MESO-Rx Exclusive Peter Bond on measuring kidney function in anabolic steroid users

[Millard]

In the latest MESO-Rx original article, @PeterBond discusses the problem with the use of traditional kidney function tests in anabolic steroid users and more useful alternative tests.

"Estimating the GFR based on the serum creatinine concentration is notoriously unreliable in muscular individuals. Since muscle is the primary storage site of creatine in the body, muscular individuals will carry around more creatine in their bodies. Consequently, the rate of creatinine production is also higher. As such, with similar clearance rates, the serum creatinine levels will also be higher. As a result, these formulas will underestimate the true GFR. Another issue that arises in this population is one caused by creatine supplementation."

Measuring Kidney Function in Anabolic Steroid Users

The kidneys are responsible, among other things, for filtering the blood and producing urine. They do so by creating a filtrate from the large amounts of

thinksteroids.com

 

[juicebro]

So training, mass, AAS etc increase creatinine levels. A high creatinine or low GRF does not mean you have kidney problems. What if your creatinine and creatinine based GRF is in range while you are on AAS? Is there any reason to dive deeper into it and run other tests to see if your have any issues with your kidneys? I've only tested my creatinine and urea every time. They've been always within the range whatever I'm on so I've assumed my kidneys are fine.

 

[PeterBond]

So training, mass, AAS etc increase creatinine levels. A high creatinine or low GRF does not mean you have kidney problems. What if your creatinine and creatinine based GRF is in range while you are on AAS? Is there any reason to dive deeper into it and run other tests to see if your have any issues with your kidneys? I've only tested my creatinine and urea every time. They've been always within the range whatever I'm on so I've assumed my kidneys are fine.

A high creatinine (and consequently low eGFR) can indicate a decrease in kidney function, but chances are a lot higher that it's due to those causes you're mentioning. A progressive increase in creatinine, or strongly elevated levels, should prompt further evaluation, regardless.

If creatinine and eGFR are normal, one could still take an annual or biannual urine analysis to check for proteinuria. Although in general AAS per se appear unlikely to be detrimental to the kidneys.

As such, it might be recommended to do urine measurements somewhat regularly. For example, annually or biannually. Slight elevations of albumin in the urine should prompt for a retest, as this can also result from for example infection or exercise, without being caused by actual kidney damage. With persistent elevations or large elevations further follow up should be initiated and, ideally, anabolic steroid usage should be stopped.

 

[malfeasance]

My surface area right now is over 2.3 meters squared, on any of the five methods of calculation, and BMI is 32.5, so I am thinking that the eGFR is not only low for me, but probably useless. To get down to 1.73, I would need to weigh 123 pounds (six feet tall). There is something drastically wrong here, if 1.73 is the body surface area used for the calculation.

 

[PeterBond]

My surface area right now is over 2.3 meters squared, on any of the five methods of calculation, and BMI is 32.5, so I am thinking that the eGFR is not only low for me, but probably useless. To get down to 1.73, I would need to weigh 123 pounds (six feet tall). There is something drastically wrong here, if 1.73 is the body surface area used for the calculation.

The GFR is expressed as mL/min/1.73 m2 body surface area. It does not assume that that's your body surface area.

It would be rather tedious to express the eGFR based on somebodies estimated body surface area (BSA) with each measurement. It would make comparison over time difficult in an individual with changes in BSA, and it also makes it difficult to compare it to others (and thus to reference ranges etc.)

As such, the eGFR is always normalized to a BSA of 1.73m2, which is roughly the average of a human being. This makes comparisons over time possible as well as between individuals. This, of course, does not imply that the calculation assumes that that's your BSA. The result is simply normalized to this unit for comparison's sake.

 

[malfeasance]

Ah, so I completely missed the import of this number.

 

[PeterBond]

It's very likely underestimating your GFR anyhow given that BMI and assuming it's mostly due to muscle mass.

 

[Type-IIx]

Peter Bond:

The reaction catalyzed by AGAT, forming guanidinoacetic acid, is the rate-limiting step in the synthesis of creatine [9]. It has been found that administration of an anabolic steroid (17α-methyl testosterone) increases AGAT expression [10]. Moreover, it increased the excretion of guanidinoacetic acid in the urine by 70 %. Taken together this is strongly suggestive of, at least oral bioavailable, anabolic steroids stimulating the biosynthesis of creatine.

Wooo, is there anything AAS don't do to slab on muscle?

Finally, most anabolic steroid users are also consuming a high-protein diet. A high-protein diet has been found to increase the GFR [11]. Note that this is not an overestimation of the GFR, it actually increases the true GFR a bit.

Don't worry, I won't translate this and cause a 15 page flame war.

@PeterBond since trenbolone has been the topic du jour lately: I know research on this compound is scant except in cattle, but do you have any cautiously hypothetical ideas for why users report darkened urine from use (is it indicative of proteinuria)? Slightly tangentially, do you know if/why trenbolone is perceived as detrimental to aerobic fitness?

 

[malfeasance]

It's very likely underestimating your GFR anyhow given that BMI and assuming it's mostly due to muscle mass.

It's all muscle mass. I have like 0% body fat! No, make that negative 2% body fat! I'm not fat! I'm bulking! I can see abs when flexing if the light is right, maybe holding water.

 

[Tmisatix]

A high creatinine (and consequently low eGFR) can indicate a decrease in kidney function, but chances are a lot higher that it's due to those causes you're mentioning. A progressive increase in creatinine, or strongly elevated levels, should prompt further evaluation, regardless.

If creatinine and eGFR are normal, one could still take an annual or biannual urine analysis to check for proteinuria. Although in general AAS per se appear unlikely to be detrimental to the kidneys.

What are your thoughts on high dose astralagus? People are posting blood results when doing it and seems to result in higher gfr numbers.

 

[PeterBond]

Peter Bond:

Wooo, is there anything AAS don't do to slab on muscle?

Don't worry, I won't translate this and cause a 15 page flame war.

@PeterBond since trenbolone has been the topic du jour lately: I know research on this compound is scant except in cattle, but do you have any cautiously hypothetical ideas for why users report darkened urine from use (is it indicative of proteinuria)? Slightly tangentially, do you know if/why trenbolone is perceived as detrimental to aerobic fitness?

Proteinuria itself doesn't cause a discoloration of urine, but leakage of red blood cells in the urine can. But I don't think that's the cause (if only because the color probably doesn't match, as some would get pink-looking urine, too, and it's an otherwise more pronounced red color).

Few other things that can cause such discoloration are something aching to rhabdomyolysis (perhaps tren users go all out in the gym), dehydration (maybe they sweat more and 'forget' to appropriately rehydrate), and perhaps a metabolite causes it, as some medications are known to lead to urine discoloration too. There are some other kidney and liver disorders which can cause it, but it would surface in other ways too. But importantly, I have no idea, as there's no research on this I think.

I could also speculate about why it's perceived as being detrimental to aerobic fitness, but I haven't really given that a good look yet.

 

[PeterBond]

What are your thoughts on high dose astralagus? People are posting blood results when doing it and seems to result in higher gfr numbers.

Unless you have actual kidney dysfunction I do not see the use of specifically targeting the kidney anyhow. Astragalus has some scarce evidence in diabetic nephropathy, that's a far-stretch to hypothetical AAS-induced reductions in GFR. The number might go up, but that doesn't necessarily mean it's something good either. A high-protein diet leads to hyperfiltration as well without having a beneficial effect on kidney disease progression.

 

[Type-IIx]

Proteinuria itself doesn't cause a discoloration of urine, but leakage of red blood cells in the urine can. But I don't think that's the cause (if only because the color probably doesn't match, as some would get pink-looking urine, too, and it's an otherwise more pronounced red color).

Few other things that can cause such discoloration are something aching to rhabdomyolysis (perhaps tren users go all out in the gym), dehydration (maybe they sweat more and 'forget' to appropriately rehydrate), and perhaps a metabolite causes it, as some medications are known to lead to urine discoloration too. There are some other kidney and liver disorders which can cause it, but it would surface in other ways too. But importantly, I have no idea, as there's no research on this I think.

I could also speculate about why it's perceived as being detrimental to aerobic fitness, but I haven't really given that a good look yet.

As always, thank you again!