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Biomedical subjects

S C Emmanuel

Publications and source records attributed to S C Emmanuel.

At least 19 recordsLinked to original sources
PubMed2001

Diabetes mellitus abolishes ethnic differences in cardiovascular risk factors: lessons from a multi-ethnic population.

AIMS: To compare cardiovascular risk factors in diabetic subjects of different ethnic groups, and between new and known diabetic subjects, in the Singapore National Health Survey '92. METHODS: Disproportionate stratified sampling followed by systematic sampling were used in 3568 (total) respondents of whom 2743 were non-diabetics, 179 newly diagnosed diabetics and 150 known diabetics. Amongst the diabetics, there were 185 Chinese, 66 Malays and 78 Asian Indians. Diagnosis of diabetes mellitus (DM) was based on the 2 h glucose alone, after a 75 g oral glucose tolerance test. Blood pressure (BP), lipid profile, glucose, insulin and anthropometric indices were obtained from all subjects. RESULTS: Subjects with diabetes (new and known) exhibited significantly higher triglyceride (TG), lower high density lipoprotein cholesterol (HDL-C) and low density lipoprotein (LDL)/apolipoprotein B (apo B) ratio (LDL size) compared with normoglycaemic subjects. They were more obese (generalised and central) and had higher systolic and diastolic BP. There was no difference in lipid risk factors between the two groups with diabetes although those with new diabetes were more obese whilst those with known diabetes had higher fasting glucose. Amongst subjects with diabetes, there were no significant differences between ethnic groups in TG, HDL-C, LDL/apo B ratio, or waist to hip ratio (WHR). Female Malays with diabetes had higher total cholesterol and were more obese whilst male Asian Indians with diabetes had higher fasting insulin. CONCLUSION: Asian Indians had lower HDL-C and LDL/apo B ratio than Chinese or Malays amongst normoglycaemic subjects. However, these differences between ethnic groups were not seen in subjects with DM.

Adolescent↗
PubMed2000

Impact to lung health of haze from forest fires: the Singapore experience.

OBJECTIVE: From late July to the beginning of October 1997, countries of Southeast Asia experienced severe smoke haze pollution from uncontrolled forest fires mainly in the Indonesian states of Kalimantan and Sumatra. In Singapore, the impact of the 1997 haze was felt in the period from the end of August to the first week of November 1997 as a result of prevailing winds. METHODOLOGY: The Ministry of the Environment monitors ambient air quality by a country-wide telemetric air quality monitoring and management network, with 15 stations located throughout the island, linked via a public telephone network to a central control station at the Environment Building. The monitoring methods used are the United States Environmental Protection Agency (USEPA) reference methods. The Pollutant Standards Index (PSI) developed by the USEPA is used for the reporting of daily air pollution concentrations. Intervals on the PSI scale are related to the potential health effects of the daily measured concentrations of the five major air pollutants: sulfur dioxide, particulate matter (PM10), nitrogen dioxide, ozone and carbon monoxide. Public sector health facilities which come under the Ministry of Health, have computerized patient care systems which enable the routine ongoing surveillance of disease conditions for the period of the haze. Attention during the period of the haze was focused on conditions related to health effects of the haze. Data sources for the monitoring of the lung health effects of the haze included morbidity from public sector outpatient care facilities, accidents and emergency departments, public sector inpatient care facilities and national mortality data. RESULTS: Findings from the health impact of the haze showed that there was a 30% increase in outpatient attendance for haze-related conditions. An increase in PM10 levels from 50 microg/m3 to 150 microg/m3 was significantly associated with increases of 12% of upper respiratory tract illness, 19% asthma and 26% rhinitis. Supplementary findings from scanning the electron microscopic sizing of the haze particles showed that 94% of the particles in the haze were below 2.5 microm in diameter. This was consistent with emissions from combustion sources originating over 500 km from Singapore. This has been of some concern because particles smaller than 2.5 microm in diameter can easily bypass normal body defence metabolism and penetrate deeply into the alveoli of the lungs. During the same period, there was also an increase in accident and emergency attendance for haze-related conditions. There was no significant increase in hospital admissions or in mortality. CONCLUSION: The present study found that the health effects from the 1997 smoke haze in Singapore were generally mild.

Air Pollutants↗
PubMed2000

Prevalence of primary aldosteronism among Asian hypertensive patients in Singapore.

Recent studies using the ratio of plasma aldosterone concentration (PAC) to PRA as the screening test for primary aldosteronism in hypertensive populations suggested that the prevalence may be as high as 5-15%, with well over half of the subjects having normal serum potassium concentrations. Despite an increasing clinical awareness of this entity, many clinicians are reluctant to consider routine screening for primary aldosteronism in essential hypertensive patients because there are few community-based prevalence studies of primary aldosteronism in different populations. Furthermore, genetic and environmental differences may affect the prevalence and presentation of primary aldosteronism in distinct populations. This study was designed to determine the prevalence of primary aldosteronism in the predominantly Chinese population in Singapore. Three hundred and fifty unselected adult hypertensive patients attending two primary care clinics had random ambulatory measurements for PAC (nanograms per dL) and PRA (nanograms per mL/h). Serum urea, creatinine, and electrolyte measurements were obtained simultaneously. Subjects with renal insufficiency (serum creatinine, >140 micromol/L) and those treated with glucocorticoids or spironolactone were excluded. Screening was considered positive if the PAC: PRA ratio was more than 20 and the PAC was more than 15 ng/dL (>416 pmol/L). Primary aldosteronism was confirmed with the determination of PAC after 2 L saline administered iv over 4 h. Adrenal computed tomographic (CT) scans were performed in biochemically confirmed cases of primary aldosteronism. Further localization with adrenal vein sampling was carried out in selected patients with equivocal findings on adrenal CT scan. Sixty-three (18%) of the 350 hypertensive patients (215 women and 135 men; age range, 23-75 yr) were screened positive for primary aldosteronism. Only 13 of these 63 subjects (21%) were hypokalemic (serum potassium, <3.5 mmol/L). Confirmatory studies were carried out in 56 (89%) of the subjects with a positive PAC:PRA ratio. Using a PAC above 10 ng/dL (>277 pmol/L) after saline infusion as the diagnostic cut-off, 16 of the 56 patients had biochemically confirmed primary aldosteronism. Hypokalemia was found in 6 of the 16 patients (37.5%) with primary aldosteronism. Subtype evaluation with adrenal CT scan and adrenal vein sampling indicated that half of the patients with primary aldosteronism may have had potentially curable unilateral adrenal adenoma. Our data suggest that primary aldosteronism occurs in at least 5% of the adult Asian hypertensive population, and approximately half of these individuals may have potentially curable, unilateral, aldosterone-producing adrenal adenoma. Our findings also confirm the poor predictive value of hypokalemia in both the diagnosis and the exclusion of primary aldosteronism.

Adult↗
PubMed2000

Vision screening of 4-year-old children in Singapore.

AIM OF THE STUDY: To evaluate the feasibility of an improved visual acuity screening program for Singapore 4-year-old preschool children and to draw up an appropriate referral criteria as well as evaluating the rates and outcomes of these referrals. METHOD: A total of 450 children aged 4 to 4 1/2 years, who attended 3 polyclinics of the Family Health Service (FHS) for their 4-year-old Developmental Health Screening during the study period from 1/4/1997 to 30/6/1997 were recruited for the study. Children who were tested with Snellen (or Sloan) visual acuity chart resulting in visual acuity of 6/9 or worse, or failed to pass the 3 mm medium plate at 30 cm distance (300 seconds of arc) in the Frisby Stereotest, or were found to have strabismus, or were untestable in either visual acuity test or stereotest were offered referral to ophthalmologists in the hospitals for specialist assessment. RESULT: 82.7% of the 450 children were successfully screened with Snellen (or Sloan) chart while 91.6% were successfully screened with Frisby Stereotest. In all, 180 children were evaluated by ophthalmologists. Majority of the children were referred because of their abnormal visual acuity test while only 2 children were referred for failing stereotest alone. Among the 180 children referred, 63 (35.0%) were found to have refractive errors for which spectacles were prescribed. Eight children had amblyopia and 2 children had strabismus which were not detected at the polyclinic screening. The untestable children evaluated had significantly higher abnormality rate (37.5%) than that of children who had 6/9 vision (8.8%) therefore they should be offered referral for further evaluation. There was high "refused referral" rate of 39.0%. Parents of children who were untestable or had 6/9 vision were found to be more likely to refuse offer of referral. If these two groups of children were excluded, the "refused referral" rate dropped to 13.3%. When the referral criteria for visual acuity was reset at 6/12 instead of 6/9, the referral rate dropped from 39.6% to a more manageable 26.7% and the positive predictive value improved from 35.4% to 48.3% and none of the children with amblyopia were missed being screened-out. CONCLUSION: The study confirmed the feasibility of doing visual acuity screening at 4 to 41/2 year-old. The referral criteria for abnormal visual acuity should be set at 6/12. The efficacy of adding Frisby stereotest needs further evaluation.

Age Factors↗
PubMed1999

Isolated low HDL cholesterol: an insulin-resistant state only in the presence of fasting hypertriglyceridemia.

Individuals with isolated low HDL cholesterol are at increased risk of coronary artery disease. It has been reported previously that this is an insulin-resistant state. We analyzed data from the 1992 Singapore National Health Survey with the objective of defining the clinical and metabolic parameters associated with isolated low HDL cholesterol. A total of 3,568 individuals were selected by stratified random sampling. Subjects with low HDL cholesterol (<0.9 mmol/l) and "ideal" total cholesterol (<5.2 mmol/l) were identified. Data on anthropometry, blood pressure (BP), insulin resistance, glucose tolerance, sex, smoking habit, and ethnic group were examined. We found that this group was heterogeneous. Those with fasting triglyceride (TG) >1.7 mmol/l (low HDL/high TG) displayed features of the insulin resistance syndrome characterized by obesity, higher diastolic BP, greater insulin resistance, and a greater tendency to have diabetes or impaired glucose tolerance (IGT). If fasting TG was <1.7 mmol/l (isolated low HDL cholesterol), individuals were similar to the general population in terms of insulin resistance and obesity. Both groups were more commonly men and Asian Indian. The ethnic difference in prevalence could not be explained by differences in diet, exercise, alcohol ingestion, or smoking. Our data support the view that Asian Indians are genetically predisposed to isolated low HDL cholesterol as well as the insulin resistance syndrome. The higher prevalence of isolated low HDL cholesterol, the young age at which individuals exhibit this phenotype (mean age 32.5 years), along with the greater propensity for Asian Indians to develop insulin resistance and IGT contribute to the threefold increased incidence of myocardial infarction in those <65 years of age in this ethnic group.

Adolescent↗
PubMed1999

Prevalence of diabetes and ethnic differences in cardiovascular risk factors. The 1992 Singapore National Health Survey.

OBJECTIVE: The purpose of the 1992 Singapore National Health Survey was to determine the current distribution of major noncommunicable diseases and their risk factors, including the prevalence of diabetes and dyslipidemia, in Singapore. RESEARCH DESIGN AND METHODS: A combination of disproportionate stratified sampling and systematic sampling were used to select the sample for the survey. The final number of respondents was 3,568, giving a response rate of 72.6%. All subjects fasted for 10 h and were given a 75-g glucose load, except those known to have diabetes. Blood was taken before and 2 h after the glucose load. Diagnosis of diabetes was based on 2-h glucose alone. RESULTS: The age-standardized prevalence of diabetes in Singapore residents aged 18-69 years was 8.4%, with more than half (58.5%) previously undiagnosed. Prevalence of diabetes was high across all three ethnic groups. The prevalence of impaired glucose tolerance was 16.1%, that of hypertension was 6.5%, and 19.0% were regular smokers. The total cholesterol (mean +/- SD) of nondiabetic Singaporeans was 5.18 +/- 1.02 mmol/l; 47.9% had cholesterol > 5.2 mmol/l, while 15.4% had levels > 6.3 mmol/l. Mean LDL cholesterol was 3.31 +/- 0.89 mmol/l; HDL cholesterol was 1.30 +/- 0.32 mmol/l, and triglyceride was 1.23 +/- 0.82 mmol/l. CONCLUSIONS: Prevalence of diabetes was high across all three ethnic groups. Ethnic differences in prevalence of diabetes, insulin resistance, central obesity, hypertension, smoking, and lipid profile could explain the differential coronary heart disease rates in the three major ethnic groups in Singapore.

Adolescent↗
PubMed1998

Population-based mammographic screening in Singapore: what are participants' views?

Mammographic screening for breast cancer has been shown to be an effective tool for reducing mortality from the disease in many studies in the West, if high technical quality and acceptance by the target population are achieved. The objective of the Singapore Breast Screening Project was to determine if the same results could be obtained among local women by inviting a random sample of 69,500 women aged 50 to 64 years for a screening mammogram over two years. To date, the compliance rate among the women invited has been 41.7%. The objective of the present substudy was to determine participants' views on the accessibility and acceptability of organised mammographic screening. Of the three hundred women interviewed, 85% were satisfied with the information given prior to the visit, while 67% needed to change the original appointment given. The majority were satisfied with aspects of the visit such as waiting time, privacy and explanation given during the test. However, 35.1% reported at least moderate discomfort during mammography. A substantial proportion (39.7%) of attenders felt that there was very little hope of cure even if cancer was detected early. When asked the most important reason for attending, most indicated they had taken the opportunity for a free check-up to be assured they were well. Almost all (95.7%) reported a willingness to be screened again, but most would not be willing to pay for a mammogram at the current rates.

Appointments and Schedules↗
PubMed1997

Factors determining acceptability of mammography in an Asian population: a study among women in Singapore.

Population-based mammographic screening has been shown to be effective in reducing breast cancer mortality in the West. In Singapore, a project carried out to determine the effectiveness of implementing such a program locally invited 28,000 women between the ages of 50 and 64 years for mammography. The current study, which was part of this larger project, was intended to determine factors contributing to the acceptance of mammographic screening among women in Singapore. A questionnaire was administered in-person to 300 attenders and 260 non-attenders. The respondents were compared with respect to basic demographic characteristics, previous preventive behavior, informal social support, and attitudes towards early detection. We found that screening attenders were more likely to be Chinese than Malays (14 percent of the population) or Indians (seven percent), and to be working outside the home (adjusted odds ratio [OR]) = 4.5, 95 percent confidence interval [CI] = 2.6-7.9). A greater proportion of attenders had a history of other screening tests such as the Pap smear (OR = 4.7, CI = 2.6-8.7 for recent smear compared with never having had a smear). They were also more likely to indicate a sense of personal susceptibility to cancer, but did not differ from non-attenders in terms of believing in cancer prevention, or of preferring to be told if they did have cancer. The strongest independent predictor of attendance, however, was encouragement by her spouse or family member. For women in this population to be persuaded effectively to participate in mammographic screening, it would be important to convince family members of the benefits of the test. At the same time, education targeted specifically at women of the appropriate age group should address the issue of the personal relevance of screening for breast cancer.

Breast Neoplasms↗
PubMed1997

Smoking.

Explore the source record for details and available documents.

Adolescent↗
PubMed1991

Cigarette smoking among school children in Singapore. Part III--Knowledge and attitudes towards smoking.

In the third article in this series which mainly assesses the knowledge of school children on the harmful effects of smoking, findings showed that the majority (90%) of school children surveyed were aware of the harmful effects. Current smokers appeared to be the least knowledgeable (69.4%) whilst non-smokers (89.3%) and experimenters (93.7%) were the most knowledgeable. Lung cancer (49%), smoking is bad for health (25%), smoking is bad for passive smokers (7%) and for heart disease (6%) were the most common responses given by the children on the specific ill effects caused by smoking. Smokers and non-smokers alike agreed that smoking is addictive, the proportions agreeing, once again, being lowest among smokers and highest among non-smokers. This trend was also observed when respondents were asked for their attitudes towards smoking--whether cigarette smoking was harmful and whether smoking made a person popular. The majority of respondents felt that a boy or girl who smoked "looked bad"--39% thought so of boys, while a higher proportion (55%), had the same impression of girls. The main reasons for giving up smoking given by ex-smokers were its harmful effects on health (49%), there being no more "kick" to it (16%), peer pressure (13%) and the disapproval of parents and teachers (13%). Among current smokers, at least half stated that they would like to stop smoking. Most of them had tried to kick the habit before but failed in their attempts. Finally, among the non-smokers, only 0.4% of boys and 0.1% of girls indicated that they might smoke in the future.

Adolescent↗
PubMed1991

Cigarette smoking among school children in Singapore. Part II--Development of the smoking habit.

The second in this series on smoking among school children in Singapore aims to define the characteristics of young smokers. Results show that of respondents who had ever smoked, the median age of experimentation with smoking was 12 years. This was seen among boys as well as girls. The median age at which current smokers went on to smoke regularly was 14 years, approximately two years after trying their first cigarette. Friends and parents were the main sources of the first cigarette for all categories of smokers, whether they be ex smokers, experimenters or current smokers. Among the reasons as to why current smokers smoked, the leading two were "to relax" (46.4%) and "out of sheer curiosity" (22.3%). Boys tend more to smoke with friends of the same sex (40.6%) whilst girls preferred mixed company (45.5%) when they smoked. Fathers played a major role in the development and continuation of smoking among those who had ever smoked before--52.0% of boys and 51.6% of girls currently smoking reported that their fathers smoked as well.

Adolescent↗
PubMed1991

Public awareness of AIDS in Singapore.

Singapore had 52 cases of AIDS as at June 1990. This places Singapore in the low-infection-load group of countries. Constant vigilance is necessary however. The Health education programme against AIDS in Singapore was launched in 1985. This first ever National Survey on public awareness of AIDS was carried out by the Research and Evaluation Department, Ministry of Health HQ, in late 1987, to assess the impact of the programme. It showed the level of knowledge of among Singaporeans to be high and comparable in many areas to that in the USA. The survey however also showed lack of credibility in the knowledge of AIDS among the public in certain important areas. This poses challenges to the public education programme.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Cigarette smoking among school children in Singapore. Part I--Smoking prevalence.

A cross sectional nationally representative survey of 33,110 school-going children in Singapore aged between 9 and 20 years was carried out to obtain, for the first time, baseline information on smoking among the school-going population in Singapore. The survey was carried out among students attending vocational institutes and public sector schools in Singapore in 1987. The overall smoking prevalence was found to be 2% (3% among boys and 0.2% among girls). Ex-smokers comprised 2% of respondents whilst those who had only experimented with smoking made up 9% of the respondents. Analyses of the data showed that cigarette smoking was more prevalent among Malays, among boys, among older children, and among the less academically inclined. On average, boys smoked a median of 20 cigarettes a week and girls, 12 cigarettes a week. On an international basis, the smoking prevalence among the school-going population in Singapore is significantly lower than that of developed countries like Australia, England and Wales and neighbouring countries such as Malaysia.

Adolescent↗