Does anyone know if orthostatic hypotension can affecttest blood creatinine level as a test of kidney function?

[Alan-pots-IST]

My creatinine levels keep changing and whenever I'm most symptomatic my levels are low but for a while when I was running around jogging and I wasn't as symptomatic my kidney was doing better so I'm trying to figure out does low blood pressure or I mean orthostatic hypotension affect the test, 

[firewatcher]

Serum Creatinine is used as a "marker" of kidney function because it remains relatively constant and is a reflection of muscle mass. HOWEVER it can be effected by diet (meat intake) and dehydration or hypovolemia (BUN is usually a better indicator of dehydration, but it is highly dependent on diet.) I am on a low protein, no red-meat diet to control my SCr and preserve my kidney function. ALSO, your kidney function can change based on position: a very few people have "free floating" or dropping kidney when they stand and that effects that kidney's ability to function and creates orthostatic HYPERtension. What my nephrologist has told me is that the numbers matter less than the trend over time: If there is a consistent and steady increase in SCr it is likely CKD, if there is a sudden massive increase in SCr that could be an acute crisis. Many dialysis patients have both hypotension and hypovolemia but I don't know if there are any studies or info on whether or how the BP and volume effect SCr. 

[Alan-pots-IST]

thank you for the information,

When you say BUN  is that UREA NITROGEN (BUN)? those numbers for the BUN seem to be good 18    7-25 Mg/dL   and everything else no protein in the urine it's just the CREATININE numbers fluctuate  eGFR NON-AFR. AMERICAN  78   and then 87  and now 70   .

 I have  orthostatic hypotension don't know why my blood pressure drops by 20 when I stand and I get a fast heart rate when I stand.

I think it's autoimmune.     whatever I'm symptomatic and my blood pressure drops more my kidney filtration rate  is worse.

This is been going on for 6 years now

[firewatcher]

Yes, Blood Urea Nitrogen is the BUN number. All of your Basic Metabolic Panel numbers can be looked at together to form a clearer picture of hydration status, which may cause the eGFR to change. At eGFR of 70-87, you would be very unlikely to be referred to a nephrologist; usually eGFR needs to drop below 60 for a primary care/internal medicine doctor to even consider it. YOU, however, do need to keep track of it, some docs won't tell you or refer until you reach the stage to need dialysis (eGFR <30). I have an Excel spreadsheet of all my labs from all my different doctors, and can see the trend over the years. 

[Lily]

I recently had some bad kidney numbers (creatinine and eGFR), but I retested after a week of aggressive rehydrating and the numbers went back to normal.

[Andy T]

Hi guys, im new here but had POTS since 2012. My UREA CREATININE & GFR fluctuate wildly each week and even in the same day. Currently my GFR is dropping from around 76 (I only have 1 kidney), down to high 20’s within 5 days. I stand up, function (actually the renal blood flow) drops.

if I lie down long enough it recovers slightly but normally I need IV fluids.

im normally hypovolemic & the pooling blood allows extracellular fluids to leak out rapidly. Anybody else got similar?

 

 

[firewatcher]

23 minutes ago, Andy T said:

Hi guys, im new here but had POTS since 2012. My UREA CREATININE & GFR fluctuate wildly each week and even in the same day. Currently my GFR is dropping from around 76 (I only have 1 kidney), down to high 20’s within 5 days. I stand up, function (actually the renal blood flow) drops.

if I lie down long enough it recovers slightly but normally I need IV fluids.

im normally hypovolemic & the pooling blood allows extracellular fluids to leak out rapidly. Anybody else got similar?

 

 

Have you been checked to see if that remaining kidney is dropping when you stand? https://www.medicalnewstoday.com/articles/319473.php Or something like "Nutcracker Syndrome?" Hopefully, you are being treated by a nephrologist!

[Andy T]

Hi & thanks for the reply.

when this was first discovered the medical team got very excited over the possibility of nutcracker syndrome. Apparently the kidney did move slightly but didn’t compromise the renal blood flow. The initial discovery began with 2 hourly blood tests (while in bed) followed by another test after 2 hours walking. (I was in hospital for 5 months at the time).

after the walk, creatinine had increased 70%. I’ve had renograms of renal artery & nothing is abnormal. Eventually this led to testing for Autonomic dysfunction. I have problems with hypotension & get sudden drops of 60 points on systolic pressure. My kidney function declines continually, providing I’m not lying down.

[firewatcher]

2 minutes ago, Andy T said:

Hi & thanks for the reply.

when this was first discovered the medical team got very excited over the possibility of nutcracker syndrome. Apparently the kidney did move slightly but didn’t compromise the renal blood flow. The initial discovery began with 2 hourly blood tests (while in bed) followed by another test after 2 hours walking. (I was in hospital for 5 months at the time).

after the walk, creatinine had increased 70%. I’ve had renograms of renal artery & nothing is abnormal. Eventually this led to testing for Autonomic dysfunction. I have problems with hypotension & get sudden drops of 60 points on systolic pressure. My kidney function declines continually, providing I’m not lying down.

WOW! That stinks! I think I have "plain old vanilla" chronic kidney disease as well as POTS. If you get referred to a POTS-aware kidney specialist, please let us all know who it is. 

 

[Andy T]

Yeah will do. Once I’ve had fluids and lay down enough I get all my kidney function back. I’m amazed how robust my kidney is, must have had over 50 episodes of acute kidney failure. I’m interested to hear if anyone else gets the leaking blood vessels & oedema!