Obese adolescents at higher risk of hearing loss

A new study has revealed that obese adolescents are more likely than their normal-weight counterparts to have hearing loss.

Findings showed that obese adolescents had increased hearing loss across all frequencies and were almost twice as likely to have unilateral (one-sided) low-frequency hearing loss.

"This is the first paper to show that obesity is associated with hearing loss in adolescents," said study first author Anil K. Lalwani, MD, professor and vice chair for research, Department of Otolaryngology/Head and Neck Surgery, Columbia University Medical Center.

The study found that obesity in adolescents is associated with sensorineural hearing loss across all frequencies (the frequency range that can be heard by humans); sensorineural hearing loss is caused by damage to the inner-ear hair cells.

The highest rates were for low-frequency hearing loss-15.16 percent of obese adolescents compared with 7.89 percent of non-obese adolescents. People with low-frequency hearing loss cannot hear sounds in frequencies 2,000 Hz and below; they may still hear sounds in the higher frequencies (normal hearing range is from 20 Hz to 20,000 Hz). Often they can still understand human speech well, but may have difficulty hearing in groups or in noisy places.

"These results have several important public health implications," said Dr. Lalwani, who is also an otolaryngologist at NewYork-Presbyterian Hospital/Columbia University Medical Center.

"Because previous research found that 80 percent of adolescents with hearing loss were unaware of having hearing difficulty, adolescents with obesity should receive regular hearing screening so they can be treated appropriately to avoid cognitive and behavioral issues," he added.

Dr. Lalwani and his colleagues speculate that obesity may directly or indirectly lead to hearing loss. Although additional research is needed to determine the mechanisms involved, they theorize that obesity-induced inflammation may contribute to hearing loss.

The study was recently e-published by The Laryngoscope, a journal published by the American Laryngological, Rhinological and Otological Society.