Monday, February 27, 2017

Answer: Weather causes pain?

This is tricky. 

This week we've been investigating the connection between the weather changing and aches/pains in the body.  




Is it a real thing when your aged parent complains about the changes in the weather?  

I've often wondered this, and in doing a bit of searching I found that it's not as simple as you might think.  Reminder: Here's was the Challenge for the week--can you find evidence for these?  


1.  Can changes in the weather cause real joint pain? 

2.  Can changes in weather cause other kinds of pain in the body? 

3.  If so, what's the mechanism that causes the pain?  (How can this possibly be?) 



Fair warning up front:  I thought this was going to be a simple Challenge.  I didn't know it would turn out this way!! 

Let's start with a few obvious queries: 

     [ "joint pain" weather ] 

     [ "joint pain" AROUND(5) weather ] 

Looking at the SERPS you'll find a LOT  of documents. There are many web pages about this topic.  But if you notice, while some say it's obvious that joint pain is connected with weather, many of them are skeptical of the claim that joint pain is associated with changes in the weather.  

For instance, the Cleveland Clinic's rheumatologist says that “Some people believe that when you drop the barometric pressure, your air pressure, that sometimes your tissues can swell.”  (Notice the little hedge in there, "some people believe....") 

Then again Weather.com, the Arthritis Foundation, and WebMD all agree with this weather / joint-pain connection. But they also hedge their bets with a "There's no full agreement among scientists that weather causes pain, or if a specific mechanism is at fault..."  

That's a lot of quasi-uncertainty.  

By contrast, Live Science reports on two studies, one published in Pain Medicine, and the other in the journal Osteoarthritis and Cartilage, (both from December 2016) that did NOT find any connection between weather and joint pain.  

What's up with all this back-and-forth?  This is making me suspicious.  Is the story wrong?  Does Weather.com have a vested interest here?  

Part of what's making me worry about this is that the pressure change when a storm front moves in just isn't that much of a pressure change.  

You see, normal sea level air pressure is around 1013 millibars. That's what you're experiencing right now.  But a low pressure system associated with a thunderstorm runs around 1005 millibars, while a high pressure system could be as high as 1040.  

Since people complain about joint pain when the storm is coming in, that's usually a drop in air pressure.  

Let's imagine that the air pressure drops from a normal pressure of 1013 to 1000 millibars.  (That's a real thunderstorm kind of number--the rain is really going to come in if you see a 1000 millibar reading.)  

That's the same air pressure you'd feel if you were about 400 feet off the ground--let's call it 40 stories.  (Check the pressure conversion table to see where that number comes from.)  

That's a tall, but not massive apartment building.  If this were a problem, every time a sensitive person went to the 40th floor, they'd suffer joint pain.  

So I did a quick search for the connection between elevators and joint pain: 

     [ "joint pain" AROUND(5) elevator ] 

This search yields nothing.  Absolutely nothing. Huh.  That's strange.  Is it just a barometric pressure change that could cause pain?  

Okay, how about searching for joint pain associated with flying in a plane.  I tried: 

     [ "joint pain" airplane ] 
     [ "joint pain" pressure change in airplane ]  

and again, I found nothing.  (There are many article, but none of them say anything about joint pain being caused by a change in cabin pressure.)  

I looked up the cabin pressure, and for most planes, it's around 800 millibars.  That's quite a change from 1013 millibars... but there's not much comment about that.  So I'm getting even more dubious.  

So I checked Google Scholar for some peer-reviewed papers on this topic with the simpler query: 

     [ "joint pain" weather ] 

It's not clear this helped clarify things.  

In one study, [1]  
"..Earlier studies, using climate control rooms, indicated that rheumatic symptoms were unaffected if weather conditions were held constant or if only one of the variables temperature, humidity, or barometric pressure were altered...."  

Great.  That makes sense.  But they then go on to say that: 
"... Raising the humidity and lowering the pressure simultaneously, however, led to the appearance of some rheumatic symptoms."  

Okay, interesting.  Maybe you need to change humidity and pressure together to get joint pain.  


Here's another study [2] where the researchers say 
"There is a widespread and strongly held belief that arthritis pain is influenced by the weather; however, scientific studies have found no consistent association. We hypothesize that this belief results, in part at least, from people's tendency to perceive patterns where none exist..."  
And another study [3] where the researchers studied multiple factors (including the appearance of sunspots and the aurora borealis).  THEY found that 1-out-of-6 of their participants were sensitive to something, but they couldn't fit a good model to the weather and pain.  Still, they weakly conclude that it's possible.  

As you'd expect, about every other paper reports a different result.  Yet another study [4] reported that pain was correlated with low temperature, high atmospheric pressure, high humidity for rheumatoid arthritis.  This complicates things, as these folks reported pain with HIGH pressure, not low pressure. Sheesh. 

Another paper [5] says:
Despite anecdotal reports from patients, change in weather factors does not appear to influence the risk of pain exacerbation in persons with knee osteoarthritis. 

And of course, they conclude with that eternally optimistic phrase... 
Additional studies should quantify the association of weather and risk of pain exacerbation in regions with more extreme weather conditions.

FWIW, I kept looking around, and it didn't matter which article I read, one would claim it's a real effect, while the next would say that it wasn't. 

And nobody... not one single paper, article, or book chapter... had anything like a plausible explanation for what would be causing this.  


My conclusions is that what the authors say in that LiveScience article is probably correct:  

But our research suggests this belief [that weather change causes joint pain] may be based on the fact that people recall events that confirm their pre-existing views.
For example, people may take note of pain on days when the weather is bad, but discount the connection on days when the weather is nice and mild, he said. 
Not all experts agree with the studies' failure to find a link between weather and joint pain, however.
"Despite these studies, it is not possible to say that there is no link, especially given how much people report that for them there is a strong link" said Dr. Robert Shmerling, the clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center in Boston.
"It is nearly impossible to 'prove a negative' — there is always a possibility that a particular weather feature does affect a particular type of arthritis in a particular set of people — but so far we haven't figured out if that's the case," Shmerling told Live Science.

In short, it's incredibly difficult to tell what's true here by reading the popular or medical literature.  There is real disagreement about whether it's a genuine effect, or if it's just people noticing the pain and perceiving a pattern of correlation that's not really there.  

My conclusion?  

We need more research.  (But I'm kind of leaning towards "it's not a real thing...")

In these days of falsified news reports and big conflicts in reporting, it's good to remember than this is often the case in less fraught topics as well.  It's clear that the scientists and physicians don't really know what's going on here either.    

Keep searching!  




__________________________________
Citations

[1] Guedj, Daniela, and Abraham Weinberger. "Effect of weather conditions on rheumatic patients." Annals of the rheumatic diseases 49.3 (1990): 158-159. 

[2] Redelmeier, Donald A., and Amos Tversky. "On the belief that arthritis pain is related to the weather." Proceedings of the National Academy of Sciences 93.7 (1996): 2895-2896.

[3] Smedslund, Geir, et al. "Does the weather really matter? A cohort study of influences of weather and solar conditions on daily variations of joint pain in patients with rheumatoid arthritis." Arthritis Care & Research 61.9 (2009): 1243-1247.

[4] Strusberg, Ingrid, et al. "Influence of weather conditions on rheumatic pain." The Journal of Rheumatology 29.2 (2002): 335-338.

[5] Ferreira, M. L., et al. "The influence of weather on the risk of pain exacerbation in patients with knee osteoarthritis–a case-crossover study." Osteoarthritis and cartilage 24.12 (2016): 2042-2047.

2 comments:

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    1. Not this weekend, I'm attending a seminar in Dagstuhl, Germany. But as you can see by the syllabus, I'll be back on Thursday!

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