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H Blackburn

Publications and source records attributed to H Blackburn.

At least 55 records · Page 3Linked to original sources
PubMed1995

Sex differences in early mortality after acute myocardial infarction (the Minnesota Heart Survey).

Although numerous studies indicate that women have a higher early mortality from acute myocardial infarction (AMI) than men, reasons for the difference are largely unexplained. We studied the role of sex in the prognosis of 1,600 patients with AMI aged 30 to 74 years in the population-based Minnesota Heart Survey. A 50% random sample was taken of all AMI patients hospitalized in 1980 and 1985 in the Twin Cities of Minnesota (Minneapolis-St. Paul) (1,168 men, 432 women). A multiple logistic regression model was used for predicting early death (within 28 days) and included baseline characteristics: sex, age, chest pain on admission, history of previous AMI, angina pectoris, coronary artery bypass surgery or hypertension, presence of heart failure, cardiac arrhythmias requiring direct-current shock, diabetes mellitus, valvular disease, cardiomyopathy, and levels of serum enzymes and blood urea nitrogen. Age-adjusted early mortality rate was significantly higher in women than men, but only in those aged < 65 years (12.5% of women vs 6.5% of men, p < 0.01) versus those aged > or = 65 years (19.5% vs 21.6%, p > 0.05). Multivariate analysis also showed that among those < 65 years, female sex was a strong and independent predictor of early death (odds ratio 2.0, 95% confidence interval 1.2 to 3.5, p < 0.01). Rates of coronary angiography, coronary artery bypass surgery, percutaneous transluminal coronary angioplasty, and thrombolysis performed during hospital stay were higher in men, but after adjustment for age, congestive heart failure, and diabetes mellitus, a statistically significant difference persisted only in the frequency of coronary angiography (26% in men vs 17% in women, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Average intake of anti-oxidant (pro)vitamins and subsequent cancer mortality in the 16 cohorts of the Seven Countries Study.

This ecologic study aimed to investigate whether differences in population mortality from lung, stomach and colorectal cancer among the 16 cohorts of the Seven Countries Study could be explained by differences in the average intake of anti-oxidant (pro)vitamins. In the 1960s, detailed dietary information was collected in small sub-samples of the cohorts by the dietary record method. In 1987, food-equivalent composites representing the average food intake of each cohort at baseline were collected locally and analyzed in a central laboratory. The vital status of all participants was verified after 25 years of follow-up. The average intake of vitamin C was strongly inversely related to the 25-year stomach-cancer mortality (r = -0.66, p = 0.01), also after adjustment for smoking and intake of salt or nitrate. The average intake of alpha-carotene, beta-carotene, and alpha-tocopherol were not independently related to mortality from lung, stomach or colorectal cancer, nor was vitamin C related to lung and colorectal cancer.

Adult↗
PubMed1995

Flavonoid intake and long-term risk of coronary heart disease and cancer in the seven countries study.

OBJECTIVE: To determine whether flavonoid intake explains differences in mortality rates from chronic diseases between populations. DESIGN: Cross-cultural correlation study. SETTING/PARTICIPANTS: Sixteen cohorts of the Seven Countries Study in whom flavonoid intake at baseline around 1960 was estimated by flavonoid analysis of equivalent food composites that represented the average diet in the cohorts. MAIN OUTCOME MEASURES: Mortality from coronary heart disease, cancer (various sites), and all causes in the 16 cohorts after 25 years of follow-up. RESULTS: Average intake of antioxidant flavonoids was inversely associated with mortality from coronary heart disease and explained about 25% of the variance in coronary heart disease rates in the 16 cohorts. In multivariate analysis, intake of saturated fat (73%; P = 0.0001), flavonoid intake (8%, P = .01), and percentage of smokers per cohort (9%; P = .03) explained together, independent of intake of alcohol and antioxidant vitamins, 90% of the variance in coronary heart disease rates. Flavonoid intake was not independently associated with mortality from other causes. CONCLUSIONS: Average flavonoid intake may partly contribute to differences in coronary heart disease mortality across populations, but it does not seem to be an important determinant of cancer mortality.

Adult↗
PubMed1995

Dietary saturated and trans fatty acids and cholesterol and 25-year mortality from coronary heart disease: the Seven Countries Study.

BACKGROUND: In the Seven Countries Study associations between intake of individual fatty acids and dietary cholesterol were studied in relation to serum cholesterol and 25-year mortality from coronary heart disease. All analyses concern only intercohort comparisons. METHODS: In the baseline surveys carried out between 1958 and 1964, risk factors for coronary heart disease were measured among 12,763 middle-aged men constituting 16 cohorts in seven countries. In 1987 and 1988 equivalent food composites representing the average food intake of each cohort at baseline were collected locally and analyzed in a central laboratory. The vital status of all participants was verified at regular intervals during 25 years of follow-up. RESULTS: Of the individual saturated fatty acids, the average population intake of lauric and myristic acid was most strongly related to the average serum cholesterol level (r > 0.8, P < 0.001). Strong positive associations were observed between 25-year death rates from coronary heart disease and average intake of the four major saturated fatty acids, lauric, myristic, palmitic, and stearic acid (r > 0.8, P < 0.001); the trans fatty acid elaidic acid (r = 0.78, P < 0.001); and dietary cholesterol (r = 0.55, P < 0.05). CONCLUSIONS: Interpreted in the light of experimental and clinical studies, the results of these cross-cultural analyses suggest that dietary saturated and trans fatty acids and dietary cholesterol are important determinants of differences in population rates of coronary heart disease death.

Adult↗
PubMed1995

Coronary mortality and its prediction in samples of US and Italian railroad employees in 25 years within the Seven Countries Study of cardiovascular diseases.

BACKGROUND: Samples of railroad male employees aged 40-59 were examined from companies operating in the northwest quadrant of the US in the late 1950s (n = 2571), and in Rome and surroundings. Italy in the early 1960s (n = 768) in an international co-operative study on cardiovascular diseases. METHODS: A number of cardiovascular risk factors (age, blood pressure, serum cholesterol, body mass index, subscapular skinfold, physical activity, smoking habits) were measured at year 0 and year 5, while data on mortality and causes of death were collected for 25 years. RESULTS: Coronary heart disease (CHD) death rates were always higher in the US than in Italy; after 25 years the excess was 51%. Cox proportional hazards models with CHD deaths as endpoint and seven CHD risk factors as covariates showed only the coefficients for age and smoking habits statistically different between the two cohorts. Changes in systolic blood pressure during the first 5-year follow-up were additional predictors of 5- to 25-year CHD mortality in both groups. Cholesterol plus age (greater in the US), subscapular skinfold (greater in the US) and body mass index (greater in Italy) 'explained' 67% of the observed differences in 25-year CHD mortality in the two cohorts. CONCLUSIONS: A large proportion of differential CHD mortality can be attributed to some traditional risk factors.

Adult↗
PubMed1995

Improved survival of stroke patients during the 1980s. The Minnesota Stroke Survey.

BACKGROUND AND PURPOSE: The underlying reasons for the decline in stroke mortality in the United States are not well understood and have been the subject of ongoing debate. This study was undertaken to determine whether survival of hospitalized stroke patients has changed during the 1980s, thereby contributing to the decline in stroke mortality during that period. METHODS: For the years 1980, 1985, and 1990, we obtained listings of discharge diagnoses from hospitals in the Minneapolis-St Paul metropolitan area and identified all hospitalizations with a discharge diagnosis code of acute cerebrovascular disease according to the International Classification of Diseases, 9th Revision. A 50% random sample of men and women aged 30 to 74 years was selected in each survey for detailed medical record abstraction. Standardized sets of criteria for stroke were then used to validate acute stroke events throughout the 1980s. Each of the three period cohorts of hospitalized stroke patients (1980, 1985, and 1990) was followed for at least 2 years for all-cause mortality end point. RESULTS: A total of 1853 patients met minimal criteria for acute stroke: 564 patients in 1980, 598 patients in 1985, and 691 patients in 1990. Controlling for age, the odds of death within 2 years after stroke were approximately 40% lower in 1990 than in 1980. The relative odds of 2-year death in 1990 (versus 1980) were 0.65 (95% confidence interval, 0.47 to 0.89) and 0.60 (95% confidence interval, 0.42 to 0.85) for men and women, respectively. The improved survival was evident in the short term (28 days) as well as for stroke patients who survived that period. Analysis according to stroke subtype revealed that improved survival of ischemic stroke and specifically of stroke with no apparent cardioembolic source largely accounted for the overall trend. The prognosis of stroke patients who were admitted in a comatose state has not changed during that decade. CONCLUSIONS: Despite the absence of any clear major advances in acute stroke therapy, survival of stroke patients substantially improved during the 1980s. The underlying reasons for this unexpected yet remarkable trend remain uncertain but may include improved supportive and rehabilitative care of stroke victims as well as a change in the natural history of the disease.

Adult↗
PubMed1995

The seven countries study in Japan. Twenty-five-year experience in cardiovascular and all-causes deaths.

Within the Seven Countries Study two Japanese cohorts of men aged 40-59 were enrolled, one from the farming village of Tanushimaru (n = 508) and the other from the fishing village of Ushibuka (n = 502), both located in Kyushu. Cardiovascular risk factors were measured at entry and 10 years later in the survivors. The 25-year death rate for all causes was 30% higher in Ushibuka than in Tanushimaru (p < 0.001) and higher also from specific causes except for violence. Baseline differences in the levels of age, blood pressure, serum cholesterol, smoking habits, body mass index and heart rate explained only 19% of the difference in all-cause mortality between the two towns. Multivariate models from data of the pooled cohorts showed that age was a significant predictor of coronary heart disease, stroke, cancer, all other causes and all-cause mortality. Cigarette smoking predicted coronary heart disease, cancer and all-cause mortality. Systolic blood pressure predicted coronary heart disease, stroke and all-cause mortality. Serum cholesterol, body mass index and heart rate predicted none of these five causes of death. Changes in systolic blood pressure during the first 10 years of follow-up were directly related to deaths between 10 and 25 years of follow-up, significantly improving the predictive power of the multivariate model. Changes in the other risk factors did not contribute, however, to improved prediction.

Adult↗
PubMed1995

Evaluation of weight reduction in a community intervention for cardiovascular disease risk: changes in body mass index in the Minnesota Heart Health Program.

This paper describes the effectiveness of the Minnesota Heart Health Program (MHHP) in modifying mean body mass index (BMI) in whole communities. The MHHP is a 13-year research and demonstration project designed to reduce cardiovascular risk. One member of each of three pairs of matched communities received 7 years of community intervention activities that included risk factor screening, mass media education, adult education classes, worksite interventions, home correspondence programs, school-based programs, restaurant programs, and point-of-purchase education in supermarkets. Weight gain prevention was emphasized for all adults and weight loss was encouraged among those who were obese or who had elevated risk factors known to be responsive to weight loss (e.g., high blood pressure). A strong upward secular trend in weight was noted in all MHHP communities over time. Intervention effects were evaluated conservatively with community as the unit of analysis. This analysis showed no overall effect of the MHHP intervention program on mean BMI. However, a positive intervention effect was noted early in the intervention among those with elevated cholesterol or a history of obesity-related disease. Possible reasons for this relatively weak community effect are discussed, including secular forces overwhelming intervention effects, an intervention effort not sufficiently focused on obesity, ceiling effects for weight concern in a population that was highly aware of the issue at baseline, and inherent limitations in educational approaches for this recalcitrant public health problem.

Adult↗
PubMed1994

Estimated contribution of coronary artery bypass graft surgery to the decline in coronary heart disease mortality: the Minnesota Heart Survey.

OBJECTIVES: This study assessed the possible contribution of coronary artery bypass graft surgery to the decline in coronary heart disease mortality in the Minneapolis-St. Paul metropolitan area population between 1970 and 1984. BACKGROUND: Coronary artery bypass graft surgery is a major contemporary therapeutic approach for coronary heart disease. Its use has increased over the past two decades because it provides relief of symptoms and, in certain circumstances, prolongs life. During the period that age-adjusted coronary heart disease mortality has decreased, the use of coronary artery bypass graft surgery has increased dramatically, suggesting a relation. METHODS: All 30- to 74-year old Minneapolis-St. Paul area residents undergoing coronary artery bypass graft surgery between 1970 and 1984 (9,548 patients) were registered; their medical records were abstracted; and their survival was ascertained. These data were used in a medical survival probability model using a multivariate analytical approach developed from registries of patients treated medically. The model assumed that coronary artery bypass graft surgery was not available. Two annual mortality rates were compared: the observed Minneapolis-St. Paul annual coronary heart disease mortality rate and the modeled annual coronary heart disease mortality rate. The difference between these rates was the estimated contribution of coronary artery bypass graft surgery to the decline in coronary heart disease mortality rates. RESULTS: Between 1970 and 1984, the estimated surgical contribution increased from 0.2% (increased mortality) to +6.6% of the annual decrease in Minneapolis-St. Paul coronary heart disease mortality. CONCLUSIONS: Between 1970 and 1984, the contribution of coronary artery bypass graft surgery to the decline in coronary heart disease mortality, although small, gradually increased. This change appeared to be related to an increased frequency of coronary artery bypass graft surgery, improved operative mortality and changes in the clinical mix of surgical patients.

Adult↗
PubMed1994

Trends in coded causes of death following definite myocardial infarction and the role of competing risks: the Minnesota Heart Survey (MHS).

We investigated possible differences over time in underlying causes of death among validated definite myocardial infarction cases who were discharged following an index hospitalization in 1970, 1980, and 1985 in the Twin Cities, MN. No changes were observed in underlying causes of death assigned to patients who died prior to discharge in the 3 years. Among in-hospital survivors of definite MI, however, age-adjusted rates of death from non-cardiovascular causes more than doubled between 1970 and 1985 (P < 0.01). More specifically, mortality rates for diabetes mellitus increased significantly from 1970 to 1985 (P < 0.05), while those for neoplasms and diseases of the respiratory system increased non-significantly. Whether these data are the result of artifactual changes in cause of death assignment or real changes in disease severity and comorbidity, these trends in long-term death following acute MI may have had a modest impact on reported community-wide coronary heart disease mortality rates.

Adult↗
PubMed1993

Inter-cohort differences in coronary heart disease mortality in the 25-year follow-up of the seven countries study.

Sixteen cohorts of men aged 40-59 years at entry were examined with the measurement of some risk factors and then followed-up for mortality and causes of death for 25 years. These cohorts were located in the USA (1 cohort), Finland (2), the Netherlands (1), Italy (3), the former Yugoslavia (5), Greece (2), and Japan (2), and included a total of 12,763 subjects. Large differences in age-adjusted coronary heart disease (CHD) death rates were found, with extremes of 45 per 1000 in 25 years in Tanushimaru, Japan, to 288 per 1000 in 25 years in East Finland. In general, higher rates were found in the US and Northern European cohorts as compared to the Southern European and Japanese cohorts. However, during the last 10 years of follow-up large increases of CHD death rates were found in some Yugoslavian areas. Out of 5 measured entry characteristics treated as age-adjusted levels (serum cholesterol, systolic blood pressure, cigarette smoking, body mass index and physical activity at work), only serum cholesterol was significant in explaining cohort differences in CHD death rates. Over 50% of the variance in CHD death rates in 25 years was accounted for by the difference in mean serum cholesterol. This association tended to decline with increasing length of follow-up, but this was due to the great changes in mean serum cholesterol in the two Yugoslavian cohorts of Velika Krsna and Zrenjanin. When these two cohorts were excluded the association increased with time. Changes in mean serum cholesterol between year 0 and 10 helped in explaining differences in CHD death rates from year 10 onward. It can be concluded that this study suggests that mean serum cholesterol is the major risk factor in explaining cross-cultural differences in CHD.

Adult↗
PubMed1993

Sex differences in coronary heart disease mortality trends: the Minnesota Heart Survey, 1970-1988.

Recent U.S. national statistics indicate a slowing of the rate of decline in coronary heart disease (CHD) deaths among women. To examine recent sex-specific rates of mortality decline in the Minnesota Heart Survey, we computed the average annual percentage change in age-adjusted CHD death rate for the periods 1970-1978 and 1979-1988. We fit a log-linear regression model to the yearly CHD death rates, with separate sex-specific slopes estimated simultaneously for the two calendar periods. The average annual percentage decline in age-adjusted CHD death rate among men was slightly greater in the period 1979-1988 [4.8%; 95% confidence interval (CI) = 5.2-4.3] than in the period 1970-1978 (3.9%; 95% CI = 4.6-3.1). In contrast, among women, the rate of decline was less in the period 1979-1988 (3.6%; 95% CI = 4.8-2.3) than in 1970-1978 (4.8%; 95% CI = 5.6-4.0). We found a slowing of the rate of decline in out-of-hospital CHD deaths in both men and women. We observed a large increase in the rate of decline in the CHD death rate in hospital among men in the period 1979-1988 (8.3%; 95% CI = 9.3-7.2), compared with the period 1970-1978 (2.4%; 95% CI = 3.2-1.7). This increase did not occur among women (4.1%; 95% CI = 5.7-2.5 in 1970-1980 vs 3.8%; 95% CI = 4.9-2.7 in 1970-1978); this difference is a major factor in the steeper recent decline in overall CHD mortality among men compared with women.

Adult↗
PubMed1993

Socioeconomic status and coronary heart disease risk factor trends. The Minnesota Heart Survey.

BACKGROUND: Socioeconomic status (SES) indicators including education, income, and occupation are associated with coronary heart disease (CHD) risk factors, morbidity, and mortality. In most industrialized nations, individuals with less education, lower income, and blue collar occupations have the highest CHD rates. It is suggested by some that these differences by SES are increasing even as age-adjusted CHD mortality declines. METHODS AND RESULTS: The Minnesota Heart Survey includes measurement of CHD risk factors and behaviors in population-based samples of Minneapolis-St. Paul adults aged 25 to 74 years in 1980 to 1982 (N = 3243) and 1985 to 1987 (N = 4538). Education was significantly and inversely related to blood pressure, cigarette smoking, body mass index, and a summary risk score for both men and women. Serum cholesterol was inversely related to education in women but not in men. Education was positively associated with leisure physical activity and health knowledge. Associations with household income were less consistent in magnitude and direction. Risk characteristics improved significantly between the 1980 to 1982 and 1985 to 1987 surveys. These changes were similar across education and household income levels. CONCLUSIONS: Improvement in CHD risk factors over time unrelated to education or income suggests that population-wide factors such as improved health knowledge, availability of healthy food items, hypertension treatment, and restrictions on cigarette smoking are operating beneficially in all SES groups. Although the SES gradient in risk factors is not increasing, it remains substantial and indicates directions for future prevention efforts.

Adult↗
PubMed1993

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

BACKGROUND AND PURPOSE: Age-adjusted stroke mortality rates declined approximately 50% between 1970 and 1990 in both the United States and Minnesota, but the reasons for this decline are not clear. This report examines possible improvements in short- and long-term survival of hospitalized definite stroke patients in the Minneapolis-St Paul (the Twin Cities) metropolitan area during this period. METHODS: Fifty percent random samples of patients discharged with an acute stroke diagnosis from area hospitals were selected in 1970 (n = 1200), 1980 (n = 1040), and 1985 (n = 896). Trained nurses abstracted pertinent clinical data from the hospital charts. By standardized clinical criteria similar to World Health Organization criteria (without computed tomography data), 376, 442, and 453 definite strokes were established for 1970, 1980, and 1985, respectively. RESULTS: Age- and sex-adjusted 28-day case fatality of definite stroke improved significantly from 1970 to 1985; the odds ratio (OR) of death within 28 days in 1985 (versus 1970) patients was 0.55 (95% confidence interval [CI], [0.39, 0.77]). Substantial improvements in 28-day mortality were observed both from 1970 to 1980 and from 1980 to 1985, although the latter change was not statistically significant. Further adjustment for predictors of early stroke mortality (such as level of consciousness) somewhat attenuated these results. Age- and sex-adjusted 5-year survival of definite stroke also improved significantly from 1970 to 1985 (OR, 0.72; 95% CI, [0.54, 0.96]), although the improvement was restricted to the 1970 to 1980 time period (OR, 0.76; 95% CI, [0.57, 1.01]). None of the survival trends differed significantly between men and women. CONCLUSIONS: There were marked improvements in survival from 1970 to 1985 among hospitalized stroke patients in the Twin Cities. These improvements occurred almost exclusively in the acute hospitalization phase. Although the advent of computed tomography and improvements in hospital record-keeping during this period prevent an unequivocal conclusion, improved medical care and decreased severity of stroke probably contributed to gains in survival.

Age Factors↗
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↗