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H Blackburn

Publications and source records attributed to H Blackburn.

At least 19 recordsLinked to original sources
PubMed1992

Trends in mortality, morbidity, and risk factor levels for stroke from 1960 through 1990. The Minnesota Heart Survey.

OBJECTIVE: The Minnesota Heart Survey is a population-based study designed to monitor and explain trends in cardiovascular mortality, morbidity, and risk factors. DESIGN: Surveillance time-trends study. METHODS: The following trends were examined among men and women aged 25 to 74 years living in Minneapolis-St Paul, Minn: (1) stroke mortality from 1960 through 1990; (2) risk factors in population-based surveys conducted in 1973 through 1974, 1980 through 1982, and 1985 through 1987; and (3) morbidity in a 50% sample of hospitalized discharges for acute-stroke in 1970, 1980, and 1985. RESULTS: Stroke mortality in Minneapolis-St Paul declined slowly from 1960 through 1972 (average fall, 2.4% per year), dropped sharply from 1972 through 1984 (average fall, 6.5% per year), but exhibited little change thereafter (average fall, 1.5% per year). The average level of cardiovascular disease risk factors fell from 1973-1974 to 1985-1987, with the exception of body mass index. In particular, hypertension diagnosis, treatment, and control levels improved substantially between 1973-1974 and 1980-1982, although there was little improvement after 1980-1982. While discharge rates for hospital-coded acute stroke declined substantially between 1970 and 1985 in both sexes, no clear trend was observed in definite stroke rates as validated using standard clinical criteria. Twenty-eight-day case fatality rates of definite stroke improved significantly from 1970 to 1985. CONCLUSIONS: The substantial decline in stroke mortality of more than 50% from 1960 through 1990 appears to have been attributable to both primary and secondary prevention. These data suggest that the long decline in stroke mortality and morbidity in Minneapolis-St Paul has plateaued, although improved detection of stroke with computed tomography prevents an unequivocal conclusion.

Adult↗
PubMed1992

Menopause and serum cholesterol: differences between blacks and whites. The Minnesota Heart Survey.

The relation between menopause and serum total and high-density-lipoprotein cholesterol was examined by the Minnesota Heart Survey in a cross-sectional, population-based study of 344 black women and 474 white women aged 35-54 years from the Twin Cities metropolitan area in 1985-1986. Analysis of covariance was used to examine differences in serum total and high-density-lipoprotein cholesterol in black women and white women by menopausal status, adjusting for the effects of age, educational level, cigarette smoking, body mass index, exercise, alcohol consumption, diabetes mellitus, sex hormone, beta blocker, and diuretic use. Among whites, adjusted serum total cholesterol was 13 mg/dl higher in postmenopausal than in premenopausal women (p less than 0.002). Black postmenopausal women had slightly higher serum total cholesterol than did their premenopausal counterparts (5.4 mg/dl). However, this was not statistically significant. An interaction term in a linear regression model confirmed a racial difference in the total cholesterol association with menopause (p less than 0.02). The higher total cholesterol levels observed in white postmenopausal women were mainly among those with natural menopause (20.7 mg/dl higher than premenopausal, p less than 0.0003) and those with a hysterectomy and at least one intact ovary (11.0 mg/dl higher, p = 0.05). Among black women, only the subgroup with a hysterectomy and a bilateral oophorectomy had a significantly higher serum total cholesterol (19.9 mg/dl higher than premenopausal, p less than 0.05). There was no significant association between high-density-lipoprotein cholesterol and any type of menopause in either black women or white women. Our findings may reflect a true physiologic difference in the relation between menopause and serum total cholesterol between American blacks and whites. The lack of a significant association between menopause and high-density-lipoprotein cholesterol in either race raises the possibility that menopause may not affect atherosclerosis risk via reduced high-density-lipoprotein cholesterol.

Adrenergic beta-Antagonists↗
PubMed1992

Trends in survival of hospitalized myocardial infarction patients between 1970 and 1985. The Minnesota Heart Survey.

BACKGROUND: The Minnesota Heart Survey is a population-based study designed to monitor and explain trends in cardiovascular mortality, morbidity, and risk factors. As part of this effort, a 50% sample of patients hospitalized for myocardial infarction (MI) in the seven-county Twin Cities (Minneapolis and St. Paul) metropolitan area was reviewed in 1970, 1980, and 1985. Those with a validated definite MI were followed for 4-year mortality. The purpose was to determine whether the improved survival observed between 1970 and 1980 was extended to the 1980-1985 period. METHODS AND RESULTS: Crude 28-day mortality in men changed from 18% in 1970 to 12% in 1980 to 13% in 1985; in women it changed from 27% in 1970 to 22% in 1980 to 18% in 1985. After adjustment for severity factors (e.g., age, previous MI, and admission heart rate and systolic blood pressure), 28-day mortality was significantly lower in 1980 than in 1970 in men (RR, 0.66; 95% CI, 0.47, 0.92) and in women (RR, 0.69; 95% CI, 0.46, 1.04), but no change occurred from from 1980 to 1985 (p greater than 0.25). After adjustment for severity indicators, 4-year survival was better in 1980 than in 1970 for men (RR, 0.67; 95% CI, 0.54, 0.83) and for women (RR, 0.72; 95% CI, 0.54, 0.98), but there was no significant change from 1980 to 1985 (p greater than 0.25). CONCLUSIONS: These results suggest that improvements in survival among hospitalized MI patients contributed to the overall decline in coronary heart disease mortality in the Twin Cities area between 1970 and 1980 but not between 1980 and 1985.

Adult↗
PubMed1992

Report of the Conference on Low Blood Cholesterol: Mortality Associations.

BACKGROUND: A National Heart, Lung, and Blood Institute (NHLBI) Conference was held October 9-10, 1990, to review and discuss existing data on U-shaped relations found between mortality rates and blood total cholesterol levels (TC) in some but not other studies. Presentations were given from 19 cohort studies from the United States, Europe, Israel, and Japan. A representative of each study presented its findings and also submitted tables of proportional hazards regression coefficients for entry TC levels in regard to death, and these were incorporated into a formal statistical overview adjusted for age, diastolic blood pressure, cigarette smoking, body mass index, and alcohol intake, as available. METHODS AND RESULTS: The U-shape for total mortality in men and the flat relation in women resulted largely from a positive relation of TC with coronary heart disease death and an inverse relation with deaths caused by some cancers (e.g., lung but not colon), respiratory disease, digestive disease, trauma, and residual deaths. Risk for combined noncardiovascular, noncancer causes of death decreased steadily across the range of TC. The conference considered possible explanations for the statistical associations found between low TC levels or active TC lowering and certain causes of death. One is that TC is lowered by some disease conditions themselves, such as wasting in chronic pulmonary disease or reduced production and secretion of cholesterol-bearing lipoproteins with liver disease. In this sort of situation, the TC:mortality association found in observational studies may be due to preexisting disease. This was addressed by excluding early deaths from the analysis, which did not change the results. The conference considered as well the biological function of cholesterol, which, if seriously deranged, might hypothetically cause a wide variety of diseases and dysfunction. The conference also considered the biological functions that might provide plausible mechanisms for the associations found. CONCLUSIONS: Definitive interpretation of the associations observed was not possible, although most participants considered it likely that many of the statistical associations of low or lowered TC level are explainable by confounding in one form or another. The conference focused on the apparent existence and nature of these associations and on the need to understand their source rather than on any pertinence of the findings for public health policy. Further research is recommended to explain the observed associations of low TC levels (and TC lowering) with certain noncardiovascular diseases. This includes studies of the time course of TC change in disease, the relation of TC to morbidity, further studies of possible epidemiological confounding, monitoring of population trends in TC and mortality, further studies of the relations in women, auditing of noncardiovascular events in trials, studies of cell membrane, genetic and molecular links to cholesterol metabolism, TC level and disease, studies of disease manifestations in specific lipid disorders, and further study of the proposed causal mechanisms linking low TC and hemorrhagic stroke.

Alcohol Drinking↗
PubMed1992

The US decline in stroke mortality: what does ecological analysis tell us?

We review a study in this issue that concludes, from analyses of ecological associations, that the use of medication to lower high blood pressure has caused at most a small decline in US stroke mortality rates. Our analysis suggests that other possible sources of the decline may be population-wide falls in levels of blood pressure, cigarette smoking, and coronary heart disease mortality, as well as improved treatment of cardiac and respiratory sequelae of stroke. Although the ecological method is powerful for answering questions about medical interventions' population-wide effects on disease, it must be used with care. Of particular concern are variables with meanings that differ between the ecological and the individual levels, the number of ecological units available for analysis, the sample size within the ecological units, and the range of independent variables used in ecological regression.

Aged↗
PubMed1992

Serum cholesterol level and mortality findings for men screened in the Multiple Risk Factor Intervention Trial. Multiple Risk Factor Intervention Trial Research Group.

BACKGROUND: With increased efforts to lower serum cholesterol levels, it is important to quantify associations between serum cholesterol level and causes of death other than coronary heart disease, for which an etiologic relationship has been established. METHODS: For an average of 12 years, 350,977 men aged 35 to 57 years who had been screened for the Multiple Risk Factor Intervention Trial were followed up following a single standardized measurement of serum cholesterol level and other coronary heart disease risk factors; 21,499 deaths were identified. RESULTS: A strong, positive, graded relationship was evident between serum cholesterol level measured at initial screening and death from coronary heart disease. This relationship persisted over the 12-year follow-up period. No association was noted between serum cholesterol level and stroke. The absence of an association overall was due to different relationships of serum cholesterol level with intracranial hemorrhage and nonhemorrhagic stroke. For the latter, a positive, graded association with serum cholesterol level was evident. For intracranial hemorrhage, cholesterol levels less than 4.14 mmol/L (less than 160 mg/dL) were associated with a twofold increase in risk. A serum cholesterol level less than 4.14 mmol/L (less than 160 mg/dL) was also associated with a significantly increased risk of death from cancer of the liver and pancreas; digestive diseases, particularly hepatic cirrhosis; suicide; and alcohol dependence syndrome. In addition, significant inverse graded associations were found between serum cholesterol level and cancers of the lung, lymphatic, and hematopoietic systems, and chronic obstructive pulmonary disease. No significant associations were found of serum cholesterol level with death from colon cancer, with accidental deaths, or with homicides. Overall, the inverse association between serum cholesterol level and most cancers weakened with increasing follow-up but did not disappear. The association between cholesterol level and death due to cancer of the lung and liver, chronic obstructive pulmonary disease, cirrhosis, and suicide weakened little over follow-up. CONCLUSIONS: The association of serum cholesterol with specific causes of death varies in direction, strength, gradation, and persistence. Further research on the determinants of low serum cholesterol level in populations and long-term follow-up of participants in clinical trials are necessary to assess whether inverse associations with noncardiovascular disease causes of death are consequences of noncardiovascular disease, whether serum cholesterol level and noncardiovascular disease are both consequences of other factors, or whether these associations are causal.

Adult↗
PubMed1991

Trends in serum cholesterol levels from 1980 to 1987. The Minnesota Heart Survey.

BACKGROUND AND METHODS: We assessed community trends in the awareness, treatment, and control of hypercholesterolemia (defined as a serum cholesterol level greater than 6.21 mmol per liter [240 mg per deciliter]) during the 1980s in the Minneapolis-St. Paul (Twin Cities) metropolitan area. Twin Cities residents 25 to 74 years old participated in independent, cross-sectional, population-based surveys of risk factors for cardiovascular disease in 1980-1982 (n = 3365) and 1985-1987 (n = 4545). RESULTS: Mean serum total cholesterol levels, as adjusted for age, decreased significantly (P less than 0.01) from 1980-1982 to 1985-1987 in men (from 5.30 mmol per liter [205 mg per deciliter] to 5.16 mmol per liter [200 mg per deciliter]) and women (from 5.19 mmol per liter [201 mg per deciliter] to 5.04 mmol per liter [195 mg per deciliter]). The prevalence of hypercholesterolemia as adjusted for age decreased significantly (P less than 0.05) in men (17.8 to 15.1 percent) and women (17.1 to 13.6 percent). The ratio of total cholesterol to high-density lipoprotein (HDL) cholesterol was unchanged during this period, because of a concurrent decline in the level of HDL cholesterol. Participants with hypercholesterolemia in the 1985-1987 survey were more likely than those in the 1980-1982 survey to be aware of their condition (32.6 vs. 25.4 percent), to be treated with lipid-lowering agents (4.3 vs. 1.9 percent), and to have their condition controlled (1.9 vs. 0.3 percent). Among those who reported treatment by a physician for hyperlipidemia, changes were observed in the type of treatment recommended. A significant increase (P less than 0.05) was noted from 1980-1982 to 1985-1987 in the percentage of men being treated for hyperlipidemia with lipid-lowering medication (5.2 vs. 11.6 percent) and with exercise programs (10.3 vs. 20.1 percent). In women being treated for hyperlipidemia, a nonsignificant increase was noted in the use of lipid-lowering medication (8.2 vs. 13.9 percent), and a significant increase (P less than 0.05) was observed in the number of exercise prescriptions (4.1 vs. 12.0 percent). CONCLUSIONS: We found a substantial decline in the prevalence of hypercholesterolemia in the Twin Cities between 1980-1982 and 1985-1987 that may be attributed to changes in lifestyle, such as diet and exercise, and to a lesser extent to more aggressive intervention with lipid-lowering drugs by physicians.

Adult↗
PubMed1991

All cause mortality and its determinants in middle aged men in Finland, The Netherlands, and Italy in a 25 year follow up.

STUDY OBJECTIVE: The aims were (1) to compare all cause mortality in population samples of different cultures; and (2) to cross predict fatal event by risk functions involving risk factors usually measured in cardiovascular epidemiology. DESIGN: The study was a 25 year prospective cohort study. The prediction of all cause mortality was made using the multiple logistic equation as a function of 12 risk factors; the prediction of months lived after entry examination was made by the multiple linear regression using the same factors. POPULATION SAMPLES: There were five cohorts of men aged 40-59 years, from Finland (two cohorts, 1677 men), from The Netherlands (one cohort, 878 men), and from Italy (two cohorts, 1712 men). SETTING: The Finnish cohorts came from geographically defined rural areas, the Dutch cohort from a small town in central Holland, and the Italian cohorts from rural villages in northern and central Italy. MEASUREMENTS AND MAIN RESULTS: All cause mortality was highest in Finland (557 per 1000), and lower in The Netherlands (477) and in Italy (475). The solutions of the multiple logistic function showed the significant and almost universal predictive role of certain factors, with rare exceptions. These were age, blood pressure, cigarette smoking, and arm circumference (the latter with a negative relationship). Similar results were obtained when solving a multiple linear regression equation predicting the number of months lived after entry examination as a function of the same factors. The prediction of fatal events in each country, using the risk functions of the others, produced limited errors, the smallest one being -2% and the largest +11%. When solving the logistic model in the pool of all the cohorts with the addition of dummy variables for the identification of nationality, it also appeared that only a small part of the mortality differences between countries is not explained by 12 available risk factors. CONCLUSIONS: A small set of risk factors seems to explain the intercohort differences of 25 year all cause mortality in population samples of three rather different cultures.

Adult↗
PubMed1991

Blood pressure changes as predictors of future mortality in the seven countries study.

Twelve cohorts of men aged 40-59 at entry, enrolled in six countries (Finland, The Netherlands, Italy, Yugoslavia, Greece and Japan), giving a total of 8,287 subjects, were examined for the measurement of cardiovascular risk factors and then followed-up for 20 years. Changes of systolic blood pressure (SBP) occurred over the first 10 years in 6,767 men and these values, computed by an integral-like procedure (Delta-SBP), were used as possible predictors of fatal events recorded in the second 10 years of follow-up. Men who had a relative increase of SBP in the first 10 years showed an excess risk of death as compared with those who had a relative decrease of SBP, after adjustment for age and entry levels of SBP. Such relative risks were greater than 1 in the cohorts pooled within each of the six countries, ranging from 1.07 to 1.79 for all causes of death and from 1.12 to 2.15 for atherosclerotic cardiovascular disease deaths (coronary, stroke and peripheral atherosclerotic disease). The Cox model was solved using the same two end-points as dependent variables and, as coviariates, six risk factors measured at entry examination (age, cigarettes smoked per day, body mass index, serum cholesterol, physical activity at work and systolic blood pressure). By adding Delta-SBP the predictive power of the models was significantly improved and the coefficients of Delta-SBP proved to be statistically significant.

Adult↗
PubMed1990

Twenty-five-year mortality from coronary heart disease and its prediction in five cohorts of middle-aged men in Finland, The Netherlands, and Italy.

Five cohorts of men ages 40-59 (Finland: 2 cohorts of 1,677 men; Netherlands: 1 cohort of 878 men; Italy: 2 cohorts of 1,712 men) were examined and evaluated for cardiovascular risk factors in 1959-1960 and subsequently followed-up for mortality over the next 25 years. Age-adjusted death rates from coronary heart disease were highest in Finland (244 per 1,000), intermediate in The Netherlands (195 per 1,000), and lowest in Italy (122 per 1,000) with a twofold range between the extremes. The Cox proportional hazards model was used for single cohorts and for the pools of national cohorts with coronary heart disease deaths as endpoints and 12 risk factors as covariates. It showed the significant and almost universal predictive value of these factors (with some rare exceptions). The most highly predictive values were age, blood pressure, total serum cholesterol, cigarette smoking, and physical activity (negative relationship). The prediction of events within each country using the risk function of the others produced errors ranging from -19% to +51%. The largest errors were those involving the Italian cohorts whose experience tended to underpredict coronary heart disease mortality elsewhere and to be overpredicted by the risk functions of the other countries. Solving a Cox model which included all the cohorts, and adding dummy variables for the identification of nationality, it appears that the relative risk, everything else being equal, is 1.49 and 1.34 for a Finnish man, compared with Italian and Dutch men, respectively.

Adult↗
PubMed1990

The effect of the number of electrocardiograms analyzed on cardiovascular disease surveillance: the Minnesota Heart Survey (MHS).

One method used to control costs in community cardiovascular disease surveillance is to limit the number of electrocardiograms (ECGs) used to validate acute myocardial infarction (AMI). The Minnesota Heart Survey investigated the impact of decreasing the maximum number of ECGs analyzed on classification of ECG pattern and final AMI diagnosis (definite, probable, none). A 50% sample of all 1980 acute CHD hospital discharge records (ICD-9 code 410 or 411) from 30 of 31 Twin Cities hospitals were abstracted. Comparing results using all available ECGs in the record (maximum of 12) with those obtained using up to 4 ECGs showed little differences in the ECG classification or final AMI diagnosis.

Electrocardiography↗
PubMed1990

Twenty-year stroke mortality and prediction in twelve cohorts of the Seven Countries Study.

Twelve cohorts of men aged 40-59 for a total of 8287 individuals in six countries (Finland, the Netherlands, Italy, Yugoslavia, Greece and Japan) were examined in the late 1950s or early 1960s for the measurement of some risk factors and then followed up for mortality and causes of death through 20 years. Large differences in 20-year death rates from stroke were recorded among cohorts, with the highest levels in the pool of the Yugoslavia (67 per 1000) and Japanese cohorts (62 per 1000) and the lowest in the Dutch cohort (22 per 1000). The simple linear correlation (among cohorts) of stroke mortality on mean levels at entry of some factors showed inverse significant coefficients for systolic (-0.63) diastolic (-0.51) and mean blood pressure (-0.72), and for serum cholesterol (-0.72), whereas no significant coefficients were found for mean body mass index, mean cigarette consumption and mean physical activity. The Cox model solved for six national pools of cohorts showed that only age and mean blood pressure carry significant positive coefficients, whereas all the other available factors (cigarette consumption, serum cholesterol, body mass index, physical activity) did not approach significant levels except the negative coefficients of smoking habits in Greece.

Adult↗
PubMed1990

Continued decline in cardiovascular disease risk factors: results of the Minnesota Heart Survey, 1980-1982 and 1985-1987.

Systematic, simultaneous surveillance of cardiovascular disease risk factors, morbidity, and mortality is ongoing in the Minnesota Heart Survey. Risk factors for cardiovascular disease were measured in population-based surveys of Twin Cities metropolitan area residents aged 25-74 years in 1980-1982 and 1985-1987. During this period, age-adjusted, average systolic blood pressure declined nonsignificantly in men and significantly in women, and average, age-adjusted diastolic blood pressure declined 1.1 mmHg in men and 0.9 mmHg in women. Between 1980-1982 and 1985-1987, serum total cholesterol declined significantly, 5.2 and 5.8 mg/dl in men and women, respectively. Serum high density lipoprotein cholesterol decreased 1.6 mg/dl in men and 0.9 mg/dl in women. The prevalence of cigarette smoking declined by 14% in men and 18% in women. In contrast, the average body mass index increased 0.6 kg/m2 in men and 1.2 kg/m2 in women. Systematic hospital and death certificate surveillance found that mortality rates for coronary heart disease in the Twin Cities metropolitan area declined 20.1% in men and 12.9% in women from 1981 to 1986. Despite difficulties in interpretation of ecologic studies, it appears likely that improvements in population risk factor levels played a role in the decline in disease rates and could influence future mortality trends in this population.

Adult↗