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Biomedical subjects

R S Paffenbarger

Publications and source records attributed to R S Paffenbarger.

At least 109 records · Page 6Linked to original sources
PubMed1980

Characteristics that predict risk of breast cancer before and after the menopause.

In a case-control study of 1868 breast cancer patients and 3391 control patients we searched for characteristics that predicted risk of breast cancer diagnosed before and after menopause. Common to increased risk of this disease in both periods of womanhood were: early menarche and late menopause; delayed marriage and first childbirth; more nulliparity or reduced gravidity and parity; reduced frequency of abortions; shorter overall child-bearing interval; more advanced education, higher socioeconomic status, and more contraceptive usage; and familial tendencies toward the disease. Breast cancer patients diagnosed before menopause were leaner than controls at age 20 and at time of diagnosis, but breast cancer risk in the postmenopausal period was related to increased weight-for-height at diagnosis and greater weight-for-height at diagnosis and greater weight gain since age 20. Postmenopausal breast cancer patients had a longer interval between first and second childbirths. Frequency and duration of the gravid state, inversely related to breast cancer risk, were largely dependent on contraceptive practices rather than unexplained infertility per se. Whether the breast cancer reaches diagnosis before or after menopause, the bulk of evidence examined here supports the view that it has a common cause and is subject to modifying influences over the long period of cancer latency.

Abortion, Spontaneous↗
PubMed1979

Work activity and fatal heart attack studied by multiple logistic risk analysis.

A group of 3975 San Francisco longshoremen in cohorts classified annually by work activity (WA) was followed for fatal heart attack (FHA) over a 22-year period. In 57,632 person-years of follow-up, 410 men died from heart attack. A multi-factor logistic analysis was used to study work energy output adjusted for age, race, systolic blood pressure, smoking, body mass index, glucose intolerance and EKG status as predictors of FHA. After adjustment for these factors, men with a high WA of 7 kcal/min above basal metabolism at the beginning of a yearly follow-up period had a FHA rate about one-half the rate for men in the lowest WA category of 1 kcal/min above basal metabolism (p = 0.0003). In addition, the predictability of average WA during the four years preceding a yearly follow-up period was isolated to see if the lower risk associated with high WA derives from selective factors. After adjustment for factors described above and also for rate of change in WA used to represent selective factors, subjects with WA of 7 kcal/min still had about one-half the FHA rate observed for men at the lowest WA level (p = 0.0006). The findings from these and other phases of the analysis are consistent with the hypothesis that a substantial protective effect against FHA results from vigorous physical exertion.

Adult↗
PubMed1979

Epidemiologic characteristics of breast cancer in three menopausal stages: preliminary findings.

A preliminary analysis of data from 1,477 patients with breast cancer and 2,695 control women examined potential characteristics of high risk for breast cancer to determine whether prediction differed depending on whether the women were premenopausal, paramenopausal (intermediate), or postmenopausal. Since information was not yet available on real or presumed menopausal status, women were characterized by age: women less than 45 years as premenopausal; women from 45 through 54 years as paramenopausal; and women 55 years and older as postmenopausal. Height, weight at age 20, number of stillbirths, number of abortions, and history of cancer of any site in the subject's mother did not affect the risk of breast cancer. Generally, highest level of education, number of pregnancies, and number of live births seemed to predict risk of breast cancer. Weightbody mass index, age at menarche, and age at first pregnancy may predict breast cancer risk differently depending on the menopausal stage in which onset occurs.

Adult↗
PubMed1978

Physical activity as an index of heart attack risk in college alumni.

Risk of first heart attack was found to be related inversely to energy expenditure reported by 16,936 Harvard male alumni, aged 35-74 years, of whom 572 experienced heart attacks in 117,680 person-years of followup. Stairs climbed, blocks walked, strenuous sports played, and a composite physical activity index all opposed risk. Men with index below 2000 kilocalories per week were at 64% higher risk than classmates with higher index. Adult exercise was independent of other influences on heart attack risk, and peak exertion as strenuous sports play enhanced the effect of total energy expenditure. Notably, alumni physical activity supplanted student athleticism assessed in college 16-50 years earlier. If it is postulated that varsity athlete status implies selective cardiovascular fitness, such selection alone is insufficient to explain lower heart attack risk in later adult years. Ex-varsity athletes retained lower risk only if they maintained a high physical activity index as alumni.

Adult↗
PubMed1978

Chronic disease in former college students. XVII. Sociocultural mobility as a precursor of coronary heart disease and hypertension.

The relationship between sociocultural mobility and subsequent coronary heart disease (CHD) and hypertension (HT) was studied in a cohort of 13,728 male former Harvard University students examined in 1939-1950. All 13,728 were followed for CHD mortality, while 8852 returned self-administered mail questionnaires in 1962 or 1966 and in 1972 which queried for doctor-diagnosed myocardial infarction (MI), angina pectoris (AP) and HT. For each of 98 cases of fatal CHD, 78 cases of MI and 48 cases of AP, four controls were randomly selected. One control was selected for each of 319 HT cases. Significant negative associations between father's occupational status and risk of combined fatal CHD and MI and between geographic mobility and risk of HT were noted in univariate analysis. These associations persisted with stratification by individual confounding factors and by a multivariate confounder-summarizing score. Intergenerational mobility, as indicated by occupational status of the father, was associated with a 1.5 times increased risk of fatal CHD and MI. Intragenerational geographic mobility was associated with a slightly reduced risk of HT.

Adolescent↗
PubMed1978

Energy expenditure, cigarette smoking, and blood pressure level as related to death from specific diseases.

In a 22-year followup of 3686 San Francisco longshoremen, the roles of physical activity, cigarette smoking habit, and systolic blood pressure level were evaluated independently in relation to risk of death from a broad range of diseases. Smoking pattern and blood pressure status were established in 1951 and job activity was assessed annually during the followup period. Lower levels of energy expenditure predicted increased risk of fatal heart attack and perhaps of stroke. Heavy cigarette smoking predicted increased risk of death from heart attack, cancer, chronic obstructive respiratory disease, and pneumonia. Higher levels of systolic blood pressure were associated with death from all cardiovascular diseases, diabetes mellitus, and cirrhosis. Tacit to these findings: sedentary living takes its toll largely through heart disease and stroke; the toxicity of cigarette smoking is associated with a broader range of diseases, including heart attack, cancer, and respiratory disease; and higher level of blood pressure related to an even broader range of cardiovascular disease than either of the other characteristics studied.

Adult↗
PubMed1977

Cancer risk as related to use of oral contraceptives during fertile years.

A case-control study of 452 breast cancer patients, aged less than 50 years, and 872 age-, race-, and religion-matched control patients generated relative risk estimates of breast cancer associated with oral contraceptive practices. The relative risk of breast cancer from ever-use of oral contraceptives was 1.1, not significant. Relative risks did not differ by age, interval since first use, interval since last use, or time periods in which steroid compounds differed in composition and potency. However, the relative risks of breast cancer from current use, from 2 to 4 years of ever-use, from 6 or more years of use by women with prior benign breast disease, and from use before first childbirth were increased significantly. The findings suggest the malignant process may be quickened if transformed cells are present during oral contraceptive use. Yet, the findings neither indicate that oral contraception induces breast cancer nor do they exonerate female steroid hormones. The findings do encourage continued surveillance of steroid contraception for cancer induction or promotion. In addition to duration of oral contraceptive use and other measures of dose response, future observations should pay especial attention to use by women before first childbirth and by women with already established benign breast disease.

Adolescent↗
PubMed1977

Characteristics in youth indicative of adult-onset Hodgkin's disease.

From the college entrance health data of 50,000 male former students, the records of 45 who eventually died of Hodgkin's disease were compared with those of 180 surviving classmates with reference to certain indicator characteristics. Risk ratios of Hodgkin's disease tended to be lower for men who had experienced various common contagious diseases in childhood. This reduced incidence of clinical contagions may signify that: 1) Inadequate early challenge of immune mechanisms left subjects more susceptible to later Hodgkin's disease, whether or not it is of infectious origin; 2) heightened immune mechanisms that led to subclinical attacks of early contagious diseases promoted an autoimmune response that evolved as Hodgkin's disease; or 3) early childhood infections eliminated some subjects who otherwise would have attended college and ultimately developed adult-onset Hodgkin's disease. Also, Hodgkin's disease risk was higher for students who had reported early death of a parent, particularly from cancer. Moreover, the risk tended to be increased among collegians who were obese, heavy cigarette smokers, and coffee drinkers. None of these indicator characteristics was associated with 89 fatal lymphomas of other types that occurred in the same study population.

Adult↗
PubMed1977

Work-energy level, personal characteristics, and fatal heart attack: a birth-cohort effect.

In a 22-year followup of 3686 San Francisco longshoremen, a cohort analysis assessed job activity and six personal characteristics in relation to 395 fatal heart attacks. Four cohorts aged 35-44, 45-54, 55-64, and 65-74 in 1951 were studied annually for job shifts affecting energy output and for sudden or delayed death from heart attack by age 75. All subjects underwent multiphasic screening for heavy cigarette smoking, higher blood pressure, history of prior heart disease, obesity, abnormal glucose metabolism, and higher blood cholesterol. The first three of these characteristics added risk of fatal heart attack. The amount of risk varied in the four cohorts. Higher energy output on the job reduced risk of fatal heart attack, especially sudden death, in the two younger cohorts, where less active workers were at threefold increased risk. Lack of this effect in the two older cohorts could imply real differences in their work habits, such as being less energetic in heavy jobs or more energetic in light jobs than the younger cohorts. Or, before the study began, early deaths may have winnowed susceptibles from the two older cohorts. Combined low-energy output, heavy smoking, and higher blood pressure increased risk by as much as 20-fold. By elimination of these adverse influences, this population might have had an 88% reduction in its rate of fatal heart attack during the 22 years.

Adult↗
PubMed1975

Work activity and coronary heart mortality.

To appraise the role of physical activity in reducing coronary mortality among longshoremen, 6351 men, 35 to 74 years old upon entry, were followed for 22 years or to death or to the age of 75. Their longshoring experience was computed in terms of work-years according to categories of high, medium and low caloric output. Individual work assignments were reclassified annually to allow for effect of job transfers. The age-adjusted coronary death rate for the high-activity category was 26.9 per 10,000 work-years, and the medium and low catgories had rates of 46.3 and 49.0 which were little different from each other. This protective "threshold" effect was seen especially for the sudden-death syndrome, in which the death rate for heavy workers was 5.6, as contrasted with 19.9 for moderate and 15.7 for light workers. We conclude that repeated bursts of high energy output established a plateau of protection against coronary mortality, and that several different mechanisms may explain this finding.

Adult↗
PubMed1975

Oral contraceptives as related to cancer and benign lesions of the breast.

We conducted a case-control study to search for any relationship between use of oral contraceptives and development of breast cancer or benign breast disease. Women less than 50 years old with these diseases were matched with 2 controls by age, race, religion, and hospital. Home interviews elicited information on oral contraceptive use and other host and environmental factors. The study population comprised 1,770 women, including 452 with breast cancer and 446 with benign breast disease. The relative risk of developing cancer or benign disease was measured by matched set and summary chi-square analyses. Although the relative risk of developing breast cancer among "ever-users" of oral contraceptives was 1.1, the risk among women using oral contraceptives for 2-4 years was 1.9 (significantly increased). This risk estimate reached 2.5 for the 2- to 4-year users if they were still taking oral contraceptives when entered into study. Moreover, prior biopsy for benign breast disease increased the cancer risk among long-term users by as much as 11-fold. The relative risk of breast cancer did not vary by age, interval since first use, earliest year of use, or interval since last use. These results could be interpreted to indicate that oral contraceptives did not induce breast cancer but may have accelerated the growth rate of preexisting breast cancer. The relative risk of developing benign breast disease among ever-users of oral contraceptives was 0.8 (significantly reduced); it decreased with longer duration of use until it reached 0.2 for women who took these hormones 8 years or more. The relative risk of benign breast was not affected by earliest year of use or interval since last use. We concluded that oral contraceptives reduced the incidence of benign breast disease, but that use of steroid hormones is ill-advised for women with already established benign breast disease.

Adolescent↗