The effect of gas cooking on bronchial hyperresponsiveness and the role of immunoglobulin E

Some studies have shown an association between gas cooking and respiratory symptoms. This study investigated whether gas cooking affects bronchial responsiveness and whether particular subjects are more sensitive to this effect. Multiple linear regression analysis was performed with the dose-response slope (Percentage fall in forced expiratory volume in one second (FEV1) divided by total dose of methacholine given) as the dependent variable in 1,921 subjects from a random sample of the Dutch population, aged 20-70 yrs. Whether the association was different according to sex, age, total immunoglobulin (Ig)E, specific IgE to inhalant allergens or smoking habits was tested by including interaction terms into the regression model. Subjects who used gas for cooking had a higher prevalence of bronchial hyperresponsiveness (provocative dose causing a 20% fall in FEV1 (PD20) < or = 2 mg) than those who used electricity (21% versus 14%) and this was dependent on the presence of atopy. Especially subjects with total IgE levels in the highest quartile had a significantly higher dose-response slope when using gas for cooking. This was independent of the presence of specific IgE to inhalant allergens. These results show increased bronchial responsiveness with gas cooking, which was only found in subjects with high total immunoglobulin E levels. This suggests that atopic subjects are sensitive to adverse effects of gas cooking on respiratory health.