Sunday, May 27, 2012

Screening for Prostate Cancer Not Recommended

In a draft statement issued last fall, the Unites States Preventive Services Task Force recommended that men over the age of 75 not be screened for prostate cancer with the PSA blood test. Their argument was that prostate cancer is so slow-growing that the test was likely to do more harm than good in older men. But for men under 75 (and that’s most of us), the evidence regarding the usefulness of the PSA test was considered inconclusive.

This month, however, the task force took a much firmer stance against routine screening for prostate cancer. Its recommendation is now unequivocal; healthy men need not be screened for prostate cancer with the PSA test, regardless of age. According to the task force there is “a moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits”. The task force also suggests that physicians should “discourage the use of this practice” (routine screening with the PSA test.)

The task force makes no recommendation regarding the use of the PSA test for surveillance of prostate cancer once it has been diagnosed. But healthy men, at least, can now skip the test and not feel guilty.

Wednesday, May 23, 2012

Another Way to Increase Organ Donations

As I’ve pointed out numerous times, there’s a critical shortage of cadaveric organs for transplantation into patients whose own organs have failed them. That’s why the news this month that Facebook would allow its members to list their organ donation status on their Facebook page was such welcome news. The hope is that social pressure, or at least the knowledge that their friends were doing it, would convince more people to become potential organ donors.

Researchers interested in organ donations are looking into other ways to increase organ donations as well. In one recent experiment, about half of all drivers arriving at a driver’s license renewal office to renew their license were shown a five-minute iPod video addressing common concerns about organ donation. The other half of the drivers did not see the video. Then in an exit poll, all drivers were asked to show the organ donor status written on their new licenses. 84% of the drivers who saw the video consented to be organ donors, compared to 72% of the group that did not see the video.

Apparently just a little effort to address people’s concerns about organ donation goes a long way toward convincing people to donate. Although the increase in willingness to donate after seeing the video was just 12 percentage points overall, that 12% is the equivalent of more than 40% of the 28% of drivers in the control group who chose not to donate after not seeing the video.

Monday, May 21, 2012

Is "Good" Cholesterol All That Good?

When it comes to cholesterol in your blood, all cholesterol is not the same. Statistically, people whose blood level of HDL cholesterol - the “good” cholesterol - is in the upper-normal range have reduced risks of developing heart disease. (And conversely, people whose LDL “bad”cholesterol is high have an increased risk of heart disease.) So it only makes sense that you should try to raise your HDL (and lower your LDL), right? This logic is so ingrained in us and in the medical profession that doctors routinely encourage patients with low HDL to change their diet, get more exercise, and take niacin (which is supposed to help raise HDL.) Drug companies have been trying to develop HDL-raising drugs for years - without success, I might add.

But now a new study casts serious doubt on the “good” cholesterol hypothesis. In the study, researchers reviewed the medical records of subjects with gene variations that cause the subjects to have high HDL levels. They hypothesized that subjects with high HDL because of genetic variations would have a reduced risk of heart disease. To their surprise, a high HDL due to an especially “good” genetic makeup had no effect on risk of heart disease.

So what’s going on? No one is arguing against the evidence that a high HDL is associated with a reduced risk of heart disease in normal persons, because it clearly is. But maybe the high HDL is not directly causing the reduced risk. (Remember, an association does not prove cause/effect.) And if a high HDL isn’t directly protective, then raising LDL through drugs or other means would be unlikely to be beneficial.

Incidentally, the same may not be true for the risk associated with high LDL, the “bad” cholesterol. Gene variations that caused high LDL levels were associated with increased risk of heart disease, as expected.

I’m guessing that this latest paper will lead to more research and a better understanding of the role lipoproteins play in the risk of heart disease. We need to find out, now, what’s actually lowering the risk of heart disease when we observe a high HDL, if in fact it’s not HDL itself.

Thursday, May 17, 2012

Does Repetitive Head Trauma Cause Brain Injury?

On May 2, 2012, NFL linebacker and 12-time Pro-Bowl selection Junior Seau committed suicide. He had retired in 2010 after 20 years in the NFL. His death brings up once again the very real possibility that repetitive head trauma in high-impact sports such as football may lead to a permanent degenerative brain condition called chronic traumatic encephalopathy (CTE.)

CTE can lead to depression, loss of memory, dementia, a loss of impulse control, and in the case of at least three ex-football players, perhaps even suicide. Former players are aware that there may be a looming problem with their future health, but no one knows how big the problem could be. One former player, Dave Duerson, allegedly committed suicide specifically so that his brain could be left to science for the study of CTE.

A possible association between repetitive head trauma and CTE was first proposed in 2002, when the neurofibrillary tangles that are indicative of CTE were found in the brain of deceased Pittsburgh Steeler center Mike Webster. The National Football League initially downplayed concerns, but when CTE was found in the brains of more than 50 deceased athletes who had participated in high-impact sports, the league changed its tune and has launched a comprehensive study to determine the extent of the problem.

Clearly, the NFL is between a rock and a hard place. A good, comprehensive study is sorely needed, but what if it shows that repetitive head trauma does lead to CTE? Many former players are already claiming that the dangers of repetitive head injury were ignored for too long. Over a thousand lawsuits are already pending against the NFL.

I’ll keep you posted as evidence for (or against) a causal relationship between head trauma and CTE becomes available. For now, we’re stuck with anecdotal reports, speculation, and of course, lawsuits.

Sunday, May 13, 2012

How Long Should You Breast-feed?

There’s been a lot of talk lately about a philosophy of parenting called attachment parenting. Promulgated largely by a popular child-rearing book called The Baby Book by Dr. William Sears, it’s three main tenets are: 1) breast-feeding, even for several years if mother and child wish 2) co-sleeping (baby sleeps with the parents) and 3) baby-wearing (babies are carried around in slings). The idea is that attachment parenting creates a strong bond between mother and child, so that ultimately the child grows up happier and better-adjusted.

Breast-feeding makes sense from a strictly biological perspective, whereas co-sleeping and baby-wearing confer largely psychological benefits. Breast-feeding provides partial immunity to the child against infectious diseases at a time when its immune system is not yet mature, and of course the nutritional value of breast-milk is essentially ideal. The bulk of the benefit of breast-feeding is in the first year, however. The American Academy of Pediatrics recommends that mothers breast-feed exclusively for six months, and then begin to supplement breast-feeding with solid foods until the end of the first year. Breast-feeding beyond the first year is thought to have more social and psychological benefit than biological benefit.

How do most mothers measure up? It’s complicated, because not all mothers have either the time or the inclination for attachment parenting or even for breast-feeding, especially if they work. According to the Centers for Disease Control, only 14% of babies are breast-fed exclusively until they are six months old, and only 33% are breast-fed exclusively for even the first three months. But before we get too worked up about these statistics, it’s worth remembering that although most children apparently are not breast-fed according to current recommendations, and there’s no convincing evidence that they are somehow disadvantaged as a result. So my suggestion would be that you follow the American Academy of Pediatrics guidelines if you can, but don’t feel too guilty if you can’t.

Monday, May 7, 2012

Facebook Encourages Organ Donations

Every year, nearly seven thousand of the people who are waiting for an organ transplant in the U.S. die before they ever receive an organ. The sad truth is that the number of organs available for transplant is falling farther and farther behind the growing demand for organs. Most states permit or even encourage persons to make their wishes regarding organ donation known on their driver’s licenses. And yet, fewer than half of all adults have indicated that they would be willing to be an organ donor in the event of their untimely death.

In what some people see as a move from social networking into social engineering, Facebook announced last week that it would encourage its members to list their donor status on their Facebook pages. Experts in the field of organ donation are pleased. It’s one thing to decide in private to be an organ donor – its quite another to make a public statement by announcing it to all of your friends. The hope is that peer pressure will cause some of the 160 million Facebook members in the United States (and 900 million worldwide) to join the organ donation bandwagon, adding millions of persons to the potential organ donor pool.

I’d like to see that happen. Though I’m not a Facebooker, I am proud to be a a potential organ donor. How about you?

Thursday, May 3, 2012

Testing Young Athletes for Heart Disease

Sudden death from heart disease is rare in young persons. However, the risk of sudden death is almost three times greater among athletes in high-risk sports such as basketball, football, and soccer, just because of the very physical nature of these sports. Approximately 90 young competitive athletes die suddenly each year from undiagnosed underlying heart disease. Is this enough deaths to warrant mandatory screening of all young athletes for underlying heart disease?

Sudden death from cardiac disease in young persons usually is due to either a problem with the electrical activity of the heart or to a condition called hypertrophic cardiomyopathy, a long way of saying that the heart muscle is abnormally thickened. Both conditions could be detected by an ECG (electrocardiogram). But an ECG is fairly expensive – more than $1,000 without insurance – which might prohibit some young athletes from participating in sports if it were required.

The American Heart Association does not yet recommend mandatory screening of all young athletes for heart disease, in part because of the high cost versus the small number of people who would benefit. However, a fairly recent paper in the Annals of Internal Medicine indicates that screening for heart disease might actually be cost-effective. The study’s authors estimate the long-term costs to society of treatment of cardiac disease in athletes found to test positive, as well as estimates of how many life years would be saved. The study finds that ECG screening would save an additional two life years for every 1,000 athletes tested, at a net cost of under $90 per athlete, compared to the current standard of just a history and physical.

Ultimately, someone will have to decide whether ECG testing of student athletes would be worth it. For now, it’s not required.