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Biomedical subjects

T H Lam

Publications and source records attributed to T H Lam.

At least 73 records · Page 4Linked to original sources
PubMed2001

The effects of environmental tobacco smoke on health services utilization in the first eighteen months of life.

OBJECTIVE: To examine the effects of environmental tobacco smoke (ETS) on health services use in Chinese infants with nonsmoking mothers. DESIGN: Prospective, population-based birth cohort. SETTING: General population of Hong Kong in 1997-1998. PARTICIPANTS: A total of 8327 parent-infant pairs who were followed up for 18 months. MAIN OUTCOME MEASURES: Doctor consultations and hospitalizations. Results. After adjusting for the age, education level, and employment status of mothers-as well as infants' birth weight, method of delivery, breastfeeding status, and birth order-ETS exposure through the mother in utero was positively associated with higher consultation (adjusted odds ratio [OR]: 1.26; 95% confidence interval [CI]: 1.14, 1.39) and hospitalization (OR: 1.18; 95% CI: 1.05, 1.31) use in infants with nonsmoking mothers attributable to any illness. In addition, postnatal exposure to ETS at home was linked to higher rates of hospitalizations for any illness compared with nonexposed infants (OR: 1.12; 95% CI: 1.00, 1.25), although the relationship did not hold for outpatient consultation visits. The OR for higher hospital use in infants exposed to 2 or more smokers at home was 1.30 (95% CI: 1.08, 1.58). CONCLUSIONS: The use of tobacco products by household members, even among nonsmoking mothers, has an enormous adverse impact on the health of children, as well as increases health services use and cost. The present data support the revision of public policy to reflect an evidence-based approach to the promotion of smoking cessation in all household members during and after pregnancy. environmental tobacco smoke, health services, infants.

Adult↗
PubMed2001

Dietary habit of smokers in a Chinese population.

The objective of this study is to determine whether smokers have unhealthy dietary habits with respect to cardiovascular diseases and cancer. An age and sex stratified random sample of the Hong Kong Chinese population aged 25 to 74 years (500 men, 510 women) was recruited. A dietary assessment using a food frequency method over a 7 day period, together with a lifestyle questionnaire was administered by a trained interviewer. Approximately half the men were smokers, while only 19/510 women smoked. Smoking was related to lower education level. Male smokers had a lower mean daily consumption of fruits, lower carbohydrate and carbohydrate percentage calorie intake, higher fat and fat percentage calorie intake, and higher vitamin D intake compared with non-smokers. However, the differences were small compared with reported differences in Caucasian populations. No difference in dietary pattern was noted between female smokers and non-smokers. Although there is a tendency for male smokers to have an unhealthy dietary pattern with respect to cardiovascular disease and cancer, the differences between smokers and non-smokers are small, and together with the favourable health features of the Chinese diet, this difference is unlikely to add to the risk of these diseases in smokers or be a confounding factor in examining the aetiology of smoke-related diseases in this population.

Adult↗
PubMed2001

Universal antenatal human immunodeficiency virus testing in Hong Kong: consensus statement.

Following the recommendations of the Advisory Council on AIDS, Hong Kong, the Hospital Authority announced plans to introduce universal antenatal screening for human immunodeficiency virus infection and hence, a consensus conference was held to discuss strategies for implementing such screening in Hong Kong. This paper reports the discussions of the consensus conference. The consensus meeting group consisted of 15 clinicians and scientists from Hong Kong, Macau, and Thailand. Seven commonly asked questions concerning mother-to-child transmission of human immunodeficiency virus were selected for discussion by the participating panellists. Information on the laboratory diagnosis of human immunodeficiency virus infection and the efficacy of preventive measures in reducing mother-to-child transmission of human immunodeficiency virus were reviewed. Data from local studies was also presented and discussed. The timing, potential problems, and cost issues involved in testing all pregnant women in Hong Kong for human immunodeficiency virus were then considered.

Adult↗
PubMed2000

Increased lymphocyte DNA strand breaks in rubber workers.

OBJECTIVE: To study the effect of occupational exposure to rubber processing, smoking, and alcohol drinking on lymphocyte DNA damage. SUBJECTS AND METHODS: Of 371 employees (197 men and 174 women) from a rubber factory in Guangzhou, 281 were rubber processing workers from five production sections and 90 were managerial workers. Information on occupational exposure, smoking, and drinking was collected by interviews. Blood samples were taken in the morning by venipuncture. DNA damages were measured by the Comet assay. Possible DNA-protein crosslinks were broken down by proteinase K. Tail moment, measured by Komet 4.0 image analysis software, was the measure of DNA damage. RESULTS: The rubber processing workers had larger tail moment than the managerial workers (Geometric mean, 95%CI) [1. 77microm (1.64-1.90) versus 1.52microm (1.36-1.71), P=0.04]. Both smoking [1.93microm (1.74-2.13) versus 1.59microm (1.47-1.71), P=0. 003] and alcohol drinking [2.21microm (1.87-2.62) versus 1.63microm (1.53-1.74), P<0.001] increased tail moment. Tail moment differed significantly among job categories (F=3.21, P=0.008), the largest was observed in mixers. In the non-smoking and non-drinking workers, rubber processing workers had larger tail moment than managerial workers after adjusting for age (P=0.033). General linear model analysis showed that after adjusting for each other, occupational exposure (P=0.027), smoking (P=0.012), and alcohol drinking (P=0. 013) was associated with larger tail moment, whereas age and gender had no effect. CONCLUSIONS: Occupational exposure to rubber processing, smoking, and alcohol drinking can cause DNA damage.

Comet Assay↗
PubMed2000

Environmental tobacco smoke exposure among police officers in Hong Kong.

CONTEXT: Few epidemiological studies have examined the relationship between chronic respiratory symptoms and exposure to environmental tobacco smoke (ETS) at work in adults, and none have shown clear dose-response relationships. OBJECTIVE: To examine the respiratory effects of ETS exposure at home and at work among never-smoking adults. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional, self-administered questionnaire survey conducted in December 1995 and January 1996 among 4468 male and 728 female police officers in Hong Kong who were never-smokers. MAIN OUTCOME MEASURES: Respiratory symptoms and physician consultation in the previous 14 days for such symptoms by presence and amount of ETS exposure at work. RESULTS: Eighty percent of both men and women reported ETS exposure at work. Significant odds ratios (ORs) for respiratory symptoms were found among men with ETS exposure at work (for any respiratory symptoms, difference in absolute rate, 20.4%; OR, 2.33; 95% confidence interval [CI], 1.97-2.75; attributable risk, 57%) and physician consultation (difference in absolute rate, 4.5%; OR, 1.30; 95% CI, 1. 05-1.61; attributable risk, 23%). Trends were similar among women for any respiratory symptoms (difference in absolute rate, 15.4%; OR, 1.63; 95% CI, 1.04-2.56; attributable risk, 39%) and for physician consultation (difference in absolute rates, 2.8%; OR, 1.45; 95% CI, 0.87-2.41; attributable risk, 31%). Positive dose-response relationships with number of coworkers smoking nearby and amount of ETS exposure in the work place were found. CONCLUSIONS: This study provides further evidence of the serious health hazards associated with ETS exposure at work. The findings support a ban on smoking in the workplace to protect all workers in both developed and developing countries. JAMA. 2000;284:756-763

Adult↗
PubMed2000

Fibrinogen, angina and coronary heart disease in a Chinese population.

Although fibrinogen is an established risk factor of coronary heart disease (CHD), whether fibrinogen is associated with CHD in Chinese is not clear. This population-based cross-sectional study aimed to analyse this relationship in Hong Kong Chinese. Fibrinogen was measured by the Clauss method in 1348 men and 1385 women aged 25-74 years. Severity of CHD was defined as most serious if the subjects had medically diagnosed CHD, as less serious if they had angina only, and as normal if they had neither. The prevalence of angina and CHD was respectively 2.4% and 2.2% in men and 3.2% and 2.7% in women. In men the age-adjusted mean fibrinogen concentration was 2.47 (95% confidence interval (CI) 2.43-2.51) g/l in the normal group, 2.65 (95% CI 2.45-2.85) g/l in the angina group, and 2.78 (95% CI 2.56-3. 00) g/l in the CHD cases (P<0.01); in women it was respectively 2.61 (95% CI 2.59-2.63), 2.66 (95% CI 2.50-2.82), 2.90 (95% CI 2.72-3.08) g/l (P<0.01). The differences were significant after adjustment of other significant risk factors. We conclude that fibrinogen should be considered as a risk factor in Chinese.

Adult↗
PubMed2000

The prevalence of diabetes, association with cardiovascular risk factors and implications of diagnostic criteria (ADA 1997 and WHO 1998) in a 1996 community-based population study in Hong Kong Chinese. Hong Kong Cardiovascular Risk Factor Steering Committee. American Diabetes Association.

AIMS: While the American Diabetes Association (ADA) 1997 diagnostic criteria advocate the use of fasting plasma glucose only, the World Health Organization (WHO) criteria retain the use of the standard oral glucose tolerance test (OGTT). The present study evaluated the relative merit of the respective diagnostic criteria in Chinese. METHODS: Data collected for the Hong Kong Cardiovascular Risk Factor Prevalence Study was analysed. This was a representative population-based study, conducted from 1995 to 1996 among 2,900 Chinese subjects aged 25-74 years using a 75-g OGTT. RESULTS: The prevalence of diabetes (known plus unknown) was 6.2% (95% confidence interval 5.3-7.1%), 9.2% (8.1-10.3%), and 9.8% (8.7-10.9%) based on ADA 1997, WHO 1985 and WHO 1998 criteria, respectively, with a very high prevalence in older subjects. The 2,451 subjects classified as normal under ADA 1997 criteria were heterogenous: 15.3% had impaired glucose tolerance; 2.1% had diabetes under WHO 1998 criteria. These latter two smaller groups had cardiovascular risk profiles comparable to that found among the impaired fasting glucose subjects (under ADA), but worse than that among the concordant normal glucose tolerance subjects. CONCLUSIONS: The ADA criteria underestimate both diabetes prevalence and cardiovascular risk in this population. Hence fasting glucose alone is an inadequate approach and OGTT should be retained to identify at-risk individuals in both clinical diagnosis and epidemiological studies.

Adult↗
PubMed2000

Fibrinogen, other cardiovascular risk factors and diabetes mellitus in Hong Kong: a community with high prevalence of Type 2 diabetes mellitus and impaired glucose tolerance.

AIMS: To determine the prevalence of Type 2 diabetes mellitus and impaired glucose tolerance (IGT) and their relationships to fibrinogen and other cardiovascular risk factors in Hong Kong Chinese. METHODS: A probability sample of 1,316 men and 1,348 women aged 25-74 years were examined in a population-based cross-sectional study. RESULTS: A total of 3.0% (95% confidence interval 2.1-3.9) of men had previously diagnosed (known) and 6.4% (5.0-7.8) newly diagnosed (unknown) diabetes, 14.4% (12.4-16.5) had IGT and 79.2% were normal by 1985 WHO diagnostic criteria; corresponding prevalences in women were 3.7% (2.7-4.7), 5.9% (4.6-7.2), 17% (14.8-19.2) and 73.4%. The age-standardized prevalence of Type 2 diabetes for the 35-64 age group was 9.5% (7.5-11.6) in men and 10.2% (8.0-12.4) in women. Age-adjusted mean fibrinogen levels in these four groups (normal/IGT/unknown diabetes/known diabetes) with decreasing degrees of glucose tolerance (diabetes status) were 2.80, 2.57, 2.51 and 2.47 g/l (P = 0.003) in men, and 2.86, 2.72, 2.67, 2.61 g/l (P = 0.005) in women. Age, obesity, systolic blood pressure and triglycerides were significantly associated with diabetes status in both sexes, fibrinogen in men only and high density lipoprotein cholesterol negatively in women. CONCLUSIONS: The prevalence of Type 2 diabetes mellitus was very high especially in older subjects, and fibrinogen was associated with increasing glucose intolerance in men but not in women. The detection and better control of cardiovascular risk factors, particularly hypertension in this developed Chinese community with a high prevalence of diabetes and glucose intolerance, is particularly important.

Adult↗
PubMed2000

Intake of soy products is associated with better plasma lipid profiles in the Hong Kong Chinese population.

We describe the pattern of soy intake and its association with blood lipid concentrations in the Hong Kong Chinese population. Subjects were contacted by random telephone survey and invited to a hospital for a physical examination and blood tests. A total of 500 men and 510 women with an age range of 24-74 y completed the dietary intake study. The dietary assessment was based on a semiquantitative food frequency questionnaire that included 10 commonly consumed soy items. Many (88%) of the study population had consumed some soy products during the previous week. About 80% of the soy protein or isoflavones were obtained from different forms of tofu, and an additional 9% was obtained from soy milk. The mean weekly isoflavone intake was 102 +/- 107 mg in men and 77 +/- 90 mg in women. In men, soy intake and total plasma cholesterol were negatively correlated (r = -0.09, P: = 0.04), as were soy intake and LDL cholesterol (r = -0.11, P: = 0.02). The respective values in women <50 y old were r = -0.11, P: = 0.04 and r = -0.11, P: = 0.05. Soy protein remained significantly associated with these two lipid concentrations after adjustment for other social and dietary confounders. Higher soy intake seemed to be related to a better plasma lipid profile in men and in younger women, but more epidemiological studies and controlled clinical trials in this setting would help to confirm the optimal amount required for the prevention and treatment of hyperlipidemia.

Adult↗
PubMed2000

Passive smoking at work: the short-term cost.

STUDY OBJECTIVE: To estimate the impact of passive smoking at work on use of health care services and absenteeism. DESIGN: Cross sectional survey. SETTING: A workforce in Hong Kong. PARTICIPANTS: 5142 never-smoking police officers in a total sample of 9926. MAIN RESULTS: A consistently strong association was found among men between length of time exposed to passive smoking at work and self reported consultations with a doctor, use of medicines and time off work. Results for women were similar but most were not statistically significant. CONCLUSIONS: The exposure of healthy adults to passive smoking at work is related to utilisation of health care services and extra time off work. This results in costs to the health services, to employers and to those exposed.

Absenteeism↗
PubMed2000

Exposure to and actions against passive smoking in non-smoking pregnant women in Guangzhou, China.

BACKGROUND: The objective was to describe the extent of passive smoking exposure and preventive actions against passive smoking in non-smoking pregnant women and to analyze factors associated with preventive actions. METHODS: This was a cross-sectional survey on 1449 never-smoking pregnant women who made their first prenatal visit to the Women and Children's Hospital of Guangzhou, China during 1996-97. RESULTS: 60.2% (95% Confidence Interval 57.7%-62.7%) of the never-smoking pregnant women had a husband who currently smoked. Women with smoking husbands (n=872) were more exposed to ETS than those with non-smoking husbands (n=577) at home (71% vs. 33%), in public places (77% vs. 66%) and at work (60% vs. 50% of working women), and they took less actions against passive smoking in public places. Women with better education and knowledge on smoking and passive smoking had stronger preventive actions. CONCLUSIONS: Non-smoking pregnant women in China are often exposed to passive smoking and their preventive actions are weak. Passive smoking is an important obstetric and public health problem in developing countries and deserves urgent international attention.

Adult↗
PubMed1999

Lymphocyte DNA damage in cigarette factory workers measured by the Comet assay.

To investigate whether there were separate and combined effects of occupational exposure to tobacco dust and smoking on lymphocyte DNA damage, 148 workers from a cigarette manufacturing factory (107 occupationally exposed to tobacco dust from the production department and 41 unexposed controls who were managerial workers) were included in the study. The Tail Moment (TM) of Comet assay was used to measure DNA damage. The two groups had similar mean age, mean duration of work and smoking prevalence. The exposed workers had a larger TM than that of the controls (mean+/-S.D.: 43.43+/-13. 77 vs. 38.89+/-8.98, p<0.05). Smokers had significantly larger TM than non-smokers (47.25+/-14.02 vs. 38.90+/-10.75, p<0.001). Analysis of variance after adjustment for age and gender showed that occupational exposure and smoking had a significant and independent effect on Tail Moment (p=0.025 and p=0.002, respectively) and there was a significant positive two way interaction between the two factors (p=0.019). Age and gender had no significant effect on TM. The present study suggests that smoking and tobacco dust exposure can induce lymphocyte DNA damage and there is a synergistic effect of tobacco dust exposure and smoking on DNA damage.

Adult↗
PubMed1999

Use of a subjective health measure on Chinese low back pain patients in Hong Kong.

STUDY DESIGN: A prospective observational study on the use of the Aberdeen Low Back Pain Disability Scale. OBJECTIVE: To evaluate the reliability, validity, and responsiveness of the Chinese adaptation of the Aberdeen Low Back Pain Scale in Chinese patients in Hong Kong who have back pain. SUMMARY OF BACKGROUND DATA: Frontline clinicians, researchers, and health care managers in Hong Kong are urgently in need of a Chinese adaptation of a low back pain outcome measure that has been subjected to a rigorous process of psychometric and clinical testing. METHODS: Four samples with 473 consecutive adult patients with low back pain from six physiotherapy outpatient departments in Hong Kong who completed the Aberdeen Low Back Pain Scale were observed and measured at time points including the beginning physiotherapy; 10 days, 3 weeks, and 6 weeks after physiotherapy; and when discharged from treatment. RESULTS: The test-retest reliability coefficient was 0.94 (0.94 in the original English version; figures from the English version are reported in parentheses). The Cronbach alpha coefficient was 0.85 (0.80). The Spearman correlation coefficient, when the Aberdeen score was correlated with that of a generic current 42-item questionnaire regarding the patient's perceived health to establish cross-sectional construct validity, was 0.59 (0.36-0.66, with the Short Form 36 scale). The effect sizes (responsiveness) at weeks 3 and 6 after treatment began were 0.59 and 0.81, respectively (a high of 0.62 reported in the English version). CONCLUSIONS: The Chinese version of the Aberdeen Low Back Pain Disability Scale retained the high levels of reliability, validity, and responsiveness of the original English version when tested in Hong Kong in four samples of Chinese patients with low back pain.

Adolescent↗