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Biomedical subjects

R S Paffenbarger

Publications and source records attributed to R S Paffenbarger.

At least 19 recordsLinked to original sources
PubMed1998

Body mass index, cigarette smoking, and other characteristics as predictors of self-reported, physician-diagnosed gallbladder disease in male college alumni.

Despite the high prevalence of gallbladder disease in industrialized countries, little is known about the predictors of the disease, especially in men. The authors prospectively studied 16,785 alumni of Harvard University, aged 15-24 years, who were followed for up to 61 years. The health characteristics of these men were ascertained from their college entrance physical examination done in 1916-1950, and updated via mailed questionnaires in 1962 or 1966 (1962/1966). Alumni subsequently self-reported physician-diagnosed gallbladder disease on further mailed questionnaires in 1972 or 1977. Between college time and 1962/1966, 371 gallbladder disease cases occurred. An additional 314 cases occurred after 1962/1966. With respect to college characteristics, after adjustment for potential confounders, the authors found that body mass index (BMI), smoking, physical activity, blood pressure, and consumption of alcohol, coffee, or tea were unrelated to risk. However, BMI in 1962/1966 was directly related to risk of subsequent gallbladder disease, as was BMI gain since college (p, trend = 0.002 and 0.013, respectively). Compared with men with BMI < 22.0, men with BMI > or = 27.0 had a rate ratio of 2.71 (95% confidence interval (CI) 1.57-4.66) for risk of contracting the disease. Men who gained > or = 6.0 BMI units since college had a rate ratio of 1.46 (95% CI 0.86-2.46) compared with men who gained -0.9 to +0.9 BMI units. Compared with never smokers, men who smoked pipes or cigars or < 1 pack of cigarettes daily in 1962/1966 had a rate ratio of 1.43 (95% CI 1.00-2.06), while heavier cigarette smokers had a rate ratio of 1.52 (95% CI 1.03-2.24). Neither physical activity nor physician-diagnosed hypertension or diabetes mellitus in 1962/1966 predicted risk.

Adolescent↗
PubMed1998

Physical activity and breast cancer risk in the College Alumni Health Study (United States).

OBJECTIVES: It is unclear whether physical activity is associated with a reduced risk of breast cancer. Some studies also suggest different effects between pre- and postmenopausal women, and lean and heavy women. METHODS: We followed 1,566 University of Pennsylvania alumnae (mean age, 45.5 years), initially free of breast cancer, from 1962 until 1993. Physical activity at baseline was assessed by asking women about stairs climbed, blocks walked, and sports played. We estimated energy expenditure and categorized women into approximate thirds (< 500, 500-999, 1,000+ kcal/wk). We identified 109 breast cancer cases during 35,365 person-years from follow-up questionnaires or from death certificates. RESULTS: After adjustment for age and body mass index (BMI) (kg/m2), the relative risk (RR) of breast cancer was 0.92 (95 percent confidence interval [CI] = 0.58-1.45) among women expending 500-999 kcal/wk and 0.73 (CI = 0.46-1.14) for those expending 1,000+ kcal/wk, compared with women expending < 500 kcal/wk (P trend = 0.17). This association was modified by menopausal status, but not BMI. For postmenopausal women, corresponding RRs were 0.95 (CI = 0.58-1.57) and 0.49 (CI = 0.28-0.86), respectively (P trend = 0.015). Increased physical activity in premenopausal women was not significantly associated with decreased risk of breast cancer. CONCLUSIONS: These data support an inverse association between physical activity and breast cancer among postmenopausal women.

Adult↗
PubMed1998

Influences of cardiorespiratory fitness levels and other predictors on cardiovascular disease mortality in men.

PURPOSE: This investigation quantifies the relation between cardiorespiratory fitness levels and cardiovascular disease (CVD) mortality within strata of other CVD predictors. METHODS: Participants included 25,341 male Cooper Clinic patients who underwent a maximal graded exercise test. CVD death rates were determined for low (least fit one-fifth), moderate (next two-fifths), and high (top two-fifths) cardiorespiratory fitness categories by strata of smoking habit, blood cholesterol level, resting blood pressure, and health status. There were 226 cardiovascular deaths during 211,996 man-years of follow-up. RESULTS: For individuals with none of the major CVD predictors (smoking, elevated resting systolic blood pressure, elevated blood cholesterol), there was a strong inverse relation (P = 0.001) between fitness level and CVD mortality. An inverse relation between CVD mortality and fitness level was seen within strata of cholesterol levels and health status. No evidence of a trend (P = 0.60) for decreased mortality was seen across fitness levels for individuals with elevated systolic blood pressure; however, a strong inverse gradient (P < 0.001) was seen across fitness levels for individuals with normal systolic blood pressure. There was a tendency for association between high levels of fitness and decreased CVD mortality in smokers compared with low and moderately fit smokers (P < 0.076). There was no significant association between level of fitness and CVD mortality for individuals with multiple (two or more) predictors (P = 0.325). Approximately 20% of the 226 CVD deaths in the population studied were attributed to low fitness level. CONCLUSIONS: Moderate and high levels of cardiorespiratory fitness seem to provide some protection from CVD mortality, even in the presence of well established CVD predictors.

Adult↗
PubMed1998

Physical activity and stroke incidence: the Harvard Alumni Health Study.

BACKGROUND AND PURPOSE: Physiologically, it appears plausible for physical activity to decrease stroke risk; however, epidemiological studies have produced mixed findings. Furthermore, few studies have examined specific kinds and intensities of activities. The purpose of this study was to examine the association between physical activity, including its various components (walking, climbing stairs, participation in sports and recreational activities), and stroke risk. METHODS: This was a prospective cohort study of 11 130 Harvard University alumni (mean age, 58 years) without cardiovascular disease and cancer at baseline. Men reported their walking, stair climbing, and participation in sports or recreation on baseline questionnaires in 1977. Stroke occurrence was assessed with another questionnaire in 1988. Death certificates were obtained for decedents through 1990 to determine strokes not previously reported (total strokes=378). We used Cox proportional hazards regression to estimate the relative risks and 95% CIs for stroke occurrence associated with physical activity. RESULTS: After adjustment for age, smoking, alcohol intake, and early parental death, the relative risks of stroke associated with <1000, 1000 to 1999, 2000 to 2999, 3000 to 3999, and >/=4000 kcal/wk of energy expenditure at baseline were 1.00 (referent), 0.76 (95% CI, 0.59 to 0.98), 0.54 (0.38 to 0. 76), 0.78 (0.53 to 1.15), and 0.82 (0.58 to 1.14), respectively; P=0. 05 for linear trend. Walking >/=20 km/wk was associated with significantly lower risk, independent of other physical activity components. Climbing stairs and activities of at least moderate intensity (>/=4.5 METs, or multiples of resting metabolic rate) each showed U-shaped relations to stroke risk, with the risk being significantly lower at the nadir of the curve. Light intensity activities (<4.5 METs), however, were unrelated to stroke risk. CONCLUSIONS: Physical activity is associated with decreased stroke risk in men. A decreased risk was observed at energy expenditures of 1000 to 1999 kcal/wk, with further risk decrement seen at 2000 to 2999 kcal/wk but not beyond. Confirmation of the U-shaped relation observed in these data requires similar observations in other populations.

Aged↗
PubMed1997

Serum levels of prostate-specific antigen among Japanese-American and native Japanese men.

BACKGROUND: Fourfold to sixfold higher prostate cancer rates in Japanese-American men in the United States compared with Japanese men in Japan have been cited to support a role for environmental risk factors in the etiology of the disease. To examine the hypothesis that part or all of the elevated prostate cancer rates in Japanese-American men may reflect more intensive prostate cancer screening in the United States than in Japan, we compared prostate-specific antigen (PSA) levels in community-based samples of serum from men without prostate cancer. METHODS: Japanese-American men aged 40-85 years and native Japanese men aged 40-89 years with no history of prostate cancer provided sera, respectively, in the United States from March 1990 through March 1992 (n = 237) or in Japan from January 1992 through December 1993 (n = 3522). Age-specific PSA levels were used to estimate the prevalences of undetected prostate cancer in the two populations. RESULTS: Age-specific mean PSA levels were significantly lower in Japanese-Americans than in native Japanese (two-sided P<.001). The prevalence of an elevated PSA level increased with age in both populations and exceeded 5% among men aged 60 years or more. Combined with data on prevalence of detected prostate cancer in the two populations, our data suggest that some 10.0% of Japanese-Americans aged 75 years have prostate cancer, with 31% of that fraction remaining undiagnosed. The corresponding estimates in Japan are a total cancer prevalence of 5.4%, of which 81% has not been detected clinically. CONCLUSIONS: The total cancer prevalence ratio 10.0/5.4 = 1.9 (95% confidence interval = 1.5-2.3) in Japanese-American men compared with Japanese men in Japan suggests an increased risk for Japanese-American men, but of less magnitude than the fourfold to sixfold increase indicated by the incidence data.

Adult↗
PubMed1997

Physical activity and risk of colon cancer: the Physicians' Health Study (United States).

Previous studies indicate that physical activity is related inversely to colon cancer risk. However, details regarding that association--whether a dose-response relation exists, whether the relation differs between non-obese and obese persons, the effect of long-term physical activity--are unclear. We examined these issues in the Physicians' Health Study (United States). Physical activity was assessed at baseline among 21,807 men, aged 40 to 84 years, and again 36 months later. Men were followed for an average of 10.9 years (from baseline) during which 217 developed colon cancer. After adjusting for potential confounders (including age, obesity, and alcohol intake), the relative risks for colon cancer associated with vigorous exercise in times per week (< 1, 1, 2-4, 5+, at baseline) were 1.0 (referent); 1.1 (95% confidence interval [CI] = 0.7-1.7); 1.2 (CI = 0.8-1.6); and 1.1 (CI = 0.7-1.6), respectively; P trend = 0.6. Physical activity was not associated significantly with colon cancer risk either among non-obese or obese men. When we used physical activity assessments at baseline as well as at 36 months, physical activity again was unrelated to colon cancer risk. These data do not support the hypothesis that physical activity reduces the risk of colon cancer. Plausible alternate explanations for the null finding include misclassification of physical activity and the potential for increased surveillance for colon cancer ('screening effect') among those physically active.

Adult↗
PubMed1997

Physical activity and health of college men: longitudinal observations.

The College Alumni Health Study has examined host and environmental characteristics in youth and adult life as they relate to subsequent development of specific chronic diseases. Campus archives have provided physical, psychological, and social data on some 57,500 men and women who were born between 1896 and 1934, and who entered Harvard College or the University of Pennsylvania between 1916 and 1950, generally at age 17-20 years. These college data have been studied subsequently to assess whether characteristics in youth predisposed students to chronic diseases (nonfatal and fatal) later in life. Follow-up questionnaires, mailed to alumni, generally aged 35-85 years, in the 1960s, 1970s, 1980s, and 1990s have provided mid-life information on the health status and health habits of survivors, and official death certificates have provided data on decedents. This information has been studied, in fashion similar to the college data, for personal characteristics and ways of living that influenced health and longevity of these middle-aged and elderly men. Longitudinal observations continue today, in search of causes of specific chronic diseases.

Adolescent↗
PubMed1996

Influences of cardiorespiratory fitness and other precursors on cardiovascular disease and all-cause mortality in men and women.

OBJECTIVE: To quantify the relation of cardiorespiratory fitness to cardiovascular disease (CVD) mortality and to all-cause mortality within strata of other personal characteristics that predispose to early mortality. DESIGN--Observational cohort study. We calculated CVD and all-cause death rates for low (least fit 20%), moderate (next 40%), and high (most fit 40%) fitness categories by strata of smoking habit, cholesterol level, blood pressure, and health status. SETTING: Preventive medicine clinic. STUDY PARTICIPANTS: Participants were 25341 men and 7080 women who completed preventive medical examinations, including a maximal exercise test. MAIN OUTCOME MEASURES: Cardiovascular disease and all-cause mortality. RESULTS: There were 601 deaths during 211996 man-years of follow-up, and 89 deaths during 52982 woman-years of follow-up. Independent predictors of mortality among men, with adjusted relative risks (RRs) and 95% confidence intervals (CIs), were low fitness (RR, 1.52;95% CI, 1.28-1.82), smoking (RR, 1.65; 95% CI, 1.39-1.97), abnormal electrocardiogram (RR, 1.64;95% CI, 1.34-2.01), chronic illness (RR, 1.63;95% CI, 1.37-1.95), increased cholesterol level (RR, 1.34; 95% CI, 1.13-1.59), and elevated systolic blood pressure (RR, 1.34; 95% CI, 1.13-1.59). The only statistically significant independent predictors of mortality in women were low fitness (RR, 2.10; 95% Cl, 1.36-3.21) and smoking (RR, 1.99; 95% Cl, 1.25-3.17). Inverse gradients were seen for mortality across fitness categories within strata of other mortality predictors for both sexes. Fit persons with any combination of smoking, elevated blood pressure, or elevated cholesterol level had lower adjusted death rates than low-fit persons with none of these characteristics. CONCLUSIONS: Low fitness is an important precursor of mortality. The protective effect of fitness held for smokers and nonsmokers, those with and without elevated cholesterol levels or elevated blood pressure, and unhealthy and healthy persons. Moderate fitness seems to protect against the influence of these other predictors on mortality. Physicians should encourage sedentary patients to become physically active and thereby reduce the risk of premature mortality.

Adult↗
PubMed1995

Physical exercise and reduced risk of nonfatal myocardial infarction.

While the inverse association between physical activity and coronary heart disease risk is well documented, questions remain regarding the intensity of exercise, the potential for confounding by other risk factors for coronary heart disease, and the role of blood lipids and apolipoproteins. The authors examined these issues in the Boston Area Health Study, a case-control study of 340 patients (266 men, 74 women) who survived a first myocardial infarction between January 1, 1982, and December 31, 1983, and 340 controls matched on sex, age, and residence. The relative risk of myocardial infarction for those in the highest quartile of physical activity, compared with the lowest, was 0.50 (95 percent confidence interval (CI) 0.31-0.80) for men and 1.00 (95 percent CI 0.41-2.43) for women. When subjects were categorized by level of energy expenditure on moderate to vigorous sports alone, men in the most active category had 0.39 (95 percent CI 0.23-0.69) times the risk of those in the least active category, and women, 0.43 (95 percent CI 0.15-1.26) times the risk. Adjustment for body mass index, smoking, alcohol intake, diet, personal and family medical history, and personality type did not substantially change results nor did further adjustment for blood lipids. This was not surprising as total energy expenditure was uncorrelated with blood lipids or apolipoproteins. Moderate to vigorous sporting activity, however, appeared to be directly related to high density lipoprotein (HDL) cholesterol (p = 0.06), especially the HDL2 subfraction (p = 0.10). In these data, findings suggest that physical activity is inversely related to myocardial infarction risk, independently of other risk factors for coronary heart disease.

Adult↗
PubMed1995

Exercise intensity and longevity in men. The Harvard Alumni Health Study.

OBJECTIVE: To examine the independent associations of vigorous (> or = 6 resting metabolic rate [MET] score) and nonvigorous (< 6 MET score) physical activity with longevity. DESIGN: Prospective cohort study, following up men from 1962 or 1966 through 1988. SETTING/PARTICIPANTS: Subjects were Harvard University alumni, without self-reported, physician-diagnosed cardiovascular disease, cancer, or chronic obstructive pulmonary disease (n = 17,321). Men with a mean age of 46 years reported their physical activities on questionnaires at baseline. MAIN OUTCOME MEASURE: All-cause mortality (3728 deaths). RESULTS: Total energy expenditure and energy expenditure from vigorous activities, but not energy expenditure from nonvigorous activities, related inversely to mortality. After adjustment for potential confounders, the relative risks of dying associated with increasing quintiles of total energy expenditure were 1.00 (referent), 0.94, 0.95, 0.91 and 0.91, respectively (P [trend] < .05). The relative risks of dying associated with less than 630, 630 to less than 1680, 1680 to less than 3150, 3150 to less than 6300, and 6300 or more kJ/wk expended on vigorous activities were 1.00 (referent), 0.88, 0.92, 0.87, and 0.87, respectively (P [trend] = .007). Corresponding relative risks for energy expended on nonvigorous activities were 1.00 (referent), 0.89, 1.00, 0.98, and 0.92, respectively (P [trend] = .36). Analyses of vigorous and nonvigorous activities were mutually adjusted. Among men who reported only vigorous activities (259 deaths), we observed decreasing age-standardized mortality rates with increasing activity (P = .05); among men who reported only nonvigorous activities (380 deaths), no trend was apparent (P = .99). CONCLUSIONS: These data demonstrate a graded inverse relationship between total physical activity and mortality. Furthermore, vigorous activities but not nonvigorous activities were associated with longevity. These findings pertain only to all-cause mortality; nonvigorous exercise has been shown to benefit other aspects of health.

Adult↗