Risk factors for acute myocardial infarction in a southern Chinese population

Childhood food insufficiency and adulthood cardiometabolic health conditions among a population-based sample of older adults in Puerto Rico

Childhood food insufficiency negatively influences physical and psychosocial health in children, but less is known about long-term health implications. This study aimed to elucidate the association of childhood food insufficiency with older adulthood cardiometabolic conditions. We conducted cross-sectional analyses using data from the Puerto Rican Elderly: Health Conditions Project (n = 2712), a population-based sample of elderly adults (>60 y) living in Puerto Rico. Childhood food insufficiency was ascertained with a proxy question on childhood economic hardships that prevented eating. Participants self-reported hypertension, diabetes, and cardiovascular disease (CVD; including heart attack, heart disease, or stroke). Obesity was assessed as body mass index using measured height and weight. Multivariable-adjusted, sex-stratified, complex survey logistic regression models tested associations of childhood food insufficiency with each condition, number of cardiometabolic conditions (0-6), and age of onset. Nearly a third (29.4%) of the sample reported childhood food insufficiency; 68.7% reported hypertension, 29.6% reported type 2 diabetes, 34.2% reported CVD, 29.9% were categorized with obesity, and 55.4% had two or more cardiometabolic conditions. In men, but not women, childhood food insufficiency was associated with higher odds of hypertension (Odds Ratio (OR) (95% Confidence Intervals (CI)): 1.7 (1.1, 2.7)), CVD (1.7 (1.1, 2.6)), and having two (1.9 (1.0, 3.4) or three to four (2.3 (1.2, 4.4)) cardiometabolic conditions. Childhood food insufficiency was marginally associated with higher odds of early age of onset of CVD among men (2.2 (1.0, 4.7)). Childhood food insufficiency may increase the likelihood of having cardiometabolic conditions in Puerto Rican older men. Programs that enable access to sufficient, healthy food in childhood may help prevent eventual cardiovascular-related diseases.

The LRP6 rs2302685 polymorphism is associated with increased risk of myocardial infarction

Background

Abnormal lipids is one of the critical risk factors for myocardial infarction (MI), however the role of genetic variants in lipid metabolism-related genes on MI pathogenesis still requires further investigation. We herein genotyped three SNPs (LRP6 rs2302685, LDLRAP1 rs6687605, SOAT1 rs13306731) in lipid metabolism-related genes, aimed to shed light on the influence of these SNPs on individual susceptibility to MI.

Methods

Genotyping of the three SNPs (rs2302685, rs6687605 and rs13306731) was performed in 285 MI cases and 650 control subjects using polymerase chain reaction–ligation detection reaction (PCR–LDR) method. The association of these SNPs with MI and lipid profiles was performed with SPSS software.

Results

Multivariate logistic regression analysis showed that C allele (OR = 1.62, P = 0.039) and the combined CT/CC genotype (OR = 1.67, P = 0.035) of LRP6 rs2302685 were associated with increased MI risk, while the other two SNPs had no significant effect. Further stratified analysis uncovered a more evident association with MI risk among younger subjects (≤60 years old). Fascinatingly, CT/CC genotype of rs2302685 conferred increased LDL-C levels compared to TT genotype (3.0 mmol/L vs 2.72 mmol/L) in younger subjects.

Conclusions

Our data provides the first evidence that LRP6 rs2302685 polymorphism is associated with an increased risk of MI in Chinese subjects, and the association is more evident among younger individuals, which probably due to the elevated LDL-C levels.

Coronary artery disease risk factors in urban areas of Yazd City, Iran

BACKGROUND

Coronary artery disease (CAD) is a major cause of mortality and morbidity with high health care cost in both developed and developing countries. CAD accounts for nearly 50% of all yearly deaths in Iran.

OBJECTIVE

The aim of this study is to explore the main CAD risk factors in the urban areas of Yazd in the Islamic Republic of Iran.

METHODS

A hospital-based case-control study was conducted to investigate the role of the important CAD risk factors in urban area of Yazd city from December 2007 to June 2008. A total of 436 subjects in the age group of 30 to 75 years (218 cases and 218 controls) were included in this study. The tools of enquiry were a pretested and precoded questionnaire, physical examination, and laboratory findings. A confidence level of 95% and study power of 80% were considered for the interpretation of possible significant findings. Gender-wise stratified analysis was separately done for men and women using multiple conditional logistic regression.

RESULTS

A total of 75.5% of the participants were men and 24.5% were women. Five variables, including unskilled jobs, physical inactivity, giving positive history of hypertension, high levels of waist/hip ratio, and low levels of high-density lipoprotein (HDL) were the factors that could account for significant predictors of CAD in males on the logistic model (P < .05). No such significant CAD predictors were found for women.

CONCLUSION

The findings showed that categories of nonprofessional, physical inactivity, positive history of hypertension, wais/hip ratio ≥0.9 and HDL levels ≤40 mg/dL are the significant risk factors that can predict CAD in male residents of Yazd.

Alcohol consumption and risk of coronary heart disease among Chinese men

BACKGROUND

Observational studies suggest that moderate alcohol consumption may lower risk of myocardial infarction (MI) and coronary heart disease (CHD); yet, evidence for this comes almost entirely from Western populations.

METHODS

We conducted a prospective cohort study in 64,597 Chinese men aged > or = 40 years who were free of clinical CHD at baseline examination. Data on frequency and type of alcohol consumed were collected at the baseline examination in 1991 using a standard protocol. Follow-up evaluation was conducted in 1999-2000, with a response rate of 94%.

RESULTS

Over 494,084 person-years of follow-up, we documented 725 (361 fatal) incident MI and 976 (588 fatal) incident CHD events. After stratification by province to account for multi-stage sampling design and adjustment for age, education, physical activity, cigarette smoking, body mass index, systolic blood pressure, urbanization (urban vs. rural), geographic variation (north vs. south) and history of diabetes, relative risk (95% confidence interval) of MI was 0.93 (0.70-1.24) for participants consuming 1 to 6 drinks/week, 0.66 (0.54-0.82) for those consuming 7 to 34 drinks/week, and 0.58 (0.41-0.81) for those consuming > or = 35 drinks/week (p for linear trend <0.0001) compared to non-drinkers. The corresponding relative risks for CHD events were 0.99 (0.77-1.27), 0.67 (0.56-0.81), and 0.58 (0.44-0.78), respectively (p for linear trend <0.0001).

CONCLUSION

Alcohol consumption may be related to lower risk of MI and CHD in middle-aged and older Chinese men. However, heavy alcohol consumption may lead to increased mortality from other causes; therefore, the implications of these findings should be interpreted cautiously.

Prevalence and Impact of Diabetes Mellitus in Patients With Acute Myocardial Infarction: A 10-year Experience

Background: Diabetes mellitus is associated with a higher incidence of acute myocardial infarction. Objective: To study the prevalence and outcome of patients with diabetes among patients with acute myocardial infarction. Methods: Retrospectively, patients who presented with acute myocardial infarction in a 10-year period were identified from the coronary care unit database. Results: A total of 1598 Qatari patients were admitted with acute myocardial infarction, 863 (54%) of them had diabetes mellitus (females 68.5% vs males 48.3%; P < .001). In-hospital mortality rate was non-significantly higher in diabetic patients (18% vs 15% P = .15). Aspirin (odds ratio 2.39, 95% confidence interval 1.96-2.90, P = .003] and β-blocker use (odds ratio 1.75, 95% CI 1.21-2.52, P = .0001) were independently associated with reduced mortality risk. Conclusions: The prevalence of diabetes mellitus among patients with acute myocardial infarction in a geographically defined population in the developing world is high with a trend for poor outcomes. However, mortality was not significantly higher in diabetes mellitus than non-diabetes mellitus patients.

Growth environment and sex differences in lipids, body shape and diabetes risk

Background

Sex differences in lipids and body shape, but not diabetes, increase at puberty. Hong Kong Chinese are mainly first or second generation migrants from China, who have shared an economically developed environment for years, but grew up in very different environments in Hong Kong or contemporaneously undeveloped Guangdong, China. We assessed if environment during growth had sex-specific associations with lipids and body shape, but not diabetes.

Methodology and Principal Findings

We used multivariable regression in a population-based cross-sectional study, undertaken from 1994 to 1996, of 2537 Hong Kong Chinese residents aged 25 to 74 years with clinical measurements of ischaemic heart disease (IHD) risk, including HDL-cholesterol, ApoB, diabetes and obesity. Waist-hip ratio was higher (mean difference 0.01, 95% CI 0.001 to 0.02) in men, who had grown up in an economically developed rather than undeveloped environment, as was apolipoprotein B (0.05 g/L, 95% CI 0.001 to 0.10), adjusted for age, socio-economic status and lifestyle. In contrast, the same comparison was associated in women with lower waist-hip ratio (−0.01, 95% CI −0.001 to −0.02) and higher HDL-cholesterol (0.05 mmol/L, 95% CI 0.0004 to 0.10). The associations in men and women were significantly different (p-values<0.001). There were no such differences for diabetes.

Conclusions

Growth in a developed environment with improved nutrition may promote higher sex-steroids at puberty producing an atherogenic lipid profile and male fat pattern in men but the opposite in women, with tracking of increased male IHD risk into adult life.

Systematic Review of the Influence of Childhood Socioeconomic Circumstances on Risk for Cardiovascular Disease in Adulthood

PURPOSE

Adverse socioeconomic circumstances in childhood may confer a greater risk for adult cardiovascular disease (CVD). The purpose of this review is to systematically evaluate evidence for an association between socioeconomic circumstances during childhood and specific CVD subtypes, independent of adult socioeconomic conditions.

METHODS

We systematically retrieved individual-level studies of morbidity and mortality from CVD and specific CVD subtypes linked to early life influences, including coronary heart disease (CHD), ischemic and hemorrhagic stroke, peripheral vascular disease, markers of atherosclerosis (carotid intima-media thickness and stenosis), and rheumatic heart disease. Indicators of socioeconomic position in childhood varied, although most studies relied on father's occupation.

RESULTS

We located 40 studies (24 prospective, 11 case-control, and 5 cross-sectional) reported in 50 publications. Thirty-one studies (19 prospective, 7 case-control, and all 5 cross-sectional) found a robust inverse association between childhood circumstances and CVD risk, although findings sometimes varied among specific outcomes, socioeconomic measures, and sex. Case-control studies reported mixed results. The association was stronger for stroke and, in particular, hemorrhagic stroke, than for CHD. Childhood socioeconomic conditions remained important predictors of CVD, even in younger cohorts.

CONCLUSION

Childhood and adulthood socioeconomic circumstances are important determinants of CVD risk. The specific contribution of childhood and adulthood characteristics varies across different CVD subtypes. Disease-specific mechanisms are likely to explain the childhood origins of these adult health inequalities.

Decreased insulin sensitivity is associated with the extent of coronary artery disease in patients with angina

BACKGROUND

Insulin resistance has been proposed as an important risk factor in the development of atherosclerosis.

AIM

To evaluate the association of insulin resistance and coronary atherosclerosis, we investigated the correlation between insulin sensitivity and the degree of coronary stenosis in patients with angina pectoris.

METHODS

The study population consisted of 74 subjects with angina (54 men and 20 women) aged from 31 to 73 years. Coronary angiograms were evaluated by three semiquantitative scoring systems (vessel score, stenosis score and extent score) to estimate the extent of focal and diffuse coronary artery disease (CAD). Insulin sensitivity (K(ITT)) was determined by the insulin tolerance test.

RESULTS

There were significant correlations existed between K(ITT) and all three coronary scores. Multivariate analysis revealed significant and independent correlations of all three coronary scores with K(ITT) (vessel score: beta = -0.349, p = 0.004; stenosis score: beta = -0.487, p < 0.001; extent score: beta = -0.481, p < 0.001), even in patients without diabetes mellitus (vessel score: beta = -0.387, p = 0.008; stenosis score: beta = -0.469, p < 0.001; extent score: beta = -0.559, p < 0.001). K(ITT) was significantly lower in patient with diffuse CAD than without diffuse CAD (2.13 +/- 0.66 vs. 2.57 +/- 0.79%/min, p < 0.05). However, K(ITT) was not different between patients with and without focal CAD.

CONCLUSIONS

Insulin sensitivity has statistically significant and independent associations with the extent of coronary stenosis. These results suggest that insulin resistance may play a major role in the development of diffuse coronary artery stenosis.

Leisure time physical activity and mortality in Hong Kong: case-control study of all adult deaths in 1998

PURPOSE

Physical activity is associated with longevity; however, whether these beneficial effects extend to Chinese populations is unclear. We examined the relationship between leisure time physical activity (LTPA) and mortality in Hong Kong.

METHODS

Using a case-control study, past (10 years prior) levels of LTPA were ascertained via proxy informants for 24,079 dead cases (81% of all registered deaths) and 13,054 live controls aged #10878;35 years and were analyzed by unmatched logistic regression to determine their association with all-cause and cause-specific mortality.

RESULTS

Compared with an exercise frequency of <1 episode per month, > or = 1 episode of LTPA per month was inversely associated with all-cause mortality [multivariable odds ratio (OR)=0.63, 95% confidence interval (CI), 0.59, 0.68 for males; OR=0.75, 95% CI, 0.70, 0.80 for females; adjusted for age, education, smoking status, alcohol consumption, and physical demand at work]. Each activity level above the reference level of <1 episode per month (i.e., 1 episode per month to 1-3 episodes per week, > or = 4 episodes per week) had approximately the same level of risk reduction and no dose-response gradient was observed. The inverse association was stronger for cardiovascular than cancer deaths, particularly in males and was strongest for respiratory mortality. One-fifth of all 31,349 registered deaths in those aged 35 years and over in Hong Kong in 1998 were attributable to physical inactivity.

CONCLUSION

The present data confirm and extend previous findings in Caucasian populations on the association between leisure time physical activity and longevity. The population attributable risk from physical inactivity exceeds that due to tobacco smoking in this Hong Kong Chinese population. We predict mainland China will witness a similarly large mortality burden as it undergoes further socioeconomic development in the next few decades.

Physical activity decreases cardiovascular disease risk in women: review and meta-analysis

OBJECTIVE

To review and quantify the dose-response relationship of physical activity (PA) in initially healthy women on cardiovascular disease (CVD) outcomes, especially coronary heart disease (CHD) and stroke, and to assess the minimum amount of PA to reduce CVD risk.

DATA SOURCES

Studies on PA and CVD were searched in MEDLINE (January 1966-March 2003) with additional manual searches.

DATA SELECTION

Studies were included if they (1) provided data on women; (2) assessed PA (exposure) as either a continuous variable or a categorical variable with three or more levels, and CVD (outcome); and (3) provided information on relative risks (RRs) and 95% confidence intervals.

DATA EXTRACTION

Studies were reviewed, abstracted, and rated for quality by each author.

DATA SYNTHESIS

Thirty articles met the inclusion criteria. When studies were combined according to relative PA levels, the RRs showed a dose-response relationship for CHD (RR=1 [reference], 0.78, 0.53, 0.61, respectively; p for trend was <0.0001 for studies with four PA levels, n =5); for stroke (RR=1 [reference], 0.73, 0.68, p for trend was <0.0001 for studies with three PA levels, n =7); and for overall CVD (RR=1 [reference], 0.82, 0.78, p for trend was <0.0001 for studies with three PA levels, n =6). When studies were combined by absolute walking amount, even 1 hour/week walk was associated with reduced risk of CVD outcome.

CONCLUSIONS

Physical activity was associated with reduced risk of CVD among women in a dose-response fashion. Inactive women would benefit by even slightly increasing their PA (e.g., walking 1 hour per week or possibly less) and even more from additional PA.

Global burden of cardiovascular diseases: Part II: variations in cardiovascular disease by specific ethnic groups and geographic regions and prevention strategies

This two-part article provides an overview of the global burden of atherothrombotic cardiovascular disease. Part I initially discusses the epidemiological transition which has resulted in a decrease in deaths in childhood due to infections, with a concomitant increase in cardiovascular and other chronic diseases; and then provides estimates of the burden of cardiovascular (CV) diseases with specific focus on the developing countries. Next, we summarize key information on risk factors for cardiovascular disease (CVD) and indicate that their importance may have been underestimated. Then, we describe overarching factors influencing variations in CVD by ethnicity and region and the influence of urbanization. Part II of this article describes the burden of CV disease by specific region or ethnic group, the risk factors of importance, and possible strategies for prevention.

The impact of heavy passive smoking on arterial endothelial function in modernized Chinese

OBJECTIVES

The study evaluated whether heavy exposure to environmental tobacco smoke (passive smoking) might damage arterial function in modernized Chinese.

BACKGROUND

Heavy passive smoking is associated with arterial endothelial dysfunction in Caucasian, but not rural Chinese, subjects.

METHODS

We studied 20 young (mean age 36.6 +/- 7.0 years) nonsmoking asymptomatic casino workers (9 men) in Macau who were exposed to environmental tobacco smoke for over 8 h/day for at least two years and 20 normal subjects (control subjects). These two groups were carefully matched for age, gender, body mass index (BMI), blood pressure, vessel diameter, cholesterol and glucose levels. Brachial artery diameter was measured by high-resolution B-mode ultrasound at rest, after flow increase (causing flow-mediated endothelium-dependent dilation) and after sublingual nitroglycerin (an endothelium-independent dilator).

RESULTS

Flow-mediated dilation (mean +/- SD% of diameter changes) was significantly lower in passive smokers (6.6 +/- 3.4%) compared with the controls (10.6 +/- 2.3%) (p < 0.0001). Nitroglycerin-induced dilation of the two groups were similar. Upon multivariate analysis, passive smoking exposure was the strongest independent predictor (beta = -0.59; p = 0.0001) for impaired flow-mediated endothelium-dependent dilation (model R2 = 0.75, F value = 6.1, p = 0.0001).

CONCLUSIONS

In modernized Chinese, as in Caucasians, exposure to heavy environmental tobacco smoke causes arterial endothelial dysfunction, a key early event in atherosclerosis. This may have serious implications for cardiovascular health in China, currently in a process of rapid modernization.

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

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

The relationship of late potentials to assessment of heart rate variability in post-infarction patients

In order to investigate the relationship of late potential (LP) to assessment of heart rate variability (HRV) after acute myocardial infarction (AMI), we studied 101 Chinese patients with AMI (10+/-2.4 days) in Taiwan by collecting 24-h ECG from a Holter tape recorder and signal-averaged ECG from a high-resolution ECG cart. Of the 101 patients, 36 patients had LP (LP group) and 65 patients did not (NLP group). The mean heart rate was significantly lower in the LP group than in the NLP group (P<0.05). The LP group had a significantly increased high-frequency (HF) spectral component of HRV compared with the NLP group (P<0.005), but their low-frequency (LF) to HF ratio (LF/HF) was lower (P<0.05). Analysis of the circadian variation of HRV revealed significant difference of morning SDRR (standard deviation of normal RR intervals) compared with noon SDRR (P<0.05 in the LP group, P<0.005 in the NLP group) and evening SDRR (P<0.05 in the LP group, P<0.005 in the NLP group). In the NLP group, morning HF (normalized unit, nu) was 0.258+/-0.098 compared with noon HF (nu) of 0.219+/-0.83 (P<0.05) and evening HF (nu) of 0. 225+/-0.085 (P<0.05). Nine patients died during follow-up from cardiac causes, three (8.3%) in the LP group and six (9.2%) in the NLP group. In post-MI patients, there was higher vagal tone in patients with late potentials compared to those without late potentials. NLP patients had more circadian change in vagal tone compared with LP patients.

Risk factors for non-fatal acute myocardial infarction in middle-aged and older Japanese. Fukuoka Heart Study Group

It remains uncertain whether established risk factors for coronary heart disease in middle-aged persons can be generalized to elderly persons. Based on a case-control study, risk factors for nonfatal acute myocardial infarction (AMI) were assessed separately in middle-aged (40-64 years) and older (65-79 years) Japanese. Eligible cases were patients who were admitted to 22 collaborating hospitals for the first AMI between September 1996 and January 1998. Community controls were recruited by using the resident registers of the municipalities with individual matching by gender, year of birth (within 2 years), and proximity in residence. The present study used 384 sets of 384 cases and 656 controls. Smoking, hypertension, and angina pectoris were associated with an increased risk of AMI, and alcohol use and leisure-time exercise were related to a decreased risk of AMI in the elderly as well as in middle-aged persons. There was no apparent relation between body mass index and AMI in either middle-aged or older adults. Diabetes mellitus was significantly associated with an increased risk of AMI in older persons, but not in middle-aged persons. Hypercholesterolemia was related to an increased risk of AMI in middle-aged individuals alone. The findings suggest that risk factors for AMI in the elderly are generally similar to those of middle-aged persons, but provide no evidence that hypercholesterolemia in the elderly is an important risk factor.

New risk factors for coronary heart disease in Asia

The increasing prevalence of traditional atherosclerotic risk factors have been documented in Asia but the real impact on prevalence of coronary heart disease (CHD) remains unclear. Smoking, hypertension, hypercholesterolaemia, diabetes mellitus and obesity are present in only 50% of CHD. In community studies of Chinese in Hong Kong and southern mainland-China, aging, smoking and hypercholesterolaemia were found to have a less impact on endothelial function in the Chinese compared with Caucasians in London and Sydney. As endothelial dysfunction is an early event in atherogenesis, there will be a strong need to search for newer risk factors for CHD in Asia, which may become more important in many Asian countries now in the process of modernization. Recently, heterozygous hyperhomocysteinaemia (with or without folate deficiency) was found to be an independent risk factor for arterial endothelial dysfunction, and hyperhomocysteinaemia in association with smoking was a significant risk factor for premature coronary heart disease in Hong Kong Chinese. Other newer factors which have emerged include folate deficiency, low HDL-cholesterol, insulin resistance, abdominal obesity, Methylene-tetrahydrofolate Reductase and Angiotensin Converting Enzyme gene polymorphism.

Low levels of cardiovascular risk factors and coronary heart disease in a UK Chinese population

OBJECTIVE

To compare the prevalence of cardiovascular risk factors and coronary heart disease in Chinese and Europid adults.

DESIGN

Population based, cross sectional survey.

SETTING

Newcastle upon Tyne, UK, 1991-93.

SUBJECTS

Altogether 380 Chinese and 625 Europid adults, aged 25-64 years.

MAIN OUTCOME MEASURES

Fasting lipid levels, blood pressure, body mass index (BMI), the proportions who smoked, and the prevalence of coronary heart disease based on the Rose angina questionnaire and major electrocardiographic abnormalities on resting 12 lead electrocardiogram (Minnesota codes 1.1-1.2). All figures were age adjusted to the 1991 England and Wales population.

RESULTS

Altogether 183 and 197 Chinese, and 310 and 315 Europid men and women respectively were seen. Compared with Europid men, Chinese men had a lower mean total cholesterol concentration (5.1 versus 5.6 mmol/l, p < 0.001) and LDL cholesterol (3.2 versus 3.6 mmol/l, p < 0.001); lower BMI values (23.8 versus 26.1 kg/m-2, p < 0.001); and smoked less (23% versus 35%, p < 0.01)). Compared with Europid women, Chinese women also had lower mean lipid levels (total cholesterol: 4.9 versus 5.4 mmol/l p < 0.001, LDL cholesterol: 2.8 versus 3.1 mmol/l p < 0.001); BMI values (23.5 versus 26.1 kg/m-2, p < 0.001); and far fewer were smokers (1.4% versus 33%, p < 0.001). Chinese women, however, had higher mean systolic (121 versus 117 mmHg, p > 0.05) and diastolic (75 versus 68 mmHg, p < 0.001) blood pressures. The prevalence of coronary heart disease was significantly lower in Chinese than Europid men (4.9% versus 16.6%, p < 0.001) but not significantly different in women (7.3% versus 11.1%, p = 0.16).

CONCLUSION

Strategies for UK Chinese are needed to maintain this favourable risk factor profile and prevent any potential increase in the risk of coronary heart disease associated with increasing acculturation.

Hyperhomocysteinaemia and premature coronary artery disease in the Chinese

OBJECTIVES

To examine the prevalence of hyperhomocysteinaemia and compare it with the classic risk factors and vitamin status in Hong Kong Chinese patients with premature atherosclerotic coronary artery disease.

DESIGN

Case-control study.

SETTING

General hospital and community.

SUBJECTS

Forty five patients (39 males) with significant coronary artery disease confirmed by angiography (32 post myocardial infarction) and 23 healthy volunteers (17 male), all aged less than 55 years.

INTERVENTION

Standardised methionine-loading test.

MAIN OUTCOME MEASURES

Coronary artery disease, risk factors.

RESULTS

More patients than controls had fasting hyperhomocysteinaemia (10/45 v 2/23, P = 0.122), post-methionine hyperhomocysteinaemia (17/45 v 1/23, P = 0.008), and an abnormal response to methionine (15/45 v 1/23, P = 0.015). A history of smoking was more frequent in patients (3/23 v 25/45, P = 0.002). Sixteen of 17 patients with hyperhomocysteinaemia but only nine of 28 with normohomocysteinaemia were smokers (P = 0.0002). Fasting plasma cholesterol concentrations (mean (SD)) were higher in hyperhomocysteinaemic patients (6.41 (1.58) mmol/l) than in controls (5.53 (0.90) mmol/l) (P = 0.042). Serum vitamin B-12 was not reduced and serum folate was higher in hyperhomocysteinaemic patients (35 (4) nmol/l) than normohomocysteinaemic patients (26 (9) nmol/l) (P = 0.009).

CONCLUSIONS

Although the prevalence of hyperhomocysteinaemia in Hong Kong Chinese is similar to that in white subjects, hyperhomocysteinaemia is not an independent risk factor for coronary artery disease and is associated with smoking. This may be of some consequence in view of the change to a more Western diet with more animal protein, and therefore methionine, coupled with a high frequency of cigarette smokers in this region. The causes of the hyperhomocysteinaemia are multifactorial but in this pilot study a deficiency of folate and/or vitamin B-12 did not seem to be one of them.

Dietary supplementation with orange and carrot juice in cigarette smokers lowers oxidation products in copper-oxidized low-density lipoproteins

OBJECTIVE

Our objective was to evaluate the effect of daily supplementation with foods high in vitamin C and beta carotene on plasma vitamin levels and oxidation of low-density lipoprotein (LDL) in cigarette smokers.

SUBJECTS

Fifteen normolipidemic male cigarette smokers who did not usually take vitamin supplements were recruited into the study.

INTERVENTIONS

Throughout the study, subjects consumed a diet rich in polyunsaturated fatty acids, which provided 36% of energy as fat: 18% from meat, dairy products, vegetable oils, and fat spreads and 18% from walnuts (68 g/day). Subjects consumed a vitamin-free drink daily for 3 weeks; then for 3 weeks they consumed daily supplements of orange juice (145 mg vitamin C) and carrot juice (16 mg beta carotene).

RESULTS

Vitamin-rich food supplements raised plasma levels of ascorbic acid (1.6-fold; P < .01) and beta carotene (2.6-fold; P < .01). Malondialdehyde, one end product of oxidation, was lower in copper-oxidized LDL after vitamin supplementation (mean +/- standard error = 65.7 +/- 2.0 and 57.5 +/- 2.9 mumol/g LDL protein before and after supplementation, respectively; P < .01). Rate of LDL oxidation and lag time before the onset of LDL oxidation were not affected by antioxidant supplementation.

CONCLUSIONS

In habitual cigarette smokers, antioxidant vitamins, which can be feasibly provided from food, partly protected LDL from oxidation despite a diet rich in polyunsaturated fatty acids.