Impact of Saharan dust exposure on airway inflammation in patients with ischemic heart disease

Abstract

Epidemiological studies found that increases in the concentrations of airborne particulate matter (PM) smaller than 10 microns diameter (PM10) in the ambient air due to desert dust outbreaks contribute to global burden of diseases, primarily as a result of increased risk of cardiovascular morbidity and mortality. No studies have investigated the possible association between desert dust inhalation and airway inflammation in patients with ischemic heart disease (IHD). Induced sputum was collected in 38 patients and analyzed to determine markers of airway inflammation (Transforming Growth Factor-β1 [TGF-β1] and hydroxyproline) concentrations. For the purpose of the investigation, PM10 and reactive gases concentrations measured in the European Air Quality Network implemented in the Canary Islands were also used. We identified Saharan desert dust using meteorology and dust models. Patients affected by smoking, chronic obstructive pulmonary disease (COPD), asthma, pulmonary abnormalities, acute bronchial or pulmonary disease were excluded. The median of age of patients was 64.71 years (56.35-71.54) and 14 (38.84%) of them were women. TGF-β1 and hydroxyproline in sputum were highly associated to PM10 inhalation from the Saharan desert. According to a regression model, an increase of 1 µg/m3 of PM10 concentrations due to desert dust, results in an increase of 3.84 pg/gwt of TGF-β1 (R2 adjusted = 89.69%) and of 0.80 μg/gwt of hydroxyproline (R2 adjusted = 85.28%) in the sputum of patients. The results of this study indicate that the exposure to high PM10 concentrations due to Saharan dust events are associated with intense inflammatory reaction in the airway mucosae of IHD-patients.