Collaborative Study Reveals Cystatin C is a More Accurate Indicator of Renal Function Than Creatinine
In a collaborative study between pharmacy and nephrology faculty at the University of California, Irvine and the Department of Medicines from the University of Mississippi Medical Center and Houston Methodist, a group of researchers found that analyzing the protein cystatin C is a more accurate indicator of renal function than creatinine.
Knowing an accurate and appropriate estimation of how well the kidneys are working, also known as renal function, helps physicians and pharmacists minimize under or overdosing medication therapies to improve effectiveness and reduce toxicities.
Healthcare professionals often use creatinine, a waste product made by muscles that can be measured in the blood, to predict kidney function. However, creatinine levels can be influenced by a multitude of factors, such as age, diet, or other medical conditions that affect muscle mass.
In the review published in Current Opinion in Nephrology and Hypertension, the researchers advocate for using cystatin C to more accurately estimate renal function.
“A more modern approach to determining renal function is important because healthcare professionals can provide a more accurate medication dosing regimen,” says Lee Nguyen, PharmD, co-corresponding author and Health Sciences Associate Clinical Professor at the UCI School of Pharmacy & Pharmaceutical Sciences. “Patients with poor renal function may require a dose reduction to minimize medication-related toxicity. Similarly, a patient with increased renal function may need more medication for the dosage to be effective.”
The use of cystatin C does not have the same limitations as creatinine with regard to age, diet, or low muscle mass that can skew the estimation of renal function.
“Cystatin C can be used to more accurately estimate renal function, which not only equips pharmacists with more information on what doses should be given but can also be used to help identify medication-related renal toxicity more quickly,” says Dr. Nguyen.
The co-authors include Alexandre Chan, PharmD, Professor of Clinical Pharmacy and Founding Chair, Department of Clinical Pharmacy Practice, UCI School of Pharmacy and Pharmaceutical Sciences, Kamyar Kalantar-Zadeh, MD, Professor of Medicine, UCI School of Medicine, and faculty from the Department of Medicines from University of Mississippi Medical Center and Houston Methodist.