ORCID Profile
0000-0002-8657-2418
Current Organisations
Higher Education Academy
,
Hong Kong College of Physicians
,
Hong Kong Academy of Medicine (Medicine)
,
University of Oxford
,
Hong Kong College of Physicians (Neurology)
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Publications
Dietary intake of phytoestrogen is associated with increased circulating endothelial progenitor cells in patients with cardiovascular disease
Publisher: Oxford University Press (OUP)
Date: 14-02-2011
Abstract: Endogenous estrogen is known to positively influence the level and functionality of endothelial progenitor cells (EPC). However, the effect of phytoestrogen on EPC is unknown. Isoflavone is a major component of phytoestrogen. This study aims to investigate if the intake of isoflavone has any impact on the circulating level of EPC. We studied 102 consecutive patients (mean age: 66.5 ± 9.5 years, 78% male, all female post-menopausal) with cardiovascular disease (atherothrombotic stroke 62%, coronary artery disease 38%). Circulating levels of CD133(+) EPC were determined by flow cytometry. Non-invasive pulse wave velocity (PWV) was measured. Long-term intake of isoflavone was determined by a validated food frequency questionnaire. Isoflavone intake was positively associated with circulating CD133(+) EPC (r = 0.31, p = 0.001). Patients with circulating CD133(+) EPC <10th percentile had significantly lower isoflavone intake than patients with CD133(+)EPC ≥10th percentile (4.6 ± 3.7 mg/day versus 19.3 ± 30.2 mg/day, p 0.05). Furthermore, circulating CD133(+) EPC <10th percentile was independently predictive of increased PWV by 261.7 cm/s (95% CI: 37.1 to 486.2, p = 0.024). The study demonstrated that circulating EPC increased by more than one fold in patients with cardiovascular disease who had higher intake of isoflavone, suggesting that isoflavone may confer vascular protection through enhanced endothelial repair.
ChatGPT versus human in generating medical graduate exam questions – An international prospective study
Publisher: Cold Spring Harbor Laboratory
Date: 16-05-2023
DOI: 10.1101/2023.05.13.23289943
Abstract: This is a prospective study on the quality of multiple-choice questions (MCQs) generated by the language model ChatGPT for the use in medical graduate examination. 50 MCQs were generated by ChatGPT with reference to two standard undergraduate medical textbooks (Harrison’s, and Bailey & Love’s). Another 50 MCQs were drafted by two university professoriate staffs using the same medical textbooks. All 100 MCQ were in idually numbered, randomized and sent to five independent international assessors for MCQ quality assessment using a standardized assessment score on five assessment domains namely, appropriateness of the question, clarity and specificity, relevance, discriminative power of alternatives, and suitability for medical graduate examination. The total time required for ChatGPT to create the 50 questions was 20 minutes 25 seconds while it took two human examiners a total of 211 minutes 33 seconds for drafting the 50 questions. When a comparison of the mean score was made between the questions constructed by AI with those drafted by human, only in the relevance domain that the AI was inferior to human (AI: 7.56 +/- 0.94 vs human: 7.88 +/- 0.52 p = 0.04). There was no significant difference in question quality between questions drafted by AI versus human, in the total assessment score as well as in other domains. Questions generated by AI yielded a wider range of scores while those created by human were consistent and within a narrower range. ChatGPT has the potential to generate comparable-quality MCQs for medical graduate examination within a significantly shorter time.
Reduction of C-reactive protein with isoflavone supplement reverses endothelial dysfunction in patients with ischaemic stroke
Publisher: Oxford University Press (OUP)
Date: 30-05-2008
Abstract: To investigate the effect of oral isoflavone supplement on vascular endothelial function in patients with established cardiovascular disease. A randomized, double-blinded, placebo-controlled trial was performed to determine the effects of isoflavone supplement (80 mg/day, n = 50) vs. placebo (n = 52) for 12 weeks on brachial flow-mediated dilatation (FMD) in patients with prior ischaemic stroke. Compared with controls, FMD at 12 weeks was significantly greater in isoflavone-treated patients [treatment effect 1.0%, 95% confidence interval (95% CI) 0.1-2.0, P = 0.035]. Adjusted for baseline differences in FMD, isoflavone treatment was independently associated with significantly less impairment of FMD at 12 weeks (odds ratio 0.32, 95% CI 0.13-0.80, P = 0.014). The absolute treatment effect of isoflavone on brachial FMD was inversely related to baseline FMD (r = -0.51, P 0.05). This study demonstrated that 12 week isoflavone treatment reduced serum hs-C-reactive protein and improved brachial FMD in patients with clinically manifest atherosclerosis, thus reversing their endothelial dysfunction status. These findings may have important implication for the use of isoflavone for secondary prevention in patients with cardiovascular disease, on top of conventional interventions.
Sex Differences in Association Between Gut Microbiome and Essential Hypertension Based on Ambulatory Blood Pressure Monitoring
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2023
DOI: 10.1161/HYPERTENSIONAHA.122.20752
Abstract: Sex differences in the pathogenesis of hypertension exist. While gut microbiota (GM) has been associated with hypertension, it is unclear whether there are sex-linked differences in the association between GM and hypertension. We conducted a cross-sectional study to investigate the sex differences in associations between GM characterized by shotgun sequencing, GM-derived short-chain fatty acids, and 24-hour ambulatory blood pressure in 241 Hong Kong Chinese (113 men and 128 women mean age, 54±6 years). The hypertensive group was associated with GM alterations however, significant differences in β- ersity and GM composition in hypertensive versus normotensive groups were only observed in women and not in men under various statistical models adjusting for the following covariates: age, sex, body mass index, sodium intake estimated by spot urine analysis, blood glucose, triglycerides, low- and high-density lipoprotein cholesterol, smoking, menopause, and fatty liver status. Specifically, Ruminococcus gnavus , Clostridium bolteae , and Bacteroides ovatus were significantly more abundant in the hypertensive women, whereas Dorea formicigenerans was more abundant in the normotensive women. No bacterial species were found to be significantly associated with hypertension in men. Furthermore, total plasma short-chain fatty acids and propionic acid were independent predictors of systolic and diastolic blood pressure in women but not men. GM dysregulation was strongly associated with 24-hour ambulatory blood pressure in women but not men, which may be mediated through propionic acid. Our work suggests that sex differences may be an important consideration while assessing the role of GM in the development and treatment of hypertension.
Association between the risk of seizure and COVID‐19 vaccinations: A self‐controlled case‐series study
Publisher: Wiley
Date: 29-10-2022
DOI: 10.1111/EPI.17436
Abstract: The risk of seizure following BNT162b2 and CoronaVac vaccinations has been sparsely investigated. This study aimed to evaluate this association. Patients who had their first seizure‐related hospitalization between February 23, 2021 and January 31, 2022, were identified in Hong Kong. All seizure episodes happening on the day of vaccination (day 0) were excluded, since clinicians validated that most of the cases on day 0 were syncopal episodes. Within‐in idual comparison using a modified self‐controlled case series analysis was applied to estimate the incidence rate ratio (IRR) with 95% confidence intervals (CIs) of seizure using conditional Poisson regression. We identified 1656 in iduals who had their first seizure‐related hospitalization (BNT162b2: 426 CoronaVac: 263 unvaccinated: 967) within the observation period. The incidence of seizure was 1.04 (95% CI .80–1.33) and 1.11 (95% CI .80–1.50) per 100 000 doses of BNT162b2 and CoronaVac administered, respectively. Sixteen and 17 in iduals, respectively, received a second dose after having a first seizure within 28 days after the first dose of BNT162b2 and CoronaVac vaccinations. None had recurrent seizures after the second dose. There was no increased risk during day 1–6 after the first (BNT162b2: IRR = 1.39, 95% CI = .75–2.58 CoronaVac: IRR = 1.19, 95% CI = .50–2.83) and second doses (BNT162b2: IRR = 1.36, 95% CI = .72–2.57 CoronaVac: IRR = .71, 95% CI = .22–2.30) of vaccinations. During 7–13, 14–20, and 21–27 days post‐vaccination, no association was observed for either vaccine. The findings demonstrated no increased risk of seizure following BNT162b2 and CoronaVac vaccinations. Future studies will be warranted to evaluate the risk of seizure following COVID‐19 vaccinations in different populations, with subsequent doses to ensure the generalizability .
Stroke Risk and Antithrombotic Treatment During Follow-up of Patients With Ischemic Stroke and Cortical Superficial Siderosis
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 21-03-2201
DOI: 10.1212/WNL.0000000000201723
Abstract: In patients with ischemic stroke (IS) or transient ischemic attack (TIA) and cortical superficial siderosis (cSS), there are few data regarding the risk of future cerebrovascular events and also about the benefits and safety of antithrombotic drugs for secondary prevention. We investigated the associations of cSS and stroke risk in patients with recent IS or TIA. We retrospectively analyzed the Microbleeds International Collaborative Network (MICON) database. We selected patients with IS or TIA from cohorts who had MRI-assessed cSS, available data on antithrombotic treatments, recurrent cerebrovascular events (intracranial hemorrhage [ICrH], IS, or any stroke [ICrH or IS]), and mortality. We calculated incidence rates (IRs) and performed univariable and multivariable Cox regression analyses. Of 12,669 patients (mean age 70.4 ± 12.3 years, 57.3% men), cSS was detected in 273 (2.2%) patients. During a mean follow-up of 24 ± 17 months, IS was more frequent than ICrH in both cSS (IR 57.1 vs 14.6 per 1,000 patient-years) and non-cSS (33.7 vs 6.3 per 1,000 patient-years) groups. Compared with the non-cSS group, cSS was associated with any stroke on multivariable analysis {IR 83 vs 42 per 1,000 patient-years, adjusted hazard ratio [HR] for cSS 1.62 (95% CI: 1.14–2.28 p = 0.006)}. This association was not significant in subgroups of patients treated with antiplatelet drugs (n = 6,554) or with anticoagulants (n = 4,044). Patients with cSS who were treated with both antiplatelet drugs and anticoagulants (n = 1,569) had a higher incidence of ICrH (IR 107.5 vs 4.9 per 1,000 patient-years, adjusted HR 13.26 95% CI: 2.90–60.63 p = 0.001) and of any stroke (IR 198.8 vs 34.7 per 1,000 patient-years, adjusted HR 5.03 95% CI: 2.03–12.44 p 0.001) compared with the non-cSS group. Patients with IS or TIA with cSS are at increased risk of stroke (ICrH or IS) during follow-up the risk of IS exceeds that of ICrH for patients receiving antiplatelet or anticoagulant treatment alone, but the risk of ICrH exceeds that of IS in patients receiving both treatments. The findings suggest that either antiplatelet or anticoagulant treatment alone should not be avoided in patients with cSS, but combined antithrombotic therapy might be hazardous. Our findings need to be confirmed by randomized clinical trials.
Age-Biomarkers-Clinical Risk Factors for Prediction of Cardiovascular Events in Patients With Coronary Artery Disease
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2018
DOI: 10.1161/ATVBAHA.118.311726
Abstract: In patients with stable coronary artery disease, conventional risk factors provide limited incremental predictive value for cardiovascular events. We sought to investigate whether a panel of cardiometabolic biomarkers alone or combined with conventional risk factors would exhibit incremental value in the prediction of cardiovascular events. In the discovery cohort, we measured serum adiponectin, A-FABP (adipocyte fatty acid–binding protein), lipocalin-2, FGF (fibroblast growth factor)-19 and 21, plasminogen activator inhibitor-1, and retinol-binding protein-4 in 1166 Chinese coronary artery disease patients. After a median follow-up of 35 months, 170 patients developed new-onset major adverse cardiovascular events (MACE). In the model with age ≥65 years and conventional risk factors, area under the curve for predicting MACE was 0.68. Addition of lipocalin-2 to the age-clinical risk factor model improved predictive accuracy (area under the curve=0.73). Area under the curve further increased to 0.75 when a combination of lipocalin-2, A-FABP, and FGF-19 was added to yield age-biomarkers-clinical risk factor model. The adjusted hazard ratio on MACEs for lipocalin-2, A-FABP, and FGF-19 levels above optimal cutoffs were 2.23 (95% CI, 1.62–3.08), 1.99 (95% CI, 1.43–2.76), and 1.65 (95% CI, 1.15–2.35), respectively. In the validation cohort of 1262 coronary artery disease patients with type 2 diabetes mellitus, the age-biomarkers-clinical risk factor model was confirmed to provide good discrimination and calibration over the conventional risk factor alone for prediction of MACE. A combination of the 3 biomarkers, lipocalin-2, A-FABP, and FGF-19, with clinical risk factors to yield the age-biomarkers-clinical risk factor model provides an optimal and validated prediction of new-onset MACE in patients with stable coronary artery disease.
Cerebral microbleeds and stroke risk after ischaemic stroke or transient ischaemic attack: a pooled analysis of individual patient data from cohort studies
Publisher: Elsevier BV
Date: 07-2019
Related Organisations
Higher Education Academy
Location: United Kingdom of Great Britain and Northern Ireland
University Of Oxford
Location: United Kingdom of Great Britain and Northern Ireland
Related Funding Activities
No related grants have been discovered for Gary Kui Kai Lau.