[Evaluating Kidney Function in older Adults - how to ensure accurate Assessment].

A decline in glomerular filtration rate (GFR) is considered a physiological change in older age. Accurate estimation of the eGFR is essential not only for establishing a diagnosis but also for selecting appropriate medications and determining correct dosages, in order to avoid both under- and overdosing, as well as associated adverse drug reactions. In patients with signs of sarcopenia, relying solely on serum creatinine or creatinine-based eGFR may lead to an overestimation of kidney function. In older adults, the most accurate estimation of eGFR is achieved by using equations that combine creatinine and cystatin C. The currently recommended EKFC equation has been well validated in a large cohort of older European individuals. In cases of suspected kidney disease, a spot urine test for albumin and creatinine - with calculation of the albumin-to-creatinine ratio (UACR) - should also be performed in older adults.