Salivary cotinine levels in children with otolaryngological disorders

To determine if salivary cotinine, a biomarker for tobacco smoke exposure, is elevated more often or to a higher degree in children meeting criteria for tonsillectomy or tympanostomy tube insertion.

Saliva samples were obtained from 3 groups of children for salivary cotinine measurement. Group 1 served as healthy controls. Group 2 consisted of subjects meeting tympanostomy tube criteria. Group 3 consisted of patients meeting tonsillectomy criteria. Environmental tobacco smoke (ETS) exposure was defined as a salivary cotinine concentration ≥1.0 ng/mL. Demographic data, smoke exposure history, and co-morbidities were also determined.

331 patients were included, with 112 in Group 1, 111 in Group 2, and 108 in Group 3. No differences were encountered for smoke exposure by history or smoker's identity, salivary cotinine level, or frequency of positive cotinine results. 42.6% of Group 1 had positive salivary cotinine compared to 51.8% of Group 2 and 47.7% of Group 3. Group 1 had a mean salivary cotinine level of 2.42 ng/mL compared to 2.54 ng/mL in Group 2 and 2.60 ng/mL in Group 3. The frequency of positive cotinine levels was higher than expected based on parental history. Among subjects with positive cotinine levels, 93 had no ETS exposure, and 64 had ETS exposure by history.

Approximately 50% of children who undergo tonsillectomy and tympanostomy tube insertion have objective evidence of ETS exposure. Parental history underestimates passive smoke exposure, which can impact perioperative care.