40 replies to this topic

[SteveNorden]

Perth study finds heart attack chemical in marathon runners
20 Mar 2009

People who run marathons are more likely to have higher levels of a protein linked to heart attacks, according to researchers at the University of Western Australia.

UWA's Associate Professor Daniel Fatovich and UWA Clinical Associate Professor Samuel Vasikaran, a biochemist, are two of the co-authors of a paper published in the Medical Journal of Australia, which studied 92 runners who competed in the 2007 Perth Marathon.

Dr Fatovich, an emergency medicine specialist at Royal Perth Hospital, said elevated levels of the heart protein troponin were commonly used as an indicator when diagnosing a heart attack.

"We found raised troponin levels in a third of those who completed the marathon, with the strongest predictors being weight loss and an increase in creatinine levels. Creatinine is a measure of kidney function," he said. "This suggests that the kidneys are working hard to clear the extra troponin from the body.

"What was interesting was that the marathon runners were not adversely affected by these elevated levels of troponin – it didn't seem to cause any health issues for them. It seems that in a healthy exercising population, troponin is routinely released from the heart muscle after periods of increased demand on the heart."

Of the 346 entrants in the marathon, the researchers enrolled 92 runners (27 per cent), of whom 88 (96 per cent) finished the race and took part in the pre and post-race surveys and blood tests.

Of those who took part in the study, 71 per cent were male while the mean age was 43 years and mean body mass index (BMI) was 24.1. They had trained on a mean of 4.5 days per week, running a mean of 60km per week in the three months before the race.

They had previously completed a mean of 9.5 marathons, with one participant running his 100th marathon and 26 per cent were competing in their first marathon.

(Source: University of Western Australia: Medical Journal of Australia: March 2009)

From: http://www.virtualme...asp?artid=13365

[undercover brother]

thanks steve: troponin 'leaks' in athletes is old news.
there have been a few other studies showing the same thing over the years and its hard to know the significance of it.
there have been a few CR threads about it over the years as well as more recent data highliting abnormal (if i remember correctly) right ventricular heart function in the post marathon phase.

[walker1st]

SteveNorden, on Mar 21 2009, 09:18 AM, said:

Of those who took part in the study, 71 per cent were male while the mean age was 43 years and mean body mass index (BMI) was 24.1.

in the old days, somebody with BMI 24 would not be called or labeled marathoner

and here 24 is a mean.

the study should perhaps be called :

bunch of overweight undertrained people are full of chemicals after forced to complete 42km.

[brizza]

the ones with raised troponins were just showing off
ay oop lad,in those days wen we ran marathons we'd 'art attacks and it naver stopped oos,not one bit,yoong people today wouldn't believe it....

[pharlap]

walker1st, on Mar 21 2009, 01:19 PM, said:

in the old days, somebody with BMI 24 would not be called or labeled marathoner

and here 24 is a mean.

the study should perhaps be called :

bunch of overweight undertrained people are full of chemicals after forced to complete 42km.

Couldn't agree more

[bruncle]

Important question re: sampling methodology..Did they stratify based on training volume? Previous studies have shown that people who train over 80kpw prior to the marathon do not exhibit any worrying markers, while the comparatively untrained have raised troponin levels and other danger signs, which remain elevated for two weeks after the event.

[millymoo]

troponin is a marker that indicates muscle damage. Therefore, most people who have put their muscles under strain for a period of time will show raised levels of troponin.

There are different types of troponin and only one of these is exclusive to cardiac muscle.

This study, does then need more detailed analysis to find the true significance for marathon runners.

[TechGirl]

Horses don't suffer from "heart attacks" as humans do and they too get elevated troponin levels after competing in endurance rides. The majority of these horses are extremely fit and certainly would not be considered over weight. We do see increases in skeletal muscle enzymes in response to exercise that have nothing to do with muscle pathology. Such markers are not always a clear indicator of pathology.

TechGirl

[charlieboy]

walker1st, on Mar 21 2009, 01:19 AM, said:

in the old days, somebody with BMI 24 would not be called or labeled marathoner

and here 24 is a mean.

the study should perhaps be called :

bunch of overweight undertrained people are full of chemicals after forced to complete 42km.

BMI of 24 is not overweight it is in the "healthy" range for adults. 178cm at 75kg is 24.

"Undertrained" why do you say that? The "mean" is 60k/week but that could mean they did 30-40k/week in the first few weeks building up to 80-90k in the final few weeks.

They had also done an average of 9.5 marathons. Hardly average.

Why don't you check your facts first?

[Swaggers]

The more research they do in this area the better. There was one test where the winner of an overseas bike race had the highest levels of troponin. No ill effects. I posted it on CR once. Ach Tung people.

Swagger.

[orlando]

The abstract can be read here. The only significant correlation seemed to be with creatinine, not training volume or anything else. I think it would be hard to work out whether the higher troponin levels reflected actual cardiac damage, or just less effective renal clearance.

[walker1st]

charlieboy, on Mar 23 2009, 05:39 PM, said:

BMI of 24 is not overweight it is in the "healthy" range for adults. 178cm at 75kg is 24.

"Undertrained" why do you say that? The "mean" is 60k/week but that could mean they did 30-40k/week in the first few weeks building up to 80-90k in the final few weeks.

They had also done an average of 9.5 marathons. Hardly average.

Why don't you check your facts first?

why don't You think about the facts first second and third ?

24 is considered ok by western medical profession as the range for typical western population

that aproach has nothing to do with reality, only reflects the western culture.


the 60km per weak as an average means that while some runners did the 100km week
some did maybe 20-30 km weeks.

average 9.5 marathons could also mean, that some were teh marathon colectors having done 100+ marathons, some have done 20 marathons ages ago, but nothing last few years etc.

unless You are bodybuilder, 75 kg is overweight for 178 cm male

although by Your criteria it can be ok

[funrunner63]

walker1st, on Mar 23 2009, 03:16 AM, said:

unless You are bodybuilder, 75 kg is overweight for 178 cm male

I don't do weights, I weigh 75kg and am 178cm, my bodyfat tonight was 15.5%, now I feel fat....

Edited by funrunner63, 23 March 2009 - 07:21 PM.

[DoggieDoctor]

Good to see there are so many educated people in this group. Major problem is the time of sampling. Of course you are going to have an elevated creatinine. Decreased hydration and decreased glomerular filtration rate (GFR). If you slap your muscles around by running and you end up with an elevated CPK (Creatine phosphokinase) or CK to the younger ones here, it doesn't mean you have toxoplasmosis. I know stupid analogy but if you formulate a protocol for testing anything, and then add a biometrician, you can get almost any results you want.

DD

[DrJH]

charlieboy, on Mar 23 2009, 05:39 PM, said:

BMI of 24 is not overweight it is in the "healthy" range for adults. 178cm at 75kg is 24.

"Undertrained" why do you say that? The "mean" is 60k/week but that could mean they did 30-40k/week in the first few weeks building up to 80-90k in the final few weeks.

They had also done an average of 9.5 marathons. Hardly average.

Why don't you check your facts first?

A BMI of 24 might be considered 'healthy', but it is fat if you call yourself a marathon runner.

80-90k a week is still undertrained for a marathon runner. 1500 runners do that much.

Running 4 and a half days a week strikes me as pretty slack preparation as well.

9.5 marathons. I bet all of them were slow!

It would be interesting to know what sort of troponin levels well prepared marathon runners had, as opposed to these 'weekend warriors'.

[orlando]

I'm not going to get into the arguments as to what makes a "real" marathoner, because why does it matter? This is the Perth marathon we're talking about - it's not a big event with huge prize money that attracts lots of elites, so I'd argue that the field probably fairly accurately represents the majority of people out there running marathons.

And while studies on elite athletes are interesting from a physiological point of view, it's probably more beneficial to study what effects such events have on the "average" punter.

[undercover brother]

what none of these studies show is what these troponin leaks mean.
ie. does it mean they have an increased risk of coronary artery disease.
the problem is if you test everyone for CAD some will get complications.
eg. do a stress echo get a false positive or equivocal result do you do an angiogram on everyone with the inherent complications?
guess it would be nice to think that everyone would have a negative non-invasive test eg. a stress echo or ct angiogram and that all those with positive results go on to find CAD that otherwise would've been picked up later at an inopportune moment... but...

edit: translation...
if you got 1000 people with troponin leaks after a mara and 1000 people who didnt.
and did a test sometime later to look for blocked arteries.
would the people with troponin leaks have worse arteries and be more at risk of heart problems in years to come?
this is what we dont know.

Edited by undercover brother, 24 March 2009 - 04:10 PM.

[Steve 'The Footman']

Pointless and poor methodology with this study. Done many times better before.

As a 75kg 178cm runner myself I certainly think I have some blubber to lose. Despite this I will be trying to complete my 20th marathon this year at Gold Coast with an average weekly kilometre rate of about 60km /week with a maximum just under 100kms.

BMI's are a generalisation. There would be many people with a BMI of 24 who should not lose weight. I am not one of them as my lean muscle mass is still a lower percentage then it should be (sounds better than saying I have too much fat) . The BMI scale is also a continuum. There will be more people who are actually overweight at BMI 24 then BMI 23. I would certainly agree that the acceptable range for healthy is too high.

Regardless, I think we should be encouraging more overweight people to do marathons. Despite the raised troponin levels they are still better off then sitting at home getting fatter in their lounge chairs. You can train for a marathon successfully on 3 to 4 runs a week. As long as you are realistic about your goals and do the right sessions you should be safe. Not everyone has the lifestyle that allows them to dedicate themselves completely to the marathon. It is still a great challenge and accomplishment at any pace.

[undercover brother]

Steve'The Footman', on Mar 24 2009, 06:59 AM, said:

Pointless and poor methodology with this study. Done many times better before.

considering fatovich is a colleague i decided not to be so harsh
all this BMI talk?
have a look at the objective of the paper: To determine the prevalence of elevated troponin levels after a marathon, and test for an association with reduced renal clearance.
they achieved this.
this being said anyone (including the authors) who has done a troponin on a patient with renal impairment would already know this.
though it is nice to prove in healthy subjects with hydration issues and 'acutely' reduced GFR...
now if they had done a stress echo on everyone that would've been a talking point.
old news.

Edited by undercover brother, 24 March 2009 - 07:28 AM.

[charlieboy]

DrJH, on Mar 23 2009, 11:45 AM, said:

A BMI of 24 might be considered 'healthy', but it is fat if you call yourself a marathon runner.

80-90k a week is still undertrained for a marathon runner. 1500 runners do that much.

Running 4 and a half days a week strikes me as pretty slack preparation as well.

9.5 marathons. I bet all of them were slow!

It would be interesting to know what sort of troponin levels well prepared marathon runners had, as opposed to these 'weekend warriors'.

Not all of us are "elite" runners like yourself DrJH.

I have a friend who is 183cm and 85kg (BMI of 26). This "fatty" ran a 2:44 marathon last year and did a sub 3:50 six foot track. I would guess his body fat levels to be in the 5% range. Not all of us are built like marathoners because not everyone can win the genetic lottery.

Some marathon training guides emphasise the weekend long run. 35k on sunday. A midweek long run of 20k, two 15k days and an interval session of say 10x400 would give you just 90k but would be reasonable preperation for the average marathoner with a full time job and wife and kids. Believe it or not most runners have a life outside running.

Why ridicule the average marathon runner who (by your standards) is slow? He/she is out there busting a gut to achieve personal goals which may not seem like much to you but are worthy goals nonetheless.

The top marathoners are tested every year. They have scientists prodding and poking them all year round. I am sure there is tons of data on them regarding troponin levels, which is maybe why this study was based upon average runners.

[DrJH]

charlieboy, on Mar 24 2009, 09:38 AM, said:

Not all of us are "elite" runners like yourself DrJH.

I have a friend who is 183cm and 85kg (BMI of 26). This "fatty" ran a 2:44 marathon last year and did a sub 3:50 six foot track. I would guess his body fat levels to be in the 5% range. Not all of us are built like marathoners because not everyone can win the genetic lottery.

Some marathon training guides emphasise the weekend long run. 35k on sunday. A midweek long run of 20k, two 15k days and an interval session of say 10x400 would give you just 90k but would be reasonable preperation for the average marathoner with a full time job and wife and kids. Believe it or not most runners have a life outside running.

Why ridicule the average marathon runner who (by your standards) is slow? He/she is out there busting a gut to achieve personal goals which may not seem like much to you but are worthy goals nonetheless.

The top marathoners are tested every year. They have scientists prodding and poking them all year round. I am sure there is tons of data on them regarding troponin levels, which is maybe why this study was based upon average runners.

I'm not trying to ridicule slow marathon runners - I'm one myself! Women have run faster times than me.

We all have our excuses with regards work, family, etc. Like most people I just prepare the best way I can. You describe me as 'elite', but I've never had a scientist prodding me! I wouldn't have a clue what my troponin levels were.

I just think it would be of more use if we new what well trained runners' troponin levels were. Maybe more training is protective? Maybe they'd be higher.

[Nate]

Without 'weighing' into the debate about the BMI of a marathoner, I have just one thing to say:
I'd rather die of a heart attack out on a training run (or race) then stay at home and eventually die of old age. There's a difference between living life and being alive!

Nate

[undercover brother]

DrJH, on Mar 24 2009, 09:38 AM, said:

I just think it would be of more use if we new what well trained runners' troponin levels were. Maybe more training is protective? Maybe they'd be higher.

protective against what?
we dont know what troponin leaks mean edit: in marathon runners.
maybe its a good thing?

Edited by undercover brother, 24 March 2009 - 01:55 PM.

[Swaggers]

Quote

we dont know what troponin leaks mean.

Why not?

I am a little confused as to why there is a difference between an elite athlete and a hack. If a hack leaks troponin and there is no long term damage, isn't that a good thing for elite runners who also leak troponin and think it is the hard-core training and racing that is causing the leakage and thus may be diagnosed as having a heart attack, or have concerns that they may be damaging their heart. The way i see it the study suggests that troponin leaks don't necessarily suggest heart attack but could be normal reaction to hard exercise - regardless of level. Regardless because an elite running at say 3:10 pace and a hack running at say 4:30 minute k will both be exerting their heart to a similar extent. If there is a noticeable difference between the highly- trained athlete and others - then whyis that so and what is the significance?

Quote

The top marathoners are tested every year. They have scientists prodding and poking them all year round. I am sure there is tons of data on them regarding troponin levels, which is maybe why this study was based upon average runners.

Will you please direct us to the ones that examine their troponin levels and the significance of any in a runner's blood test. Thank you.

Swagger.

Edited by Swaggers, 24 March 2009 - 12:04 PM.

[undercover brother]

Swaggers, on Mar 24 2009, 11:55 AM, said:

The way i see it the study suggests that troponin leaks don't necessarily suggest heart attack but could be normal reaction to hard exercise - regardless of level.

i think thats more an assumption from all the previous papers quoted on this site rather than a suggestion from this paper.
this study looks at its objective which i listed above.
from the abstract it also looks at ischaemia-modified albumin (which was elevated) but not an ecg or an echo.

Edited by undercover brother, 24 March 2009 - 12:41 PM.

[FakePlasticTrees]

undercover brother, on Mar 24 2009, 07:24 AM, said:

now if they had done a stress echo on everyone that would've been a talking point.

Stress test on a first time marathoner straight after completing? You'd probably kill most of them

[undercover brother]

cheeky bastard
that can be the extra 8km at the canberra 50

[Swaggers]

Quote

"What was interesting was that the marathon runners were not adversely affected by these elevated levels of troponin – it didn't seem to cause any health issues for them. It seems that in a healthy exercising population, troponin is routinely released from the heart muscle after periods of increased demand on the heart."

UCB. I am totally lost. I haven't seen the papers that examine troponin's in any athlete -elite or hack -quoted on this site. I was always under the impression that any troponin in the blood was of great concern. The IMA method is all news to me. I am just a dumb-arsed runner with a few concerns. It seems that IMA is the new best way of determining that the heart muscle hasn't gotten enough blood (or blood that is damaged?)?

Swagger.

Edited by Swaggers, 24 March 2009 - 01:13 PM.

[DoggieDoctor]

DrJH, on Mar 24 2009, 09:38 AM, said:

I'm not trying to ridicule slow marathon runners - I'm one myself! Women have run faster times than me....

Wish I had the guts to say something like that! Mind you if I could actually beat some of them I'd probably have the guts.

DD

[undercover brother]

Quote

UCB. I am totally lost.

hmmmm let me put it this way...
this paper wont stop me running.

Edited by undercover brother, 24 March 2009 - 01:32 PM.

[Leofisio]

walker1st, on Mar 23 2009, 08:16 PM, said:

the 60km per weak as an average means that while some runners did the 100km week
some did maybe 20-30 km weeks.

average 9.5 marathons could also mean, that some were teh marathon colectors having done 100+ marathons, some have done 20 marathons ages ago, but nothing last few years etc.

In a study with 97 individuals, I believe that the average is quite accurate, if the researcher reported the mean not the median, I would assume that the extreme observations (outliers) are not common as Rudi is saying...

Maybe the researcher is wrong and his sample is inadequate, but he sampled 27% of the whole population (population= people running a specific marathon). This is quite a lot!

I am not defending anyone here, but Rudi criticises research all the time without basis for it...

Leo

[walker1st]

Leofisio, on Mar 25 2009, 05:53 AM, said:

In a study with 97 individuals, I believe that the average is quite accurate, if the researcher reported the mean not the median, I would assume that the extreme observations (outliers) are not common as Rudi is saying...

Maybe the researcher is wrong and his sample is inadequate, but he sampled 27% of the whole population (population= people running a specific marathon). This is quite a lot!

I am not defending anyone here, but Rudi criticises research all the time without basis for it...

Leo

I am glad to disagree as I see it very differently.

It allways comes to point, that half the samlew is above and half teh sample bellow any value.

so half teh sample is above 24 or runs less than 60km etc.

so half the sample is overweight and undertrained.

yet it can be this half of the sample giving the reading of increased chemicals and whatever else.


slightly better aproach to research ( not that any is really needed for healthy happy life)

would be to split the sample to 2 halfs or better to 3 thirds :

these well bellow the 24, those around the 24 and those well above the 24 (BMI) for example
and look separately at the chemicals mentioned in each group and compare it,
and that do teh split into 3 groups for any other factor ( those well bellow 60k per week etc) and again compare the cross results.


studies are good as a discussion topics and manipulated studies are good for political purposes and population control agenda,

but otherwise ?

any usefull study is banned from publishing, and even if it is leaked nothing from it ever comes good

Royal commision anybody ?

[Leofisio]

walker1st, on Mar 25 2009, 09:01 AM, said:

I am glad to disagree as I see it very differently.

It allways comes to point, that half the samlew is above and half teh sample bellow any value.

so half teh sample is above 24 or runs less than 60km etc.

so half the sample is overweight and undertrained.

yet it can be this half of the sample giving the reading of increased chemicals and whatever else.


slightly better aproach to research ( not that any is really needed for healthy happy life)

would be to split the sample to 2 halfs or better to 3 thirds :

these well bellow the 24, those around the 24 and those well above the 24 (BMI) for example
and look separately at the chemicals mentioned in each group and compare it,
and that do teh split into 3 groups for any other factor ( those well bellow 60k per week etc) and again compare the cross results.


studies are good as a discussion topics and manipulated studies are good for political purposes and population control agenda,

but otherwise ?

any usefull study is banned from publishing, and even if it is leaked nothing from it ever comes good

Royal commision anybody ?

You are a smart guy Rudi,

This is called "normal distribution" and reflects the REAL population of runners (some very fit and lean, some half way, and some unfit and fat).

The problem of spliting in three groups is lack of statistical power, for every subgruop you split you have to quadruple the sample size. This means that the author should recruit 400-500 runners rather than 97. Which is sometimes impossible to do it.

To publish an underpowered study is as useless as don't publish anything.

I just don't think fair to criticise the author without any clear reason. Research is a hard thing to do... and it is easy to criticise without reason.

Leo

[orlando]

Rudi, if you look at the abstract that I linked to above, they more or less did what you're suggesting. When they analysed the results they did look to see if there was any relationship to BMI, training time, etc... The only significant correlation was to creatinine.

[walker1st]

Leofisio, on Mar 25 2009, 09:34 AM, said:

I just don't think fair to criticise the author without any clear reason. Research is a hard thing to do... and it is easy to criticise without reason.

Leo

Leo I am not critical ofthe author of teh study at all.
I am not even respondibng to study as such

I am responding to discussion about :

who is marathoner and who is not,

is the 24 BMI overweight or not and pointingto fact that even if the 24 is accepted as OK, it still leaves half the sample as overweight etc etc.

If we talk about the study - such a study does nothing to help anybody, no runner would modify the training or lifestyle of racing as a result of it,

coaches would not change their systems

coaching eductaion guidliness would not be changed and the coaching seminars would remain exactly the same

the runners or wider population will not even gain anything as far as general eductaion goes,
whoever reads the study might just be left more confused and perhaps more scare.

spreading the fear seems to be the cultural fenomenon, masterfully guided by pollies.

I could not see any practical usable effect resulting from this and any similar studies.

Do You ?

[Leofisio]

Not in the case from this specific study.

Physiological biomarkers are sometimes useless and this study is not likely to change anything in terms of training, etc. However new studies could get information from this and find something more useful, that is the way research works.

Lots of new ideas from effective treatments were discovered from "useless" studies like this.

I like studies that sample individuals with a random sample (such as this study)... studies that just analyse professional runners will generalise their results to professional marathoners (and almost no one from coolrunning would "fit" on the data).

I think we are both cool now

Have a great day!

Leo (finished my PhD today!)

[walker1st]

Leofisio, on Mar 25 2009, 10:52 AM, said:

Leo (finished my PhD today!)

congratulation

despite this, You are still cool guy

[Swaggers]

Quote

Have a great day!

Leo (finished my PhD today!)

Leofisio. Congratulations. I am told it is a rigourous and demanding challenge. Thanks for your input to CR.

Cheers,

Swagger.

Edited by Swaggers, 25 March 2009 - 10:03 AM.

[undercover brother]

dr leofisio!

[Leofisio]

Thanks guys!

Now I have some time to train for my second marathon!

Leo

[brizza]

Leofisio, on Mar 25 2009, 10:52 AM, said:

Not in the case from this specific study.

Physiological biomarkers are sometimes useless and this study is not likely to change anything in terms of training, etc. However new studies could get information from this and find something more useful, that is the way research works.

Lots of new ideas from effective treatments were discovered from "useless" studies like this.

I like studies that sample individuals with a random sample (such as this study)... studies that just analyse professional runners will generalise their results to professional marathoners (and almost no one from coolrunning would "fit" on the data).

I think we are both cool now

Have a great day!

Leo (finished my PhD today!)

yay well done,dr leofisio