By Nancy Walsh, MedPage Today, 7/18/11

Smoke gets in your ears — if you’re a teen exposed to secondhand smoke — and is associated with hearing loss, a large study suggested.

Exposed adolescents were 1.83 times more likely to experience low-frequency hearing loss (95% CI 1.08 to 3.41) than those who had no exposure, according to Anil K. Lalwani, MD, and colleagues from New York University in New York City.

And the greatest risk for hearing loss — a 2.72-fold increase (95% CI 1.46 to 5.06) — was in those with the highest levels of exposure as determined by serum cotinine levels, Lalwani’s group reported in the July Archives of Otolaryngology-Head & Neck Surgery.

The list of potentially harmful outcomes associated with exposure to secondhand smoke continues to grow, from low birth weight to behavioral and cognitive problems and respiratory tract infections — and more than half of U.S. children are exposed.

In the first study to examine secondhand smoke exposure and sensorineural hearing loss in young people, the investigators analyzed cross-sectional data from the 2005-2006 National Health and Nutrition Examination Survey (NHANES).

They identified 1,533 nonsmokers ages 12 to 19 who had undergone audiometric testing and whose serum cotinine levels had been measured.

Low-frequency sensorineural hearing loss was defined as a pure-tone level above 15 dB for 0.5, 1, and 2 kHz, while high-frequency loss was a level above 15 dB for 3, 4, 6, and 8 kHz.

Overall rates of hearing loss were:

• Unilateral low-frequency, 9.55%
• Bilateral low-frequency, 2.19%
• Unilateral high-frequency, 15.38%
• Bilateral high-frequency, 3.68%

Yet only 18.43% of the teens with these forms of hearing loss were aware of the problem.

Full story at http://www.medpagetoday.com/PrimaryCare/Smoking/27591