Increasing prevalence of hypertension in Hong Kong Cardiovascular Risk Factor Prevalence Study: role of general and central obesity

Introduction: General obesity and central obesity are well-known risk factors of hypertension. We investigated the change in the prevalence of hypertension in the population-based prospective Hong Kong Cardiovascular Risk Factor Prevalence Study (CRISPS) and the relationship of change in blood pressure with change in body mass index (BMI) and waist circumference over a follow-up period of 11.9 years. Methods: A total of 2888, 1942 and 1798 subjects in CRISPS-1 (1995-1996), CRISPS-2 (2000-2004) and CRISPS-3 (2005-2008) were included in this analysis respectively. Hypertension was defined as blood pressure ≥140/90 mm Hg or taking anti-hypertensive medication. General obesity was defined as BMI ≥27.5 kg/m2 and central obesity was defined as waist circumference ≥90 cm in men or ≥80 cm in women. Results: The prevalence of hypertension increased from 18.1% to 39.4% (P<0.001 after adjusting for age and sex). The prevalence of central obesity increased from 25.4% to 41.4%, but that of general obesity decreased from 16.8% to 14.8% (both P<0.001 after adjusting for age and sex). Among 1347 subjects who did not take any anti-hypertensive medication at both CRISPS-1 and CRISPS-3, the change in waist circumference, but not that in BMI, was associated with the changes in both systolic and diastolic blood pressures (beta=0.087, P=0.015 and beta=0.122, P<0.001 respectively). Conclusions: The increase in prevalence of hypertension might be explained by the increase in central obesity. Our findings further confirm the importance of waist circumference in this population; calculating the BMI alone may give a false sense of security. Acknowledgement: This study was funded by Hong Kong Research Grant Council grants (HKU7229/01M and HKU7626/07M) and the Sun Chieh Yeh Heart Foundation.published_or_final_versio

Urotensin II: Its function in health and its role in disease

Urotensin II (U-II) is the most potent vasoconstrictor known, even more potent than endothelin-1. It was first isolated from the fish spinal cord and has been recognized as a hormone in the neurosecretory system of teleost fish for over 30 years. After the identification of U-II in humans and the orphan human G-protein-coupled receptor 14 as the urotensin II receptor, UT, many studies have shown that U-II may play an important role in cardiovascular regulation. Human urotensin II (hU-II) is an 11 amino acid cyclic peptide, generated by proteolytic cleavage from a precursor prohormone. It is expressed in the central nervous system as well as other tissues, such as kidney, spleen, small intestine, thymus, prostate, pituitary, and adrenal gland and circulates in human plasma. The plasma U-II level is elevated in renal failure, congestive heart failure, diabetes mellitus, systemic hypertension and portal hypertension caused by liver cirrhosis. The effect of U-II on the vascular system is variable, depending on species, vascular bed and calibre of the vessel. The net effect on vascular tone is a balance between endothelium-independent vasoconstriction and endothelium-dependent vasodilatation. U-II is also a neuropeptide and may play a role in tumour development. The development of UT receptor antagonists may provide a useful research tool as well as a novel treatment for cardiorenal diseases. © 2005 Springer Science + Business Media, Inc.postprin

Association of genetic variants in gene encoding lipocalin-2 with plasma alanine aminotransferase and aspartate aminotransferase

published_or_final_versionThe 16th Annual Research Conference of the Department of Medicine, The University of Hong Kong, Hong Kong, 22 January 2011. In Hong Kong Medical Journal, 2011, v. 17, suppl. 1, p. 17, abstract no. 1

An optimization model for a battery swapping station in Hong Kong

In this paper, a battery swapping station (BSS) model is proposed as an economic and convenient way to provide energy for the batteries of the electric vehicles (EVs). This method would overcome some drawbacks to the use of electric vehicles like long charging time and insufficient running distance. On the economic concern of a battery swapping station, the station would optimize the availability of the batteries in stock, and at the same time determine the best strategy for recharging the batteries on hand. By optimizing the charging method of the batteries, an optimization model of BSS with the maximum number of batteries in stock has been developed for the bus terminal at the Hong Kong International Airport. The secondary objective would be to minimize a cost on the batteries due to the use of different charging schemes. The genetic algorithm (GA) has been used to implement the optimization model, and simulation results are shown.published_or_final_versio

Role of genetic variants in gene encoding lipocalin-2 in the development of elevated blood pressure

Introduction: Lipocalin-2 is recently recognised as a biomarker of obesity and inflammation, which are both risk factors for hypertension. We therefore investigated the association of common single nucleotide polymorphisms (SNPs) in the gene encoding lipocalin-2 (LCN2) with elevated blood pressure in Hong Kong Chinese. Methods: Five tagging SNPs were genotyped in 1936 subjects from the Hong Kong Cardiovascular Risk Factor Prevalence Study-2 (CRISPS-2) with a median follow-up period of 6.4 years. Elevated blood pressure was defined as ≥130/85 mm Hg or taking anti-hypertensive medication. Results: There were only two haplotypes with frequency of >5%, namely AGATC (45.5%) and GGTCC (41.2%). Haplotype GGTCC was associated with elevated blood pressure at follow-up (OR=1.17 compared to haplotype AGATC, P=0.031 after adjusting for age and sex). Among 1381 subjects without elevated blood pressure at baseline, 321 subjects developed elevated blood pressure at follow-up. Haplotype GGTCC was associated with the development of elevated blood pressure at follow-up (OR=1.30 compared to haplotype AGATC, P=0.011 after adjusting for age, sex, systolic blood pressure, and follow-up duration; OR=1.44, P=0.0015 after further adjusting for other covariates). Among subjects not taking anti-hypertensive medication, carriers of the haplotype GGTCC had higher systolic blood pressure than non-carriers (119.7±16.4 mm Hg vs 117.9±17.3 mm Hg, P=0.043). Conclusion: Our findings suggest, for the first time, that genetic variants in LCN2 may affect blood pressure. Further studies on the role of lipocalin-2 in blood pressure regulation are warranted. Acknowledgement: This study was funded by Hong Kong Research Grant Council grants (HKU7229/01M and HKU7626/07M) and the Sun Chieh Yeh Heart Foundation.published_or_final_versio

Gamma-glutamyl transferase level predicts the development of hypertension in Hong Kong Chinese

Background: Plasma activities of alkaline phosphatase, alanine aminotransferase (ALT), aspartate aminotransferase, and γ-glutamyl transferase (GGT) are often increased in cardiometabolic diseases. We investigated if hypertension is associated with increased activities of these plasma markers. Methods: We included 235 hypertensive and 708 normotensive subjects (mean age 47.3 ± 9.6 and 58.0 ± 10.2. years respectively) from the Hong Kong Cardiovascular Risk Factor Prevalence Study-2 (CRISPS-2) in 2000-2004 who had drank < 1/week. In the follow-up study in 2005-2008 (CRISPS-3), 126 out of the 708 subjects had developed hypertension. Results: Raised plasma ALT (OR = 1.22 per SD of log-transformed level, P=0.045) and GGT (OR = 1.38 per SD of log-transformed level, P=0.001) levels were associated with hypertension at baseline in CRISPS-2 after adjusting for covariates. Among subjects not on anti-hypertensive medications, plasma ALP, ALT and GGT were related to blood pressure (P< 0.01). In subjects normotensive at CRISPS-2, plasma GGT, but not ALP, ALT and AST, was an independent predictor of new-onset hypertension at CRISPS-3 (OR = 1.38 per SD of log-transformed level, P=0.020 and OR = 2.68 for 3rd tertile vs. 1st tertile, P=0.004) after adjusting for covariates. Conclusions: Among the 4 plasma markers, increased GGT activity is the strongest predictor for existing and new-onset hypertension in Hong Kong Chinese. © 2011 Elsevier B.V.postprin

Gamma-glutamyl transferase level predicts the development of hypertension in Hong Kong Chinese

Introduction: Liver enzymes are elevated in cardiometabolic diseases, particularly when there is non-alcoholic fatty liver disease. We therefore investigated if hypertension is associated with elevated levels of alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase and γ-glutamyl transferase (GGT). Methods: We included 235 hypertensive and 708 normotensive subjects from the Hong Kong Cardiovascular Risk Factor Prevalence Study-2 (CRISPS-2) in 2000-2004 who had fewer than one alcoholic drink a week. In the follow-up study in 2005-2008 (CRISPS-3), 126 out of the 708 subjects had developed hypertension. Results: In CRISPS-2, plasma ALT (OR=1.31 per SD of log-transformed level, P=0.005) and GGT (OR=1.52 per SD of log-transformed level, P<0.001) were significantly associated with prevalent hypertension after adjusting for age, sex and body mass index (BMI). Among subjects not on anti-hypertensive medication, plasma ALP and GGT were significantly associated with both systolic blood pressure (beta=0.141, P<0.001 for ALP and beta=0.096, P=0.004 for GGT) and diastolic blood pressure (beta=0.131, P<0.001 for ALP and beta=0.102, P=0.004 for GGT). In forward stepwise logistic regression analysis of subjects normotensive at CRISPS-2, the highest tertile of plasma GGT level was an independent predictor of the development of hypertension in CRISPS-3 (OR=2.40, P=0.010), together with age, BMI, systolic blood pressure and plasma CRP at baseline, and change in BMI. The other liver enzymes were not significantly predictors of new-onset hypertension. Conclusions: Among the four liver enzymes, elevated GGT level is the strongest risk factor for hypertension in Hong Kong Chinese. Acknowledgement: This study was funded by Hong Kong Research Grant Council grants (HKU7229/01M and HKU7626/07M) and the Sun Chieh Yeh Heart Foundation.published_or_final_versio

A study on the effect of testosterone replacement on the development of obstructive sleep apnoea (OSA)

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Association of a genetic variant in adrenomedullin gene with its plasma level

published_or_final_versionThe 16th Annual Research Conference of the Department of Medicine, The University of Hong Kong, Hong Kong, 22 January 2011. In Hong Kong Medical Journal, 2011, v. 17, suppl. 1, p. 19, abstract no. 1

Setting the stage for developing pre-service teachers' conceptions of good science teaching: The role of classroom videos

This paper reports findings about a curriculum innovation conducted at The University of Hong Kong. A CD-ROM consisting of videos of two lessons by different teachers demonstrating exemplary science teaching was used to elicit conceptions of good science teaching of student-teachers enrolled for the 1-year Postgraduate Diploma in Education at several stages during the programme. It was found that the videos elicited student-teachers' conceptions and had impact on those conceptions prior to the commencement of formal instruction. It has extended student-teachers' awareness of alternative teaching methods and approaches not experienced in their own schooling, broadened their awareness of different classroom situations, provided proof of existence of good practices, and prompted them to reflect on their current preconceptions of good science teaching. In several ways, the videos acted as a catalyst in socializing the transition of student-teachers from the role of student to the role of teacher. © 2006 Taylor & Francis.postprin