Abigail Whitehouse

Asthma control in London secondary school children

ABSTRACT Objective: The asthma control test (ACT) is a validated tool for assessing control in asthmatic children aged 12 years and older. Using the ACT, we sought to assess asthma control and knowledge in London secondary school children. Methods: Secondary schools in London, UK, participated in this study. Children with doctor-diagnosed asthma were invited to complete an online questionnaire that included the ACT and questions about asthma. Suboptimal asthma control was defined as an ACT score of ≤ 19 out of a maximum score of 25. Data are summarised as median and interquartile range (IQR), and were analysed by either Mann-Whitney test, or chi-square test. A p value of < 0.05 was considered significant. Results: A total of 799 children completed the questionnaire; 689 (86.2%) were included for analysis. Suboptimal asthma control was reported by 49.6% of students. Over a third (42.4%) of students prescribed a short-acting β2-agonist inhaler felt uncomfortable using it at school, and 29.2% (n = 173) reported not using this inhaler when wheezy. 56.4% (n = 220) of those with regular inhaled corticosteroids did not take them as prescribed, and 41.7% did not know what this inhaler was for. Suboptimal control was associated with a greater proportion of students reporting that they were ‘somewhat’, ‘hardly’ or ‘not at all’ comfortable using inhalers at school (52.7% vs 29.1%, p < 0.01) and outside school (22.8% vs. 14.8%, p < 0.01). Conclusions: Suboptimal asthma control and poor asthma knowledge are common in London schoolchildren.

Use of cleaner-burning biomass stoves and airway macrophage black carbon in Malawian women

Exposure to particulate matter (PM) from burning of biomass for cooking is associated with adverse health effects. It is unknown whether or not cleaner burning biomass-fuelled cookstoves reduce the amount of PM inhaled by women compared with traditional open fires. We sought to assess whether airway macrophage black carbon (AMBC) - a marker of inhaled dose of carbonaceous PM from biomass and fossil fuel combustion - is lower in Malawian women using a cleaner burning biomass-fuelled cookstove compared with those using open fires for cooking. AMBC was assessed in induced sputum samples using image analysis and personal exposure to carbon monoxide (CO) and PM were measured using Aprovecho Indoor Air Pollution meters. A fossil-fuel exposed group of UK women was also studied. Induced sputum samples were obtained from 57 women from which AMBC was determined in 31. Median AMBC was 6.87 μm2 (IQR 4.47–18.5) and 4.37 μm2 (IQR 2.57–7.38) in the open fire (n = 11) and cleaner burning cookstove groups (n = 20), respectively (p = 0.028). There was no difference in personal exposure to CO and PM between the two groups. UK women (n = 5) had lower AMBC (median 0.89 μm2, IQR 0.56–1.13) compared with both Malawi women using traditional cookstoves (p < 0.001) and those using cleaner cookstoves (p = 0.022). We conclude that use of a cleaner burning biomass-fuelled cookstove reduces inhaled PM dose in a way that is not necessarily reflected by personal exposure monitoring.

Urinary prostanoids in preschool wheeze

Acute episodes of wheeze in children of preschool age are frequently triggered by viral upper respiratory tract infections and result in a significant burden to health services [1]. However, to date, the inflammatory mechanisms underlying preschool wheeze remain unclear. Mediators that have not been studied in preschool wheeze, but are implicated in the pathogenesis of wheeze in adults with asthma, include the pro-inflammatory prostanoid prostaglandin D2 (PGD2) [2] and the anti-inflammatory prostanoid PGE2 [3, 4]. In this study, we sought evidence for either increased PGD2 biosynthesis or reduced PGE2 biosynthesis, or a combination of both in children with preschool wheeze. To achieve this, we measured the major metabolites of PGD2 and PGE2 in the urine: 9α-hydroxy-11,15-dioxo-2,3,4,5-tetranor-prostan-1,20-dioic acid (tetranor-PGDM) and 9,15-dioxo-11α-hydroxy-13,14-dihydro-2,3,4,5-tetranor-prostan-1,20-dioic acid (tetranor-PGEM), respectively [5, 6]. Tetranor PGDM, a urinary metabolite of prostaglandin D2, is increased in children with preschool wheeze http://ow.ly/Ynjy305ZY9L

Carbonaceous particulate matter on the lung surface from adults living in São Paulo, Brazil.

Accumulation of carbonaceous particulate matter (PM) in the lung is associated with chronic disease. The amount of carbonaceous PM in airway macrophages is reported to be associated with exposure to both fossil fuel PM and cigarette smoke. However, the contribution of these exposures to carbonaceous PM at the lung surface is unclear. Objectives We therefore sought to identify the exposures associated with lung surface in long-term residents of São Paulo, Brazil. Methods Lung surface carbon were analyzed in 72 autopsy specimens by image analysis. Smoking history, measured PM10 nearest to the home, distance to main road, and distance-weighted traffic density were used as exposure variables. Data are summarized as median (IQR), and compared by Mann Whitney Test, with correlations done by Spearman’s correlation. Results There was no association between lung surface and age or gender. There was no statistically significant association in lung surface between smokers and non-smokers 6.74 cm2 (3.47 to 10.02) versus 5.20cm2 (2.29 to 7.54), and there was no significant association between lung surface carbon and exposure to environmental PM and markers of traffic exposure. Conclusion We did not find a statistically significant association between lung surface and smokers and non-smokers, and no statistically significant association between lung surface carbon and environmental exposure variables. These results suggest that lung surface carbon in long-term residents of São Paulo may predominately be from environmental PM, but the most appropriate environmental exposure marker remains unclear.