Volume Overload and Creatinine Concentration

Mechanism and Clinical Significance

Volume overload can cause a decrease in serum creatinine concentration due to dilution effects, which may mask underlying kidney dysfunction, as noted by the European Society of Cardiology 1
In heart failure patients, fluid retention and volume overload can cause significant hemodilution of serum markers, according to the American Heart Association 2
Dilution from volume overload may mask deteriorating kidney function by artificially lowering serum creatinine values, as stated by the European Society of Cardiology and other guidelines 1, 3
In cirrhosis patients with ascites and volume overload, serum creatinine may appear normal despite significant reductions in glomerular filtration rate (GFR), as reported by the American Association for the Study of Liver Diseases 4, 5

In acute decompensated heart failure, fluid overload can dilute serum creatinine, making it appear falsely improved, as noted by the American College of Cardiology 2
Patients with cirrhosis often have splanchnic vasodilation leading to effective arterial blood volume reduction and fluid retention, which can dilute serum creatinine, potentially delaying diagnosis of acute kidney injury, as stated by the American Association for the Study of Liver Diseases 4

When assessing kidney function in patients with suspected volume overload, clinicians should consider the dilutional effect on creatinine, as recommended by the European Society of Cardiology and the American Heart Association 1, 2
In patients receiving ACE inhibitors who develop volume depletion, serum creatinine may rise due to both hemodynamic effects and concentration effects as volume normalizes, as reported by the American College of Cardiology 6, 7