On Nov 29, 2:31 am, gvk2...@yahoo.com wrote:

OK,  for that perhaps one person in 20 who found this subject
interesting.
I received a reply from one of the several researchers who did this
study which appeared recently in JAMA.

I won't use his name,  but here is some of what he said in a informal
email----
--------------------------------------------------------------------------------------------
Our reference group was BMI <25.  The typical guy in that category
had a BMI around 23.  Thus, you can't look at what is typical in the
US or even our study for what PSA should be.  Rather it is the
reference group.  Thus, the difference between you (19) and our
reference group (23) is actually quite small.  Thus, any PSA
concentration would be slightly - approx 5% give or take.  Not
anything that I would worry about.
---------------------------------------------------------------------------------------------

Just a note here from me.  In their study, the reference group BMI was
about 23.  IF you read data on typical American males in the 40 to 70
age group in 2006 I'm sure you will find the average BMI is well above
23.   I recently read that 59% of adult men were BMI of 25 or
greater.  Thus I would suspect that the true typical BMI upon which
the general PSA threshold levels (4.0) have been set are some where in
the BMI 26 to 28 range, which is well above the approximate 23 in the
reference group used in this study.  Now, to incorporate a BMI of say
27 as a reference in your thinking, would involve lots of assumptions
and calculations about which I could only guess.  But I think you get
the concept that there seems to be some need for adjustment when
comparing men with BMI's of 19 versus those with 26 to 27 or even 35,
however slight that adjustment may be.  On the other hand, how many
men have been subjected to biopsies on the basis of an extra .1 or .2
in their PSA?
Obviously acceleration is a very important factor in any level of PSA
which may well override the absolute PSA level.

So a person with a BMI of perhaps 19.0 might, and I repeat "might",
make a adjustment to their PSA of perhaps 5%,  in a downward
direction.   Thus a rather skinny BMI patient might, for their own
thinking, might adjust their threshold 4.0 PSA to a 4.2 PSA for a
comparative basis to a person with a BMI of 23...  remember it said
"approx 5%, give or take".
This stuff is very preliminary and would need to be repeated in more
studies.
Now, the researchers in this study are making NO such claims or
adjustment suggestions regarding skinny folks..  They only spoke to
the case of those individual who were obese, BMI 30 and 35 etc.
Those folks may well need to make a adjustment downward in their 4.0
threshold of 11 to 20 percent.

So from my thinking, you could have a 2 men, one BMI 35 and one BMI
19.  It may well be that the BMI 35 guy with a PSA of 3.3 is at
similar risk as is the BMI 19 guy with a PSA of 4.2

I wouldn't take my thinking on this subject to the bank,  but if we
accept the PSA dilution in one direction then it only stands to reason
that it operates in the opposite direction.

OK..  Just wanted to throw the 1,000,001-th bit of data calculation
into this PSA tea reading that everyone does.  Pray for a better
test.  Certainly we will be getting something in the next 5 to 10
years.