Serum Cotinine Is Associated With Tympanometric Abnormalities Suggestive of Middle-Ear Pressure Dysregulation in US Adults.

OBJECTIVE

To examine the association between serum cotinine and tympanometric abnormalities in US adults.

DESIGN

Cross-sectional study.

SETTING

National Health and Nutrition Examination Survey.

PARTICIPANTS

Adults aged 20 years or older with available data on serum cotinine and tympanometry.

MAIN OUTCOME MEASURES: The primary outcome was defined as a Type B or Type C tympanogram in either ear. Sensitivity analyses were performed for outcomes defined as a Type C tympanogram in either ear and a Type B tympanogram in either ear.

RESULTS

A total of 13 169 adults were included. In the fully adjusted model, higher serum cotinine was associated with higher odds of the primary tympanometric abnormality outcome. For each log2 increase in serum cotinine, the odds ratio (OR) was 1.024 (95% confidence interval [CI], 1.011-1.037; p < 0.001). Compared with the lowest quartile, the highest quartile had an OR of 1.295 (95% CI, 1.060-1.582; p = 0.011), with a significant trend across quartiles (p for trend = 0.009). In sensitivity analyses, the association was more evident for Type C tympanometric patterns (OR 1.570, 95% CI 1.259-1.957 for the highest vs. lowest quartile) than for Type B patterns, for which no significant association was observed (OR 0.652, 95% CI 0.406-1.048; p = 0.077).

CONCLUSIONS

Higher serum cotinine levels were associated with higher odds of tympanometric abnormalities in US adults. The association was more apparent for Type C than for Type B tympanometric patterns, suggesting that tobacco exposure may be more closely related to negative middle-ear pressure abnormalities than to nonspecific abnormal tympanograms.