The serum creatinine may be low for a number of reasons, some of which may be significant for the patient.




protein malnutrition

low skeletal muscle mass

increased mortality in the ICU

advanced age

low skeletal muscle mass

muscle weakness


physiologic hemodilution

a creatinine in the normal range may be abnormal

artifactual dilution

collection from a line infusing fluids

other analytes also low

pathologic hemodilution

fluid overload


renal loss in diabetes or other nephropathies

glomerular hyperfiltration or tubular secretion




• A low serum creatinine is a better indicator for malnutrition than body weight. Fat or fluid retention can result in a normal body weight despite low muscle mass.

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