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Biomedical subjects

J Sunyer

Publications and source records attributed to J Sunyer.

At least 109 records · Page 6Linked to original sources
PubMed1997

Risk factors for asthma in young adults. Spanish Group of the European Community Respiratory Health Survey.

We assessed the association of asthma prevalence in young adults with susceptibility factors and environmental exposures, taking into account the age at asthma onset. A random sample of the general population, aged 20-44 yrs, in five areas of Spain (Albacete, Barcelona, Galdakao, Huelva, and Oviedo) was selected in the frame of the European Community Respiratory Health Survey (ECRHS). Overall, 2,646 subjects (response rate = 60.9%) responded to a respiratory questionnaire and 1,797 (41.4%) finalized a bronchial challenge. Atopy to perennial (odds ratio (OR) = 10.2, 95% confidence interval 4.2-25) and seasonal allergens (11.5, 4.6-28), parental asthma (4.5, 2.5-8.4), and birth order (OR for no older siblings in comparison to having more than two = 3.2, 1.2-9.1) were associated with current asthma whatever the age of asthma onset. Past asthma was associated to a lesser extent with atopy (OR around 3.5 to both perennial and seasonal allergens). Lower respiratory tract infections before the age of 5 yrs (LRTI), having had a pet in childhood, and being born in a younger cohort were associated with asthma starting before the age of 15 yrs, but not after. Male gender was more frequent in childhood asthma and female gender in adulthood. In addition to the known risk factors of asthma (atopy to perennial allergens, parental asthma) we provide evidence for an association of asthma (whatever the age of onset) with sensitization to seasonal allergens, and having less than three older siblings; and for an association of childhood asthma with lower respiratory tract infections.

Adult↗
PubMed1997

Metabolism of hexachlorobenzene in humans: association between serum levels and urinary metabolites in a highly exposed population.

Serum and urine from 100 subjects of a general population highly exposed to airborne hexachlorobenzene (HCB) were analyzed to obtain new insights into the metabolism of this ubiquitous compound. HCB was detected in all serum samples with concentrations ranging between 1.1 and 953 ng/ml. The major known metabolites of HCB were investigated in urine collected over 24 hr. Pentachlorophenol (PCP) was detected in all urines with values ranging between 0.58 and 13.9 micrograms excreted in 24 hr [mean +/- standard deviation (SD), 2.52 +/- 2.05; geometric mean, 2.05]. A sulfur derivative that, after hydrolysis, yielded pentachlorobenzenethiol (PCBT) could also be identified and quantified in all the urines with values ranging between 0.18 and 84.0 micrograms of PCBT excreted in 24 hr (mean +/- SD, 3.47 +/- 10.8; geometric mean, 1.39). The sulfur derivative assessed as PCBT appeared to be the main metabolite, with urinary concentrations surpassing those of PCP in the subjects with higher HCB accumulation (HCB in serum > 32 ng/ml). PCBT concentration in urine collected over 24 hr showed a very strong association with HCB concentration in serum; the association was stronger in males than in females. An increase of 1 ng/ml of HCB in serum led to an increase of 2.12 micrograms of PCBT excreted in urine collected over 24 hr in males (95% CI, 1.82-2.44) and to an increase of 0.67 microgram of PCBT in females (CI, 0.33-1.09). A weaker association was found between PCP in urine and HCB in serum, which was only statistically significant in males (an increase of 1 ng/ml of HCB in serum led to an increase of 0.63 microgram of PCP excreted in urine collected over 24 hr; (CI, 0.34-0.95). These results show that the formation of the cysteine conjugate is a quantitatively more important metabolic pathway in humans than the formation of PCP. Moreover, the association found suggests that PCBT is a good urinary marker of HCB internal dose and glutathione-mediated metabolism.

Air Pollutants↗
PubMed1996

Longitudinal relation between smoking and white blood cells.

Higher white blood cell counts in smokers compared with nonsmokers have been well documented, but the longitudinal relation between changes in smoking and changes in white blood cells has not been well described. Since 1984, data have been collected semiannually by the Multicenter AIDS Cohort Study (MACS), a four-center prospective cohort study of acquired immunodeficiency syndrome (AIDS) in homosexual men. The study population includes 2,435 participants who were human immunodeficiency virus (HIV) seronegative as of September 1994 and who contributed 20,918 person-visits for this analysis. For individuals who modified their smoking behavior, changes in white blood cell counts occurred primarily during the first 6 months following changes in the amount of cigarettes smoked. Among former smokers who resumed smoking, the extent of the increase in white blood cell count depended on the number of cigarettes smoked. Specifically, increases of 241, 340, and 740 cells/microliter were observed for smokers who resumed smoking < 1, 1 to < 2, and > or = 2 packs/day, respectively. Conversely, smokers who quit smoking had a decrease of white blood cell count: -32, -629, and -1,122 cells/microliter for men who previously smoked < 1, 1 to < 2, and > or = 2 packs/day, respectively. Long-term ex-smokers, however, still had higher white blood cell counts than did never smokers. There was a high within-individual correlation of white blood cell count in persons who reported a consistent level of smoking (i.e., average correlations between two white blood cell counts 6 years apart were 0.51 for never smokers, 0.48 for ex-smokers, 0.56 for men who smoked < 1 pack/day, and 0.43 for men who smoked > or = 1 pack/day). These analyses indicate an acute effect of changes in smoking on changes in white blood cell count, a residual effect of having been a smoker, and high long-term tracking for white blood cell count.

Adult↗
PubMed1996

Cohort study on cancer mortality among workers in the pulp and paper industry in Catalonia, Spain.

We examined mortality in a retrospective follow-up study of 3,241 workers employed between 1970-1992, in four pulp and paper mills in Catalonia, Spain. Vital status was determined for 95% of the cohort. Exposure was reconstructed using job histories and a company exposure questionnaire. Standardized mortality ratios (SMR) were derived using mortality rates of Spain as the reference. For all workers, mortality from all causes (SMR = 76; 95%; confidence intervals [CI] = 65-88; 189 deaths) and all malignant neoplasms (SMR = 93; CI = 72-119; 65 deaths) were less than the expected. Excess risk was observed for mortality from all neoplasms in females (SMR = 168; CI = 84-303; 11 deaths), for large intestine cancer in both sexes (SMR = 250; CI = 115-525; 8 deaths), particularly after 10 years of employment and latency (SMR = 355; CI = 154-701; 8 deaths), and for breast cancer in females (SMR = 286; CI = 77-732; 4 deaths). These findings suggest that workers employed in the pulp and paper industry may have an excess risk of specific cancers.

Adult↗
PubMed1996

Air pollution and mortality in Barcelona.

STUDY OBJECTIVES: Studies conducted in Barcelona reported a short term relation between daily air pollutant values and emergency department admissions for exacerbation of chronic obstructive pulmonary diseases and asthma. Air pollution in Barcelona is mainly generated by vehicle exhaust and is below the World Health Organization air quality guidelines. The acute relation between air pollution and mortality was assessed. DESIGN: Daily variations in total mortality, mortality in subjects older than 70 years, and cardiovascular and respiratory mortality were related with daily variations in air pollutants for the period 1985-91, using autoregressive Poisson regression models that allow to control for temperature, relative humidity and variables handling temporal and autoregressive patterns. MAIN RESULTS: Black smoke and sulphur dioxide (SO2) were related to total mortality (relative risks (RR) for 100 micrograms/m3 = 1.07 and 1.13 respectively), elderly mortality (RR = 1.06 and 1.13), cardiovascular mortality (RR = 1.09 and 1.14), and respiratory mortality (RR = 1.10 and 1.13); all the associations being statistically significant, except for respiratory mortality (p = 0.07). The association between SO2 and respiratory mortality was stronger in summer (1.24, p < 0.01) than in winter (1.08, p > 0.1). Oxidant pollutants (nitrogen dioxide and ozone) were positively related with elderly mortality (RR = 1.05 and 1.09, respectively) and cardiovascular mortality (RR = 1.07 and 1.09) during the summer (p < 0.05), but not during the winter. CONCLUSIONS: Current air pollutant levels were related to mortality in Barcelona. These results were consistent with similar studies in other cities and coherent with previous studies with emergency room admissions in Barcelona.

Age Factors↗
PubMed1996

Concentrations of methacholine for bronchial responsiveness according to symptoms, smoking and immunoglobulin E in a population-based study in Spain. Spanish Group of the European Asthma Study.

To assess the simultaneous effects of symptoms related to asthma, smoking, and Immunoglobulin E (IgE) on the concentrations of methacholine at which different individuals fall below 80% the FEV1 values obtained with saline, we used parametric survival methods that fit the dose-response nature of bronchial responsiveness (BR). A general population-based sample of 1,615 adults (aged 20 to 44 yr) from five cities in Spain participating in the European Community Respiratory Health Survey was studied. The total number of subjects whose FEV1 values dropped below 80% was 237 (14.7%). We found that individuals with symptoms related to asthma, whether they were smokers or nonsmokers, responded at lower concentrations of methacholine than individuals without symptoms. The greatest decrease in the concentrations of methacholine at which different percentages of individuals responded was due to symptoms among the nonsmokers (relative percentiles ranging from 0.53 to 0.76, and a 90% confidence band not containing a value one). Among individuals without symptoms, smokers responded at moderately but significantly lower concentrations than nonsmokers, whereas an apparent protective effect of smoking was seen in symptomatic individuals, owing in part to a self-selection bias. The higher the concentration of IgE, the lower were the concentrations of methacholine needed to obtain a given level of BR. Moreover, the magnitude of the decrease in methacholine concentrations leading to a response was constant over all percentages of individuals responding. The analytical methods used in the study permit the incorporation of complexities in the relationships between BR and symptoms, smoking, and IgE, and are generally applicable to situations in which a dose-response relationship occurs.

Adult↗
PubMed1996

Atopy and nonspecific bronchial responsiveness. A population-based assessment. Spanish Group of the European Community Respiratory Health Survey.

The relative importance of specific immunoresponse in explaining nonspecific bronchial responsiveness (BR) has scarcely been examined. We provide quantitative estimates of the proportion of BR attributable to specific atopy to different common aeroallergens. We used data from a cross-sectional study on a random sample of the general population 20 to 44 yr of age from five Spanish areas. There were 1,816 participants who performed a methacholine challenge and had atopy assessed. BR was defined as a 20% or more fall in FEV1. Atopy was assessed by measuring serum-specific IgE or skin tests to cat, Dermatophagoides pteronyssinus, Cladosporium, Alternaria, timothy grass, olive, birch, Parietaria, or ragweed. The strongest associations between BR and specific IgE response were against timothy grass (prevalence rate ratio = 1.78; 95% confidence interval 1.2 to 2.6), Dermatophagoides pteronyssinus = 1.64 (1.2 to 2.2), and olive = 2.36 (1.5 to 3.7), all after adjustment by age, sex, area of residence, smoking, and a positive response to any of the other eight allergens measured. The population attributable risk of BR for a positive response to any of the nine allergens measured was 20.96% (10.2 to 43.2%) when adjusting for area of residence, age, sex, and smoking. Nonspecific bronchial responsiveness in the general population was found to be related to atopy against single specific allergens, but the population risk attributable to atopy may be lower than previously suggested.

Adult↗
PubMed1996

Immunopathology of fatal soybean dust-induced asthma.

A hypothesis was postulated that the characteristic clinical course of fatal soybean asthma may be reflected by specific immunopathological findings. Seven cases of fatal soybean dust-induced asthma from Barcelona, Spain were compared with 25 fatal asthma cases from New Zealand. Sections of lung tissue were stained by monoclonal antibodies using standard streptavidin-biotin peroxidase technique. The following cell types were identified: mast cells, "activated" eosinophils, neutrophils, monocytes/macrophages, CD3+ T-cells and CD8+ T-cells. The positively staining cells were counted in the epithelium and the submucosa and their numbers expressed per mm and mm2, respectively. The airways were divided into larger (internal perimeter (Pi) > 2 mm) and smaller (Pi < 2 mm). Firstly, all airways were studied together; and subsequently, larger and smaller airways were studied separately. Differences in the numbers of mast cells, eosinophils, neutrophils and monocytes/macrophages between the two groups were not significant. The numbers of CD3+ and CD8+ T-cells were significantly reduced in fatal soybean asthma when all airways were taken together. In larger airways, the difference was not significant in the epithelium, but was significant in the submucosa for CD3+ cells. CD8+ cells were significantly reduced in fatal soybean asthma both in the epithelium and the submucosa. The cell counts in smaller airways were not significantly different either in the epithelium or in the submucosa for CD3+ cells. The numbers of CD8+ cells were not different in the epithelium, but were significantly reduced in the submucosa of fatal soybean asthma cases. We conclude that the numbers of CD3+ and CD8+ T-cells are substantially reduced in fatal soybean asthma. These data together with the clinical features of the fatal attack suggest a different mechanism(s) from that described for most asthma deaths, probably involving anaphylaxis.

Adult↗
PubMed1996

Total serum IgE is associated with asthma independently of specific IgE levels. The Spanish Group of the European Study of Asthma.

In this study we aimed to assess whether the association between asthma (defined by symptoms and bronchial responsiveness) and total immunoglobulin E (IgE) levels was independent of specific IgE levels to common aeroallergens. A general population-based sample, supplemented with symptomatic individuals, comprising 1,916 young adults, aged 20-44 years, from five areas of Spain, performed a face-to-face respiratory questionnaire, and spirometry, and had total and specific serum IgE levels to mites, pets and moulds recorded. In 1,626 of the subjects, a dose-response methacholine challenge test was completed. Subjects reporting current attacks of asthma showed an association with total IgE (odds ratio (OR) for IgE > 100 kU.L-1 = 4.73, 95% confidence intervals (95% CI) = 2.01-11.12, adjusted for specific IgE, sex, age, smoking, forced expiratory volume in one second (FEV1), and area), which did not vary by bronchial responsiveness. The association between total IgE and asthma also occurred among those with negative specific IgE antibodies (OR 18.0; 95% CI 13.9-120). Individuals with current wheezing and bronchial responsiveness without attacks of asthma also showed an adjusted association with total IgE (OR 4.96; 95% CI 2.32-10.6), which remained for persons without specific IgE (OR 5.86; 95% CI 2.18-1.7). These findings reinforce previous evidence that asthma is associated with increased levels of total IgE, even in subjects negative for specific IgE to common aeroallergens.

Adult↗
PubMed1996

Prevalence of asthma-related symptoms and bronchial responsiveness to exercise in children aged 13-14 yrs in Barcelona, Spain.

It is not clear whether asymptomatic bronchial responsiveness is a risk factor for development of asthma. A cross-sectional study was conducted to determine the prevalence of asthma among schoolchildren from Barcelona (Spain). The association between respiratory symptoms and bronchial responsiveness to exercise was examined. For this study 3,033 schoolchildren aged 13-14 yrs were studied from the general population. Participants answered a respiratory questionnaire and a self-reporting video-questionnaire. A total of 2,842 children underwent bronchial responsiveness testing by exercise challenge. The study was part of the International Study of Asthma and Allergies in Childhood (ISAAC) project. The prevalence of "current asthma" (recent wheezing and bronchial responsiveness to exercise) was 4% and the prevalence of "wheezing only" 10%. A fall in peak expiratory flow rate (PEFR) > or = 15% after exercise testing was found in 324 (11%) children, 29 (9%) of whom presented clinical symptoms of asthma. Bronchial responsiveness to exercise was significantly associated with all items of the asthma questionnaire. The prevalence of asthma-related symptoms in this inner-city area was lower than frequently reported rates in other countries, although the prevalence of exercise-induced bronchoconstriction was relatively high, and threefold greater than in a geographical area in the vicinity of Barcelona. These findings are consistent with the current view that asthma-related symptoms and bronchial responsiveness to exercise have different meanings in a community survey, and that local environmental factors could influence the prevalence of bronchial responsiveness.

Adolescent↗
PubMed1996

Benzene exposure, assessed by urinary trans,trans-muconic acid, in urban children with elevated blood lead levels.

A pilot study was performed to evaluate the feasibility of using trans,trans-muconic acid (MA) as a biomarker of environmental benzene exposure. A secondary aim was to provide data on the extent of exposure to selected toxicants in a unique population consisting of inner-city children who were already overexposed to one urban hazard, lead. Potential sources of benzene were assessed by a questionnaire. Exposure biomarkers included urinary MA and cotinine and blood lead. Mean MA was 176.6 +/- 341.7 ng/mg creatinine in the 79 children who participated. A wide range of values was found with as many as 10.1%, depending on the comparison study, above the highest levels reported in adults not exposed by occupation. Mean MA was increased in children evaluated in the afternoon compared to morning, those at or above the median for time spent playing near the street, and those studied in the first half of the investigation. MA levels were not associated with blood lead or, consistently, with either questionnaire environmental tobacco smoke (ETS) data or cotinine. As expected, the mean blood lead level was elevated (23.6 micrograms/dl). Mean cotinine was also increased at 79.2 ng/mg creatinine. We conclude that the use of MA as a biomarker for environmental benzene exposure is feasible since it was detectable in 72% of subjects with a wide range of values present. In future studies, correlation of MA with personal air sampling in environmental exposure will be essential to fully interpret the significance of these findings. In addition, these inner-city children comprise a high risk group for exposure to environmental toxicants including ETS, lead, and probably benzene, based on questionnaire sources and its presence in ETS.

Benzene↗
PubMed1996

Environmental tobacco smoke exposure in inner-city children.

Exposure to environmental tobacco smoke (ETS) was assessed as part of a pilot study aimed at determining the extent of multiple toxicant exposures in children from inner-city areas of Baltimore, MD. Questionnaire data on sources of ETS and urinary cotinine were obtained in children considered at high risk for urban exposures because of previous or current overexposure to one inner-city environmental hazard, lead. Fifty-three (67.1%) of the 79 participants were exposed to ETS in the preceding 48 h as assessed by questionnaire. Cotinine was present in 77 (98.7%) of the 78 samples assayed with a mean of 79.2 ng/mg creatinine (54.7 ng/ml). Eighty % of children had cotinine values > or = 30 ng/mg creatinine, a level commonly associated with household ETS exposure. Levels in children without reported ETS exposure in their homes were also elevated (mean = 45.0 ng/mg creatinine). As expected, blood lead levels were elevated with a mean of 23.6 micrograms/dl. We conclude that these inner-city children have substantial exposures to both ETS and lead. Furthermore, the presence of elevated cotinine levels in children without known household exposure suggests that ETS should be considered an urban toxicant as well as an individual residential exposure.

Baltimore↗
PubMed1995

Diagnosis of soybean-induced asthma.

BACKGROUND: The role of soybean dust as a causal agent of asthma has been clearly established since the Barcelona asthma epidemics in the 1980s. The large number of patients who were first seen with asthma symptoms during those epidemics provided an excellent opportunity to study the possibilities of different diagnostic tests. OBJECTIVE: This study was designed to evaluate the usefulness of the skin test and amplified ELISA technique for quantifying specific IgE in the diagnosis of soybean asthma. PATIENTS AND RESULTS: Ninety epidemic asthmatic patients and 95 nonepidemic asthmatic patients were studied 2 years after the last epidemic. Results of prick tests and ELISAs for specific IgE with hull and dust extracts showed a significant difference between the two groups of patients (p < 0.001). Sensitivity and specificity of glycerinated prick test with hull extract in epidemic asthmatic patients were 57.7% and 95.3%, respectively, and ELISA values were 56.6% and 93.7%, respectively. Similar results were obtained with dust extracts. CONCLUSION: Glycerinated skin prick tests and ELISAs with soybean hull and dust extracts have proved effective in the diagnosis of soybean asthma, even 2 years after the epidemics. Taking into account the sensitivity (90.5%) and specificity (93.7%) of ELISA test results for epidemic asthmatic patients found when the epidemic occurred, data from this study suggest that both tests may be very useful for the diagnosis of soybean dust-induced asthma.

Asthma↗
PubMed1995

Relationship between serum IgE and airway responsiveness in adults with asthma.

BACKGROUND: General population studies have shown a relationship between total serum IgE levels and airway responsiveness, but this association has not been documented in patients with asthma. OBJECTIVE: The study assesses the cross-sectional relationship between IgE levels and airway responsiveness in 208 subjects who had had emergency department treatment for asthma at least 2 years earlier. METHODS: All participants completed a standardized respiratory questionnaire and underwent spirometry, allergy skin testing, and a dose-response methacholine challenge test. RESULTS: After adjusting for age and gender, the percentage of patients with asthma and airway responsiveness (provocative concentration causing a 20% fall in forced expiratory volume in 1 second [PC20] < or = 8 mg/ml) increased from 52% in the lower quintile of IgE to 72% in the upper quintile (p < 0.01). After adjusting for age, gender, baseline percent predicted forced expiratory volume in 1 second, and smoking, the association between IgE (both in quintiles and continuous) and PC20 appeared consistent and statistically significant (p < 0.01). This association was stronger in patients who were not given inhaled steroid (odds ratio for twice the concentration of IgE, 1.42; 95% confidence interval, 1.09 and 1.84), than in patients treated with inhaled steroid (odds ratio, 1.10; 95% confidence interval, 0.82 and 1.50). Eosinophilia and skin reactivity were associated with PC20 although to a lesser extent. CONCLUSION: These findings strengthen the role played by IgE in facilitating the development of bronchial responsiveness in patients with asthma.

Administration, Inhalation↗