The real contribution of the major risk factors to the coronary epidemics: time to end the "only-50%" myth

Successful Aging: The Role of Physical Activity

Although no amount of physical activity can stop the aging process, a moderate amount of regular exercise can minimize the physiological effects of an otherwise sedentary lifestyle and increase active life expectancy by limiting the development and progression of chronic disease and disabling conditions. Ideally, exercise prescription for older adults should include aerobic, muscle strengthening, and flexibility exercises. In addition, individuals at risk for falling or mobility impairment should also perform specific exercises to improve balance. The intensity and duration of physical activity should be low at the outset for those who are highly deconditioned, are functionally limited, or have chronic conditions affecting their ability to perform physical tasks. Furthermore, the progression of activities should be individualized and tailored to tolerance and preference. Incorporating principles of behavioral change into the design and application of exercise and physical activity programs will increase the likelihood of an individual initiating and maintaining a regular program of exercise and/ or physical activity. Strategies for maintaining physical function and improving overall health of older adults with chronic conditions and disability are discussed. All older adults with and without disabilities should be encouraged to develop a personalized physical activity plan that meets their needs and personal preferences.

The accumulative effects of modifiable risk factors on inflammation and haemostasis

Various modifiable risk factors have been associated with inflammation and haemostasis, although the accumulative effects have not yet been examined. We therefore explored additive and independent associations of modifiable risk factors (smoking, alcohol, cholesterol, obesity, hypertension, physical activity) with inflammatory (CRP) and haemostatic (fibrinogen) markers. Data were collected from a sample of 7670 healthy asymptomatic participants (45.9% men, aged 46.2+/-15.6 years). A graded increase in the risk of inflammation (CRP> or =3 mg/L) with increasing numbers of modifiable risk factors was demonstrated (odds ratio for > or =4 risk factors=5.09, 95% CI, 3.96-6.55). Similar associations were found in relation to haemostasis. Central adiposity was the strongest independent predictor of inflammation (OR=3.45, 95% CI, 3.07-3.87) although smoking most strongly predicted haemostasis (OR=2.19, 95% CI, 1.94-2.48). These findings suggest that targeting multiple risk factors is likely to have the greatest benefit for cardiovascular prevention.

Prevalence trends for myocardial infarction and conventional risk factors among Greek adults (2002-06)

AIM

To examine trends in the prevalence of myocardial infarction (MI) and conventional risk factors in Greek adults between 2002 and 2006.

DESIGN

Repeated cross-sectional study.

METHODS

Self-reported data from surveys given in Salamis during two election days in 2002 and 2006 were analysed. The same sampling method and procedures were used on both surveys. The study sample included 2805 and 3478 subjects (> or =20 years) in 2002 and 2006, respectively, with similar age and sex distribution to the target population.

RESULTS

The prevalence of MI increased from 4.1% (men, 6.3%; women, 1.9%) in 2002 to 4.8% (men, 7.3%; women, 2.2%) in 2006 (P = 0.18). At the same time, prevalence rates of major risk factors were as follows: diabetes increased from 8.7% to 10.3% (P = 0.037), hypertension from 20.1% to 25.7% (P < 0.001) and hypercholesterolemia (cholesterol >240 mg/dl or the use of cholesterol-lowering medication) increased from 17.5% to 22.3% (P < 0.001). Prevalence of current smokers in 2002 (defined as persons who smoked > or =5 cigarettes/day) was 37.0% and in 2006 (defined as those who smoked > or =1 cigarettes/day) was 40.1%. Logistic regression analysis showed that the aforementioned risk factors were significantly associated with MI in both surveys; the factor that showed the greatest magnitude of association with MI was hypercholesterolemia, followed by diabetes, hypertension and smoking.

CONCLUSION

These findings show that, in the Greek population, prevalence of MI continues to rise (at approximately 4% per year). This trend seems to be driven by a persistently high prevalence of smoking and the rapidly increasing burden of diabetes, hypertension and hypercholesterolemia.

How to identify patients with vulnerable plaques

Multiple strategies are available for clinicians to identify patients at high risk for cardiovascular events. Two commonly discussed strategies are the identification of vulnerable plaques and the identification of vulnerable patients. The strategy of identifying vulnerable patients is less invasive, easy to implement and not restricted primarily to one vascular bed (e.g. coronary or cerebral). This review discusses the utility as well as the limitations of global risk assessment tools to identify such patients. The utility of biomarkers [C-reactive protein, lipoprotein-associated phospholipase A(2) and lipoprotein(a)] and non-invasive measures of atherosclerosis burden (coronary artery calcium scores, carotid intima-media thickness and ankle-brachial index) in identifying patients at high risk for cardiovascular events are also discussed.

C-reactive protein, established risk factors and social inequalities in cardiovascular disease - the significance of absolute versus relative measures of disease

Background

The widespread use of relative scales in socioepidemiological studies has recently been criticized. The criticism is based mainly on the fact that the importance of different risk factors in explaining social inequalities in cardiovascular disease (CVD) varies, depending on which scale is used to measure social inequalities. The present study examines the importance of established risk factors, as opposed to low-grade inflammation, in explaining socioeconomic differences in the incidence of CVD, using both relative and absolute scales.

Methods

We obtained information on socioeconomic position (SEP), established risk factors (smoking, hypertension, and hyperlipidemia), and low-grade inflammation as measured by high-sensitive (hs) C-reactive protein (CRP) levels, in 4,268 Swedish men and women who participated in the Malmö Diet and Cancer Study (MDCS). Data on first cardiovascular events, i.e., stroke or coronary event (CE), was collected from regional and national registers. Social inequalities were measured in relative terms, i.e., as ratios between incidence rates in groups with lower and higher SEP, and also in absolute terms, i.e., as the absolute difference in incidence rates in groups with lower and higher SEP.

Results

Those with low SEP had a higher risk of future CVD. Adjustment for risk factors resulted in a rather small reduction in the relative socioeconomic gradient, namely 8% for CRP (≥ 3 mg/L) and 21% for established risk factors taken together. However, there was a reduction of 18% in the absolute socioeconomic gradient when looking at subjects with CRP-levels < 3 mg/L, and of 69% when looking at a low-risk population with no smoking, hypertension, or hyperlipidemia.

Conclusion

C-reactive protein and established risk factors all contribute to socioeconomic differences in CVD. However, conclusions on the importance of "modern" risk factors (here, CRP), as opposed to established risk factors, in the association between SEP and CVD depend on the scale on which social inequalities are measured. The one-sided use of the relative scale, without including a background of absolute levels of disease, and of what causes disease, can consequently prevent efforts to reduce established risk factors by giving priority to research and preventive programs looking in new directions.

Global burden of blood-pressure-related disease, 2001

BACKGROUND

Few studies have assessed the extent and distribution of the blood-pressure burden worldwide. The aim of this study was to quantify the global burden of disease related to high blood pressure.

METHODS

Worldwide burden of disease attributable to high blood pressure (> or =115 mm Hg systolic) was estimated for groups according to age (> or =30 years), sex, and World Bank region in the year 2001. Population impact fractions were calculated with data for mean systolic blood pressure, burden of deaths and disability-adjusted life years (DALYs), and relative risk corrected for regression dilution bias.

FINDINGS

Worldwide, 7.6 million premature deaths (about 13.5% of the global total) and 92 million DALYs (6.0% of the global total) were attributed to high blood pressure. About 54% of stroke and 47% of ischaemic heart disease worldwide were attributable to high blood pressure. About half this burden was in people with hypertension; the remainder was in those with lesser degrees of high blood pressure. Overall, about 80% of the attributable burden occurred in low-income and middle-income economies, and over half occurred in people aged 45-69 years.

INTERPRETATION

Most of the disease burden caused by high blood pressure is borne by low-income and middle-income countries, by people in middle age, and by people with prehypertension. Prevention and treatment strategies restricted to individuals with hypertension will miss much blood-pressure-related disease.

Fate of incidental, asymptomatic lesions discovered during percutaneous coronary intervention

The authors aimed to determine the incidence and angiographic features associated with plaque progression requiring nontarget lesion percutaneous coronary intervention after culprit lesion percutaneous coronary intervention. Of 945 consecutive percutaneous coronary interventions reviewed, 100 patients who required nontarget lesion percutaneous coronary intervention in the following year of the index percutaneous coronary intervention were found and compared with 100 consecutive patients who did not require nontarget lesion percutaneous coronary intervention. Patients with restenosis were excluded. Incidence of clinical plaque progression leading to additional nontarget lesion percutaneous coronary intervention in the year after an index percutaneous coronary intervention was found to be 10.5%. In multivariable logistic regression analyses, the predictors of plaque progression were multivessel disease, unstable angina pectoris, diabetes mellitus, prior percutaneous coronary intervention, and lack of statin use. Initially, lesions that lead to repercutaneous coronary intervention were mostly nonsignificant. Clinical presentation of plaque progression was mostly acute coronary syndrome. Results emphasize the need for further study to refine the methods to identify potentially vulnerable but clinically silent plaques.

Prognostic role of flow-mediated dilation and cardiac risk factors in post-menopausal women

OBJECTIVES

The aim of this study was to examine the association between brachial artery flow-mediated dilation (FMD) and cardiovascular events in a cohort of initially asymptomatic post-menopausal women, with adjustment for the presence of the major cardiovascular risk factors.

BACKGROUND

Conventional major cardiovascular risk factors (cigarette smoking, hypercholesterolemia, hypertension, and diabetes) fail to explain nearly 50% of cardiovascular events. Defining the magnitude of future risk for the development of clinical events is a major focus of effective primary prevention. Evaluation of endothelial function, utilizing the noninvasive measurement of the brachial artery FMD, may serve as a screening tool to individualize high-risk patients.

METHODS

We conducted a prospective study on 2,264 post-menopausal women, age 54 +/- 6 years. The length of the follow-up was 45 +/- 13 months (range 6 to 65 months).

RESULTS

During observation, 90 major events were recorded. Risk-adjusted relative risk values resulted 1.0, 1.33 (95% confidence interval [CI] 1.09 to 4.09), and 4.42 (95% CI 2.97 to 8.01) for women in the higher, intermediate, and lower tertile of FMD, respectively (p < 0.0001 for trend). The event rate for women in the lower tertile (FMD <or=4.5%) was greater than the combined event rate noted in the other 2 tertiles (women in the lower tertile accounted for 51 events [56.6% of total events]). When added to age and other conventional cardiovascular risk factors (smoking habits, presence of hypercholesterolemia, history of diabetes, hypertension), FMD contributed significantly to the model predicting cardiovascular events (likelihood ratio chi-square change: 10.22; p < 0.0001).

CONCLUSIONS

In post-menopausal women, the knowledge of FMD provided incremental prognostic information regarding the risk of developing cardiovascular events.

Debunking the ‘only 50%’ myth: prevalence of established risk factors in New Zealanders with self-reported ischaemic heart disease

OBJECTIVE

To estimate the prevalence of established risk factors for ischaemic heart disease (IHD) in New Zealand adults and compare the prevalence in adults with and without this disease.

DESIGN

Data were obtained from the 2002/03 New Zealand Health Survey. Risk factor prevalence was determined by: self-reported doctor diagnosis of high blood pressure, high cholesterol and diabetes; self-report of smoking and physical inactivity; and measurement of obesity. Presence of IHD was based on self-report of heart disease (doctor diagnosed at age 25 years or over) together with current medical or past surgical treatment for this disease. Multiple logistic regression was used to determine prevalence rate ratios (PRRs) for males and females separately, adjusting for age, ethnicity and deprivation.

RESULTS

The overall prevalence of IHD was 8%. Overall risk factor prevalences were in the range of 20-25% for each of high blood pressure, high cholesterol, smoking, obesity and physical inactivity, and approximately 5% for diabetes. Overall, 94-97% of adults with IHD had at least one risk factor (depending on how smoking was defined). The PRRs of IHD were highest for cholesterol (about 4.5), followed by blood pressure (about 2.3), with all other risk factors around 1.5. PAF estimates indicate that 80-85% of IHD was attributable to the presence of at least one risk factor for all age, gender and ethnic groups.

CONCLUSIONS

Established risk factors account for 80-85% of the non-fatal burden of IHD in New Zealand. Limited research resources would be better used to evaluate which interventions are effective and efficient at reducing exposure of all population groups to known risk factors, rather than on identification of additional risk factors.

Examining life-course influences on chronic disease: the importance of birth cohort studies from low- and middle- income countries. An overview

The objectives of this overview are to describe the past and potential contributions of birth cohorts to understanding chronic disease aetiology; advance a justification for the maintenance of birth cohorts from low- and middle-income countries (LMIC); provide an audit of birth cohorts from LMIC; and, finally, offer possible future directions for this sphere of research. While the contribution of birth cohorts from affluent societies to understanding disease aetiology has been considerable, we describe several reasons to anticipate why the results from such studies might not be directly applied to LMIC. More than any other developing country, Brazil has a tradition of establishing, maintaining and exploiting birth cohort studies. The clear need for a broader geographical representation may be precipitated by a greater collaboration worldwide in the sharing of ideas, fieldwork experience, and cross-country cohort data comparisons in order to carry out the best science in the most efficient manner. This requires the involvement of a central overseeing body--such as the World Health Organization--that has the respect of all countries and the capacity to develop strategic plans for 'global' life-course epidemiology while addressing such issues as data-sharing. For rapid progress to be made, however, there must be minimal bureaucratic entanglements.

Comparison of relative and attributable risk of myocardial infarction and stroke according to C-reactive protein and low-density lipoprotein cholesterol levels

C-reactive protein (CRP) was proposed as a stronger predictor of cardiovascular events than low-density lipoprotein cholesterol (LDL-C); however, these associations may differ between myocardial infarction (MI) and stroke. We compared statistically the associations of CRP and LDL-C levels with risk of MI versus stroke and examined to what extent consideration of CRP or LDL-C increases the population attributable fractions (PAFs) of MI and stroke beyond traditional risk factors among 27,548 subjects from the European Prospective Investigation into Cancer and Nutrition-Potsdam Study in a case-cohort design. Among subjects without prior MI or stroke, 156 developed MI and 132 stroke during 6.0 years of follow-up. In adjusted competing risk analyses CRP was positively related to MI and stroke (P difference between endpoints = 0.55), whereas LDL-C was related to MI but not stroke (P difference between endpoints = 0.003). The PAF for smoking, diabetes, and hypertension combined was 0.76 for MI, and 0.58 for stroke. With additional consideration of CRP the PAFs were 0.80 and 0.68, while with addition of LDL-C the PAFs were 0.88 and 0.55. We conclude that CRP is equally strongly related to risk of MI and stroke, whereas LDL-C is related to risk of MI but not stroke. Consideration of LDL-C beyond smoking, diabetes and hypertension may increase the PAF of MI slightly more than CRP. In contrast, consideration of CRP but not of LDL-C may increase the PAF of stroke beyond these factors.

The gender specific frequency of risk factor and CHD diagnoses prior to incident MI: a community study

BACKGROUND

CHD is a chronic disease often present years prior to incident AMI. Earlier recognition of CHD may be associated with higher levels of recognition and treatment of CHD risk factors that may delay incident AMI. To assess timing of CHD and CHD risk factor diagnoses prior to incident AMI.

METHODS

This is a 10-year population based medical record review study that included all medical care providers in Olmsted County, Minnesota for all women and a sample of men residing in Olmsted County, MN with confirmed incident AMI between 1995 and 2000.

RESULTS

All medical care for the 10 years prior to incident AMI was reviewed for 150 women and 148 men (38% sample) in Olmsted County, MN. On average, women were older than men at the time of incident AMI (74.7 versus 65.9 years, p < 0.0001). 30.4% of the men and 52.0% of the women received diagnoses of CHD prior to incident AMI (p = 0.0002). Unrecognized and untreated CHD risk factors were present in both men (45% of men 5 years prior to AMI) and women (22% of women 5 years prior to first AMI), more common in men and those without a diagnosis of CHD prior to incident AMI (p < 0.0001).

CONCLUSION

A CHD diagnosis prior to incident AMI is associated with higher rates of recognition and treatment of CHD risk factors suggesting that diagnosing CHD prior to AMI enhances opportunities to lower the risk of future CHD events.

Socioeconomic position, co-occurrence of behavior-related risk factors, and coronary heart disease: the Finnish Public Sector study

OBJECTIVES

We examined the associations between socioeconomic position, co-occurrence of behavior-related risk factors, and the effect of these factors on the relative and absolute socioeconomic gradients in coronary heart disease.

METHODS

We obtained the socioeconomic position of 9337 men and 39,255 women who were local government employees aged 17-65 years from employers' records (the Public Sector Study, Finland). A questionnaire survey in 2000-2002 was used to collect data about smoking, heavy alcohol consumption, physical inactivity, obesity, and prevalence of coronary heart disease (myocardial infarction or angina diagnosed by a doctor).

RESULTS

The age-adjusted odds of coronary heart disease were 2.1-2.2 times higher for low-income groups than high-income groups for both men and women, and adjustment for risk factors attenuated these associations by 13%-29%. There was no further attenuation with additional adjustment for the number of co-occurring risk factors, although socioeconomic disadvantage was associated with the co-occurrence of multiple risk factors. The absolute difference in coronary heart disease risk between socioeconomic groups could not be attributed to the measured risk factors.

CONCLUSIONS

Interventions to reduce adult behavior-related risk factors may not completely remove socioeconomic differences in relative or absolute coronary heart disease risk, although they would lessen these effects.

Cardiovascular disease prevention in primary care

Since the publication of the National Service Framework for coronary heart disease, there has been a move towards primary disease prevention with a greater focus on an individual's absolute risk. Meta-analysis and systematic reviews of the evidence for primary prevention are incomplete and the current guidelines and policy have led to considerable confusion in clinical practice. There is an increased use of risk assessment tools but no effective method of reviewing current activity with the limited integration into the existing Quality Outcome Framework. There is an inadequate evidence for some of the risk factors used to identify individuals at risk, the risk calculators used to quantify the degree of risk and the methods of communicating risk to patients are largely unproven or completely missing. There is a need for a co-ordinated vascular disease prevention programme which can be applied at the individual and at the population level but is also amenable to evaluation.

Multiple biomarkers for the prediction of first major cardiovascular events and death

BACKGROUND

Few investigations have evaluated the incremental usefulness of multiple biomarkers from distinct biologic pathways for predicting the risk of cardiovascular events.

METHODS

We measured 10 biomarkers in 3209 participants attending a routine examination cycle of the Framingham Heart Study: the levels of C-reactive protein, B-type natriuretic peptide, N-terminal pro-atrial natriuretic peptide, aldosterone, renin, fibrinogen, D-dimer, plasminogen-activator inhibitor type 1, and homocysteine; and the urinary albumin-to-creatinine ratio.

RESULTS

During follow-up (median, 7.4 years), 207 participants died and 169 had a first major cardiovascular event. In Cox proportional-hazards models adjusting for conventional risk factors, the following biomarkers most strongly predicted the risk of death (each biomarker is followed by the adjusted hazard ratio per 1 SD increment in the log values): B-type natriuretic peptide level (1.40), C-reactive protein level (1.39), the urinary albumin-to-creatinine ratio (1.22), homocysteine level (1.20), and renin level (1.17). The biomarkers that most strongly predicted major cardiovascular events were B-type natriuretic peptide level (adjusted hazard ratio, 1.25 per 1 SD increment in the log values) and the urinary albumin-to-creatinine ratio (1.20). Persons with "multimarker" scores (based on regression coefficients of significant biomarkers) in the highest quintile as compared with those with scores in the lowest two quintiles had elevated risks of death (adjusted hazard ratio, 4.08; P<0.001) and major cardiovascular events (adjusted hazard ratio, 1.84; P=0.02). However, the addition of multimarker scores to conventional risk factors resulted in only small increases in the ability to classify risk, as measured by the C statistic.

CONCLUSIONS

For assessing risk in individual persons, the use of the 10 contemporary biomarkers that we studied adds only moderately to standard risk factors.

Association between body mass index and blood pressure across three populations in Africa and Asia

Despite a growing burden of obesity and hypertension in developing countries, there is limited information on the contribution of body mass index (BMI) to blood pressure (BP) in these populations. This study examines the association between BMI and BP in three populations across Africa and Asia. Data on BMI, BP and other background characteristics of study participants were generated using the World Health Organization STEPwise approach to surveillance (STEPS), at three demographic surveillance sites in Ethiopia, Vietnam and Indonesia. BMI and BP increased along the socioeconomic gradient across the three countries. Mean (s.d.) BMI in men varied between 19.41 (2.28) in Ethiopia to 21.17 (2.86) in Indonesia. A high prevalence of overweight/obesity was noted among Indonesian women (25%) and men (10%), whereas low BMI was widely prevalent in Ethiopia and Vietnam, ranging from 33 to 43%. Mean (s.d.) systolic BP (SBP) among men varied between 117.15 (15.35) in Ethiopia to 127.33 (17.80) in Indonesia. The prevalence of hypertension was highest among women (25%) and men (24%) in Indonesia. Mean BP levels increased with increasing BMI. The risk of hypertension was higher among population groups with overweight and obesity (BMI>/=25 kg/m(2)); odds ratio (95% confidence interval); 2.47 (1.42, 4.29) in Ethiopia, 2.67 (1.75, 4.08) in Vietnam and 7.64 (3.88, 15.0) in Indonesia. BMI was significantly and positively correlated with both SBP and DBP in all the three populations, correlation coefficient (r) ranging between 0.23 and 0.27, P<0.01. High BP exists in a background of undernutrition in populations at early stages of the epidemiologic transition.

Ethnicity and diabetic heart disease

Ethnicity is a complex yet important construct and an independent risk factor for diabetic heart disease (DHD) with paramount clinical significance. Clinicians should try to better understand the role of ethnicity through more questions. The risk of DHD is modified by ethnicity through more questions. The risk of DHD is modified by ethnicity, and its management may require a culturally sensitive individualized approach. Findings from Caucasian populations cannot be fully extrapolated to other ethnic groups, thereby emphasizing the importance of future research with ethnicity-based threshold for obesity. Available limited data support the interaction between genetic predisposition, environmental risk, and lifestyle choices and disparities based on ethnicity as the likely cause for ethnic variations in DHD.

Traditional and emerging cardiovascular and renal risk factors: An epidemiologic perspective

Patients with chronic kidney disease (CKD) represent an important segment of the population (7-10%) and, mostly because of the high risk of cardiovascular complications associated with renal insufficiency, detection and treatment of CKD is now a public health priority. Traditional risk factors can incite renal dysfunction and cardiovascular damage as well. As renal function deteriorates, non-traditional risk factors play an increasing role both in glomerular filtration rate (GFR) loss and cardiovascular damage. Secondary analyses of controlled clinical trials suggest that inflammation may be a modifiable risk factor both for cardiac ischemia and renal disease progression in patients with or at risk of coronary heart disease. Homocysteine predicts renal function loss in the general population and cardiovascular events in end-stage renal disease (ESRD), but evidence that this sulfur amino acid is directly implicated in the progression of renal disease and in the high cardiovascular mortality of uremic patients is still lacking. High sympathetic activity and raised plasma concentration of asymmetric dimethylarginine (ADMA) have been associated to reduced GFR in patients with CKD and to cardiovascular complications in those with ESRD but again we still lack clinical trials targeting these risk factors. Presently, the clinical management of CKD patients remains largely unsatisfactory because only a minority of these attain the treatment goals recommended by current guidelines. Thus, in addition to research into new and established risk factors, it is important that nephrologists make the best use of knowledge already available to optimize the follow-up of these patients.

The “Americanisation” of migrants: Evidence for the contribution of ethnicity, social deprivation, lifestyle and life-course processes to the mid-20th century Coronary Heart Disease epidemic in the US

We investigated the contribution of the large-scale immigration of White Europeans into the US between 1850 and 1930 to the timing and extent of the epidemic pattern of heart disease between 1900 and 1980. The analyses are based on data collected through the United States Federal Census from 1850 to the present. The hardcopy historical record confirms that census reports themselves and related monographs were concerned from 1850 with excessive mortality from heart disease of immigrants, particularly of Northern European origin and initially at least, their first-generation native-born children. Our analysis of the electronic database indicates a strong relationship between the percentage of US population foreign born and native born of foreign parentage and age adjusted mortality from heart disease. We identified a lag of 50 years giving the maximum linear correlation coefficient for men (r(2) = 0.92), and for women a shorter lag of 38 years and an earlier decline in Coronary Heart Disease (CHD) rates (r(2) = 0.96). Both the rise and fall of the CHD epidemic over an 80-year period correspond closely to the rise and fall of the foreign population in previous years. For the foreign born only, age adjusted negative binomial general estimated equation (GEE) models calculate the relative risk of dying of heart disease per 10% increase in proportion foreign born. There is an independent influence for men until 1930 and for women throughout the period from 1910 onwards. We conclude there is an impact of immigration on the pattern of the epidemic, mediated through a combination of factors, such as accumulated life-course susceptibility, deprived socio-economic conditions upon arrival, and the enthusiastic uptake of behaviours related to the classic risk factors of smoking, high saturated fat and salt diet. Our analysis provides a more contextualised understanding of the scale and timing of the epidemic of CHD in the US.

Explaining the social gradient in coronary heart disease: comparing relative and absolute risk approaches

STUDY OBJECTIVES

There are contradictory perspectives on the importance of conventional coronary heart disease (CHD) risk factors in explaining population levels and social gradients in CHD. This study examined the contribution of conventional CHD risk factors (smoking, hypertension, dyslipidaemia, and diabetes) to explaining population levels and to absolute and relative social inequalities in CHD. This was investigated in an entire population and by creating a low risk sub-population with no smoking, dyslipidaemia, diabetes, and hypertension to simulate what would happen to relative and social inequalities in CHD if conventional risk factors were removed.

DESIGN, SETTING, AND PARTICIPANTS

Population based study of 2682 eastern Finnish men aged 42, 48, 54, 60 at baseline with 10.5 years average follow up of fatal (ICD9 codes 410-414) and non-fatal (MONICA criteria) CHD events.

MAIN RESULTS

In the whole population, 94.6% of events occurred among men exposed to at least one conventional risk factor, with a PAR of 68%. Adjustment for conventional risk factors reduced relative social inequality by 24%. However, in a low risk population free from conventional risk factors, absolute social inequality reduced by 72%.

CONCLUSIONS

Conventional risk factors explain the majority of absolute social inequality in CHD because conventional risk factors explain the vast majority of CHD cases in the population. However, the role of conventional risk factors in explaining relative social inequality was modest. This apparent paradox may arise in populations where inequalities in conventional risk factors between social groups are low, relative to the high levels of conventional risk factors within every social group. If the concern is to reduce the overall population health burden of CHD and the disproportionate population health burden associated with the social inequalities in CHD, then reducing conventional risk factors will do the job.

Uncovering the determinants of cardiovascular disease among Indigenous people

OBJECTIVE

This paper attempts to delineate an appropriate methodology for research into cardiovascular diseases (CVD) in the context of the Australian Indigenous population.

DESIGN

Our argument proceeds in three main stages of critical analysis of the appropriate literature. First we demonstrate the extremely complex aetiology of CVD and also argue that, in any population, exposure to many of the more important risk factors at an individual or group level is generated through social and behavioural factors whose causation, persistence and reproduction are both complex and multilayered. Secondly, and having established that the aetiology and morbidity of CVD in various populations is a product of a complex and interactive hierarchy of biomedical, social and political processes, we argue that only research methodologies capable of encompassing the complete span of this hierarchy can be expected to generate results which are efficacious as a basis for intervention. Thirdly, and most importantly, we argue that in the Indigenous context a central and essential feature in the development of an appropriate methodology must be to centre Indigenous people themselves as the dominant partner in setting the research agenda and the conduct of research.

RESULTS/CONCLUSIONS

We conclude that an appropriate methodology for the elucidation of the aetiology, and sequelae of CVD in Indigenous people, would go far beyond 'black box' epidemiology, would recognise the essentially social nature of chronic disease by deploying appropriate social theory within a transdisciplinary framework and would centre Indigenous people as the dominant partner in the research process.

Thyroid status, cardiovascular risk, and mortality in older adults

CONTEXT

Previous studies have suggested that subclinical abnormalities in thyroid-stimulating hormone levels are associated with detrimental effects on the cardiovascular system.

OBJECTIVE

To determine the relationship between baseline thyroid status and incident atrial fibrillation, incident cardiovascular disease, and mortality in older men and women not taking thyroid medication.

DESIGN, SETTING, AND PARTICIPANTS

A total of 3233 US community-dwelling individuals aged 65 years or older with baseline serum thyroid-stimulating hormone levels were enrolled in 1989-1990 in the Cardiovascular Health Study, a large, prospective cohort study.

MAIN OUTCOME MEASURES

Incident atrial fibrillation, coronary heart disease, cerebrovascular disease, cardiovascular death, and all-cause death assessed through June 2002. Analyses are reported for 4 groups defined according to thyroid function test results: subclinical hyperthyroidism, euthyroidism, subclinical hypothyroidism, and overt hypothyroidism.

RESULTS

Individuals with overt thyrotoxicosis (n = 4) were excluded because of small numbers. Eighty-two percent of participants (n = 2639) had normal thyroid function, 15% (n = 496) had subclinical hypothyroidism, 1.6% (n = 51) had overt hypothyroidism, and 1.5% (n = 47) had subclinical hyperthyroidism. After exclusion of those with prevalent atrial fibrillation, individuals with subclinical hyperthyroidism had a greater incidence of atrial fibrillation compared with those with normal thyroid function (67 events vs 31 events per 1000 person-years; adjusted hazard ratio, 1.98; 95% confidence interval, 1.29-3.03). No differences were seen between the subclinical hyperthyroidism group and euthyroidism group for incident coronary heart disease, cerebrovascular disease, cardiovascular death, or all-cause death. Likewise, there were no differences between the subclinical hypothyroidism or overt hypothyroidism groups and the euthyroidism group for cardiovascular outcomes or mortality. Specifically, individuals with subclinical hypothyroidism had an adjusted hazard ratio of 1.07 (95% confidence interval, 0.90-1.28) for incident coronary heart disease.

CONCLUSION

Our data show an association between subclinical hyperthyroidism and development of atrial fibrillation but do not support the hypothesis that unrecognized subclinical hyperthyroidism or subclinical hypothyroidism is associated with other cardiovascular disorders or mortality.

A Scaled Sample Space Cube Used to Illustrate Attributable Fractions

A three-dimensional graphic method is proposed for displaying the association structure between multiple explanatory variables and their relation to a categorical response. The method combines the techniques of mosaic displays and scaled Venn diagrams, and is especially useful for illustrating attributable fractions in epidemiology. The primary purpose is to show the reduction of disease risk in a population if the joint exposure distribution or the conditional risk function is modified, and the method can be extended to illustrate the potential effects of successive removal of exposures on the overall risk of disease. The scaled sample space cube may be used for communicating the difficult concept of attributable fraction to statisticians, the medical community and the general public in an easily understandable way. Demonstrations of the method use theoretical models as well as data from the Hordaland study on the effect of smoking and occupational exposure on obstructive lung disease. Also, the general principle of adding a third dimension to a mosaic display, instead of using shading or colouring, to show an attribute of a cell in a multiway contingency table, can be helpful for other purposes, as in residual analysis of a loglinear model fitting.

Association between platelet P2Y12 haplotype and risk of cardiovascular events in chronic coronary disease

INTRODUCTION

A positive association was recently described between P2Y12 platelet receptor H1 and H2 haplotypes and peripheral artery disease. We tested the described P2Y12 receptor haplotypes in a group of patients with coronary artery disease.

STUDY DESIGN AND METHODS

The P2Y12 platelet receptor H1 and H2 haplotypes was tested in a group of 540 patients enrolled in the Medical, Angioplasty, or Surgery Study II (MASS II), a randomized trial comparing treatments for patients with coronary artery disease (CAD) and preserved left ventricular function. After a 3-year follow-up period, the incidence of the composite end point of cardiac death, myocardial infarction, and refractory angina requiring revascularization was determined in the H1/H1, H1/H2 and H2/H2 haplotype groups. We used Student's t-test and the chi-square test to analyze the differences among groups and Kaplan-Meier method to calculate survival curves. Risk was assessed with the use of a Cox proportional-hazards model.

RESULTS

The frequency of haplotypes among studied patients were 410 (75.9%) H1/H1, 119 (22.0%) H1/H2 and 11 (2.1%) H2/H2. The baseline clinical characteristics, mean clinical follow-up time and received treatment of each genotype group were similar. We did not disclose any association between haplotype groups regarding the incidence of any of the studied cardiovascular end-points.

CONCLUSION

This is the first report studying the association of P2Y12 platelet receptor H1 and H2 haplotype and cardiovascular events. Our findings do not provide evidence for a strong association between H1/H1 and H1/H2 haplotypes and a increased risk of cardiovascular events in a population with CAD. Future works should address the role of the H2/H2 haplotype as a genetic marker for cardiovascular events.

Primary prevention of coronary artery disease among middle aged men in Prague: Twenty-year follow-up results

BACKGROUND

Coronary artery disease (CAD) represents the most common cause of morbidity and mortality in the Czech Republic. The aim of this study is to analyze long-term cardiovascular diseases (CVD) mortality, identify predictors of outcome and to validate the Framingham risk function in men from the Czech Republic.

DESIGN AND METHODS

A 20-year primary prevention study of atherosclerosis risk factors in 1417 men from Prague aged 38-53 years was launched in 1975 (STULONG).

RESULTS

When analyzing CVD mortality, heavy smokers had hazard higher than non-smokers and light smokers (p < 0.0001); hypertensives higher than normotensives (p < 0.0001); men with hypercholesterolemia higher than those with normal cholesterol (p = 0.0432), and university-educated men lower than elementary-educated men (p = 0.0006). In 1980-1984, the age specific mortality from CVD in men from STULONG was higher (p = 0.0132) than in the Czech Republic, in 1985-1994 insignificantly lower. The Framingham risk function underestimated the absolute 10-year risk of CAD across the quintile of the risk (p < 0.0001), with 63% discrimination.

CONCLUSION

In STULONG, the mortality from CVD was significantly associated with known risk factors (hypertension, smoking, hypercholesterolemia, education); the Framingham risk function underestimated the absolute 10-year risk of CAD.

Knowledge and perception of guidelines and secondary prevention of coronary heart disease among general practitioners and internists. Results from a physician survey in Germany

AIMS

This study investigated knowledge and perception of guidelines in secondary prevention of coronary heart disease and the impact of guideline knowledge on treatment practices in coronary patients among primary care physicians.

DESIGN AND METHODS

A representative questionnaire survey was performed in 2002-2003 among all 1023 general practitioners and office-based internists in the Region of Münster, Germany. The survey instrument contained questions on knowledge and attitudes toward guidelines, risk factors and treatment practices in secondary prevention of coronary heart disease.

RESULTS

In total, 681 (66.6%) physicians participated. Seventy percent of physicians reported knowledge of at least one guideline. Participants expressed mainly positive attitudes toward guidelines but also reported important barriers to their implementation such as lack of reimbursement. Only 63 and 32%, respectively, reported to start antihypertensive and lipid-lowering treatment according to guidelines. Physicians reporting guideline knowledge were more likely to initiate lipid-lowering treatment of elevated low-density lipoprotein (LDL)-cholesterol [odds ratio (OR) 2.3; 95% confidence interval (CI) 1.5-3.5], to intensively advise overweight patients (OR 1.5; 95% CI 1.0-2.5), to make use of nicotine replacement therapy or cessation courses in smoking patients (OR 1.7; 95% CI 1.2-2.4), and to comply with an overall measure of guideline adherence (OR 1.8; 95% CI 1.1-2.8).

CONCLUSIONS

In this study, guideline knowledge led to improved cardiovascular risk factor treatment among GPs and internists. Many physicians, however, do not treat coronary patients according to evidence-based guidelines. Further dissemination of guidelines and educational efforts are essential to improve secondary prevention of coronary heart disease.

Joint Effects of Systolic Blood Pressure and Serum Cholesterol on Cardiovascular Disease in the Asia Pacific Region

BACKGROUND

Although interest in multifactorial interventions for cardiovascular disease is increasing, data on the strength and shape of the joint effects of blood pressure and cholesterol levels on the risk of cardiovascular disease are scarce, confined primarily to coronary heart disease (CHD) mortality in early middle-aged Western populations.

METHODS AND RESULTS

This analysis included 29 cohorts from Asia (78% of the total 380,216 participants) and 7 from Australia and New Zealand, with a total of 2,547,447 person-years of observation. Stratified time-dependent Cox proportional-hazards analyses were used to regress time until first event against baseline systolic blood pressure (SBP) and total cholesterol levels. A total of 3079 CHD and 4247 stroke events occurred; stroke subtypes were confirmed by CT, MRI, or necropsy in 1471 (35%) stroke events. Usual values of SBP were strongly linearly associated with ischemic stroke, hemorrhagic stroke, and CHD. The slope of the association with SBP became steeper with decreasing levels of cholesterol for ischemic stroke (P=0.007) and CHD (P< or =0.0001). For example, for the cholesterol groups of <4.75, 4.75 to 5.49, 5.50 to 6.24, and > or =6.25 mmol/L, each 10-mm Hg-higher systolic pressure was associated with 34% (95% CI, 30% to 37%), 28% (95% CI, 21% to 35%), 25% (95% CI, 18% to 32%), and 21% (95% CI, 13% to 27%) higher CHD risk, respectively. Adjustments for other leading cardiovascular risk factors made no appreciable differences in these results.

CONCLUSIONS

In Asia-Pacific populations, there are hazards of increasing SBP at all cholesterol levels and hazards of increasing cholesterol at all levels of SBP, but the associations of SBP with CHD risk and ischemic stroke risk are slightly steeper among those with low cholesterol levels. The joint effects of SBP and total cholesterol on cardiovascular disease seem consistent across various Western and Asian populations.

Prevalence of conventional risk factors in Jordanians with coronary heart disease: the Jordan Hyperlipidemia and Related Targets Study (JoHARTS)

BACKGROUND

The prevalence of the major conventional cardiovascular risk factors - cigarette smoking, diabetes mellitus, hypertension, and dyslipidemia - among coronary heart disease (CHD) patients in the Middle East has not been studied extensively.

METHODS AND RESULTS

The Jordan Hyperlipidemia And Related Targets Study (JoHARTS) evaluated the prevalence of the 4 conventional risk factors in 5000 individuals including 1692 (34%) women. CHD was present in 1534 (31%) individuals (1202 men and 332 women). Among CHD patients, at least one risk factor was present in the majority of men (95%) and women (96%). Compared with women who had CHD, men had significantly higher prevalence of smoking (45% vs. 11%, p < 0.0001) and low levels of high-density lipoprotein cholesterol (60% vs. 39%, p < 0.0001), and lower prevalence of diabetes (40% vs. 64%, p < 0.0001), hypertension (38% vs. 63%, p < 0.0001), and hypercholesterolemia (19% vs. 27%, p = 0.003). Diabetes was more prevalent among men and women with CHD than men and women without CHD (40% vs. 18% for men, and 64% vs. 24% for women p < 0.0001). Similarly, smoking was more prevalent in men and women with CHD than those without CHD (45% vs. 32% for men, and 11% vs. 7%, p < 0.0001). Low levels of high-density lipoprotein cholesterol were also more prevalent in men with CHD than those without CHD (60% vs. 51%, p < 0.001) and among women with CHD than those without CHD (39% vs. 24%, p = 0.0001). Prevalence rates of hypertension, hypercholesterolemia, and hypertriglyceridemia were not different among individuals with or without CHD.

CONCLUSION

These results further challenge claims that patients with CHD commonly lack conventional risk factors. The great majority (>95%) of CHD patients studied have at least one risk factor. Detection, evaluation and management of these factors are essential steps to control CHD in the region.

Behavioral science at the crossroads in public health: extending horizons, envisioning the future

The social and behavioral sciences are at a crossroads in public health. In this paper, we attempt to describe a path toward the further integration of the natural and behavioral sciences with respect to the study of behavior and health. Three innovations are proposed. First, we extend and modify the "stream of causation" metaphor along two axes: time, and levels of nested systems of social and biological organization. Second, we address the question of whether 'upstream' features of social context are causes of disease, fundamental or otherwise. Finally, we propose the concept of a risk regulator to advance the study of behavior and health in populations. To illustrate the potential of these innovations, we develop a multilevel framework for the study of health behaviors and obesity in social and biological context.

Race/ethnicity, income, major risk factors, and cardiovascular disease mortality

OBJECTIVES

We explored differences between Black and White men for cardiovascular disease (CVD) mortality across major risk factor levels.

METHODS

Major CVD risk factors were measured among 300,647 White and 20,223 Black men aged 35 to 57 years who were screened for the Multiple Risk Factor Intervention Trial (MRFIT). Hazard ratios for CVD deaths for Black and White men over 25 years of follow-up were calculated for subgroups stratified according to risk factor levels.

RESULTS

CVD was responsible for 2518 deaths among Black men and 30,772 deaths among White men. The age-adjusted Black-to-White CVD hazard ratio was 1.35 (95% confidence interval [CI]=1.29, 1.40); the risk- and income-adjusted ratio was 1.05 (95% CI=1.01, 1.10). CVD mortality rates were dramatically lower in cases of favorable risk profiles. However, fully adjusted Black-to-White CVD hazard ratios within groups at low, intermediate, high, and very high levels of overall risk were 1.76, 1.20, 1.10, and 0.94, respectively. Similar gradients were evident for individual risk factors.

CONCLUSIONS

Higher CVD mortality rates among Black men were largely mediated by risk factors and income. These data underscore the need for sustained primordial risk factor prevention among Black men.

Clinical Research in Primary Stroke Prevention: Needs, Opportunities, and Challenges

Most ( approximately 70%) of strokes are first-ever strokes, and hence to substantially reduce the neurological burden, primary prevention is crucial. Here, highlights of the National Institute of Neurological Disorders and Stroke workshop "Stroke Risk Assessment and Future Stroke Primary Prevention Trials" held January 12-13, 2004 are summarized. The Workshop discussions focused on stroke risk assessment; the high-risk vs. population-based approaches to primary prevention; desirable characteristics of candidate treatments and potential novel treatments, such as the 'polypill'; subclinical disease as risk assessment tool and as surrogate outcome, and methodological issues in stroke primary prevention trials. The importance of assessing cognitive decline as an important consequence of covert and overt vascular injury of the brain was emphasized. The scientific or logistic barriers to stroke primary prevention trials are challenging, but are not insurmountable.

Beyond reproduction: Women's health in today's developing world

BACKGROUND

The concept of women's health is tethered strongly to reproductive health. At present, international attention and resources are focused on obstetric events and, recently, HIV/AIDS because of the significance of these problems in the least developed nations. This limited concept of women's health, however, is decreasingly relevant to the global community, and needs to be revisited in the light of decreasing fertility and increasing life expectancy in many countries where it was previously applicable. It should be expanded to embrace the full spectrum of health experienced by women, and preventive and remedial approaches to the major conditions that afflict women. Allocation of health service resources should be aligned with the epidemiological realities of these threats to women's health.

METHODS

Cause of death data for women aged 15-34 years and 35-44 years were examined for nine less developed countries. Deaths associated with pregnancy and child birth, and HIV were compared with deaths due to three chronic disease categories (cancer, cardiovascular disease, and diabetes). The women's health research literature for developing countries appearing in the American Journal of Public Health and British Medical Journal was also examined.

RESULTS

In seven out of the nine countries, among women aged 15-34 years, chronic diseases caused over 20% of deaths, while reproductive causes and HIV together accounted for approximately 10% of deaths, in all countries except in India. Among women aged 35-44 years, in all but India, chronic diseases accounted for over four times the deaths attributable to reproductive causes and HIV. The causes of death were not related to the level of development in these countries as measured by GNI PPP. Papers pertaining to women's health published in public health and medical research journals focused principally on reproduction.

CONCLUSIONS

Extending the definition of women's health to include a concern for chronic diseases is critical if the needs of women in less developed nations are to be met. In less developed countries, chronic disease is the most important cause of female death even during childbearing years and for women with young families. Development agencies and private philanthropy must begin to fund the studies that will further refine our understanding of the role of chronic diseases in women's health in the developing world.

A life course approach to chronic disease epidemiology

A life course approach to chronic disease epidemiology uses a multidisciplinary framework to understand the importance of time and timing in associations between exposures and outcomes at the individual and population levels. Such an approach to chronic diseases is enriched by specification of the particular way that time and timing in relation to physical growth, reproduction, infection, social mobility, and behavioral transitions, etc., influence various adult chronic diseases in different ways, and more ambitiously, by how these temporal processes are interconnected and manifested in population-level disease trends. In this review, we discuss some historical background to life course epidemiology and theoretical models of life course processes, and we review some of the empirical evidence linking life course processes to coronary heart disease, hemorrhagic stroke, type II diabetes, breast cancer, and chronic obstructive pulmonary disease. We also underscore that a life course approach offers a way to conceptualize how underlying socio-environmental determinants of health, experienced at different life course stages, can differentially influence the development of chronic diseases, as mediated through proximal specific biological processes.

Lifestyle and cardiovascular disease in middle-aged British men: the effect of adjusting for within-person variation

AIMS

To examine the effect that within-person variation has on the estimated risk associations between cigarette smoking, physical inactivity, and increased body mass index (BMI) and the development of cardiovascular disease (CVD) in middle-aged British men.

METHODS AND RESULTS

In total, 6452 men aged 40-59 with no prior evidence of CVD were followed for major CVD events (fatal/non-fatal myocardial infarction or stroke) and all-cause mortality over 20 years; lifestyle characteristics were ascertained at regular points throughout the study. A major CVD event within the first 20 years was observed in 1194 men (18.5%). Use of baseline assessments of cigarette smoking and physical activity in analyses resulted in underestimation of the associations between average cumulative exposure to these factors and major CVD risk. After correction for within-person variation, major CVD rates were over four times higher for heavy smokers (> or =40 cigarettes/day) compared with never smokers and three times higher for physically inactive men compared with moderately active men. Major CVD risk increased by 6% for each 1 kg/m(2) increase in usual BMI. If all men had experienced the risk levels of the men who had never regularly smoked cigarettes, were moderately active, and had a BMI of < or =25 kg/m(2) (6% of the population), 66% of the observed major CVD events would have been prevented or postponed (63% before adjustment for within-person variation). Adjustment for a range of other risk factors had little effect on the results. Similar results were obtained for all-cause mortality.

CONCLUSION

Failure to take account of within-person variation can lead to underestimation of the importance of lifestyle characteristics in determining CVD risk. Primary prevention through lifestyle modification has a great preventive potential.

Increasing trends of acute myocardial infarction in Spain: the MONICA-Catalonia Study

AIMS

To assess coronary mortality and morbidity secular trends in Spain.

METHODS AND RESULTS

Acute coronary events occurring in both sexes at ages 35-74 years between 1985 and 1997, were monitored in a geographical area of Catalonia, through a population-based registry. Information was collected from annual discharge lists of 78 hospitals and from death certificates, and validated following the methods and quality control of the World Health Organization MONItoring Trends and Determinants in CArdiovascular Disease Project (MONICA). Registration included 19 119 valid events (14 221 in men, 4898 in women) of which 30% were fatal and 41% were definite acute myocardial infarctions. Average attack rates were 315 per 100 000 (95% CI 300-329) and 80 (75-86) in men and women, respectively. Incidence (first-ever event) rates were 209 (194-224) and 56 (52-60) per 100 000. Attack rates increased annually by 2.1% (0.3-4.1) and 1.8% (-0.9 to +4.6). Average 28-day case fatality was 46% (44-47) in men decreasing significantly by 1.4 and 53% (51-55) in women with no change. Fatal trends remained stable. Nationwide morbidity statistics showed similar trends.

CONCLUSION

Acute coronary syndromes are rising in Spanish men.

Cardiovascular risk assessment and management in developing countries

Causes of the burgeoning cardiovascular epidemic in developing countries (DC) are known. Whilst there are many prevention strategies and policies demonstrated to be effective in reducing the trends of cardiovascular disease in developed countries, applying them in DCs is challenging and complex. To utilize resources efficiently, two key decisions have to be made by policy makers in all DCs. The first is to decide on the appropriate mix of population and high-risk interventions. The second is to determine the threshold for implementing high-risk interventions. In making such decisions, due consideration needs to be given to scientific evidence, affordability, sustainability, opportunity costs, and social and political realities. High-risk approaches can be made cost-effective if individuals that are most likely to benefit from treatment can be identified through risk stratification systems. Although several such risk prediction systems are available, they have limited applicability to non-Western populations. Further, health systems in DCs do not have basic infrastructure facilities to support resource intensive risk prediction tools, particularly in primary healthcare. The World Health Organization has developed a flexible cardiovascular disease risk management package that is implemented in a range of less resourced settings. A risk prediction tool that enables more accurate prediction of cardiovascular risk in DCs is in development.