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.

Certification of poliomyelitis eradication in Singapore and the challenges ahead.

INTRODUCTION: This study reviewed the epidemiological trends of poliomyelitis from 1946 to 2010, and the impact of the national immunisation programme in raising the population herd immunity against poliovirus. We also traced the efforts Singapore has made to achieve certification of poliomyelitis eradication by the World Health Organisation. MATERIALS AND METHODS: Epidemiological data on all reported cases of poliomyelitis were obtained from the Communicable Diseases Division of the Ministry of Health as well as historical records. Coverage of the childhood immunisation programme against poliomyelitis was based on the immunisation data maintained by the National Immunisation Registry, Health Promotion Board. To assess the herd immunity of the population against poliovirus, 6 serological surveys were conducted in 1962, 1978, 1982 to 1984, 1989, 1993 and from 2008 to 2010. RESULTS: Singapore was among the fi rst countries in the world to introduce live oral poliovirus vaccine (OPV) on a mass scale in 1958. With the comprehensive coverage of the national childhood immunisation programme, the incidence of paralytic poliomyelitis declined from 74 cases in 1963 to 5 cases from 1971 to 1973. The immunisation coverage for infants, preschool and primary school children has been maintained at 92% to 97% over the past decade. No indigenous poliomyelitis case had been reported since 1978 and all cases reported subsequently were imported. CONCLUSION: Singapore was certified poliomyelitis free along with the rest of the Western Pacific Region in 2000 after fulfilling all criteria for poliomyelitis eradication, including the establishment of a robust acute flaccid paralysis surveillance system. However, post-certification challenges remain, with the risk of wild poliovirus importation. Furthermore, it is timely to consider the replacement of OPV with the inactivated poliovirus vaccine in Singapore's national immunisation programme given the risk of vaccine-associated paralytic poliomyelitis and circulating vaccine-derived polioviruses.

Determinants of late-stage HIV disease at diagnosis in Singapore, 1996 to 2009.

INTRODUCTION: The delay in HIV diagnosis has been identified as a significant reason for late presentation to medical care. This research aims to elucidate the significant determinants of late-stage HIV infection in Singapore between 1996 and 2009, after the advent of highly active anti-retroviral therapies. MATERIALS AND METHODS: We included 3735 patients infected via sexual mode of transmission from the National HIV Registry diagnosed between 1996 and 2009. Late-stage HIV infection is defined as CD4 count less than 200 mm(3) or AIDS-defining opportunistic infections at fi rst diagnosis or within one year of HIV diagnosis. We determined independent epidemiological risk factors for late-stage HIV infection at first diagnosis using multivariate logistic regression. RESULTS: Multivariate analysis showed that older age corresponded significantly with increasing odds of late-stage HIV infection. Compared to persons diagnosed at 15 to 24 years of age, those diagnosed at age 55 years and above were associated with 5-fold increased likelihood of late-stage infection (adjusted odds ratio (AOR): 5.17; 95% CI, 3.21 to 8.33). Chinese ethnicity, singlehood, and non-professional occupations were also significantly associated with late-stage HIV infection. Persons detected in the course of medical care had over 3.5 times the odds of late-stage infection (AOR: 3.55; 95% CI, 2.71 to 4.65). Heterosexual mode of transmission and having sex workers and social escorts as sexual partners, were the other epidemiological risk factors with significant associations. CONCLUSION: The findings of this study emphasises the need to increase HIV awareness and to encourage early and regular HIV testing among at-risk persons.

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.

Changing seroprevalence of hepatitis B virus markers of adults in Singapore.

INTRODUCTION: We presented the findings from 2 seroprevalence studies conducted 6 years apart, so as to determine changes in the hepatitis B surface antigen (HBsAg) positivity rate and immunity to hepatitis B virus (HBV) among Singapore residents aged 18 to 69 years, and to assess the impact of a 4-year catch-up hepatitis B immunisation programme for adolescents and young adults launched in 2001. MATERIALS AND METHODS: Two hepatitis B seroprevalence studies (HBSS) were conducted in 1999 and 2005 based on stored blood samples collected from 4698 participants aged 18 to 69 years during the national health survey (NHS) 1998 and from 3460 participants during the NHS 2004, respectively. Serology for HBsAg, hepatitis B e antigen (HBeAg) and antibody to HBsAg (anti-HBs) were tested by enzyme immunoassay in HBSS 1999 and electrochemiluminescence in HBSS 2005. RESULTS: The overall age-standardised prevalence of HBsAg among Singapore residents aged 18 to 69 years decreased significantly from 4.0% in HBSS 1999 to 2.8% in HBSS 2005 (P = 0.002). The age-standardised prevalence of HBsAg in males (4.9% in 1999) and Chinese (4.7% in 1999) both decreased significantly to 2.7% and 2.8%, respectively in 2005. The overall age-standardised population immunity to HBV (anti-HBs >10 mIU/ml) increased from 39.7% in 1999 to 42.1% in 2005 (P = 0.019). In particular, the age-specific prevalence of anti-HBs showed a significant increase among those in the age group of 18 to 29 years from 27.9% in 1999 to 41.7% in 2005 (P <0.001) and among those in the age group of 30 to 39 years from 39.9% in 1999 to 44.7% in 2005 (P = 0.021). CONCLUSION: There was an overall decline in the HBsAg positivity rate as well as an overall increase in population immunity to HBV. Following the 4-year catch-up immunisation programme, there was a significant increase in the immunity to HBV infection in the younger population aged 18 to 29 years.

Polymorphisms identified through genome-wide association studies and their associations with type 2 diabetes in Chinese, Malays, and Asian-Indians in Singapore.

CONTEXT: Novel type 2 diabetes mellitus (T2DM) susceptibility loci, identified through genome-wide association studies (GWAS), have been replicated in many European and Japanese populations. However, the association in other East Asian populations is less well characterized. OBJECTIVE: To examine the effects of SNPs in CDKAL1, CDKN2A/B, IGF2BP2, HHEX, SLC30A8, PKN2, LOC387761, and KCNQ1 on risk of T2DM in Chinese, Malays, and Asian-Indians in Singapore. DESIGN: We genotyped these candidate single-nucleotide polymorphisms (SNPs) in subjects from three major ethnic groups in Asia, namely, the Chinese (2196 controls and 1541 cases), Malays (2257 controls and 1076 cases), and Asian-Indians (364 controls and 246 cases). We also performed a metaanalysis of our results with published studies in East Asians. RESULTS: In Chinese, SNPs in CDKAL1 [odds ratio (OR) = 1.19; P = 2 x 10(-4)], HHEX (OR = 1.15; P = 0.013), and KCNQ1 (OR = 1.21; P = 3 x 10(-4)) were significantly associated with T2DM. Among Malays, SNPs in CDKN2A/B (OR = 1.22; P = 3.7 x 10(-4)), HHEX (OR = 1.12; P = 0.044), SLC30A8 (OR = 1.12; P = 0.037), and KCNQ1 (OR = 1.19-1.25; P = 0.003-2.5 x 10(-4)) showed significant association with T2DM. The combined analysis of the three ethnic groups revealed significant associations between SNPs in CDKAL1 (OR = 1.13; P = 3 x 10(-4)), CDKN2A/B (OR = 1.16; P = 9 x 10(-5)), HHEX (OR = 1.14; P = 6 x 10(-4)), and KCNQ1 (OR = 1.16-1.20; P = 3 x 10(-4) to 3 x 10(-6)) with T2DM. SLC30A8 (OR = 1.06; P = 0.039) showed association only after adjustment for gender and body mass index. Metaanalysis with data from other East Asian populations showed similar effect sizes to those observed in populations of European ancestry. CONCLUSIONS: SNPs at T2DM susceptibility loci identified through GWAS in populations of European ancestry show similar effects in Asian populations. Failure to detect these effects across different populations may be due to issues of power owing to limited sample size, lower minor allele frequency, or differences in genetic effect sizes.

Seroepidemiology of dengue virus infection among adults in Singapore.

INTRODUCTION: To determine the seroepidemiology of dengue virus infection in a representative sample of the adult resident population aged 18 years old to 74 years old in Singapore and to estimate the proportion of asymptomatic dengue infection during the 2004 epidemic. MATERIALS AND METHODS: The study was based on 4152 stored blood samples collected between September and December 2004 from participants aged 18 years old to 74 years old during the 2004 National Health Survey. Sera were tested for IgG and IgM antibodies using a commercial test kit (PanBio Capture/Indirect ELISA). RESULTS: Of the study population, 59.0% and 2.6% tested positive for dengue IgG (past infection) and IgM/high-titre IgG (recent infection), respectively. Only 17.2% of young adults aged 18 years old to 24 years old were dengue IgG positive. Multivariate analyses showed that older age, Indian ethnicity and male gender were significantly associated with past infection, whereas only age was significantly associated with recent dengue infection. Based on the dengue cases notified during the period of survey, it was estimated that for every 23 individuals recently infected with dengue, only 1 was reported to the health authority as a clinical case. CONCLUSION: The Singapore population is highly susceptible to dengue epidemics despite its aggressive Aedes prevention and control programme. The finding of a high proportion of unreported cases due to asymptomatic and subclinical infection poses a challenge for dengue control.

Where the elderly die: the influence of socio-demographic factors and cause of death on people dying at home.

INTRODUCTION: The place of death of the elderly has implications on the overall healthcare delivery system. The aim of this study is to describe where deaths of elderly occur in Singapore and to determine the association of socio-demographic characteristics and the causes of death on dying at home. MATERIALS AND METHODS: Data of 10,399 Singapore resident decedents aged 65 years and above in 2006 were obtained from the national Registry of Births and Deaths. Distributions of socio-demographic characteristics and causes of death by place of death were analysed, and associations between socio-demographic characteristics and home death for major causes of death were assessed by logistic regression models controlling for age, gender and ethnic group. RESULTS: Most elderly deaths occurred in hospitals (57%), followed by deaths at home (31%). The proportion of deaths at home increased with age while deaths in hospital declined with age. Significantly more elderly women died at home compared to men. Malay elderly had the highest proportion of home deaths (49%), and the lowest proportion of hospital deaths (47%). Elderly persons who died from stroke were most likely to die at home [odds ratio (OR) 2.8, 95% confidence interval (CI), 2.3-3.3] while those who died from lung and respiratory system diseases were less likely to die at home (OR, 0.7; 95% CI, 0.6-0.8). CONCLUSION: Elderly people in Singapore die mainly in hospitals. About a third of them die at home. The proportion of decedents dying at home increased with age. Home deaths among the elderly are most likely in those aged 85 years and above, females, Malays, and those who die of stroke.

A systematic review of the effectiveness of Tai Chi on fall reduction among the elderly.

Falls among the elderly is a major public health concern. There has been recent extensive research on the effects of Tai Chi in fall prevention among the elderly. As such, we undertook a systematic review to look for evidence on the effect of this intervention. There were seven randomized controlled trials, which met our objective and inclusion criteria. Our review has shown that Tai Chi has the potential to reduce falls or risk of falls among the elderly, provided that they are relatively young and non-frail. Further review is needed to look into the non-English studies, which assess the effectiveness of Tai Chi on fall reduction.

Influence of pre-hypertension on all-cause and cardiovascular mortality: the Singapore Cardiovascular Cohort Study.

BACKGROUND: The effect of "pre-hypertension" (pre-HTN) itself, and in combination with other cardiovascular disease (CVD) risk factors in relation to mortality has not been assessed in Asian populations. METHODS: From three cross-sectional studies conducted in Singapore (baseline 1982-1995), 5830 persons were grouped into normotensive (NT), pre-HTN or hypertensive (HTN). Follow-up (median 12.0 yrs, IQR 12-19 yrs) was done by linkage to the National Death Register. Outcomes included all-cause and CVD (ischaemic heart disease (ICD-9 410-414) and cerebrovascular accidents (ICD-9 430-438)). Cox's proportional hazards model was used to obtain adjusted hazard ratios (HRs) for risk of mortality. RESULTS: After adjustment, pre-HTN was not associated with a statistically significant increased risk of all-cause or CVD mortality. However, an increased risk for all-cause and CVD mortality, in the presence of diabetes (adjusted HR 1.8; 95%CI 1.0-2.9 and 4.4; 95%CI 1.9-10.4), smoking (adjusted HR 2.2; 95%CI 1.3-3.5 and 4.9; 95%CI 1.8-13.3), and especially, pre-existing CVD (adjusted HR 3.1; 95%CI 1.5-6.4 and 9.3; 95%CI 3.3-25.9) was found. CONCLUSIONS: Pre-HTN was not an independent risk factor for mortality. However an increased risk of mortality for pre-HTN in the presence of other CVD risk factors was observed. This finding supports current recommendations to screen for these risk factors in the pre-HTN Asian population.

A family history of type 2 diabetes is associated with glucose intolerance and obesity-related traits with evidence of excess maternal transmission for obesity-related traits in a South East Asian population.

AIM: To evaluate family history (FH) of type 2 diabetes (T2DM) as a risk factor for impaired fasting glucose (IFG), impaired glucose tolerance (IGT), T2DM and related metabolic traits in South East Asia and to compare the effects of a paternal versus maternal history. METHODS: We studied 4717 men and women (68% Chinese, 18% Malays and 14% Asian Indians) living in Singapore. FH was considered positive if at least one first degree relative had T2DM. Obesity, fasting lipids, glucose and insulin levels were measured for all subjects. Insulin resistance (IR) was estimated by homeostasis model assessment (HOMA). An oral glucose tolerance test was carried for all subjects except those on diabetes medication. RESULTS: A positive FH was associated with increased risk of IFG/IGT (OR=1.67, 95% CI=1.42-1.97) and T2DM (OR=2.95, 95% CI=2.36-3.70) as well as higher levels of obesity, HOMA-IR, fasting triglyceride (TG), and lower levels of high density lipoprotein (HDL) cholesterol and HOMA-beta. A maternal history of T2DM appeared to have a greater impact on obesity-related traits than a paternal history of T2DM. Compared to individuals with no FH of T2DM, a maternal history was associated with (i) greater body mass index (BMI) (24.15kg/m(2) vs. 23.42kg/m(2), p=0.016) and waist-to-hip ratio (WHR) (0.874 vs. 0.865, p=0.037) in men; and (ii) greater WHR (0.788 vs. 0.779, p=0.004), fasting triglyceride (1.23mmol/L vs. 1.09mmol/L, p<0.001), HOMA-IR (2.02 vs. 1.75, p<0.001), fasting plasma glucose (5.25mmol/L vs. 5.18mmol/L, p=0.005) and 2-h plasma glucose (6.01mmol/L vs. 5.78mmol/L, p=0.001) and lower HDL-C (1.41mmol/L vs. 1.47mmol/L, p=0.031) in women. CONCLUSION: T2DM appears to be heritable in South East Asians with excess maternal transmission of obesity, IR and dyslipidemia.

FTO variants are associated with obesity in the Chinese and Malay populations in Singapore.

OBJECTIVE: Association between genetic variants at the FTO locus and obesity has been consistently observed in populations of European ancestry and inconsistently in non-Europeans. The aim of this study was to examine the effects of FTO variants on obesity and type 2 diabetes in Southeast Asian populations. RESEARCH DESIGN AND METHODS: We examined associations between nine previously reported FTO single nucleotide polymorphisms (SNPs) with obesity, type 2 diabetes, and related traits in 4,298 participants (2,919 Chinese, 785 Malays, and 594 Asian Indians) from the 1998 Singapore National Health Survey (NHS98) and 2,996 Malays from the Singapore Malay Eye Study (SiMES). RESULTS: All nine SNPs exhibited strong linkage disequilibrium (r(2) = 0.6-0.99), and minor alleles were associated with obesity in the same direction as previous studies with effect sizes ranging from 0.42 to 0.68 kg/m(2) (P < 0.0001) in NHS98 Chinese, 0.65 to 0.91 kg/m(2) (P < 0.02) in NHS98 Malays, and 0.52 to 0.64 kg/m(2) (P < 0.0001) in SiMES Malays after adjustment for age, sex, smoking, alcohol consumption, and exercise. The variants were also associated with type 2 diabetes, though not after adjustment for BMI (with the exception of the SiMES Malays: odds ratio 1.17-1.22; P

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.

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.

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.

Trends in alcohol consumption in Singapore 1992 2004.

AIMS: To present trends in alcohol consumption between 1992 and 2004 in Singapore. METHODS: Alcohol consumption data were derived from national health surveys conducted in 1992, 1998 and 2004. Age-adjusted prevalence of frequent (drinking 1-4 days a week), regular (drinking more than 4 days a week) and binge (having five or more drinks during a drinking session at least once in the month) drinking by gender and age group for the three surveys were compared. Multivariate analyses for binge drinking in 2004 were performed using logistic regression models. RESULTS: Prevalence of frequent, regular and binge drinking increased between 1992 and 2004. Prevalence increase in binge drinking was highest (from 5.1 to 10.0%), followed by frequent drinking (from 4.5 to 7.5%) and regular drinking (from 2.9 to 3.1%). Uptake in binge drinking increased in both genders and across all age groups but was most evident among adults aged 18-29. Frequent drinking increase was observed for both genders but was most pronounced among women aged 18-29. The level of regular drinking declined in men but increased in women, especially those aged 18-29 and 30-49. Being younger, male, separated, divorced or widowed, a current smoker, or having a monthly household income of S$6000 and above were attributes positively associated with binge drinking. CONCLUSIONS: Alcohol consumption, especially binge drinking, has increased among Singaporeans between 1992 and 2004. There is gender convergence in alcohol consumption.

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.

The impact of central obesity as a prerequisite for the diagnosis of metabolic syndrome.

OBJECTIVE: To compare the prevalence of metabolic syndrome (MS) defined according to the American Heart Association (AHA)/National Heart Lung and Blood Institute (NHLBI) and the International Diabetes Federation (IDF) and to determine the effect of the presence of central obesity on the phenotype (insulin resistance and other cardiovascular risk factors) associated with MS. RESEARCH METHODS AND PROCEDURES: We studied 4723 Chinese, Malays, and Asian Indians living in Singapore. Each individual was categorized according to the five criteria for MS as defined by the AHA/NHLBI and the IDF. The population was categorized according to the presence of three or more criteria and then further subcategorized according to the presence or absence of central obesity. Characteristics of each group were compared using ANOVA and the chi2 test. RESULTS: MS was present in 20.2% (IDF) and 26.9% (AHA/NHLBI) of the population. Of the population, 6.7% exhibited three or more features of MS without central obesity. Use of the IDF definition, which requires central obesity, is associated with greater insulin resistance but similar levels of other cardiovascular disease risk factors than the use of the AHA/NHLBI definition, which does not require central obesity. DISCUSSION: In this Southeast Asian population, the IDF and the AHA/NHLBI definitions of MS identify different segments of the MS population. The IDF definition may be more appropriate for the identification of those with insulin resistance and increased risk of type 2 diabetes. In contrast, the AHA/NHLBI definition may better identify those at increased risk of cardiovascular disease.

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.