Asthma and incident cardiovascular disease: the Atherosclerosis Risk in Communities Study.

BACKGROUND: A possible association between asthma and cardiovascular disease has been described in several exploratory studies. METHODS: The association of self-reported, doctor diagnosed asthma and incident cardiovascular disease was examined in a biracial cohort of 45-64 year old adults (N = 13501) followed over 14 years. RESULTS: Compared with never having asthma, the multivariate adjusted hazard ratio (HR) of stroke (n = 438) was 1.50 (95% CI 1.04 to 2.15) for a baseline report of ever having asthma (prevalence 5.2%) and 1.55 (95% CI 0.95 to 2.52) for current asthma (prevalence 2.7%). The relative risk of stroke was 1.43 (95% CI 1.03 to 1.98) using a time dependent analysis incorporating follow up reports of asthma. Participants reporting wheeze attacks with shortness of breath also had greater risk for stroke (HR = 1.56, 95% CI 1.18 to 2.06) than participants without these symptoms. The multivariate adjusted relative risk of coronary heart disease (n = 1349) was 0.87 (95% CI 0.66 to 1.14) for ever having asthma, 0.69 (95% CI 0.46 to 1.05) for current asthma at baseline, and 0.88 (95% CI 0.69 to 1.11) using the time dependent analysis. CONCLUSIONS: Asthma may be an independent risk factor for incident stroke but not coronary heart disease in middle aged adults. This finding warrants replication and may motivate a search for possible mechanisms that link asthma and stroke.

Arterial distensibility and physical activity in the ARIC study.

PURPOSE: Arterial distensibility decreases with age. This decrease may be associated with the initiation and/or progression of hypertension and atherosclerosis and may be attenuated by positive lifestyle habits, including habitual physical activity. We tested the hypothesis that self-reported sport, leisure, and work physical activity is associated with greater arterial distensibility (i.e., carotid artery pulsatile diameter changes). METHODS: The Atherosclerosis Risk in Communities (ARIC) study assessed left common carotid arterial diameters and intimal-medial wall thickness (IMT) using B-mode ultrasound techniques, in 10,644 African-American and white men and women aged 45-64 yr and free of cardiovascular disease. RESULTS: Work activity, but not sports or leisure activity, was weakly associated with greater arterial distensibility in an ANCOVA model adjusted for blood pressure and other covariates (diastolic arterial diameter, pulse pressure, pulse pressure squared, age, race, sex, smoking, dietary fat intake, height, education, and clinical center) (P for linear trend = 0.03). Vigorous sports activity was weakly positively associated with arterial distensibility (arterial diameter change (mean +/- SE in mm) 0.42 +/- 0.004 vs 0.41 +/- 0.002 for the 12.7% of participants reporting any vs no vigorous activity, P = 0.02), and this association was not attenuated by adjustment for IMT, body mass index, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, or diabetes. Repeated analyses with traditional arterial stiffness indices showed similar findings for vigorous but not work activity. CONCLUSION: In contrast to several smaller studies, these findings do not support the hypothesis that habitual physical activity has a strong, consistent positive effect on arterial distensibility.

Coronary heart disease prediction from lipoprotein cholesterol levels, triglycerides, lipoprotein(a), apolipoproteins A-I and B, and HDL density subfractions: The Atherosclerosis Risk in Communities (ARIC) Study.

BACKGROUND: Despite consensus on the need for blood cholesterol reductions to prevent coronary heart disease (CHD), available evidence on optimal cholesterol levels or the added predictive value of additional lipids is sparse. METHODS AND RESULTS: After 10 years follow-up of 12 339 middle-aged participants free of CHD in the Atherosclerosis Risk in Communities Study (ARIC), 725 CHD events occurred. The lowest incidence was observed in those at the lowest LDL cholesterol (LDL-C) quintile, with medians of 88 mg/dL in women and 95 mg/dL in men, and risk accelerated at higher levels, with relative risks (RRs) for the highest quintile of 2.7 in women and 2.5 in men. LDL-C, HDL-C, lipoprotein(a) [Lp(a)], and in women but not men, triglycerides (TG) were all independent CHD predictors, providing an RR, together with blood pressure, smoking, and diabetes, of 13.5 in women and 4.9 in men. Lp(a) was less significant in blacks than whites. Prediction was not enhanced by HDL-C density subfractions or apolipoproteins (apo) A-I or B. Despite strong univariate associations, apoB did not contribute to risk prediction in subgroups with elevated TG, with lower LDL-C, or with high apoB relative to LDL-C. CONCLUSIONS: Optimal LDL-C values are <100 mg/dL in both women and men. LDL-C, HDL-C, TG, and Lp(a), without additional apolipoproteins or lipid subfractions, provide substantial CHD prediction, with much higher RR in women than men.

Neighborhood of residence and incidence of coronary heart disease.

BACKGROUND: Where a person lives is not usually thought of as an independent predictor of his or her health, although physical and social features of places of residence may affect health and health-related behavior. METHODS: Using data from the Atherosclerosis Risk in Communities Study, we examined the relation between characteristics of neighborhoods and the incidence of coronary heart disease. Participants were 45 to 64 years of age at base line and were sampled from four study sites in the United States: Forsyth County, North Carolina; Jackson, Mississippi; the northwestern suburbs of Minneapolis; and Washington County, Maryland. As proxies for neighborhoods, we used block groups containing an average of 1000 people, as defined by the U.S. Census. We constructed a summary score for the socioeconomic environment of each neighborhood that included information about wealth and income, education, and occupation. RESULTS: During a median of 9.1 years of follow-up, 615 coronary events occurred in 13,009 participants. Residents of disadvantaged neighborhoods (those with lower summary scores) had a higher risk of disease than residents of advantaged neighborhoods, even after we controlled for personal income, education, and occupation. Hazard ratios for coronary events in the most disadvantaged group of neighborhoods as compared with the most advantaged group--adjusted for age, study site, and personal socioeconomic indicators--were 1.7 among whites (95 percent confidence interval, 1.3 to 2.3) and 1.4 among blacks (95 percent confidence interval, 0.9 to 2.0). Neighborhood and personal socioeconomic indicators contributed independently to the risk of disease. Hazard ratios for coronary heart disease among low-income persons living in the most disadvantaged neighborhoods, as compared with high-income persons in the most advantaged neighborhoods were 3.1 among whites (95 percent confidence interval, 2.1 to 4.8) and 2.5 among blacks (95 percent confidence interval, 1.4 to 4.5). These associations remained unchanged after adjustment for established risk factors for coronary heart disease. CONCLUSIONS: Even after controlling for personal income, education, and occupation, we found that living in a disadvantaged neighborhood is associated with an increased incidence of coronary heart disease.

Occupational hierarchy, economic sector, and mortality from cardiovascular disease among men and women. Findings from the National Longitudinal Mortality Study.

PURPOSE: Although socioeconomic position has been identified as a determinant of cardiovascular disease among employed men and women in the U.S., the role of economic sector in shaping this relationship has yet to be examined. We sought to estimate the combined effects of economic sector-one of the three major sectors of the economy: finance, government and production-and socioeconomic position on cardiovascular mortality among employed men and women. METHODS: Approximately 375,000 men and women 25 years of age or more were identified from selected Current Population Surveys between 1979 and 1985. These persons were followed for cardiovascular mortality through use of the National Death Index for the years 1979 through 1989. RESULTS: In men, the lowest cardiovascular mortality was found for professionals in the finance sector (76/100,000 person/years). The highest cardiovascular mortality was found among male non-professional workers in the production sector (192/100,000 person years). A different pattern was observed among women. Professional women in the finance sector had the highest rates of cardiovascular mortality (133/100,000 person years). For both men and women, the professional/non-professional gap in cardiovascular mortality was lower in the government sector than in the production and finance sectors. These associations were strong even after adjustment for age, race and income. CONCLUSIONS: Characteristics of government, finance and production work differentially influence the risk of cardiovascular disease mortality. Men, women, professionals and non-professionals experience this risk differently.

Validation of death certificate diagnosis for coronary heart disease: the Atherosclerosis Risk in Communities (ARIC) Study.

The validity of the death certificate in identifying coronary heart disease deaths was evaluated using data from the community surveillance component of the Atherosclerosis Risk in Communities Study (ARIC). Deaths in the four ARIC communities of Forsyth Co., NC; Jackson, MS; Minneapolis, MN; and Washington Co., MD were selected based on underlying cause of death codes as determined by the rules of the ninth revision of the International Classification of Diseases (ICD-9). Information about the deaths was gathered through informant interviews, physician or coroner questionnaires, and medical record abstraction, and was used to validate the cause of death. Sensitivity, specificity, and positive predictive value of the death certificate classification of CHD death (ICD-9 codes 410-414 and 429.2) were estimated by comparison with the validated cause of death based on physician review of all available information. Results from 9 years of surveillance included a positive predictive value 0.67 (95% CI 0.66-0.68), sensitivity of 0.81 (95% CI 0.79-0.83), and a false-positive rate (1-specificity) of 0.28 (95% CI 0.26-0.30). Comparing CHD deaths as defined by the death certificate with validated CHD deaths indicated that the death certificate overestimated CHD mortality by approximately 20% in the ARIC communities. Within subgroups, death certificate overestimation was reduced with advancing age (up to age 74), was consistent over time, was not dependent on gender, and exhibited considerable variation among communities.

Apolipoprotein A-1 predicts coronary heart disease only at low concentrations of high-density lipoprotein cholesterol: an epidemiological study of Japanese-Americans.

Conventional epidemiological and clinical studies of apolipoprotein A-1 and high-density lipoprotein-cholesterol have demonstrated, when examined jointly, that high-density lipoprotein is a better predictor of coronary heart disease. This strategy does not take into account known lipid metabolic relationships. A statistical approach that takes into account apolipoprotein A-1 being a constituent of the high-density lipoprotein particle is more appropriate. Among 1,177 Japanese-American men of the Honolulu Heart Program cohort free of disease at baseline (1980-1982), 182 new coronary heart disease cases developed over a 12-year follow-up period. After removing the linear relationship with high-density lipoprotein-cholesterol, a relative measure of apoliprotein A-1 concentration was derived. Based on joint conditions of "low" and "high" relative apoliprotein A-1 concentration and < or =40 and >40 mg/dl for the high-density lipoprotein-cholesterol distribution, four groupings were created. Among relative joint groupings of high/< or =40, low/< or =40, high/>40, and low/>40, respectively, the 12-year coronary heart disease incidence varied from 28.6, 18.2, 8.3, to 11.7 cases per 1,000 person-years. A test of statistical interaction was significant (P=0.028). Additional analyses revealed coronary heart disease cases were more likely among men with triglycerides > 190 mg/dl. Observed patterns of relationships among relative apoliprotein A-1 level, high-density lipoprotein cholesterol, and triglycerides with incident coronary heart disease are consistent with patterns noted in clinical, laboratory, and transgenic animal research more capable of elucidating mechanisms of disease causation. This epidemiological study suggests similar mechanisms may be operating at a population level, and may contribute to the public health burden of coronary heart disease.

A prospective study of cytomegalovirus, herpes simplex virus 1, and coronary heart disease: the atherosclerosis risk in communities (ARIC) study.

BACKGROUND: Conflicting evidence exists implicating infectious disease in the pathological processes leading to coronary heart disease (CHD). The objective of this article is to describe the relationship of previous infection with cytomegalovirus (CMV) and herpes simplex virus 1 to incident CHD in a population-based cohort study. METHODS: Using a nested case-cohort design from the Atherosclerosis Risk in Communities Study, antibody levels to CMV and herpes simplex virus 1 were determined in serum samples that had been frozen at the baseline examination in participants free of CHD. Determinations were made in those who developed incident CHD (n=221) during follow-up of up to 5 years from baseline and in a stratified random sample of all participants (n=515). RESULTS: The population with the highest antibody levels of CMV (approximately the upper 20%) showed an increased relative risk (RR) of CHD of 1.76 (95% confidence interval, 1.00-3.11), adjusting for age, sex, and race. After adjustment for additional covariates of hypertension, diabetes, years of education, cigarette smoking, low-density lipoprotein and high-density lipoprotein cholesterol levels, and fibrinogen level, the RR increased slightly. Based on a priori hypotheses, the RR of CHD at the highest antibody levels in individuals with diabetes was particularly large but with wide confidence intervals (RR, 9.2; 95% confidence interval, 1.8-47.0), and the interaction between high levels of antibody to CMV and diabetes was statistically significant (P=.05). There was no association of CHD with the highest herpes simplex virus 1 antibody levels (adjusted RR, 0.77; 95% confidence interval, 0.36-1.62). CONCLUSIONS: High levels of CMV antibodies are significantly associated with incident CHD. Infection with CMV, particularly in more susceptible disease states such as diabetes, may be an important risk factor for CHD.

Marital status and mortality: the national longitudinal mortality study.

PURPOSE: To examine the effect of marital status (married, widowed, divorced/separated, and never-married) on mortality in a cohort of 281,460 men and women, ages 45 years and older, of black and white races, who were part of the National Longitudinal Mortality Study (NLMS). METHODS: Major findings are based on assessments of estimated relative risk (RR) from Cox proportional hazards models. Duration of bereavement for the widowed is also estimated using the Cox model. RESULTS: For persons aged 45-64, each of the non-married groups generally showed statistically significant increased risk compared to their married counterparts (RR for white males, 1.24-1.39; white females, 1.46-1.49; black males, 1.27-1.57; and black females, 1. 10-1.36). Older age groups tended to have smaller RRs than their younger counterparts. Elevated risk for non-married females was comparable to that of non-married males. For cardiovascular disease mortality, widowed and never-married white males ages 45-64 showed statistically significant increased RRs of 1.25 and 1.32, respectively, whereas each non-married group of white females showed statistically significant increased RRs from 1.50 to 1.60. RRs for causes other than cardiovascular diseases or cancers were high (for white males ages 45-64: widowed, 1.85; divorced/separated, 2.15; and never-married, 1.48). The importance of labor force status in determining the elevated risk of non-married males compared to non-married females by race is shown. CONCLUSIONS: Each of the non-married categories show elevated RR of death compared to married persons, and these effects continue to be strong after adjustment for other socioeconomic factors.

Blood pressure and menopausal transition: the Atherosclerosis Risk in Communities study (1987-95).

OBJECTIVE: Blood pressure changes during menopausal transition have not been studied previously using a biracial sample. We investigated whether menopausal transition was associated with change in blood pressure in African-American or white women. DESIGN, SETTING AND PARTICIPANTS: The prospective multicenter study, the Atherosclerosis Risk In Communities (ARIC) Study (1987-95) was utilized. Included were never-users of hormone replacement therapy (3,800 women, 44% of the original sample). MAIN OUTCOME MEASURE: Changes in blood pressure were adjusted for baseline age and body mass index, baseline blood pressure, antihypertensive use, ARIC field center and weight change. The menopausal transition group was compared to the non-transition group, separately, by ethnicity. RESULTS: Women undergoing the menopausal transition did not differ significantly in regard to systolic blood pressure change [5.2, 95% confidence interval (CI) 4.0-6.4] from non-transitional women (4.6, 95% CI 4.0-5.2); adjustment for age, baseline systolic blood pressure and other factors did not alter this finding. Transitional women had significantly less diastolic blood pressure change (-0.5, 95% CI -1.1 to 0.2) than non-transitional women (-2.0, 95% CI -2.4 to -1.7, P= 0.000) but, after adjustment for other covariates, the result was not significant African-American women had significantly (P= 0.003) higher systolic blood pressure change compared to white women, but this difference became non-significant (P= 0.21) after restricting the sample to women younger than 55 years of age. Interactions between menopausal transition and ethnicity were not significant, either in systolic blood pressure or diastolic blood pressure change. CONCLUSION: Menopausal transition is not associated with significant blood pressure change in African-American or white women.

Trends in plasma cholesterol levels in the atherosclerosis risk in communities (ARIC) study.

BACKGROUND: Data from the Atherosclerosis Risk in Communities (ARIC) cohort study were examined both cross-sectionally and intraindividually to confirm recent findings from population-based studies showing a decline in total cholesterol (TC) levels in the United States. METHODS: For the cross-sectional analysis, mean plasma TC levels from 15,792 participants aged 45-64 at baseline visit, and who were selected randomly from four U.S. communities, were examined for each year covered by the first cohort visit (1987, 1988, and 1989). Ninety-three percent of the cohort participants returned for the follow-up visit (1990, 1991, and 1992), and were included in the assessment of intraindividual TC trends. RESULTS: Both mean TC and prevalence of hypercholesterolemia (defined as plasma cholesterol concentration >/=240 mg/dl) consistently declined over the 3 years covered by visit 1 for all age-gender-race groups. For 1987, 1988, and 1989, mean TC values (mg/dl) were, respectively, 220.3, 216.7, and 214.1 (annual average change, -1.4%, P < 0.001). For these same years, hypercholesterolemia prevalence rates were 30. 0, 27.8, and 25.3% (annual average change, -7.8%, P < 0.001). The mean plasma TC also decreased within individuals between the two visits across race, gender, and age decade categories. With the exception of black men, this decline was more marked for older than younger subjects, but no consistent differences were seen between the racial groups. However, in whites, decreases were greater for men than for women. Expected results were seen when these changes were correlated with changes in cardiovascular risk factors between the two visits. CONCLUSION: The current study results are consistent with those of previous studies, and confirm the notion that preventive programs appear to be effective in reducing mean population TC levels.

Respondent bias in the collection of alcohol and tobacco data in American Indians: the Strong Heart Study.

This study addresses the impact of assessment method (interviewer-administered questionnaire vs. self-administered questionnaire) and interviewers demographic characteristics (gender, ethnicity, and residency) on responses to alcohol and tobacco questions. The study population included 1,522 men and women aged 45 to 74 from the Dakota Center of the Strong Heart Study (SHS), a multi-center study of cardiovascular disease in American Indians. Assessment method effects were greater for alcohol than tobacco but did not differ by interviewer characteristics.

The relation of residential segregation to all-cause mortality: a study in black and white.

OBJECTIVES: This study investigated the influence of an aggregate measure of the social environment on racial differences in all-cause mortality. METHODS: Data from the National Longitudinal Mortality Study were analyzed. RESULTS: After adjustment for family income, age-adjusted mortality risk increased with increasing minority residential segregation among Blacks aged 25 to 44 years and non-Blacks aged 45 to 64 years. In most age/race/gender groups, the highest and lowest mortality risks occurred in the highest and lowest categories of residential segregation, respectively. CONCLUSIONS: These results suggest that minority residential segregation may influence mortality risk and underscore the traditional emphasis on the social underpinnings of disease and death.

Quality of death rates by race and Hispanic origin: a summary of current research, 1999.

OBJECTIVES: This report provides a summary of current knowledge and research on the quality and reliability of death rates by race and Hispanic origin in official mortality statistics of the United States produced by the National Center for Health Statistics (NCHS). It also provides a quantitative assessment of bias in death rates by race and Hispanic origin. It identifies areas for targeted research. METHODS: Death rates are based on information on deaths (numerators of the rates) from death certificates filed in the states and compiled into a national database by NCHS, and on population data (denominators) from the Census Bureau. Selected studies of race/Hispanic-origin misclassification and under coverage are summarized on deaths and population. Estimates are made of the separate and the joint bias on death rates by race and Hispanic origin from the two sources. Simplifying assumptions are made about the stability of the biases over time and among age groups. Original results are presented using an expanded and updated database from the National Longitudinal Mortality Study. RESULTS: While biases in the numerator and denominator tend to offset each other somewhat, death rates for all groups show net effects of race misclassification and under coverage. For the white population and the black population, published death rates are overstated in official publications by an estimated 1.0 percent and 5.0 percent, respectively, resulting principally from undercounts of these population groups in the census. Death rates for the other minority groups are understated in official publications approximately as follows: American Indians, 21 percent; Asian or Pacific Islanders, 11 percent; and Hispanics, 2 percent. These estimates do not take into account differential misreporting of age among the race/ethnic groups.

Racial disparities in CHD mortality from 1968-1992 in the state economic areas surrounding the ARIC study communities. Atherosclerosis Risk in Communities.

PURPOSE: This study examined racial variations in CHD (coronary heart disease) mortality rates (1968-1992) of residents aged 35-84 in the state economic areas (SEAs) surrounding the ARIC (Atherosclerosis Risk in Communities) study. The quarter century of CHD mortality rates are discussed in relation to racial and gender differences in baseline risk factors measured in the ARIC cohort and to the incidence of hospitalized myocardial infarction and case fatality rates obtained from the community surveillance component of the ARIC study between 1987 and 1994, inclusive. METHODS: Five-year average annual, gender- and age-specific CHD mortality rates were compared across race groups, based on National Vital Statistics data for state economic areas. RESULTS: Five-year average annual CHD mortality declined 2.6% for white men and women and 1.6% and 2.2% for black men and women, respectively. The black-white mortality rate ratio increased over time for men and women. The black-white mortality age crossover (higher black than white mortality in young men, lower black than white mortality at older ages) had disappeared by the end of the observation. CHD mortality was markedly greater in black than white women at all ages and time periods. The black disadvantage in CHD mortality was increasingly greater in the ARIC SEAs than in the United States as a whole. CONCLUSIONS: Persistent and increasing racial disparities in CHD mortality occurred in the ARIC SEAs concurrently with racial differences in risk factors, the incidence of myocardial infarction, and case fatality rates.

A comparison of the relationships of education and income with mortality: the National Longitudinal Mortality Study.

A sample of over 400,000 men and women, ages 25-64, from the National Longitudinal Mortality Study (NLMS), a cohort study representative of the noninstitutionalized US population, was followed for mortality between the years of 1979 and 1989 in order to compare and contrast the functional forms of the relationships of education and income with mortality. Results from the study suggest that functional forms for both variables are nonlinear. Education is described significantly better by a trichotomy (represented by less than a high school diploma, a high school diploma or greater but no college diploma, or a college diploma or greater) than by a simple linear function for both men (p < 0.0001 for lack of fit) and women (p = 0.006 for lack of fit). For describing the association between income and mortality, a two-sloped function, where the decrease in mortality associated with a US$1000 increase in income is much greater at incomes below US$22,500 than at incomes above US$22,500, fits significantly better than a linear function for both men (p < 0.0001 for lack of fit) and women (p = 0.0005 for lack of fit). The different shapes for the two functional forms imply that differences in mortality may primarily be a function of income at the low end of the socioeconomic continuum, but primarily a function of education at the high end.

The impact of specific occupation on mortality in the U.S. National Longitudinal Mortality Study.

We compare mortality differences for specific and general categories of occupations using a national cohort of approximately 380,000 persons aged 25-64 from the U.S. National Longitudinal Mortality Study. Based on comparisons of relative risk obtained from Cox proportional-hazards model analyses, higher risk is observed in moving across the occupational spectrum from the technical, highly skilled occupations to less-skilled and generally more labor-intensive occupations. Mortality differences obtained for social status groups of specific occupations are almost completely accounted for by adjustments for income and education. Important differences are shown to exist for selected specific occupations beyond those accounted for by social status, income, and education. High-risk specific occupations include taxi drivers, cooks, longshoremen, and transportation operatives. Low-risk specific occupations include lawyers, natural scientists, teachers, farmers, and a variety of engineers.