Hearing loss occurs early during the course of uncontrolled type 1 diabetes in children, researchers report. They say diabetic damage to nerves or blood vessels might be the cause.

Dr. Abdelaziz Elamin, of Sultan Qaboos University in Muscat, Oman, and colleagues followed 63 children younger than 18 years old with a confirmed diagnosis of type 1 diabetes, who were seen at the Khartoum Teaching Hospital, Sudan.

The children had had the disease for an average of five years at the time of study, and the condition was poorly controlled, the team notes.

Hearing assessments showed that all the children had some degree of hearing loss, but one-third of them had a loss of over 25 decibels that indicates functional impairment, the researchers report in the medical journal Indian Pediatrics.

Hearing loss was predominantly in the middle and high frequencies, which can affect speech discrimination, they add.

Overall, the hearing deficit correlated with the duration of diabetes, degree of control and insulin requirement. High-frequency hearing loss was associated with other complications involving the kidneys and retina, indicating that damage to blood vessels might be involved.

Blockage of the capillaries supplying blood to the inner ear, or damage to nerves involved in hearing, or a combination of the two could be responsible for the hearing impairment in type 1 diabetes, Elamin and colleagues suggest.

They think that tighter diabetes control “might prevent or delay this complication.”

SOURCE: Indian Pediatrics, January 2005.