Distribution of ankle--brachial index and the risk factors of peripheral artery disease in a multi-ethnic Asian population.

Peripheral artery disease (PAD) is a manifestation of systemic atherosclerosis and is associated with increased cardiovascular morbidity and mortality. We describe the prevalence and risk factors of PAD in a multi-ethnic Asian population (Chinese, Malays and Indians) in Singapore. The Singapore Prospective Study Program recruited 4132 individuals between 2004 and 2006 in which the ankle-brachial index (ABI) was measured using the Smartdop™ 20EX bi-directional blood flow detector. PAD was defined as ≤ 0.9 and a high ABI > 1.4, with ABI 1.11-1.20 as reference. The mean age (SD) of individuals in the study was 49.9 (11.8) years, with 51.8% females. PAD was present in 4.3% of the population and a high ABI (> 1.4) was rare. Malays and Indians had a higher risk (especially in females). Compared to those with an ABI between 1.11 and 1.20, those with PAD were more likely to be of Malay and Indian ethnicity, female sex, with higher systolic blood pressure and pulse pressure, with increased prevalence of diabetes mellitus, hypertension, albuminuria and renal impairment, and with a past history of stroke. In conclusion, in this large multi-ethnic Asian population, we document the distribution and risk factor associations for PAD. PAD shows an ethnic distribution similar to that of coronary artery disease in Singapore, with differences in sex distribution. Apart from traditional vascular risk factors, pulse pressure, renal impairment and a past history of stroke are important determinants of PAD.

The metabolic syndrome and mortality: the Singapore Cardiovascular Cohort Study.

OBJECTIVE: This study assesses the effect of the metabolic syndrome on all-cause and cardiovascular disease (CVD) mortality in healthy Chinese, Malays and Asian Indians in Singapore. The utility of the metabolic syndrome is also compared with the Framingham risk score for prediction of mortality. METHODS: Healthy participants (n = 5699) were grouped by the presence or absence of the metabolic syndrome, and followed up (mean 14.1 years) by data linkage with the National Death Register. Risk of mortality was obtained by Cox's proportional hazards model with adjusted hazard ratios (HRs). Area under receiver operating characteristic (ROC) curves were used to compare the metabolic syndrome and Framingham risk score for prediction of mortality. RESULTS: During a follow-up of 80,236 person-years, there were 382 deaths, of which 128 were due to CVD. Individuals with the metabolic syndrome had an increased risk of mortality for 'all-causes' (males: HR 1.4, 95% confidence intervals (95%CI) 1.1-1.8; and females: HR 1.8, 95%CI 1.3-2.6). There was also an increased risk of mortality due to CVD (males: HR 3.0, 95%CI 1.9-4.8; and females: HR 2.1, 95%CI 1.1-4.0). The area under ROC for Framingham risk score was higher for both all-cause and CVD mortality than metabolic syndrome. CONCLUSIONS: Although an increased risk of 'all-cause' and CVD mortality due to the metabolic syndrome was found, the Framingham risk function still performed better than the metabolic syndrome in an Asian population. However, the metabolic syndrome should not be disregarded as it is a clinically useful entity for identifying individuals for management of its component CVD risk factors.

Should central obesity be an optional or essential component of the metabolic syndrome? Ischemic heart disease risk in the Singapore Cardiovascular Cohort Study.

OBJECTIVE: The International Diabetes Federation (IDF) proposes that central obesity is an "essential" component of the metabolic syndrome, while the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) proposes that central obesity is an "optional" component. This study examines the effect of the metabolic syndrome with and without central obesity in an Asian population with ischemic heart disease (IHD). RESEARCH DESIGN AND METHODS: From the population-based cohort study (baseline 1992-1995), 4,334 healthy individuals were grouped by the presence or absence of the metabolic syndrome and central obesity and followed up for an average of 9.6 years by linkage with three national registries. Cox's proportional hazards model was used to obtain adjusted hazard ratios (HRs) for risk of a first IHD event. RESULTS: The prevalence of metabolic syndrome was 17.7% by IDF criteria and 26.2% by AHA/NHLBI criteria using Asian waist circumference cutoff points for central obesity. Asian Indians had higher rates than Chinese and Malays. There were 135 first IHD events. Compared with individuals without metabolic syndrome, those with central obesity/metabolic syndrome and no central obesity/metabolic syndrome were at significantly increased risk of IHD, with adjusted HRs of 2.8 (95% CI 1.8-4.2) and 2.5 (1.5-4.0), respectively. CONCLUSIONS: Having metabolic syndrome either with or without central obesity confers IHD risk. However, having central obesity as an "optional" rather than "essential" criterion identifies more individuals at risk of IHD in this Asian cohort.

Impact of sex, metabolic syndrome, and diabetes mellitus on cardiovascular events.

Although cardiovascular events occur more frequently among patients with metabolic syndrome (MS) or diabetes mellitus (DM), the impact of gender is unclear. We aimed to determine the relation of MS and DM on cardiovascular events between men and women. The National Health Survey of 1992 provided information on outcomes for 3,414 Singaporeans aged 18 to 69 years without cardiovascular diseases. Definition of MS was based on the National Cholesterol Education Program criteria. Cardiovascular events included hospital admissions for coronary heart disease, stroke, and cardiovascular mortality. The proportion of subjects with MS was 12.4%. After 10 years, the annual cardiovascular event rates (per 1,000 person-years) for men without DM were 3.0 and 15.9 among subjects without and with MS, respectively, and the respective rates for men with DM were 22.5 and 21.4. The corresponding rates for women were 0.9, 3.7, 5.3, and 21.5, respectively. Among nondiabetic subjects, cardiovascular events occurred more frequently among men than women among subjects with MS (adjusted hazard ratios [HRs] 4.71, 95% confidence interval [CI] 1.56 to 14.2) and those without MS (HR 3.35, 95% CI 1.78 to 6.31). Among patients with DM, cardiovascular events occurred more commonly among men than women without MS (HR 6.04, 95% CI 1.43 to 25.6). Rates for cardiovascular events were comparable between men and women with DM and MS (HR 0.98, 95% CI 0.48 to 1.99). In conclusion, the adverse impact of MS or DM was greater among men, and the presence of both conditions increases the risk substantially for cardiovascular events among women.

Risk factors for contact lens-related fusarium keratitis: a case-control study in Singapore.

OBJECTIVE: To evaluate the specific contact lens-related or other factors that may contribute to the outbreak of Fusarium keratitis. METHODS: A case-control study was conducted of Fusarium keratitis in contact lens users in Singapore from March 1, 2005, to May 31, 2006, and included 61 patients with Fusarium keratitis and 188 population-based and 179 hospital-based control subjects. Interviewers asked about contact lens solution use and other risk factors. RESULTS: Patients with Fusarium keratitis were more likely to use ReNu contact lens solutions (Bausch & Lomb, Rochester, NY) 58 [95.1%] of 61 cases) than were either population-based (62 [34.3%] of 181) or hospital-based (50 [30.1%] of 166) control subjects. After controlling for age, sex, contact lens hygiene, and other factors, the use of ReNu with MoistureLoc significantly increased the risk of Fusarium keratitis (odds ratio, 99.3; 95% confidence interval, 18.4-535.4; P<.001), and the risk was 5 times higher compared with the risk with use of ReNu MultiPlus, a multipurpose solution (odds ratio, 21.5; 95% confidence interval, 4.0-115.5; P<.001). CONCLUSIONS: The use of ReNu contact lens solutions significantly increased the risk of contact lens-related Fusarium keratitis in Singapore. Our data support the recall of ReNu MultiPlus from the Singapore market and the need for further investigations into the role of ReNu MultiPlus in the development of Fusarium keratitis in other populations.

Gender, ethnicity, health behaviour & self-rated health in Singapore.

BACKGROUND: Self-rated health and the factors that influence it have never been described in Singapore before. This paper presents a descriptive study of self-rated health in a nationally representative cross-sectional survey of 6236 persons. METHODS: As part of the National Health Surveillance Survey 2001, 6236 subjects aged 18 years and above were interviewed in the homes of participants by trained interviewers. The subjects were asked "In general, how would you rate your health today?", and given 5 possible responses. These were then categorized as "Good" (very good and good) and "Poor" (moderate, bad and very bad) self-rated health. The association of socio-economic and health behaviour risk factors with good self-rated health was studied using univariate and multivariate logistic regression analysis. RESULTS: Univariate analyses suggest that gender, ethnicity, marital status, education, household income, age, self-reported doctor-diagnosed illnesses, alcohol intake, exercise and BMI are all associated with poor self-rated health. In multivariate regression analyses, gender, ethnicity, household income, age, self-reported illness and current smoking and BMI were associated with poor self-rated health. There are gender differences in the association of various factors such as household income, smoking and BMI to self-rated health. CONCLUSION: Socioeconomic factors and health behaviours are significantly associated with self-rated health, and gender differences are striking. We discuss why these factors may impact self-rated health and why gender differences may have been observed, propose directions for further research and comment on the public policy implications of our findings.

Perilipin gene variation determines higher susceptibility to insulin resistance in Asian women when consuming a high-saturated fat, low-carbohydrate diet.

OBJECTIVE: To investigate the association between genetic variation in the adipocyte protein perilipin (PLIN) and insulin resistance in an Asian population as well as to examine their modulation by macronutrient intake. RESEARCH DESIGN AND METHODS: A nationally representative sample (Chinese, Malays, and Indians) was selected in the Singapore National Health Survey following the World Health Organization-recommended model for field surveys of diabetes. A total of 1,909 men and 2,198 women (aged 18-69 years) were studied. Genetic (PLIN 11482G-->A and 14995A-->T), lifestyle, clinical, and biochemical data were obtained. Homeostasis model assessment of insulin resistance (HOMA-IR) was used to evaluate insulin resistance. Diet was measured by a validated food frequency questionnaire in one of every two subjects. RESULTS: We did not find a significant between-genotype difference in insulin resistance measures. However, in women we found statistically significant gene-diet interactions (recessive model) between PLIN 11482G-->A/14995A-->T polymorphisms (in high linkage disequilibrium) and saturated fatty acids (SFAs; P = 0.003/0.005) and carbohydrate (P = 0.004/0.012) in determining HOMA-IR. These interactions were in opposite directions and were more significant for 11482G-->A, considered the tag polymorphism. Thus, women in the highest SFA tertile (11.8-19%) had higher HOMA-IR (48% increase; P trend = 0.006) than women in the lowest (3.1-9.4%) only if they were homozygotes for the PLIN minor allele. Conversely, HOMA-IR decreased (-24%; P trend = 0.046) as carbohydrate intake increased. These effects were stronger when SFAs and carbohydrate were combined as an SFA-to-carbohydrate ratio. Moreover, this gene-diet interaction was homogeneously found across the three ethnic groups. CONCLUSIONS: PLIN 11482G-->A/14995A-->T polymorphisms modulate the association between SFAs/carbohydrate in diet and insulin resistance in Asian women.

The V227A polymorphism at the PPARA locus is associated with serum lipid concentrations and modulates the association between dietary polyunsaturated fatty acid intake and serum high density lipoprotein concentrations in Chinese women.

Peroxisome proliferators activated receptor alpha (PPARalpha) regulates the transcription of several proteins involved in human lipoprotein metabolism. We screened the PPARA locus for polymorphisms in 20 unrelated subjects from each of three ethnic groups (Chinese, Malays and Asian Indians). Only the V227A polymorphism was observed. We genotyped 4248 subjects (2899 Chinese, 761 Malay and 588 Asian Indians) and found allele frequencies for the A227 allele of 0.04 in Chinese, 0.006 in Malays and 0.003 in Asian Indians. We examined the associations between this polymorphism and serum lipid concentrations in Chinese. In women, but not in men, the presence of the A227 allele was associated with lower serum concentrations of total cholesterol [5.38mmol/l (95%CI: 5.22-5.54) versus 5.21mmol/l (95%CI: 4.99-5.43), p=0.047] and triglycerides [1.19mmol/l (95%CI: 1.10-1.28) versus 1.09mmol/l (95%CI: 0.98-1.21), p=0.048]. We also found that the V227A polymorphism modulates the association between dietary polyunsaturated fatty acid intake and serum high density lipoprotein concentration (p-value for interaction=0.049). Our findings implicate PPARalpha in the lipid lowering associated with diets high in PUFA and suggests that genetic variation at the PPARA locus may determine the lipid response to changes in PUFA intake.

Modification of the NCEP ATP III definitions of the metabolic syndrome for use in Asians identifies individuals at risk of ischemic heart disease.

The association between the metabolic syndrome (MS) to ischemic heart disease (IHD) has not been established prospectively in Asian populations. We carried out registry linkage, using unique national identity numbers, to identify incident IHD events in subjects without diabetes mellitus or IHD from two cross-sectional studies of Chinese, Malays and Asian Indians living in Singapore. The risk of IHD associated with the MS (NCEP ATP III criteria) was determined by Cox-proportional hazards regression before and after adjustment for age, sex, ethnic group and current cigarette smoking. We also assessed the utility of modified Asian criteria (reducing the waist circumference (WC) used to define central obesity to 90 cm in men and 80 cm in women) on the risk of IHD associated with the MS. This study provided 38,157.4 person-years in 4042 subjects who experienced 93 incident IHD events. MS (as defined by the NCEP ATP III criteria) was associated with increased risk of IHD (HR3.09; 95% CI 1.96-4.88). Those who satisfied only the modified Asian criteria, but not the NCEP ATP III criteria, were also at increased risk of IHD (HR 2.13; 95% CI 0.99-4.58). It would be appropriate to lower the cut-off for WC used for the diagnosis of the MS in such populations.

Intragenic linkage disequilibrium structure of the human perilipin gene (PLIN) and haplotype association with increased obesity risk in a multiethnic Asian population.

Perilipin is a lipid droplet surface protein present in adipocytes and steroidogenic cells. We examined five common single nucleotide polymorphisms (SNPs) at the perilipin (PLIN) locus (PLIN 6209C>T, 10171A>T, 11482G>A, 13041A>G, and 14995A>T) to investigate their association with obesity risk. The study population included 4,131 subjects of three ethnic groups (Chinese, Malay, and Indian) from Singapore. The prevalence of obesity in Malays and Indians was much higher than in Chinese. Moreover, in these groups the prevalence of obesity was three times higher in women than in men. Crude analysis indicated that haplotype 11212 (CAAAT) is shared by Malays and Indians and is significantly associated with increased obesity risk as compared to the most common haplotype 21111 (TAGAA): OR 1.65 (95% CI 1.11-2.46) in Malays and 1.94 (95% CI 1.06-3.53) in Indians. No associations between PLIN haplotypes and obesity risk were found in Chinese. To simplify the haplotype analyses we used a subgroup of three SNPs (11482G>A, 13041A>G, and 14995A>T) in positive linkage disequilibrium. These analyses revealed similar associations, showing that haplotypes XX212 (XXAAT) and XX222 (XXAGT) are associated with increased obesity risk in Malays OR 2.04 (95% CI 1.28-3.25) and 2.05 (95% CI 1.35-3.12) respectively, and that haplotype XXX212 (XXAAT) is significantly associated with increased obesity risk in Indians OR 2.16 (95% CI 1.10-4.26) after adjusting for covariates including age, sex, smoking, alcohol consumption, exercise, and diabetes status. Moreover, individual SNP analyses demonstrated that the PLIN 14995A>T SNP is the most informative single genetic marker for the observed haplotype association, being significantly associated with increased obesity risk in both Malays OR 2.28 (95% CI 1.45-3.57) and Indians OR 2.04 (95% CI 1.08-3.64). These results support the role of the PLIN locus as an ethnically dependent modulator of obesity risk in humans.

Epidemiology and control of SARS in Singapore.

Severe acute respiratory syndrome (SARS) was imported into Singapore in late February 2003 by a local resident who returned from a holiday in Hong Kong and started an outbreak in the hospital where she was admitted on 1 March 2003. The disease subsequently spread to 4 other healthcare institutions and a vegetable wholesale centre. During the period between March and May 2003, 238 probable SARS cases, including 8 imported cases and 33 deaths, were reported. Transmission within the healthcare and household settings accounted for more than 90% of the cases. Factors contributing to the spread of infection included the failure to recognise the high infectivity of this novel infection, resulting in a delay in isolating initial cases and contacts and the implementation of personal protective measures in healthcare institutions; and the super-spreading events by 5 index cases, including 3 with co-morbid conditions presenting with atypical clinical manifestations of SARS. Key public health measures were directed at prevention and control within the community and hospitals, and the prevention of imported and exported cases. An isolated laboratory-acquired case of SARS was reported on 8 September 2003. Based on the lessons learnt, Singapore has further strengthened its operational readiness and laboratory safety to respond to SARS, avian flu and other emerging diseases.

Use of quarantine in the control of SARS in Singapore.

BACKGROUND: A total of 238 cases of the severe acute respiratory syndrome (SARS) occurred in Singapore between February 25 and May 11, 2003. Control relied on empirical methods to detect early and isolate all cases and quarantine those who were exposed to prevent spread in the community. METHODS: On April 28, 2003, the Infectious Diseases Act was amended in Parliament to strengthen the legal provisions for serving the Home Quarantine Order (HQO). In mounting large-scale quarantine operations, a framework for contact tracing, serving quarantine orders, surveillance, enforcement, health education, transport, and financial support was developed and urgently put in place. RESULTS: A total of 7863 contacts of SARS cases were served with an HQO, giving a ratio of 38 contacts per case. Most of those served complied well with quarantine; 26 (0.03%) who broke quarantine were penalized. CONCLUSION: Singapore's experience underscored the importance of being prepared to respond to challenges with extraordinary measures. With emerging diseases, health authorities need to rethink the value of quarantine to reduce opportunities for spread from potential reservoirs of infection.

The metabolic syndrome in Chinese, Malays and Asian Indians. Factor analysis of data from the 1998 Singapore National Health Survey.

We used factor analysis to define and compare the manner in which the various features of the metabolic syndrome are linked or clustered in Chinese, Malays and Asian Indians. One thousand nine hundred and fifty seven men (1324 Chinese, 391 Malays and 261 Asian Indians) and 2308 women (1622 Chinese, 391 Malays and 296 Asian Indians) were examined. Anthropometry, blood pressure, serum glucose, lipid concentrations, and serum insulin were measured for all subjects. These data were then subjected to factor analysis which reduced the variables examined to three factors in all ethnic groups and both genders. The first (dyslipidemia) factor was positively loaded for obesity, insulin resistance (IR), fasting triglyceride and negatively loaded for HDL-cholesterol. The second (hyperglycemia) factor was positively loaded for IR and blood glucose. The third (hypertension) factor was positively loaded for obesity and blood pressure. IR was positively loaded in the hypertension factor in Malay women but not in others. Rather than a single entity causally associated with insulin resistance (IR), our findings support a concept in which the metabolic syndrome represents several distinct entities (dyslipidemia, hypertension and hyperglycemia). It appears that Malay females may be more prone to develop hypertension in association with IR.

Can we apply the National Cholesterol Education Program Adult Treatment Panel definition of the metabolic syndrome to Asians?

OBJECTIVE: Limited information is available about the metabolic syndrome in Asians. Furthermore, the definition of central obesity using waist circumference may not be appropriate for Asians. The objectives of this study were to determine the optimal waist circumference for diagnosing central obesity in Asians and to estimate the prevalence of the metabolic syndrome in an Asian population. RESEARCH DESIGN AND METHODS: We used data from the 1998 Singapore National Health Survey, a cross-sectional survey involving 4,723 men and women of Chinese, Malay, and Asian-Indian ethnicity aged 18-69 years. Receiver operating characteristic analysis suggested that waist circumference >80 cm in women and >90 cm in men was a more appropriate definition of central obesity in this population. The prevalence of the metabolic syndrome was then determined using the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria with and without the modified waist circumference criteria. RESULTS: In Asians, decreasing waist circumference increased the crude prevalence of the metabolic syndrome from 12.2 to 17.9%. Using the modified Asian criteria, the prevalence of the metabolic syndrome increased from 2.9% in those aged 18-30 years to 31.0% in those aged 60-69 years. It was more common in men (prevalence 20.9% in men versus 15.5% in women; P < 0.001) and Asian Indians (prevalence 28.8% in Asian-Indians, 24.2% in Malays, and 14.8% in Chinese; P < 0.001). CONCLUSIONS: NCEP ATP III criteria, applied to an Asian population, will underestimate the population at risk. With a lower waist circumference cutoff, the prevalence of the metabolic syndrome is comparable to that in Western populations. Ethnic differences are likely to exist between populations across Asia.

The Singapore impaired glucose tolerance follow-up study: does the ticking clock go backward as well as forward?

OBJECTIVE: To 1). document the change in glucose tolerance for subjects with normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) over time, 2). identify baseline factors associated with worsening of glucose tolerance, and 3). determine whether cardiovascular disease (CVD) risk factors associated with IGT improved in tandem with glucose tolerance. RESEARCH DESIGN: Subjects with IGT and NGT (matched for age, sex, and ethnic group) were identified from a cross-sectional survey conducted in 1992. Subjects with IGT (297) and NGT (298) (65.0%) were reexamined in 2000. Glucose tolerance (assessed by 75-g oral glucose tolerance test), anthropometric data, serum lipids, blood pressure, and insulin resistance were determined at baseline and at the follow-up examination. RESULTS: For NGT subjects, 14.0% progressed to IGT and 4.3% to diabetes over 8 years. For IGT subjects, 41.4% reverted to NGT, 23.0% remained impaired glucose tolerant, and 35.1% developed diabetes. Obesity, hypertriglyceridemia, higher blood pressure, increased insulin resistance, and lower HDL cholesterol at baseline were associated with worsening of glucose tolerance in both IGT and NGT subjects. Those with IGT who reverted to NGT remained more obese and had higher blood pressure than those with NGT in both 1992 and 2000. However, serum triglyceride, HDL cholesterol, and insulin resistance values in 2000 became indistinguishable from those of subjects who maintained NGT throughout the study period. CONCLUSIONS: Some, but not all, CVD risk factors associated with IGT and with the risk of future diabetes normalize when glucose tolerance normalizes. Continued surveillance and treatment in subjects with IGT, even after they revert to NGT, may be important in the prevention of CVD.

Lowering the criterion for impaired fasting glucose: impact on disease prevalence and associated risk of diabetes and ischemic heart disease.

OBJECTIVE: To determine the effect of lowering the fasting plasma glucose (FPG) criterion for impaired fasting glucose (IFG) on the prevalence of IFG, the risks of diabetes, and cardiovascular disease (CVD) associated with IFG. RESEARCH DESIGN AND METHODS: Three studies were used: 1). the 1998 National Health Survey (NHS98), a randomly selected cross-sectional sample of 4723 subjects; 2). the Singapore Impaired Glucose Tolerance (IGT) Follow-up Study, a cohort study comprising 295 IGT and 292 normal glucose tolerance subjects (frequency matched for age, sex, and ethnic group) followed up from 1992 to 2000; and 3). the Singapore CVD Cohort Study, comprising 5920 subjects from three cross-sectional studies in whom the first ischemic heart disease (IHD) event was identified through linkage to registry databases. Risk of diabetes (Singapore IGT Follow-up study) was estimated using logistic regression adjusted for age, sex, and ethnicity. Risk of IHD (Singapore CVD cohort) was estimated using stratified (by study, from which data were derived) Cox's proportional hazards models adjusted for age, sex, and ethnicity. RESULTS: Lowering the criterion for diagnosing IFG to 5.6 mmol/l increased the prevalence of IFG from 9.5 to 32.3% in the NHS98. The lower cutoff identified more subjects at risk of diabetes and IHD, but the relative risk was lower than that for IGT. CONCLUSIONS: Greater efforts to identify those with IGT, or a group at similar risk of diabetes and CVD, may be a more efficient public health measure than lowering the FPG criterion for diagnosing IFG.

Age- and sex-specific prevalence of diabetes and impaired glucose regulation in 11 Asian cohorts.

OBJECTIVE: To report the age- and sex-specific prevalence of diabetes and impaired glucose regulation (IGR) according to revised World Health Organization criteria for diabetes in Asian populations. RESEARCH DESIGN AND METHODS: We performed 11 studies of 4 countries, comprising 24,335 subjects (10,851 men and 13,484 women) aged 30-89 years who attended the 2-h oral glucose tolerance test and met the inclusion criteria for data analysis. RESULTS: The prevalence of diabetes increased with age and reached the peak at 70-89 years of age in Chinese and Japanese subjects but peaked at 60-69 years of age followed by a decline at the 70 years of age in Indian subjects. At 30-79 years of age, the 10-year age-specific prevalence of diabetes was higher in Indian than in Chinese and Japanese subjects. Indian subjects also had a higher prevalence of IGR in the younger age-groups (30-49 years) compared with that for Chinese and Japanese subjects. Impaired glucose tolerance was more prevalent than impaired fasting glycemia in all Asian populations studied for all age-groups. CONCLUSIONS: Indians had the highest prevalence of diabetes among Asian countries. The age at which the peak prevalence of diabetes was reached was approximately 10 years younger in Indian compared with Chinese and Japanese subjects. Diabetes and IGR will be underestimated in Asians based on the fasting glucose testing alone.

HIV in Singapore--past, present, and future.

The first case of HIV infection in Singapore was reported in 1985. Between 1991 and 1998, the number of reported cases of HIV and AIDS increased rapidly before stabilizing from 1999. The epidemiology of the AIDS epidemic in Singapore is characterized by a predominance of male cases (seven to one) and heterosexual transmission. A multipronged control program comprising public education and education of high-risk groups, legislation, protection of the national blood supply, management of cases, and epidemiological surveillance has been put in place. The promotion of condom use among local sex workers has been fairly successful, with very low rates of HIV and other sexually transmitted infections (STIs). However, freelance and potential indirect sex workers such as masseuses and lounge hostesses are a concern in view of their higher prevalence of HIV and STIs. Another concern is the high proportion of cases who are diagnosed only when they develop AIDS. A better understanding of sexual networks among men who have sex with men will enable more effective intervention programs for this group. Fresh innovative approaches are needed to encourage safe sex practices and early screening.

Ethnic differences in utilization of invasive cardiac procedures and in long-term survival following acute myocardial infarction.

BACKGROUND: Ethnic differences in coronary mortality have been documented, and South Asians from the Indian subcontinent are particularly vulnerable. HYPOTHESIS: This study sought to determine whether there was a difference in the utilization of invasive cardiac procedures and long-term mortality in survivors of myocardial infarction (MI) among Chinese, Malays, and South Asians in Singapore. METHODS: All MI events in the country were identified and defined by the Singapore Myocardial Infarction Register, which uses modified procedures of the World Health Organization MONICA Project. Information on utilization of coronary angiography, coronary angioplasty, coronary artery bypass graft, and survival was obtained by data linkage with national billing and death registries. Hazard ratios (HR) were calculated using the Cox proportional hazards model with adjustment for baseline characteristics. RESULTS: From 1991 to 1999, there were 10,294 patients who survived > or = 3 days of MI. Of these, 40.6% underwent coronary angiography and 16.5% a revascularization procedure < or = 28 days. Malays received substantially less angiography (34.0%) and revascularization (11.4%) than Chinese (41.9%, 17.9%) and South Asians (40.0%, 16.3%). The ethnic disparity increased during the 1990s, particularly in the performance of coronary angiography (p = 0.038). While fatality declined during the study period for Chinese and South Asians, the rate remained stable for Malays. After a median follow-up period of 4.1 years, survival was lowest among Malays (adjusted HR, 1.28; 95% confidence interval, 1.15-1.42, compared with Chinese). CONCLUSION: Ethnic inequalities in invasive cardiac procedures exist in Singapore and were exacerbated in the 1990s. Inequalities in medical care may contribute to the poorer longterm survival among Malays.

Epidemiology of acute hepatitis E in Singapore.

OBJECTIVES: We undertook an epidemiological review to determine the trend and characteristics of acute hepatitis E in Singapore over the last 12 years. METHODS: We analysed the epidemiological records of all laboratory-confirmed cases of acute hepatitis E maintained at the Communicable Diseases Division, Ministry of Health, from 2000 to 2011. RESULTS: A total of 540 laboratory-confirmed cases of acute hepatitis E was reported with more than half imported, mainly from India and Bangladesh. Among the indigenous cases, the mean annual incidence per 100,000 population increased from 0.05 in 2000-2002 to 0.92 in 2009-2011. There was a male predominance and the median age was 46 years. Among the 3 major ethnic groups of Singapore residents, Chinese and Indians had higher mean annual incidence rate compared to Malays. All the indigenous cases occurred singly and sporadically and could not be epidemiologically linked to one another by person, place or time. No common food item was implicated. CONCLUSIONS: Indigenous acute hepatitis E has emerged as a major cause of acute viral hepatitis in Singapore. While epidemiological investigations are ongoing to elucidate the risk factors and modes of transmission, travellers should be reminded to practise a high standard of personal and food hygiene when visiting endemic countries.