I hadn't replied to this originally because I did not know what I could say that would make a difference despite what I was reading from pretty much every respectable source I could find. But since this is bumped up again...
<div class="FTQUOTE"><begin quote><div class="FTQUOTE"><begin quote>A basic definition of why this occurs with those who have CF, according to the CFF website is "A defective gene and its protein product cause the body to produce unusually thick, sticky mucus that obstructs the pancreas and stops natural enzymes from helping the body break down and absorb food."</end quote></div>
One study I read about indicates that people with CF don't produce "too much" mucus, and indicated that, instead, they produce too little and that all the gunk in their lungs is phlegm (ie infection), not mucus. This second explanation fits better with my experience and makes more logical sense to me. So, since I consider this common definition of the problem to be in error, I don't believe it explains anything about pancreatic insufficiency.</end quote></div>The CFF quote didn't say 'too much' there- they said unusually thick, sticky mucus. This is caused by the genetic defect that causes CF. This is NOT limited to the lungs. This defect is present throughout the body- thus affecting exocrine cells in many parts of the body, resulting in these thick, sticky secretions.
'Insufficiency' is defined on 'wordnet' as "(pathology) inability of a bodily part or organ to function normally." With CF patients, it's a physical chain of events, as in when there is scarring or damage done to the pancreas, delivery of pancreatic enzymes to the intestines is affected. When not enough gets there, there is an insufficient amount in the intestine to properly digest the food. I don't know what the mystery is there: abnormal secretions caused by CF damage the pancreas, enzymes don't reach intestine, food doesn't get properly digested.
We don't have to guess as to whether this is happening, either. This can be directly observed in several ways- by physically testing the stool either for the presence of pancreatic enzymes or for undigested fat, or by scoping & examining the pancreas, etc. These are medically accepted tests. Very basic overview of these tests: <a target=_blank class=ftalternatingbarlinklarge href="http://www.labtestsonline.org/understanding/conditions/pancreatic_insuf-2.html">Tests for Pancreatic Insufficiency</a> . I can't explain everything on a molecular level as you ask... I am not a scientist. But I do understand what I hear from my child's drs, and what I read from many respected sources and it all says pretty much the same thing; there doesn't seem to be much controversy about this topic at all. If there is, the studies are few and far between, compared to the ones that are generally accepted to the CF medical community.
<div class="FTQUOTE"><begin quote>This second explanation fits better with my experience and makes more logical sense to me. So, since I consider this common definition of the problem to be in error</end quote></div>I quoted a portion again from your post just to make the point of why I hesitated to reply earlier... it seems that the only studies you would want are ones that will support your experiences and beliefs, and will find fault with others even if they have studied proof behind them or wide support within the CF community.
added note: there is a different disease, called <a target=_blank class=ftalternatingbarlinklarge href="http://www.shwachman.org/">Shwachman-Diamond Syndrome</a>, where PI is present during childhood that for some is reversed during adulthood. HOWEVER, the cause of the PI is different than that of CF.
