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Biomedical subjects

B Rosner

Publications and source records attributed to B Rosner.

At least 217 records · Page 12Linked to original sources
PubMed1989

A prospective study of nutritional factors and hypertension among US women.

The relation of various nutritional factors with hypertension was examined prospectively among 58,218 predominantly white US female registered nurses, aged 34-59 years. In 1980, all women completed an independently validated dietary questionnaire. During 4 years of follow-up, 3,275 women reported a diagnosis of hypertension; the validity of the self-report was shown in a subsample. Age, relative weight, and alcohol consumption were the strongest predictors for the development of hypertension. Dietary calcium and magnesium had independent and significant inverse associations with hypertension. For women with a calcium intake of at least 800 mg/day, the relative risk of hypertension was 0.78 (95% confidence interval, 0.69-0.88) when compared with an intake of less than 400 mg/day. The relative risk for magnesium intake of 300 mg/day or more compared with an intake of less than 200 mg/day was 0.77 (95% confidence interval, 0.67-0.88). For women with high intakes of both calcium and magnesium compared with those having low intakes of both, the relative risk of hypertension was 0.65 (95% confidence interval, 0.53-0.80). No independent associations with hypertension were observed for intakes of potassium, fiber, and saturated and polyunsaturated fatty acids. These prospective findings add to the growing evidence to support the need for randomized trials to determine whether there is a protective role of dietary calcium and magnesium in the regulation of blood pressure.

Adult↗
PubMed1989

Longitudinal variability in airway responsiveness in a population-based sample of children and young adults. Intrinsic and extrinsic contributing factors.

The degree and long-term variability of airway responsiveness to eucapneic hyperventilation with cold air was assessed in 287 children and young adults (less than 23 yr of age) (735 challenge tests) enrolled in a longitudinal study of pulmonary function, 179 of whom underwent two to five cold-air challenge tests between 1982 and 1986. Survey-to-survey variability in airway responsiveness was assessed with computation of adjusted within-subject correlation coefficients for continuous measures of response (percent decrease in FEV1 after challenge) and with adjusted odds ratios for dichotomous outcomes ("positive" if percent decrease FEV1 greater than or equal to 0.13). The relationships between variability in responsiveness and the following variables were examined: age, baseline level of pulmonary function, presence of respiratory symptoms and illnesses, smoking exposures, season, level of ventilation achieved during testing, and temperature of the expired air. Airway hyperresponsiveness was demonstrated consistently over all surveys in only six of 49 (12%) subjects who had ever demonstrated a "positive" airway response. The odds relating positive responses between surveys was 12.1 for airway hyperresponsiveness, 21.5 for "persistent" wheeze, and 6.7 for "any" wheeze. Significant predictors of airway hyperresponsiveness were wheeze symptoms (OR = 2.3), hay fever (OR = 1.6), and a chest illness requiring bed rest (OR = 2.5). Adjustment for survey-to-survey differences in respiratory symptoms, or for differences in testing conditions between surveys, did not alter the observed variability in airway responsiveness. Adjustment for "random error" (assessed with replicate measures of airway responsiveness in a subsample of 21 subjects) improved the observed survey-to-survey variability by 30%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Effects of blood transfusion and cyclosporin on rabbit corneal graft survival.

Blood transfusion prolongs renal, cardiac, and skin allograft survival, but promotes rejection of bone marrow allografts. At present, it is unclear whether transfusion induces allograft tolerance or sensitization in corneal transplants. We performed eccentric penetrating keratoplasty on New Zealand albino rabbits, using Dutch rabbits as donors. Twenty-four recipient rabbits were randomly allocated into four groups. The control group received no pretreatment. The other three groups received a donor-specific whole-blood transfusion and/or cyclosporin seven days before the corneal transplants. A single blood transfusion accelerated allograft rejection by an average of 8.8 days (p = 0.0005). In contrast, a single cyclosporin pretreatment prolonged graft survival by an average of 5.3 days (p = 0.02). There was no evidence of interaction effects between transfusion and cyclosporin (p = NS). Therefore, unlike renal, cardiac, and skin allografts and similar to bone marrow allografts, prior blood transfusion accelerates corneal allograft rejection in our rabbit model. Although our data can not be extrapolated to human corneal transplants, our results raise the question whether blood transfusion can sensitize humans to corneal allografts.

Animals↗
PubMed1988

Cigarette smoking and risk of stroke in middle-aged women.

It is known that cigarette smoking is associated with increased risk of both thrombotic and hemorrhagic stroke among men. To test for such an association among women, we examined the incidence of stroke in relation to cigarette smoking in a prospective cohort study of 118,539 women 30 to 55 years of age and free from coronary heart disease, stroke, and cancer in 1976. During eight years of follow-up (908,447 person-years), we identified 274 strokes, comprising 71 subarachnoid hemorrhages, 26 intracerebral hemorrhages, 122 thromboembolic strokes, and 55 strokes about which information was insufficient to permit classification. The number of cigarettes smoked per day was associated positively with the risk of stroke. Compared with the women who had never smoked, those who smoked 1 to 14 cigarettes per day had an age-adjusted relative risk of 2.2 (95 percent confidence interval, 1.5 to 3.3), whereas those who smoked 25 or more cigarettes per day had a relative risk of 3.7 (95 percent confidence interval, 2.7 to 5.1). For women in this latter group, the relative risk of subarachnoid hemorrhage was 9.8 (95 percent confidence interval, 5.3 to 17.9), as compared with those who had never smoked. Adjustment for the effects of relative weight, hypertension, diabetes, history of high cholesterol, previous use of oral contraceptives, postmenopausal estrogen therapy, and alcohol intake did not appreciably alter the association between cigarette use and incidence of stroke. These prospective data support a strong causal relation between cigarette smoking and stroke among young and middle-aged women.

Adult↗
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

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

Interval estimates for correlation coefficients corrected for within-person variation: implications for study design and hypothesis testing.

It is well known that random measurement error can attenuate the correlation coefficient between two variables. One possible solution to this problem is to estimate the correlation coefficient based on an average of a large number of replicates for each individual. As an alternative, several authors have proposed an unattenuated (or corrected) correlation coefficient which is an estimate of the true correlation between two variables after removing the effect of random measurement error. In this paper, the authors obtain an estimate of the standard error for the corrected correlation coefficient and an associated 100% x (1-alpha) confidence interval. The standard error takes into account the variability of the observed correlation coefficient as well as the estimated intraclass correlation coefficient between replicates for one or both variables. The standard error is useful in hypothesis testing for comparisons of correlation coefficients based on data with different degrees of random error. In addition, the standard error can be used to evaluate the relative efficiency of different study designs. Specifically, an investigator often has the option of obtaining either a few replicates on a large number of individuals, or many replicates on a small number of individuals. If one establishes the criterion of minimizing the standard error of the corrected coefficient while fixing the total number of measurements obtained, in almost all instances it is optimal to obtain no more than five replicates per individual. If the intraclass correlation is greater than or equal to 0.5, it is usually optimal to obtain no more than two replicates per individual.

Biometry↗
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

Standardization and analysis of digitized photographic data in the longitudinal documentation of cataractous growth.

Age-related cataract formation in man can be documented with slit and retroillumination photographs. With digitization and image analysis of such photographs a cataract may be characterized by a frequency distribution of picture elements over a 255 step gray scale spectrum. Transition from a clear to a cataractous lens may be manifested as a change from a unimodal, Gaussian to a multimodal, non Gaussian frequency distribution respectively. How should one compare and contrast these two distributions, so to accurately describe the extent and significance of a change in lens opacification? The in vitro system of cold cataract formation in the rabbit lens was used as a model of the much slower process of age-related cataract formation in man. As in the human lens undergoing progressive opacification, the frequency distribution (number of pixels vs. intensity of gray) for a digitized image of a clear lens at 26 degrees C is unimodal and Gaussian; that of a fully developed cold cataract at 10 degrees C is multimodal and non-gaussian. In spite of the increasing multimodality of the frequency distribution as the temperature dropped and the cataract grew in density and size, the mean gray density proved to be a valid and useful measure to characterize the distribution and to compare different unaligned images. The Wilcoxon Rank Sum Test proved to be useless in comparing the frequency distributions from cataract images because it proved to be too sensitive to subtle changes in the degree of opacification. Anomalous behavior of the opacification process--i.e. clarification as well as opacification of the lens during cold cataract formation caused all pairs to appear statistically significantly different when in appearance there was no difference. The mean of the frequency distribution is less sensitive to this anomalous behavior and is useful as a comparative index. The method of calculating the threshold of significant change in the mean density of a cataract image is presented.

Animals↗
PubMed1988

Significance testing for correlated binary outcome data.

Multiple logistic regression is a commonly used multivariate technique for analyzing data with a binary outcome. One assumption needed for this method of analysis is the independence of outcome for all sample points in a data set. In ophthalmologic data and other types of correlated binary data, this assumption is often grossly violated and the validity of the technique becomes an issue. A technique has been developed (Rosner, 1984) that utilizes a polychotomous logistic regression model to allow one to look at multiple exposure variables in the context of a correlated binary data structure. This model is an extension of the beta-binomial model, which has been widely used to model correlated binary data when no covariates are present. In this paper, a relationship is developed between the two techniques, whereby it is shown that use of ordinary logistic regression in the presence of correlated binary data can result in true significance levels that are considerably larger than nominal levels in frequently encountered situations. This relationship is explored in detail in the case of a single dichotomous exposure variable. In this case, the appropriate test statistic can be expressed as an adjusted chi-square statistic based on the 2 X 2 contingency table relating exposure to outcome. The test statistic is easily computed as a function of the ordinary chi-square statistic and the correlation between eyes (or more generally between cluster members) for outcome and exposure, respectively. This generalizes some previous results obtained by Koval and Donner (1987, in Festschrift for V. M. Joshi, I. B. MacNeill (ed.), Vol. V, 199-224.(ABSTRACT TRUNCATED AT 250 WORDS)

Biometry↗
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

Occupation and risk of death from coronary heart disease.

Conflicting data have been reported regarding the association between occupation and coronary heart disease. We evaluated data on a series of 568 married men who died of coronary heart disease and an equal number of controls matched for age, sex, and neighborhood of residence. Information was collected from the wives of both cases and controls on a larger number of variables, including usual occupation, job-related and leisure-time physical activity, medical history, and life-style. Usual occupation was dichotomized into blue-collar and white-collar work according to the Edwards' classification. White-collar workers had a statistically significant 30% decreased risk of fatal coronary heart disease compared with blue-collar workers once the effects of reported coronary risk factors were considered (relative risk, 0.70; 95% confidence limits, 0.5 to 0.96). These data suggest that occupation is significantly associated with fatal coronary heart disease, and that this increased risk is not explained by a large number of known coronary risk factors. It still remains unclear, however, whether other uncontrolled variables explain the observed association.

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

Increased plasma free cortisol in ocular hypertension and open angle glaucoma.

Values of plasma free cortisol (not bound to plasma proteins), total plasma cortisol, and percent free cortisol were determined in normal, ocular hypertensive, and open angle glaucomatous subjects. Median total plasma, plasma free, and percent free cortisol levels were higher in ocular hypertensive and glaucomatous individuals. The most significant differences occurred with percent free cortisol values between normal and glaucomatous subjects. There was a significant positive correlation between percent free cortisol and total cortisol levels in normal subjects only. For subjects with glaucoma and hypertension, the percent free cortisol values were independent of the total cortisol values. Multilinear regression analysis also indicated that besides diagnosis and level of total plasma cortisol, male sex, blood sampling late in the day, and increased diastolic blood pressure were the only variables significantly related to increased values of plasma free cortisol and percent free cortisol. Ocular medication for glaucoma and use of beta-blockers were not found to be significant independent variables in the regression models for either plasma free cortisol or percent free cortisol. These observations further suggest that a disorder of the pituitary adrenal axis and/or a binding of plasma cortisol is associated with ocular hypertension and open angle glaucoma.

Adrenergic beta-Antagonists↗
PubMed1987

Genetic and environmental control of blood pressure in twins and their family members.

An interdisciplinary study, in adult twins and their family members, of the genetic and environmental determinants of complex physiologic functions is in progress. This report summarizes our initial studies of the control of the level of systolic (K1) and diastolic (K5) blood pressure in 202 monogygotic (MZ) and 121 dizygotic (DZ) twins, their spouses and their children. Correlation coefficients for blood pressure were adjusted for the covariates age, sex, body mass index (wt/ht2) and screener, all of which significantly augment most correlations. These adjusted correlation coefficients in MZ twins are 0.5 for both K1 and K5 blood pressure. For DZ twins, the adjusted correlation coefficients are 0.21 (K1) and 0.24 (K5). MZ twin-offspring adjusted correlation coefficients are higher than MZ twin-niece/nephew adjusted correlation coefficients (0.12 and 0.06, respectively, for K1; 0.20 and 0.13, respectively, for K5), despite the genetic identity of these relationships. That environmental factors may explain these differences is suggested by other differences in adjusted correlation coefficients that are greater than those predicted by the degree of genetic similarity. In addition, we have assessed the relationship between two biochemical-physiological processes, the urinary excretion of kallikrein and transport of sodium in the erythrocyte (the sodium countertransport and the sodium-potassium-chloride cotransport systems), and blood pressure control, since both have been implicated in the control of blood pressure level. Although we found evidence for substantial genetic control of both phenomena, we were unable to establish any correlation between either function and the level of blood pressure in our normotensive subjects. These data point to the operation of three broad categories of control of level of blood pressure: constitutional factors (age, sex, body mass), genetic factors and environmental factors. The identities of the genetic and environmental factors are unknown at this time.

Adolescent↗