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Biomedical subjects

M J Stampfer

Publications and source records attributed to M J Stampfer.

At least 451 records · Page 25Linked to original sources
PubMed1988

Energy intake and other determinants of relative weight.

The relationships of relative weight to energy intake and to physical activity were studied among 141 females aged 34-59 y. As observed in previous studies Quetelet index (wt/ht2) was inversely related to energy intake (r = -0.11). However, obese women tended to be older (r = 0.16), exercise less (r = -0.30), and drink less alcohol (r = -0.16) than nonobese women. Older women had lower energy intake (r = -0.23) and exercised less (r = -0.12) than younger women. Energy intake and physical activity were positively related (r = 0.23). After adjustment for age, physical activity, alcohol, and smoking, the inverse correlation between relative weight and energy intake was significantly reduced (p = 0.04) from r = -0.11 to r = -0.02. Obese women reported higher intakes of total fat, and relative weight was significantly correlated with intakes of total fat (r = 0.20) and saturated fatty acids (r = 0.16). These data highlight the importance of considering factors that may confound the relationship between energy intake and obesity, and they suggest that fat intake may play a role in obesity that is independent of total energy intake.

Adult↗
PubMed1988

Vitamin E supplementation effect on human platelet function, arachidonic acid metabolism, and plasma prostacyclin levels.

A randomized, placebo-controlled double-blind trial was conducted on 20 adults to assess the effect of vitamin E (800 IU/d 727 mg/d for 5 wk) on platelet function, arachidonic acid metabolism, and prostacyclin generation. Platelet aggregation was measured in response to collagen, arachidonic acid, and adenosine diphosphate. Thromboxane B2 was assayed in serum and in the supernatant plasma after platelet aggregation. Platelets were labeled with [3H]arachidonic acid to assess production and release of cyclooxygenase products (MDA, TXB2, and HHT), a lipoxygenase product (12-HETE), and arachidonic acid in response to stimulation by thrombin or collagen. Prostacyclin was measured in plasma and in blood collected from bleeding-time incisions by a sensitive HPLC-RIA procedure. Despite marked increases in plasma and erythrocyte vitamin E levels in the vitamin E group, there were no significant differences between the vitamin E and placebo groups in any of the variables measured.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1988

The use of a self-administered questionnaire to assess diet four years in the past.

The use of a mailed, self-administered, semiquantitative food frequency questionnaire to describe past dietary intake was evaluated in 1984 among a group of 150 Boston-area women who had completed four one-week diet records three to four years previously. Correlation coefficients comparing calorie-adjusted nutrient intakes computed from the questionnaire with those obtained from a compressed version of the questionnaire completed during diet record keeping ranged from 0.44 for total carbohydrate to 0.62 for vitamin C including supplements. Coefficients comparing calorie-adjusted nutrient intakes measured by questionnaire with those assessed by the diet records completed three to four years previously ranged from 0.28 for iron without supplements to 0.61 for total carbohydrate. An evaluation of the incremental contribution provided by several open-ended sections of the questionnaire to the estimation of nutrient intake suggested that in this population most of these items might be eliminated without material loss of information. These findings demonstrate that useful estimates of nutrient intake several years previously can be obtained by a relatively inexpensive, mailed, self-administered questionnaire.

Adult↗
PubMed1988

The relation of diet, cigarette smoking, and alcohol consumption to plasma beta-carotene and alpha-tocopherol levels.

The relation of diet and nutritional supplements, cigarette use, alcohol consumption, and blood lipids to plasma levels of beta-carotene and alpha-tocopherol was studied among 330 men and women aged 18-79 years. Dietary carotene, preformed vitamin A, and vitamin E intake were estimated by a self-administered semiquantitative food frequency questionnaire. The correlation of dietary carotene with plasma beta-carotene was reduced in smokers compared with nonsmokers (r = 0.02 vs. 0.44 among men; r = 0.19 vs. 0.45 among women). Smokers had much lower plasma levels of beta-carotene than did nonsmokers (geometric mean 8.5 vs. 15.3 micrograms/dl for men; 17.3 vs. 26.3 micrograms/dl for women) despite only slightly lower intakes of carotenoids. In multiple regression analyses, men who smoked one pack per day had 72% (95% confidence interval (CI) 58-89) of the plasma beta-carotene levels of nonsmokers after accounting for dietary carotene and other variables; for women, the corresponding percentage was 79% (CI 64-99). In similar models, men drinking 20 g of alcohol per day had 76% (CI 65-88) of the beta-carotene levels of nondrinkers; women had 89% (CI 73-108) of the levels of nondrinkers. An interaction term for carotene intake and smoking was statistically significant in a model combining both sexes. These results suggest that plasma levels of beta-carotene among smokers and, perhaps, heavy consumers of alcohol may be reduced substantially below levels due to differences in diet. The correlation of calorie-adjusted intake of vitamin E with lipid-adjusted plasma levels of vitamin alpha-tocopherol was 0.53 for men (n = 137) and 0.51 for women (n = 193) and did not differ by alcohol consumption and cigarette use; these correlations were largely accounted for by use of vitamin supplements. In linear regression models, vitamin E intake and plasma lipids were significant predictors of plasma alpha-tocopherol levels.

Adolescent↗
PubMed1988

Self-reports of mole counts and cutaneous malignant melanoma in women: methodological issues and risk of disease.

The relation of the presence of moles (nevi) on all four limbs to risk of cutaneous malignant melanoma was explored among 98 incident cases aged 32-59 years at diagnosis and 190 age-matched controls drawn from the Nurses' Health Study, a prospective cohort of female nurses in the United States. Cases diagnosed during follow-up from 1976 to 1982 were included in this study. Participants reported counts of all moles and raised moles alone on postal questionnaires. Distributions of moles were similar for right and left sides on upper and lower limbs for cases and controls. Counts declined with increasing age for all women, from a median of 15 for the youngest tertile of controls (aged 36-46 years) to three for the oldest (aged 54-62 years). Cases had more moles than did controls (medians of 23 and 9, respectively, for total moles on all four limbs): The presence of any mole on a limb gave relative risks for melanoma ranging from 2.2 (95% confidence interval (CI) = 1.2-4.0) for one or more moles on an arm to 2.9 (95% CI = 1.6-5.3) for one or more moles on the lower limb. For raised moles, relative risks were 1.7 (95% CI = 1.0-2.7) for arm, 2.1 (95% CI = 1.3-3.5) for lower limb, and 3.5 (95% CI = 2.0-6.3) for leg (below knee). The highest site-specific risk (i.e., for any moles on the same limb as the melanoma vs. no moles on that limb) was for moles on the lower limb (relative risk = 5.0 (95% CI = 1.8-13.5)). There were positive and significant trends in overall and site-specific risk with increasing numbers of moles on all limbs when absolute mole counts were considered, e.g., for total moles on all four limbs combined, chi for trend = 4.0, one-sided p less than 0.001, with relative risk for more than 100 moles versus none of 6.0. Inclusion of sun exposure and other constitutional factors in logistic regression analyses did not alter these observed relations between the presence of moles and risk of melanoma.

Adult↗
PubMed1988

Variability in portion sizes of commonly consumed foods among a population of women in the United States.

The use of food frequency questionnaires for measuring dietary intake has become widespread in epidemiologic studies. It has been suggested that inquiring about a person's usual serving size of each food, in addition to the frequency of consumption, will improve the accuracy of this method. This approach implies that individuals characteristically eat a specific amount of any particular food, and that this amount can be reported with reasonable accuracy. To investigate the variability of portion sizes, the authors analyzed data for 68 commonly consumed foods, based on four one-week weighed diet histories recorded by 194 Boston-area women aged 34-59 years during 1980 and 1981. For each food, total population variance in portion size was partitioned into within-person (intraindividual) and between-person (interindividual) components. For all but seven food items (yogurt, liver, mixed vegetables, watermelon, pancakes/waffles, cold cereal, and cooked cereal) the within-person variance in portion size exceeded the between-person variance. The mean of the within-person to between-person variance ratios, after exclusion of two outlying foods, was 3.4 for untransformed portion sizes, and 3.2 after portion sizes were loge-transformed. Foods with a high within-person variance also tended to have a high between-person variance. The dominance of within-person variance in portion sizes suggests that the concept of usual portion size is complex, and that subjects may experience substantial difficulty in specifying their "usual" portion size. The smaller contribution of between-person variance to the total variance in portion size suggests that specification of a standard portion size by the investigator may not introduce a large error in the estimation of food and nutrient intake.

Adult↗
PubMed1988

A prospective study of moderate alcohol drinking and risk of diabetes in women.

Several investigators have observed an association between alcohol consumption and elevated glucose levels, raising the possibility that alcohol may increase the risk of diabetes. This hypothesis was evaluated prospectively among 85,051 women participating in the Nurses' Health Study who were 34 to 59 years of age in 1980 and had no history of cancer, coronary heart disease, or diabetes. At baseline, participants completed an independently validated dietary questionnaire which included information on the consumption of beer, wine, and liquor. Incident cases of non-insulin-dependent diabetes were reported on follow-up questionnaires sent in 1982 and 1984 (98% response to at least one follow-up); 526 cases were confirmed by a supplementary questionnaire regarding symptoms, laboratory values, and treatment. The risk of diabetes decreased monotonically with increasing alcohol consumption (chi trend = -9.4, p less than 0.0001). Compared with nondrinkers, women consuming 5-14.9 g of alcohol per day (about 4-10 drinks per week) had an age-adjusted relative risk of diabetes of 0.4 (95% confidence interval (CI) 0.3-0.6); for 15 g or more per day, the relative risk was 0.3 (95% CI 0.2-0.4). However, a strong inverse association between alcohol drinking and body weight explained much of the apparent protective effect of alcohol. After simultaneous adjustment for Quetelet index (weight (kg)/height (m)2), family history of diabetes, total caloric intake, and age, the relative risk of diabetes for consumers of 5-14.9 g per day was 0.8 (95% CI 0.6-1.2), and for women who drank 15+ g per day, the relative risk was 0.6 (95% CI 0.3-0.9). These data provide no support for the hypothesis that moderate alcohol intake increases the risk of non-insulin-dependent diabetes.

Adult↗
PubMed1988

Fractures and lifestyle: effect of cigarette smoking, alcohol intake, and relative weight on the risk of hip and forearm fractures in middle-aged women.

Cigarette smoking, alcohol consumption and low relative weight are often cited as risk factors for osteoporosis. In a prospective cohort study of 96,508 middle-aged nurses 35 to 59 years of age we found that smoking was not a risk factor for hip and forearm fracture. Women who drank more than 15 grams of alcohol per day and whose relative weight was less than 21 kg/m2 were at increased risk of fractures, but these risk factors were not independent. Only the combination of alcohol intake and thinness substantially increased the likelihood of fracture. The low weight women consuming more than one drink per day comprised but 4 per cent of our population of middle-class women and sustained 6 per cent of the fractures.

Adult↗
PubMed1987

Relative and absolute excess risks of coronary heart disease among women who smoke cigarettes.

We prospectively examined the incidence of coronary heart disease in relation to cigarette smoking in a cohort of 119,404 female nurses who were 30 to 55 years of age in 1976 and were free of diagnosed coronary disease. During six years of follow-up, 65 of the women died of fatal coronary heart disease and 242 had a nonfatal myocardial infarction. The number of cigarettes smoked per day was positively associated with the risk of fatal coronary heart disease (relative risk = 5.5 for greater than or equal to 25 cigarettes per day), nonfatal myocardial infarction (relative risk = 5.8), and angina pectoris (relative risk = 2.6). Even smoking 1 to 4 or 5 to 14 cigarettes per day was associated with a twofold to three-fold increase in the risk of fatal coronary heart disease or nonfatal infarction. Overall, cigarette smoking accounted for approximately half these events. The attributable (absolute excess) risk of coronary heart disease due to current smoking was highest among women who were already at increased risk because of older age, a parental history of myocardial infarction, a higher relative weight, hypertension, hypercholesterolemia, or diabetes. In contrast, former smokers had little, if any, increase in risk. These prospective data emphasize the importance of cigarette smoking as a determinant of coronary heart disease in women, as well as the markedly increased hazards associated with this habit in combination with other risk factors for this disease.

Adult↗
PubMed1987

Moderate alcohol consumption and the risk of breast cancer.

In 1980, 89,538 U.S. women 34 to 59 years of age, with no history of cancer, completed an independently validated dietary questionnaire that included the use of beer, wine, and liquor. During the ensuring four years, 601 cases of breast cancer were diagnosed among cohort members. Among the women consuming 5 to 14 g of alcohol daily (about three to nine drinks per week), the age-adjusted relative risk of breast cancer was 1.3 (95 percent confidence limits, 1.1 and 1.7). Consumption of 15 g of alcohol or more per day was associated with a relative risk of 1.6 (95 percent confidence limits, 1.3 and 2.0; Mantel extension chi for linear trend = +4.2; P less than 0.0001). Adjustment for known breast cancer risk factors and a variety of nutritional variables did not materially alter this relation. Significant associations were observed for beer and liquor when considered separately. Among women without risk factors for breast cancer who were under 55 years of age, the relative risk associated with consumption of 15 g of alcohol or more per day was 2.5 (95 percent confidence limits, 1.5 and 4.2). These prospective data derived from measurements of alcohol intake recorded before the diagnosis of breast cancer confirm the findings of several previous case-control studies. Viewed collectively, they suggest that alcohol intake may contribute to the risk of breast cancer.

Adult↗
PubMed1987

Menopause and the risk of coronary heart disease in women.

To determine the relation of menopause to the risk of coronary heart disease, we analyzed data on a prospective cohort of 121,700 U.S. women 30 to 55 years old who were followed from 1976 to 1982. Information on menopausal status, the type of menopause, and other risk factors was obtained in 1976 and updated every two years by mailing questionnaires. Through 1982, the follow-up rate was 98.3 percent for mortality and 95.4 percent for nonfatal events. After we controlled for age and cigarette smoking, women who had had a natural menopause and who had never taken replacement estrogen had no appreciable increase in the risk of coronary heart disease, as compared with premenopausal women (adjusted rate ratio, 1.2; 95 percent confidence limits, 0.8 and 1.8). Again compared with premenopausal women, the occurrence of a natural menopause together with the use of estrogens did not affect the risk (rate ratio, 0.8, 95 percent confidence limits, 0.4 and 1.3). Women who had undergone bilateral oophorectomy and who had never taken estrogens after menopause had an increased risk (rate ratio, 2.2; 95 percent confidence limits, 1.2 and 4.2). However, the use of estrogens in the postmenopausal period appeared to eliminate this increased risk among these women as compared with premenopausal women (rate ratio, 0.9; 95 percent confidence limits, 0.6 and 1.6). These data suggest that, in contrast to a natural menopause, bilateral oophorectomy increases the risk of coronary heart disease. This increase appears to be prevented by estrogen-replacement therapy.

Adult↗
PubMed1987

Body weight and longevity. A reassessment.

Conflicting results have been reported concerning the association between body weight and longevity. The shape of the curve relating weight to all-cause mortality has been variously described as linear, J-shaped, and even U-shaped. To assess the validity of the evidence for optimal weight recommendations, we examined the 25 major prospective studies on the subject. Each study had at least one of three major biases: failure to control for cigarette smoking, inappropriate control of biologic effects of obesity, such as hypertension and hyperglycemia, and failure to control for weight loss due to subclinical disease. The presence of these biases leads to a systematic underestimate of the impact of obesity on premature mortality. Although these biases preclude a valid assessment of optimal weight from existing data, available evidence suggests that minimum mortality occurs at relative weights at least 10% below the US average.

Body Weight↗
PubMed1987

Dietary fat and the risk of breast cancer.

Dietary fat has been suggested as a risk factor for breast cancer in women, but the available data on humans are sparse and inconsistent. In 1980, 89,538 U.S. registered nurses who were 34 to 59 years of age and had no history of cancer completed a previously validated dietary questionnaire designed to measure individual consumption of total fat, saturated fat, linoleic acid, and cholesterol, as well as other nutrients. In a subsample of 173 participants studied in detail, those in the highest quintile of fat intake consumed a mean of 44 percent of calories from fat, as compared with 32 percent for those in the lowest quintile. During four years of follow-up, 601 cases of breast cancer were diagnosed among the 89,538 nurses in the study. After adjustment for known determinants in multivariate analyses, the relative risk of breast cancer among women in the highest quintile of calorie-adjusted total fat intake, as compared with women in the lowest quintile, was 0.82 (95 percent confidence limits, 0.64 and 1.05). The corresponding relative risks were 0.84 (confidence limits, 0.66 and 1.08) for saturated fat, 0.88 (0.69 and 1.12) for linoleic acid, and 0.91 (0.70 and 1.18) for cholesterol intake. Similar results were found for both postmenopausal and premenopausal women. These data are based on a limited period of follow-up and do not exclude a possible influence of fat intake before adulthood or at levels lower than 30 percent of calories. They suggest, however, that a moderate reduction in fat intake by adult women is unlikely to result in a substantial reduction in the incidence of breast cancer.

Adult↗
PubMed1987

Diet and lung cancer. A review of the epidemiologic evidence in humans.

We reviewed the human epidemiologic studies of the possible protective effect against lung cancer of various dietary constituents, including preformed vitamin A, carotene, vitamin E, selenium, and vitamin C. Beta carotene has strong potential as a protective agent, though constituents of green and yellow vegetables other than carotene may account for the reduced cancer incidence observed in many studies. Selenium also deserves attention as a potential chemopreventive nutrient, though data are limited. Data on vitamin E are sparse and inconclusive, and there is little evidence that vitamin C provides protection against human lung cancer. It is likely that cessation of cigarette smoking would have a far greater influence on reducing lung cancer incidence than any known dietary modification.

Ascorbic Acid↗
PubMed1987

Nonspecific electrocardiographic abnormality as a predictor of coronary heart disease: the Framingham Study.

The risk of developing overt coronary heart disease is examined in relation to occurrence of non-specific electrocardiographic S-T and T-wave abnormalities (NSA-ECG) in the Framingham Study. In the course of follow-up, 14% of the 5127 men and women had or developed NSA-ECG without clinically apparent intervening coronary heart disease. During 30 years of surveillance, 760 men and 578 women developed a first overt clinical manifestation of coronary heart disease. NSA-ECG appears to be a hallmark of a compromised coronary circulation which predicted the occurrence of every clinical manifestation of coronary heart disease independently of known risk factors including hypertension, its chief determinant. Coronary morbidity and mortality was increased twofold in each sex. The more common T-wave abnormality alone carried a significant increased risk, although the combination of S-T and T-wave seemed most hazardous. Persons who develop NSA-ECG without other explanation warrant vigorous preventive management against coronary heart disease.

Adult↗
PubMed1987

Effect of linoleic and oleic acids on blood pressure, blood viscosity, and erythrocyte cation transport.

It has been proposed that dietary linoleic acid lowers blood pressure (BP) by being converted to arachidonic acid and prostanoids of the two-ene series. We tested the effects of linoleic acid on plasma arachidonic acid, blood pressure, blood viscosity, and RBC cation transport. Oleic acid, the major dietary monounsaturated fat and which is not a prostanoid precursor, was used as a control. Seventeen adults consumed 23 g/d of linoleic acid or oleic acid provided by genetic variants of safflower seed, each for 4 weeks in a double-blind crossover design. Linoleic and oleic acids were enriched significantly in the plasma cholesteryl esters, phospholipids and triglycerides during the respective periods of supplementation but there was no increase in arachidonate. Mean BP was 116.1/76.8 during ingestion of oleic and 113.6/74.6 during ingestion of linoleic acid (p = 0.09 systolic, p = 0.12 diastolic). The power of the study was over 75% for detecting a significant (p less than 0.05) effect of 4 mm Hg in systolic BP or diastolic BP. Whole blood and plasma viscosity, and RBC Li/Na countertransport, Na/K cotransport, and Na pump systems (Vmax) were unchanged during the protocol. Therefore, variations in dietary linoleic or oleic acids are unlikely to have major effects on BP or on several membrane-dependent erythrocyte functions related to hypertension.

Adult↗
PubMed1987

Reproducibility and validity of self-reported menopausal status in a prospective cohort study.

The reproducibility and validity of self-reported menopausal status were evaluated among the 121,700 female US registered nurses aged 30-55 years in 1976 who are participants in the Nurses' Health Study, a prospective cohort study of diseases in women. When questioned in 1978, 6,591 of the women who were premenopausal in 1976 reported that their menses had ceased and provided their age at menopause. Two years later, in 1980, 98.8 per cent of the 6,591 women again reported that they were postmenopausal and again gave the reasons for menopause (natural or surgical). Among those women who reported surgical menopause during the 1976-1978 follow-up interval, age at menopause was reported to within one year on both the 1978 and 1980 questionnaires by 95 per cent of women. Among those reporting natural menopause during the 1976-1978 period, 82 per cent of women reported their age at menopause to within one year on the two follow-up questionnaires. A random sample of 255 women reporting surgical menopause between 1982 and 1984 was identified and medical records were obtained for 200. For all but two women, there was complete agreement between self-report and medical record for details of hysterectomy and extent of ovarian surgery. The reproducibility of self-reported age at menopause was assessed among 31,405 women who were menopausal in 1976. Reported age at menopause on consecutive questionnaires showed increasing within-person variance with increasing duration since menopause.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗