Surgery for Weight Loss May Save Lives

If stodgy medical journals ever hyped themselves, last week’s New England Journal of Medicine could have been hyped as the special weight-loss surgery issue.  It featured two studies that examined the effects of weight-loss surgery on mortality, and an editorial which discussed the findings of the two studies.  The studies received much press coverage, including this LA Times article.

Both studies compared obese patients who underwent surgery for weight loss to patients who had the same weight and age who did not have surgery.  The studies were not randomized.  Patients and their physicians decided if surgery was appropriate.  They weren’t randomly assigned to a surgical group or a non-surgical group.  Both studies followed the two groups of patients for a number of years and found fewer deaths in the patients who had surgery.  The death rate from heart disease and diabetes was lower in the surgery group, and surprisingly so was the death rate from cancer.  This is the first time that studies have suggested that surgery for weight loss may be life saving.

Last year, I wrote about a study which showed that gastric banding (the least invasive weight-loss surgery) led to more weight loss and a higher quality of life than diet and exercise.  As surgical techniques improve and the risk of surgery diminishes, this will be an increasingly realistic option to the very many people whose attempts at diet and exercise have been unsuccessful.

Tangential Miscellany:

Have a relaxing and happy Labor Day weekend!

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Vitamin D Deficiency is Common and Dangerous

Two weeks ago I warned you about excessive sun exposure.  Ironically, this week I’m warning you about a consequence of insufficient sun exposure.

A recent article in the New England Journal of Medicine exposes a very common and under-diagnosed problem, vitamin D deficiency.  This has become a bigger problem as our activities have moved increasingly indoors, and is even more common in Europe where food fortification with vitamins is rare.  The article cites studies that show that more half of post menopausal women taking medications for osteoporosis are deficient in vitamin D, and children and young adults are frequently deficient as well.

The effects of vitamin D deficiency on bone health are well understood.  Vitamin D deficiency leads to osteoporosis and in extreme cases to rickets.  Vitamin D is also essential to muscle function, and an intriguing study a couple of years ago also linked vitamin D deficiency to an increased frequency of falls in the elderly.  The article also cites many other studies that implicate vitamin D deficiency in a host of other diseases, from heart disease to colon cancer.  Most of these studies are observational, not experiments, so I’m not prepared to accept that vitamin D deficiency causes everything from bubonic plague to inflation, but the widely accepted effects on bone health and falls are reason enough to take it seriously.

There are two important points to take away from the article.  The first is that vitamin D deficiency is very common and easily diagnosed with a blood test called 25-hydroxyvitamin D.  The second is that the current dietary guidelines for vitamin D are likely insufficient and that everyone should be encouraged to get at least 800 IU of vitamin D daily.  For post-menopausal women who have been encouraged to take calcium and vitamin D supplementation, that will likely mean switching to a supplement with more vitamin D.  For example, Oscal + Extra D has 500 mg of calcium with 400 IU of vitamin D, so taking one tablet twice a day would give 1 gram of calcium with 800 IU of vitamin D.

(Thanks to my partner, Dr. Rubencio Quintana, for brining this article to my attention.)

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Antimicrobial Soap no Better than Plain

In our germ-phobic culture antimicrobial soap, once only used in hospitals, has become very popular in households.  This issue of the journal Clinical Infectious Diseases contains a study which reviews the literature comparing antimicrobial soaps versus plain soap.  The results of the study was reported in many media articles, including this Washington Times article.

The study reviewed both the soaps’ ability to kill germs on hands and their ability to prevent actual infectious diseases.  The surprising results were that antimicrobial soap was no better than plain soap from removing bacteria from hands and did not lead to lower incidence of infectious diseases.  Even worse, antimicrobial soap seems to select for resistant bacteria that are also resistant to conventional antibiotics.

It’s comforting to know that in the twenty first century there’s still nothing better to wash hands with than plain soap and water.

Tangential Miscellany:

Further proof that you’ll read it here first and it’ll still be true months later.

In January I wrote about the CDC warning about the dangers of cough and cold medications in children.  This week, the FDA released a strongly worded Public Health Advisory that every parent of small children should read.

In May I asked you not to panic about the concern that Avandia increases heart attack risk.  A study in an upcoming issue of the Annals of Internal Medicine finds that the effect of Avandia on heart attacks is still uncertain.

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Good Day, Sunshine!

With the long days of summer upon us, many of us are hitting the beaches and getting suntans.  Southern California is obsessed with both beauty and health, and tanning sits at the intersection of the two.  Suntans have become symbols of status, health and beauty.

But why?  There are certainly no health benefits to tanning, and many health risks.  Dermatologists have been warning us for over a generation that sun exposure increases our risk of melanoma, the most dangerous form of skin cancer.  It certainly increases the risks of less serious skin cancers too, not to mention wrinkling and other forms of skin damage.  The Darker Side of Tanning, a publication of the American Academy of Dermatology details the dangers of tanning.  They should hand it out at beaches and indoor tanning centers.

Sunshine certainly has a couple of health benefits.  Sunshine stimulates our skin to make vitamin D, but the amount of sunlight needed for adequate vitamin D is just a few minutes a day, much less than is needed for tanning.  (And you can get vitamin D in fortified foods or in supplement pills and skip the sun altogether.)  The other benefit to sunshine is its effect on our mood.  There is no question that sunshine (or bright fluorescent light which has the same color spectrum) elevates our mood.  Some people even get depressed when the daylight hours shrink in the winter, a condition called seasonal affective disorder.  But we don’t need to tan to get the mood-elevating benefits of longer days.  It’s enough to just see the sunlit outdoors though a window (which blocks harmful ultraviolet rays).

So why do we associate tans with health and beauty?  Like many other modern standards of beauty, the answer is purely passing fashion.  Before the beginning of the twentieth century tans were considered evidence of low status, since it implied having to do manual labor outdoors.  The wealthy worked very hard to avoid the sun and used makeup to lighten their skin.  Then, in the twentieth century, when most labor moved indoors, suntans became a symbol of affluence and leisure, suggesting a lifestyle that can afford a beach vacation.

So I encourage you to start a new trend.  Perhaps we can make it cool to have skin that’s as brown, black, yellow or pink as the day we were born.  That would be healthy, and in my opinion, beautiful.

Tangential Miscellany:

In case you were looking for more misleading meaningless studies that nevertheless get a lot of attention, here’s another study to ignore.

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Zinc Unproven in Treating Common Cold

I know I just wrote about the common cold two weeks ago, but I don’t make the news, I just report it.

This week the news is about zinc.  A study in the journal Clinical Infectious Diseases reviewed all the studies in the medical literature on the efficacy of zinc for the common cold.  The study attracted some coverage in the general press including this article in Fox News.  The review simply found that the majority of studies were too small or too poor in quality to draw a definitive conclusion.  So even though most of the lay press headlines are suggesting that zinc isn’t effective in colds, a more honest conclusion is that we don’t know yet.  In the authors’ own words:

This structured review suggests that the therapeutic effectiveness of zinc lozenges has yet to be established.

Tangential Miscellany:

Our receptionist, Jennifer, will be leaving us to enroll in nursing school and pursue her dream of a career in nursing.  We wish her much success.  We are excited that our new receptionist, Jaymes, comes wonderfully recommended by physicians we know and respect.  He has many years of experience listening to, advocating for, and helping patients.  Please help us welcome him, and go easy on him the first couple of weeks!

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More Studies to Ignore

I wrote back in January about the large numbers of studies that are publicized in the media that doctors and patients are better off ignoring.  I usually try not to give these studies any attention, but this week a study got so much media coverage that I felt I had to tell you all to ignore it.

This study in the journal Circulation looked at participants in the Framingham Heart Study (a large study of heart disease risk factors that started in the 1940s) and looked to see if a link existed between soft drink consumption and the metabolic syndrome.  The metabolic syndrome is a collection of factors (abdominal obesity, elevated blood glucose, elevated blood pressure, elevated triglycerides, and low HDL) that increase the risk of developing diabetes and heart disease.  The study found that those who drank soft drinks were at higher risk of developing the metabolic syndrome than those who didn’t, even if those drinks were diet (non-caloric artificially sweetened) drinks.  This apparently surprising finding generated much media coverage including this article in the Washington Post.

The problem with this study is the same as the problem with all the studies we should ignore.  It was an observational study, not an experiment.  (Check out my January 5 post if you need a refresher on the difference between observational studies and experiments.)  The study didn’t tell some people to drink soft drinks and some people to drink tap water.  It simply observed what they were already doing.  So the study can’t suggest that soda drinking causes the metabolic syndrome, just that the two things tend to happen in the same people.

There is no likely mechanism through which diet sodas can cause the metabolic syndrome.  What is much more likely is that people who tend to be heavier tend to like drinking sweet drinks, so they drink more soft drinks (both diet and regular) than skinny people.  So soda drinking almost certainly doesn’t cause metabolic syndrome.  A drive to consume sweets is likely behind both soda drinking and the metabolic syndrome.  So please, ignore this study.

I’m grateful to my patients Luetrell T. and David D. for sending me links to articles about this study.

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Vitamin C Can Prevent the Common Cold in Extreme Conditions

The Cochrane Reviews are systematic rigorous reviews of the medical literature on medical therapies.  Because of the objective and comprehensive methods they use for finding all relevant studies and categorizing them by quality, they are regarded as one of the gospels of evidence based medicine.

Recently the Cochrane Reviews published this review of the medical literature on vitamin C for the prevention and treatment of colds.  The study was publicized in this WebMD article.  The results are summarized below.

In studies on the general population, taking vitamin C daily year-round did not prevent getting colds but reduced the duration of colds slightly (8% duration reduction in adults, 14% in children).  The exception was in studies done under extreme low temperature or extreme physical stress, for example studies on marathon runners, skiers, and soldiers in sub-arctic conditions.  In these extreme conditions, daily vitamin C decreased the incidence of colds by about 50%.

In studies that looked at taking vitamin C only once a cold has started, there were no significant differences between vitamin C and placebo.

So, if you take vitamin C only once you’ve caught a cold, you might as well not.  To have any benefit, you have to take it preventively every single day, and for that effort you only get an 8% reduction in the duration of a cold.  This amounts to a 7 day cold being only 13 hours shorter.  For most people, that’s not really worth it.  On the other hand, the authors suggest that if you will be engaging in very strenuous physical activity or exposed to very cold temperatures, daily vitamin C is worth the trouble.

Tangential Miscellany:

Thanks to David W. for pointing out this letter in the New England Journal of Medicine which documents a rare danger of using earphones outside during a thunderstorm.  Ouch!  There’s no mention of what music he was listening to.  I hope it was something great.

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Sorrowful About Selenium

This week another dietary supplement moves from the “not proven to have any benefits” column to the “potentially harmful” column.  A study in the Annals of Internal Medicine which was reported in this CNN article is the largest study yet to look at the effects of selenium on the development of diabetes.

This story actually starts over a decade ago with a study designed to test if selenium prevents cancer.  The authors randomized 1,312 patients of a dermatology clinic with a history of skin cancer to receive either a selenium supplement or placebo.  The patients were then followed to see if selenium led to a lower risk of developing new skin cancers.  It didn’t.  (The results were published in this 1996 paper in the Journal of the AMA.)

In this week’s study the data from the first study was re-analyzed looking at the development of diabetes.  Patients who had a diagnosis of diabetes at the start of the study were excluded, and numbers of patients in each group who developed diabetes during the initial trial were counted.  Surprisingly, the patients in the selenium group developed diabetes more frequently than the placebo group at a rate that suggested that for every 25 people who take selenium rather than placebo for 10 years one additional case of diabetes would result.

So selenium doesn’t prevent skin cancer and may actually increase the risk of developing diabetes.  Of course we already have lots of ways to increase the risk of diabetes.  My favorite one is cheesecake.

Thanks to Linda T. for pointing me to this story.

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Discomfort of Air Passengers Relates to Cabin Pressure

This week’s New England Journal of Medicine published a study funded by Boeing which has received much media attention, including this Washington Post article.

The study sought to reveal the effects on passengers of different cabin pressures during prolonged flights.  The authors hoped to find whether different pressures made passengers uncomfortable or caused acute mountain sickness, an illness marked by headache, shortness of breath and nausea which is caused by rapid altitude gain.  Typically airplane cabins are pressurized to a pressure equivalent to an altitude of 8,000 feet, since maintaining normal atmospheric pressure during a flight would require much more fuel and would increase wear on the airframe.

The study placed volunteers in a hypobaric chamber to simulate a 20 hour flight.  Simulated flights were conducted with the chamber pressurized to different altitudes and the patients were monitored for adverse events.  They also completed a questionnaire about their symptoms.  For the sake of realism, I hope they underwent a prolonged and detailed security screening and had their deodorant summarily confiscated.

The good news is that no one developed acute mountain sickness.  Passenger discomfort, however, increased with decreasing pressure.  There was less discomfort when the cabin was pressurized at 6,000 feet than 8,000 feet.  Since Boeing sponsored this study, I assume they’re about to announce sales of an airframe that remains pressurized to 6,000 feet, heralding a new era of travel comfort.

At least now I know why I was uncomfortable during our family’s recent flight to Orlando.  Until this week I thought it was because the food was horrible and my three year-old wouldn’t stop hitting me.

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Book Review: The Cure

Dr. David Gratzer is a psychiatrist who has worked both in Canada and in the United States.  His first book, Code Blue: Reviving Canada’s Health Care System, was an award-winning prescription for the long waits and poor satisfaction currently plaguing Canadian patients.  In his current book, The Cure: How Capitalism Can Save American Health Care, Dr. Gratzer turns his attention to the troubles of the healthcare system on our side of the border.

Dr. Gratzer is certainly no apologist for American medicine.  He is quite frank about the problems we face, from skyrocketing costs, to the number of uninsured, to the increasing regulation of medical practice.  But Dr. Gratzer also trumpets the enormous achievements of American healthcare.  As he documents, nowhere in the world is one more likely to survive breast cancer, less likely to wait a long time for elective surgery, or more likely to spend more than 20 minutes with one’s doctor.

Ironically, faced with our current challenges American politicians increasingly look to Canada and to Europe for inspiration, even as Canadian and European governments are struggling with the consequences of their government-run healthcare systems.  Dr. Gratzer highlights the serious challenges in these countries, and how they are trying to inject competition and incentives into their healthcare models.

The Cure is a well researched and very readable analysis of what’s wrong with our healthcare system, and how to fix it.  Our nation tends to reject political extremes and is suspicious of revolutionary change.  The government-sponsored healthcare reform proposed by President Clinton’s administration met with widespread resistance.  On the other extreme, the Nobel Prize winning economist Milton Friedman in 2001 proposed a free-market reform of healthcare that would have eliminated government’s role in medicine.  Friedman’s plan would be politically impossible in the current climate.  Compared to these two extremes, Dr. Gratzer’s prescriptions are quite moderate, and therefore potentially achievable.  His proposals include adding competition to Medicare, reforming the FDA, and allowing patients to buy health insurance from other states.

For anyone interested in healthcare from a national point of view, The Cure is mandatory reading.

Tangential Miscellany:

I wish you a very happy Independence Day!

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