The Benefits of Exercise (and a caution)

Around the time our daughter was born, we had blood pressure screening one day at church and mine was surprisingly high. I had been very fit as a youngster and played a lot of sports. But in my mid 30s, I had gained weight and was not exercising. I was working too much, sleeping too little, and generally not being very healthy. The juxtaposition of the birth of our second child and the high blood pressure reading made me consider my responsibilities and resolve to do something about it. So I took up running.

It has been said that if exercise were a medication, it would be the most-prescribed drug of all because it is good for almost everything. Regular exercise decreases the risk of heart disease, high blood pressure, diabetes, some types of cancer, strokes, and arthritis. It increases bone strength, elevates mood, and improves energy levels and sleep.

So I started running, a little at first, then more. I eventually ran some 5Ks, then 10Ks, and then 10 milers. I lost weight, my blood pressure returned to normal, and I felt great. This progressed to a few half marathons and then some marathons (PR 3:16:04 for the runners out there). My training often required getting up in the wee hours of the morning to run or running with a head lamp at night. When I was on call, I would sometimes run laps around the hospital at night because I had to be able to get there within minutes if there was an emergency. In the process, I started getting more tired again, and then my leg started hurting. An MRI revealed a stress reaction in my tibia, the main bone in the lower leg.

What had started as an attempt to get healthy by exercising resulted in me exercising so much I harmed myself. My leg healed with rest and I started running again, now in smaller amounts. There is nothing wrong with running marathons, but in my particular situation, running had led to a different kind of unhealthy. I haven’t raced since that injury but try to run a few times a week. My blood pressure remains fine (110/74 earlier this week) and I think I am in pretty good shape for a guy my age (though I certainly can't keep up with my teenage children). Sometimes my exercise for the day is simply walking the mile to and from our mailbox to get the mail. Even that little bit makes me feel better. Or if I have had a stressful day, a quick five mile run is the best way to burn that stress away.

You don’t have to be an athlete or compete in things to benefit from exercise. Find something you enjoy – walking, hiking, riding bike, working in the garden, playing basketball or soccer, kayaking, chopping wood, etc. and do it regularly. Or better yet, do some combination of several different activities. You will feel better and decrease your risk of a variety of health problems.

Whatever Happened to Rotavirus?

We are in the midst of what used to be Rotavirus season. Rotavirus is a viral intestinal infection which causes fever, vomiting, and diarrhea and generally lasts 3-8 days. In some cases, it can lead to dehydration and hospitalization, particularly in infants.

In the “old days,” meaning before 2006, it was not unusual for us to have several infants with Rotavirus admitted to the hospital at the same time at this time of year. Rotavirus was part of the reason that our pediatric ward was often full in the winter, sometimes causing our patients to overflow onto the adjacent adult ward. We dealt with Rotavirus so often that the nurses on the pediatric ward could usually predict a positive test for it before we had the results based on the smell of the stool. In contrast, that same pediatric ward now rarely houses more than a couple of patients at a time, though the decrease is certainly not due only to fewer cases of Rotavirus.

The difference is that we now have an oral vaccine for Rotavirus that is given at two, four, and six months of age. Just two years after introduction of this vaccine, there was an 85% reduction in ER visits and hospitalizations due to Rotavirus nationwide.

Prior to the currently available vaccines, there was another Rotavirus vaccine on the market. It was quickly discovered that there was a small increase in cases of intussusception, a type of intestinal obstruction, in children who had received the vaccine and it was quickly withdrawn from the market.

The currently available vaccines have been watched closely for this same association and no increased risk of intussusception has been found. The successful reduction of Rotavirus infections is evidence for the efficacy of the vaccine as well as the mechanisms in place for detecting adverse reactions to immunizations.

Effects of Too Much Screen Time

Sometimes when there is a big weekend of sports on TV, I find myself watching for far too long. Not infrequently, this leads to a headache and general grumpiness. The same thing happens when I spend too much time on-line, whether I am just reading the news or watching something mindless. I do not think I am alone in this and there is plenty of evidence that TV and other screen time has deleterious effects on other people as well, including children.

Television watching in young children has been linked to an increased risk of ADHD and watching TV is associated with obesity and sleep problems in children as well. Think about what children are not doing while watching TV. Children need to be interacting with others, playing outside, solving problems while building forts with things they find, playing games, etc. Play is how children learn about the world and learn to interact with others. Some of my best childhood memories are of building dams in a pasture stream, exploring the woods, and baseball games in the back yard that lasted for hours. Debating a close call at first base and coming to a conclusion together is practicing for real life.

TV also exposes children to scenes of violence, advertisements for unhealthy foods, lots of advertisements for alcohol (especially if you like to watch sports), and sex without consequences. The amount of sex that is implied on TV comes with remarkably low incidences of sexually transmitted diseases and unwanted pregnancies. In real life, people actually do get pregnant and pick up diseases. I remember once while watching TV with one of my children I was asked during a beer commercial “Why is she out in the snow in her bathing suit?” A reasonable question for which I had no reasonable answer.

The American Academy of Pediatrics recommends no screen time for children younger than two and a maximum of 1-2 hours per day for children older than that. With the ubiquity of TVs, computers, tablets, smart phones, etc., it is easy to exceed that without even noticing.

So turn off the electronics and get kids outside playing or building a house in the living room with chairs and a blanket or just exploring the world around them. I know for myself, getting away from the TV or computer and going for a run, walking the ½ mile to get the mail from our mailbox, shooting baskets in the driveway, or even just sitting on the porch and watching and listening to birds and lizards can really improve the way I feel both mentally and physically. And it probably makes me more pleasant to be around as well.

Just Because Something Sounds True Doesn't Mean It Is

I have been thinking a lot about how easily medical misunderstandings happen and how easily misinformation can be propagated. Specifically, I have heard concerns from some patients that the commonly-used laxative, Miralax, contains antifreeze. Fortunately this is not the case. I helped take care of a child who had ingested antifreeze during my time in the Pediatric Intensive Care Unit as a resident at UVa. That is not something we would want any child to go through.

The confusion comes from the similar-sounding ingredients. The main ingredient in Miralax is polyethylene glycol and many brands of antifreeze contain ethylene glycol. It sure sounds like they are almost the same thing and would probably have the same effects, right? But they aren’t and they don’t.

Consider this. Regular table salt is sodium chloride. It tastes good and we need a certain amount of it to maintain proper electrolyte levels in our bodies. Using too much can increase blood pressure but we all use it and it is not acutely dangerous. One may then think that plain old sodium would react similarly, but it doesn’t. When placed in water, pure sodium reacts violently, bursting into flames. Obviously that would cause a very concerning reaction if it was on your French fries.

So even though the names are similar and both contain sodium, sodium chloride and sodium metal are completely different chemicals with completely different properties and effects. The same is true of polyethylene glycol and ethylene glycol.

So just because two things sound similar and it sounds true that they are the same, that is often not the case. Come to think of it, that applies to a lot more in life than just medicine and chemistry.

The Importance of Strep Tests

One of the most common reasons for patients to come see us is for a sore throat. Except in extremely unusual circumstances, the only bacterial cause of throat infections in children is strep throat. That means that strep throat is the only cause of a sore throat which will be helped by treatment with antibiotics. Furthermore, strep is less common than viruses as a cause of sore throats.

There is a quick, easy test to check for strep throat that involves swabbing the throat and testing for streptococcal antigens (essentially tiny pieces of the strep bacteria). These tests catch a very high percentage of cases of strep throat. If the strep test is negative, generally a back-up throat culture is performed to pick up the ones that sneak through unidentified.

Why is this important? Because doctors are not very good at diagnosing strep throat without the test. When I was in the first year of my pediatric residency at UVa, we had a contest to see who could best predict the results of strep tests on their patients. We wrote down our predictions prior to having the tests run and then calculated who had the highest percentage correct for the year. I was the “Golden Loop” winner for my year (named for the loop used to streak a sample on a blood agar plate for growing bacteria). Even so, I think my percentage of correct predictions was only around 70%. And after 18 years of practicing pediatrics and thousands of visits in which I have done strep tests, it is still not unusual for me to be surprised by the result of a strep test.

Some providers diagnose strep throat using the Centor criteria. These criteria were developed for adults. If a patient meets all of the criteria, their chance of having strep throat is around 50%. So if adults are treated based on these criteria alone, about half of them will receive antibiotics for a condition which they do not have. When applied to children, the predictive value of these criteria is even lower.

It is not unusual for us to see patients who were seen elsewhere for a sore throat, placed on antibiotics without a strep test, and are no better a couple days later. It is understandably frustrating for them to have a second visit for the same problem only to learn they have an illness for which the treatment they were prescribed would not be expected to be helpful.

Strep tests are quick, easy, and reliable. So the next time someone wants to treat your child’s sore throat with antibiotics without first testing for strep, request a strep test. There is a good chance it could save him from taking 10 days of antibiotics which will not help and could cause side effects. In addition, you will be doing society a favor. Overuse of antibiotics leads to antibiotic resistance and, according to one recent estimate, infections with antibiotic-resistant bacteria cost the United States $20 billion annually. The first, obvious step to combating antibiotic resistance and doing what’s best for patients, is to not use antibiotics for conditions they will not help.

How We Know What Works

One of the pillars upon which modern medicine is based is objectively determining if a certain procedure, treatment, etc. is the cause of a certain outcome.

For example, when the meningococcal conjugate vaccine was first introduced, there were reports of Guillain-Barre syndrome (a rare, temporary paralysis) in a few persons who had received the vaccine and some concern that the vaccine may have caused it. It turned out that when the data was analyzed, it was found that people who had received the vaccine were no more likely to get GBS than those who had not received the vaccine. So the few cases of GBS after vaccination were a coincidence. This concept is often summed up with the saying “Correlation is not causation,” meaning that just because two things have a temporal relationship doesn’t mean one caused the other. Now years later, we know that the vaccine does not cause GBS and we have been able to protect a multitude of young people against deadly meningococcal disease with the vaccine.

Similarly, it is important to have control groups to see if treatments work. If 80% of people taking Treatment A get better, it must work, right? What if 80% of people with the same disease who did not get Treatment A (the control group) also get better? Suddenly Treatment A doesn’t look so great.

In medical trials, treatments are usually compared to a placebo. A placebo is something that is made to look, taste, etc. like the treatment in question but has no medication in it (ie. a “sugar pill”). In an ideal trial, the patients and doctors do not know who is receiving a placebo and who is receiving the treatment being investigated. Then the results are compared to see if the treatment in question worked any better than the placebo.

This approach is what allows us to provide treatments that provide benefits to patients and avoid treatments that don’t work or may even be harmful. Stories of individuals’ experiences can guide further investigation, but it is often only when the experiences of many individuals are compiled in a systematic way which minimizes bias as much as possible that one can separate the wheat from the chaff.

 

Children and Second-Hand Tobacco Smoke

There are many reasons to avoid exposing children to second-hand tobacco smoke. We know that second-hand smoke exposure increases the risk of Sudden Infant Death Syndrome, respiratory problems, and learning and behavior problems.

A new study in the August issue of The Journal of Pediatrics suggests that exposure to tobacco smoke may also impair motor development in children. Children aged 7-9 had urine cotinine levels measured as a marker for exposure to second-hand smoke. Findings were adjusted to account for other factors known to affect motor development. The children with cotinine in their urine were more likely to have impairment in a variety of motor abilities including coordination, balance, and strength when compared to children who did not have cotinine in their urine.

A second study in the same issue of J Peds found similar impairments in motor development if children were exposed to tobacco prenatally through maternal smoking during pregnancy. When we think of tobacco smoke, we usually think about its effects on the respiratory system but it is clear that it also has effects on a child’s developing nervous system.

We would hope that no children would be exposed to second-hand smoke but we also recognize that it is very difficult for parents and family members to stop smoking. Keeping smoke as far away from children as possible is good but we also know that children whose family members smoke outside, away from them, will also get some exposure. Ultimately, stopping smoking is best for the smoker and everyone around him. It is possible to stop and I have had the opportunity to celebrate along with the parents of some of my patients when they have been able to quit.

For those who are interested in stopping, I would encourage you to talk with your own physician about options which may make it easier, for your own health and the health of those around you.