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Biomedical subjects

D R Jacobs

Publications and source records attributed to D R Jacobs.

At least 127 records · Page 7Linked to original sources
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↗
PubMed1994

Estimating the effect of regression toward the mean under stochastic censoring.

This investigation estimated regression toward the mean in the evaluation of a blood cholesterol educational program in which the probability of return for a follow-up measure was positively related to the initial measure--a situation the authors term "stochastic censoring." The situation in which selection is by a fixed cutpoint is well known. The authors estimate the extent of regression toward the mean when selection is probabilistically related to an initially higher blood cholesterol level. A Monte Carlo method is proposed, conditional on the observed data, for estimating the regression toward the mean and its precision. In 106 simulations, regression toward the mean was estimated to be 0.012 mmol/liter (standard deviation (SD), 0.032 mmol/liter). Similar estimates were obtained using Empirical Bayes shrinkage estimates of baseline cholesterol (regression toward the mean = 0.0106 mmol/liter) and numeric integration (0.0109 mmol/liter). The observed reduction in blood cholesterol was 0.271 mmol/liter (SD, 0.061 mmol/liter); after correction for regression toward the mean, the estimate of the true educational effect was 0.259 mmol/liter (SD, 0.069 mmol/liter). Functions are presented that will enable investigators to predict regression toward the mean and its standard deviation under the conditions that errors are gaussian and stochastic censoring can be approximated by a logistic model.

Cholesterol↗
PubMed1994

Assessing intervention effects in the Minnesota Heart Health Program.

The Minnesota Heart Health Program is a 13-year research and demonstration project to reduce morbidity and mortality from coronary heart disease in whole communities in the upper Midwest. Six communities were selected for the study: three intervention and three comparison sites, matched to increase baseline comparability. After 2-4 years of baseline observations, a 5- to 6-year program of intensive intervention was introduced in the three intervention communities. Periodic cross-sectional and cohort surveys provided data on risk factors and related behaviors. Regression adjustments within and between communities reduced the confounding influences of important covariates and the variance inflation associated with the nesting of individuals within communities and surveys. Post hoc stratification allowed exploration of the main and strata-specific effects of the intervention program. Finally, the intervention effect was modeled as a departure from the trend line fit to the nonintervention city-year means. Together, these procedures explicitly acknowledged the component of variance associated with communities, and so avoided a major source of bias created in the usual analysis when that variation is ignored. They also increased the interpretability of the analyses and reduced the mean square errors used to assess the treatment effects.

Cohort Studies↗
PubMed1994

Comprehensive evaluation of the Minnesota Leisure Time Physical Activity Questionnaire.

The accuracy of the Minnesota Leisure Time Physical Activity (LTPA) Questionnaire (a 1-year survey of non-occupational activity used in MRFIT) was studied in 78 men and women, age 20-59 years, by comparing survey results to the following measures obtained over a year's duration: six 48-hour physical activity records; fourteen 48-hour Caltrac accelerometer readings (Caltrac); 14 administrations of a 4-week version of the LTPA Questionnaire (FWH); 3 VO2peak determinations and percent body fat (% BF). The LTPA Questionnaire demonstrated: weak to moderate associations with % BF (r = -0.24) and with VO2peak (r = 0.47); a weak association with Caltrac readings expressed as MET.minutes.day-1 (r = 0.23); strong associations with corresponding activities reported on the FWH; and moderate associations with total and heavy activities reported in the physical activity record, but no associations with moderate and light activities. Furthermore, several types of LTPA were found to be either under-represented or not currently included in the Minnesota LTPA Questionnaire. It is concluded that although validation results were found to be quite good, several possible refinements were identified, which should improve the accuracy of the Minnesota LTPA Questionnaire in assessing habitual physical activity.

Adipose Tissue↗
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↗
PubMed1994

A comparison of two methods to ascertain dietary intake: the CARDIA Study.

Data on dietary intake were collected in the Coronary Artery Risk Development in Young Adults (CARDIA) Study at the baseline examination in 1985-86 and again at the second examination 2 years later. At baseline, a diet history questionnaire developed for the CARDIA study was used; at the second exam the NCI (Block) food frequency questionnaire was used. The purpose of the present report is to compare the estimated nutrient intakes obtained with the two instruments; to compare correlations of nutrient intakes obtained at the two exams with those observed for other lifestyle and physiological variables also measured 2 years apart; and to assess ability to test hypotheses relating 2-year changes in risk factors to between-exam differences in reported nutrient intakes. Mean levels of reported intake were generally greater for both blacks and whites on the CARDIA diet history than on the Block food frequency. Rank order correlations of reported nutrient intakes between the two questionnaires indicated greater consistency between instruments for whites (r's ranging between 0.35 and 0.52) than for blacks (r's ranging between 0.29 and 0.45). Correlations over time for nutrients were smaller than those observed for body size measures and lipid levels but were similar in magnitude to those for blood pressure, physical activity, and life events. At both exams, total caloric intake was positively associated with physical activity (range of r's for CARDIA were 0.07 for white women to 0.23 for black men, the range of r's for Block were 0.06 for women to 0.11 for white men). Using data from the two examinations, 2-year changes in total plasma cholesterol were significantly related to 2 year changes in Keys scores. The results of this comparison are useful in that they show similarities and differences between two instruments developed to gather dietary intake data. The study also illustrates the need to monitor young adults during a time when rapid changes occur in many lifestyle and physiologic factors.

Adult↗
PubMed1994

Concentrations of Lp(a) in black and white young adults: relations to risk factors for cardiovascular disease.

The purpose of this report is to compare the distribution of total lipoprotein(a) [Lp(a)] mass in a population-based sample of blacks and whites, and to investigate the association of Lp(a) with other cardiovascular risk factors. A cross-sectional study design was used. Black and white men and women (n = 4125), aged 23-35 from the Coronary Artery Risk Development in Young Adults Study had the following data collected: Lp(a), lipids and lipoproteins, other metabolic parameters, anthropometry, physical activity, dietary intake, cigarette use, and alcohol use. Blacks had concentrations of Lp(a) approximately three-fold higher than whites. Medians were: black men 21.5 mg/dL, black women 23.9 mg/dL, white men 6.1 mg/dL, and white women 6.4 mg/dL. Lp(a) concentrations were higher in women than in men. Lp(a) was not consistently associated with smoking, alcohol consumption, physical activity, dietary fat, or obesity. In stepwise regression analyses in both blacks and whites, Lp(a) was consistently associated with low-density lipoprotein (LDL) cholesterol, fibrinogen, and apoB; regression models explained about 7% of the variance in Lp(a). In whites, Lp(a) tended to be higher in those with a positive family history of myocardial infarction. The large differences in Lp(a) between blacks and whites, and the absence of association with many other variables are consistent with previous suggestions that Lp(a) concentration is in large part genetically determined. The association of Lp(a) with LDL and fibrinogen, two strong risk factors for cardiovascular disease (CVD), could represent part of the mechanism of the CVD risk associated with Lp(a) in other studies. Longitudinal data are needed to determine the extent to which Lp(a) will independently predict disease, especially in diverse ethnic groups.

Adult↗
PubMed1994

Parameters to aid in the design and analysis of community trials: intraclass correlations from the Minnesota Heart Health Program.

Community trials involve the assignment of intact social groups to study conditions and are becoming increasingly common in epidemiologic research. In both the design and analysis of these studies, whether cross-sectional or cohort, allowance must be made for the dependence of elements within intact groups if variances are to be properly estimated. In the design phase, the statistician needs estimates of the level of dependence likely to be encountered. In the analysis phase, external estimates of the level of dependence may be useful in preventing the erosion of power associated with small numbers of intact groups assigned to each condition. We report the intraclass correlation coefficients of the city-year component of variance as estimated in the Minnesota Heart Health Program for a variety of community survey variables and illustrate their use in both design and analysis. Of 23 variables assessed, all but two showed positive estimates of city-year intraclass correlations. In these data, estimates of intraclass correlation coefficients generally were in the range 0.002-0.012.

Analysis of Variance↗
PubMed1994

A comparison of lesions in small intracerebral arteries among Japanese men in Hawaii and Japan.

BACKGROUND AND PURPOSE: This report examines the hypothesis that the higher risk of stroke among Japanese men in Japan compared with those in Hawaii is related to pathology in small intracerebral arteries by comparing the prevalence of such lesions in autopsied participants from two cohorts of Japanese men in Japan and Hawaii. METHODS: Existing histological sections from the left basal ganglia from 232 men from Japan and 175 men of Japanese ancestry in Hawaii were examined for selected abnormalities in arteries between 100 and 300 microns in diameter by three pathologists. The presence of lacunar infarcts was also noted, and information about cerebral infarcts, cerebral hemorrhages, and atherosclerosis in the circle of Willis was available for the Hawaii group. RESULTS: Lacunar infarcts and all small intracerebral artery lesions except medial fibrosis were more common at every age in Japan than in Hawaii. By cause of death, all lesions were three or more times more prevalent among men who died of stroke than of noncardiovascular causes in both areas. In the Hawaii group, the small intracerebral artery lesions were significantly associated with autopsy evidence of cerebral and lacunar infarcts, and with atherosclerosis in the large arteries of the circle of Willis. Among a large number of risk factors measured at the baseline examination in Hawaii, only high blood pressure and reported usual Asian diet were significantly associated with one or more measures of small intracerebral artery lesions. CONCLUSIONS: An overview of the accumulated data indicated that small intracerebral artery pathology plays an important role in the high risk of stroke in Japanese men in Japan compared with those in Hawaii. These studies support the idea that hypertension is a necessary factor in the causal pathway, but also indicate that some other factors are involved. Some aspect of an Asian diet continues to be of importance for future research.

Age Factors↗
PubMed1994

Community education for cardiovascular disease prevention: risk factor changes in the Minnesota Heart Health Program.

OBJECTIVES: The Minnesota Heart Health Program is a 13-year research and demonstration project to reduce morbidity and mortality from coronary heart disease in whole communities. METHODS: Three pairs of communities were matched on size and type; each pair had one education site and one comparison site. After baseline surveys, a 5- to 6-year program of mass media, community organization, and direct education for risk reduction was begun in the education communities, whereas surveys continued in all sites. RESULTS: Many intervention components proved effective in targeted groups. However, against a background of strong secular trends of increasing health promotion and declining risk factors, the overall program effects were modest in size and duration and generally within chance levels. CONCLUSIONS: These findings suggest that even such an intense program may not be able to generate enough additional exposure to risk reduction messages and activities in a large enough fraction of the population to accelerate the remarkably favorable secular trends in health promotion activities and in most coronary heart disease risk factors present in the study communities.

Adult↗
PubMed1994

The relationship between cholesterol and stroke.

Epidemiologic studies generally show no relationship or a weak relationship between total stroke and total blood cholesterol level. Several Japanese epidemiologic studies of hemorrhagic stroke indicate an increased risk at lower levels of blood cholesterol. However, these studies, which do not include many people with high blood cholesterol levels, do not show an increase in stroke rate at high blood cholesterol levels. The Japanese findings for hemorrhagic stroke were replicated by the Honolulu Heart Study in migrants from Japan, and in the MRFIT Screening Study. These studies also show an increase in nonhemorrhagic stroke at the highest, but not at intermediate, levels of blood cholesterol. An extensive pathologic study of the relationship of blood cholesterol to hemorrhagic and nonhemorrhagic stroke was carried out by Dr. Konishi of Osaka. The pathology was strikingly different in the two conditions, one being atherosclerotic in the larger arteries (5 mm diameter), the other arteriolosclerotic in the intracerebral arterioles (200 microns in diameter). The relationship between blood cholesterol and arterial lesions is inverse for arteriolosclerosis and positive for atherosclerosis. It is concluded that blood cholesterol influences the development of stroke above and beyond the influence of blood pressure. Furthermore, its influence is opposite for hemorrhagic and nonhemorrhagic stroke. The relationship between blood cholesterol and atherosclerotic stroke does not appear to be as strong as it is between blood cholesterol and coronary heart disease.

Aged↗
PubMed1993

Plasma triglyceride level and mortality from coronary heart disease.

BACKGROUND: Whether the plasma triglyceride level is a risk factor for coronary heart disease has been controversial, and evaluation of the triglyceride level as a risk factor is fraught with methodologic difficulties. METHODS: We studied the association between plasma triglyceride levels and the 12-year incidence of death from coronary heart disease in 10 North American populations participating in the Lipid Research Clinics Follow-up Study, while adjusting for the potential confounding effects of other risk factors for cardiovascular disease, including the level of high-density lipoprotein (HDL) cholesterol. All analyses were sex-specific, and separate analyses were performed in high and low strata of HDL cholesterol, low-density lipoprotein (LDL) cholesterol, fasting plasma glucose, and age. RESULTS: The rates of coronary death in both men and women increased with the triglyceride level. In Cox proportional-hazards models adjusted for age, in which the natural log of the triglyceride levels was used to give a normal distribution, the relative risk per natural-log unit of triglyceride (e.g., a triglyceride level of 150 mg per deciliter vs. a level of 55 mg per deciliter) was 1.54 (95 percent confidence interval, 1.19 to 1.98; P < 0.001) in men and 1.88 (95 percent confidence interval, 1.19 to 2.98; P < 0.007) in women. After an adjustment for potential covariates, however, these relative risks were not statistically significant. Analyses based on lipoprotein cholesterol levels revealed a positive association between the triglyceride level and coronary mortality in the lower stratum of both HDL and LDL cholesterol, but not in the higher stratum. Conversely, the HDL cholesterol level was unrelated to coronary mortality in the lower stratum of LDL cholesterol, but was strongly inversely associated with coronary death in the higher stratum of LDL cholesterol. The relative risk of coronary death associated with triglyceride level was higher at younger ages. The associations between the triglyceride level and coronary mortality in the lower HDL cholesterol, LDL cholesterol, and age strata were small and were further reduced by an adjustment for the fasting plasma glucose level. CONCLUSIONS: Overall, the plasma triglyceride level showed no independent association with coronary mortality. However, in subgroups of subjects with lower HDL and LDL cholesterol levels and in younger subjects, defined a priori, an association between the triglyceride level and coronary mortality was observed, although this association was small and was not statistically significant after an adjustment for the plasma glucose level.

Adult↗
PubMed1993

[Alcohol education among junior high school students. Results from a WHO educational program].

A school-based social influences approach to alcohol education was tested among Norwegian 8th grade lower secondary school students. The goal of the programme was to delay onset and minimize involvement in use of alcohol among the participants. 15 schools were randomly assigned to peer-led education, teacher-led education or a control condition. The programme focused on the social and environmental influences to drink alcohol, and skills to resist those influences. It consisted of five lessons over two months. Baseline and post-test data measured alcohol-use, knowledge, attitudes, skills, friends' drinking, and intentions to drink alcohol in the future. Data were collected immediately prior to and following the educational programme. The data indicate that peer-led education appears to be efficacious in reducing alcohol use and intention to use alcohol. There was no intervention effect of the peer-led programme for knowledge, attitudes or skills. There was no intervention effect for the teacher-led education.

Adolescent↗
PubMed1993

Accuracy of the College Alumnus Physical Activity Questionnaire.

The validity and reproducibility of the Physical Activity Index from the College Alumnus Questionnaire (PAI-CAQ) were determined in 78 men and women (21-59 yr) with a broad range of physical activity habits. The PAI-CAQ was computed as the sum of energy expended in stair climbing, walking, and sports and recreational physical activity recalled from the past week. Data were validated against measures of cardiorespiratory fitness, body fatness, motion detection, and physical activity records. All physical activity was recorded by participants for six 48-hour periods. Each day of the week, including weekends, were represented at least twice in the physical activity records. Age-adjusted correlation coefficients between like activities on the College Alumnus Questionnaire and physical activity records ranged from 0.25 to 0.65 in men and 0.28 to 0.86 in women. Correlations between the PAI-CAQ and validation criteria that reflected total and heavy-intensity physical activities were higher (r = 0.34-0.69, p < 0.05) than for lighter-intensity physical activities and motion detection expressed in MET-min.d-1 and kcal.d-1 (r < 0.35, p > 0.05). Test-retest reproducibility was higher over 1 month (r = 0.72) than over 8 and 9 months (r = 0.34 and 0.43) (p < 0.05). Energy expended in walking and stair climbing was underestimated on the College Alumnus Questionnaire, resulting in lower PAI-CAQ scores, as compared to the physical activity records.

Adult↗
PubMed1993

Physical activity in young black and white women. The CARDIA Study.

Total physical activity scores, based on level of participation in 13 types of activities for 2658 black and white women aged 18 to 30 years were examined in relation to demographic, health behavior, psychosocial, and obesity data to compare levels of physical activity and determine reasons for disparities between blacks and whites. Black women had lower scores than white women--geometric mean of 178 (95% confidence interval (CI): 167, 189) versus 318 (95% CI: 305, 332). After controlling for age and education, physical activity was associated with physical activity level before high school, life events score, John Henryism, and competitiveness in both groups. In white women only, it was associated with alcohol intake and need to excel, and negatively associated with number of children, number of cigarettes smoked, and fatness. Race remained a predictor of physical activity after controlling for each variable. Relationships between physical activity and age, education, cigarette smoking, and life events differed significantly by race. Black women had lower physical activity levels than white women, which may contribute to higher rates of obesity and coronary heart disease. Racial differences in physical activity remain largely unexplained by the factors examined.

Adult↗
PubMed1993

The worksite component of variance: design effects and the Healthy Worker Project.

Variance estimates in worksite health promotion studies depend partly on the intraclass correlation coefficient (ICC). ICC quantifies homogeneity of a variable within worksites. ICC would be zero for randomly formed worksites, but is generally positive because employees tend to share personal characteristics. The ratio comparing the variance estimated from worksite means with that estimated from individuals under simple random sampling is the design effect (DEFF). A DEFF of 1.0 indicates no excess variance due to worksite. The Healthy Worker Project (HWP) was a 32 worksite cross-sectional and longitudinal study of a weight and smoking intervention program. ICCs in cross-sectional surveys for health-related outcome variables ranged from 0.006 to 0.009, DEFFs from 2.0 to 2.6 ICCs/DEFF's in longitudinal analysis were smaller; ICCs ranged from -0.002 to 0.003, DEFFs from 0.7 to 1.5. Positive ICCs substantially increased variance estimates at a single measurement, yet variance of longitudinal analysis was less subject to worksite dependence. It is concluded the worksite component of variance is real and should not be ignored, although the worksite component of variance is small in these longitudinal analyses. This observation should be replicated before it is used in other worksite health promotion research.

Analysis of Variance↗