Childhood obesity increases risk of hearing loss

Sharon Kirkey, CanWest News Service

Published: Tuesday, April 17, 2007

Fat children may be at increased risk of permanent hearing loss from chronic ear infections, new research suggests. A study involving 273 two- to seven-year-olds found those who had ear tubes inserted for middle-ear effusions — also known as "glue ear" — were significantly more likely to be overweight than children undergoing surgery for other conditions.

Ear infections cost Canada's health system $600 million annually and ear tube surgery is the second most frequently performed operation in children, according to the Canadian Task Force on Health Prevention. More than 20,000 children in Ontario alone have ear tube surgery each year.

The study from Korea may help partly explain why rates of otitis media with effusion (OME) are rising along with the growing number of too-heavy children.

Overweight and obesity rates among Canadian children have ballooned in recent years, with the proportion of obese kids nearly tripling in the past 25 years. Doctors are treating four- and six-year-olds with high cholesterol because of their weight. Overweight children are also at increased risk of diabetes, high blood pressure, sleep apnea, asthma, abnormal blood clotting and weak joints.

Over recent decades, rates of OMEhave been growing, a phenomenon that has been linked to more children in day care, pollution, bottle-feeding and other factors.

The condition results when the tube that connects the inside of the ear to the back of the throat becomes inflamed and blocked. Fluid accumulates in the middle ear cavity and bacteria in the ear multiply. The fluid can be thin and watery, or thick and gluey.

Usually, there aren't any of the normal symptoms of an ear infection, such as ear tugging, earache or fever. Untreated OME can cause hearing loss that can range from a few decibels to as many as 50. Rare, repeated infections can lead to permanent hearing damage, causing delays in speech, language and learning.

Obesity can cause inflammation throughout the body, and an earlier study found that the more a child weighs, the greater the risk of eardrum abnormalities.

In the new study, researchers compared 155 children (85 boys and 70 girls) who had ear tubes inserted for chronic OME to 118 children who had surgery for conditions other than ear disease and who had no history of OME. The children's body mass index, total cholesterol and triglyceride (a type of fat in blood) were measured.

The average body mass index was higher in the ear tube surgery group — 22 versus 16.3. Their total cholesterol levels were also higher. There were no significant differences in triglyceride levels.

Among the children who had ear tubes inserted, 42 per cent were obese.

The study is published in this month's issue of the journal Archives of Otolaryngology - Head and Neck Surgery.

skirkey@canwest.com