Monday, October 29, 2012

The Benefits of Quitting Smoking

Are you a smoker? Are you one of those who believe that smoking may not be as dangerous as “they” say it is?

Well, thirty years ago you’d have had a point.  It’s actually taken a long time to collect sufficient data to prove that smoking is as harmful as it is.  That’s because smoking-related diseases can take decades to develop.  Only after an entire generation of smokers reaches old age can we truly know the health-and-survival differences between smokers and non-smokers.  But the data are now becoming available, and its pretty convincing.  A 12-year-long British study of 1.2 million women born between 1938 and 1945 shows that women who smoked throughout their lives shortened their lives on average by more than ten years.  Ten years!  (The study was conducted in women born between 1938 and 1945 because smoking only became popular among women in the 1950s, when these women were entering their teens.)

Now for the good news.  Smokers who quit markedly reduced their risk of smoking-related diseases and a shortened lifespan.  How much their risk was reduced depended on the age at which they quit. For example, women who quit by age 40 lowered their smoking-related risk of death by 90%. Women who quit by age 30 lowered their risk by a whopping 97%.

What this means is that if you quit while you are still young, you can still live a long and normal life. Is that enough incentive for you to quit?

Saturday, October 27, 2012

Health Concerns Over Energy Drinks

The death of five teenagers since 2009 following the consumption of high-energy drinks has renewed calls for the FDA to do something about regulating these products. At the moment, the makers of energy drinks are not required to disclose how much caffeine their products contain, because they are marketed as beverages or dietary supplements, not drugs. But as the sales of such products have soared (doubling since 2006), so too have emergency room visits linked to energy drinks –over 13,000 in 2009 (the last year for which data are available), according to the federal Substance Abuse and Mental Health Services Administration.

Canada is ahead of the game when it comes to regulation of energy drinks, compared to the U.S. Under new Canadian rules, energy drinks will be limited to 180 mg of caffeine per can. That’s less than is in some of the most popular energy drinks, such as the 24-oz. can of Monster Energy and the 20-oz Red Bull. The American Beverage Association, which represents some of the energy drink companies in the U.S., has said it will resist the establishment of caffeine limits in the U.S.

How much caffeine can be packed into commercially-available caffeine products? A 3-tablespoon squeeze bottle of MiO liquid “water enhancer”, sold by Kraft Foods, contains over 1,000 mg of caffeine – roughly equivalent to 8-10 cups of coffee.

For more on this subject, go to a previous blog post titled "Alcohol and Caffeine - A Potent Mix."

Sunday, October 21, 2012

The HPV Vaccine and Sexual Activity

The vaccine against the HPV virus responsible for most cases of cervical cancer has been somewhat controversial ever since it first came out in 2006. The vaccine, called Gardasil, needs to be given before the onset of sexual activity to be completely effective because the HPV virus is sexually transmitted.  Generally the recommendation has been that it be given to girls at about age 11 or 12.

And that’s what has fueled the controversy; some parents have objected to the virus being given to girls that young because they believe it may encourage sexual activity at an age when it really isn’t appropriate.  As a result, many girls have not been vaccinated against the virus when they should be.  Are the parental concerns justified?

Shortly after the vaccine became available, several studies reported that administration of the vaccine did not seem to encourage sexual activity.  However, the early studies were based solely on sexual activity surveys, admittedly not the best way to collect accurate data.  Now a new study published in the journal Pediatrics confirms the earlier studies with data that are independent of self-reports.  The authors of the study examined the medical records of nearly 1,400 girls aged 11 through 12 for up to three years, looking for indirect evidence of sexual activity such as pregnancy, sexually transmitted infection, or contraceptive counseling.  The authors found no evidence of increases in any of these measures in girls given the vaccine at age 11 or 12, versus girls of the same age not given the vaccine.  So at least by these measures, there is no evidence that girls given Gardasil are more likely to engage in sexual activity at an early age.

Hopefully this will relieve some parents and encourage them to have their girls vaccinated.  Currently only about half of all 13- to 17-year-old girls have been vaccinated against HPV; far less than have been vaccinated against non-sexually transmitted diseases such as tetanus and diphtheria, and whooping cough.

Sunday, October 14, 2012

Journalistic Bias in Science Reporting

How good are newspapers at reporting on follow-up scientific studies on a particular subject, as opposed to focusing only on the initial high-profile hypothesis?

To find out, a team of scientists from France and the U.S. identified the top ten most cited scientific articles published in the 1990s on Attention Deficit Hyperactivity Disorder (ADHD). Then they examined the follow-up scientific articles related to each of the ten articles to try to ascertain whether the initial hypotheses in those ten articles had actually stood up to subsequent scientific evaluation. Lastly, they looked at newspaper coverage of both the top ten articles and the follow-up articles. According to the team of scientists, only two of the top ten most cited articles on ADHD were subsequently fully confirmed by other scientific articles. The other eight were either refuted, “strongly attenuated”, or considered unlikely by subsequent scientific articles. This is exactly how good science works; through a continuous process of tests, hypothesis modification, and retests, we come ever closer to the truth, and its not always what it seems at the beginning.

Newspaper coverage of ADHD, however, showed a distinct bias toward the sensational new hypothesis or initial findings, regardless of whether the hypothesis or the findings later proved to be true or not. There were 223 newspaper articles covering the hypotheses and initial findings of the top 10 scientific studies on ADHD in the 1990s. In contrast, there were only 57 newspaper articles covering all 67 scientific follow-up studies, and only one of those newspaper articles reported that a “top 10” paper was being “attenuated” by the newer scientific study’s findings.

No wonder the public is confused. They learn something from the public media one day, and never learn later that our knowledge about the subject has changed through good scientific investigation. Or as the study’s authors put it, “Because newspapers failed to inform the lay public that most initial scientific claims were later refuted or strongly attenuated, they did not reflect the evolution of scientific knowledge."

Saturday, October 13, 2012

Arctic Sea Ice Continues to Melt

2012 was another record year for the lowest amount of sea ice in the arctic during the summer, according to the National Snow and Ice Data Center (NSIDC). At its lowest point in September, sea ice covered only 3.61 million square kilometers of the Arctic Ocean. The arctic ice has been declining steadily for several decades now; coverage is currently less than half of what it was in the 1980s. If this keeps up, within several decades the arctic ice could come close to disappearing every summer. That can’t be good for polar bears…

Climatologists believe that the decline is a due global warming. Warmer air melts more ice, of course. But scientists postulate that the rapid melting is also due to warmer waters from the North Atlantic that are entering the region. In addition, warm air picks up more moisture, leading to clouds that trap even more warm air below them.

Interestingly, the ice cover over Antarctica (at the south pole) has actually increased slightly since the 1980s, according to the NSIDC. Climatologists explain this, too, as due to global warming. Specifically, as the Pacific Ocean warms up it delivers more moisture to the strong winds that blow in a circular pattern around the perennially cold Antarctic, and this leads to a greater snowfall over the Antarctic.

We’re just beginning to see the many and varied effects of global warming.

Tuesday, October 9, 2012

Drug Compounding Pharmacies

In the past few weeks, 119 people have come down with a rare condition called fungal meningitis (a fungal infection of the meninges of the central nervous system), according to the CDC. Eleven people have died. An investigation into the rapidly rising number of cases of the condition (which, by the way, is not contagious) quickly focused on a batch of steroid drugs that had been prepared at a Massachusetts-based drug compounding pharmacy.

Drug compounding pharmacies provide an important service to the health care industry. Drug compounding pharmacies don’t actually make drugs; they buy FDA-regulated drugs in bulk from the drug’s manufacturer and then repackage or reformulate them according to the needs of their customers. Perhaps the customer (such as a major hospital or a chain of medical clinics) requests a specific dose of a drug in a specific-sized vial, or wants several different drugs combined in a single vial or pill. Drug compounding pharmacies prepare the vials or pills accordingly.  In the current case, the compounding pharmacy was preparing vials of steroids in a liquid form for injection into patients’ spinal cords, for the control of pain.  Apparently some of the vials of steroid became infected with an unknown fungus.

Because drug compounding pharmacies don’t actually make the drugs, they are not subject to the same oversight by the FDA as are the drugs’ manufacturers. Instead, like all pharmacies, they are regulated by state laws. Perhaps this recent outbreak of meningitis will lead to a review of how the industry is regulated and inspected by the various states, because here’s a case where a mistake at a compounding pharmacy in one state has apparently lead to cases of fungal meningitis in 10 states at last count, and deaths in four. We need to have confidence that our drugs (and their various formulations) are safe when they cross state lines.

Tuesday, October 2, 2012

Knee and Hip Replacement Surgeries are on the Rise

The surgical techniques required for successful replacement of knee and hip joints (knee and hip arthroplasties) were first developed in the 1950s and ‘60s. The mechanical devices used to replace damaged knees and hips became commercially available in the 1970s. Today, over a million total hip and knee replacements are performed in the United States every year, according to the National Hospital Discharge Survey of the CDC. There’s even a specialist group of surgeons who focus primarily on these two surgeries (the American Association of Knee and Hip Surgeons).

Why are these two surgeries becoming so commonplace? For one, the surgeries are highly successful at eliminating the pain associated with hip and knee osteoarthritis. They’re also fairly low-risk. People are living longer and want to maintain their mobility as long as possible. And last but probably not least, the rate of obesity continues to rise in this country. Obesity places an extra burden on knee and hip joints, increasing the risk of the development of knee and hip osteoarthritis.

The number of knee and hip arthroplasties is expected to top 4 million per year by 2030. The American Association of Knee and Hip Surgeons is going to need a lot of new members by then….