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M D Lebowitz

Publications and source records attributed to M D Lebowitz.

At least 19 recordsLinked to original sources
PubMed2000

Association of sleep-disordered breathing, sleep apnea, and hypertension in a large community-based study. Sleep Heart Health Study.

CONTEXT: Sleep-disordered breathing (SDB) and sleep apnea have been linked to hypertension in previous studies, but most of these studies used surrogate information to define SDB (eg, snoring) and were based on small clinic populations, or both. OBJECTIVE: To assess the association between SDB and hypertension in a large cohort of middle-aged and older persons. DESIGN AND SETTING: Cross-sectional analyses of participants in the Sleep Heart Health Study, a community-based multicenter study conducted between November 1995 and January 1998. PARTICIPANTS: A total of 6132 subjects recruited from ongoing population-based studies (aged > or = 40 years; 52.8% female). MAIN OUTCOME MEASURES: Apnea-hypopnea index (AHI, the average number of apneas plus hypopneas per hour of sleep, with apnea defined as a cessation of airflow and hypopnea defined as a > or = 30% reduction in airflow or thoracoabdominal excursion both of which are accompanied by a > or = 4% drop in oxyhemoglobin saturation) [corrected], obtained by unattended home polysomnography. Other measures include arousal index; percentage of sleep time below 90% oxygen saturation; history of snoring; and presence of hypertension, defined as resting blood pressure of at least 140/90 mm Hg or use of antihypertensive medication. RESULTS: Mean systolic and diastolic blood pressure and prevalence of hypertension increased significantly with increasing SDB measures, although some of this association was explained by body mass index (BMI). After adjusting for demographics and anthropometric variables (including BMI, neck circumference, and waist-to-hip ratio), as well as for alcohol intake and smoking, the odds ratio for hypertension, comparing the highest category of AHI (> or = 30 per hour) with the lowest category (< 1.5 per hour), was 1.37 (95% confidence interval [CI], 1.03-1.83; P for trend = .005). The corresponding estimate comparing the highest and lowest categories of percentage of sleep time below 90% oxygen saturation (> or = 12% vs < 0.05%) was 1.46 (95% CI, 1.12-1.88; P for trend <.001). In stratified analyses, associations of hypertension with either measure of SDB were seen in both sexes, older and younger ages, all ethnic groups, and among normal-weight and overweight individuals. Weaker and nonsignificant associations were observed for the arousal index or self-reported history of habitual snoring. CONCLUSION: Our findings from the largest cross-sectional study to date indicate that SDB is associated with systemic hypertension in middle-aged and older individuals of different sexes and ethnic backgrounds.

Adult↗
PubMed1999

Long-term ambient ozone concentration and the incidence of asthma in nonsmoking adults: the AHSMOG Study.

We conducted a prospective study of a cohort of 3091 nonsmokers, ages 27 to 87 years, to evaluate the association between long-term ambient ozone exposure and development of adult-onset asthma. Over a 15-year period, 3.2% of males and 4.3% of females reported new doctor diagnoses of asthma. For males, we observed a significant relationship between report of doctor diagnosis of asthma and 20-year mean 8-h average ambient ozone concentration (relative risk (RR)=2.09 for a 27 ppb increase in ozone concentration, 95% CI=1.03 to 4.16). We observed no such relationship for females. Other variables significantly related to development of asthma were a history of ever-smoking for males (RR=2.37, 95% CI=1.13 to 4.81), and for females, number of years worked with a smoker (RR=1.21 for a 7-year increment, 95% CI=1.04 to 1.39), age (RR=0.61 for a 16-year increment, 95% CI=0.44 to 0.84), and a history of childhood pneumonia or bronchitis (RR=2.96, 95% CI=1.68 to 5.03). Addition of other pollutants (PM10, SO4, NO2, and SO2) to the models did not diminish the relationship between ozone and asthma for males. These data suggest that long-term exposure to ambient ozone is associated with development of asthma in adult males.

Adult↗
PubMed1999

Predictors of longitudinal change in diffusing capacity over 8 years.

Low single-breath diffusing capacity (DL(CO)) values are associated with anatomic emphysema, but the predictors of longitudinal change in DL(CO) over many years are unknown. Study subjects were adult participants in the longitudinal Tucson Epidemiology Study of Obstructive Lung Disease who had at least one DL(CO) measurement during either of two surveys 8 yr apart (n = 543). Smoking status was determined at each examination (current, former, or never smoker). Quitters were defined as those currently smoking at the baseline DL(CO) examination (1982-1983) and self-reported as no longer smoking at the follow-up exam (1990-1991). The longitudinal DL(CO) data were analyzed using repeated measures analysis; because of missing observations this was done using a saturated random effects model. The results showed that males had higher levels of DL(CO) than females, current smokers had significantly lower levels of DL(CO) than never smokers, but there was no difference in their mean slopes over time. Smoking history, assessed using pack-years of smoking, was associated with reduced DL(CO) levels, independent of whether current or ex-smokers. Males and females demonstrated equivalent rates of decline in DL(CO) that accelerated with increasing age, and mean DL(CO) declines were associated with declines in FEV(1) between surveys.

Adult↗
PubMed1999

Respiratory symptoms and pulmonary function in an elderly nonsmoking population.

OBJECTIVE: To examine risk factors for chronic airway disease (CAD) in elderly nonsmokers, as determined by pulmonary function tests (PFTs), and to correlate reported respiratory symptoms with PFT measures. DESIGN: An observational survey. SETTING: Several communities in California. MEASUREMENTS: Exposures and respiratory history were assessed by standardized questionnaire. PFTs were performed and prediction equations derived. RESULTS: Significant risk factors for obstruction on PFTs in multiple logistic regression included reported environmental tobacco smoke (ETS) exposure (relative risk [RR]=1.44), parental CAD or hay fever (RR=1.47), history of childhood respiratory illness (RR=2.15), increasing age, and male sex. The number of years of past smoking was of borderline significance (RR=1.29 for 10 years of smoking; p=0.06). The prevalence of obstruction on PFTs was 24.9% in those with definite symptomatic CAD, compared with 7.5% in those with no symptoms of CAD. The prevalence of obstruction was 36.0% among those with asthma and 70.6% among those with emphysema. Also, symptomatic CAD correlated with reduction in lung function by analysis of covariance. The mean percent predicted FEV1 adjusted for covariates was 90.6% in persons with definite symptoms of CAD, compared with 97.8% in those without it (p < 0.001). CONCLUSIONS: Age, sex, parental history, childhood respiratory illness, and reported ETS exposures were significant risk factors for obstruction on PFTs. Self-reported respiratory symptoms also correlated significantly with PFTs.

Adult↗
PubMed1999

Underdiagnosis and undertreatment of asthma in the elderly. Cardiovascular Health Study Research Group.

OBJECTIVE: To describe the clinical correlates of asthma in a community-based sample of elderly persons. PARTICIPANTS: A community sample of 4,581 persons > or = 65 years old from the Cardiovascular Health Study. MEASUREMENTS: Standardized respiratory, sleep, and quality-of-life (QOL) questions, a medication inventory, spirometry, and ambulatory peak flow. RESULTS: Four percent of the participants reported a current diagnosis of asthma (definite asthma), while another 4% reported at least one attack of wheezing accompanied by chest tightness or dyspnea during the previous 12 months (probable asthma). Smokers and those with congestive heart failure were excluded from the subsequent analyses, leaving 2,527 participants. Of those who had definite asthma, 40% were taking a sympathomimetic bronchodilator, 30% inhaled corticosteroids, 21% theophylline, and 18% oral corticosteroids; 39% were taking no asthma medications. The participants with definite or probable asthma were much more likely than the others to have a family history of asthma, childhood respiratory problems, a history of workplace exposures, dyspnea on exertion, hay fever, chronic bronchitis, nocturnal symptoms, and daytime sleepiness. They were also more likely to report poor general health, symptoms of depression, and limitation of activities of daily living. There was little difference in the morbidity and QOL of participants with recent asthma-like symptoms who had received the diagnosis of asthma versus those who had not. CONCLUSIONS: Asthma in elderly persons is associated with a lower QOL and considerable morbidity when compared with those who do not have asthma symptoms. Asthma is underdiagnosed in this group and is often associated with allergic triggers; inhaled corticosteroids are underutilized.

Age Factors↗
PubMed1998

Spirometric reference equations for older adults.

The objective of this study was to develop spirometric reference equations for healthy, never-smoking, older adults. It was designed as a cross-sectional observational study consisting of 1510 Seventh Day Adventists, ages 43-79 years enrolled in a study of health effects of air pollutants. Individuals were excluded from the reference group (n = 565) for a history of current respiratory illness, smoking, or chronic respiratory disease, and for a number of 'non-respiratory' conditions which were observed in these data to be related to lower values of FEV1. Gender-specific reference equations were developed for the entire reference group and for a subset above 65 years of age (n = 312). Controlling for height and age, lung function was found to be positively related to the difference between armspan and height, and in males was found to be quadratically related to age. The predicted values for this population generally fell within the range of those of other population groups containing large numbers of adults over the age of 65 years. Individuals with lung function below the 5th percentile in this sample, however, could not be reliably identified by using the lower limits of normal predictions commonly used in North America and Europe.

Adult↗
PubMed1998

Long-term particulate and other air pollutants and lung function in nonsmokers.

The associations between lung function measures (spirometry and peak expiratory flow lability) and estimated 20-yr ambient concentrations of respirable particles, suspended sulfates, sulfur dioxide, ozone, and indoor particles were studied in a sample of 1,391 nonsmokers followed since 1977. Differences in air pollutants across the population were associated with decrements of lung function. An increase of 54 d/yr when particles < 10 micro(m) in diameter (PM10) exceeded 100 microg/m3 was associated with a 7.2% decrement in FEV1, as percent of predicted, in males whose parents had asthma, bronchitis, emphysema, or hay fever and with increased peak expiratory flow lability of 0.8% for all females and 0.6% for all males. An increase in mean SO4 concentration of 1.6 microg/m3 was associated with a 1.5% decrement in FEV1, as percent of predicted, in all males. An increase of 23 ppb of ozone as an 8-h average was associated with a 6.3% decrement in FEV1, as percent of predicted, in males whose parents had asthma, bronchitis, emphysema, or hay fever.

Adult↗
PubMed1997

The association of respiratory problems in a community sample with self-reported chemical intolerance.

This epidemiological study evaluated respiratory histories in those individuals reporting chemical intolerance (CI) in a community population sample. The subsample of 181 completed standard Respiratory Health Questionnaires. CI was determined from self-ratings of feeling 'moderately' to 'severely' ill from exposure to at least three of five common chemicals (paint, pesticides, car exhaust, new carpet, and perfume); the prevalence rate was 22.7%. The comparison group (CN) (31.5% of the sample) were selected from their reports of 'never' feeling ill from the same chemicals. The prevalence rate of CI in females was over twice that in males (28% vs 12.9%), a significant difference. There were no significant differences in smoking, age, or education between CI and CN. Prevalence rates for symptoms and Relative Risk Ratios (RR) indicated that the CI were significantly more likely to report chronic cough, phlegm, wheeze, chest tightness, exertional dyspnea, acute respiratory illnesses, hay fever, child respiratory trouble, and physician confirmed asthma. Several of these respiratory symptoms were significantly, though differentially, related to 'current' asthma and hay fever reports. Results suggest a potential vulnerability to and greater interference from respiratory illness for the CI, which have implications for women's health and quality of life.

Adolescent↗
PubMed1997

Peak flow lability: association with asthma and spirometry in an older cohort.

OBJECTIVE: To determine the success rate and correlates of ambulatory peak expiratory flow (PEF) monitoring in an epidemiologic study. DESIGN: An observational survey. SETTING: Several communities in California. PARTICIPANTS: We studied 1,223 nonsmoking men and women (mean age, 66 years) from an established cohort. OUTCOME MEASURES: A standard respiratory symptoms and diagnoses questionnaire, spirometry before and after bronchodilator, and a diary of PEF recorded four times per day for 7 days at home. RESULTS: A physician diagnosis of asthma was reported in 8.6% of the women and 9.4% of the men. Of those who agreed to complete PEF diaries at home, 87% successfully provided a valid measure of PEF lability. The mean PEF lability from those with asthma was significantly higher than the others (12.0% vs 8.9% in women and 10.2% vs 8.1% in men). Independent correlates of higher PEF lability included asthma, wheezing symptoms, airways obstruction by spirometry, older age, and male gender. CONCLUSIONS: Middle-aged and elderly persons are largely successful at providing a measure of PEF lability at home. In nonsmoking adults living in California, increased PEF lability is correlated with asthma, wheezing, airways obstruction, and older age, validating its use in epidemiology studies as an index of airways hyperreactivity.

Adult↗
PubMed1997

Peak expiratory flow from maximum expiratory flow volume curves in a community population: cross-sectional and longitudinal analyses.

The data from a longitudinal population study in Tucson, Arizona, were used to describe the development and decline with age of the peak expiratory flows (PEF) from maximum expiratory flow-volume (MEFV) curves derived using a computer-linked pneumotachometer. Subjects had performed at least one technically acceptable MEFV test in 9 of the first 11 surveys (1972-1989). There were 2,724 subjects with adequate MEFV curves, and thus PEF, in the first survey, but only 1315 in the 11th survey. The subjects were stratified based on responses to questionnaires into nonsmoking healthy subjects and others. The PEF were analysed cross-sectionally and longitudinally using data from the 6th-11th surveys (1979-1989). For longitudinal analysis, the reference population had 397 males with 1,153 observations, and 534 females with 1,700 observations. The resulting equations were compared, evaluating differences between the longitudinal and cross-sectional equations, and between reference and nonreference longitudinal populations. The results show that there were effort-dependent effects in absolute values of PEF, even after editing. Nevertheless, as with most MEFV measures in reference populations, PEF had an early increase in the rate of development, followed by a plateau phase, followed by a constant rate of decline. The ages at which changes in growth rates of PEF occurred differed by gender. The longitudinal data in adults showed a less steep decline with age compared to the cross-sectional data, as found previously for the other MEFV variables. Males in the nonreference group did not reach the same maximum level and had a steeper decline throughout adult life than did males in the reference group; females were similar. Asthmatics of both genders had slightly greater declines compared to the other nonreference subjects.

Adolescent↗
PubMed1997

Diurnal variation of PEF and its use in epidemiological studies.

Diurnal variability in peak expiratory flow (PEF) has been an accepted clinical method in the management of asthma and the evaluation of occupational asthma. In this paper, the basis for this usage together with other clinical and epidemiological applications is discussed. The measured characteristics of PEF diurnal variability are described in asthmatics and asymptomatic subjects, showing the greater variability in asthmatics, and the "morning dip" related to circadian rhythm. PEF measured by pneumotachograph and the mini-Wright meter are shown to be in good agreement, but PEF measured by the latter and other small PEF meters is different in terms of absolute values, and both intraindividual variability within test sets and diurnally. The use of PEF meters, and the daily diaries in which the subject or patient records PEF and related factors are described.

Adolescent↗
PubMed1996

Early childhood respiratory symptoms and the subsequent diagnosis of asthma.

BACKGROUND: Respiratory symptoms are frequent in very young children, and the relation of these symptoms to later asthma in some of these children is unknown. OBJECTIVE: The aim of the study was to describe the natural history of respiratory symptoms in a community-based sample of young children who were prospectively observed for as long as 11 years. METHODS: Subjects were participants in the Tucson Epidemiologic Study of Airways Obstructive Disease. They were under 5 years of age at enrollment and were studied by means of a parent-administered mail survey instrument every 1 to 2 years for 3 to 11 years. RESULTS: Among subjects younger than 1 year of age, no single respiratory symptom, such as cough or wheeze only with colds, significantly increased the risk of a subsequent diagnosis of asthma. Among 1- and 2-year-olds, however, those with wheeze only with colds and those with attacks of shortness of breath with wheeze were more likely to be diagnosed with asthma later when compared with children without those symptoms (odds ration = 2.1; p < 0.05 for wheeze only with colds). At ages 3 to 4 years, symptoms were even more strongly associated with subsequent asthma (odds ratio = 7.2; p < 0.0001 for attacks of shortness of breath with wheeze). CONCLUSION: Although respiratory symptoms reported by parents very early in life are not significantly associated with future asthma, those symptoms that begin at or persist through ages 3 to 4 years are.

Adolescent↗
PubMed1996

Epidemiological studies of the respiratory effects of air pollution.

Environmental epidemiological studies of the health effects of air pollution have been major contributors to the understanding of such effects. The chronic effects of atmospheric pollutants have been studied, but, except for the known respiratory effects of particulate matter (PM), they have not been studied conclusively. There are ongoing studies of the chronic effects of certain pollutant classes, such as ozone, acid rain, airborne toxics, and the chemical form of PM (including diesel exhaust). Acute effects on humans due to outdoor and indoor exposures to several gases/fumes and PM have been demonstrated in epidemiological studies. However, the effects of these environmental factors on susceptible individuals are not known conclusively. These acute effects are especially important because they increase the human burden of minor illnesses, increase disability, and are thought to decrease productivity. They may be related to the increased likelihood of chronic disease as well. Further research is needed in this latter area, to determine the contributions of the time-related activities of individuals in different microenvironments (outdoors, in homes, in transit). Key elements of further studies are the assessment of total exposure to the different pollutants (occurring from indoor and outdoor source) and the interactive effects of pollutants. Major research areas include determination of the contributions of indoor sources and of vehicle emissions to total exposure, how to measure such exposures, and how to measure human susceptibility and responses (including those at the cellular and molecular level). Biomarkers of exposures, doses and responses, including immunochemicals, biochemicals and deoxyribonucleic acid (DNA) adducts, are beginning to promote some basic knowledge of exposure-response, especially the mechanisms. These will be extremely useful additions to standard physiological, immunological, and clinical instruments, and the understanding of biological plausibility. The outcomes of all this work will be the management of risks and the prevention of respiratory diseases related to air pollution.

Air Pollutants↗