Urine Protein to Creatinine Ratio

Kidney Function marker

Protein/Creatinine Ratio

Urine Protein to Creatinine Ratio

Category: Kidney Function
Unit: mg/mmol

Ratio of total urine protein to creatinine in a single spot sample, used to estimate daily protein loss without a 24-hour collection. Unlike the albumin/creatinine ratio it counts every protein in the urine, not just albumin. KDIGO categories: under 15 mg/mmol is normal to mildly increased, 15-49 is moderately increased, and 50 or above is severely increased.

PED Notes

The kidney marker most likely to be misread in a bodybuilder, in both directions. Heavy training causes transient proteinuria that clears within a day or two, so a raised result straight after a hard session can be a false alarm; retest on a rest day using first morning urine. The opposite error matters more. The ratio divides protein by urine creatinine, and a large muscle mass excretes more creatinine, which pulls the ratio down and can understate real protein loss. The same muscle mass raises serum creatinine, so genuine kidney damage is easy to dismiss as 'just muscle'. Long-term anabolic steroid use has been linked to focal segmental glomerulosclerosis (FSGS) presenting as heavy proteinuria in bodybuilders; in that series all seven patients who stopped steroids saw proteinuria fall, and the one who resumed relapsed (Herlitz et al., 2010). A persistently raised PCR on cycle warrants stopping, confirming with ACR and cystatin C based eGFR, and medical review.

When high

PCR Categories (KDIGO 2024):

  • Normal to mildly increased (A1): under 15 mg/mmol
  • Moderately increased (A2): 15-49 mg/mmol
  • Severely increased (A3): 50 mg/mmol or above

If Elevated (15 mg/mmol or above):

  • Repeat on first morning urine, on a rest day, at least 48 hours after heavy training
  • Rule out: urinary tract infection, fever, dehydration, menstruation, recent intense exercise
  • Confirm persistence with repeat samples over 3 months before treating it as kidney damage
  • Run the albumin/creatinine ratio (ACR) alongside it. ACR is more sensitive at low levels, and a PCR well above what the ACR predicts points to non-albumin (tubular or overflow) proteinuria
  • Check eGFR, ideally cystatin C based in muscular users, plus blood pressure and urine microscopy for blood

Supplements:

  • Omega-3 Fish Oil -- 2-4g/day; modest evidence for reducing proteinuria, supportive only and not a substitute for treatment

Pharmacological options (for confirmed persistent elevation):

  • Telmisartan / Losartan -- ARB; reduces proteinuria and slows progression; first-line when PCR stays raised, especially with high blood pressure
  • Ramipril / Lisinopril -- ACE inhibitor; equivalent antiproteinuric effect; monitor for cough and hyperkalaemia
  • Empagliflozin / Dapagliflozin -- SGLT2 inhibitor; recommended by KDIGO 2024 for chronic kidney disease with significant proteinuria, whether or not diabetes is present
  • Do not combine an ACE inhibitor with an ARB (additive hyperkalaemia and acute kidney injury risk)
  • All require physician oversight, with potassium and eGFR checked before and after starting

PED-specific:

  • Stop anabolic steroids if proteinuria persists. In the Herlitz case series all seven patients who stopped saw proteinuria fall, and the one who resumed relapsed
  • If a full stop is not happening, drop trenbolone and oral compounds first
  • Stop chronic NSAID use and switch to paracetamol
  • Control blood pressure to under 130/80
  • Refer to nephrology at 50 mg/mmol or above, or with any sustained rise alongside falling eGFR

Educational information, not medical advice. Nothing here is a prescription or a treatment plan, and it does not account for your history, medications or conditions. Use it to ask better questions: bring it to your doctor and decide together. Full disclaimer.

History Chart

Reading History

Frequently Asked Questions

Reference Ranges

Standard Range

Not available

Statistics