Biomedical subjects

M D Lebowitz

Publications and source records attributed to M D Lebowitz.

At least 73 records · Page 4Linked to original sources

PubMed1991

Findings before diagnoses of asthma among the elderly in a longitudinal study of a general population sample.

Forty elderly subjects who denied ever having asthma or emphysema on enrollment in a longitudinal epidemiologic study later reported consulting a doctor for asthma when they were older than 60 years of age. The average age at which the diagnosis was reported was 70.8 years, after a mean follow-up of 8.5 years. Findings on enrollment in the newly diagnosed subjects with asthma are compared with findings in the 1145 subjects who provided follow-up information when they were older than age 60 years but had never developed asthma. At the time of enrollment, most subjects later diagnosed as having asthma already had wheezing symptoms, suggesting at least a mild asthmatic state, and many subjects had impaired ventilatory function, a positive allergy skin test (especially in association with rhinitis), and blood eosinophilia. Thirty-five percent of the subjects recalled "respiratory trouble before age 16" despite denying prior asthma. The likelihood of a new asthma label was very closely related to the age-sex-standardized serum-IgE level before diagnosis. Newly diagnosed subjects with asthma demonstrated much greater rates of decline in FEV1 than control subjects or than subjects who already had known asthma on enrollment. We conclude that (1) symptoms suggesting asthma are usually present for many years before the diagnosis of the disease in elderly subjects, (2) the serum-IgE level is closely related to the likelihood of a subsequent asthma diagnosis, even in this age group, and (3) a rapid fall in lung function often occurs around the time of initial diagnosis.

Age Factors↗

PubMed1991

Respiratory effects of non-tobacco cigarettes: a longitudinal study in general population.

Data from four consecutive surveys of Tucson longitudinal study of airways obstructive disease were used to examine the relation of respiratory symptoms and pulmonary function to non-tobacco cigarette smoking. The surveys were conducted over a six-year period and provided data on 1802 subjects 15-60 years of age, with a total of 5659 individual questionnaires. Estimated odds ratio (OR) of current non-tobacco smoking for chronic cough was 1.73, for chronic phlegm: 1.53, and for wheeze: 2.01 (p less than 0.05). These estimates were adjusted for age, tobacco smoking and occurrence of the symptom in preceding survey. The increased risk of the symptoms was related to the habit continued for several years, and there was no immediate remission of the symptoms after quitting smoking. A significant (p less than 0.05) reduction in pulmonary function (FEV1, Vmax50 and their ratios with FVC) was found a year or more after current non-tobacco smoking was reported. Although the average consumption of non-tobacco cigarettes, believed to be marijuana smoking, was less than one per day, significant effects were still detectable in both pulmonary function and respiratory symptoms.

Adolescent↗

PubMed1991

Relationship of respiratory symptoms and pulmonary function to tar, nicotine, and carbon monoxide yield of cigarettes.

The data from consecutive surveys of the Tucson Epidemiologic Study (1981-1988) were used to evaluate the relationship in cigarette smokers of respiratory symptoms and pulmonary function to tar, nicotine, and carbon monoxide (CO) yields of the cigarette. There were 690 subjects who reported smoking regularly in at least one survey, over age 15. After adjustment for intensity and duration of smoking and for depth of inhalation, the risk of chronic phlegm, cough, and dyspnea were not related to the tar and nicotine yields. In 414 subjects with pulmonary function tested in at least one of the three surveys the spirometric indices used were significantly related to the daily dose of tar, nicotine, and CO (product of the cigarette yield and daily number of cigarettes smoked). The effects were more pronounced for past than for current doses. However, the differentiation of pulmonary function due to various yields of cigarettes was small in comparison to the difference in pulmonary function between smokers and nonsmokers.

Age Factors↗

PubMed1991

The normal range of diurnal changes in peak expiratory flow rates. Relationship to symptoms and respiratory disease.

Measuring peak expiratory flow rates (PEFR) several times a day can provide an objective assessment of functional changes relative to environmental or occupational exposures. This report describes the pattern of diurnal changes in PEFR in a reference population, and defines ranges of "normal" between- and within-day variability. An index of diurnal changes was defined as the ratio between maximal and minimal values, where the maximal value was restricted to PEFR measured at noon or in the evening (N, E) and the minimal value was restricted to the morning or at bedtime (M, B). A ratio greater than normal represented an exaggeration of the normal diurnal pattern in PEFR. Normal limits, based on the ninety-fifth percentile in the reference population, were larger for children (130%) than for adults 15 to 35 yr of age (117%) and those older than 35 yr of age (118%). The meaningfulness of excessive diurnal changes in PEFR was examined by relating this ratio (Max/Min), and a similar measure (the amplitude percent mean) to chronic respiratory symptoms and diseases in 938 adults and children who recorded PEFR values 2 to 4 times per day for as long as 14 days. There was a strong relationship of diurnal changes in PEFR that exceed normal limits with physician-confirmed asthma (relative risk of 2.99 with Max/Min), with exertional dyspnea (Grade 2+), and with more frequent reporting of acute symptoms of wheeze, attacks of wheezing dyspnea, cough, and chest colds. In addition, those exceeding the normal limits had about 2.9 times greater risk of having a FEV1 below 80% of predicted, and nearly 7 times greater risk of being below 70%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Respiratory effects of occupational exposure in a general population sample in north Italy.

We assessed the effects of occupational exposure in a general population sample living in an unpolluted rural area of North Italy. In the age range of 18 to 64 yr, there were 417 participants who reported any exposure to dusts, chemicals, or gases and 1,218 who reported no exposure. Each subject completed a standardized interviewer-administered questionnaire (CNR-questionnaire). A variable proportion of participants succeeded in performing flow-volume curves, diffusing capacity of carbon monoxide, and slope of alveolar plateau of nitrogen. There was no significant difference for symptom prevalence rates between exposed and nonexposed in men and women who smoke. In nonsmoking women, those exposed showed significantly higher prevalence rates for exertional dyspnea and asthma. Regarding lung function, in exposed male smokers there was a significantly higher slope of the alveolar plateau. In exposed female nonsmokers, FEV1 and forced expiratory flows were significantly lower. Multiple logistic models in the overall group, accounting for age, smoking, and pack-years, showed that work exposure was associated significantly with higher risks for all symptoms in men (e.g., odds ratio: 2.76 for dyspnea, 2.31 for asthma, 1.69 for cough, and 1.64 for phlegm); in females, the association was significant for dyspnea (OR = 3.74) and asthma (OR = 3.29). Exposed men also had a significantly higher risk for %FEV1 or FEV1/FVC% below 70 (OR = 1.45). Our findings confirm those of the other few epidemiologic surveys in general population samples and contribute to the suggestion of a causal association between occupational exposure and chronic obstructive pulmonary disease.

Adult↗

PubMed1991

Smoking and symptom effects on the curves of lung function growth and decline.

Numerous studies have examined the natural time course of human lung function growth and decline throughout life. In most of these studies the investigators used statistical models that required a priori assumptions concerning the underlying form or structure of the lung function data, thus introducing possible biases. In this study we used recently developed nonparametric regression (spline) techniques to describe the evolution of lung function measures with age. This procedure yields an optimally fitted smooth curve through the data and estimates of the process velocity and does not require assumptions concerning the underlying shape of the data curves. The lung function growth-velocity curves are used to estimate the age of growth cessation. This technique was applied to the FVC, FEV1, and the FEV1/FVC ratios of 1,295 females and 1,230 males who were tested in at least one of the first nine surveys of the Tucson epidemiologic study of airway obstructive diseases. Data were analyzed stratified according to gender, smoking status, and respiratory symptoms or diseases. The results indicate large differences between the fitted FEV1 and FEV1/FVC smoothed curves of the various subgroups compared with asymptomatic nonsmokers. These differences were most pronounced in the adult symptomatic smokers, who had higher rates of lung function loss that also began at earlier ages, for both sexes. No significant differences were observed between asymptomatic and symptomatic nonsmokers, most likely because of the reduced number of symptomatic nonsmokers, particularly among the males.

Body Height↗

PubMed1991

Populations at risk: addressing health effects due to complex mixtures with a focus on respiratory effects.

Some individuals in the population may be sensitive or susceptible be to the effects of air pollutants. Such sensitivity may be to specific pollutants or classes of pollutants. However, sensitivity or susceptibility in some individuals can be to all irritants, but the sensitivity is likely to be response specific or organ specific. The U.S. Clean Air Act specifically recognizes that some individuals in the population are sensitive to air pollutants and indicates that such individuals need to be protected by air quality standards. It is usually difficult to determine the cause of sensitivity, though various biological mechanisms have been studied. Biological age may be a factor, with the young being most sensitive and susceptible to being affected. An example is the heightened bronchial lability and responsiveness in the very young that appears to disappear with growth. Susceptibility may be innate (e.g., genetic) and/or induced by events/exposures. Frequently, those with preexisting illnesses are part of the sensitive population because they may often respond, sometimes hyperrespond, to a pollutant exposure that may not affect most people. Asthmatics are excellent examples of individuals who were susceptible to the disease and, once inflicted, are susceptible to the effects of many environmental and nonenvironmental agents. Usually only a fraction of the general population will respond with heightened reactions at lower doses. Such individuals require special evaluation and attention in all exposure-response studies and risk assessments. Thus, the conditions defining populations at risk and the methodologies to discover and study them can be reviewed.

Air Pollutants↗

PubMed1991

Methods to assess respiratory effects of complex mixtures.

This paper evaluates the influence of exposures on acute and chronic airway obstruction. Clinical, physiological, and immunological aspects are important in evaluating the effects of the pollutant exposures. Aspects of the exposure-response relationships important enough to record are those factors interactive with the pollutants (e.g., smoking and other personal/behavioral factors) and precursor conditions. To determine baseline status and study chronic effects, one uses standardized and modified health questionnaires and standardized pulmonary function. Confirmatory studies of responsive airways, potentially assessed first by diurnal peak flow, can be done using post-bronchodilator maximum expiratory flow volume curves and methacholine challenges. Immunoglobulin determinations for immunological status (a predisposing/susceptibility factor), allergy skin tests (for immediate hypersensitivity status), and blood counts (mostly for eosinophils) are also important. Other tests that could be performed include expired carbon monoxide and/or carboxyhemoglobin and methemoglobin (for smoking and combustion exposures). Measures of acute effects are symptomatic responses (by questionnaires and diaries), responses of the airways (as measured by spirometry and peak flows), and changes in medication usage or associated medical care (in diaries). Methodologies should also include discussions of protocols and analysis.

Air Pollutants↗

PubMed1991

Prevalence rates of respiratory symptoms in Italian general population samples exposed to different levels of air pollution.

We surveyed two general population samples aged 8 to 64 living in the unpolluted, rural area of the Po Delta (northern Italy) (n = 3289) and in the urban area of Pisa (central Italy) (n = 2917). Each subject filled out a standardized interviewer-administered questionnaire. The Pisa sample was divided into three groups according to their residence in the urban-suburban areas and to outdoor air pollution exposure (automobile exhaust only or industrial fumes as well). Significantly higher prevalence rates of all the respiratory symptoms and diseases were found in Pisa compared with the Po Delta. In particular, rhinitis and wheezing symptoms were higher in all the three urban zones; chronic cough and phlegm were higher in the zone with the automobile exhaust and the additional industrial exposure. Current smoking was more frequent in the rural area, but the urban smokers had a higher lifetime cigarette consumption. Childhood respiratory trouble and recurrent respiratory illnesses were evenly distributed. Exposure to parental smoking in childhood and lower educational level were more frequent in Po Delta, whereas familial history of respiratory/allergic disorders and work and indoor exposures were more often reported in the city. Multiple logistic regression models estimating independently the role of the various risk factors showed significant odds ratios associated with residence in Pisa for all the symptoms but chronic phlegm. For example, those living in the urban-industrial zone had an odds ratio of 4.0 (4.3-3.7) for rhinitis and 2.8 (3.0-2.6) for wheeze with respect to those living in the Po Delta.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Characteristics of asthma among elderly adults in a sample of the general population.

This article describes the characteristics and course of asthma among subjects who were older than 65 years at the time of enrollment in a longitudinal study of a general population sample. It was present in 3.8 percent of men and 7.1 percent of women. An additional 4.1 percent of men reported having "asthma," but they also had seen a physician for "emphysema" and had smoked significantly; their "asthma" diagnosis is regarded as highly questionable. They did not show the elevated rate of allergy skin test reactivity of high serum IgE levels that were characteristic of other asthmatics. Many of the elderly asthmatics (mean age, 72 years) had severe disease with marked ventilatory impairment. There was a close relationship between the severity of wheezing complaints and impairment of the FEV1. Of the 46 patients, 48 percent reported an onset before age 40 years. There was no relationship between severity and age of onset or duration of disease. A second diagnosis of "chronic bronchitis" was reported by 46 percent of the asthmatics, but this did not delineate a distinctive group with late-onset, smoking-related disease. Death rates in the asthmatics tended to be higher than in nonasthmatics (odds ratio, 1.9; CI, 0.998 to 3.70, after stratifying by sex). Over a mean follow-up of 7.44 years, most symptoms as well as the FEV1 remained relatively stable. Chronic productive cough did tend to remit (p less than 0.01), but this was noted in the nonasthmatics as well. We estimate that no more than 19 percent of the asthmatics went into complete remission during follow-up. Most of these had mild initial symptoms; there were no remissions in subjects with severe disease at the time of entry. We concluded that asthma in the elderly is not a rare disease and may be associated with severe symptoms and chronic airways obstruction. If severe, it rarely goes into complete remission but tends to remain a severe, disabling disorder.

Aged↗

PubMed1991

Respiratory symptoms and risk factors in an Arizona population sample of Anglo and Mexican-American whites.

Prevalence rates of respiratory symptoms and diseases in a large group of Anglos and Mexican-Americans were analyzed. Each subject completed a questionnaire. Among current smokers, chronic productive cough and dyspnea were significantly higher in both ethnic groups; wheezy symptoms were higher in Anglos. There were no significant differences in the symptom prevalence rates between the two groups, after stratifying by current cigarette consumption and CRT. The spirometric values were not significantly different. In both ethnic groups, the prevalence rates of wheeze, SOBWHZ and asthma were significantly higher in those who had CRT. Among Anglos, less educated smokers had significantly higher prevalence rates of SOBWHZ and dyspnea; nonsmokers with less education had higher prevalence rates of cough, chronic cough and dyspnea. Our results confirm the importance of CRT and lower educational level as risk factors for respiratory symptoms. Ethnicity is not associated with symptomatology or lung function impairment.

Adult↗

PubMed1991

Exposure assessment approaches to evaluate respiratory health effects of particulate matter and nitrogen dioxide.

Several approaches can be taken to estimate or classify total personal exposures to air pollutants. While personal exposure monitoring (PEM) provides the most direct measurements, it is usually not practical for extended time periods or large populations. This paper describes the use of indirect approaches to estimate total personal exposure for NO2 and particulate matter (PM), summarizes the distributions of these estimates, and compares the effectiveness of these estimates with microenvironmental concentrations for evaluating effects on respiratory function and symptoms. Pollutant concentrations were measured at several indoor and outdoor locations for over 400 households participating in an epidemiological study in Tucson, Arizona. Central site monitoring data were significantly correlated with samples collected directly outside homes, but the former usually had higher pollutant concentrations. Integrated indices of daily total personal exposure were calculated using micro-environmental (ME) measurements or estimates and time-budget diary information. Peak expiratory flow rates (PEFR) were measured for up to four times a day during two-week study periods. In thirty children (ages 6-15 years) with current diagnosed asthma, a significant reduction in PEFR was associated with NO2 levels measured outside of their homes. Additional decrements of morning PEFR were found in those children sleeping in bedrooms with higher measured NO2 levels. Morning and noon PEFR decrements were also linked to higher morning NO2 levels that were measured at central monitoring stations. Effects of PM were also found, but were limited to morning PEFR. No effects were found in non-asthmatic children. The relationship of PEFR to the calculated indices of daily average total exposure were weaker than to the microenvironment concentrations. This suggests that diary and ME monitoring data need to yield better time resolution in order to incorporate short-term average exposures to higher concentrations into the exposure indices and into the analysis of within day health responses.

Adolescent↗

PubMed1991

Effects of home environment on respiratory symptoms and lung function in a general population sample in north Italy.

Effects of indoor pollution exposure were evaluated in a general population sample (n = 3,289) living in the Po River Delta area. Prevalence rates of chronic cough in men and dyspnoea in women were significantly higher in association with the use of bottled gas (propane) for cooking instead of natural gas (methane). Chronic cough and phlegm in men and dyspnoea in women were significantly associated with the use of a stove for heating. When combining type of heating and fuel used, in men a trend toward higher prevalence rates of chronic cough and phlegm was shown in those with stove or fan heating (regardless of the fuel); in women the trend reached statistical significance for dyspnoea. The relationship between stove (regardless of fuel) and decrease in forced expirograms was statistically significant only in women. In multiple logistic models, accounting for independent effects of age, smoking, pack-years, parents' smoking, socio-economic status, body mass index, significantly increased odds ratios were found in males for the associations of: bottled gas for cooking with cough (1.66) and dyspnoea (1.81); stove for heating with cough (1.44) and phlegm (1.39); stove fuelled by natural gas and fan or stove fuelled other than by natural gas with cough (1.54 and 1.66). In females, significantly increased odds ratios were found only for dyspnoea when associated with bottled gas for cooking (1.45), stove for heating (1.46), stove fuelled by natural gas (1.58), stove or fan fuelled other than by natural gas (1.73).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1990

Differential rates of lung growth as measured longitudinally by pulmonary function in children and adolescents.

A sample population of 67 males and 71 females with longitudinal lung function and other anthropometric measurements from all non-Hispanic white children in the Tucson Epidemiological Study of Airway Obstructive Diseases (AOD) was studied to evaluate biological determinants of the rate of lung growth. Groups within gender were defined by the following factors: 1) maximum height, 2) age at maximum forced expiratory volume at 1 second (FEV1), 3) % predicted initial FEV1 or FEV1/FVC ratio. Only groups defined by low initial function (FEV1 or FEV1/FVC less than or equal to 85% predicted versus greater than 85% predicted) showed statistically significant differences from those with more "normal" function by comparing their maximum % of predicted FEV1s and FEV1/FVC ratios. The longitudinal FEV1 data by age for the latter groups were characterized by a mathematical model (polynomial smoothing spline) yielding optimal fitted curves and an estimate of each group's growth velocity curve. The statistical comparisons between these fitted curves indicate that subjects with low initial pulmonary function continued to have significantly lower FEV1 values for males older than 13.12 years and for females between 8.23 and 15.3 years. At post-hoc analysis persistent wheezing was more likely in the initially more impaired group. Disease at the end of follow-up was not related to initial functional status.

Adolescent↗

PubMed1990

The Po River Delta epidemiological study of obstructive lung disease: sampling methods, environmental and population characteristics.

A longitudinal study on chronic obstructive lung disease (AOD) has been started in the Po River Delta in northern Italy. The first cross-sectional study was conducted in this previously unpolluted rural area before the start of operation of a large thermoelectric power plant (2,649 megawatt). A significant output of air pollutants is expected. This will permit us to carry out a "natural experiment" to study the effects of air pollutants (SO2 and suspended particulates). A multistage stratified cluster design was chosen. Stratification was based on age and socio-economic characteristics (SES) of households, and was performed in two steps, using the different indices computed from the census data. Geographic zones represented four areas of different predicted pollution exposure, once the plant started operating. There were 3,289 subjects in the selected age group (8-64) who agreed to participate (78%); only 11% refused to participate. The participants were representative of the clusters and SES. Participants had slightly fewer employed males, who did not participate due to work. The stratification and staging method allowed us to keep an acceptable level of precision and efficiency in the sample. In fact age-related differences were not found among the SES strata and geographic zones; various socio-economic characteristics, verified from the questionnaire information, were consistent with the SES stratification. Differences between geographic zones were related to the number of households of different SES within clusters; however this reflects the characteristics of the general population in the area.

Air Pollutants↗

PubMed1990

A longitudinal study of risk factors in asthma and chronic bronchitis in childhood.

The prevalence, persistence, incidence and remission rates of reported diagnosed asthma and chronic bronchitis has been studied longitudinally over ten years in a representative community sample of children and adolescents. The objectives are to evaluate the rates of change over time, the role of family history of disease, and the social risk factors in the longitudinal course of disease. The relationship between the two reported diagnoses is very high, about half of each group having the other diagnosis. Each diagnosis has specific symptoms with which it is associated. Remission of clinical disease is associated with continuing symptoms in about half of such cases. The incidence rates and remissions of cases as they have occurred over time were associated with different symptoms and risk factors. A family history of lung disease and family social characteristics are significant risk factors affecting the presence of these diseases, and how they change. Discussion suggests these factors may affect possible precursors, such as lower respiratory tract illnesses, as well as personal habits (such as smoking), which are related to both diagnoses. Further, the interactions of these risk factors appear to significantly influence impairments of lung function at the beginning of adult life, and potential subsequent disease.

Adolescent↗

PubMed1990

An association of human congenital cardiac malformations and drinking water contaminants.

During an informal study in 1973 it was noted that approximately one third of patients with congenital heart disease lived in a small area in the Tucson Valley. In 1981 groundwater for a nearly identical area was found to be contaminated with trichloroethylene and to a lesser extent with dichloroethylene and chromium. Contamination probably began during the 1950s. Affected wells were closed after discovery of contamination. This sequence of events allowed investigation of the prevalence of congenital heart disease in children whose parents were exposed to the contaminated water area as compared with children whose parents were never exposed to the contaminated water area. The contaminated water area contained 8.8% of the Tucson Valley population and 4.5% of the labor force. Using their case registry, the authors interviewed parents of 707 children with congenital heart disease who, between 1969 and 1987, 1) conceived their child in the Tucson Valley, and 2) spent the month before the first trimester and the first trimester of the case pregnancy in the Tucson Valley. Two random dialing surveys showed that only 10.5% of the Tucson Valley population had ever had work or residence contact, or both, with the contaminated water area, whereas 35% of parents of children with congenital heart disease had had such contact (p less than 0.005). The prevalence of congenital cardiac disease (excluding syndromes, children with atrial tachycardia or premature infants with patent ductus arteriosus) in the Tucson Valley was 0.7% of live births and with syndromes was calculated to be 0.82%. The odds ratio for congenital heart disease for children of parents with contaminated water area contact during the period of active contamination was three times that for those without contact (p less than 0.005) and decreased to near unity for new arrivals in the contaminated water area after well closure. The proportion of infants with congenital heart disease as compared with the number of live births was significantly higher for resident mothers in the contaminated water area than for mothers with no exposure. No other environmental agent could be identified that was localized to the contaminated water area, but one could have been missed. The data show a significant association but not a cause and effect relation between parental exposure to the contaminated water area and an increased proportion of congenital heart disease among live births as compared with the proportion of congenital heart disease among live births for parents without contaminated water area contact.

Adult↗

PubMed1990

Chronic respiratory effects of indoor formaldehyde exposure.

The relation of chronic respiratory symptoms and pulmonary function to formaldehyde (HCHO) in homes was studied in a sample of 298 children (6-15 years of age) and 613 adults. HCHO measurements were made with passive samplers during two 1-week periods. Data on chronic cough and phlegm, wheeze, attacks of breathlessness, and doctor diagnoses of chronic bronchitis and asthma were collected with self-completed questionnaires. Peak expiratory flow rates (PEFR) were obtained during the evenings and mornings for up to 14 consecutive days for each individual. Significantly greater prevalence rates of asthma and chronic bronchitis were found in children from houses with HCHO levels 60-120 ppb than in those less exposed, especially in children also exposed to environmental tobacco smoke. In children, levels of PEFR decreased linearly with HCHO exposure, with the estimated decrease due to 60 ppb of HCHO equivalent to 22% of PEFR level in nonexposed children. The effects in asthmatic children exposed to HCHO below 50 ppb were greater than in healthy ones. The effects in adults were less evident: decrements in PEFR due to HCHO over 40 ppb were seen only in the morning, and mainly in smokers.

Adolescent↗