David M. Berkson

Alcohol consumption, cardiovascular risk factors, and mortality in two Chicago epidemiologic studies.

Multivariate analysis of the association at baseline between problem drinking and cardiovascular risk factors among 1,233 white male employees of the Chicago Peoples Gas Company age 40-59 showed the 38 problem drinkers with significantly higher blood pressures and cigarette consumption and significantly lower relative weights than the others. Similar analyses among 1,899 white male employees of the Hawthorne Works of the Western Electric Company in Chicago age 40-55 showed the 117 men consuming 5 or more drinks per day with significantly higher blood pressures and cigarette use than the others. No significant differences were recorded between heavy drinkers and the others in serum cholesterol level. The gas company problem drinkers had significantly higher 15- year mortality rates from all causes, cardiovascular diseases, coronary heart disease, and sudden death. These differences could not be entirely explained by their blood pressure, smoking, and relative weight status. The Western Electric heavy drinkers had increased 10-year mortality rates both for all causes and noncardiovascular causes.

Prevalence and incidence of coronary heart disease in strata of the labor force of a Chicago industrial corporation

Abstract 1. 1. An epidemiologic analysis of coronary heart disease and other cardiovascular-renal diseases was accomplished, utilizing the accumulated medical and personnel records on the entire male labor force aged 50 to 59 years (784 men) of a Chicago utility company. 2. 2. Observed prevalence and incidence rates for coronary heart disease were 71/1,000 and 61/1,000 for 4 years, respectively. 3. 3. The over-all mortality rate from coronary heart disease was 25/1,000 for 4. 4 years. The mortality rate in those free of coronary heart disease at the onset of the study was 17/1,000 for 4 years. Of all deaths, 47 per cent occurred suddenly. 5. 4. Hypertension, obesity, diabetes mellitus, and suspected coronary heart disease were associated with increased incidence rates of definite coronary heart disease. 6. 5. Prevalence rates of hypertension and obesity were similar in sociologic subgroups of the total population under study. Sociologic stratifications were made based on nativity, residence, military experience, education, occupation, physical activity of work, indoor versus outdoor work, and type and amount of income. 7. 6. Coronary heart disease incidence rates were similar in the sociologic subgroups, with the exception that significantly lower rates were observed in the foreign-born than in the native-born. Coronary heart disease incidence rates are high in all strata of the middle-aged male population in the United States.

Relationship of education to major risk factors and death from coronary heart disease, cardiovascular diseases and all causes, Findings of three Chicago epidemiologic studies.

The relationship of education to risk factors at baseline and to long‐term mortality from coronary heart disease (CHD), cardiovascular diseases (CVD), and all causes was analyzed for three cohorts of middle‐aged employed white men in Chicago: 8047 from the Chicago Heart Association Detection Project in Industry (CHA) (entry 1967‐1973), 1250 from the Peoples Gas Company Study (PG) (entry 1958-1959) and 1730 from the Western Electric Study (WE) (entry 1957-1958). Each man was classified into one of four groups: not a high school graduate, high school graduate, some college but not a graduate, or college graduate. For all three cohorts, a graded, inverse association was observed at baseline between education and blood pressure, which was statistically significant for CHA and WE men and independent of age and relative weight. For all three cohorts, a significant, graded, inverse association was also recorded between education and cigarette use at entry. For serum cholesterol, no clear pattern was observed for the education groups in any of the three cohorts. CHA men showed a graded, inverse relationship between education and relative weight. This cohort was the only one of three showing a significant, graded inverse association between education and prevalence of ECG abnormalities at entry. For this CHA cohort, 5-year follow-up data showed a statistically significant, graded, inverse relationship between education and ageadjusted mortality rates from CHD, CVD and all causes. With adjustment for entry age, diastolic pressure, cigarettes, serum cholesterol, relative weight and ECG abnormalities, this inverse relationship remainedreduced in degree, but still statistically significant for CVD mortality. Similarly, for the pooled PG-WE cohort of 2980 with 20-21 years of follow-up, education and the three mortality end points were inversely related but not graded, with statistical significance for all three end points in the univariate analyses. The results of these studies indicate inverse relationships between education and lifestyle-related risk factors at baseline and between education and long-term risk of CHD, CVD and all-causes mortality. The inverse relationship between education and mortality is accounted for in part by the established major biomedical risk factors.

Relationship of relative weight and body mass index to 14-year mortality in the Chicago Peoples Gas Company study.

Abstract The importance of relative weight and body mass index to 14-yr mortality of 1233 white males of the Chicago Peoples Gas Company Study is analyzed by the inclusion of a quadratic term for weight in the multiple logistic function. The endpoints of death, all causes, CVR death, and CHD death are found to have a significant quadratic relationship to body mass index for the total cohort of 1233 men, while relative weight is found to have a quadratic relationship only with death, all causes. When the group is broken into men aged 40–49 and 50–59, body mass continues to show an important quadratic relationship to all three endpoints, while relative weight shows only an important quadratic relationship to death, all causes, among men aged 50–59. When the cohort is divided into smokers and nonsmokers, body mass index shows a significant quadratic relationship to all endpoints except CHD death among nonsmokers. Relative weight, on the other hand, is related quadratically only to total mortality in both groups. The weights corresponding to the lowest mortality are found to be about 25–35 per cent above the ideal published by the Metropolitan Life Insurance Company. Thus, for this cohort moderate overweight appears to be a sign of good health. Those individuals with the highest risk are those near the so-called ideal weight and those who are markedly obese, say with a relative weight above 150 or 160.

Serum cholesterol and risk of death from cancer and other causes in three Chicago epidemiological studies

Abstract Although hypercholesterolemia is established as a major risk factor for coronary heart disease, the finding in some epidemiological studies of no association between serum cholesterol and all causes mortality suggests that serum cholesterol may be inversely related to the risk of death from non-cardiovascular causes, e.g. cancer. This possibility led to the examination of this question in middle-aged white males from the Chicago Peoples Gas Company and Chicago Western Electric Company studies, and in middle-aged white males and females from the Chicago Heart Association Detection Project in Industry. In each of these studies, there was no significant association between initial serum cholesterol level and subsequent mortality from cancer, or from causes other than cancer and the cardiovascular diseases in men. There was, however, a significant inverse association with other causes of death in women. When the cancer deaths were examined by site, there was a significant inverse association between serum cholesterol and deaths from sarcoma, leukemia and Hodgkins disease in the Western Electric men and one that was nearly so in the Chicago Heart Association men. Serum cholesterol was not significantly related to lung cancer, colorectal cancer, oral cancer, pancreatic cancer, or to all other cancers combined in any of the three studies in men or in women. There was, however, the suggestion of a positive association for breast cancer in women. Thus, the results of these three studies do not generally support the hypothesis of an inverse association between serum cholesterol and cancer in urban middle-aged white American males and females.

Uric acid: a risk factor for coronary heart disease?

The association between serum uric acid the prevalence of ECG abnormalities was analyzed for 24,997 employed men women, white black, age 18–64 years, from the Chicago Heart Association (CHA) Detection Project in Industry. In addition, the relationships between uric acid 5-year mortality from all causes, from cardiovascular diseases (CVD), from coronary heart disease (CHD) were analyzed for 7804 white men women age 45-64 years from this study 967 white men age 44–63 years from the Chicago Peoples Gas Company Study. For men, the associations between uric acid the prevalence of ECG abnormalities with mortality appear to be secondary to associations between uric acid other risk factors. For women, however, the associations could not be explained by other risk factors.

The association between urinary sodium excretion and blood pressure in children.

SUMMARYThis study explored the association between sodium excretion and blood pressure (BP). A new method was used to minimize the measurement error introduced by the large intrinsic variability of 24-hour sodium excretion. The ratio of intra- to interindividual variation was used to estimate the number of measurements needed to characterize the individual. When seven consecutive 24-hour samples were collected from 73 children, ages 11-14 years, a significant correlation between mean individual sodium excretion and BP was demonstrated. The independent relationship persisted when controlling for height, weight, pulse, age, sex and race (p = 0.045), but was eliminated by simultaneously considering mean creatinine excretion. Although the cross-sectional association described is quantitatively weak, a linear relationship between BP and sodium over the range consumed in this society could be important for prevention.

HIGH BLOOD-PRESSURE: A RISK FACTOR FOR CANCER MORTALITY ?

Univariate and multivariate analyses have been made of the relationship of systolic and diastolic blood-pressure measured at study entry to subsequent 14-year mortality among 1233 White males originally age 40-59 in 1958 from the Chicago Peoples Gas Company prospective study. With age, serum-cholesterol, and cigarettes per day controlled, both elevated systolic and electaed diastolic blood-pressure in 1958 were found to be strongly related to subsequent mortality from cancer in the men of this study. The possibility that this finding was due either to an association between antihypertensive medication in general, and cancer, or to an association was found that could explain the excess cancer mortality among those with elevated blood-pressure in 1958, either with medication in general, or with reserpine and rauwolfia in particular. These findings thus pose the question, is high blood-pressure associated with an increased risk of death due to cancer?

Multivariate analysis of the relationship of six variables to blood pressure: findings from Chicago community surveys, 1965--1971.

Abstract 1. 1. Four multivariate statistical methods—partial correlation, multiple cross classification, multiple logistic regression, and multiple linear regression—were used to study the relationship between six variables and blood pressure in over 13,000 men and women, white and black, ages 30–44 and 45–64 surveyed in two low-income Chicago communities. The analyses were carried out separately for eight age-sex-race groups. The six variables were relative weight, resting heart rate, plasma glucose 1 hr after 100 g oral load, hematocrit, serum cholesterol and age. 2. 2. The first three of these variables—relative weight, heart rate, and plasma glucose —were independently related to blood pressure with a high degree of consistency, with p values for statistical significance ≤0.001. 3. 3. Hematocrit was independently and additively related to diastolic—but not to systolic—pressure for the four age-race groups of women, but only for one of the four age-race groups of men. 4. 4. The findings with respect to serum cholesterol and blood pressure were generally negative. 5. 5. Even within the narrow age groups studied—ages 30–44 and 45–64—age was significantly related to systolic level particularly ( p values ≤0.01 or ≤0.001), independent of the five other variables. 6. 6. When multivariate regression equations and their coefficients, computed from the experience of an entire age-sex-race group, were used to calculate an expectation of elevated blood pressure for each person, and then persons were ordered from low to high in expectation, a high proportion of all persons with recorded elevations of blood pressure were in the highest decile and quintile of expected prevalence—e.g. for persons age 30–44 in the four sex-race groups, from 47–69 per cent of observed cases with diastolic pressure ≥95 mm Hg were in the highest quintile (20 per cent) of expected prevalence. The observed prevalence of elevated blood pressure was as much as 20 times as high for the highest quintile of expected prevalence as for the lowest. A similar but less effective concentration of cases of elevated blood pressure was obtained with the multiple cross classification method, by dichotomizing four of the independent variables and identifying the substratum with any two, three or all four high.

Serial Electrocardiograms After Myocardial Infarction

Excerpt Recently we have had the opportunity to assess the value of serial electrocardiograms in middle-aged men after acute myocardial infarction. This evaluation was conducted as part of a prospe...