Obese adolescents have a higher risk of hearing loss compared to normal weight adolescents, an American study finds.

Detailed findings

In the study, females had a higher prevalence of overall notches than males (18.2% vs 13.9%). The weighted prevalence of audiometric notches in obese adolescents was higher compared to normal weight adolescents (24.8% vs 14.7%).

The prevalence of high frequency hearing loss (HFHL) was 14.3% among males and 8.1% among female adolescents and the difference was statistically significant. The weighted prevalence of high-frequency hearing loss in obese adolescents was significantly higher statistically compared to normal weight adolescents (17.9% vs 5.4%).

The prevalence of speech frequency hearing loss (SFHL) was 7.3% in males and 5.4% in females. The weighted prevalence of speech frequency hearing loss in obese adolescents was higher compared to normal weight adolescents (8.5% vs 5.4%), but the difference was not statistically significant.

Furthermore, the study found that the odds of having high-frequency hearing loss were higher in smokers compared to non-smokers.

Definitions in the study

In the study, the definition of a high-frequency audiometric notch was when:

• one or more of the thresholds (the softest sound a person can hear) at 3, 4 or 6 kHz exceeds the pure-tone average of the 0.5 and 1 kHz thresholds by 15 dB or more and
• the 8 kHz threshold is at least 5 dB lower (better) than the maximum threshold in the 3, 4 or 6 kHz range.

As with other studies using NHANES-data, the study used the average of four audiometric frequencies at 0.5, 1, 2 and 4 kHz to define the speech frequency pure-tone average and the average of the three audiometric frequencies at 3, 4 and 6 kHz to define the high frequency pure-tone average.

The study used a pure-tone average of 15 dB HL or greater in either ear as a cut-off threshold to define both speech frequency hearing loss and high frequency hearing loss.

About the study

The study used data from the American NHANES 2007–2010 surveys. NHANES is a cross-sectional, nationally representative survey of the non-institutionalised civilian population of the United States conducted by the National Center for Health Statistics at the Centers for Disease Control and Prevention (CDC).  1,469 adolescents participated in the study.

The study “Association of Obesity with Hearing Impairment in Adolescents” was published in the journal “Scientific Reports”.

Sources: www.ncbi.nim.nih.gov and Scientific Reports