Secondhand smoke alters arachidonic acid metabolism in infants and children with cystic fibrosis

Children ages 0-10 years old with CF were recruited from 2012-2015 at the outpatient CF clinic, and classified according to age (infants <1 year old, vs. children 1-10 years old). The diagnosis of CF was defined as two disease-causing mutations or a sweat chloride test ≥ 60 mmol/L. Hair and blood samples were collected from each subject. Hair nicotine concentrations were determined and considered as the primary objective measure of SHSe. Hair nicotine provides a long-term measure of SHSe as nicotine is integrated into the growing hair shaft over multiple months. (15) For each subject, 30-40 shafts of hair of approximately 2-3 cm in length were cut at the hair root from the occipital skull. Hair samples were refrigerated at 4° for storage, washed before analyses to remove ambient nicotine (15) and batch-tested at a contract research facility (Environmental Health Sciences, Johns Hopkins School of Public Health). Samples were processed by reverse-phase high-performance liquid chromatography with electrochemical detection as described. (15) Hair nicotine concentrations were expressed as ng/mg of hair and the assay limit of detection was 0.087 ng/mg. 40 total samples: 12 healthy, 28 cycstic fibrosis (CF); Of the CF samples, 10 were negative for nicotine as tested by hair sample and 18 were positive