vaccines and autism

CBS interviewed Dr. Healy, and now seems to think this is an 'Open Question'. From the interview,
"why in the past decade hasn't the government compared the autism/ADD rate of unvaccinated children with that of vaccinated children?"

Because this has been done before, many times. No link between vaccination and autism has yet been found.
From an article in the Guardian:
"The Danish Epidemiology Science Centre compared 440,000 children who had MMR with 97,000 children who didn't. The children who had MMR were no more likely to develop autism than the children who didn't. A group in London looked at 498 children with autism, to see if they developed it after MMR. They looked at when they had the MMR jab, and when they developed the symptoms or the diagnosis, and found no sudden blip after immunisation. Another paper shows no increase in GP consultations in the six months after immunisation. Two hundred children in London and Stafford with autism were studied to see if there was a new type of autism related to MMR, featuring bowel problems and sudden regression, a bit like in the drama: half had the jab, half didn't, and there was no difference in type of autism between the groups. In California, looking at 1,000 children a year, over 14 years, the number of cases of autism increased by 373%, while the number of children getting MMR increased by only 14% (from 72% to 82%). "

If anyone has published studies showing evidence of a link, I'd surely like to see it.

From the interview again,
"If we can screen children to see which ones might be more susceptible to vaccine side effects.."
There is no known theory and no plausible biological mechanism for vaccinations to cause autism. So how could this screening be done ?
At one point thimerosal was postulated as a possible link. That's a separate discussion, but irrelevant now: child vaccines containing thimerosal are no longer used. Since then, there hasn't been any new causation mechanism proposed.

Also, a study in Japan, published in New Scientist print edition, 17 February 2001:
Journal reference: Journal of Child Psychology and Psychiatry (DOI: 10.1111.j.1469-7610.2005.01425.x)
"They found that the number of children with autism continued to rise after the MMR vaccine was replaced with single-shot vaccines. The medical records of 31,426 children in the city of Yokohama were checked. Before the vaccine was withdrawn, between 48 and 86 children per 10,000 were diagnosed as autistic. After the vaccine was withdrawn, 97 to 161 children per 10,000 were diagnosed with the condition."

There is considerable evidence that the "increase" in autism rates is an artifact of better diagnosis. See the Journal of Pediatrics, and the British Medical Journal.

If you want scary, contemplate thousands of children in iron lungs with polio, thousands of children blind or brain-damaged by measles, epidemics of whooping cough and thousands dying, malformed babies due to their mothers being exposed to rubella, etcetera. This is a certain result of large-scale refusal of vaccinations for populations at risk.

While Dr. Healy has undoubtedly done a lot of good work in the world, I suspect there may be a political aspect to this. Note that Dr. Healy is a Republican political appointee, and was "a member of the Advisory board of The Advancement of Sound Science Coalition, an organization later shown to have been founded by PR firm APCO and funded by the Phillip Morris corporation to criticise scientific research inimical to the interests of tobacco companies and other corporations" (Wikipedia). I don't see what advantage there is to starting this particular hare again, but I suspect it's there. It may just be part of the broader front in the Republican war on science.

The benefits of vaccination are proven. The hypothesis of a link between vaccination and autism is speculative and has no theoretical or evidentiary support. That doesn't mean it does not exist, only that it's unlikely in the extreme. From a public health perspective, investing in studies of a speculative unsubstantiated hypothesis is not easily justified.

Update September 2008: hm, now it appears Lance Armstrong is going anti-vaccine. Science saved his life and career, but now he's joining the druids, the forces of old night and chaos.
Further reading on the subject, rather better-informed than my brief jog through it, here and elsewhere on the scienceblogs.com site. Predictably, measles is first to make a comeback, but the other horsemen aren't far behind.
Some measurements of the number of lives saved by vaccines is at sciencebasedmedicine.org

More on the horrorshow that preceded immunizations at Making Light.

asthma and doping

Petacchi, the dominant sprinter of the last few years, has been suspended until August by the not-august Court of Arbitration for Sport: for a doping violation involving the asthma drug salbutamol (yclept albuterol in the USA).

In the article, it's claimed that 'Salbutamol can be used to increase an athlete's anaerobic power. '

I have adult-onset asthma, and take salbutamol when racing. The reason I noticed the asthma was that my 5k run times were 10-20% slower at maximal effort, than what training results predicted, with the addition of unusual distress. My training logs go back to 1975, so there's enough data there that I at least am satisfied that the predictions are reasonable. Tests confirmed the diagnosis, so I take it as prescribed now. With salbutamol, performances are back to normal: but I have never been able to measure any performance enhancement, even when running short maximal-effort intervals (400m repeats).

So I took a closer look at the data. The studies that show improvement in anaerobic power used a dosage of 12 mg/day for four weeks. See
http://bjsm.bmj.com/cgi/content/abstract/40/7/627

That's 12 milligrams a day. To put this in perspective, an inhaler delivers about 200 micrograms per dosage. The anaerobic power improvements require 12 000 micrograms per day. This is equivalent to 60 metered doses from an inhaler. That's a dose every 16 minutes (assuming 8 hours sleeping), for four weeks. It's impossible to hit this dosage except by taking it orally or intravenously. It's clear that Petacchi wasn't doing this.

There are also lots of studies showing that at dosages that can be delivered via inhaler, there are no measurable performance improvements, aerobic, anaerobic or anabolic.
See for example
- The effects of albuterol on power output in non-asthmatic athletes, LEMMER J. T et al,
International journal of sports medicine ISSN 0172-4622 1995, vol. 16, no4, pp. 243-249 (33 ref.)
- The effect of salbutamol on performance in endurance cyclists, Norris Petersen and Jones,
European Journal of Applied Physiology ISSN 1439-6319 (Print) 1439-6327 (Online), Volume 73, Numbers 3-4 / May, 1996

Then there is the question of how the salbutamol dosage is measured. WADA's measure is 1000 nanograms per milliliter (ng/ml) in the urine. This is not a very good measure. See for example this study, which notes:
"Urine cSAL increased with dose and was highly variable, with the peak value observed being 831 ng x mL(-1) after a dose of 800 microg.
Conclusions: Inhaled SAL does not enhance time-trial performance, regardless of dose, and that urine cSAL after exercise is related to dose, demonstrates high variability, and is partially related to hydration status."

Even at 800 micrograms, an order of magnitude lower than a single day's dose of the amount required to produce the anaerobic improvements (and that dosage was repeated for four weeks), it's possible to get very close to the WADA limit. Add in variability, plus the fact that dehydration will artificially elevate the measurement in the urine, and it's clear it's possible to exceed WADA's limit without seeing any performance improvements.

There are a couple more problems here. Metabolization will differ by individual, and by the environment in which it's taken - a fat breathless desk jockey like me is likely to have a different rate from a Tour de France sprinter. Metabolism of salbutamol differs between asthmatics and healthy people too, with the asthmatics showing higher concentrations of salbutamol in urine for the same dosage.

Another thing that's missing is data on the urine concentrations in the subjects who took the massive doses, and showed anaerobic performance improvements. Do they show the same variability of urinalysis data ? What kind of urine measurements were found ?
I suspect their urine would show levels massively higher than the 1000 ng/ml that is currently considered a violation.

Personally I give any endurance athlete the benefit of the doubt in a salbutamol case. A cycling sprinter like Petacchi is a special case, since he could theoretically benefit from the anaerobic performance improvements: but he still has to ride 4-6 hours at moderate to high aerobic pace, just to reach the sprint. Anaerobic performance after this kind of effort has never been tested. Add that to the questions around the current level which is considered a violation, and I think all these salbutamol 'violations' are likely bogus. The potential benefit is too small for the risks.

This 'violation' in particular is nonsense. Even the CAS said, "the adverse analytical finding in this case is the result of Mr. Petacchi simply, and possibly accidentally, taking too much Salbutamol on the day of the test, but that the overdose was not taken with the intention of enhancing his performance. Indeed, it would be an unusual way of attempting to enhance performance to take the prohibited substance after the particular event had concluded."
So.. what is this ? zero-tolerance, as propounded by the imbeciles that propagate the War on Drugs ? It's senseless.

endurance training

After reading through the 99 pages of the letsrun thread discussing Lydiard and Daniels, I realized I had not understood Lydiard's training methods.. another thing that struck me was how similar Mark Allen's protocol is to Lydiard's. (I see the thread is now up to 128 pages, oy, more homework).

The closest thing to a Lydiard training manual appears to be this document, from a lecture tour in 1999. Another reasonable facsimile of it seems to be in Bill Squire's book (coached Bill Rogers and Dick Beardsley among others).

A compare/contrast of Lydiard and Daniels is on page 12 of the thread, and see an outline of Mark's ideas.

Both systems use a repeated cycle of base/sharpening/specific training. Lydiard had a 6-month cycle allowing for two peaks a year, Mark uses the MAF test to determine when to shift the focus. The MAF test seems very close to Lydiards' "time trials", a test that gives the coach the metric and data to fine-tune training.

- Base: Lydiard liked 8-12 weeks, Mark mentions 4 months. Lydiard threw the watch away and asked his runners to run at a pace that left them 'pleasantly tired', but feeling able to do more. Mark gives an exact HR range based on Maffetone's numbers. The HR makes a lot of sense for new athletes who don't have a good sense of RPE, and as a reality check for experienced athletes: personally I think the old-fashioned LSD 'talk test' works fine too.
- sharpening: Lydiard has fairly detailed and specific sections, but he's on record as saying the actual anaerobic sessions don't matter much, as long as the required work is done. Typically about 3 weeks of running economy work, using hill springing and downhill running; followed by 4 weeks of 'anaerobic training', 2 to 4 sessions/week of the basic interval work we all know and love. Before reading the letsrun thread, I had not realized how much drilling/running-economy-specific training was done in the 'hill training' phase.
Mark is a lot less specific, but the principles are much the same:
"high end interval anaerobic training one or two days/week... just like the aerobic training, there is a limit to the benefit .. you will see your speed start to slow down again.. signal that it is time to switch back to aerobic.. Keep your interval sessions to around 15-30 minutes of hard high heart rate effort total."
- race conditioning: Lydiard uses weekly time trials (not race-effort) and short high-intensity intervals, reducing volume but not intensity over the last few weeks. Mark doesn't explicitly detail this stage.

The commonalities are a base of pure aerobic training, a training cycle that repeats the basics over a maximum 8-12 weeks of any one phase, and regular tests at known distances and efforts to measure the results of the training.

Never underestimate how much improvement you can get from consistent aerobic training. There was a great interview with Peter Snell at Runners' World, but it's vanished now. Luckily letsrun has preserved it (about a third of the way down the page).
"Most physiologists are trained on the idea of specificity, and simply can't understand that slow training makes you faster. "
Bear in mind that Dr. Snell is himself a physiologist.

My favorite quote from the letsrun thread:
"Eventually the Lydiard system vanishes, like the state was supposed to under Communism, and the runner just feels it. It is the way musicians do it. Music and running are really the same thing - performance and emotion."
Tom Derderian (himself a fine marathoner)
Another good Derderian quote: "the world is a conspiracy to keep you from training."

out of season 6

The graveyard at Lotzbeuren, immaculately maintained. See the first 'out of season' post below for context..

out of season 5

mere gratuitous prettiness..

out of season 4

I had visions of renting a bike to pootle up and down the Mosel. Apparently the river is unusually high. Here's the bike path.

out of season 3

In the early 90's, those go-go days, the egregious Esther Dyson together with some other overpaid theoreticians, proclaimed 'the overthrow of matter'.

Here it is the Year of our Lord 2008 in a bold new century, and we're still pushing coal laboriously upstream in order to fuel the power stations that move our electrons around. Watching these barges shoving along, it looks like they are going uphill. In several senses they are I suppose, but it's still odd to watch.