How low should we target the LDL goal to improve survival for acute coronary syndrome patients in Hong Kong?

BACKGROUND

Utilization of lipid-lowering agents has been associated with improved long-term outcomes in acute coronary syndrome (ACS) patients. However, updated data regarding local use and outcomes was lacking.

METHODS

We retrospectively reviewed 696 hospitalized patients in the local ACS registry of Prince of Wales Hospital during 1 January 2008 to 31 December 2009 with data retrieved using computerized clinical records of all patients.

RESULTS

Among the 402 MI patients included, 104 (25.9 %) were not prescribed with statins at discharge. Percutaneous coronary intervention (PCI) not performed or planned during hospitalization (OR: 0.324, p = 0.001) and latest lower LDL-C level before discharge (OR: 0.221 for an increment of 1 mmol/L, p = 0.009) were significant independent predictors of the absence of statin prescriptions at discharge. A significantly lower all-cause mortality rate (14.4 % vs 51.7 %, p < 0.001), fewer total hospitalizations (p < 0.001) and fewer hospitalizations due to cardiovascular problems (p < 0.001) were observed in patients discharged with statins. LDL-C goal attainment of < 2.6 mmol/L resulted in a significant reduction in mortality (10.8 % vs 24.2 %, p = 0.001), but not for goal attainment of < 1.8 mmol/L. Significant difference in survival existed only when LDL-C cut-off values were above 2.4 mmol/L.

CONCLUSIONS

This study revealed the under-utilization of statin therapy in eligible MI patients at discharge and unsatisfactory percentages of LDL-C goal attainment, and also reassured the role of low LDL-C reduction to < 2.6 mmol/L in the management of MI. However, the current study did not show that the lower LDL-C reduction improved survival of ACS patients. Further research should be conducted to assess the necessity of aggressive LDL-C reduction to < 1.8 mmol/L in local patients.

Recipient-related risk factors for graft failure and death in elderly kidney transplant recipients

BACKGROUND

Elderly patients with end-stage renal disease have become the fastest growing population of kidney transplant candidates in recent years. However, the risk factors associated with long-term outcomes in these patients remain unclear.

METHODS

We retrospectively analyzed 166 recipients aged 60 years or older who underwent primary deceased kidney transplantation between 2002 and 2013 in our center. The main outcomes included 1-, 3- and 5-year patient survival as well as overall and death-censored graft survival. The independent risk factors affecting graft and patient survival were analyzed using Cox regression analysis.

RESULTS

The 1-, 3-, 5-year death-censored graft survival rates were 93.6%, 89.4% and 83.6%, respectively. Based on the Cox multivariate analysis, panel reactive antibody (PRA)>5% [hazard ratio (HR) 4.295, 95% confidence interval (CI) 1.321-13.97], delayed graft function (HR 4.744, 95% CI 1.611-13.973) and acute rejection (HR 4.971, 95% CI 1.516-16.301) were independent risk factors for graft failure. The 1-, 3-, 5-year patient survival rates were 84.8%, 82.1% and 77.1%, respectively. Longer dialysis time (HR 1.011 for 1-month increase, 95% CI 1.002-1.020), graft loss (HR 3.501, 95% CI 1.559-7.865) and low-dose ganciclovir prophylaxis (1.5 g/d for 3 months) (HR 3.173, 95% CI 1.063-9.473) were risk factors associated with patient death.

CONCLUSIONS

The five-year results show an excellent graft and patient survival in elderly kidney transplant recipients aged ≥60 years. PRA>5%, delayed graft function, and acute rejection are risk factors for graft failure, while longer duration of dialysis, graft loss and low-dose ganciclovir prophylaxis are risk factors for mortality in elderly recipients. These factors represent potential targets for interventions aimed at improving graft and patient survival in elderly recipients.

Serum lipids, apolipoproteins, and mortality among coronary artery disease patients

The proatherogenic effect of low-density lipoprotein cholesterol (LDL-C) and antiatherogenic effect of high-density lipoprotein cholesterol (HDL-C) have been confirmed in general population. But controversy arises among coronary artery disease (CAD) patients. The goal of this study was to identify the association of different lipid measurements with CAD prognosis. The study cohort included 1916 CAD patients who were 40-85 years of age. Cox proportional hazards regression models were used to estimate the association of baseline 6 lipid factors and 3 ratios with all-cause and cardiovascular (CVD) mortality. During a median follow-up of 3.1 years, 147 deaths were recorded, 113 of which were due to CVD. When lipid factors were categorized, HDL-C showed a U-shape association with all-cause and CVD mortality after adjustment for major CVD risk factors. Serum LDL-C, apoB, LDL/HDL ratio, and apoB/apoA-I ratio were positively, and apoA-I level was inversely associated with the risk of CVD mortality. After further pairwise comparison of lipid-related risk, LDL/HDL ratio and LDL-C had stronger association with all-cause and CVD mortality than other proatherogenic measurements among Chinese CAD patients.

Adverse trends of cardiovascular risk factors among low risk populations (1983-1994)--a cohort study of workers and farmers in Guangzhou, China

BACKGROUND

The levels and trends of cardiovascular risk factors vary greatly throughout China. We examine 10-year trends of cardiovascular risk factors (1983-1994) and the factors related to these trends among low-risk cohorts of workers and farmers in Guangzhou, China.

METHODS

This is a cohort study of 3,131 workers and 3,493 farmers aged 25-64 years at baseline with 10 years of follow-up. We performed a longitudinal analysis to account for the aging of the cohorts and the repeated measures of the same individual.

RESULTS

At baseline the prevalence of overweight (including obese) ranged from 1.0% to 11.8%, hypertension ranged from 3.8% to 10.5%, and mean serum total cholesterol (TC) ranged from 155.4 mg/dl to 187.2 mg/dl. Although prevalence of smoking declined, blood pressure levels and body mass index (BMI) increased significantly, and lipid profiles changed unfavorably during the 10-year follow-ups. The prevalence of hypertension increased from 5.0 percentage points (female farmers) to 12.3 percentage points (male farmers). Mean TC increased significantly (e.g., +22.8 mg/dl and +17.0 mg/dl in male and female farmers, respectively). In the longitudinal data analyses, increase in BMI was associated with increase in blood pressure levels and TC. Significant adverse trends of risk factors persisted after adjustment for aging, education, BMI, smoking, and alcohol intake.

CONCLUSION

Urgent action is needed to prevent and reverse the unhealthy trends occurring among these low risk Chinese workers and farmers.

Prevalence and associated factors of dyslipidemia in the adult Chinese population

To determine the prevalence, associated factors, awareness and control of dyslipidemia in Chinese living in Greater Beijing, we measured the serum cholesterol concentration in 3251 Chinese adults (age: 45 to 89 years) as participants of the population-based Beijing Eye Study 2006. Additional information on treatment of dyslipidemia was obtained using a standard questionnaire. The mean concentrations of total, HDL cholesterol, LDL cholesterol and triglycerides were 4.92±1.01 mmol/L, 1.61±0.36 mmol/L, 2.88±0.85 mmol/L, and 1.76±1.29 mmol/L, respectively. Prevalence of dyslipidemia was 56.1±0.9%%. Presence of dyslipidemia was significantly associated with increasing age (odds ratio (OR):1.02; 95% confidence interval (CI): 1.01, 1.03), female gender (OR:1.51; 95%CI: 1.25, 1.83), urban region (OR:1.82; 95%CI: 1.30, 2.55), body mass index (OR:1.13; 95%CI: 1.10, 1.15), income (OR:1.11; 95%CI:1.02, 1.21), blood glucose concentration (OR:1.10; 95%CI:1.05, 1.16), diastolic blood pressure (OR:1.02; 95%CI: 1.01, 1.03), and smoking (OR:1.23; 1.01, 1.51). Among those who had dyslipidemia, the proportion of subjects who were aware, treated and controlled was 50.9%, 23.8%, and 39.91%, respectively. The awareness rate was associated with urban region (P = 0.001; OR: 6.50), body mass index (P = 0.001; OR:1.06), and income (P = 0.02; OR:1.14). The data suggest that dyslipidemia may be present in about 56% of the population aged 45+ years in Greater Beijing. Factors likely associated with dyslipidemia were higher age, female gender, urban region, higher body mass index, higher income, higher blood concentration of glucose, higher diastolic blood pressure, and smoking. In the examined study population, treatment rate was 24% with about 60% of the treated subjects still having uncontrolled dyslipidemia.

Cholesterol goal attainment in patients with coronary heart disease and elevated coronary risk: results of the Hong Kong hospital audit study

OBJECTIVE

We sought to determine 1) long-term lipid-lowering treatment patterns; 2) cholesterol goal attainment rates and possible determinants of goal achievement; and 3) effects of cholesterol goal attainment on coronary events in hospitalized Hong Kong patients.

METHODS

In this retrospective cohort analysis, records of two public Hong Kong hospitals were reviewed for 196 adults (69% with coronary heart disease (CHD) or CHD-risk equivalent) who received at least one lipid-lowering therapy during hospitalization. Low-density lipoprotein cholesterol (LDL-C) targets were <2.6 mmol/l (<100 mg/dL) for patients with CHD or CHD risk equivalents and <3.37 mmol/l (<130 mg/dL) for those without.

RESULTS

Most participants were initiated on regimens of low to midequipotency doses and never had their regimens adjusted to higher potency. Approximately 44% of patients not at LDL-C at baseline failed to achieve goal during a median follow-up of 1.9 years. Patients with higher coronary risk and/or LDL-C levels at baseline were less likely than their lower-risk counterparts to achieve goal; for each 1-mmol/l (38.7-mg/dL) increase in LDL-C at baseline, the likelihood of attaining goal declined by 64%. Patients achieving cholesterol goal had significantly longer cardiovascular event-free times.

CONCLUSIONS

A total of 44% of Hong Kong patients not at LDL-C goals at baseline did not achieve them over 1.9 years. More effective and well-tolerated therapies, including adjunctive regimens (e.g., ezetimibe-statin, niacin-statin), may be necessary to enhance LDL-C goal achievement and increase event-free time.

A risk score predicted coronary heart disease and stroke in a Chinese cohort

BACKGROUND AND OBJECTIVE

This article aims to address two issues: first, whether risk scores derived from Caucasian cohorts can accurately predict coronary heart disease (CHD) in a Chinese population; second, derivation and validation of a new risk prediction score for cardiovascular disease (CVD) from a Chinese cohort.

METHODS

A cohort of 4,400 male steelworkers (18-74 years old) recruited between 1974-1980 was followed up for an average 13.5 years. A Cox model was used to predict 10 year risk of CHD, ischemic, and hemorrhagic stroke based on blood pressure, age, total cholesterol, body mass index, and smoking status.

RESULTS

The prediction rule from the European Recommendations greatly overestimates the risk of CHD in Orientals. The new models had good predictive ability, with the area under receiver operating characteristic curves (AUCs area) in the derivation set being 0.76, 0.72, and 0.82 for CHD, ischemic, and hemorrhagic stroke separately; AUCs in the validation set were equally good, at 0.76, 0.78, and 0.82, respectively.

CONCLUSION

The risk stratification rules derived from Caucasian cohorts overestimates the CHD risk in Orientals, and we derive a specific risk stratification rule for CHD, ischemic and hemorrhagic stroke for Chinese men.

Coronary heart disease mortality for six ethnic groups in California, 1990–2000

PURPOSE

To investigate ethnic variations in coronary heart disease death in California, the authors examined total and CHD-specific mortality among non-Hispanic white (white), Hispanic, non-Hispanic black (black), Chinese, Japanese, and Asian Indian Americans. Deaths were identified in the California Mortality Database and population information was derived from the 1990 and 2000 censuses.

METHODS

Age-standardized death rates per 100,000 population were calculated for ages 25 to 84 years from 1990 to 2000. Proportional mortality ratios (PMRs) for each sex and age group were calculated by dividing the proportion of deaths due to CHD in each ethnic group by the proportion of deaths due to CHD in the total population.

RESULTS

Blacks had the highest all-cause age-standardized death rates among men (1614) and women (1014). Blacks had the highest CHD death rates among men (272) and women (190). PMRs for CHD were highest in Asian Indian men (161) and women (144), reflective of the higher percentage of CHD deaths compared with all cause deaths in this group. All sex-ethnic groups showed a decline in all cause and CHD mortality compared with the period between 1985 and 1990, except Asian Indian women, who experienced a 16% increase in all cause mortality and 5% increase in CHD mortality.

CONCLUSIONS

There is considerable heterogeneity in CHD mortality among ethnic subgroups, and additional research is needed to guide treatment and prevention efforts. Blacks and Asian Indians in California are identified as particularly high risk populations.

Secular growth and its harmful ramifications

Secular growth has been occurring in Europe for about 150 years. In the USA, since 1900, each new generation has increased by an average of 1in (2.54cm) in height and about 10lb (4.54kg) in weight. This trend has generally been viewed as favorable and tallness is admired, with the current ideal height for a man in the Western world being 6ft 2in (188cm). The Japanese have increased in height since the end of the Second World War by about 5in (12.7cm) in height and the Chinese have been growing at the rate of 2.54cm/decade since the 1950s. In spite of admiring greater height, a world population of increasing height and body-weight is a major threat to our environment, health and survival. Based on more than two decades of research, quantitative data are given for increased use of resources, and increased pollution, energy and fiscal costs resulting from a population of larger people. The laws of scaling are described to show why the impact of increasing stature has a non-linear impact on consumption, body-weight, strength, pollution and economic costs. Paleontological findings indicating that larger body size increases the risk of extinction are also discussed. Various studies indicate a loss of 0.47 year of longevity for each cm increment of height. Caloric restricted diets are also reviewed for their applicability to humans. Recommendations are made for dietary practices to moderate growth in our youth and to postpone development of chronic or degenerative diseases.

The protective role of high-density lipoproteins in atherosclerosis

Serum high-density lipoprotein level is known to be correlated inversely with the incidence and mortality rates of ischemic heart disease. Although some reports pointed out that in case of hyperalphalipoproteinemia, lesions in the coronary arteries were occasionally found, it is also noticed that in very rare condition, no atheromatous lesions found even in patients with hereditary alphalipoprotein deficiency (Funke et al., 1991). However, clinical surveys have confirmed that high high-density-lipoprotein cholesterol level is favorable in preventing the development of atheroclerotic lesion and high-density lipoprotein together with apolipoprotein AI are currently considered to be the most reliable parameters in predicting the development of atherosclerosis in hyperlipidemia.

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.

Prevalence of cardiovascular diseases in elderly Chinese people in Taiwan

In order to study the health status and prevalence of diseases in elderly Chinese people in Taiwan, a hospital-based, physician-conducted epidemiological survey was undertaken. Study subjects were people aged > or = 65 years who were randomly selected from four regions of Taiwan. A total of 2600 subjects were studied. Most of the study subjects visited the hospitals for detailed history taking, physical examination and laboratory tests, including urinalysis, blood chemistry, electrocardiography, and chest and lumbar spine radiography. The cardiovascular data of 2518 subjects (males 1283) comprised this report. The prevalence of hypertension in the aged Chinese in Taiwan was high in both males and females (males 33.2%, females 40.9%, combined 37%). Coronary artery disease was also common (11.4%), but the prevalence was relatively low compared with Western people. Other cardiovascular diseases such as aortic aneurysm and valvular heart disease were rare. About 70% of the electrocardiograms were found abnormal. This well-organized, large-scale epidemiological survey not only presents useful information for local medical care for the elderly but also provides important data for comparison between different people in the world.

Phenotypic variation in heterozygous familial hypercholesterolemia: a comparison of Chinese patients with the same or similar mutations in the LDL receptor gene in China or Canada

Familial hypercholesterolemia (FH) is caused by mutations in the LDL receptor (LDLR) gene and is usually associated with hypercholesterolemia, lipid deposition in tissues, and premature coronary artery disease (CAD). However, individuals with heterozygous FH in China exhibit a milder phenotype despite having deleterious mutations in the LDLR gene (X.-M. Sun et al, Arterioscler Thromb. 1994;14:85-94). Nineteen Chinese FH heterozygotes living in Canada were screened for the 11 mutations that had been described in FH patients living in China. One Chinese Canadian carried one of these mutations (Trp462Stop), 2 carried a previously unreported single-base substitution (Cysl63Arg), and 1 carried a mutation observed in French-Canadian patients (Glu207Lys). Twelve additional carriers of these mutations were identified in the families of the index patients. Significantly higher LDL cholesterol concentrations were observed in FH heterozygotes with defined mutations living in Canada (mean+/-SD, 7.46+/-1.29, n=16) than in those living in China (4.35+/-1.09, n=18; P<.0001). Six of the 16 FH heterozygotes residingin Canada had evidence of tendon xanthomata and 4 had a history of premature CAD, whereas none of those in China had tendon xanthomata or CAD. Complete segregation between hypercholesterolemia and inheritance of a mutant allele was observed in 3 Canadian Chinese FH families. Thus, Chinese FH heterozygotes living in Canada exhibit a phenotype similar to that of other FH patients in Western societies. The difference between patients living in Canada and those living in China could be ascribed to differences in dietary fat consumption, showing that environmental factors such as diet play a significant role in modulating the phenotype of heterozygous FH.

Classifying ethnicity utilizing the Canadian Mortality Data Base

The study of ethnic differences in disease is a methodological challenge as ethnicity is often not identified in existing datasets and surrogate measures need to be used. We have developed a novel methodology combining last name and country of birth to study mortality patterns of Canadians of South Asian (SA) and Chinese (CH) ethnic origin and have compared death rates among SA, CH, and White (WH) Canadians.

METHODS

SA and CH were identified in the Canadian Mortality Data Base (CMDB) using the last name and country of birth of the deceased. Records of people who had been born in countries with large South Asian and Chinese populations (e.g. India, Pakistan, China, Hong Kong) were selected and manually screened by last name. A name directory was then created of distinct South Asian and Chinese names and this directory was used to search all other records in the CMDB for SA and CH deaths. Where necessary, other identifying characteristics such as first name and parents' last name were also used. Population counts were obtained from the Census self-reported question on ethnicity for SA and CH. WH were identified as non-immigrant Canadians who were neither SA nor CH. The method of assigning ethnicity in the CMDB and Census were assessed for comparability and issues of validity and reliability were addressed.

RESULTS

Using this method, 10,989 SA and 21,548 CH deaths were identified. There was marked heterogeneity in birthplace, with only 56% of SA born in South Asia and only 74% of CH born in Greater China. Last names had high validity for self-reported ethnicity in a population sample of SA and were highly reproducible. Mortality rates varied dramatically between groups studied. SA and WH had high rates of ischemic heart disease while stroke mortality was similar among all three groups. Cancer death rates were high in CH and WH and much lower in SA.

CONCLUSION

Last names and country of birth can be used to determined ethnicity of SA and CH with validity and reliability, and leads to a more accurate classification than country of birth alone. The contrasting patterns observed in mortality from major causes of death suggest many interesting hypotheses for further study.

Prevalence of coronary heart disease in Kin-Chen, Kinmen

We estimated the prevalence of coronary heart disease (CHD) by the Minnesota code of a 12-lead resting electrocardiogram, Rose chest pain questionnaire and self-reported previous medical history in Kin-Chen, Kinmen (Quemoy), an island under military control for 40 years and the focal point of confrontation between mainland China and Taiwan. Among the target population of 6346 who accounted for all residents aged over 30, 3826 (60.3%) responded with complete data. The prevalence of probable CHD (Minnesota code 1.1-1.2) was 4.1% (71/1732) in men and 4.0% (84/2094) in women, whereas the prevalence of possible CHD (Minnesota code 1.3, 4.1-4.4, 5.1-5.3 and 7.1.1) was significantly higher in women (21.4%) than in men (11.6%). When compared to Chinese populations elsewhere, the increased overall prevalence may suggest a link to long-term stress conditions under military control. We also found the abnormal ECG was associated with many risk factors of CHD, particularly win women. The prevalence of Rose angina and self-reported angina or myocardial infarction was, however, low and associated poorly with any cardiovascular risk factors. Long-term follow-up studies are needed to determine the predictive value of these electrocardiographic abnormalities for cardiovascular disease morbidity and mortality in this population.

A population-based epidemiological study on cardiovascular risk factors in Kin-Chen, Kinmen

We conducted a population survey of cardiovascular risk factors in Kin-Chen, Kinmen (Quemoy), an island under military control for 40 years and the focal point of confrontation between mainland China and Taiwan. During the period 1992-1994, all residents > or = 30 years of age in Kin-Chen, the largest township in Kinmen, were invited to participate. The response rate was 60.3% (3826/6346). The prevalence of hypertension (> or = 160/95 mmHg and/or under treatment) was 25.2% in men and 17.6% in women. The rate for smoking was 41.5% in men and 2.9% in women. The prevalence of diabetes was 6.7% in men and 6.4% in women. Mean values for systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol were 135.3 mmHg, 85.5 mmHg, 5.3 mmol/l, 1.1 mmol/l, 3.5 mmol/l and 1.4 mmol/l in men; and 128.0 mmHg, 79.5 mmHg, 5.2 mmol/l, 1.0 mmol/l, 3.3 mmol/l and 1.5 mmol/l in women, respectively. The unexpectedly high prevalence of hypertension in Kin-Chen male may reflect the effect of more than 40 years of military control and discipline. The high serum cholesterol level in Kin-Chen relative to mainland China and the low triglyceride level relative to Taiwan and Beijing, suggest further study of the contributions of diet and other psychosocial or environmental factors.

A preliminary study of potential dietary risk factors for coronary heart disease among Chinese American adolescents

This study investigated dietary knowledge, attitudes toward diet, behavioral factors affecting diet, and dietary patterns between American Chinese middle school students and Chinese middle school students living in China. Significant differences occurred in these variables between the two groups of students. Chinese students living in China had less knowledge and a less favorable attitude. However, they exhibited more positive behavioral factors affecting diet which include culture, religion, customs, economic factors, beliefs, and values. As for the dietary pattern, Chinese student living in China consumed less meat, dairy products, fat, sweets and snacks, and fast foods, and consumed more fruits, vegetables, and starch.

Humans, lipids and evolution

The genetically ordered physiology of contemporary humans was selected over eons of evolutionary experience for a nutritional pattern affording much less fat, particularly less saturated fat. Current dietary recommendations do not accord exactly with those generated by an understanding of prior hominoid/hominid evolution. Similarly, widely advocated standards for serum cholesterol values fail to match those observed in recently studied hunter-gatherers, whose experience represents the closest living approximation of "natural" human lipid metabolism. The evolutionary paradigm suggests that fats should comprise 20-25% of total energy intake, that the ratio of polyunsaturated to saturated fat should exceed 1.0, and that total serum cholesterol levels should be below 150 mg/dL (approximately 4 mM/L).

Human aortic proteoglycans of subjects from districts of high and low prevalence of atherosclerosis in China

The contents of three species of proteoglycans (PGs), heparan sulfate PG(HSPG), chondroitin sulfate PG(CSPG) and dermatan sulfate chondroitin sulfate PG(DSCSPG), in human thoracic aortas of subjects from districts of high (Beijin, in North China) and low (Nanning, in South China) prevalence of atherosclerosis in China were quantitated. Higher aortic HSPG and DSCSPG (but lower DS) in samples from Nanning than those from Beijing might be implicated in the lower prevalence of atherosclerosis in the former.