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S T Weiss

Publications and source records attributed to S T Weiss.

At least 217 records · Page 12Linked to original sources
PubMed1990

Dietary factors and their relation to respiratory symptoms. The Second National Health and Nutrition Examination Survey.

Dietary factors may influence inflammatory and antioxidant activity, and hence the development of chronic respiratory symptoms. To examine this hypothesis, the authors 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 9,074 white and black adults aged 30 years or older. Dietary factors were derived from serum levels and from a 24-hour dietary recall questionnaire. The authors examined the relations of these dietary factors to the presence of currently active respiratory symptoms. The relation of serum vitamin C, dietary vitamin C intake, dietary fish intake, the ratio of dietary sodium to dietary potassium, and the ratio of serum zinc to serum copper to the respiratory symptoms of bronchitis and wheezing was assessed. Initially, nutrient-specific logistic regression analysis was performed, controlling for age, race, sex, calories, and pack-years of cigarette smoking. When multiple nutrients and total caloric intake were considered for each respiratory symptom outcome, bronchitis was negatively associated with serum vitamin C and with the serum zinc:copper ratio and was positively associated with the sodium:potassium ratio. Wheezing was negatively associated with serum vitamin C, niacin, and the serum zinc:copper ratio. Interactions between nutrients and smoking status were not significant. These data suggest that several dietary constituents may influence the occurrence of respiratory symptoms in adults, independently of cigarette smoking.

Adult↗
PubMed1990

Early childhood predictors of asthma.

To investigate potential risk factors for the development of childhood asthma, the authors undertook a longitudinal study using a cohort of 770 children aged 5-9 years from East Boston, Massachusetts, that has been under study since 1975. The disease outcome considered was age at first onset of asthma, as determined by parental or self-reporting of a physician's diagnosis. Potential risk factors were evaluated specifically in relation to their presence antecedent to a diagnosis of asthma. Standardized questionnaires were used to obtain childhood illness histories, environmental exposures, and the asthmatic and atopic statuses of first-degree relatives. Ninety-one cases of asthma were identified from 1975 to 1988 (57 males and 34 females). Significant sex-adjusted relative risk estimates were seen for antecedent pneumonia, bronchitis, hay fever, sinusitis, parental asthma, and parental atopy. Neither bronchiolitis, eczema, croup, personal cigarette smoking, maternal smoking, paternal smoking, nor delivery complications bore an apparent relation to the development of asthma. A history of parental asthma or parental atopy did not significantly alter the sex-adjusted relative risk estimates for pneumonia, bronchitis, hay fever, or sinusitis. These results support the hypothesis that asthma is a multifactor disease whose expression is dependent on both familial and environmental influences.

Asthma↗
PubMed1990

The relationship of nonspecific airway responsiveness and atopy to the rate of decline of lung function. The Normative Aging Study.

Nonspecific airway hyperresponsiveness and atopy have been postulated to be risk factors that predispose individuals to the development of chronic obstructive pulmonary disease. The purpose of the present study was to examine the relationship of methacholine airway responsiveness and markers of atopy to rate of decline in lung function among 790 men, age 40 to 79 yr, followed in the Normative Aging Study. Airway responsiveness was assessed at the end of follow-up, which ranged from 14 to 24 yr. Multiple linear regression analysis indicated that greater methacholine airway responsiveness was associated with more rapid annual FEV1 decline. Stratified analysis suggested that this association was stronger among skin test-negative, current smokers. No significant relationship was found between serum IgE level and annual FEV1 decline. A weak but statistically significant correlation between eosinophil count and mean annual FEV1 decline was noted among skin test-negative individuals (r = -0.08; p = 0.03). Results from the present study do not show a clear association between atopy and decline in FEV1. These data, however, do indicate an independent association between heightened methacholine responsiveness on decline in FEV1 in adult males.

Adult↗
PubMed1990

Pulmonary function measures in healthy infants. Variability and size correction.

We conducted 151 tests of pulmonary function (PF) on 72 healthy infants younger than 2 yr of age using partial expiratory flow volume (PEFV) maneuvers and helium dilution determination of FRC. After tests were grouped into four strata based on postconception (PC) age, variability and sex differences in level of PF were examined. No significant sex differences were found for any PF measure in any age stratum, even when somatic size was controlled by length correction. Force expiratory flow measures, however, tended to be greater in girls than in boys in the youngest infants. Flow measures demonstrated greater between-subject variability than did volumes, and variability was greatest in the youngest infants. Within-subject variability also was more pronounced for flow measures, particularly in infants younger than 50 PC wk of age. Across the age range of infants studied, all PF measures were related linearly to somatic size as measured by either length, weight, or chest circumference. Length offered the best individual size correction of the three size parameters studied. Linear regression of PF parameters versus length demonstrated FRC to increase at 5.39 ml/cm over this age range, whereas flow at FRC increased by 9.67 ml/s/cm. We conclude that the variability of infant PF measures is greatest in early infancy, that measures of forced expiratory flow are more variable than volume measures, and that sex differences in infant PF do not appear significant. Length is related linearly to PF measures and offers reasonable size correction for healthy infants younger than 18 months of age.

Age Factors↗
PubMed1990

Predictors of asthma and persistent wheeze in a national sample of children in the United States. Association with social class, perinatal events, and race.

This study analyzes data from the Second National Health and Nutritional Examination Survey to determine whether black children are more likely to have asthma or wheeze, even after adjusting for environmental and socioeconomic exposures. For children 6 months to 11 yr of age, the unadjusted prevalence for asthma was 3.0% among white children and 7.2% among blacks; prevalence of frequent wheeze was 6.2% among whites and 9.3% among blacks. In a logistic regression model including race, age, and sex, the relative odds (RO) of asthma for black children as compared to white children were 2.5 (95% confidence interval [Cl], 1.9 to 3.4). Other predictors of asthma in a stepwise logistic regression included age, sex (boys versus girls, RO = 1.4), younger maternal age (2 standard deviation [SD] drop in age, RO = 1.4), residence in the central city (RO = 1.6), and family income (RO for the lowest versus highest tertile, RO = 1.7). After adjusting for these risk factors, age and sex, black children still had a 1.7 RO (95% Cl, 1.2 to 2.1) of having asthma. Frequent wheeze was associated with race (black versus white, RO = 1.6), sex (boys versus girls, RO = 1.3), birth weight (2 SD deficit in birth weight, RO = 1.4), and triceps skinfold thickness (increase in odds of asthma for 2 SD increase in skinfold, RO = 1.6). The significant effect of maternal age and birth weight after adjusting for other confounding variables suggests that the in utero environment may be an important determinant of asthma.(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗
PubMed1990

The relationship of body fat distribution to blood pressure in normotensive men: the normative aging study.

Body fat distribution may be a more specific marker than obesity for risk of cardiovascular disease and diabetes. The relationship between body fat distribution and sitting systolic and diastolic blood pressure was examined in a cross-sectional analysis of 1936 normotensive men aged 21 to 80 years. In this analysis body fat distribution was represented by the ratio of abdomen circumference to hip breadth (denoted as WHbR). Pearson product-moment correlations adjusted for age revealed a positive correlation between WHbR and both systolic and diastolic blood pressure (r = 0.13 and r = 0.14, respectively). In a multiple linear regression model controlling for age, smoking status and body mass index (BMI), WHbR was associated with systolic blood pressure [regression coefficient (standard error) = 3.58 (1.8), P = 0.048)], but had much less of an association with diastolic blood pressure [regression coefficient (standard error) = 1.90 (1.3), P = 0.141]. Further adjustment for alcohol intake decreased the association between WHbR and systolic blood pressure [regression coefficient (standard error) = 2.90 (1.81), P = 0.110]. Body fat distribution, as represented by WHbR was associated with level of systolic blood pressure independently of overall level of obesity (BMI) in normotensive men; adjustment for alcohol intake attenuated the relationship. These data suggest that dietary factors, notably alcohol intake, may influence the effect of body fat distribution on blood pressure.

Adipose Tissue↗
PubMed1989

Genotypic and phenotypic similarities in pulmonary function among family members of adult monozygotic and dizygotic twins.

Population studies have demonstrated that obstructive airways disease aggregates within families. The authors used a twin family model of analysis to estimate the genetic and environmental influences on pulmonary function. A total of 1,635 members of 414 families of adult twins (252 monozygotic, 162 dizygotic) enrolled in the Greater Boston Twin Registry were studied between 1981 and 1982. Correlations in levels of forced expiratory volume in one second (FEV1) and forced vital capacity (FVC), adjusted for age, sex, height, and current smoking status, were compared among 16 groups of relatives sharing various degrees of genetic relatedness. A direct relation between shared genotype and the magnitude of the familial correlations for pulmonary function was observed. For FEV1, the correlations were 0.71 for monozygotic twins (100% shared genotype), 0.16 to 0.29 for relatives with 50% shared genotype, 0.09 to 0.27 for relatives with 25% shared genotype, 0.06 for cousins with 12.5% shared genotype, and -0.14 to 0.14 for unrelated family members. Correlations for FVC were similar. Stratification of the analysis by concordance or discordance for passive tobacco smoke exposure or for frequency with which families visited one another did not systematically alter these relations. These data suggest that phenotypic similarities in pulmonary function relate directly to genetic similarities, and are consistent with a multifactorial mode of inheritance.

Adolescent↗
PubMed1989

Comparison of questionnaire and diary methods in acute childhood respiratory illness surveillance.

We compared two prospective survey methods, an interviewer-administered questionnaire and a daily diary, used concurrently to record acute respiratory illness experience over a 2-yr period in 422 children 5 to 11 yr of age from East Boston, Massachusetts. Respondents contributed more months of data with the questionnaire than with the diary method. Respiratory symptom and illness rates, as determined for the first year by each of the methods, were compared for 277 children who had less than 4 months of missing data. Respondents from families with more children tended to report a lower total respiratory illness rate by the diary than by the questionnaire method (p = 0.006). Although upper respiratory illness rates did not differ by method, lower respiratory illnesses were reported more frequently (p = 0.0001) by questionnaire than by diary. In the group of 49 children who were identified as having had greater than one lower respiratory illness, 25% of the illnesses reported as having been lower respiratory by questionnaire were reported as having been another form of respiratory illness by diary. For this group the ratio of 3:1 of boys to girls for the diary as compared with 1.5:1 for the questionnaire suggests the presence of reporting bias and no comparability of methods. Standardization of an acute respiratory illness questionnaire would provide greater opportunity than use of diaries for synthesis of prospective data from different epidemiologic studies.

Acute Disease↗
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

The relationship between longitudinal change in pulmonary function and nonspecific airway responsiveness in children and young adults.

The relationship between airway hyperresponsiveness and longitudinal change in lung function was assessed in a population-based sample of 184 children and young adults observed over a maximum span of 12 yr. Pulmonary function was assessed annually with spirometry, and health and household information was obtained with standardized questionnaires. Nonspecific airway responsiveness to eucapneic hyperventilation with subfreezing air was measured on at least two occasions between the sixth and twelfth annual surveys. At any given survey, a significant bronchoconstrictor response was defined as [( prechallenge FEV1-postchallenge FEV1]/pre-FEV1) greater than or equal to 0.13, a value that identified 10% of the population. Subjects were classified as "never", "always", or "inconsistent" responders according to the consistency of responsiveness determined in different surveys. Subjects were classified further as "labile" if their maximal survey-to-survey difference in delta FEV1/FEV1 was greater than or equal to 0.18, and as "nonlabile" otherwise. A Markov-type autoregressive model that adjusts for previous pulmonary function level, sex, growth variables, and smoking exposures was used to model growth of FEV1, FEF25-75, and FVC. Overall, 135 (73%) of subjects never responded to the cold air challenge, six (3%) always responded, and 43 (24%) responded on one but not all occasions. Levels and rates of increase in level of FEF25-75 were significantly lower in the inconsistent and always responders. In contrast, levels of FVC were greatest and increased most in the always responders. In labile subjects, both FEF25-75 and FEV1 growth rates were reduced. These effects persisted when asthmatics were excluded from the analyses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

The role of allergy and nonspecific airway hyperresponsiveness in the pathogenesis of chronic obstructive pulmonary disease.

Although the information that has been reviewed leaves many questions unanswered, some conclusions can be drawn from available data. (1) Smoking appears to increase the risk of sensitization to certain inhaled antigens encountered in the workplace; however, there is no definite evidence that smoking increases the frequency or intensity of allergy to common aeroallergens in the general population. On average, smokers have higher serum total IgE concentrations and blood eosinophil counts than do nonsmokers, but the mechanisms underlying these alterations are not clear. Analysis of these relationships is complicated by observations suggesting that atopic persons are less likely to become and to remain regular cigarette smokers. (2) Long-term cigarette smoking may be associated with increased nonspecific airway responsiveness, although the magnitude of this effect is relatively small when one adjusts for prechallenge level of pulmonary function. This effect of smoking may be more pronounced in atopic persons. (3) Atopy, as assessed by skin testing and serum IgE concentrations, is associated with asthma, nonspecific airway hyperresponsiveness, and reduced pulmonary function level in population data. However, there is no clear evidence that atopy is a risk factor for irreversible airflow obstruction in persons without asthma. Population data do not indicate how much of the reduction in pulmonary function associated with atopy and asthma is potentially reversible. (4) Blood eosinophil count appears inversely related to the level of pulmonary function and directly related to the rate of decline of pulmonary function among nonsmokers. Reports vary concerning whether the relationship of eosinophil count to level of pulmonary function remains after excluding subjects with diagnosed asthma. This relationship may be determined largely by a clinically distinguishable subset of nonsmokers with "asthmatic bronchitis." Presumably, these observations reflect an adverse impact of eosinophilic inflammation in the airways or lung parenchyma. It is not clear whether this represents an allergic response because skin-test reactivity to common aeroallergens and serum total IgE concentration do not show similar relationships to reduced level and rapid decline of pulmonary function. (5) Among smokers, nonspecific airway hyperresponsiveness appears to be associated with an accelerated longitudinal decline of pulmonary function, although most studies indicating this association are limited by either a retrospective design or lack of adjustment for prechallenge level of pulmonary function.(ABSTRACT TRUNCATED AT 400 WORDS)

Bronchi↗
PubMed1989

The distribution of bronchial responsiveness to histamine in symptomatic and in asymptomatic subjects. A population-based analysis of various indices of responsiveness.

The distribution of bronchial responsiveness (BR) and the place of symptomatic subjects in this distribution was investigated in a random population sample of 339 subjects who participated in the 1984 survey of the Vlagtwedde/Vlaardingen Study. BR was assessed by a histamine provocation test. The following indices of BR were used: (1) a histamine threshold both at 10 and at 20% decreases in FEV1 (PC10 and PC20); (2) the concentration causing a 10 or a 20% decrease estimated by linear interpolation (IPC10 and IPC20), and by linear regression of all data points (PD10 and PD20); (3) the slope of the linear regression line through all data points (SAP) and the slope of the line through the origin and the last data point (SOL). Disease was defined as the self-reported presence of respiratory symptoms from a respiratory symptom questionnaire. Bronchial challenge was considered as a test to predict symptom prevalence. Receiver-operator characteristic curves were applied to define optimal cutoff points for each of the indices used to define a positive and a negative test. For each index, sensitivity, specificity, predictive value of a positive and negative test, and efficiency rate of the test were calculated. The overall distribution of BR in this population appeared to be log normal for the different continuous indices. Subjects with symptoms were on the more responsive tail of the distribution. After adjusting for age, sex, smoking habit, and level of pulmonary function, the mean log-transformed values of PD10, PD20, SAP, and SOL for the various symptom groups differed significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Acute lower respiratory illness in childhood as a predictor of lung function and chronic respiratory symptoms.

This study investigated the relationship of acute lower respiratory illness (LRI) to level and change in level of forced expiratory volumes in a cohort of 801 children, followed longitudinally for a maximum of 13 yr. The co-occurrence of respiratory illness before 2 yr of age and two or more LRI during a single surveillance year was associated with a 20.3% lower mean cross-sectional level of FEF25-75, and with reduced longitudinal change in level of FEF25-75. The effect of LRI on lung function was uniformly stronger for boys than for girls. Of the children with illness before 2 yr of age and two or more LRI, six of 14 were male asthmatics with mean levels of FEF25-75 that were lower than those of other asthmatic children. Pneumonia and/or hospitalization for respiratory illness prior to the onset of study were associated with lower cross-sectional levels of forced expiratory volumes at entry to the study, even when asthmatics/persistent wheezers were eliminated from the analysis (6.1% lower level of FEV1 for a nonasthmatic boy with previous hospitalization versus a nonasthmatic boy without hospitalization). In the longitudinal analysis, pneumonia and/or hospitalization were associated with slower increase in level of forced expiratory volumes, even after adjusting for "ever diagnosis of asthma/current any wheeze" (starting at the same leve, after eight years a boy with hospitalization would develop a 5.0% lower FEV1 than a boy without hospitalization). Acute LRI also was evaluated as a predictor of chronic respiratory symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1989

Smoking, atopy, and methacholine airway responsiveness among middle-aged and elderly men. The Normative Aging Study.

The interrelationships between smoking history, objective markers of allergy and inflammation, and methacholine responsiveness were examined among 778 middle-aged and elderly men (age range 41 to 86 yr). Methacholine responsiveness was analyzed using dose-response slope to describe each subject's responsiveness. Current smokers were observed to have significantly greater total serum IgE concentration ([IgE]), blood total leukocyte count, and blood eosinophil count than nonsmokers. Current smokers with at least one positive skin test reaction to common aeroallergens displayed significantly greater methacholine dose-response slope than smokers with negative skin test results (p less than 0.01). Among nonsmokers, skin test positivity was associated with slightly but not significantly greater methacholine responsiveness. Among subjects with negative skin test results, smoking was not associated with greater methacholine responsiveness. Blood eosinophil count and serum total [IgE] displayed weak but statistically significant direct relationships to methacholine dose-response slope (p less than 0.01), and these relationships were not significantly modified by smoking status. In a multivariate model, the cigarette smoking/skin test positivity interaction, total serum [IgE], and blood eosinophil count displayed significant, independent relationships to methacholine dose-response slope, although only a small portion of the variance of dose-response slope was accounted for by these covariates. These data suggest that smoking and atopy may act synergistically to increase the degree of nonspecific airway responsiveness displayed by middle-aged and elderly individuals. Allergic airway inflammation, as reflected by total serum [IgE] and blood eosinophil count, may also influence nonspecific airway responsiveness in this age group.

Adult↗
PubMed1988

Smoothing methods for epidemiologic analysis.

The development of techniques for fitting non-parametric smooth curves has resulted in less restrictive regression models. We discuss the ideas underlying such smoothing algorithms, develop their application to epidemiologic studies and address specific issues, such as coping with correlated errors. An example illustrates a particular smoothing approach, as applied to pulmonary function data. The method provides new insight into the effect of smoking on pulmonary function. The discussion offers some qualitative comparisons between smoothing methods and conventional linear models.

Adult↗
PubMed1988

Forced vital capacity and the risk of hypertension. The Normative Aging Study.

This report describes the development of hypertension among 1,270 males (aged 23-80 years at the time of entry into the study) observed prospectively for 10 years who had a baseline blood pressure of less than 140/90 mmHg and who underwent baseline spirometry. Subjects were participants in the Normative Aging Study, a longitudinal study on aging initiated in 1961 at the Veterans Administration Outpatient Clinic in Boston, Massachusetts. Blood pressures were taken at five- and 10-year follow-up examinations. The age-adjusted incidence of hypertension during the follow-up period was found to be inversely related to forced vital capacity. Multiple logistic regression was employed to assess the relation of forced vital capacity to the subsequent development of hypertension after controlling for baseline levels of age, weight, cigarettes smoked per day, and systolic and diastolic blood pressures. Forced vital capacity was a statistically significant and negative predictor, indicating that lower values of forced vital capacity were associated with the subsequent development of hypertension. This was consistently found in several logistic regression analyses with a standardized odds ratio associated with forced vital capacity of approximately 0.7. Although the physiologic mechanism for this association is unknown, these findings may have importance in identifying subjects at risk and may also provide insight into disease pathogenesis.

Adult↗