By Dr. Paul Ehrlich
Bed Sharing—Cause of Asthma, or Symptom?
First it was acetaminophen and asthma; then it was antibiotics and asthma. Is there anything we do to our children that doesn’t kinda, sorta, maybe correlate with asthma?
Now it’s kids who share their beds with their parents when they can’t sleep, as published in the European Respiratory Journal, and reported around the world.
“The study of 6,160 mothers and their children in Rotterdam, the Netherlands, showed no link between babies sleeping with parents and an increased risk of wheezing or asthma in the first six years of life. But bed-sharing at the age of two led to a 42% higher chance of wheezing symptoms at age three to six, and a 57% greater likelihood of being diagnosed with asthma at age six.
“Lead researcher Dr Maartje Luijk, from Erasmus University in Rotterdam, said: ‘The current study shows that there is an association between toddlers who share a bed with their parents at the age of two years and wheezing and asthma in later childhood. We postulated that the finding may be explained by parents taking the decision to share a bed with their toddler to monitor their asthma symptoms. However our results found no associations between pre-existing asthma symptoms in the first two years of life and bed-sharing at the age of two years.’”
As a parent, I am familiar with the phenomenon letting your kids get into bed with you. It’s not generally a life-style choice. It’s a compromise: Kids can’t sleep and they come and join mom and dad. Parents, anxious to get some rest themselves, acquiesce, and might or not carry the sleeping child back to bed. They don’t stay awake to monitor their child’s breathing.
Regarding the correlation with a later diagnosis of asthma, I have to point out that wakefulness in a child is itself often a symptom of asthma. There may be no outward signs of airway inflammation, coughing or wheezing, but trouble sleeping and other behavior may be an indication that something is going on. Years ago, I worked with the Asthma and Allergy Foundation of America (AAFA) to help establish a new diagnostic tool that centers on the quality of a child’s life.
We boiled it down to three simple questions: 1) Do you sleep tight? 2) Do you work right? 3) Do you play with might? If your child is missing out on these things, maybe she’s an undiagnosed or uncontrolled asthmatic.
Above all, don’t take this simple and utterly human response to a child’s wakefulness as yet another thing you did wrong that resulted in asthma.
Testing Revolution?
My second peeve for this season of peace on earth and goodwill towards humanity was an article in the New Yorker about a new medical testing company called Theranos, which is supposed to do for testing what Uber has done for the taxi industry (how’s that going by the way?). I have nothing against this tech-driven end run around the standard, highly concentrated industry, founded by Stanford drop-out Elizabeth Holmes, but I do quibble with one generalization she made in the article written by Ken Auletta. Fortunately, the heavy lifting on this was done by Johns Hopkins allergist, Corinne Keet, MD. She quoted from Ms. Holmes:
“The fact that in some states it’s illegal for someone to be able to get basic data about their body–for example, you’re pregnant or you’re not, you have an allergy or you don’t. Not a lot of sophistication has to go into the interpretation of that test.”
Dr. Keet comments, “As an epidemiologist who studies allergies and an allergist, I have to wholeheartedly disagree with this statement, and the problems with this statement have profound implications for the overall business model of Theranos.”
The menu of hundreds Theranos tests comes with price tags for each—a real boon for patients who would be able to give a small amount of blood and order tests at pharmacies at low cost, instead of the labyrinth of prescriptions, co-pays, and reimbursement they are subject to now. However, as you know from reading this website, allergy tests are not as black and white as pregnancy tests, although many doctors act as if they are.
The Theranos menu lists IgE (“quantitative IgE”) for $11.32, half the Medicare cost of $22.64. But what does this get us? Quantitative IgE, also known as total IgE, is a measure that only has meaning in the context of lots of other data and a medical practitioner experienced at interpreting the overall picture. It’s not an either-or thing like a pregnancy test.
As Dr. Keet writes:
“[I]f we took all children in the US, approximately 10% would test positive to peanut, while only about 1% have peanut allergy. That means that if you tested all kids in the U.S. for peanut allergy, 90% of positive tests would be false positives. Even if you used the higher cut-offs recommended in guidelines for interpretation of these tests, most positive tests would still be false positives, and with the higher cut-off you would miss a lot of real positives. False positives are not harmless, because they can cause fear, have social consequences and because unnecessary elimination diets can put people at nutritional risk. Of course, this doesn’t mean that food specific IgE is a useless test – just that we need to be judicious about who we test, and sophisticated about how we interpret the results in the context of other clinical data.”
Thanks, Dr. Keet.
As to the bed-sharing, my daughter slept in a crib for her first 3 years and those were the years that her asthma was the worst. As soon as she was transitioned to a big bed, I ended up bed-sharing, in large part due to wanting to monitor her and likely due to anxiety over all her past asthma exacerbations. I definitely don’t think, in our case, that her asthma was “caused” by the bed-sharing, since it wasn’t happening when her asthma was at its worst.
As for the Theranos issue, that worries me. The tests are not “black and white” and can be almost impossible to interpret in a vacuum. We eliminated many foods with low IgE values that later were found to be false-positives. It would be unfortunate for others to suffer the same fate when relying on a test that is not meant for use as a standalone diagnostic tool.