Medications Influencing Serum Cystatin C Independent of Measured Glomerular Filtration Rate

The authors aimed to determine whether certain medications influence serum cystatin C levels independently of measured glomerular filtration rate (mGFR) and to assess the impact of these medications on cystatin C-based estimated GFR (eGFRcys) compared to creatinine-based estimates. They found that systemic glucocorticoids, opioids, and loop diuretics were associated with increased cystatin C levels, particularly glucocorticoids at higher doses, while other medications showed no significant effects. Additionally, eGFRcys underestimated mGFR more in users of these medications, whereas the combined eGFRcr-cys provided the most accurate GFR estimates.