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Biomedical subjects

T H Lam

Publications and source records attributed to T H Lam.

At least 55 records · Page 3Linked to original sources
PubMed2003

C-reactive protein predicts the deterioration of glycemia in chinese subjects with impaired glucose tolerance.

OBJECTIVE: Recent studies have shown that C-reactive protein (CRP) predicts future risk of diabetes in healthy Caucasians. We determined whether plasma CRP level was elevated in Chinese subjects with impaired glucose tolerance (IGT) and whether CRP level could be used to predict progression to type 2 diabetes or reversion to normal glucose tolerance (NGT) in these high-risk individuals. RESEARCH DESIGN AND METHODS: A total of 228 subjects with IGT at baseline from the Hong Kong Cardiovascular Risk Factors Prevalence Study underwent repeat oral glucose tolerance testing after 2 years. Plasma high-sensitivity CRP was measured from their stored baseline samples and from 228 subjects with NGT matched for age and BMI by an immunoturbidimetric assay. RESULTS: Subjects with IGT at baseline had higher plasma CRP levels than subjects with NGT: 1.18 mg/l (0.52-2.52) vs. 0.87 mg/l (0.37-1.84), median (interquartile range), P = 0.01. At 2 years, 117 subjects with IGT reverted to NGT, 84 remained in IGT, and 21 progressed to diabetes. Individuals who progressed to diabetes had the highest plasma CRP levels at baseline (P < 0.0001). Those with baseline CRP levels in the third and top quartile had a relative risk of remaining in IGT or progressing to diabetes of 2.87 (95% CI 1.06-7.82) and 2.76 (1.06-7.31), respectively, after adjusting for anthropometric measure and lifestyle factors. CONCLUSIONS: CRP independently predicts the risk of remaining in IGT or progressing to diabetes in Chinese subjects with IGT. CRP might provide an adjunctive measure for identifying subjects with the highest risk of progression to diabetes who would derive the greatest benefits from preventive interventions.

Adult↗
PubMed2002

Timing of pubertal maturation and heterosexual behavior among Hong Kong Chinese adolescents.

This study presents a cross-sectional examination of the independent contribution of pubertal maturation timing to heterosexual activity among Chinese adolescents. A standardized self-administered questionnaire was designed to obtain information on a spectrum of physical heterosexual behaviors from dating to sexual intercourse, age at first nocturnal ejaculation in boys, age at menarche in girls, and several psychosocial variables that might be associated with sexual behavior in adolescents. A total of 4,116 students aged from 14 to 18 years (2,175 boys and 1,941 girls) were recruited in the Youth Sexuality Survey of the Hong Kong Family Planning Association in 1996-97. When groups were defined as "early," "average," and "late maturers," among boys, early maturers were youngest to report dating and to have sexual intercourse, followed by average and late maturers. Among girls, late maturers were slower to date and have sexual intercourse, but early maturers showed no difference from average maturers. Age of maturation was significantly lower for those reporting all heterosexual behaviors for both sexes. Our findings illustrate culture's moderation of the expression of biological differences.

Adolescent↗
PubMed2002

Smoking and mortality in 81,344 drivers in Guangzhou, China.

OBJECTIVES: Previous studies on drivers focused on the effect of their exposure to vehicle exhaust and there is little evidence of the effect of smoking. This cohort analytical study aimed to examine the mortality of drivers relative to smoking and professional driving in Guangzhou, China. METHODS: Information on demographic characteristics, type of driver (professional and non-professional), smoking, and drinking were retrieved from medical records of drivers who applied for driving licences from March to December 1992. Vital status and causes of death of 81,344 men aged 30 or above were ascertained to the end of September 1999 (follow up, mean=7.14 years, median=7.17 years). RESULTS: At baseline, the mean (SD) age was 40.8 (5.6) years. One third were professional drivers; 49.0% were daily smokers. 858 Deaths were identified. The relative risk of overall mortality for ever smoking was 1.24 (95% confidence interval (95% CI) 1.07 to 1.44) after adjusting for age, alcohol drinking, education, and type of drivers. Compared with non-professional drivers, professional drivers had similar risks of death, and their relative risk of overall mortality for ever smoking was 1.35 (1.06 to 1.71). CONCLUSIONS: Smoking is a more important cause of death than professional driving itself. The results show serious public health problems in the early stage of the tobacco epidemic and support urgent measures to help drivers stop smoking.

Adult↗
PubMed2002

Public opinion on smoke-free policies in restaurants and predicted effect on patronage in Hong Kong.

BACKGROUND: The Hong Kong government has proposed legislation for smoke-free policies in all restaurants and bars. This is opposed by certain sections of the catering industry. OBJECTIVE: To assess public opinion on smoke-free restaurants and to estimate changes in patronage. DESIGN: A population based, cross sectional random digit dialling telephone survey conducted from November 1999 to January 2000. SETTING AND PARTICIPANTS: 1077 randomly selected subjects age 15 years or over (response fraction of 81.6%). RESULTS: 68.9% (95% confidence interval (CI) 66.2% to 71.7%) supported a totally smoke-free policy in restaurants. Experiences of discomfort or symptoms from second hand smoke in restaurants were common. The majority (77.2%, 95% CI 74.7% to 79.7%) anticipated no change in their frequency of use of restaurants after a smoke-free policy. Increased use was predicted by 19.7% (95% CI 17.3% to 22.1%) of respondents, whereas 3.2% (95% CI 2.2% to 4.4%) stated that they would dine out less often. In multivariate analyses, non-smokers (adjusted odds ratio (OR) 4.9), people who ate three times or less per week in restaurants as compared to those who ate >10 times per week (OR 2.1), those who had previous experience of discomfort from exposure to passive smoking in restaurants (OR 2.8), or who had avoided restaurants in the past because of smoking (OR 1.9), were more likely to support a totally smoke-free policy in restaurants. Smoke-free policies do not appear to have an adverse effect on restaurants, and may increase business by a considerable margin. CONCLUSION: This comprehensive survey-the first in Asia-shows strong community support for smoke-free dining and predicts an overall increase in the patronage of restaurants after the introduction of legislation for totally smoke-free restaurants.

Adolescent↗
PubMed2001

Subjective health measure used on Chinese patients with neck pain in Hong Kong.

STUDY DESIGN: A prospective observational study was conducted on the use of the Chinese version of the Northwick Park Neck Pain Questionnaire. OBJECTIVE: To examine the reliability, validity, and responsiveness of the Chinese version of the Northwick Park Neck Pain Questionnaire in Chinese patients with neck pain in Hong Kong. SUMMARY OF BACKGROUND DATA: There is increasing recognition that patient perspectives are essential both in making medical decisions and in judging the treatment outcomes. A valid Chinese version of a neck disability index questionnaire is urgently needed for effective and reliable evaluation of the treatment outcomes for patients with neck pain. METHODS: Two samples with 532 consecutive adult patients with neck pain from seven physiotherapy outpatient departments in Hong Kong who completed the Northwick Park Neck Pain Questionnaire were observed and measured at different intervals: at the beginning of physiotherapy, at 7 days, at 3 weeks, and 6 weeks after physiotherapy. RESULTS: The questionnaire had good content validity, very good test-retest reliability, and internal consistency (intraclass correlation coefficient, 0.95; Cronbach's alpha, 0.87). It also had good validity (Spearman correlation coefficient of 0.59 when the score was correlated with that of a generic 42-item Chinese health questionnaire) and good responsiveness (effect size of 1.11 at week 6 after treatment began). CONCLUSIONS: The Chinese version of the Northwick Park Neck Pain Questionnaire has been shown to demonstrate very good content validity, a high degree of test-retest reliability, and internal consistency. It also exhibited good construct validity and high sensitivity to changes in severity over time.

Adolescent↗
PubMed2001

Mortality and smoking in Hong Kong: case-control study of all adult deaths in 1998.

OBJECTIVE: To assess the mortality currently associated with smoking in Hong Kong, and, since cigarette consumption reached its peak 20 years earlier in Hong Kong than in mainland China, to predict mortality in China 20 years hence. DESIGN: Case-control study. Past smoking habits of all Chinese adults in Hong Kong who died in 1998 (cases) were sought from those registering the death. SETTING: All the death registries in Hong Kong. PARTICIPANTS: 27 507 dead cases (81% of all registered deaths) and 13 054 live controls aged >/=35 years. MAIN OUTCOME MEASURES: Mortality from all causes and from specific causes. RESULTS: In men aged 35-69 the adjusted risk ratios (and 95% confidence intervals) comparing smokers with non-smokers were 1.92 (1.70 to 2.16) for all deaths, 2.22 (1.94 to 2.55) for neoplastic deaths, 2.60 (2.10 to 3.21) for respiratory deaths (including tuberculosis, risk ratio 2.54), and 1.68 (1.43 to 1.97) for vascular deaths (each P<0.0001). In women aged 35-69 the corresponding risk ratios were 1.62 (1.40 to 1.88) for all deaths, 1.60 (1.33 to 1.93) for neoplastic deaths, 3.13 (2.21 to 4.44) for respiratory deaths, and 1.55 (1.20 to 1.99) for vascular deaths (each P<0.001). If these associations with smoking are largely or wholly causal then, among all registered deaths at ages 35-69 in 1998, tobacco caused about 33% (2534/7588) of all male deaths and 5% (169/3341) of all female deaths (hence 25% of all deaths at these ages). At older ages tobacco seemed to be the cause of 15% (3017/20 420) of all deaths. CONCLUSIONS: Among middle aged men the proportion of deaths caused by smoking is more than twice as big in Hong Kong now (33%) as in mainland China 10 years earlier. This supports predictions of a large increase in tobacco attributable mortality in China as a whole.

Adult↗
PubMed2001

Lymphocyte DNA damage in bus manufacturing workers.

To study the effect of occupational exposure, smoking, and drinking on lymphocyte DNA damage in bus manufacturing workers, 346 employees (106 women and 240 men) from six job categories (welders, mechanics, painters, and assembling, auxiliary and managerial workers) in a bus manufacturing factory in Guangzhou were included. Significant differences of tail moment among the six job categories were found (P=0.003) with adjustment for age and gender. Smoking increased tail moment significantly (3.14 (2.89-3.40) versus 2.79 microm (2.63-2.97), P=0.023). Analysis of covariance showed that occupational exposure (P=0.001) and smoking (P=0.019) had significant effect on tail moment after adjusting for all factors, whereas age and gender had no effect on DNA damage. Stratified analysis showed that painters (P=0.002), auxiliary workers (P=0.011), and mechanics (P=0.044) had larger tail moments than managerial workers after adjusting for age, gender, smoking, and drinking.

Comet Assay↗
PubMed2001

Accelerated silicosis in workers exposed to agate dust in Guangzhou, China.

BACKGROUND: An investigation of a small private agate mill was prompted by an agate worker who presented with silicosis in Guangzhou, China, in December 1998. METHODS: The work processes and records of dust measurements of the mill were examined. The mean total dust concentrations ranged from 3.0 to 9.9 mg/m3; 86-88% of the particles' diameter was smaller than 5.0 microm. Free SiO2 content from agate samples was measured. Occupational history was obtained and X-ray chest and lung function was carried out. RESULTS: Free SiO2 content of the agate was 90.5%. Thirty-two men involved in processing agate stone were examined. The mean ( +/- SD) age was 29.8 ( +/- 4.9) years and the mean (+/- SD) duration of exposure was 3.5 (+/- 1.7) years. Fifteen cases (47%) were diagnosed as accelerated silicosis. Up to September 1999, three had died from respiratory failure and five were in critical condition. CONCLUSIONS: Silicosis is an important problem in primitive work environments.

Adult↗
PubMed2001

Sodium is the leading dietary factor associated with urinary calcium excretion in Hong Kong Chinese adults.

We conducted a cross-sectional population-based study comprising 1010 Hong Kong Chinese (500 men and 510 women) aged 25-74 years during 1995-6. The study examined the important dietary, lifestyle and anthropometric factors associated with urinary calcium excretion. Dietary intakes were assessed by means of food frequency questionnaire. Spot urine was collected to measure the urinary excretion profiles of calcium (Ca), sodium (Na), potassium (K) and creatinine (Cr). When expressed as ratios of cations to urinary Cr, significant relationships were noted between urinary Ca and Na (r: approximately 0.6), and between urinary Ca and K (r: 0.17-0.21). Stepwise multiple linear regression analyses were carried out separately in men and women aged below and above 50 years. We found that urinary Na/Cr was the leading independent factor associated with urinary Ca/Cr in all four age and sex groups. It accounted for 22% of urinary Ca/Cr variations in women aged below 50 years, and 35-43% in the other three age and sex groups. We estimated that urinary Ca excretion increased by about 1.4 (range 1.37-1.43) mmol per 100 mmol increase in urinary Na. Except in men aged 50 years and over, urinary K/Cr was inversely associated with urinary Ca/Cr in all groups. Age was independently and positively associated with urinary Ca/ Cr in subjects aged below 50 years. We did not observe any significant relation between urinary Ca/Cr and dietary protein, phosphorus, alcohol drinking and smoking. In conclusion, we found that urinary Na/Cr, but not dietary protein, Ca or phosphorus, is the most important factor influencing urinary Ca/Cr excretion in our population. Urinary K is a potential factor for Ca conservation.

Adult↗
PubMed2001

Prevalence and correlates of smoking and sexual activity among Hong Kong adolescents.

PURPOSE: To report on the prevalence and correlates of smoking and sexual activity in a community sample of Hong Kong Chinese adolescents. METHODS: Participants (N = 4116) aged 13 to 18 years were surveyed regarding smoking and physical heterosexual activity, relationships with family members, family involvement, social support, school performance and emotional adjustment. Data were analyzed using logistic regression analyses. RESULTS: About 30% of participants reported ever smoking and 3.5% reported sexual intercourse. Current smoking was correlated with age, school performance and quality of relationship with mother. Sexual intercourse was correlated with age, gender, family involvement and social support. Smoking and sexual activity were significantly correlated with each other. Smoking and increasing levels of heterosexual physical contact were negatively correlated with emotional adjustment, even after controlling for common predictors to health-endangering behaviors and emotional adjustment. CONCLUSIONS: Smoking and sexual activity among adolescents are far less common in Hong Kong than in the West and their presence in a Hong Kong adolescent should alert the health practitioner to the possibility of significant psychosocial stress and maladjustment.

Adolescent↗
PubMed2001

Smoking and high-risk sexual behavior among young adults in Hong Kong.

Young adults (n = 964; never married; age, 18-27 years) in Hong Kong were surveyed to obtain information about their smoking habits and sexual behaviors. Current smokers (15% of the entire sample) and those who had ever had sexual intercourse (28%) were more likely to be male, to have ended their education at secondary school, and to report less life satisfaction. After controlling for demographic and psychosocial correlates, sexual intercourse was associated with smoking status for both males and females. Among those who were sexually active, those who had multiple sexual partners, had their first sexual experience prior to age 18 years, and (for males) reported visiting massage parlors were more likely to have a history of smoking. Our findings extend those of our previous study with community adolescents in Hong Kong and suggest that smoking may be a marker for other high-risk behaviors among young Chinese adults.

Adolescent↗
PubMed2001

Association between simple anthropometric indices and cardiovascular risk factors.

OBJECTIVE: To identify which of the three simple anthropometric indices, body mass index (BMI), waist-to-hip ratio (WHR) and waist circumference (WC), best predicts cardiovascular risk factors, and to determine if the association between the anthropometric indices and cardiovascular risk factors varies with gender. DESIGN AND METHODOLOGY: A cross-sectional population-based survey was carried out during 1995-1996. One thousand and ten Chinese people (500 men and 510 women) aged 25-74 y were recruited as subjects for the study. Metabolic profiles and anthropometric indices were measured. RESULTS: Partial correlation and co-variance analyses showed that WC exhibited the highest degree of association with almost all of the studied metabolic profiles for both men and women. We observed significant gender differences in the association between central or general obesity with cardiovascular risk factors. BMI had an independent and significant association with metabolic risks in men, but not in women, whereas WHR was more strongly correlated with metabolic risks for women than for men. Logistic regression analysis further confirmed the magnitude of the association between the obesity indices and metabolic risks. Among the studied metabolic variables, serum insulin showed the highest degree of association with the obesity indices, followed by plasma glucose, triglyceride, HDL and blood pressure. Total cholesterol and LDL-cholesterol had a small but significant correlation with obesity. No threshold values in the relation between either the anthropometric indices and metabolic values, or with hypertension, diabetes and dislipidemia were observed. CONCLUSION: The association of central or general obesity and metabolic syndrome varied with gender. In addition, the useful anthropometric predictors for cardiovascular risk factors were BMI and WC for men, and WC and WHR for women.

Abdomen↗
PubMed2001

Central obesity predicts the worsening of glycemia in southern Chinese.

AIMS: The association between obesity and type 2 diabetes has been found to be consistent across different ethnic populations. Our aim was to study the contribution of obesity to the development of type 2 diabetes in a non-obese Chinese population with a high prevalence of diabetes (9.8% in 1995-1996). METHODS: Six-hundred and forty-four non-diabetic subjects were recruited from the Hong Kong Cardiovascular Risk Factor Prevalence Study (1995-1996). This was a community-based population study which involved the use of a 75 g oral glucose tolerance test and 1985 World Health Organization diagnostic criteria. Their glycemic status was reassessed at 2 y. RESULTS: In subjects with impaired glucose tolerance (n=322), the annual progression rate to diabetes (4.8%; 95% CI 2.5-7.1%), was 8-fold that in control subjects (0.6%; 95% CI 0.0-1.4%; P<0.001). Baseline waist-hip ratio (WHR; OR per unit increase=1.05; 95% CI 1.02-1.07, P=0.0003) and post-load 2 h plasma glucose (OR per unit increase=2.02; 95% CI 1.76-2.34, P<0.0001) were significantly associated with glycemic status at 2 y in stepwise polytomous logistic regression analysis. Subjects with high baseline waist circumference or WHR (> or =median) were more likely to have worsening of glucose tolerance at 2 y than those with low waist circumference (<median; conversion to diabetes, OR 3.8, P=0.001) or WHR (<median; conversion to diabetes, OR 2.8, P=0.019). CONCLUSION: Abdominal obesity, readily assessed by the measurement of WHR or waist circumference, was for the first time shown prospectively to be independently associated with the deterioration of glucose tolerance in a Chinese population.

Abdomen↗
PubMed2001

Rates of cesarean births in Hong Kong: 1987-1999.

BACKGROUND: High cesarean birth rates are an issue of international public health concern. The purpose of this paper was to examine the annual incidence and secular trend of cesarean births in Hong Kong and to correlate these rates with socioeconomic, demographic, and health indicators for the population since 1987. METHODS: This was a descriptive and ecologic study. Annual population rates of cesarean sections were estimated for 1987 from a population-based survey, and for 1993 through 1999 from government data sources. The number of excess cesarean sections was calculated for each year using the 15 percent upper limit as proposed by the World Health Organization. RESULTS: From 1987 to 1999 the overall annual cesarean section rate rose steadily from 16.6 to 27.4 per 100 hospital deliveries, resulting in a 65 percent increase over 12 years. The mean difference in rates of surgical delivery between public (mean(public) = 16.0%) and private (mean(private) = 43.4%) institutions was 27.4 percent (95% confidence interval (CI) = 24.1, 30.7; p < 0.001). CONCLUSIONS: This is the first systematic report of secular variations of cesarean delivery rates in Asia. The high rates and increasing trend represent an unnecessary excess risk for mothers and their infants. Various strategies combating high cesarean rates have been proposed and have succeeded elsewhere. Concerted action from health care professionals, public health authorities, the general population, and the media is urgently required to implement solutions to reduce the rate of cesarean delivery.

Adult↗
PubMed2001

Effect of air pollution on daily mortality in Hong Kong.

In different weather conditions, constituents and concentrations of pollutants, personal exposure, and biologic responses to air pollution may vary. In this study we assessed the effects of four air pollutants on mortality in both cool and warm seasons in Hong Kong, a subtropical city. Daily counts of mortality, due to all nonaccidental causes, and cardiovascular and respiratory diseases were modeled with daily pollutant concentrations [24-hr means for nitrogen dioxide, sulfur dioxide, and particulate matter < 10 microm in aerodynamic diameter (PM(10)); 8-hr mean for ozone]. using Poisson regression. We controlled for confounding factors by fitting the terms in models, in line with those recommended by the APHEA (Air Pollution and Health: a European Approach) protocol. Exposure-response relationships in warm and cool seasons were examined using generalized additive modeling. During the cool season, for a linear extrapolation of 10th-90th percentiles in the pollutant concentrations of all oxidant pollutants, NO(2), SO(2), and O(3), we found significant effects on all the mortality outcomes under study, with relative risks (RR) of 1.04-1.10 (p < 0.038, except p = 0.079 for SO(2) on respiratory mortality). We observed consistent positive exposure-response relationships during the cool season but not during the warm season. The effects of PM(10) were marginally significant (RR = 1.06; p = 0.054) for respiratory mortality but not for the other outcomes (p > 0.135). In this subtropical city, local air quality objectives should take into account that air pollution has stronger health effects during the cool rather than warm season and that oxidant pollutants are more important indicators of health effects than particulates.

Adolescent↗