Search PubMed⌕ Search

Biomedical subjects

T H Lam

Publications and source records attributed to T H Lam.

At least 37 records · Page 2Linked to original sources
PubMed2005

Ethnic comparisons of obesity in the Asia-Pacific region: protocol for a collaborative overview of cross-sectional studies.

The prevalence of overweight and obesity has been rapidly increasing within countries of the Asia-Pacific region, with adverse consequences for health. The Obesity in Asia Collaboration (OAC) was initiated to provide reliable evidence concerning the relationships between anthropometrical markers of adiposity with cardiovascular risk factors within, and across, ethnic groups. This is to be achieved through the collection of cross-sectional studies from the Asia-Pacific region. These data will be used to examine the ethnic-specific associations of different anthropometric measures of adiposity (such as body mass index, waist circumference, waist-hip ratio and waist-height ratio) with cardiovascular risk factors (fasting blood glucose and blood pressure). Estimates of the relative risks for type 2 diabetes and hypertension with increased adiposity will be obtained using data from contributing studies in conjunction with those from the previously established Asia Pacific Cohort Studies Collaboration. To date, 12 countries and regions from the Asia-Pacific region with information on nearly 300,000 individuals, are participants in the OAC. Data from other eligible studies are sought. The findings from the OAC will provide reliable evidence concerning the association of adiposity with cardiovascular risk factors across ethnic groups. It will also provide a strong evidence base upon which to define ethnic-specific cut-points for overweight and obesity.

Anthropometry↗
PubMed2005

Overweight, obesity, weight-related concerns and behaviours in Hong Kong Chinese children and adolescents.

AIM: To study the prevalence of overweight and obesity, and weight-related concerns and behaviours among overweight, obese and non-overweight children and adolescents. METHODS: We carried out a cross-sectional survey of all Chinese students in primary schools in the Central and Western District of Hong Kong in March 2002. Thirty-one of 32 schools participated, and 5402 boys and 5371 girls aged 8 to 15 y who completed a standardized questionnaire were included. We used the International Obesity Task Force definition (IOTF reference) to define overweight and obesity. RESULTS: The prevalence (95% CI) of overweight was 16.4% (15.7-17.1%) (19.9% in boys, 12.9% in girls), and that of obesity was 7.7% (7.2-8.2%) (10.3% in boys and 5.1% in girls). The combined prevalence of overweight and obesity was similar to that based on the local reference. Overweight children had more concerns about their weight than obese children. They were more likely than obese children to feel fat, wish to be lighter, diet and exercise to lose weight. Although obese children were heavier, they did not make more effort to lose weight than overweight children. CONCLUSIONS: The differences in weight-related concerns and behaviours among overweight, obese and non-overweight children suggested good validity of the IOTF reference and the self-reported data. The differences between overweight and obese children suggested that the two groups had different psychological states and that they needed different weight management programmes and other intervention strategies.

Adolescent↗
PubMed2005

Surveillance of acute flaccid paralysis in Hong Kong: 1997 to 2002.

OBJECTIVES: To describe the characteristics of patients reported with acute flaccid paralysis between 1997 and 2002, and to evaluate the performance of the acute flaccid paralysis surveillance system using indicators recommended by the World Health Organization. DESIGN: Retrospective study. SETTING: Department of Health, Hong Kong. PARTICIPANTS: Children aged younger than 15 years who were reported to the Department of Health between 1997 and 2002 with acute flaccid paralysis. RESULTS: Of 120 children with acute flaccid paralysis reported between 1997 and 2002, 42% were younger than 5 years of age. None of the cases were acute poliomyelitis or polio-compatible. A neurological cause was identified in 67.5% of cases, of which the most common was Guillain-Barre syndrome (42%), followed by transverse myelitis (15%). All except one of the performance indicators consistently met World Health Organization requirements and thus demonstrated the effectiveness of the acute flaccid paralysis surveillance programme. The acute flaccid paralysis notification rate consistently exceeded 1.0 per 100 000 population below 15 years of age. The requirement for adequate stool investigation was the single indicator that did not satisfy World Health Organization requirements. This highlighted the importance of maintaining physicians' awareness of acute flaccid paralysis surveillance. CONCLUSION: Hong Kong should remain vigilant for acute flaccid paralysis. The effective surveillance system and its evaluation may serve as a model for surveillance of other infectious diseases.

Acute Disease↗
PubMed2004

Serum triglycerides as a risk factor for cardiovascular diseases in the Asia-Pacific region.

BACKGROUND: The importance of serum triglyceride levels as a risk factor for cardiovascular diseases is uncertain. METHODS AND RESULTS: We performed an individual participant data meta-analysis of prospective studies conducted in the Asia-Pacific region. Cox models were applied to the combined data from 26 studies to estimate the overall and region-, sex-, and age-specific hazard ratios for major cardiovascular diseases by fifths of triglyceride values. During 796,671 person-years of follow-up among 96,224 individuals, 670 and 667 deaths as a result of coronary heart disease (CHD) and stroke, respectively, were recorded. After adjustment for major cardiovascular risk factors, participants grouped in the highest fifth of triglyceride levels had a 70% (95% CI, 47 to 96) greater risk of CHD death, an 80% (95% CI, 49 to 119) higher risk of fatal or nonfatal CHD, and a 50% (95% CI, 29% to 76%) increased risk of fatal or nonfatal stroke compared with those belonging to the lowest fifth. The association between triglycerides and CHD death was similar across subgroups defined by ethnicity, age, and sex. CONCLUSIONS: Serum triglycerides are an important and independent predictor of CHD and stroke risk in the Asia-Pacific region. These results may have clinical implications for cardiovascular risk prediction and the use of lipid-lowering therapy.

Aged↗
PubMed2004

Epidemiology, transmission dynamics and control of SARS: the 2002-2003 epidemic.

This paper reviews current understanding of the epidemiology, transmission dynamics and control of the aetiological agent of severe acute respiratory syndrome (SARS). We present analyses of data on key parameters and distributions and discuss the processes of data capture, analysis and public health policy formulation during the SARS epidemic are discussed. The low transmissibility of the virus, combined with the onset of peak infectiousness following the onset of clinical symptoms of disease, transpired to make simple public health measures, such as isolating patients and quarantining their contacts, very effective in the control of the SARS epidemic. We conclude that we were lucky this time round, but may not be so with the next epidemic outbreak of a novel aetiological agent. We present analyses that help to further understanding of what intervention measures are likely to work best with infectious agents of defined biological and epidemiological properties. These lessons learnt from the SARS experience are presented in an epidemiological and public health context.

Age Factors↗
PubMed2004

Binary latent variable modelling and its applicationin the study of air pollution in Hong Kong.

A binary latent variable is constructed to account for the correlation between multiple binary outcomes and is treated as a dependent variable in modelling for covariate effects. This modelling method is similar to the structural equation modelling. Three models are considered: (1) all covariates affecting the binary latent variable directly; (2) some covariates affecting the binary latent variable while other affecting the manifestation of the binary outcomes; and (3) no covariates are included. Gibbs sampling, a special case of the Markov Chain Monte Carlo method, is used to estimate the parameters in the models. Simulation studies show that this method is valid and reliable in estimating covariate effects. But Model (1) fitted the data best with lowest value in the deviance information criteria. The method is illustrated by applying it to the data analysis of an environmental air pollution study. The results show that air pollution (i.e. the most versus the least polluted district) (odds ratio 1.20; 95% confidence interval 0.97-1.49; p=0.102), smoking (relative to not smoking) (2.75; 2.21-3.41; p < 0.001) and mosquito coil use (relative to non-use) (1.27; 0.99-1.62; p=0.058) had an impact on the respiratory health of male adults in Hong Kong.

Air Pollution↗
PubMed2004

Suicidality and cultural values among Hong Kong adolescents.

Scholars have proposed that individualistic values resulting from globalization are associated with increasing behavioral and emotional problems among youth in modernizing cultures. This study examined specific individualistic and traditional values in the context of suicidal ideation and behaviors in Hong Kong among community adolescent youths (N=2427) ages 14-18 years. Participants indicated the extent to which self-direction/independence and obedience/respect for elders were important to them. They also reported on four progressive levels of suicidality: whether in the last year they had experienced suicidal ideation, made plans for a suicide attempt, attempted suicide, and (for attemptors) made a serious attempt requiring medical attention. After controlling for quality of family relationships and depressive symptoms, at least one of the values predicted suicidality at all but the highest level. There were sex-specific associations between values and suicidality. In general, endorsement of self-direction was correlated with reduced risk of suicidality for boys and was irrelevant to girls. In contrast, traditional emphases on obedience and respect for elders were more frequently protective against suicidality for girls and were inconsistent predictors for boys. The relationship between values and suicidality was generally independent of the effect of family relationships and depressive symptoms. Thus, values were associated with adolescent suicidality, but not consistently in the direction predicted by some theorists, and the association depended upon the adolescent's sex.

Adolescent↗
PubMed2004

Depressive symptoms among Hong Kong adolescents: relation to atypical sexual feelings and behaviors, gender dissatisfaction, pubertal timing, and family and peer relationships.

A representative community sample of Hong Kong boys (n = 1,024) and girls (n = 1,403), age 14-18 years, provided information regarding same-sex attraction, gender dissatisfaction, pubertal timing, early experience with sexual intercourse, and depressive symptoms. They also rated the quality of their family and peer relationships and self-perceived attractiveness. Depressive symptoms were higher in youths reporting same-sex attraction, gender dissatisfaction, early pubertal maturation, and early sexual intercourse. Family relationships were less satisfactory for those who reported same-sex attraction, gender dissatisfaction, and early sexual intercourse, and peer relationships were also worse for those who reported gender dissatisfaction. In multivariate analyses, same-sex attraction, early sexual intercourse, and early pubertal maturation were unique and direct contributors to depressive symptoms; however, gender dissatisfaction's association with depressive symptoms was largely accounted for by shared correlations with negative family and peer relationships. The multivariate model explained 11% of the variance of depressive symptoms. These findings offer a preliminary documentation of the prevalence and correlates of atypical sexual self-assessments and behavior among adolescents in Hong Kong. Such information is important if theories of sexual identity and risk factors for depressive symptoms are to have cross-cultural utility.

Adolescent↗
PubMed2004

Smoking and depressive symptoms in Chinese elderly in Hong Kong.

OBJECTIVE: To examine the association between smoking and depressive symptoms among Chinese elderly in Hong Kong. METHOD: Cross-sectional data on smoking and depressive symptoms from 56,167 Chinese elderly aged 65 or over in Hong Kong were analysed using logistic regression. RESULTS: Current smokers and former smokers were more likely to have depressive symptoms than never smokers. The adjusted odds ratios (OR) and 95% confidence interval (CI) in males and females respectively were 1.62 (1.34-1.96) and 1.43 (1.20-1.70) for current smokers, and were 1.18 (0.99-1.40) and 1.29 (1.12-1.47) for former smokers. Former smokers were less likely to have depressive symptoms than current smokers (OR = 0.80, 95% CI: 0.70-0.92). CONCLUSION: Smoking is positively associated with depressive symptoms in Chinese elderly. Health care workers should be vigilant about the detection of depressive symptoms in elderly smokers.

Aged↗
PubMed2004

Suicidality among high school students in Hong Kong, SAR.

Suicide is the leading cause of death in Hong Kong SAR for the youth aged 15-24. This study examined the prevalence of suicidality among secondary school students in Hong Kong using a representative, territory-wide sample of 2,586 students. Suicidal behaviors can be conceptualized as a spectrum of self-destructive behaviors. Cumulative logit model analysis indicated that a range of factors, such as unhappy family life, were associated with increasing levels of suicidality. Use of illicit drugs, inhalants, and tobacco differentiated attempters from ideators. The implications of the research findings are discussed.

Adolescent↗
PubMed2004

Blood glucose and risk of cardiovascular disease in the Asia Pacific region.

OBJECTIVE: To assess the shape and strength of the association between usual blood glucose and cardiovascular disease (CVD) in Asian and Australasian cohorts and to determine the impact of adjusting for other determinants of CVD risk and excluding people with diabetes. RESEARCH DESIGN AND METHODS: Relative risk estimates and 95% CIs were calculated from Cox models, stratified by sex and cohort, and adjusted for age at risk on individual participant data from 17 cohort studies. Repeat measurements of blood glucose were used to adjust for regression dilution bias. RESULTS: Fasting blood glucose data were available for 237,468 participants, and during approximately 1.2 million person-years of follow-up, there were 1,661 stroke and 816 ischemic heart disease (IHD) events. Data were also available on 27,996 participants with nonfasting glucose measurements. Continuous positive associations were demonstrated between usual fasting glucose and the risks of CVD down to at least 4.9 mmol/l. Overall, each 1 mmol/l lower usual fasting glucose was associated with a 21% (95% CI 18-24%) lower risk of total stroke and a 23% (19-27%) lower risk of total IHD. The associations were similar in men and women, across age-groups, and in Asian compared with Australasian (Australia and New Zealand) populations. Adjusting for potential confounders or removing those with diabetes as baseline did not substantially affect the associations. Associations for nonfasting glucose were weaker than those with fasting glucose. CONCLUSIONS: Fasting blood glucose is an important determinant of CVD burden, with considerable potential benefit of usual blood glucose lowering down to levels of at least 4.9 mmol/l.

Aged↗
PubMed2003

Diet and glucose tolerance in a Chinese population.

BACKGROUND: Associations between dietary factors and glucose tolerance observed in Caucasian populations may not be applicable to Chinese populations, since the traditional Chinese diet contains plentiful vegetables and is rice-based (which has a lower glycemic index than potatoes). To address this question, the dietary patterns in 988 Hong Kong Chinese subjects with normal and impaired glucose tolerance, and diabetes, were examined in a cross sectional survey to determine if there is any association between diet and glucose tolerance. METHOD: A stratified random population sample of 988 subjects (488 male, 500 female) was recruited. A food frequency questionnaire was used to determine dietary intake, and glucose tolerance was examined using the glucose tolerance test and the WHO criteria used to classify subjects into the three glucose tolerance categories. RESULTS: Using the standardized world population of Segi, the prevalence rate for DM was 6.6% for men and 5.7% for women; and for IGT 10.3% for men and 15.4% for women aged 30-64 y. Abnormal glucose tolerance is associated with female gender, older age, lower educational attainment and higher body mass index (BMI). No clear pattern of association with dietary factors was observed after adjusting for confounding factors. However, if subjects with BMI>or=25 kg/m(2) were excluded, an increase in mean consumption of rice/noodles/pasta per week was observed in the DM group, after adjusting for total energy intake and other confounding factors. No association between dietary variety, which has been linked with body fatness, and glucose tolerance, was observed. CONCLUSION: Dietary habit may not be a strong risk factor for the development of glucose intolerance in Chinese populations, given the favorable features of the Chinese diet. The high consumption of rice in the DM subjects who are of normal BMI suggests that further studies examining glycemic indices of Chinese food items may be beneficial. Obesity still remains the most important predisposing factor.

Adult↗
PubMed2003

SARS: public health measures in Hong Kong.

As there are no validated and rapid diagnostic tests nor specific treatment for severe acute respiratory syndrome (SARS) at the initial stage of the outbreak, public health measures are vital for the control of the disease. These included an enhanced disease surveillance system, expanded laboratory diagnostic capacity, heightened infection control in hospitals and residential institutions for the elderly, intensive contact tracing coupled with medical surveillance at designated medical centres, quarantine of close contacts by way of home confinement, formation of multidisciplinary investigation and response teams, and public education and communication. The above measures were implemented in many countries during the outbreak. To prevent spread in the region and beyond, port health measures targeted at both entry and exit health screenings were also carried out together with regional and international liaison.

Contact Tracing↗