Cardiovascular diseases in Chinese, Malays, and Indians in Singapore. II. Differences in risk factor levels.

STUDY OBJECTIVE--The aim of the study was to examine cardiovascular risk factors to see how these might explain differences in cardiovascular disease mortality among Chinese, Malays, and Indians in the Republic of Singapore. DESIGN--The study was a population based cross sectional survey. Stratified systematic sampling of census districts, reticulated units, and houses was used. The proportions of Malay and Indian households were increased to improve statistical efficiency, since about 75% of the population is Chinese. SETTING--Subjects were recruited from all parts of the Republic of Singapore. SUBJECTS--2143 subjects aged 18 to 69 years were recruited (representing 60.3% of persons approached). There were no differences in response rate between the sexes and ethnic groups. MEASUREMENTS AND MAIN RESULTS--Data on cardiovascular risk factors were collected by questionnaire. Measurements were made of blood pressure, serum cholesterol, low and high density lipoprotein cholesterol, fasting triglycerides and plasma glucose. In males the age adjusted cigarette smoking rate was higher in Malays (53.3%) than in Chinese (37.4%) or Indians (44.5%). In both sexes, Malays had higher age adjusted mean systolic blood pressure: males 124.6 mm Hg v 121.2 mm Hg (Chinese) and 121.2 mm Hg (Indians); females 122.8 mm Hg v 117.3 mm Hg (Chinese) and 118.4 mm Hg (Indians). Serum cholesterol, low density lipoprotein cholesterol and triglyceride showed no ethnic differences. Mean high density lipoprotein cholesterol in males (age adjusted) was lower in Indians (0.69 mmol/litre) than in Chinese (0.87 mmol/litre) and Malays (0.82 mmol/litre); in females the mean value of 0.95 mmol/litre in Indians was lower than in Chinese (1.05 mmol/litre) and Malays (1.03 mmol/litre). Rank prevalence of diabetes for males was Indians (highest), Malays and then Chinese; for females it was Malays, Indians, Chinese. CONCLUSIONS--The higher mortality from ischaemic heart disease found in Indians in Singapore cannot be explained by the major risk factors of cigarette smoking, blood pressure and serum cholesterol; lower high density lipoprotein cholesterol and higher rates of diabetes may be part of the explanation. The higher systolic blood pressures in Malays may explain their higher hypertensive disease mortality.     

Seroprevalence of IgG antibodies against Chlamydia pneumoniae in Chinese,Malays and Asian Indians in Singapore

BACKGROUND: Chlamydia pneumoniae, a bacterium that causes respiratory infections, is probably under-diagnosed. There is also interest in its possible role in the aetiology of coronary heart disease. This is the first population-based seroprevalence survey of C. pneumoniae infection in Singapore. METHODS: A random sample of 1,068 people aged 18-69 years was selected from the participants of the Singapore National Health Survey conducted in 1998. Sera and data on certain clinical measurements and conditions had been collected. IgG antibodies for C. pneumoniae were detected using an indirect microimmunofluorescence test and positivity graded. Seropositivity was defined as IgG titre >/=1:16. RESULTS: There were no statistically significant differences in the prevalence rates of seropositivity to C. pneumoniae for age group 18-69 years among the three ethnic groups, i.e. Chinese (males 76.7%, females 68.3%), Malays (males 75.4%, females 59.1%), and Asian Indians (males 74.6%, females 59.4%). The seropositivity rate for people aged 18-69 years in Singapore was 75.0% for males and 65.5% for females (difference of 9.5%, P < 0.001). In both genders combined, seropositivity increased from 46.5% in the age group 18-29 to reach a plateau of 78.9% in the age group 40-49, which remained stable to 60-69 years. There was no association of seropositivity with smoking, diabetes mellitus, hypertension or body mass index after adjustment for age and gender. CONCLUSION: The high prevalence rates in our study population and the higher rate in males compared to females are consistent with studies from other parts of the world. No significant difference in prevalence rates was observed among Chinese, Malays and Indians. The pattern of rising and levelling off of seropositivity with age suggests that C. pneumoniae infection occurs early in life, and in older ages the high level of seropositivity is probably maintained by re-infections or chronic infections. Chlamydia pneumoniae infection was not found to be associated with the cardiovascular risk factors examined.     

Vitamins, selenium, iron, and coronary heart disease risk in Indians, Malays, and Chinese in Singapore

STUDY OBJECTIVE: To examine the hypothesis that the higher rates of coronary heart disease (CHD) in Indians (South Asians) compared with Malays and Chinese is partly because of differences in antioxidants (vitamins A, C, and E, and selenium) and pro-oxidants (iron). DESIGN: Cross sectional study of the general population. SETTING: Singapore. PARTICIPANTS: Random sample of 941 persons aged 30 to 69 years. MAIN RESULTS: There were moderate correlations between vitamin A and vitamin E, and between these vitamins and selenium. Mean plasma vitamins A and E were similar by ethnic group. Vitamin A concentration for Indians were (men 0.66 and women 0.51 mg/l), Malays (men 0.67 and women 0.54 mg/l), and Chinese (men 0.68 and women 0.52 mg/l). Vitamin E concentrations for Indians were (men 12.9 and women 12.8 mg/l), Malays (men 13.6 and women 13.3 mg/l), and Chinese (men 12.6 and women 12.6 mg/l). In contrast, mean plasma vitamin C concentrations were lower in Indians (men 5.7 and women 6.9 mg/l) and Malays (men 5.1 and women 6.4 mg/l) than Chinese (men 6.3 and women 8.4 mg/l). Mean serum selenium was lower in Indians (men 117 and women 115 micrograms/l) than Malays (men 122 and women 122 micrograms/l) and Chinese (men 126 and women 119 micrograms/l). Mean serum ferritin was much lower in Indians (men 132 and women 50 micrograms/l) than Malays (men 175 and women 85 micrograms/l) and Chinese (men 236 and women 92 micrograms/l). MAIN CONCLUSIONS: Lower vitamin C and selenium in Indians, particularly in combination, could play a part in their increased risk of CHD. Vitamins A and E, and ferritin (iron) have no such role. Lower vitamin C in Indians and Malays is probably because of its destruction by more prolonged cooking. In Indians, lower selenium is probably because of a lower dietary intake and the much lower ferritin to a lower dietary intake of iron and its binding by phytates.

 

     

Homocysteine, folate, vitamin B12, and cardiovascular risk in Indians, Malays, and Chinese in Singapore

OBJECTIVE: To examine the hypothesis that the higher rates of coronary heart disease (CHD) in Indians (South Asians) compared with Malays and Chinese is partly attributable to differences in blood concentrations of homocysteine, and related blood concentrations of folate and vitamin B12. DESIGN: Cross sectional study of the general population. SETTING: Singapore. PARTICIPANTS: Random sample of 726 fasting subjects aged 30 to 69 years. MAIN RESULTS: Mean plasma total homocysteine concentrations did not show significant ethnic differences; values were Indians (men 16.2 and women 11.5 mumol/l), Malays (men 15.0 and women 12.5 mumol/l), and Chinese (men 15.3 and women 12.2 mumol/l). Similarly, the proportions with high plasma homocysteine (> 14.0 mumol/l) showed no important ethnic differences being, Indians (men 60.0 and women 21.9%), Malays (men 53.9 and women 37.8%), and Chinese (men 56.6 and women 30.6%). Mean plasma folate concentrations were lower in Indians (men 8.7 and women 10.9 nmol/l) and Malays (men 8.5 and women 10.8 nmol/l), than Chinese (men 9.7 and women 13.8 nmol/l). Similarly, the proportions with low plasma folate (< 6.8 nmol/l) were higher in Indians (men 44.9 and women 36.6%) and Malays (men 45.3 and women 24.5%) than Chinese (men 31.4 and women 12.6%). Mean plasma vitamin B12 concentrations were lowest in Indians (men 352.5 and women 350.7 pmol/l), then Chinese (men 371.1 and women 373.7 pmol/l), and then Malays (men 430.5 and women 486.0 pmol/l). CONCLUSION: While there were ethnic differences for plasma folate and vitamin B12 (in particular lower levels in Indians), there was no evidence that homocysteine plays any part in the differential ethnic risk from CHD in Singapore and in particular the increased susceptibility of Indians to the disease.     

Central obesity, insulin resistance, syndrome X, lipoprotein(a), and cardiovascular risk in Indians, Malays, and Chinese in Singapore.

STUDY OBJECTIVE: To examine the hypothesis that the higher rates of coronary heart disease (CHD) in Indians (South Asians) compared with Malays and Chinese is at least partly explained by central obesity, insulin resistance, and syndrome X (including possible components). DESIGN: Cross sectional study of the general population. SETTING: Singapore. PARTICIPANTS: Random sample of 961 men and women (Indians, Malays, and Chinese) aged 30 to 69 years. MAIN RESULTS: Fasting serum insulin concentration was correlated directly and strongly with body mass index (BMI), waist-hip ratio (WHR), and abdominal diameter. The fasting insulin concentration was correlated inversely with HDL cholesterol and directly with the fasting triglyceride concentration, blood pressures, plasminogen activator inhibitor 1 (PAI-1), and tissue plasminogen activator (tPA), but it was not correlated with LDL cholesterol, apolipoproteins B and A1, lipoprotein(a), (Lp(a)), fibrinogen, factor VIIc, or prothrombin fragment (F)1 + 2. This indicates that the former but not the latter are part of syndrome X. While Malays had the highest BMI, Indians had a higher WHR (men 0.93 and women 0.84) than Malays (men 0.91 and women 0.82) and Chinese (men 0.91 and women 0.82). In addition, Indians had higher fasting insulin values and more glucose intolerance than Malays and Chinese. Indians had lower HDL cholesterol, and higher PAI-1, tPA, and Lp(a), but not higher LDL cholesterol, fasting triglyceride, blood pressures, fibrinogen, factor VIIc, or prothrombin F1 + 2. CONCLUSIONS: Indians are more prone than Malays or Chinese to central obesity with insulin resistance and glucose intolerance and there are no apparent environmental reasons for this in Singapore. As a consequence, Indians develop some but not all of the features of syndrome X. They also have higher Lp(a) values. All this puts Indians at increased risk of atherosclerosis and thrombosis and must be at least part of the explanation for their higher rates of CHD.     

Incense Use and Cardiovascular Mortality among Chinese in Singapore: The Singapore Chinese Health Study

Background: Incense burning is common in many parts of the world. Although it is perceived that particulate matter from incense smoke is deleterious to health, there is no epidemiologic evidence linking domestic exposure to cardiovascular mortality.Objective: We examined the association between exposure to incense burning and cardiovascular mortality in the Singapore Chinese Health Study.Methods: We enrolled a total of 63,257 Singapore Chinese 45–74 years of age during 1993–1998. All participants were interviewed in person to collect information about lifestyle behaviors, including the practice of burning incense at home. We identified cardiovascular deaths via record linkage with the nationwide death registry through 31 December 2011.Results: In this cohort, 76.9% were current incense users, and most of the current users (89.9%) had burned incense daily for ≥ 20 years. Relative to noncurrent users, current users had a 12% higher risk of cardiovascular mortality [multivariable adjusted hazard ratio (HR) = 1.12; 95% CI: 1.04, 1.20]. The HR was 1.19 (95% CI: 1.03, 1.37) for mortality due to stroke and 1.10 (95% CI: 1.00, 1.21) for mortality due to coronary heart disease. The association between current incense use and cardiovascular mortality appeared to be limited to participants without a history of cardiovascular disease at baseline (HR = 1.16; 95% CI: 1.07, 1.26) but not linked to those with a history (HR = 1.00; 95% CI: 0.86, 1.17). In addition, the association was stronger in never-smokers (HR = 1.12; 95% CI: 1.02, 1.23) and former smokers (HR = 1.19; 95% CI: 1.00, 1.42) than in current smokers (HR = 1.05; 95% CI: 0.91, 1.22).Conclusions: Long-term exposure to incense burning in the home environment was associated with an increased risk of cardiovascular mortality in the study population.Citation: Pan A, Clark ML, Ang LW, Yu MC, Yuan JM, Koh WP. 2014. Incense use and cardiovascular mortality among Chinese in Singapore: The Singapore Chinese Health Study. Environ Health Perspect 122:1279–1284; http://dx.doi.org/10.1289/ehp.1307662     

Differences in body composition between Singapore Chinese,Beijing Chinese and Dutch children

OBJECTIVES: To compare the relationship between body mass index (BMI) and body fat percentage (BF%) in children of different ethnic background. DESIGN: Cross-sectional observational study. SETTINGS: The study was performed in three different locations, Singapore, Beijing and Wageningen (The Netherlands). SUBJECTS: In each centre 25 boys and 25 girls, aged 7-12 y, were selected. They were matched on age, sex and body height. METHODS: Body weight and body height was measured following standardized procedures. The body mass index (BMI) was calculated as weight/height squared (kg/m(2)). Body fat was measured by densitometry in Beijing and Wageningen and by dual energy X-ray absorptiometry (DXA) in Singapore. The DXA measurements in Singapore were validated against densitometry. RESULTS: There were no significant differences in BF% or BMI within each gender group across the three study sites. However, after controlling for (non-significant) differences in age and BF%, the Singapore children had a lower (mean+/-s.e.) BMI (15.6+/-0.3) than the Beijing 17.6+/-0.3) and Wageningen (16.9+/-0.3) children. For the same BMI, age and sex the Singapore children had a significant higher BF% (24.6+/-0.7) than the Beijing (19.2+/-0.8) and Wageningen (20.3+/-0.7) children. CONCLUSIONS: The study strongly suggests that the relationship between BF% and BMI (or weight and height) is different among children of different ethnic background. Consequently growth charts and BMI cut-off points for underweight, overweight and obesity in children may have to be ethnic-specific.     

Differences in cause-specific infant mortality among Chinese, Japanese, and white Americans.

Although black-white differences in infant mortality have received much attention, information is limited about mortality differentials among Asian Americans. This study investigated racial differences in infant mortality in a sample of 21,288 Chinese, 11,882 Japanese, and 65,818 white resident singleton livebirths obtained from the National Center for Health Statistics 1983 and 1984 linked birth/infant death files. The crude infant mortality rates were 8.03, 6.56, and 8.46 per 1,000 livebirths for Chinese, Japanese, and white births, respectively. Cause-specific mortality varied considerably among the three racial groups. While the Japanese had lower rates of infant deaths and deaths from perinatal conditions for firstborn infants, they had higher rates of sudden infant death syndrome, as did Chinese females. The results of a logistic regression analysis indicate that the racial differences in total and cause-specific mortality persist when adjustment is made for demographic factors, use of prenatal care, infant sex, and birth weight. The effect of these latter variables on infant mortality varied by causes of death. The relations between infant mortality and variables such as marital status, maternal education, and birth interval appear indirect, operating partially through birth weight. While birth weight was the single strongest determinant of infant mortality, its relative importance varied by cause of death. The study findings suggest that policy decisions surrounding racial differences in infant mortality should not only be considered in light of specific races, but also with regard to cause-specific mortality. Moreover, additional research is needed to understand the cultural, biological, and behavioral factors that give rise to the racial differences.     

Trends in mortality from hypertensive and cerebrovascular diseases in Singapore, 1959 to 1983

Secular trends in mortality from hypertensive and cerebrovascular diseases have been studied in Singapore from vital statistics for the years from 1959 to 1983. Males were found to have higher mortality than females from hypertensive disease (by about 25%) and cerebrovascular disease (by about 20%). After an initial slight rise mortality from hypertensive disease fell markedly from the mid-1960s (slightly more in males than females) but the rate of decline has levelled off in the last few years. A more modest decline in cerebrovascular disease mortality started in the early 1970s in males and the mid-1970s in females, with the decline to date being slightly more in males. These declines started at the same point in time in both sexes and in all age groups, with the rate of decline falling with age. The timing and patterns of these declines are consistent with the theory that treatment of hypertension has played a significant role.     

Ethnic differences in quality of life in adolescents among Chinese,Malay and Indians in Singapore

Background: Health-related quality of life in adolescents and ethnic and cultural differences are not well characterized. We used the Quality of Life Questionnaire for Adolescents (QOLQA) to examine ethnic differences in reported QOL scores among Chinese, Malay and Indian ethnicities in Singapore. Methods: The 70-item QOLQA measuring five QOL domains (physical, psychological, independence, social and environmental) was administered to a random sample of 1363 school-children aged 10–15 years, representative of the ethnic composition of Singapore adolescents (Chinese 72%, Malays 20% and Indians 8%). Results: Indians reported the highest overall QOL (mean 3.71 ± SD 0.54) compared to Chinese (3.59 ± 0.43), p <0.05, and Malays (3.58 ± 0.44), p < 0.05. In particular, Indians had significantly higher psychological QOL scores (3.73 ± 0.61) compared to Chinese (3.55 ± 0.54), p < 0.01. On the other hand, Chinese scored highest on physical and independence domains (3.97 ± 0.54), p < 0.01 compared to Malays (3.82 ± 0.55). There were no statistically significant gender differences in QOL scores. QOL declined significantly from age 10 to 15 for overall score, psychological, physical (p < 0.01) and environmental (p < 0.05). Lower socio-economic status and the self-report of a significant health problem were significantly associated with lower overall QOL and most domains. These ethnic differences persisted after adjusting for differences in socio-economic and health status. Psychometric properties and known group construct validity appeared to be similar across different ethnic groups, but compared to Chinese (r = 0.39) or Malays (r = 0.39), Indians showed a higher correlation of psychological scores with physical score (r = 0.59) and with other domain scores. Conclusion: Significant ethnic differences in reported adolescent quality of life among Chinese, Malays and Indians in Singapore that are independent of socio-economic and health status suggest important cultural differences.     

Differences in all-cause, cardiovascular and cancer mortality between Hong Kong and Singapore: Role of nutrition

BACKGROUND: The majority of inhabitants in Hong Kong and Singapore are ethnic Chinese, but all-cause and cardiovascular mortality rates in these two regions are markedly different. This study describes differences in the magnitude and trends in mortality and attempts to explain these differences. METHODS: Data of mortality rates in 1963-1965 and 1993-1995 in the age class of 45-74 years, dietary habits and other factors were compared between Hong Kong and Singapore using Japan, Spain and the USA as reference countries. Mortality and food consumption data were obtained from WHO and FAO, respectively. RESULTS: Large differences in all-cause and cardiovascular mortality exist between Hong Kong and Singapore. The difference in total cancer mortality was less consistent and smaller. The most pronounced finding was that ischemic heart disease mortality in 1993-1995 was 2.98 and 3.14 times higher in Singapore than in Hong Kong in men and women, respectively. Of the five countries considered, Singapore has the highest all-cause mortality in both sexes in the period of 1960-1995. The ratio of animal to vegetal fat was higher in Singapore (2.24) than in Hong Kong (1.08). Singapore had higher serum concentrations of total cholesterol and low-density lipoprotein cholesterol than Hong Kong, but the opposite result was observed for high-density lipoprotein cholesterol. CONCLUSIONS: There are striking differences in all-cause and cardiovascular mortality between Hong Kong and Singapore. These differences can be most reasonably and plausibly explained by their differences in dietary habits, for example, a higher consumption of coconut and palm oil, mainly containing saturated fat, in Singapore.     

Cardiovascular mortality of Chinese in New York City

To determine cardiovascular disease mortality among Chinese migrants in New York City and compare it to both that of residents in China and whites in New York City, mortality records for 1988 through 1992 for New York City and the 1990 US census data for New York City were linked. Age-specific death rates for urban China, reported by the World Health Organization, were used for comparison. The results show that male and female Chinese residents in New York City had lower mortality rates for all causes and total cardiovascular disease than did either New York City whites or Chinese in China. Coronary heart disease deaths among New York City Chinese were intermediate between Chinese in China (lowest) and New York City whites (highest). Stroke death rates for New York City Chinese were substantially lower than those in China and, in general, were similar to those for New York City whites. However, New York City Chinese had higher death rates for hemorrhagic stroke and lower for atherosclerotic stroke than did New York City whites. In conclusion, cardiovascular mortality rates among Chinese migrants in New York City fall below those of both Chinese in China and whites in New York City.     

Body fat measurement among Singaporean Chinese, Malays and Indians: a comparative study using a four-compartment model and different two-compartment models

This cross-sectional study compared body fat percentage (BF%) obtained from a four-compartment (4C) model with BF% from hydrometry (using 2H2O), dual-energy X-ray absorptiometry (DXA) and densitometry among the three main ethnic groups (Chinese, Malays and Indians) in Singapore, and determined the suitability of two-compartment (2C) models as surrogate methods for assessing BF% among different ethnic groups. A total of 291 subjects (108 Chinese, seventy-six Malays, 107 Indians) were selected to ensure an adequate representation of age range (18-75 years) and BMI range (16-40 kg/m2) of the general adult population, with almost equal numbers from each gender group. Body weight was measured, together with body height, total body water by 2H2O dilution, densitometry with Bodpod and bone mineral content with Hologic QDR-4500. BF% measurements with a 4C model for the subgroups were: Chinese females 33.5 (sd 7.5), Chinese males 24.4 (sd 6.1), Malay females 37.8 (sd 6.3), Malay males 26.0 (sd 7.6), Indian females 38.2 (sd 7.0), Indian males 28.1 (sd 5.5). Differences between BF% measured by the 4C and 2C models (hydrometry, DXA and densitometry) were found, with underestimation of BF% in all the ethnic-gender groups by DXA of 2.1-4.2 BF% and by densitometry of 0.5-3.2 BF%). On a group level, the differences in BF% between the 4C model and 2H2O were the lowest (0.0-1.4 BF% in the different groups), while differences between the 4C model and DXA were the highest. Differences between the 4C model and 2H2O and between the 4C model and DXA were positively correlated with the 4C model, water fraction (f(water)) of fat-free mass (FFM) and the mineral fraction (f(mineral)) of FFM, and negatively correlated with density of the FFM (D(FFM)), while the difference between 4C model and densitometry correlated with these variables negatively and positively respectively (i.e. the correlations were opposite). The largest contributors to the observed differences were f(water) and D(FFM). When validated against the reference 4C model, 2C models were found to be unsuitable for accurate measurements of BF% at the individual level, owing to the high errors and violation of assumptions of constant hydration of FFM and D(FFM) among the ethnic groups. On a group level, the best 2C model for measuring BF% among Singaporeans was found to be 2H2O.     

Cardiovascular diseases and diabetes mellitus in Fiji: analysis of mortality, morbidity and risk factors

Mortality and hospital admissions due to cardiovascular diseases and diabetes mellitus have been increasing in Fiji steadily over the past 20 years. These diseases were present more frequently in the Indian than the Melanesian population of Fiji, but recently the steepest rise in prevalence rates occurred among the Melanesian population. The underlying conditions that contributed most to increasing mortality and morbidity were hypertension and diabetes mellitus. In 1978, the proportional mortality from diabetes mellitus was 6.0% (9.0% in persons aged ≥ 40 years), and that from cardiovascular diseases was 30.3% (39% in those aged ≥ 40 years). Ischaemic heart disease was the main cause of mortality and morbidity among the Indian population. This analysis of mortality and morbidity data is supported by the findings of a population survey, which showed that the prevalence rates of diabetes and hypertension in 1980 among urban Melanesians were similar to those among Indians. Urbanization and a modern life-style seem to play an important role in determining the disease pattern in Fiji, which is following the patterns in many industrial countries.     

Cardiovascular disease in Navajo Indians with type 2 diabetes.

Rates of both type 2 diabetes and cardiovascular disease have risen sharply in recent years among Navajo Indians, the largest reservation-based American Indian tribe, but the association between the two conditions is not entirely clear. Rates of cardiovascular disease and some possible associations in several hundred diabetic and non-diabetic Navajos were estimated. Nearly one-third (30.9 percent) of those with diabetes had formal diagnoses of cardiovascular disease--25.3 percent had heart disease, 4.4 percent had cerebrovascular disease, and 4.1 percent had peripheral vascular disease. (The percentages exceed the total because some people had more than one diagnosis. Age-adjusted rates were 5.2 times those of nondiabetics for heart disease, 10.2 times for cerebrovascular disease, and 6.8 times for peripheral vascular disease. Accentuation of risk was most marked in young diabetics and in female diabetics. Hypertensive diabetics had a twofold increase in heart disease and more than a fivefold increase in cerebral and peripheral vascular disease over nonhypertensive diabetics. Age, blood pressure, cholesterol levels, and albumenuria were independent risk factors for cardiovascular disease. Triglyceride levels or body weight were not. Male sex and diabetes duration were independent risk factors for cerebral and peripheral vascular disease but not for heart disease. In view of the impressive segregation of cardiovascular disease in the diabetic Navajo population, the prevention of diabetes through population-based health promotion seems basic to its containment. Over the short term, vigorous treatment of hypertension in subjects who are already diabetic is mandatory.     

Respiratory disease mortality in New Mexico's American Indians and Hispanics.

To determine the effect of ethnic group on respiratory disease occurrence, average annual sex, ethnic, and disease specific mortality rates for the period of 1969 to 1977 were calculated for New Mexico's American Indian, Hispanic, and Anglo populations. Incidence data were available for respiratory tract cancer. This study corroborates previous findings of reduced mortality from lung cancer in American Indians of both sexes and in Hispanic males. American Indian mortality from tuberculosis and from influenza and pneumonia was high. Hispanic males and American Indians of both sexes showed low mortality rates for chronic obstructive pulmonary disease (COPD). Differing cigarette usage is the most obvious explanation for the variations in COPD and lung cancer occurrence with ethnic group.     

Cardiovascular risk factors. I. Review of possible causes of heart and vascular diseases

Despite the decline in the past 30 years in age-adjusted mortality, cardiovascular disease is still the most important cause of morbidity and mortality in the Western world and increasingly so in the non-Western world. The decreased mortality rate is attributed to increased knowledge of the risk factors, a concomitant healthier life style and improved treatment for the risk factors. It has been clearly demonstrated that increased serum levels of cholesterol, increased blood pressure, the presence of diabetes, physical inactivity and smoking increase the risk of cardiovascular disease. The role of estrogens, homocysteine, thrombotic and inflammatory factors is currently the subject of considerable research. It seems likely that a certain genetic constitution enhances the susceptibility to the effects of other risk factors. New candidate genes are being suggested daily. Until now, no clearly decisive results have been achieved in determining the relations between the investigated genetic polymorphisms and the occurrence of cardiovascular disease. The consumption of foodstuffs that are rich in anti-oxidants seems to reduce the risk of cardiovascular disease, but randomised research into the effects of anti-oxidants as food supplements suggests that this does not affect the development of cardiovascular disease.     

Risk factors and incident coronary heart disease in Chinese, Malay and Asian Indian males: the Singapore Cardiovascular Cohort Study.

OBJECTIVE: This prospective study in Singapore investigated the relationships of established coronary risk factors with incident coronary heart disease (CHD) for Chinese, Malay, and Asian Indian males. SUBJECTS: A cohort (consisting of 2879 males without diagnosed CHD) derived from three previous cross-sectional surveys. METHODS: Individual baseline data were linked to registry databases to obtain the first event of CHD. Hazard ratios (HR) or relative risks for risk factors were calculated using Cox's proportional hazards model with adjustment for age and ethnic group and adjustment for age, ethnic group and all other risk factors (overall adjusted). RESULTS: There were 24,986 person-years of follow-up. The overall adjusted HR with 95% CI are presented here. Asian Indians were at greatest risk of CHD, compared to Chinese (3.0; 2.0-4.8) and Malays (3.4; 1.9-3.3). Individuals with hypertension (2.4; 1.6-2.7) or diabetes (1.7; 1.1-2.7) showed a higher risk of CHD. High low density lipoprotein cholesterol (LDL-C) (1.5; 1.0-2.1), high fasting triglyceride (1.5; 0.9-2.6) and low high density lipoprotein cholesterol (HDL-C) (1.3; 0.9-2.0) showed a lesser but still increased risk. Alcohol intake was protective with non-drinkers having an increased risk of CHD (1.8; 1.0-3.3). Obesity (body mass index > or =30) showed an increased risk (1.8; 0.6-5.4). An increased risk of CHD was found in cigarette smokers of > or =20 pack years (1.5; 0.9-2.5) but not with lesser amounts. CONCLUSIONS: The increased susceptibility of Asian Indian males to CHD has been confirmed in a longitudinal study. All of the examined established risk factors for CHD were found to play important but varying roles in the ethnic groups in Singapore.