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Biomedical subjects

R B Shekelle

Publications and source records attributed to R B Shekelle.

At least 37 records · Page 2Linked to original sources
PubMed1989

Dietary cholesterol and ischaemic heart disease.

In a cohort of 1824 middle-aged men followed for 25 years, intake of dietary cholesterol was associated with risk of death from ischaemic heart disease, from other cardiovascular diseases combined, from all cardiovascular diseases combined, and from all causes combined. The relative hazard of death from all cardiovascular diseases combined, associated with the difference between the mean of the first and fifth quintiles of cholesterol intake (a difference of 184 mg cholesterol/1000 kcal intake) was 1.46 (95% confidence interval 1.10-1.94) after adjustment for age, intake of other dietary lipids, and other coronary risk factors (including serum cholesterol). When stratified into three groups according to serum cholesterol (less than 220 mg/dl, 220-259 mg/dl, and 260 mg/dl or above), the corresponding relative hazards were 1.58, 1.50, and 1.41, respectively. These results are further evidence for the concepts that dietary cholesterol is atherogenic in man, and that the effect is partly independent of total serum cholesterol. They reinforce the recommendation that intake of dietary cholesterol should be low in people without overt hyperlipidaemia as well as those with raised serum cholesterol.

Adult↗
PubMed1989

Serum uric acid and 11.5-year mortality of middle-aged women: findings of the Chicago Heart Association Detection Project in Industry.

The relationships of serum uric acid to mortality from all causes, the cardiovascular diseases, and cancer were evaluated in 6797 white women age 35-64 years followed for an average of 11.5 years in the Chicago Heart Association Detection Project in Industry (CHA). Serum uric acid levels at baseline were strongly and significantly associated with all causes mortality in this cohort, with control for multiple risk factors and with exclusion of hypertensives on treatment. When the analysis was performed on age-specific groups 35-44, 45-54, and 55-64 years of age, the association was observed primarily in women in the oldest age group. All cardiovascular deaths, deaths due to coronary heart disease, and all cancer deaths were also associated with serum uric acid levels in the 55-64 year old group. The relationships persisted with control for multiple risk factors and with exclusion of treated hypertensives. A site-specific analysis of cancer deaths demonstrated elevations in mean serum uric acid levels for nearly all sites. Differences in mean serum uric acid levels between decedents and survivors tended to be largest in the first 5 years of follow-up for the cardiovascular deaths, but for cancer decedents they tended to be larger for subsequent years of follow-up. As an initial report on the association of serum uric acid and cancer in women in this age group, the results of this study require confirmation. Although hormonal influences may play a role, pathophysiologic mechanisms relating serum uric acid to mortality in white women aged 55-64 are currently unknown.

Adult↗
PubMed1989

Large fluctuations in body weight during young adulthood and twenty-five-year risk of coronary death in men.

The hypothesis that large fluctuations in weight during young adulthood are associated with increased risk of coronary heart disease was investigated by comparing the 25-year mortality of three groups of middle-aged men with distinctly different patterns of self-reported weight during young adulthood: 98 men who reported large gains and large losses, 133 who reported large gains and no losses, and 178 who reported no substantial change in weight. They were selected from a cohort of 2,107 men aged 40-56 years who participated in the Western Electric Study from 1957 through 1983. The 25-year crude risk of coronary death was 26% in the "gain and loss" group, 15% in the "gain only" group, 14% in the "no change" group, and 17% in the remaining 1,550 men. After adjustment for age and major coronary risk factors, the relative risk of coronary death in the gain and loss group as compared with the no change group was 2.0 (95% confidence interval 1.2-3.5). Risk of death from cancer was highest in the gain only group, and risk of death from all causes combined was lowest in the no change group. These results support the concept that large changes in weight during young adulthood increase the risk of coronary disease and of cancer.

Adult↗
PubMed1988

Major and minor electrocardiographic abnormalities and risk of death from coronary heart disease, cardiovascular diseases and all causes in men and women.

The independent contributions of baseline major and minor electrocardiographic (ECG) abnormalities to subsequent 11.5 year risk of death from coronary heart disease, all cardiovascular diseases and all causes were explored among 9,643 white men and 7,990 white women aged 40 to 64 years without definite prior coronary heart disease in the Chicago Heart Association Detection Project in Industry. At baseline, prevalence rates of major ECG abnormalities were higher in women than in men, with age-adjusted rates of 12.9 and 9.6% (p less than 0.01), respectively. Minor ECG abnormalities were more common in men than in women (7.3 versus 4.5%, p less than 0.01). Both major and minor ECG abnormalities were associated with an increased risk of death from coronary heart disease, all cardiovascular diseases and all causes. The strength of these associations was greater in men than in women. When baseline age, diastolic pressure, serum cholesterol, cigarettes smoked per day, diabetes and use of antihypertensive medication were taken into account, major abnormalities continued to be significantly related to each cause of death in both genders with much larger adjusted absolute excess risk and relative risk for men than for women. In multivariate analyses, minor ECG abnormalities contributed independently to risk of death in men, but not clearly so in women. The results indicate the independent association between ECG abnormalities and mortality from coronary heart disease, all cardiovascular diseases and all causes, with greater relative significance in middle-aged United States men than women.

Adult↗
PubMed1988

Education, smoking and non-cardiovascular mortality: findings in three Chicago epidemiological studies.

The interrelationships among education, smoking, and non-cardiovascular (non-CVD) mortality were examined in middle-aged white males from the Chicago Peoples Gas Company Study (PG), the Chicago Western Electric Company Study (WE), and the Chicago Heart Association Detection Project in Industry (CHA). In each study, college graduates had the lowest prevalence of current smokers and the highest prevalence of former smokers. The associations between education and smoking were strongest in CHA, a study with baseline measurements 10-14 years after those of PG and WE and 3-8 years after the US Surgeon General's report on smoking and health in 1964. In PG and WE, the relative risks of non-CVD death for those who did not attend college compared to those who did were 1.50 and 1.38 (95% limits, 1.04 to 2.18 and 0.95 to 2.02). In CHA, the relative risk for those who did not graduate from college compared to those who did was 1.55 (1.17, 2.05). Differences in baseline cigarette smoking could account for only 23-29% of these increased risks. Because the associations between education and non-CVD mortality may have been confounded by changes in smoking status over the course of follow-up in these studies, non-CVD deaths were subdivided into those from causes related to smoking and causes not related to smoking. For smoking-related causes, the relative risk of death for those who did not attend/graduate from college was 1.95 (0.96, 3.95) in WE, 2.13 (1.18, 3.87) in PG, and 2.34 (1.47, 3.84) in CHA, while the relative risks for causes not related to smoking were 1.17, 1.12 and 1.16, respectively. These findings suggest that education is related inversely to non-CVD mortality primarily through smoking and smoking-related causes of death. With smoking becoming increasingly a habit of the less well-educated, these findings underscore the need for smoking prevention and cessation programmes targeted at the lower end of the socioeconomic scale.

Adult↗
PubMed1987

The role of relative weight in the positive association between age and serum cholesterol in men and women.

With advancing age from youth on, there is an increase in mean serum cholesterol level of populations in "western" industrialized countries. Since serum cholesterol is one of the established major risk factors for premature coronary heart disease, it is important to explore the degree to which this age trend is physiologic or due to modern life styles. This study used cross-sectional data for 19,730 white men and 13,872 white women from the Chicago Heart Association Detection Project in Industry to investigate one aspect of this question: does weight explain the association between age and serum cholesterol, in particular whether older age is associated with higher serum cholesterol in the absence of overweight. The relationships among age, relative weight, and serum cholesterol were examined through assessment of mean serum cholesterol levels in 25 subgroups stratified by age (18-24, 25-34, 35-44, 45-54, 55-64) and by relative weight (less than 100, 100-109, 110-119, 120-134, greater than or equal to 135). Age and serum cholesterol were positively associated with each other. In women, it was a simple, linear relationship. In men, the degree of this positive association was less in people over age 35-44 than people in younger ages. These age-cholesterol patterns were present in men and women at desirable weight. However, in men aged 18-54, the positive association between age and prevalence of marked hypercholesterolemia (serum cholesterol greater than or equal to 250) was lower in people at desirable relative weight in comparison to those at higher relative weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Intra- and interindividual variation in measurements of beta-carotene, retinol, and tocopherols in diet and plasma.

Twenty-four men were studied for 4 wk to estimate intra- and interindividual variation of retinol, beta-carotene, and tocopherols in diet and plasma. Ratios of intra- to interindividual variances ranged from 0.62 for beta-carotene in plasma to 6.02 for vitamin E in diet. Results indicate that 3-9 independent measurements may be required to distinguish reliably even large differences (approximately 1 SD) in these micronutrients; 28-86 independent measurements may be needed for small differences (approximately 0.25 SD). If uncontrolled, large ratios of intra- to interindividual variance can constitute an important source of error in studies of micronutrients.

Adult↗
PubMed1987

Coffee consumption and mortality in the Chicago Western Electric Company Study.

The relations between coffee consumption and 19-year mortality from all causes, coronary heart disease, and non-coronary causes were assessed in 1,910 white males aged 40-56 years in 1957-1958 from the Chicago Western Electric Company Study. Mortality rates, adjusted for age, serum cholesterol, diastolic blood pressure, and smoking status, were compared for those consuming 0-1, 2-3, 4-5, and 6+ cups of coffee per day; coffee intake, measured at the first anniversary examination, included both caffeinated and decaffeinated intake. Mortality from all causes was greatest in the highest and lowest intake groups. The increased mortality in the 6+ cups per day group was due to coronary heart disease, while the increased mortality in the lowest intake group was due to noncoronary causes. The adjusted relative risk of coronary heart disease death for those drinking 6+ cups of coffee per day compared with those drinking less was 1.71 (95 per cent confidence limits 1.27, 2.30). This increased risk of coronary heart disease death was present in both smokers and nonsmokers, with adjusted relative risks of 1.62 and 2.21, respectively (95 per cent confidence limits 1.17, 2.24 and 1.06, 4.62). The increased mortality from non-coronary causes in the lowest intake group was due primarily to increased mortality from cancer and cardiovascular diseases other than coronary heart disease. The results of this study support the hypothesis that those who drink 6+ cups of coffee per day may be at an increased risk of death from coronary heart disease.

Adult↗
PubMed1987

Sex differential in the relationship of electrocardiographic ST-T abnormalities to risk of coronary death: 11.5 year follow-up findings of the Chicago Heart Association Detection Project in Industry.

The independent contributions of ST segment depression and/or T wave abnormality (ST-T abnormalities) on the baseline resting electrocardiogram to risk of 11.5 year coronary heart disease (CHD) mortality were explored among 9203 white men and 7818 white women who were 40 to 64 years old and without definite CHD at entry in the Chicago Heart Association Detection Project in Industry. At baseline, prevalence rates of ST-T abnormalities were age related for both sexes, and at every age the rate was higher in women than men (age-adjusted prevalence rates 12.3% and 8.1%, respectively). Univariate analysis showed that ST-T abnormalities were associated with significantly increased risk of death from CHD for both men and women. However, men with ST-T abnormalities had much greater age-adjusted and multiple risk factor-adjusted absolute excess risk and relative risk than women with such electrocardiographic abnormalities. When baseline age, diastolic pressure, serum cholesterol, cigarettes/day, history of diabetes, and baseline use of antihypertensive medication were included in the multivariate analysis, ST-T abnormalities remained significantly related to death from CHD in men but not women. The interaction term between sex and ST-T abnormalities was at a borderline level of statistical significance by Cox regression analysis. In conclusion, ST-T abnormalities indicate an increased risk of subsequent death from CHD independent of major coronary risk factors for middle-aged U.S. men, but this is not clearly so for women.

Adult↗
PubMed1986

Characteristics and prognosis of incomplete right bundle branch block: an epidemiologic study.

A cohort of 1,960 white men aged 40 to 56 years without initial apparent heart disease and with 11 years of annual rest electrocardiograms and 20 year mortality data was followed in the Chicago Western Electric Company Study. Incomplete right bundle branch block was found in 134 men (6.8%) at entry. During follow-up, 222 men developed such block, an incidence rate of 13.6%. Left axis deviation of -30 degrees or less was more frequent in men with than in those without incomplete block at entry (8.2 versus 2.4%). Men with left axis deviation also had a higher incidence of incomplete right bundle branch block. Similarly, men developing incomplete block had a significantly greater risk of developing left axis deviation. The associations between incomplete block and left axis deviation were unrelated to age and body weight. Men with incomplete block had a significantly greater likelihood of developing complete right bundle branch block. The 11 year incidence rate of complete block was 5.1% for men with baseline incomplete block and 0.7% for those without. Complete block developed in 2 of 220 incident cases of incomplete block but in none of the 440 control men matched by age and duration of follow-up. Although incomplete right bundle branch block was not related to an increased risk of death in 20 years from coronary heart disease and cardiovascular diseases, the study data suggest that such block is frequently a manifestation of primary abnormality of the cardiac conduction system in middle-aged men.

Actuarial Analysis↗
PubMed1986

Relationship of clinical diabetes and asymptomatic hyperglycemia to risk of coronary heart disease mortality in men and women.

This epidemiologic study explored the sex differential in risk of death from coronary heart disease in persons with or without clinically diagnosed diabetes or asymptomatic hyperglycemia. Use was made of 9-year follow-up data from the Chicago Heart Association Detection Project in Industry for 11,220 white men and 8,030 white women aged 35-64 years at entry to the Project (November 1967-January 1973). Both clinically diagnosed diabetes and asymptomatic hyperglycemia were associated with an increased risk of death from coronary heart disease. The extent of this association was greater in women than in men in regard to relative risk. However, absolute excess risk for both diabetics and those with asymptomatic hyperglycemia was larger for men than for women. Clinical diabetes appeared to be an independent risk factor for coronary heart disease in both men and women based on multivariate Cox regression analyses. On the other hand, for men, no significant independent effect of asymptomatic hyperglycemia was apparent. Women with asymptomatic hyperglycemia had significantly higher coronary heart disease death rates than normoglycemic women, with adjustment for major coronary heart disease risk factors; in multivariate analyses, the relationship of asymptomatic hyperglycemia to risk of coronary heart disease was of borderline significance (p = 0.054). This study indicates the independent associations of diabetes and possibly asymptomatic hyperglycemia with coronary heart disease mortality, with greater relative significance in women than in men.

Adult↗
PubMed1986

The role of weight in the positive association between age and blood pressure.

This study used cross-sectional data for 19,704 white men and 13,895 white women from the Chicago Heart Association Detection Project in Industry (November 1967 to January 1973) to investigate whether weight explains the association between age and blood pressure, and in particular, whether age is associated with blood pressure and hypertension in the absence of overweight. The relations among age, relative weight, and blood pressure were examined through assessment of mean blood pressure levels and prevalence of hypertension in 25 subgroups stratified by age (18-24, 25-34, 35-44, 45-54, and 55-64 years) and by relative weight (less than 100%, 100-109%, 110-119%, 120-134%, and greater than or equal to 135%). For all five relative weight groups, for both men and women, mean diastolic blood pressure was higher at successive ages. This phenomenon was also seen for systolic blood pressure after ages 35-44 years for men, and after ages 25-34 years for women. On the other hand, the higher the relative weight was, the higher the blood pressure was. Regression analysis demonstrated that the observed relation between age and blood pressure was consistent for all five relative weight groups, including those at desirable weight. These data indicate that for US subjects, age and blood pressure are generally associated in the absence of overweight.

Adolescent↗
PubMed1985

Type A score (Jenkins Activity Survey) and risk of recurrent coronary heart disease in the aspirin myocardial infarction study.

The Jenkins Activity Survey (JAS), a questionnaire developed to assess the type A behavior pattern, was administered to 2,314 participants in the Aspirin Myocardial Infarction Study. All had a myocardial infarction (MI) before entering the study and were followed for at least 3 years. The JAS type A score was not significantly related to risk of recurrent major coronary events (definite nonfatal MI and coronary death) in the group of 244 women, the group of 2,070 men, or the subgroup of 671 men who were employed full-time in professional, technical or managerial positions. These results indicate that the JAS type A score is not useful in assessing prognosis after MI. By inference, traits measured by the JAS type A score, such as competitiveness, orientation toward achievement and preference for a rapid pace of life, appear not to be associated with increased risk of recurrent major coronary events.

Adult↗
PubMed1985

Dietary vitamin D and calcium and risk of colorectal cancer: a 19-year prospective study in men.

Mortality rates from colon cancer in the USA are highest in populations exposed to the least amounts of natural sunlight; differences in endogenous vitamin D production and calcium absorption could be responsible. To investigate this possibility, the association of dietary vitamin D and calcium with 19-year risk of colorectal cancer was examined in 1954 men who had completed detailed, 28-day dietary histories in the period 1957-59. Risk of colorectal cancer was inversely correlated with dietary vitamin D and calcium. In the quartiles of a combined index of dietary vitamin D and calcium, from lowest to highest, observed risks of colorectal cancer were 38.9, 24.5, 22.5, and 14.3/1000 population. This association remained significant after adjustment for age, daily cigarette consumption, body mass index, ethanol consumption, and percentage of calories obtained from fat.

Adult↗
PubMed1985

Need to prevent and control high-normal and high blood pressure, particularly so-called "mild" hypertension: epidemiological and clinical data.

The need to prevent and control high blood pressure (HBP), including so-called "mild" hypertension [diastolic blood pressure (DBP) 90-104 mm Hg in adults age 30+] stems from the extensive data on the increased risks due to these common blood pressure (BP) levels, including risk of catastrophic cardiovascular events (coronary, cerebrovascular, etc.), both nonfatal and fatal. Prospective population data from the national cooperative Pooling Project and the Chicago Heart Association Detection Project in Industry illustrate the extensively documented facts. They also show that only a small minority of middle-aged and older Americans have optimal low-normal BP levels, i.e., DBP less than 80 mm Hg (SBP less than 120). Thus, the problem of BP above optimal level for health over a long life span is a population-wide problem. The data also show that the great majority of excess catastrophic events attributable to elevated BP occur among people with DBP 90-104 and 80-89 mm Hg, levels very common in the population. Most people with such BP levels also have one or more other major risk factors (e.g., hypercholesterolemia, cigarette use, ECG abnormalities) and thus are at markedly increased risk, both relative and absolute. In addition to these excess risks for major illness, disability, and death, people with BP above optimal levels are more highly prone to other events, clinical and subclinical, that have adverse effects on long-term prognosis, including development of target organ damage and severe hypertension. These data lead to the following inferences about medical care and public health strategy: (a) A key task is, by safe nutritional-hygienic means, to shift the entire population distribution of BP downward, for both primary and secondary prevention of HBP. Such means include prevention and control of obesity, high sodium and alcohol intake, and sedentary habit, from early childhood on. (b) People with DBP 80-89 mm Hg need to be identified promptly, with institution of nutritional-hygienic measures to prevent development of frank hypertension and to correct other risk factors. (c) People with DBP 90-104 and higher need to be identified promptly, with institution of measures to normalize BP and control other major risk factors, by nutritional-hygienic means alone whenever possible or in combination with drug treatment for HBP when necessary to prevent organ system damage, serious illness, disability, and premature death.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1985

The MRFIT behavior pattern study. II. Type A behavior and incidence of coronary heart disease.

Behavior pattern was assessed by interview for 3,110 men at eight centers in the Multiple Risk Factor Intervention Trial (1973-1976). The Type A pattern was not significantly associated with risk of first major coronary events (coronary death and definite nonfatal myocardial infarction) after a mean follow-up of 7.1 years. Crude relative risks for Types A1-A2 versus X-B were 1.08 in usual care, 0.82 in special intervention, and 0.92 overall. Adjustment for age, blood pressure, cigarette smoking, serum cholesterol, consumption of alcohol, and educational attainment yielded relative risks of 0.99 in usual care, 0.81 in special intervention, and 0.87 overall (95% confidence interval = 0.59-1.28). The Jenkins Activity Survey Type A score, obtained for 12,772 men at all 22 centers, was also not significantly associated with risk of first major coronary events. Overall, crude risks in the lowest (Type B) through highest (Type A) quintiles of the score's distribution were 5.0%, 4.4%, 4.0%, 4.3%, and 4.1%, respectively. The proportional hazards regression coefficient, adjusted for the variables listed above, was -0.006 (95% confidence interval = -0.015-0.003). These results raise questions regarding the robustness of the Type A hypothesis in its present form. Further studies are needed to investigate these questions and to evaluate the validity of procedures used to assess behavior patterns.

Adult↗