Junkfood Science: Can being a chubby child really increase ear infections?

April 18, 2007

Can being a chubby child really increase ear infections?

If we believed the news earlier this week: “Overweight children are more likely to need ear tubes.” Even Forbes uncritically reported that a new study found “children who were treated for ear infections were fatter than the other children.” WebMD took an especially interesting angle, noting that “childhood obesity and otitis media with effusion are rising, but before now, no one had investigated whether the two conditions might be connected.” And by this morning, the headlines had grown to: “Childhood Obesity Causes Ear Infections.”

Parents have been unduly alarmed, because none of these claims were shown in the study being reported. The most surprising thing about the study, and I don’t say this lightly, was that it was published at all.

The study was led by Jong Bin Kim, M.D. with the College of Medicine at Kyung Hee University in Seoul, Korea, which some may recognize as also having one of most famous institutes of traditional Oriental medicine in the world.

They selected an experimental group of 155 children, 2-7 years old, who had been seen in their Department of Otorhinolaryngology (“ear, nose and throat”) for ventilating ear tube placements because of otitis media with effusion. As a control group, they selected, not healthy children in the community but, 118 sick children who were in the hospital having surgery for diseases unrelated to the head and neck. No other information about these children were ascertained or reported, such as their socioeconomic status, home or day care setting, parental situations, diet or health. What they stated was that the children coming into the clinic for ear tubes were fat, with an average BMI (body mass index) of 22, compared to the thinner sick children in the hospital, with an average BMI of 16.

The fat children had total cholesterol levels about 36 points higher than the children hospitalized and undergoing surgery — a meaningless finding. As any healthcare professional knows, that would be expected as it’s been known for decades that serum cholesterols drop with the stress of surgery (before, during and after). Larger children can also have higher cholesterol levels, another abstruse finding.

That’s it.

It’s obvious to anyone that the researchers examined two very different groups of children, making any comparisons illusory. Yet, this was the source of the Forbes report of fatter children being treated for ear infections. Probably not what you thought!

It is unclear why the researchers even bothered with a control group, though, because they didn’t even include those children in the rest of their paper. They went on to divide the group of children getting ear tubes into fat (41.9% of the kids) and nonfat (the remaining 58.1%) based on their BMIs. So, they actually reported there were fewer “obese” children than “nonobese” among those needing ear tubes. In fact, there were 27% more nonobese children getting ear tubes.

Their final conclusion stated that “the frequency of ventilating tube insertion in the experimental group was not related to obesity.” This contrasts with the media headlines, of course.

There was an especially peculiar finding, though: Oddly, they again stated that among the children getting ear tubes, the mean BMI of the “obese” children was around 22 and the remaining children had BMIs averaging around 15.7.

But the most glaring and implausible problem in the data was missed by every media and medical journalist review: A BMI of 22 in children this young is off the growth charts (whether using the CDC’s (pictured) or even moreso the International Obesity Task Force’s newly proposed cutoffs for Asian children ) and it is questionable that the average BMI of the fat group would be this extreme, while the average for all the rest of the children would fall so much lower. Even studies of Korean children 6 to 10 years older than the kids in this study don’t show such high BMIs or high prevalence among the “obese” category. Yet even peer reviewers didn’t throw it back for clarification or validation.

We could stop right there and toss this study, and I wouldn’t blame nonparents for clicking their mouses to more exciting research. But some additional information on ear infections may help concerned parents put into perspective the far-fetched speculations of a biological explanation for a connection between obesity and ear infections.

Ear infections are the most common infections, next to colds, seen in babies and young children. At least 80% of all little ones get them, with most being under the age of two. Young kid’s ear tubes (“eustachian tubes,” which connect the inside of the ear to the back of the throat) are smaller and more horizontal and don’t drain as well as in adults. When the middle ear gets swollen and fluid and mucus builds up, that’s otitis media. That gunk, which includes bacteria, can get infected, too. When fluid and mucus stay trapped inside the eustachian tubes, usually after an infection has cleared up, then it’s called otitis media with effusion (fluid). Surprisingly, most otitis media with effusion isn’t diagnosed because of any symptoms, but when a doctor looks in a child’s ear during a well-child exam. For most kids, it goes away by itself and doesn’t need antibiotics or treatment. [Antihistamines and decongestants haven’t been shown in randomized clinical trials to make a difference with effusion — in fact, antihistamines make secretions thicker and may worsen things.] But if the fluid stays clogged in there for months, it can damage their hearing.

As you can imagine, like any upper respiratory infection, ear infections are more common during the colder months of the year when kids are cooped up inside together, and in day care settings or when kids live and play in close proximity. It’s theorized that a polluted, dirty environment and allergies can inflame the lining of the ear tubes and increase secretions, too. Anyway, cases of otitis media with effusion may appear to be increasing in modern days, as more kids are in day care and attending preschools. Not because they’re getting bigger.

It used to be feared that otitis media with effusion might harm a child’s development, but that hasn’t been shown to be the case in recent randomized clinical trials. Socioedemographic factors are still what most affects development.

In this study, they were looking at kids who were getting ear tubes inserted. In some children, such as those with persistent hearing loss or speech delays from recurrent ear infections or those whose otitis media with effusion hasn’t cleared up after many months; an ear, nose, and throat doctor may suggest inserting tubes (called tympanostomy or pressure equalization (PE) tubes) to help fluid drain from the middle ear and equalize the pressure in the ear. The tubes usually stay in for 6 to 12 months and fall out on their own as the ear heals. But over the past couple of years, “watchful waiting” is increasingly what pediatricians are doing for most otherwise healthy kids. PE tubes were once believed to help prevent developmental problems in young children, but several recent clinical trials following children to 9 to 11 years of age haven’t found that to be the case for otherwise healthy kids. Most will turn out just fine either way.

So, once again, we have another contrived malady being blamed on “childhood obesity” based on no credible evidence. And no one interested in questioning it.

© 2007 Sandy Szwarc

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