Asthma: Clinical Features

Seaton, Anthony; Crompton, G.K.

doi:10.1002/9780470695999.ch34

Cited by 10 publications

(8 citation statements)

References 481 publications

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“…We also observed that a reduction in FEF 25−75 was associated with the cumulative pesticide exposure index (Table 6), used as an estimate of long-term exposure, and with the occurrence of respiratory symptoms (Table 4), which is in accordance with previous studies (Newton & Breslin, 1983;Salameh et al, 2005). This finding supports the notion that continuous exposure to pesticides may affect small airways, leading to peripheral airway obstruction, as FEF 25−75 is believed to be a more sensitive index of airway obstruction than the FEV1, especially in the small airways (Seaton & Crompton, 2000). Since a fall in FEF 25−75 in the context of an otherwise normal spirometry may indicate airway hyperresponsiveness, an asthma-like condition (Alberts et al, 1994), our finding raises the possibility that low levels of pesticide aerosols among greenhouses workers may cause a chronic inflammatory response in the small airways, with a higher possibility of long-term sequelae, particularly bronchial hyperresponsiveness (Agabiti et al, 2001;Salome et al, 2000;Lein & Fryer, 2005).…”

Section: Discussionsupporting

confidence: 81%

Low Level of Exposure to Pesticides Leads to Lung Dysfunction in Occupationally Exposed Subjects

Hernández

Casado²,

Pena

et al. 2008

Inhalation Toxicology

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Pesticides may contribute to adverse respiratory health effects among farmers and have been considered one causal factor for the rise in asthma prevalence. This cross-sectional study was conducted to evaluate potential respiratory function abnormalities following long-term pesticide exposure by means of a complete pulmonary function testing, including spirometry, lung volumes, and diffusing capacity for carbon monoxide. The study population was comprised by workers from a prominent intensive agriculture area of southern Spain that relied on pesticides for the control of plagues. Eighty-nine pesticide sprayers of plastic greenhouse farming and a control group of 25 nonspraying control farmers from the same area were interviewed by a general practitioner asking about sociodemographic factors, occupational exposure, and clinical symptoms by using a structured questionnaire. Multiple regression analyses showed a relationship of short-term exposure to pesticides (as indicated by a drop in serum cholinesterase >25% of baseline levels) with reduced forced expired volume in 1 s, and of long-term exposure (as indicated by a cumulative pesticide exposure index) with reduced forced expiratory flow rate. Exposure to bipyridilium-class herbicides was a determinant of a fall in the diffusing capacity of the lungs, and neonicotinoid insecticides showed a relationship with lower pulmonary volumes (total lung capacity, residual volume, and functional residual capacity), suggestive of restrictive lung disease, and with an increased risk of reporting irritative symptoms.

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Section: Discussionsupporting

confidence: 81%

Low Level of Exposure to Pesticides Leads to Lung Dysfunction in Occupationally Exposed Subjects

Hernández

Casado²,

Pena

et al. 2008

Inhalation Toxicology

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“…The inflammation may lead to irreversible obstruction to airflow. Asthma results from the interaction of many genetic and environmental factors which influence the tone or reactivity of the airways, the response varies from individual to individual and from time to time [11]. Vitamin D deficiency is linked to an array of immunologically based diseases focusing on asthma.…”

Section: Discussionmentioning

confidence: 99%

Assessment of Serum Vitamin D in Patients with Bronchial Asthma

Aaty

Aziz

Habashy

et al. 2015

Egyptian Journal of Chest Diseases and Tuberculosis

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Background: Asthma is one of the most common chronic diseases worldwide and has been increasing in prevalence over the last few decades; its exact cause remains unknown and likely has its origin in complex interactions among multiple genetic and environmental factors. The World Health Organization (WHO) stated that approximately 300 million people have asthma. Recently the effects of vitamin D as a hormone have gained attention. Vitamin D appears to have regulatory effects on every part of the immune system, vitamin D deficiency being linked to an array of immunologically based diseases focusing on asthma. So the assessment of serum vitamin D in patients with bronchial asthma is useful.Objective: The aim of this study is to assess the level of serum vitamin D in patients with bronchial asthma.Methods: The present study, included 50 subjects, 40 patients diagnosed as bronchial asthma and 10 healthy volunteers. The asthmatic patient group was divided into group (A) asthma in between attack and group (B) exacerbated asthma, that was divided into subgroups (I), (II) and (III) mild, moderate and severe exacerbated asthma, respectively according to severity of symptoms and FEV1. Results: Serum vitamin D level was highly significantly lower in the asthmatic patient group compared to the control subject group and lowest serum 25 hydroxy(OH) vitamin D value in the severely exacerbated asthma group. There was a positive correlation between decreased serum 25 (OH)D levels and decreased FEV1.Conclusions: Vitamin D deficiency was highly prevalent in asthmatic patients, there was a strong correlation between asthma severity and 25(OH) vitamin D concentrations and there was a direct * Corresponding author. Address: and a positive significant correlation between vitamin D levels and pulmonary function tests in asthmatic patients, so the measurement of serum vitamin D levels in patients with bronchial asthma is very useful.

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“…FEF 25%–75%, is a sensitive indicator of obstruction in small airways of the lungs31 underlining distal airflow limitation with pesticide exposure. Similar to previous studies in LSOFs in Ethiopia19 20 we showed a significant reduction in FEV 1 in pesticide exposed as compared with unexposed controls.…”

Section: Discussionmentioning

confidence: 99%

Occupational pesticide exposure and respiratory health: a large-scale cross-sectional study in three commercial farming systems in Ethiopia

Negatu

Kromhout

Mekonnen

et al. 2016

Thorax

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Rationale In the last decade, due to expansion of greenhouses and irrigated farms, the use of pesticides in Ethiopia has increased 6-13-fold leading to potential health risks. Objective To investigate if occupational exposure to pesticides is associated with respiratory health effects in farmers and farm workers from commercial farming systems. Methods We performed two cross-sectional surveys comprising different farming systems. In the first survey we studied respiratory symptoms among 1104 subjects of which 601 were occupationally exposed to pesticides (ie, 256 pesticide applicators, 345 re-entry workers) and 503 unexposed individuals. The second survey, carried out 2 years later in the same farming regions, additionally included lung function measurement and comprised a total of 387 study subjects of which 206 were occupationally exposed to pesticides (142 applicators and 64 re-entry workers) and 180 unexposed individuals. Results We observed increased risks for chronic cough and shortness of breath (OR=3.15, 95% CI 1.56 to 6.36 and OR=6.67, 95% CI 2.60 to 17.58) among the exposed subjects as compared with unexposed individuals in the first survey. These results were corroborated in the second survey where we also observed reductions in FEV 1 (140 mL), forced expiratory flow 25%-75% (550 mL/s) and risk of FEV 1 /FVC ratio <0.8 (OR=4.31, 95% CI 2.11 to 8.81) among pesticide exposed workers. Conclusions These findings indicate an increased risk of adverse respiratory health among workers exposed to pesticides. As those effects occurred in young workers (mean age 27 years) and within a relative short duration of exposure (4 years) implementation of stringent occupational health measures are warranted.

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Asthma: Clinical Features

Cited by 10 publications

References 481 publications

Low Level of Exposure to Pesticides Leads to Lung Dysfunction in Occupationally Exposed Subjects

Low Level of Exposure to Pesticides Leads to Lung Dysfunction in Occupationally Exposed Subjects

Assessment of Serum Vitamin D in Patients with Bronchial Asthma

Occupational pesticide exposure and respiratory health: a large-scale cross-sectional study in three commercial farming systems in Ethiopia

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