Table 2.

Some factors that may influence serum creatinine and cystatin C measurements

FactorsSerum CreatinineSerum Cystatin C
Filtration marker generationBody massIncreased by corticosteroids
Race/ethnicityIncreased in hyperthyroidism
DietDecreased in hypothyroidism
Nutritional status
Catabolic states
Ingestion of cooked meats
Rhabdomyolysis
Nonrenal eliminationClearance by RRT
Decreased by inhibition of gut creatininases by antibiotics
Increased by insensible losses
Inhibition of tubular secretionCimetidine, ranitidineNone
Fenofibrate
Trimethoprim
Albumin
Dolutegravir
Cisplatin
Flucytosine
Assay interferenceDrugs (flucytosine, barbiturates, some cephalosporins, N-acetylcysteine, some catecholamines [such as dopamine], dobutamine)
Others (bilirubin, ketones, glucose)