Biomedical subjects

H M Boezen

Publications and source records attributed to H M Boezen.

24 records · Page 2Linked to original sources

PubMed1999

Acute effects of urban air pollution on respiratory health of children with and without chronic respiratory symptoms.

OBJECTIVES: To investigate to what extent different components of air pollution are associated with acute respiratory health effects in children with and without chronic respiratory symptoms. METHODS: During three consecutive winters starting in 1992-3, peak expiratory flow (PEF) and respiratory symptoms were registered daily in panels of children of 7-11 years old with and without symptoms, living in urban areas with high traffic intensity in The Netherlands. Simultaneously, panels of children living in non-urban areas were studied. Daily measurements of particles with aerodynamic diameter < 10 microns (PM10), black smoke (BS), sulphate, SO2, and NO2 were performed in both areas. RESULTS: The contrast in particle concentrations (PM10, BS, and sulphate) between urban and non-urban areas was small, but there was more contrast in the concentrations of SO2 and NO2. In children with symptoms from both areas, significant associations were found between PM10, BS, and sulphate concentrations and the prevalence of symptoms of the lower respiratory tract (LRS) and decrements in PEF. Particle concentrations were also associated with use of bronchodilators in the urban areas, but not in the non-urban areas. After stratification by use of medication, stronger associations were found in children who used medication than in children who did not use medication. The magnitude of the estimated effects was in the order of a twofold increase in the use of bronchodilators, a 50% increase in LRS, and an 80% increase in decrements in PEF for a 100 micrograms/m3 increase in the 5 day mean PM10 concentration. In children without symptoms, significant associations were found between concentrations of PM10 and BS and decrements in PEF in both areas, but these associations were smaller than those for children with symptoms. No associations with respiratory symptoms were found. CONCLUSIONS: The results suggest that children with symptoms are more susceptible to the effects of particulate air pollution than children without symptoms, and that use of medication for asthma does not prevent the adverse effects of particulate air pollution in children with symptoms.

Air Pollution↗

PubMed1999

Modulation of the acute respiratory effects of winter air pollution by serum and dietary antioxidants: a panel study.

This study investigated whether a high dietary intake or serum concentration of antioxidant (pro-) vitamins could attenuate the acute respiratory effects of air pollution in panels of adults (n = 227) aged 50-70 yrs with chronic respiratory symptoms in two winters starting in 1993/1994. Subjects performed daily peak expiratory flow (PEF) measurements in the morning and evening and reported the occurrence of respiratory symptoms in two regions (urban and nonurban) each winter. Logistic regression analysis was used with the prevalences of large PEF decrements as dependent variables and air pollution levels as independent variables. Analyses were performed separately for subjects below and above the median levels of serum beta-carotene and the intake of dietary vitamin C and beta-carotene. Subjects with low levels of serum beta-carotene more often had large PEF decrements when particles <10 microm in diameter or black smoke levels which were higher compared to subjects with high levels of serum beta-carotene. The same results tended to be observed for dietary vitamin C or beta-carotene, but there were less significant air pollution effects in the low dietary antioxidant group. The results suggest that serum beta-carotene and to a lesser extent dietary vitamin C and beta-carotene may attenuate peak expiratory flow decrements due to air pollution in subjects with chronic respiratory symptoms.

Aged↗

PubMed1998

Breathlessness in elderly individuals is related to low lung function and reversibility of airway obstruction.

The perception of breathlessness is a subject-related factor which is linked to respiratory disease, cardiac disease and overweight. We studied the distribution of breathlessness, its association with respiratory disease, cardiac disease and overweight, as well as its association with lung function, reversibility of airway obstruction ("reversibility") and peak expiratory flow (PEF) variability in an elderly population. Data on breathlessness (rated with Borg scale), lung function, reversibility, PEF variability, respiratory symptoms, cardiac disease and overweight were collected in a random sample of 210 elderly (>55 yrs old) who participated in a physical fitness test. Individuals with a Borg score >0 were taken to have breathlessness. Subjects with a Borg score >0 (n=50, 24%) were three to five times more likely to have a low lung function and large reversibility than subjects with a Borg score of zero, independent of the presence of respiratory symptoms, cardiac disease or overweight, although these three factors were all associated with low lung function and a large reversibility and PEF variability. Reversibility was not associated with PEF variability whatsoever. In elderly individuals, breathlessness is frequently present. Assessment of breathlessness using the Borg-scale seems an important clinical measurement, because it is an important independent predictor of lung function impairment in the elderly.

Age Distribution↗

PubMed1996

PEF variability, bronchial responsiveness and their relation to allergy markers in a random population (20-70 yr).

We investigated the coherence of bronchial hyperresponsiveness (BHR) and peak expiratory flow (PEF) variability in their relation to allergy markers and respiratory symptoms in 399 subjects (20-70 yr). Bronchial hyperresponsiveness to methacholine was defined by both the provocative dose causing a fall in FEV1 of 20%, and the dose-response slope. PEF variability was determined as diurnal PEF variation (amplitude percent mean) and between-day PEF variation. Skin tests positivity, serum total IgE, and specific IgE (RAST) for house-dust mite (HDM), cat, timothy grass, and birch ("pollen") were determined, as well as the number of peripheral blood eosinophils. Wheeze and nocturnal dyspnea were defined as asthma-like symptoms; dyspnea > or = grade 3, cough and phlegm as chronic obstructive pulmonary disease (COPD)-like symptoms. The reciprocal of the dose-response slope and PEF variability were significantly correlated (r = -0.39). Subjects with a positive skin test for HDM (odds ratio [OR] = 3.9), cat (OR = 8.3), or pollen (OR = 3.6), or specific IgE for HDM (OR = 2.3), cat (OR = 3.4), or pollen (OR = 1.9) had increased risk of BHR compared with the reference group (all p values < 0.05). Higher levels of serum total IgE were significantly associated with higher odds for BHR (OR = 2.5 per log unit). There was no significant association between skin test positivity, serum total IgE, or presence of specific IgE and PEF variability. Neither BHR nor PEF variability were associated with higher numbers of peripheral blood eosinophils. There are different associations of BHR and PEF variability with allergy markers. Although BHR and PEF variability are significantly correlated, they cannot be used interchangeably in epidemiologic settings.

Adult↗

PubMed1995

Relation between respiratory symptoms, pulmonary function and peak flow variability in adults.

BACKGROUND: A study was carried out to determine whether subjects with respiratory symptoms are more likely to have impaired lung function or increased airway lability, and to quantify these relationships in a population of adults. METHODS: Data were collected from 511 participants (aged 20-70 years) from the Dutch part of the European Community Respiratory Health Survey (ECRHS). The symptoms analysed were: wheeze, dyspnoea > or = grade 3, nocturnal dyspnoea, cough and phlegm, and history of allergy. Lung function was measured by peak expiratory flow (PEF) and forced expiratory volume in one second (FEV1). PEF variability was used as an index for bronchial lability. RESULTS: Both FEV1 and PEF were decreased with increasing numbers of symptoms. Subjects with one symptom had an increased risk of having an FEV1 value of < 70% (OR = 4.2) and this risk increased with an increasing number of symptoms. Subjects with three or more symptoms had an increased risk of having a PEF value of < 70%, a diurnal variation in PEF of > 10% (both OR = 4.4), and an increased risk of high between day variation (OR = 6.6). CONCLUSIONS: Subject-reported symptoms are related to impaired lung function and to increased variability of peak flow.

Adult↗

PubMed1994

Distribution of peak expiratory flow variability by age, gender and smoking habits in a random population sample aged 20-70 yrs.

Peak expiratory flow (PEF) variability can be considered as an index of bronchial lability. Population studies on PEF variability are few. The purpose of the current paper is to describe the distribution of PEF variability in a random population sample of adults with a wide age range (20-70 yrs), and to assess relationships to age, gender and smoking habits. PEF data were collected in 511 participants of the Dutch part of the European Community Respiratory Health Survey. A training effect was found, absolute PEF values on the first measurement day being significantly lower. Females had greater PEF variability (adjusted for age, height and pack-years) and lower absolute PEFs than males. The mean within-day variation (amplitude % mean) was 3.66% (SD 2.03%), whereas the mean day-to-day variation was relatively small: 0.08% (SD 1.53%). Absolute PEFs were lower and amplitude % mean were significantly higher in older age groups. Smoking was significantly associated with lower mean PEFs and greater amplitude % mean. We observed lower mean values of the amplitude % mean than other investigators, possibly related to lower frequency of PEF recording (twice daily). We conclude that PEF and PEF variability have a normal or log-normal distribution. When studying PEF variability, age, gender and smoking habits should be taken into account.

Adult↗