Asthma increases risk for COPD 17-fold?

[LowMac]

The following is a short quote from the About.com Asthma site. The guide seems to have her research studies well reported. Not very comforting information for those of us who have asthma, regardless of cause (in my case GERD is the main-contributor if not the direct cause).

What do you all think about this concerning information?

"In a 20-year, follow-up study published in Chest, compared to non-asthmatics, patients who had asthma had a 10-times-higher risk for acquiring symptoms of chronic bronchitis, a 17-times-higher risk of receiving a diagnosis of emphysema, and a 12.5-times-higher risk of meeting criteria necessary to diagnose COPD. This was even after adjustments were made for smoking history and other potential confounders. So, although asthma and COPD are distinct entities, and have different physiological features and risk factors, having asthma is significantly associated with an increased risk for the development of COPD."

A "17 times higher risk for COPD?" - this is a huge number. I know because I see medical statistics often and even a 4 times higher risk is significant. After weeks of search, I'm surprized to just now be finding this information.

Thanks for any input that might be offered.

[LowMac]

Another set of really great statements, thank you for them.

As you and I have both mentioned, it can be frustrating at times when studies or sets of medical information of any kind are diametrically opposed but in most cases it is simply a difference regarding specific factors.

I'll add one more example, in light of your new comment, which is really appreciated.

My own case of adult onset asthma in my late - 40s (had it as a child but not for many years), is almost certainly a direct cause of my GERD. I'm not a smoker and have no obvious allergies, although it's possible I have some food intolerances that act similar to allergens.

I started searching on the GERD and asthma connection and it is very well established as not only a contributor but a "cause" of asthma. While doing the search I came across a Mayo Clinic page stating that GERD may be a cause of COPD in some people.

Quote: "GERD can make COPD worse and may even cause it in some people."
link: http://www.mayoclinic.com/health/copd/DS00916/DSECTION=risk-factors

I decided to email a respiratory specializing hospital (National Jewish Health Center), asking them a question about peak flow meters and about GERD being a "cause" of COPD and they straightforwardly stated that it is not a cause of COPD but a well confirmed cause of asthma.

Here is a quote from that email they sent back to me:

"There is a well know group of individuals for whom peak flow meters don't work. I am not worried about COPD since you have no smoking history. GERD does not cause COPD but is a well known asthma trigger. I hope you are on medication for your asthma. I would not worry about the peak flow meter. Your physician should do spirometry or pulmonary function testing which is much more accurate. Good luck.
Please feel free to email again with further questions."

So...here again, another contradictory bit of info, however, despite this, I truly appreciate both medical entities and I have benefited from their sources many times over. I will just continue to do the best I can in balancing all of the information I find on a given subject but I will continue to stick to the best possible sources.

Thanks again, everyone.

[987931]

You pose the question:

"If age didn't matter a great deal, does this mean that folks even in childhood, whose asthma remains persistent throughout the years of their lives, also develop these more serious obstructive lung diseases withing about 20 years?"

I don't know the answer to this. However, people being more almost invariably means that within some group (taken to be representative of a larger population, such as all asthmatics), there is a higher proportion who develop something--here COPD.

A general point is that the kinds of studies we're talking about don't establish clear causal factors and combinations of factors. We could look at the whole thing the other way around. Of those people who have COPD in some form at some stage in their life, how many would have showed signs of asthma at an early stage in life? I am simply no expert. I wouldn't be surprised if many, most or all did. If so, it's not surprising that researchers would find increased "risks", because they'd be focusing on a group (those with asthmatic symptoms) that is a subgroup of the other (those who have developed COPD). If true, the question is really still: what factors underlie the development of COPD?

Again, I stress that I don't know. Perhaps there is something about asthma that predisposes or can contribute to the development of COPD. The main point is that these kinds of studies can be pretty confusing.

I'll give an example that is familiar to me. I know someone who had a premature baby at around 25 weeks. Now, the proportion of those born at such an age who develop normally is, from memory, relatively low (perhaps a 25%). In the case I'm talking about, the child is absolutely fine, apart from some lung issues: basically, a very normal child years later. What they don't do is break down the proportions. There are many factors that cause premature birth that also contribute to developmental problems (obesity, smoking I think?? ... I don't remember the actual factors but you get the point. It may be that if you are born this prematurely without any other risk factors, then you have a good chance of relatively normal development. It's the nature of research involving statistics. Terms like "risk" are ambiguous and in my view, quite often used intentionally in that way. I don't mean that peopel are trying to hide things; I just mean that people try to present research in the most convincing way possible. It doesn't go down well with journals if researchers confess up front: oh, but we didn't have data on x, y, z .... so take all of this with a large pinch of salt. As you say, it's good that the research is done. It can be frustrating that it's not done better, not contextualized better and so forth.

[LowMac]

I don't mean to harp on this study I posted the thread about but I would have also liked to have known the average ages of the respondents/participants.

If for example the 3,099 "adults" studied, inlcuded anyone of adult age, for example, ages 18, 21 or 25, did these younger folks also have these 10-fold, 12.5-fold and 17-fold chances of developing types of COPD?

If age didn't matter a great deal, does this mean that folks even in childhood, whose asthma remains persistent throughout the years of their lives, also develop these more serious obstructive lung diseases withing about 20 years?

I think I've expanded enough and not meaning to beat a dead horse but I've seen lots of information that varies widely between med research groups, including asthma statistcs. Some can be published the same years but statistics of how many Americans suffer asthma can vary by 5 million from one info site to the next (i.e. 17-million versus 22-million - a huge variance).

Here's a quote from the Wkipedia page on asthma (I realize they are not a medical cite but glean all their information from reputable medical sources:

"In 2005 in the United States asthma affected more than 22 million people including 6 million children."

This means that far more adults suffer asthma than do children (over 3 and 1/2 times as many adults). Some of the sites I have searched however, left me the impression that asthma is more common in children but has to do with the "missing info" I've been refferring to.

That's why I always confirm any information I search on medical subjects, with lots of different reputable sources. The particular study this thread is about however stumped me more than any info I've yet search on a particular subject. I can definitely move on from it but did want to give getting more details on it a good try.

Thanks to both of you for the input, it is sincerely appreciated.

[LowMac]

Sorry, meant to also give direct link to it.

Here>> http://www.managedcaremag.com/supplements/0507_obstructive/MC_0507_obstructive_suppl.pdf

(See page 9 of the symposium-article group)

[LowMac]

Here's one medical research group who has a lengthy disertation on asthma and COPD and the below direct quote from it by the author of the particular article citing the same research (NICOLA A. HANANIA, MD), is the same info I found on lots of other medical research cites. None of the cites I went-to expanded any further on the sudy, other than to say "even with adjustments made for smoking". The other details were left out but nothing I personally can do about it. I'm the one who expressed wishingthose "gaping holes" were filled in.

If you know how to do online search, please do try to find a version that's expanded and with more detail. I'll be the first to thank you for it if you can post it here. ...Thanks.

(Based on the proceedings of a satellite symposium held in conjunction with the Academy of Managed Care Pharmacy’s17th Annual Meeting and Showcase, in Denver, on April 20, 2005) --- Medical Education Reearch, Inc. - Supported by an unrestricted educational grant
from GlaxoSmithKline

QUOTE:

"A recent epidemiologic study comprising 3,099 adult
subjects suggests that asthma might indeed be a risk factor
for the future development of COPD. Results from
this long-term, cohort study conducted in Tucson,Ariz.,
showed that the two diseases developed
markedly similar characteristics over the
course of 2 decades.Compared to those with
inactive asthma, patients with active asthma
had a tenfold risk of acquiring symptoms of
chronic bronchitis, 17 times the risk of being
diagnosed with emphysema, and 12.5 times
the risk of meeting diagnostic criteria for
COPD (Silva 2004)."

[caregiver222]

With due respects, you have never cited a credible study. Only hearsay excerpts from a website.

The information is interesting but there are lots of missing pieces.

[987931]

Yes, there tend to be contradictions in the research with this sort of thing. Researchers are most certainly human, and they're dealing with complex sets of relationships, making it hard to separate out things. You're probably right that the researchers won't be available (or inclined) to go on the record exapnding on the findings. If they worked with a particular group to do the research, it could be worth contacting the group and the researchers, but you're probably right ...

[LowMac]

Thanks for that - a very interesting take and appreciated.

My suspicion is that the same researchers involved in the study, would not be available for direct comment on it but I may attempt to do so, just to see what might result.

As mentioned in my other posts above, studies can be in varied degrees of contradiction with eachother.

For example, I have seen other studies state to-the-effect: "we do not believe asthma becomes COPD or that COPD becomes asthma".

Medical researchers are human like the rest of us. They can make mistakes and disagree among eachother. Still, I'm proud to see the vast progress in so many areas and that they continue to wittle-away at these common diseases.

Thanks again for the reply.

[LowMac]

To expand on my above post, I did find slightly more information at the WebMD site, regarding these statistics I first found at the About.com Asthma Guide site but still there is a great deal of detail still missing. I then found the original medical study abstract and sure enough the statement in the original research article was there. It states in regard to the very high risk of COPD in asthma patients, that "even after adjustments were made for smoking history and other potential confounders" was in the abstract.

This kind of gives the impression that they are saying that smoking was not a relevant issue in that particular study. The original also didn't include the wording that the WebMD article includes that says the risk of developing COPD in asthma patients is "later in life". I have no idea if these means when a person reaches senior-age years or if age makes no difference.

There is however a study WebMD cites titled "Childhood Asthma Linked to Risk of COPD" and in this one, they state that the study showed that that risk for COPD was increased "32 times" in children with severe asthma (Wow!), who developed COPD 50 years later (obviously in their 50s or 60s). There was however no mention of how many were current or previous smokers. That's an extremely important detail that one would think they would include (no offense to WebMD I appreciate their site).

I think these medical researchers are certainly doing their best in advancing knowledge and treatments and thank God for them! It is however, a bit frustrating, as mentioned in my first post, to not see more specifics in the abstracts and even in the full documents. If they can go the extent of such studies, I personally would love to see every possible detail included for best-possible perspective." the devil is in the details" so-to-speak.

Thanks again.