Search PubMed⌕ Search

Biomedical subjects

S T Weiss

Publications and source records attributed to S T Weiss.

At least 181 records · Page 10Linked to original sources
PubMed1993

Airway responsiveness in young black and white women.

The prevalence and severity of asthma appears to be greater in blacks than in whites. To determine if racial differences in airway responsiveness may explain these findings, methacholine challenge tests from 62 black and 238 white women 20 to 35 yr of age were evaluated. Subjects served as controls for a case-control study of the relation of airway responsiveness and preterm labor. Standardized questionnaires were used to obtain information on age, obstetrical history, education, income, cigarette smoking, medication use, and respiratory illnesses and symptoms. Total serum IgE was measured using a radioimmunoassay. Methacholine challenge testing was performed on all subjects 6 wk after delivery, and the provocative dose causing a 20% decrease in FEV1 (PD20) was calculated. Black women in the study had more pregnancies and children, were younger, less well educated and more impoverished, and reported greater cigarette smoking and less medication use than did the white women. Additionally, black women had higher geometric mean serum IgE levels (blacks: 65.4 IU versus whites: 20.0 IU; p < 0.001), lower FEV1 (blacks: 2.73 +/- 0.38 SD L versus whites: 3.19 +/- 0.39 L; p < 0.001), and greater unadjusted airway responsiveness than did white women (geometric mean PD20: blacks: 28.4 mumol versus whites: 38.8 mumol; p = 0.02). After adjusting for selective demographic and smoking differences, a significant additional effect of race on mean PD20 was found. However, after adjustment for level of serum IgE and level of FEV1, racial differences were no longer apparent.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Long-term variability of bronchial responsiveness to histamine in a random population sample of adults.

Long-term variability of bronchial responsiveness has been studied in a random population sample of adults. During a follow-up period of 18 yr, 2,216 subjects contributed 5,012 observations to the analyses. Each subject could have as many as seven observations. Bronchial responsiveness was assessed with a histamine challenge test. The threshold value was defined as the concentration of histamine that caused a decrease in FEV1 of 10% of more (PC10). After a 3-yr interval, a change of the threshold value with two or more doubling concentrations occurred in 21% of the subjects. This proportion increased to 43% if the time between two measurements increased to 18 yr. Of all subjects with multiple observations, 41% were always nonresponders (PC10 > or = 32 mg/ml), 11% were always responders (PC10 < or = 16 mg/ml), and 48% changed responder status. Of the subjects with greater than three observations, 65% changed responder status. Regression analyses, stratified by symptom status, sex, and smoking habit, were used to estimate intraclass correlation coefficients (ICC) as a measure of variability of responsiveness. On average, ICC values were low (0.40), also indicating considerable variability. With adjustment for FEV1, age, area of residence, and eosinophil count, the ICC values decreased slightly. This indicated that with adjustment, the total variability decreased more than the within-subject variability. ICC values did not differ significantly between asymptomatic and symptomatic subjects. Analyses of responsiveness as a binary variable revealed similar results.

Adolescent↗
PubMed1993

Seasonal and allergenic predictors of bronchial responsiveness to distilled water.

To evaluate a possible seasonal change in bronchial responsiveness and the relation of such change to atopy, we administered 2,537 bronchial challenge tests in winter and spring to a dynamic population cohort of children 7 to 10 yr of age. The bronchial challenge test consisted of 10 min of tidal inhalation of an aerosol of ultrasonically nebulized distilled water; the resulting percentage decrease in FEV1 (dFEV1%) was recorded. Atopy was determined on the basis of skin-test positivity (any wheal with a diameter greater than that obtained with a positive control) to seven allergens (cat dander, dog dander, house-dust mite, birch, raygrass, orchard grass, and Alternaria). Greater bronchial responsiveness in winter was independently and significantly predicted by a physician's diagnosis of asthma (difference in dFEV1%, 5.6; 95% confidence intervals [95% CI], 2.8 to 8.5; p = 0.0001) and by shortness of breath (difference in dFEV1%, 4.2; 95% CI, 2.1 to 6.3; p = 0.0001). These factors were also predictive of greater responsiveness in the spring, as was atopy (difference in dFEV1%, 3.2; 95% CI, 1.8 to 4.6; p = 0.0001). Analysis of specific allergens further revealed that reactivity to perennial allergens (house-dust mite, cat dander) was predictive of bronchial responsiveness in both winter and spring. However, the change in responsiveness between seasons was most significantly predicted by allergy to seasonal grass pollen, i.e., ragweed or orchard grass (change in dFEV1%, 2.6; 95% CI, 0.6 to 4.5; p = 0.01). In summary, our study demonstrates increased bronchial responsiveness in spring among children allergic to grass pollen.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗
PubMed1993

Risk factors for the persistence of respiratory symptoms in childhood asthma.

We studied the prognosis of childhood asthma in a cohort of 406 children 8 to 12 yr of age when enrolled. Subjects were followed for a mean of 14.8 yr after their initial evaluation, with a follow-up rate of 86%. The mean age at follow-up was 24.7 yr. We assessed the predictive value of sex and various childhood variables on the outcome of symptoms and medication use in adulthood. Although only 19% of subjects were still under a physician's supervision at the time of follow-up, 76% had respiratory symptoms, 32% used maintenance medication, and 22% used medication intermittently. The incidence of cigarette smoking was disturbingly high (33%). In adulthood, women were more likely than men to have symptoms (85 versus 72%, respectively). The childhood symptom severity and the childhood degree of bronchial responsiveness in combination with a low %FEV1 were also related to the outcome of asthma in adulthood. The high prevalence of symptoms in adults at follow-up coupled with the low rate of physician supervision and medication usage suggest that more aggressive treatment may be indicated in asthmatic children.

Adult↗
PubMed1993

Risk factors for ventilatory impairment among middle-aged and elderly men. The Normative Aging Study.

To evaluate the relationship of atopy and inflammation to the occurrence of ventilatory impairment, we studied 1,301 middle-aged and older men participating in the Normative Aging Study at the time of their 1984 to 1987 examination. Screening at entry to the study in the 1960s had excluded subjects with asthma and other chronic diseases at that time. After adjustment for smoking status and pack-years in this cross-sectional analysis, a weak inverse relationship between FEV1 and blood eosinophil count was not statistically significant, and FEV1 showed no relationship to blood eosinophil count as a percentage of total leukocytes. A weak inverse relationship between FEV1 and serum total IgE concentration was not statistically significant. Cutaneous immediate hypersensitivity to one or more common aeroallergens was not related to FEV1. A significant inverse relationship between FEV1 and blood total leukocyte count was observed in never and former smokers. FEV1 was significantly lower in subjects reporting usual phlegm production. These findings suggest that ventilatory impairment is not related to atopic status among middle-aged and older men without a history of asthma. The inverse relationship between total leukocyte count and FEV1 in this sample supports the hypothesis that nonallergic inflammation plays a role in the pathogenesis of chronic airflow obstruction in this group.

Aged↗
PubMed1993

Prediction of respiratory symptoms by peripheral blood neutrophils and eosinophils in the First National Nutrition Examination Survey (NHANES I).

To examine specific cellular markers of inflammation in peripheral blood (neutrophils and eosinophils) and their relationship to respiratory symptoms, we used data from the First National Health and Nutrition Examination Survey (NHANES I). Cross-sectional data were available on a random sample of 6,913 adults aged 30 to 74 years who had American Thoracic Society-National Heart, Lung, and Blood Institute questionnaire information on respiratory symptoms and illnesses, including asthma, chronic bronchitis, dyspnea (grade 3), chronic cough, and chronic phlegm. Information was available on age, race, smoking status, peripheral blood leukocyte count, and differential cell count. These data were analyzed using logistic regression controlling for age, race, sex, and cigarette smoking. Physician-diagnosed asthma was significantly associated only with the eosinophil count (p = 0.001). Physician-diagnosed bronchitis was significantly associated with the neutrophil count (p = 0.012) and marginally associated with the eosinophil count (p = 0.072). Chronic phlegm was also significantly associated with both the eosinophil count (p = 0.049) and the neutrophil count (p = 0.041). Grade 3 dyspnea (p = 0.049) was only significantly associated with the neutrophil count. These data suggest that both peripheral blood neutrophils and eosinophils are associated with a broad range of respiratory symptoms and that the eosinophil may play a role in nonasthmatic respiratory inflammation.

Adult↗
PubMed1993

Clinical and environmental predictors of preterm labor.

OBJECTIVE: To determine the magnitude of risk for preterm labor associated with specific clinical and environmental factors. METHODS: Using a case-control design, 266 women with preterm labor and 512 controls were interviewed and their medical records reviewed. Crude and adjusted odds ratios were calculated for each risk factor. Population-attributable risks were estimated. RESULTS: Third-trimester bleeding, twin gestation, and chorioamnionitis at presentation were strongly associated with preterm labor (odds ratios 11.2-48.3). A history of a prior preterm delivery, vaginal bleeding in the first or second trimester, maternal diethylstilbestrol exposure, uterine anomalies, and urinary tract infection during pregnancy were associated to a lesser extent (odds ratios 1.6-5.4), as were cigarette smoking and drug use (odds ratios 2.0 and 3.0). Cases who had preterm labor preceded by premature rupture of the membranes had a substantially higher risk of preterm labor if chorioamnionitis, vaginal bleeding early in pregnancy, or urinary tract infection was present. By contrast, women who had intact membranes at the onset of preterm labor carried higher risk when twin gestation, placental abruption, or uterine anomaly was present. The highest population-attributable risks for preterm labor were found in patients with a twin gestation or third-trimester bleeding. CONCLUSIONS: Programs to reduce the preterm delivery rate should consider the attributable risks for the factors they are intended to modify. The attributable risks we obtained suggest that medical strategies to reduce the impact of the clinical variables, especially multiple gestation, and educational programs to decrease smoking and drug use should reduce the preterm delivery rate.

Adult↗
PubMed1992

Obesity and body fat distribution in relation to the incidence of non-insulin-dependent diabetes mellitus. A prospective cohort study of men in the normative aging study.

The relation between the abdominal accumulation of body fat, total-body adiposity, and blood glucose level and the risk of non-insulin-dependent diabetes mellitus was evaluated prospectively among 1,972 male participants in the Department of Veterans Affairs Normative Aging Study cohort. The risk of non-insulin-dependent diabetes mellitus was assessed by means of the proportional hazards model; 226 cases of diabetes occurred among the 1,972 men (mean age at entry, 41.9 years; range, 22-80 years) over 35,496 person-years of observation. The relation of body mass index to diabetes risk was partly explained by body fat distribution; after adjusting for age, the ratio of abdominal circumference to hip breadth, and cigarette smoking, men in the top tertile for body mass index had a 1.3-fold greater risk of diabetes than did men in the lowest tertile (95% confidence interval 0.9-1.8). Moreover, after adjusting for age, body mass index, and cigarette smoking, men in the top tertile for the ratio of abdominal circumference to hip breadth had a 2.4-fold greater risk of diabetes than did men in the lowest tertile (95% confidence interval 1.7-3.7). When blood glucose was analyzed as a continuous outcome variable, the findings were consistent, i.e., a positive association with abdominal fat independent of total-body adiposity. These results confirm previous reports of a prospective relation between abdominal adiposity and the risk of diabetes and provide prospective evidence of a relation between blood glucose levels and both body fat distribution and obesity.

Abdomen↗
PubMed1992

The relationship of nasal disorders to lower respiratory tract symptoms and illness in a random sample of children.

We examined the relationship of nasal disorders, defined as frequent colds and sinus trouble, to lower respiratory tract symptoms in a random population of 718 children aged 4 to 11 years in East Boston, Massachusetts. Frequent colds were significantly associated with maternal smoking (odds ratio (OR) = 3.00; 95% confidence interval (CI) = 1.97, 4.58), and so was sinus trouble (OR = 4.73; 95% CI = 1.78, 12.51). After adjustment for maternal smoking, age and sex, frequent colds (OR = 2.88; 95% CI = 1.87, 4.42) and sinus trouble (OR = 4.95, 95% CI = 1.83, 13.39) remained significant predictors of lower respiratory tract symptoms in separate logistic regressions. If one restricted the cohort to the 513 children who also had personal smoking information and adjusted for this variable as well, the results for colds were unchanged (OR = 2.94; 95% CI = 1.78, 4.84) but the results for sinus trouble were now not statistically significant (OR = 2.30, 95% CI = 0.67, 7.94). We conclude that nasal disorders are associated with lower respiratory tract symptoms in children.

Child↗
PubMed1992

Caffeine intake and asthma symptoms.

Methylxanthines in the form of coffee and tea may be dietary factors that function as pharmacologic bronchodilators. To examine this hypothesis, we analyzed data from the Second National Health and Nutrition Examination Survey (NHANES II). NHANES II was conducted on a sample representative of the civilian noninstitutionalized US population, which included white and black adults aged 30 years or older. We examined the relationship of usual coffee and tea consumption from a medical history questionnaire to the presence of asthma and wheezing symptoms. Subjects who drank coffee on a regular basis had a 29% reduction in the odds of having current asthma symptoms (odds ratio, 0.71; 95% confidence interval, 0.55 to 0.93) when compared with non-coffee drinkers. The effect exhibited a significant dose-response relationship, with the number of cups of coffee consumed per day being inversely related to asthma prevalence. This relationship was independent of age, gender, and cigarette smoking. Tea consumption was not significantly related to asthma prevalence in this cohort.

Adult↗
PubMed1992

Relationship of catecholamine excretion to body size, obesity, and nutrient intake in middle-aged and elderly men.

Catecholamine release from sympathetic nerves and the adrenal medulla is influenced by diet under controlled research conditions. To test whether diet affects catecholamine excretion in free-living men, the urinary content of dopamine (DA), epinephrine (Epi), or norepinephrine (NE) was measured in 24-h collections provided by 572 participants of the Normative Aging Study of the Veterans Administration. Average daily intakes of energy and macronutrients were assessed by means of a semiquantitative food frequency questionnaire and sodium intake by quantitation of sodium excretion. Catecholamine excretion was also examined in relation to anthropometric variables. Because DA and Epi excretion were inversely related to age, all subsequent analyses included adjustments for age. Although DA and NE were positively related to measures of body size and fatness, Epi was negatively related to body fatness. Excretion rates of all three catecholamines were directly related to total energy intake and inversely related to energy-adjusted CHO consumption.

Adult↗
PubMed1992

Trans-fatty acid intake in relation to serum lipid concentrations in adult men.

The relation of trans-fatty acid intake to fasting serum lipid concentrations was evaluated in a cross-sectional study of 748 men aged 43-85 y. Multiple-linear-regression analysis was used to adjust for age, body mass index, waist-to-hip circumference ratio, smoking status, physical activity, alcohol intake, total energy, dietary cholesterol and linoleic acid, and previous serum cholesterol concentration. Trans-fatty acid intake was directly related to total serum (r = 0.07, P = 0.04) and low-density-lipoprotein cholesterol (LDL) (r = 0.09, P = 0.01), and inversely related to high-density-lipoprotein (HDL) cholesterol (r = 0.08, P = 0.03). Trans-fatty acid intake was positively associated with the ratios of total to HDL cholesterol (r = 0.11, P = 0.002) and LDL to HDL cholesterol (r = 0.12, P = 0.001). The estimated ratios of total to HDL cholesterol were 4.4 and 4.9 for persons at the 10th (2.1 g/d) and 90th (4.9 g/d) percentiles of trans-fatty acid intake, respectively. On the basis of results from other studies, these ratios would correspond to a 27% increase in risk of myocardial infarction.

Adult↗
PubMed1992

Single breath transfer factor for carbon monoxide in an asymptomatic population of never smokers.

BACKGROUND: Data on reference values of transfer factor variables in general populations of asymptomatic never smokers are limited. The aim of this study was to examine the relation between test variables and age, height, haemoglobin concentration and carboxyhaemoglobin concentration. METHODS: Measurements of single breath transfer factor for carbon monoxide (TLCO) were obtained for a randomly selected sample of never smokers in north western Europe who were 18-73 years old and had no respiratory symptoms or disorders. Two recordings of TLCO with a ratio of inspiratory vital capacity to forced vital capacity of greater than 0.09 were obtained by standardised techniques for 304 subjects. RESULTS: The measurement errors expressed as a percentage of the common mean value of TLCO, volume adjusted TLCO (KCO), and alveolar volume (VA) were 4.5%, 4.2%, and 2.4% respectively. Multiple linear regressions showed sex specific effects of height and age on TLCO, and, in addition, of haemoglobin and carboxyhaemoglobin concentrations on KCO. VA was associated with height but not with age. The 5th and 95th centiles for TLCO and KCO in men and women were between 78% and 82% and between 120% and 127%, respectively, of predicted values when age and height were taken into account. CONCLUSION: Reference equations and normal values for transfer test variables in a large healthy population of never smokers are described in relation to age, height, and haemoglobin concentrations. To our knowledge, this is the first report of an association between carboxyhaemoglobin concentrations and KCO in a population of never smoking men and women.

Adolescent↗
PubMed1992

Elevated soluble interleukin-2 receptors in young healthy cigarette smokers: lack of association with atopy or airways hyperresponsiveness.

To study the relationship of atopy and nonspecific airways hyperresponsiveness to circulating levels of soluble interleukin-2 receptors (sIL-2R), we measured serum sIL-2R concentrations in 40 young, healthy smokers and non-smokers. Levels of sIL-2R were significantly higher in current smokers than in nonsmokers (median sIL-2R levels 605 vs. 398 U/ml, respectively; p less than 0.05). Serum sIL-2R levels were not related to nonspecific airways hyperresponsiveness to methacholine, allergy skin test reactivity, doctor-diagnosed asthma or hay fever, or respiratory symptoms of wheeze. Among current smokers, a trend toward higher sIL-2R levels (not statistically significant) was observed among subjects reporting symptoms of phlegm production. The increase in sIL-2R levels associated with cigarette smoking was similar in magnitude to that reported for immune-mediated conditions such as collagen vascular diseases and eczema. These data confirm that cigarette smoking is an important determinant of sIL-2R level, even among young healthy subjects. This effect does not appear to be related to atopic status or bronchial responsiveness. Among cigarette smokers, sIL-2R level may be related to the presence of conditions associated with phlegm production.

Humans↗
PubMed1992

Effects of asthma on pulmonary function in children. A longitudinal population-based study.

Data from a longitudinal study of childhood factors influencing the development of chronic obstructive lung disease were used to assess the effects of asthma on lung function development in male and female children. A population-based cohort of 602 white children, initially aged 5 to 9 yr, was observed prospectively for 13 yr. Spirometry was performed and a standardized respiratory and illness questionnaire was administered by trained interviewers on a yearly basis. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and forced expiratory flow between 25 and 75% of vital capacity (FEF25-75) were used as measures of lung function. The total number of children reporting asthma over the course of the study was 67. Male asthmatic subjects (n = 42) had larger average percentage of predicted FVC than nonasthmatic males (n = 277). Female asthmatic subjects (n = 23) had a lower average percentage of predicted FEV1 than nonasthmatic females (n = 260). In a multivariate analysis of the individual lung function measures, adjusting for previous level of pulmonary function, age, height, change in height, and personal and maternal smoking, males reporting active asthma had a significantly larger FVC than males with no history of asthma. In contrast, females with active asthma had a significantly smaller FEV1 than females with no history of asthma. Both males and females with active asthma had decreased FEF25-75. From our analysis, we would predict that a female who develops asthma at age 7 would experience a 5% reduction in FEV1 by age 10 and a 7% deficit by age 15.(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗
PubMed1992

The effect of maternal smoking during pregnancy on early infant lung function.

We studied the effect of prenatal maternal cigarette smoking on the pulmonary function (PF) of 80 healthy infants tested shortly after birth (mean, 4.2 +/- 1.9 wk). Mothers' prenatal smoking was measured by: (1) questionnaire reports at each prenatal visit of the number of cigarettes smoked per day, and (2) urine cotinine concentrations (corrected for creatinine) obtained at each visit. Infant PF was assessed by partial expiratory flow-volume curves and helium-dilution measurement of FRC. Forced expiratory flow rates were significantly lower in infants born to smoking mothers, both when unadjusted and after controlling for infant size, age, sex, and passive exposure to environmental tobacco smoke (ETS) between birth and the time of PF testing. Flow at functional residual capacity (VFRC) in infants born to smoking mothers was lower than that found in infants whose mothers did not smoke during pregnancy (74.3 +/- 15.9 versus 150.4 +/- 8.9 ml/s; p = 0.0007). Differences remained significant when flow was corrected for lung size (VFRC/FRC: 0.87 +/- 0.26 versus 1.77 +/- 0.12 s-1; p = 0.013). No differences in pulmonary function were evident among infants exposed and unexposed to ETS in the home after stratifying by prenatal exposure status. We conclude that maternal smoking during pregnancy is associated with significant reductions in forced expiratory flow rates in young infants. The results suggest that maternal smoking during pregnancy may impair in utero airway development and/or alter lung elastic properties. We speculate that these effects of maternal prenatal smoking on early levels of forced expiratory flow may be an important factor predisposing infants to the occurrence of wheezing illness later in childhood.

Adult↗