. Unique Identifier: NCT00161070.
Stroke 02/2011; 42(4):883-8. · 5.73 Impact Factor
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ABSTRACT: The effect of genetic factors, apart from 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphisms, on elevated plasma homocysteine levels and increasing ischemic stroke risk have not been fully elucidated. We conducted a comprehensive analysis of 25 genes involved in homocysteine metabolism to investigate association of common variants within these genes with ischemic stroke risk.
The study was done in two stages. In the initial study, SNP and haplotype-based association analyses were performed using 147 tagging Single Nucleotide Polymorphisms (SNPs) in 360 stroke patients and 354 non-stroke controls of Singaporean Chinese ethnicity. Joint association analysis of significant SNPs was then performed to assess the cumulative effect of these variants on ischemic stroke risk. In the replication study, 8 SNPs were selected for validation in an independent set of 420 matched case-control pairs of Singaporean Chinese ethnicity. SNP analysis from the initial study suggested 3 risk variants in the MTRR, SHMT1 and TCN2 genes which were moderately associated with ischemic stroke risk, independent of known stroke risk factors. Although the replication study failed to support single-SNP associations observed in the initial study, joint association analysis of the 3 variants in combined initial and replication samples revealed a trend of elevated risk with an increased number of risk alleles (Joint P(trend) = 1.2×10(-6)).
Our study did not find direct evidence of associations between any single polymorphisms of homocysteine metabolic pathway genes and ischemic stroke, but suggests that the cumulative effect of several small to moderate risk variants from genes involved in homocysteine metabolism may jointly confer a significant impact on ischemic stroke risk.
PLoS ONE 01/2011; 6(9):e24757. · 4.09 Impact Factor
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Alzheimers & Dementia - ALZHEIMERS DEMENT. 01/2011; 7(4).
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ABSTRACT: Intravenous tissue plasminogen activator (tPA) within 3 hours of stroke onset is a licensed proven therapy for ischaemic stroke, with recent trial data showing benefit up to 4.5 hours. We previously published in this journal data of a survey conducted in 2004 showing only 9% of ischaemic stroke patients presenting to the Singapore General Hospital (SGH) arrived within 2 hours of onset. We aimed to determine whether the problem of delayed hospital arrival persists in 2009 and to establish the impact of widening the time window for intravenous tPA to 4.5 hours.
We prospectively surveyed consecutive ischaemic stroke patients admitted to the SGH from 9th March to 30th April 2009. Patients and/or relatives were interviewed with a standardised form similar to the 2004 survey.
Among the 146 ischaemic stroke patients surveyed (median age 67 years, 59% male, median NIHSS score 2), 6% presented to SGH within 2 hours and 15% within 3.5 hours of onset. Median time from stroke onset to hospital arrival was 1245 minutes (20.75 hours). Pre-hospital consultation was significantly associated with hospital arrival after 2 hours from onset. Main reasons cited for delay were not realising the gravity of symptoms (31%) and not recognising them as stroke (27%).
Delayed arrival to SGH following acute ischaemic stroke remains a problem in 2009. This confirms the lack of stroke awareness in Singapore and highlights the need for public stroke education. Furthermore, these data confirm that widening the time window for intravenous tPA treatment to 4.5 hours at SGH will increase its utilisation.
Annals of the Academy of Medicine, Singapore 07/2010; 39(7):513-5. · 1.25 Impact Factor
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Ka Sing Lawrence Wong,
Christopher Chen,
Jianhui Fu, Hui Meng Chang,
Nijasri C Suwanwela,
Yining N Huang,
Zhao Han,
Kay Sin Tan,
Disya Ratanakorn,
Pavithra Chollate,
Yudong Zhao,
Angeline Koh,
Qing Hao,
Hugh S Markus
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ABSTRACT: Few randomised clinical trials have investigated the use of antithrombotic drugs for early secondary prevention of stroke or transient ischaemic attack in patients with intracranial atherosclerotic stenosis. Microembolic signals, detected by transcranial doppler, are a surrogate marker of future stroke risk and have been used to show treatment efficacy in patients with extracranial carotid stenosis. We aimed to investigate whether treatment with clopidogrel plus aspirin reduced the number of microembolic signals detected with transcranial doppler ultrasound compared with aspirin alone in patients with recent stroke.
The clopidogrel plus aspirin for infarction reduction in acute stroke or transient ischaemic attack patients with large artery stenosis and microembolic signals (CLAIR) trial was a randomised, open-label, blinded-endpoint trial. Between Oct 28, 2003, and Nov 19, 2008, patients with acute ischaemic stroke or transient ischaemic attack who had symptomatic large artery stenosis in the cerebral or carotid arteries and in whom microembolic signals were present on transcranial doppler were randomly assigned within 7 days of symptom onset to receive clopidogrel (300 mg for the first day, then 75 mg daily) plus aspirin (75-160 mg daily) or aspirin alone (75-160 mg daily) for 7 days. Patients were randomly assigned in blocks of four or six by use of a randomisation website. Monitoring of microembolic signals on transcranial doppler was done on days 2 and 7. The primary endpoint was the proportion of patients who had microembolic signals on day 2. Analysis was by modified intention to treat. All analyses were done by an investigator masked to both patient identity and the day the recording was taken. This trial is registered with the Centre for Clinical Trials, Chinese University of Hong Kong, number CUHK_CCT00164.
100 patients were randomly assigned to clopidogrel plus aspirin (n=47) or aspirin monotherapy (n=53). 93 of 100 patients had symptomatic intracranial stenosis in either the intracranial internal carotid artery or the middle cerebral artery: 45 of 46 in the dual therapy group and 48 of 52 in the monotherapy group. At day 2, 14 of 45 patients in the dual therapy group and 27 of 50 patients in the monotherapy group for whom data were available had at least one microembolic signal on transcranial doppler (relative risk reduction 42.4%, 95% CI 4.6-65.2; p=0.025). Adverse events were similar in the two groups. No patients had intracranial or severe systemic haemorrhage, but two patients in the dual therapy group had minor haemorrhages.
Combination therapy with clopidogrel and aspirin is more effective than aspirin alone in reducing microembolic signals in patients with predominantly intracranial symptomatic stenosis. Clinical trials are now warranted to investigate whether this combination treatment also results in a reduction in stroke incidence.
The Lancet Neurology 03/2010; 9(5):489-97. · 23.46 Impact Factor
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ABSTRACT: Previous clinical trials have shown that Neuroaid (MLC601), a traditional Chinese medicine, shows good tolerability and superiority over another traditional Chinese medicine in terms of neurological disability and functional outcome and thus may be beneficial as part of a poststroke rehabilitation program. The safety of MLC601 on hemostasis, hematology and biochemistry has been established in normal subjects and patients with nonacute stroke over a short treatment period. We assessed the safety of Neuroaid in patients with acute stroke treated for 3 months in a substudy of an ongoing randomized placebo-controlled trial.
Laboratory tests (biochemical, hematological and electrocardiogram) were conducted at the month 3 follow-up, in addition to baseline tests. A total of 114 patients were recruited. As there were 13 dropouts, a total of 52 patients on MLC601 and 49 on placebo were available for analysis. Serious adverse events (SAEs) were also analyzed.
There were no statistically or clinically significant differences between treatment groups in biochemical, hematological or electrocardiogram tests at month 3, nor any statistically or clinically significant differences in the absolute and relative changes of the various parameters between baseline and 3 months. SAEs were similar and were those commonly seen in stroke patients.
Longer-term laboratory safety data show no differences between MLC601 and placebo, confirming the safety of MLC601 in acute stroke patients receiving a 3-month treatment.
Cerebrovascular Diseases 01/2010; 30(1):1-6. · 2.72 Impact Factor
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Deidre A De Silva,
Gerald Liew,
Meng-Cheong Wong, Hui-Meng Chang,
Christopher Chen,
Jie Jin Wang,
Michelle L Baker,
Peter J Hand,
Elena Rochtchina,
Erica Yang Liu,
Paul Mitchell,
Richard I Lindley,
Tien Yin Wong
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ABSTRACT: Previous studies show that both retinal vascular caliber and carotid disease predict incident stroke in the general population, but the exact relationship between these 2 microvascular and macrovascular structural risk factors is unclear. We studied the relationship between retinal vascular caliber and carotid disease in patients presenting with acute ischemic stroke.
We conducted a cross-sectional study of patients with acute ischemic stroke recruited from 3 centers (Melbourne, Sydney, Singapore). The caliber of retinal arterioles and venules was measured from digital retinal photographs. Severe extracranial carotid disease was defined as stenosis >or=75% or occlusion determined by carotid Doppler using North American Symptomatic Carotid Endarterectomy Trial-based criteria.
Among the 1029 patients with acute stroke studied, 7% of the population had severe extracranial carotid disease. Retinal venular caliber was associated with ipsilateral severe carotid disease (P<0.001 in multivariate models). Patients with wider retinal venular caliber were more likely to have severe ipsilateral carotid disease (multivariable-adjusted OR, 3.81; 95% CI, 1.80 to 8.07, comparing the largest and smallest venular caliber quartiles). The retinal venular caliber-carotid disease association remained significant in patients with large artery stroke.
In patients with acute stroke, retinal venular widening was strongly associated with ipsilateral severe extracranial carotid disease. Our findings suggest concomitant retinal and cerebral microvascular disease may be present in patients with carotid stenosis or occlusion disease. The pathogenesis of stroke due to carotid disease may thus be partially mediated by microvascular disease.
Stroke 10/2009; 40(12):3695-9. · 5.73 Impact Factor
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Stroke 10/2009; 40(10):e594; author reply e595. · 5.73 Impact Factor
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ABSTRACT: This study aims to analyse the results of carotid stenting in a tertiary referral centre in Singapore.
Retrospective analysis of all carotid artery stenting (CAS) cases in a single centre from March 1997 to December 2008 was performed. Sixty successful procedures were performed in 61 patients, with bilateral stenting in 1 patient, and 2 failed procedures. The majority were Chinese (78.7%) and males (77.0%), with a high proportion having hypertension (82.0%) and hypercholesterolaemia (78.7%). The majority (91.8%) of patients were high surgical risk candidates, primarily due to cardiac risk factors. Ten patients (16.4%) had prior neck irradiation for nasopharyngeal carcinoma, and 3 patients each (4.9%) had previous endarterectomy and contralateral occlusion. A distal embolic protection device was used in 71.7% of cases.
Technical success was 96.8%. The 30-day stroke and death rate was 13.8%, comparable to reported results for this high surgical risk population.
CAS is a technically feasible and a relatively safe alternative to endarterectomy to treat extracranial carotid stenosis, especially in patients who are inoperable or at high surgical risk.
Annals of the Academy of Medicine, Singapore 09/2009; 38(9):756-62. · 1.25 Impact Factor
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Richard I Lindley,
Jie Jin Wang,
Meng-Cheong Wong,
Paul Mitchell,
Gerald Liew,
Peter Hand,
Joanna Wardlaw,
Deidre A De Silva,
Michelle Baker,
Elena Rochtchina,
Christopher Chen,
Graeme J Hankey, Hui-Meng Chang,
Victor S C Fung,
Lavier Gomes,
Tien Y Wong
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ABSTRACT: Lacunar stroke accounts for a quarter of cases of acute ischaemic stroke; however, its underlying pathophysiology remains unclear. Our aim was to establish whether there is an association between changes in the retinal microvasculature and lacunar stroke that might provide clues to the pathology of cerebral small vessel disease.
In this cross-sectional study, we recruited patients who presented with acute stroke at three centres in two countries (Sydney and Melbourne, Australia, and Singapore). Each patient had standardised clinical assessments, retinal photography, and CT or MRI of the brain. Changes in the retinal microvasculature were assessed from retinal photographs by graders who were masked to the patients' clinical details. Lacunar stroke was diagnosed according to a modified version of the TOAST criteria (Treatment of Acute Stroke Trial) or the OCSP criteria (Oxfordshire Community Stroke Project) and by MRI findings.
We recruited 1321 patients aged 19 to 94 years with acute ischaemic stroke; 410 (31%) had lacunar stroke. Patients with acute lacunar stroke were no more likely to have hypertension (p=0.12), diabetes (p=0.51), or hypercholesterolaemia (p=0.91) than were patients with other types of ischaemic stroke. However, patients with lacunar stroke were more likely to have retinal microvessel signs, particularly when stroke subtype was confirmed using diffusion-weighted MRI, than were patients with other stroke subtypes. After adjustment for age, sex, study site, smoking history, hypertension, and diabetes, the patients with lacunar stroke were more likely than those with other stroke subtypes to have microvessel signs, and when stroke subtype was confirmed by diffusion-weighted MRI the odds ratios were: 3.55 (95% CI 1.77-7.12) for focal arteriolar narrowing; 1.96 (1.19-3.24) for arteriovenous nipping; 2.32 (1.42-3.79) for enhanced light reflex of the arteriolar wall; 1.33 (0.74-2.41) for generalised retinal arteriolar narrowing; 1.45 (0.84-2.51) for small retinal arteriole:venule ratio; and 1.35 (0.80-2.26) for retinal venular widening.
Our findings suggest that acute lacunar stroke is a manifestation of non-atherothrombotic occlusive small vessel disease, which might have implications for the prevention and treatment of this stroke subtype.
National Health and Medical Research Council of Australia; National Medical Research Council of Singapore; Scottish Funding Council; New South Wales Health.
The Lancet Neurology 08/2009; 8(7):628-34. · 23.46 Impact Factor
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ABSTRACT: Contrasting observations have been made between serum urate and ischemic stroke outcomes in studies involving Caucasian populations. To assess the hypothesis that urate is associated with stroke outcomes, a prospective follow-up study was performed in a cohort of Asian patients with ischemic stroke. Patients diagnosed with transient ischemic attack, first or recurrent ischemic stroke were included in this study. Serum urate, measured using high-performance liquid chromatography, was correlated with 12-month functional and vascular stroke outcomes. Poor functional outcome was defined as a modified Rankin scale exceeding 2 and vascular outcome was defined as a composite of recurrent stroke, myocardial infarction or vascular death during the study period. A total of 503 patients of mean age 63 (SD 12) years were included. A U-shaped relationship between urate quartiles and poor functional outcomes was demonstrated. More patients with low (<280microM) and high (>410microM) urate levels had poor functional outcomes (36% and 27% respectively), compared to those with urate levels between 340 and 410microM (14%). No significant relationship was observed between urate and vascular outcomes. Depending on its level, serum urate may exhibit protective and deleterious effects on stroke outcomes.
Atherosclerosis 08/2009; 209(1):215-9. · 3.79 Impact Factor
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ABSTRACT: Family history is a known non-modifiable risk factor of stroke. We aimed to compare the frequency of a family history of vascular disease between ethnic South Asian and Chinese stroke patients. We studied consecutive ethnic South Asian and Chinese ischaemic stroke patients matched for age, gender and presence of diabetes. Among the 152 matched pairs, ethnic South Asian ischaemic stroke patients had a higher frequency of vascular family history (IHD OR 3.465 p<0.001; CVD OR 1.754 p=0.059; and either IHD or CVD OR 2.169 p=0.003) compared to matched ethnic Chinese patients, independent of past IHD history and stroke subtype. In the ethnic South Asian cohort, patients < or = 60 years old had a higher frequency of a family history of IHD (37% vs 13%, p<0.001), CVD (34% vs 15%, p=0.005) and either IHD or CVD (52% vs 25%, p<0.001) compared to those >60 years. Family history of vascular disease is common among ethnic South Asian ischaemic stroke patients, particularly among those < or = 60 years old. We postulate that the higher frequency of a vascular family history among ethnic South Asians compared to ethnic Chinese may be explained by genetic, environmental and lifestyle influences, or interactions between these factors.
Journal of the neurological sciences 07/2009; 285(1-2):118-20. · 2.32 Impact Factor
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ABSTRACT: Objective: Intracranial large artery disease (ICLAD) is a common stroke subtype that carries a poor prognosis. We studied the association of arterial stiffness, a recognized risk factor for atherosclerosis and ICLAD among ethnic Chinese and South Asian ischemic stroke patients.
Methods: In this prospective study, we recruited consecutive ischemic stroke patients of Chinese and South Asian ethnicity. ICLAD was assessed by transcranial color-coded Doppler or magnetic resonance angiographic studies. Arterial stiffness was measured by carotid-femoral pulse wave velocity (cPWV).
Results: Among the 268 patients studied, the prevalence of ICLAD was 54% and median cPWV was 11.4 m/s (interquartile range 9.0-13.6 m/s). Patients with ICLAD had higher cPWV compared with those without (median 11.7 vs. 11.0 m/s, P = 0.015). In multivariate analysis, patients with ICLAD were significantly more likely to have cPWV measurements in the highest quintile (>14.1 m/s) compared with patients without ICLAD independently of other covariates [odds ratio 2.21, P = 0.038].
Conclusion: This study revealed a novel association between arterial stiffness and ICLAD among ischemic stroke patients. The findings suggest that arterial stiffness may be involved in the pathophysiology of ICLAD. Future studies should investigate the effects of reducing arterial stiffness among stroke patients with ICLAD.
Journal of Hypertension 06/2009; 27(7):1453-1458. · 4.02 Impact Factor
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ABSTRACT: Increased total homocysteine (tHcy) is a risk factor for stroke. This study examines whether the efficacy of B-vitamins in reducing tHcy is modified by ethnicity in a Singaporean ischemic stroke population.
505 patients (419 Chinese, 41 Malays and 45 Indians) with ischemic stroke were randomized to receive placebo or B-vitamins. Fasting blood samples collected at baseline and 1 year were assayed for tHcy. MTHFR polymorphisms were genotyped.
Ethnicity did not independently determine tHcy at baseline. The magnitude of tHcy reduction by B-vitamin treatment was consistent across ethnic groups (Chinese -3.8+/-4.5, Malay -4.9+/-4.2, and Indian -3.3+/-3.6 micromol/L) despite ethnic differences in MTHFR genotype and baseline folic acid (FA) and vitamin B(12) (vitB(12)) concentrations.
Ethnicity does not appear to affect the tHcy-lowering effect of B-vitamins, despite differences in dietary intake and prevalence of MTHFR polymorphisms. This suggests that the effect of B-vitamins in lowering tHcy is generalizable across Asian populations. However, due to relatively small numbers of non-Chinese studied, confirmation in other populations is required.
Stroke 05/2009; 40(6):2209-11. · 5.73 Impact Factor
