Chronic kidney disease (CKD) is a common condition that affects millions of people worldwide, particularly older adults. It is characterized by a gradual loss of kidney function over time, leading to a buildup of waste products in the blood and potentially serious complications if left untreated. One of the challenges in diagnosing CKD in older adults is the role of cystatin C, a protein that is often used as a marker of kidney function.
Cystatin C is a small protein produced by all nucleated cells in the body, including the kidneys. It is freely filtered by the glomeruli, the tiny blood vessels in the kidneys that are responsible for filtering waste products from the blood. In healthy individuals, cystatin C is reabsorbed and broken down by the renal tubules, so only a small amount is excreted in the urine. However, in people with impaired kidney function, cystatin C levels in the blood can rise because the kidneys are not able to filter and clear it as efficiently.
Because cystatin C is not affected by muscle mass or diet, it is often considered a more reliable marker of kidney function than creatinine, another commonly used marker. Creatinine levels can be influenced by factors such as age, sex, and muscle mass, making it less accurate in older adults who may have lower muscle mass or other health conditions that affect creatinine levels.
However, recent research has shown that cystatin C levels can be influenced by factors other than kidney function, leading to potential misdiagnosis of CKD in older adults. For example, inflammation, infection, and certain medications can all affect cystatin C levels, leading to false positives or negatives in CKD diagnosis. In addition, cystatin C levels can vary between individuals based on genetic factors and other health conditions, further complicating its use as a marker of kidney function.
A recent review published in Nature Reviews Nephrology highlighted the potential pitfalls of relying solely on cystatin C for CKD diagnosis in older adults. The authors emphasized the importance of considering other factors, such as patient history, physical exam findings, and additional laboratory tests, when evaluating kidney function in this population. They also recommended using a combination of markers, including cystatin C and creatinine, to improve the accuracy of CKD diagnosis in older adults.
In conclusion, while cystatin C can be a valuable tool in assessing kidney function, its limitations must be taken into account when diagnosing CKD in older adults. Healthcare providers should be aware of the potential for misdiagnosis and consider a comprehensive approach to evaluating kidney function in this population. By incorporating multiple markers and clinical information, healthcare providers can ensure accurate diagnosis and appropriate management of CKD in older adults.
- The Renal Warrior Project. Join Now
- Source: Plato Data Intelligence.
- Source: https://renal.platohealth.ai/cystatin-c-and-the-misdiagnosis-of-ckd-in-older-adults-nature-reviews-nephrology/