Tuesday, July 19, 2011 (Last Updated: 07/20/2011)
TUESDAY, July 19 (HealthDay News) -- Exposure to secondhand smoke (SHS) is associated with an increased prevalence of low-frequency sensorineural hearing loss (SNHL) and elevated pure-tone hearing thresholds in adolescents, according to a study published in the July issue of the Archives of Otolaryngology -- Head & Neck Surgery.
Anil K. Lalwani, M.D., from the New York University Langone Medical Center, and colleagues investigated the association between SHS exposure and SNHL in adolescents. Data from 1,533 individuals, aged 12 to 19 years, were taken from the National Health and Nutrition Examination Survey (2005 to 2006). These individuals underwent audiometric testing, had serum cotinine levels available, and were not active smokers. The major outcome measure was SNHL, defined as an average pure-tone level greater than 15 dB for 0.5, 1, and 2 kHz (low frequency) and 3, 4, 6, and 8 kHz (high frequency).
The investigators found that, based on multivariate analysis, exposure to SHS, as measured by serum cotinine levels, was correlated with elevated pure-tone hearing thresholds at 2, 3, and 4 kHz, a significantly higher rate of unilateral low-frequency SNHL and a 1.83-fold increased risk of unilateral low frequency SNHL. Serum cotinine levels reveal a direct relationship between the prevalence of SNHL and the level of SHS exposure. Hearing difficulties were not recognized by almost 82 percent of adolescents with SNHL.
"SHS is associated with elevated pure-tone thresholds and an increased prevalence of low-frequency SNHL that is directly related to level of exposure, and most affected individuals are unaware of the hearing loss," the authors write.
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