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Biomedical subjects

S T Weiss

Publications and source records attributed to S T Weiss.

At least 145 records · Page 8Linked to original sources
PubMed1995

Racial differences in serum immunoglobulin levels: relationship to cigarette smoking, T-cell subsets, and soluble interleukin-2 receptors.

To investigate the influence of race, cigarette smoking, and immunologic parameters on serum immunoglobulins, we analyzed serum IgG, IgA, and IgM levels in 455 healthy adults. The study population ranged in age from 20 to 69 years, including 282 whites and 173 blacks, 181 never-smokers, 93 ex-smokers, and 181 current smokers. Race and smoking were independently associated with alterations in serum IgG levels. Blacks had significantly higher IgG levels than whites (1,587 vs. 1,209 mg/dl; P < 0.001), and never smokers had significantly higher levels than current smokers (1,426 vs. 1,287 vs. mg/dl; P < 0.001). IgA and IgM levels were unrelated to race or smoking. Serum IgG was also found to be directly related to the proportion of HLA-DR+ cells and the level of soluble interleukin-2 receptors (sIL-2R) and inversely related to the proportion of CD4+ cells. Investigation of this racial heterogeneity may provide insights into the pathogenesis of immunologic diseases that exhibit unexplained racial variation.

Adult↗
PubMed1995

The relationship between heart rate variability and measures of body habitus.

There is a well-recognized relationship between autonomic nervous system function and body habitus although few studies have addressed the role of the parasympathetic nervous system. A decrease in parasympathetic nervous-system-mediated heart rate variability in obesity may in part explain the mortality and morbidity that are associated with the obese state. We used multiple linear regression techniques to explore the relationship between measures of heart rate variability and anthropometric indices in 597 male participants in the Normative Aging Study. After adjustment for age and log10 heart rate, weight and body mass index were significant predictors of both the expiratory to inspiratory ratio (E/I ratio) and the difference between maximum and minimum heart rate (HRMax-Min). The abdomen-to-hip ratio and percentage body fat were not significant predictors of measures of heart rate variability. A one standard deviation change in the anthropometric index (weight, body mass index) resulted in a decrease in the E/I ratio of 0.010-0.014 and a decrease in the HRMax-Min of 0.486-0.715 beats/min. A change in the anthropometric index across the distribution (5-95 percentile) resulted in a decrease in the E/I ratio of 0.032-0.037 and a decrease in the HRMax-Min of 1.56-2.39 beats/min. These results indicate that heart rate variability and overall body size are correlated. This association could in part explain the mortality and morbidity that is associated with the obese state.

Adipose Tissue↗
PubMed1995

Airway hyperresponsiveness to histamine associated with accelerated decline in FEV1.

An increased level of airway responsiveness has been proposed as a risk factor associated with the onset and prognosis of chronic airway obstruction. To determine this, longitudinal studies are necessary, with measurement of both the level of airway responsiveness and of additional risk factors, such as cigarette smoking, made before measurement of pulmonary function decline. The association of airways responsiveness with decline in FEV1 has been prospectively studied in a random sample of the Dutch population. Longitudinal data from 921 males, providing 2,376 paired observations, and 698 females, providing 1,682 paired observations, were used for analysis. Differences between responders and nonresponders (PC10 < or = 16 mg/ml of histamine) were estimated from linear regression analyses stratified by gender and smoking status, with adjustment for age, residential area, the presence of respiratory symptoms, indicators for each interval, and residuals of FEV1 at the beginning of the interval. Responders had a greater mean yearly decline in FEV1, and the differences between responders and nonresponders were similar for all gender and smoking subgroups. In an overall regression model, subjects with airway hyperresponsiveness had a significantly steeper decline in FEV1, independent of the other variables (males: beta = -12.5 ml/yr, SEM = 3.22, p < 0.001; females: beta = -11.50 ml/yr, SEM = 2.98, p < 0.001). The current analyses conclusively demonstrated that increased airway responsiveness is an independent risk factor for an accelerated decline in FEV1 and, hence, for the development of chronic obstructive lung disease. The mechanisms by which increased airway responsiveness leads to an accelerated decline in FEV, are imperfectly understood and require further study.

Adolescent↗
PubMed1995

Dietary antioxidant vitamin intake and lung function in the general population.

We have investigated the relation between lung function and dietary intake of the antioxidant vitamins C and E in the general population in a cross-sectional survey of a random sample of adults from the electoral register of an administrative area of Nottingham. In 2,633 subjects 18 to 70 yr of age, we measured FEV1 and FVC, allergen skin sensitivity to grass pollen, cat fur, and Dermatophagoides pteronyssinus, pack-years smoking exposure by personal recall, and usual dietary intake of vitamins C and E by semiquantitative food frequency questionnaire. After adjustment for the effects of age, sex, height, mean allergen skin wheal diameter, and pack-years smoking history, both FEV1 and FVC were significantly and independently related to mean daily intake of vitamin C, such that a standard deviation (40 mg/d) higher vitamin C intake was associated with a 25.0 (95% CI, 5.2 to 44.8; p = 0.01) ml higher FEV1 and a 23.3 (0.94 to 45.7, p = 0.04) ml higher FVC. There was also an association between vitamin E intake and lung function, such that a standard deviation (2.2 mg) higher intake of vitamin E was associated with a 20.1 (1.3 to 40.4, p = 0.04) ml higher FEV1 and a 23.1 (1.0 to 45, p = 0.04) ml higher FVC. However, vitamin C and vitamin E intakes were significantly correlated (r = 0.29, p < 0.001), and after allowing for the effects of vitamin C there was no additional independent effect of vitamin E on either FEV1 or FVC.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

A prospective study of diet and adult-onset asthma.

A role for diet in the pathophysiology of asthma may be mediated by altered immune or antioxidant activity with consequent effects on airway inflammation. We evaluated associations between several dietary factors assessed by a semiquantitative food frequency questionnaire, and incidence of asthma over a 10-yr period in 77,866 women 34 to 68 yr of age. Women in the highest quintile of vitamin E intake from diet, but not from supplements, had a risk of 0.53 (95% confidence interval [CI] = 0.33 to 0.86) compared with women in the lowest quintile. This relationship, however, was attenuated when the contribution from nuts, a major source of vitamin E in these data and a possible allergen, was removed (relative risk = 0.74 [0.50 to 1.10], p for trend = 0.007). Positive associations were found for vitamins C and E from supplements, but appeared to be explained by women at high risk of asthma initiating use of vitamin supplements prior to diagnosis. A nonsignificant inverse association with carotene intake was noted, but no clear relations with asthma were demonstrated for intake of linoleic acid or omega-3 fatty acids. These data suggest that antioxidant supplementation and intake of various fats during adulthood are not important determinants of asthma, although vitamin E from diet may have a modest protective effect.

Adult↗
PubMed1995

A prospective longitudinal study of methacholine airway responsiveness as a predictor of pulmonary-function decline: the Normative Aging Study.

It has been hypothesized that nonspecific airway hyperresponsiveness is a risk factor for accelerated pulmonary-function decline during aging and the development of chronic airflow obstruction. We tested this hypothesis in a prospective, longitudinal study of 912 middle-aged and older men (median age, 60 yr; range, 41 to 86 yr) participating in the Normative Aging Study (NAS). Subjects underwent methacholine challenge testing and spirometry at the time of a regularly scheduled NAS examination, and follow-up spirometry was performed after a median interval of 3.3 yr. Allergy skin testing with a panel of four aeroallergens (mixed grasses, mixed trees, ragweed, and house dust) was also performed at the initial examination. Methacholine responsiveness was expressed as the dose-response slope (DRS) (i.e., the slope of a line connecting the origin with the last point of the methacholine dose-response plot) in units of percent decline FEV1/mumol methacholine. The relationship of the methacholine DRS to the subsequent rate of annual decline in lung function (FEV1, FVC, and FEV1/FVC) was examined using multiple linear-regression models with the rates of pulmonary-function decline as the outcome variables. After adjusting for age, height, smoking status, and initial level of lung function, the log10 DRS was a significant predictor of the rate of decline of FEV1 (regression coefficient beta = 12.8, p = 0.03) and FEV1/FVC x 100 (beta = 0.506, p = 0.0001), and a borderline significant predictor of FVC (beta = 15.3, p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1995

Relationship of skin test reactivity to decrements in pulmonary function in children with asthma or frequent wheezing.

We examined the relationship between skin test reactivity and level of FEV1 in a stratified random sample of U.S. children 6 to 12 yr of age with asthma or frequent wheezing, studied as part of the Second National Health and Nutrition Survey (NHANES II). Subjects were considered symptomatic if they reported asthma or wheezing. Spirometry was performed according to ATS standards. Skin test reactivity to Alternaria, Bermuda grass, cat, dog, house dust, mixed long and short ragweed, oak, and rye grass allergens was determined. House dust mite (-17% FEV1; 95% CI, -9 to -25), dog (-28% FEV1; 95% CI, -11 to -42), and oak (-26% FEV1, 95% CI, -16 to -35) were associated with the greatest decrements in FEV1. In general, indoor allergens (-13% FEV1; 95% CI, -6 to -20) were associated with greater effects than outdoor allergens (-5% FEV1; 95% CI, -2 to -13). The association of indoor allergens with reduced FEV1 was greater in girls (-16% FEV1; 95% CI, -5 to -25) than in boys (-8% FEV1; 95% CI, -3 to -13). Sensitization to indoor allergens among symptomatic children 6 to 12 yr of age was associated with decrements in level of FEV1.

Allergens↗
PubMed1995

Chronic respiratory symptoms and airway responsiveness to methacholine are associated with eosinophilia in older men: the Normative Aging Study.

Identification of subsets of patients with chronic obstructive lung disease (COLD) in order to determine disease outcomes and, possibly, the effects of treatment is an area of clinical interest. At present, it remains unclear which patients with COLD are most likely to benefit from anti-inflammatory therapy. We investigated this question in a community-dwelling sample of men. In this study, the relationship of chronic respiratory symptoms, airway responsiveness to methacholine, and skin test reactivity to peripheral-blood eosinophil and neutrophil counts was examined among 894 male participants in the Normative Aging Study (mean age 60 yrs; range 41-90 yrs). The symptoms considered were asthma, persistent wheeze, dyspnoea, chronic cough and phlegm. Responsiveness to methacholine was defined as a provocative dose producing a 20% fall in forced expiratory volume in one second (PD20FEV1) of < or = 8.6 mumol, a positive skin test as a wheal diameter of > or = 5 mm after subtraction of the diameter of any wheal reaction to a glycerin control, and eosinophilia as an eosinophil count of > or = 275 cells.mm-3 in peripheral blood. Chronic symptoms (odds ratio (OR) 2.0; 95% confidence interval (CI) 1.4-2.7), airway responsiveness (OR 1.7; CI 1.1-2.7), and the combination of symptoms and airway responsiveness (OR 3.4; CI 2.0-5.6) were positively and significantly related to peripheral-blood eosinophil counts. These relationships remained significant after adjustment for the effects of age and smoking, and after exclusion of asthmatic subjects. Symptoms and airway responsiveness combined were not significantly related to neutrophil counts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Comparing FEV1 in adults in two community-based studies.

Data collected in two large-scale longitudinal respiratory studies were analyzed to estimate age-related changes in FEV1 and to determine the between-study differences in change in FEV1 among nonsmoking participants. Two adult cohorts in the Netherlands were followed up for 21 years at 3-year intervals and a cohort of adults in 6 cities in the eastern United States was followed up for 6 years. The age distributions and follow-up rate differed for the two studies. The mean rates of decline in FEV1 for 50-year old male and female never smokers were 27.9 +/- 2.8 mL/yr and 22.1 +/- 0.9 mL/yr, respectively, in the Netherlands cohort. The estimates for men and women in the Six Cities cohort were 33% and 32% greater, respectively, than those for the Netherlands cohort (p < 0.01). The estimated rate of decline in FEV1 associated with each 1-year increase in age was 0.50 +/- 0.12 mL/yr for men and 0.61 +/- 0.08 mL/yr for women in the Netherlands cohort. This estimate was comparable for the Six Cities women and the Netherlands women but significantly different for the two cohorts of men. Inclusion of survey (period) effect in the regression model had only a trivial influence on accelerated rate of decline in FEV1 and did not alter the more rapid acceleration of decline in FEV1 among the Six Cities men. The present study also showed that use of a "prediction equation" for age adjustment to compare across population samples may produce a biased conclusion if the estimated rate of decline in FEV1 associated with age is different and the age distributions are different for the two populations. In addition, height adjustment for FEV1 was found to have a negligible influence on the longitudinal estimates of FEV1 decline in both study samples. In conclusion, substantial between study variation in decline in FEV1 occurs despite use of similar data analysis techniques. Differences in the initial age distributions and loss to follow-up appeared to be important factors in this analysis.

Adult↗
PubMed1995

Quality of care for preschool children with asthma: the role of social factors and practice setting.

OBJECTIVE: To determine whether patient race or source of payment is associated with differences in the quality of inpatient and outpatient treatment for young children with asthma. DESIGN: Structured medical record review. SETTING: Tertiary care pediatric hospital. PATIENTS: We studied 354 patients aged 1 to 6 years discharged with asthma between October 1, 1989 and September 30, 1990. MEASURES: We developed indicators of the quality of asthma care provided before and during hospitalization and planned after discharge. Outpatient indicators were the use of inhaled beta-agonists and the use of preventive anti-inflammatory medications (inhaled steroids or cromolyn sodium) before admission. In-hospital indicators were the intensity of inhaled beta-agonist therapy in the emergency department and length of stay. Planning for post-hospital care was assessed by the prescription of a nebulizer for home use. We examined associations between these indicators and patient race and source of payment, and explored the influence of primary-care practice type on these associations. RESULTS: After adjustment for potential confounders, we found that Hispanic patients were less likely than white patients to have taken inhaled beta-agonists before admission. Both black and Hispanic patients were less likely than white patients to have taken anti-inflammatory medications. When we adjusted for the patients' primary-care practice type, the effect of patient race did not persist for these indicators of outpatient care. We found no differences by patient race in emergency department care or length of hospital stay. However, black and Hispanic patients were much less likely to be prescribed a nebulizer for home use upon discharge. After adjustment for confounders, there were no differences in the quality of asthma care by source of payment. CONCLUSIONS: We found that young children of racial minorities admitted for an asthma exacerbation were less likely to have received maximally effective preventive therapy. We also identified marked differences in the quality of care planned after hospital discharge for black and Hispanic patients, compared with white patients. Particularly in an era of health reform, attention should focus on barriers to high-quality care for underserved children, who are already at high risk for asthma-related morbidity.

Adrenergic beta-Agonists↗
PubMed1994

Low-level lead exposure and renal function in the Normative Aging Study.

Occupational and environmental lead exposure has been associated with significant impairment in renal function. The authors studied the cross-sectional relation between creatinine clearance and blood lead concentration in a population of 744 men participating in the Normative Aging Study of the Department of Veterans Affairs between July 1988 and April 1991. These men, aged 43-90 years, were recruited from communities in the Greater Boston, Massachusetts, area and were selected without regard to lead exposure. The mean values for blood lead concentration and creatinine clearance rate were 8.1 micrograms/dl (standard deviation, 3.9 micrograms/dl) and 88.2 ml/minute (standard deviation, 22.0 ml/minute), respectively. Independent relations of creatinine clearance to blood lead were assessed by multivariate linear regression analysis, with adjustment for various potential confounders. In multivariate linear regression models, the rate of creatinine clearance was significantly and negatively associated with increasing levels of blood lead, even after adjustment for age, body mass index, and use of diuretic and analgesic medications (the beta-coefficient for ln blood lead measured in microgram[microgram/dl]-1 was -0.030; standard error = 0.014, p = 0.037). A rise in ln blood lead of 10.0 micrograms/dl was associated with a decrease in the ln creatinine clearance rate of 10.4 ml/minute. These results support the hypothesis that exposure to low-level environmental lead correlates with a significant decrement in renal function.

Adult↗
PubMed1994

The relationship of epinephrine excretion to serum lipid levels: the Normative Aging Study.

Catecholamines are known to stimulate lipolysis of triglyceride stores in adipose tissue. However, the relationship of sympathoadrenal activity to serum lipid and lipoprotein concentrations remains uncertain. Since obesity, particularly the centripetal form, has recently been shown to be associated with increased urinary excretion of norepinephrine and decreased excretion of epinephrine, the possibility that the sympathoadrenal system is involved in the lipid abnormalities associated with the centripetal form of obesity was investigated. The relationship between 24-hour urinary catecholamine excretion and serum lipid and lipoprotein levels was examined among 615 male participants of the Normative Aging Study. Epinephrine excretion was positively correlated with the high-density lipoprotein cholesterol (HDL-C) level and the ratio of HDL-C to low-density lipoprotein cholesterol ([LDL-C] r = .15, P = .0002, and r = .11, P = .007, respectively) and inversely correlated with the triglyceride level (r = -.14, P = .0005). These relationships remained significant after adjusting for the effects of age, smoking, alcohol intake, adiposity, and insulin level. Epinephrine excretion was not significantly related to levels of total cholesterol or LDL-C. Norepinephrine and dopamine excretion were not significantly related to any lipid variable. These data suggest that (1) epinephrine plays an important role in regulating lipid and lipoprotein metabolism in humans, and (2) decreased adrenal medullary activity may contribute to the dyslipidemia (increased triglycerides and decreased HDL-C) commonly observed among the obese. The sympathoadrenal system therefore, along with hyperinsulinemia, may contribute to the increased cardiovascular risk associated with the insulin resistance syndrome.

Adult↗
PubMed1994

Host factors and environmental determinants associated with skin test reactivity and eosinophilia in a community-based population study.

We examined the relationship of host factors (age, gender) and environmental determinants (smoking status, area of residence) to indicators of allergy (skin test reactivity and eosinophil count) in a random population sample in the Netherlands. Positive skin test reactivity was associated with age (decreasing with increasing age), with male gender (versus female gender), and with urban residence (versus rural residence). Positive skin test reactivity was not associated with smoking. Elevated eosinophil counts were associated with male gender (versus female gender), with urban residence (versus rural residence), and with current smoking (versus never smoking). Elevated eosinophil counts were not clearly associated with age (if adjusted for the age-related effects of skin test reactivity). Additionally, this study specifically demonstrates that skin test reactivity increases with increasing eosinophil count and vice versa, indicating that the two traits are interrelated. Furthermore, this interrelationship was demonstrated to be age-dependent (decreasing with increasing age).

Adolescent↗
PubMed1994

Cigarette smoking and peripheral blood leukocyte differentials.

Cigarette smoking increases the total peripheral blood leukocyte count but its effect on the differential cell count in peripheral blood is largely unexplored. We studied 6138 subjects between the ages of 30 and 74 years who were seen as part of the First National Health and Nutrition Examination Survey in 1971 to 1974 to assess the relationship of current smoking status, number of cigarettes smoked per day, pack-years of smoking, and years since quitting, to the absolute and percent count of neutrophils, eosinophils, lymphocytes, and monocytes in peripheral blood. The relationship of cigarette smoking to the differential cell counts was adjusted for age, race, sex, and obesity by multiple regression. Pack-years smoked, years since quitting, and current number of cigarettes smoked per day were all independent predictors of the absolute neutrophil count and of the absolute lymphocyte count. Number of cigarettes smoked per day was the only smoking variable predictive of the absolute monocyte count and the absolute eosinophil count. When differential cell counts were considered as a percent of total leukocytes, the results were somewhat different. Neutrophils were disproportionately increased by current number of cigarettes smoked per day. Increased cigarette smoking decreased the proportion of white blood cells that were lymphocytes or eosinophils. Other smoking variables had no influence on percent counts for the specific white cell types in peripheral blood. These data suggest that the effect of cigarette smoking on differential cell counts is not uniform and is primarily influenced by current smoking behavior, although long-lasting effects of past smoking are also evident.

Adult↗
PubMed1994

Follow-up of asthma from childhood to adulthood: influence of potential childhood risk factors on the outcome of pulmonary function and bronchial responsiveness in adulthood.

The outcome of asthma in 406 children, aged 8 to 12 years, was studied. Follow-up in adulthood was 86%, with a mean age of 24.7 years and a mean interval of follow-up of 14.8 years. The predictive value of gender and various childhood variables on the adult level of pulmonary function (forced expiratory volume in 1 second [FEV1]) and bronchial responsiveness in adulthood was assessed. An increase in mean percent predicted FEV1 from childhood to adulthood was found, both in subjects with (76%) and without (24%) current respiratory symptoms. The only childhood variable predictive of adult level of FEV1 was the level of percent predicted FEV1 (p < 0.01). The proportion of subjects with a histamine provocative concentration causing a 10% decrease in FEV1 less than or equal to 16 mg/ml decreased significantly in adulthood. The degree of bronchial responsiveness had increased slightly in adults with symptoms (p = 0.87), whereas it had decreased significantly in subjects without symptoms (p < 0.01). Female subjects were significantly more responsive in adulthood than male subjects (p = 0.047). The childhood degree of bronchial responsiveness significantly predicted the presence of bronchial responsiveness in adulthood (p = 0.02). We conclude that childhood percent predicted FEV1 is relevant to predict the outcome of the adult pulmonary function level, whereas female gender and the childhood degree of bronchial responsiveness are important for the prediction of adult degree of bronchial responsiveness among children with asthma.

Asthma↗