Can drinking water before bloodwork cause lower gfr result?

[Dllfb]

Everything I read says to make sure to be hydrated for bloodwork. I have category 3a kd and drink 10 cups of water daily. I usually go for bloodwork when I get up in the morning without drinking anything and b4 breakfast. Last couple of times I went, my gfr had dropped and was told it was likely because I was dehydrated...to drink more in the next few days and go for another bloodwork. I drank two or three more cups of water daily and before going for the bloodwork on those mornings I had a cup of water too. Both times my results showed a gfr 6 and 7 points lower than the previous weeks test. I’m scheduled for bloodwork next week and don’t know if I should drink anything before the test that morning.mmHas anyone else experienced this?

[Hidden]

You might want to look at everything you are doing in the two or three days before the labs are drawn. Being well hydrated is the best way to get natural results. You really need consistency in your eating and drinking to get accurate readings and slow the progression. I don't change my meals or drinking. If the weather is nice and I want to go for a longer bike ride then I do it after my labs and not within a few days of my next one.

I've included an article below that will answer a lot of questions about dehydration. For other definitive answers regarding your specific health issues you need to speak to your nephrologist and your renal dietitian.

If you want consistency and accuracy in your readings everything you do must have the consistency you seek in the lab work. Having CKD and being successful in slowing the progression is all about lifestyle changes and once you make the required changes for you, you must be consistent.

Finally, not all blood tests require you to fast. Check with your ordering physician and find out when they order the labs if they want you to fast. If they do, they schedule the tests in the morning. If not, then go later in the day. If you are consistent, it will not make a difference.

myonemedicalsource.com/2020...

[madonbrew]

Personally, I don’t worry too much because one way or another it’s a manipulation of the result. The others might disagree but I think just do what’s normal for you and over time the trend will show what’s happening.

[RhenDutchess123 in reply to madonbrew]

Right....when you try to manipulate the Lab Results you are just wasting your own time and money and are not getting accurate results of the body you live in everyday

[madonbrew in reply to RhenDutchess123]

Indeed 😊

[Dllfb in reply to RhenDutchess123]

I’m not trying to manipulate my results...just wanting to know which way is more accurate. When I’m told by my dr that my gfr result was low because I was likely dehydrated and to drink more and redo the test in a few days...and I did so and find that my results are 7 points lower... and this happened twice...well I figure next time I will hydrate like I usually do....and not drink before going for bloodwork too.

[RhenDutchess123 in reply to Dllfb]

You may be dehydrated and you may also be low in gfr...you could also be drinking to much water right before the test and causing your kidneys to work harder....lab work is just a snap shot in time....You should just do what you would normally do on a day tou dont get bloodwork...test what environment your body is usually In.

You also dont mention the number your GFR is reporting...different stages of ckd require different needs for water and diet requirement

[Dllfb in reply to RhenDutchess123]

I’m is stage 3A.

[Hidden in reply to Dllfb]

You are not manipulating your results by being consistent with your meals and fluids.My point was being consistent every day with your meal plan and staying hydrated is what your new normal lifestyle should be.

Don't change your plan and stop drinking before labs or eat anything, not on your plan.

Also, keep to your normal exercise regimen. If you want to do something "extra" do it after labs are done and not before.

If you change your routine that is manipulating the results.

Finally, drinking water helps by removing toxins that build up because your kidneys aren't able to do their job as they once did. Anything else is irresponsible.

[Glyndwright in reply to Dllfb]

Hi I had kidney failure in October 2028. Was on dialysis for around 3 months, kidneys improved to around 45%. No.longer on dialysis. Was always told to limit my fluid intake to 1 litre a day. Its only in the last few months my kidney function has gone down to 24% at my last blood test. Forgot to say I M a young 71 male.

[JayVeeJayVee]

I think one of the reasons for drinking is because it is easier to find a decent vein. Drinking water helps a lot. You may well get a bit dehydrated overnight.Hope that helps.