Re: Rephrasing the question...

[Guest guest]

Hi Mike:

In the article that cited in one of his recent posts I found this

reference to calculating PRA ratio.

" Plasma aldosterone - PRA ratio

When aldosterone is measured in ng/dL and PRA is measured in ng/mL/h, a ratio

greater than 20-25 has a 95% sensitivity and a 75% specificity for PH. When

aldosterone is measured in pmol/L, a ratio greater than 900 is consistent with

PH. "

I used this same method to calculate my ratio in Feb., my ratio was 146.5. I

confirmed this with the lab that did the work. There are only 4 labs in the

country (anyway that's my understanding) that do this lab work. I was able to

find their procedure and method of calculating the ratio on the interent and

compare it with my lab report. It verified that my first calculation was

correct. Then my Dr. confirmed again that it was correct. I am under the

impression that different labs use different measurements and it is important to

verify with the lab their method of calculation. My lab also had measurements

for upright and suspine.

Good luck,

May we all be DASHing...

Randy

[Guest guest]

When PRA is measured after sodium depletion with the Grim-Weinberger Protocol and the aldo after saline the Sens and Spec is much higher but more trouble.

see

Weinberger MH, Grim CE, Holifield JW, Kem DC, Ganguly A, Kramer NJ, Yune HY, Wellman H, and Donohue JP. Primary aldosteronism: diagnosis, localization and treatment. Ann Int Med 1979;90: 386-395

May your pressure be low!

Clarence E. Grim, BS (Chemistry and Mathematics), MS (Biochemistry), MD

Professor of Medicine and Epidemiology

Medical College of Wisconsin

Board certified in Hypertension, Internal Medicine and Geriatrics

[Guest guest]

--- In hyperaldosteronism , " sheltonlayne@n... "

> I used this same method to calculate my ratio in Feb., my ratio was

146.5. I confirmed this with the lab that did the work. There are

only 4 labs in the country (anyway that's my understanding) that do

this lab work. I was able to find their procedure and method of

calculating the ratio on the interent and compare it with my lab

report. It verified that my first calculation was correct. Then my

Dr. confirmed again that it was correct. I am under the impression

that different labs use different measurements and it is important to

verify with the lab their method of calculation. My lab also had

measurements for upright and suspine.

Randy,

Well, the Direct renin assay is a little different from the PRA, but I

found a cnversion, and it looks like my PRA would be about 1.25.

16/1.25... so that is still under the 25-25 number for a positive.

I know that with cushings disease (our sister disease), there are

times when they get a normal reading (they call it a " low " period),

interspursed with " bursts " of cortisol (their " high " period). I'd

imagine that it would be the same for us, but most of the texts do not

seem to recognize that phenomenon.

Thanks,

Mike

[Guest guest]

If the supine is abnormal then it is OK. But is may not be abnormal.

Would not vary much from day to day.

The steroid would not likely affect it unless you have GRA and it might

as steroids in GRA will drive the aldo to zero. Don't know how long a

suppository would last. It would mostly affect the aldo not the PRA.

Do you have the exact number from your previous test?

lord_mike_the_great wrote on 8/16/04, 5:09 PM:

>

> Would a supine aldosterone/renin ratio be invalid or not useful? Is

> it possible to be significantly abnormal one day (with a ratio fo 48)

> and then a few weeks later be totally normal with a tumor, etc? Would

> it be possilbe that a steroid suppository taken 4 days before for my

> colitis have affected the testing?

>

> Thanks,

>

> Mike

>

>

> > Ok, my GP wanted to rerun the tests that my nephrologist did. So we

> > did some blood work, and the urine is still being processed. Anyways,

> > I get a call this morning, adn they said everything was normal! Huh??

> > So, I went and got the labs. Please note that the lab tech INSISTED

> > that I be lying down for 30 minutes before doing the test, which I

> > think may have screwed things up. I was syumptomatic and hypertensive

> > prior to the testing.

> >

> > Potassium: 3.9 mmol/L

> > Aldosterone: 16.7 ng/dL

> > Renin, Direct: 6.8 uU/ml

> >

> > I have no idea how to measure the aldosterone/renin ratio, 'cos the

> > units are different. What's uU/ml? It's supposed to be measured in

> > ng/mL/h. Help! Dr. Grim? Anyone? Last time it was 48, could it be

> > that the original testing was an error, and my hopes were raised for

> > absolutely nothing?

> >

> > Thanks,

> >

> > Mike

>

>

>

>

>

>

[Guest guest]

Dr. Grim,

All I know from the previous test was that my aldo/renin ratio was

48, and my 24-hour urinary aldosterone was elevated (by how much, I

don't know), and urinary sodium was 175. I will get the exact

details on Thursday.

Would the minimum ratio be higher for upright vs. supine? In other

words, fo the ratio cutoff was 1.5 for upright, would that number be

higher or lower for testing after 30 minutes supine?

Thanks,

Mike

> > > Ok, my GP wanted to rerun the tests that my nephrologist

did. So we

> > > did some blood work, and the urine is still being processed.

Anyways,

> > > I get a call this morning, adn they said everything was

normal! Huh??

> > > So, I went and got the labs. Please note that the lab tech

INSISTED

> > > that I be lying down for 30 minutes before doing the test,

which I

> > > think may have screwed things up. I was syumptomatic and

hypertensive

> > > prior to the testing.

> > >

> > > Potassium: 3.9 mmol/L

> > > Aldosterone: 16.7 ng/dL

> > > Renin, Direct: 6.8 uU/ml

> > >

> > > I have no idea how to measure the aldosterone/renin

ratio, 'cos the

> > > units are different. What's uU/ml? It's supposed to be

measured in

> > > ng/mL/h. Help! Dr. Grim? Anyone? Last time it was 48,

could it be

> > > that the original testing was an error, and my hopes were

raised for

> > > absolutely nothing?

> > >

> > > Thanks,

> > >

> > > Mike

> >

> >

> >

> >

> >

> >

[Guest guest]

Hard to say as not many have studied it carefully in both supine and upright in a lot of pts with PA.

The problem is that the lower limit of detectability for renin in the supine position usually overlaps in PA with what one seens in many normal and HTNs without PA.

In our own data the ratio will be lower in the upright postiion as renin tends to be higher and aldo may stay the same or go higher.

May your pressure be low!

Clarence E. Grim, BS (Chemistry and Mathematics), MS (Biochemistry), MD

Professor of Medicine and Epidemiology

Medical College of Wisconsin

Board certified in Hypertension, Internal Medicine and Geriatrics

[Guest guest]

Dr Grim:

In following the different techniques for identifying

hyperaldostronism, I note that most are not definitive. In fact,

when I was suspected I had three of them, 2 positive and 1 negative.

Only the vein sampling was considered definitive. This was after the

other three. Also no observable lump was found with a CAT. This and

the vein sampling where fairly expensive.

Why not put a patient with htn and hypokalimia on a 5 week course

of spiro, and check the progress of his blood pressure? This seems a

fast, inexpensive to determine the most probable cause nonessential

hypertension. Wayne

> Hard to say as not many have studied it carefully in both supine

and upright

> in a lot of pts with PA.

>

> The problem is that the lower limit of detectability for renin in

the supine

> position usually overlaps in PA with what one seens in many normal

and HTNs

> without PA.

> Professor of Medicine and Epidemiology

> Medical College of Wisconsin

> Board certified in Hypertension, Internal Medicine and Geriatrics

[Guest guest]

This is my approach. If BP and K can be controlled with meds I do not proceed with special studies-they are expensive and carry some risk. I only do them if I will operate if they are abnormal.

In medicine few tests or even sequence of tests are always 100%.

In a message dated 8/19/04 3:56:41 PM, wbongianni@... writes:

Dr Grim:

     In following the different techniques for identifying

hyperaldostronism, I note that most are not definitive.  In fact,

when I was suspected I had three of them, 2 positive and 1 negative. 

Only the vein sampling was considered definitive.  This was after the

other three.  Also no observable lump was found with a CAT. This and

the vein sampling where fairly expensive.

    Why not put a patient with htn and hypokalimia on a 5 week course

of spiro, and check the progress of his blood pressure?  This seems a

fast, inexpensive to determine the most probable cause nonessential

hypertension.  Wayne

> Hard to say as not many have studied it carefully in both supine

and upright

> in a lot of pts with PA.  

>

> The problem is that the lower limit of detectability for renin in

the supine

> position usually overlaps in PA with what one seens in many normal

and HTNs

> without PA.  

> Professor of Medicine and Epidemiology

> Medical College of Wisconsin

> Board certified in Hypertension, Internal Medicine and Geriatrics