63 replies to this topic

[albedo]

Not sure this is available also on LE in US: https://www.lifeexte...com/kidney-care. No experience with this supplement supposed to help for kidney health but thought to log it here too.

https://www.lifeexte...com/kidney-care

[albedo]

How do I know if my GFR testing was for cystatin c?  It just says GFR.  Also, you mention "based on age and body weight".  Is that something I can apply manually in some kind of an equation to my GFR value?

 

If you did not test for cystatin-c typically the give eGFR based on creatinine only. If you have a cystati-c value you can yourself enter it into a formula to get eGFR. You have all formulas here (note also the update in 2021):

https://www.kidney.o.../gfr_calculator
 

[Rocket]

If you did not test for cystatin-c typically the give eGFR based on creatinine only. If you have a cystati-c value you can yourself enter it into a formula to get eGFR. You have all formulas here (note also the update in 2021):
https://www.kidney.o.../gfr_calculator

My doc thought i was in kidney failure until i to the cystatin c test.

Egfr is exactly that.... estimated and it's estimated relative to low muscle mass low weight people who don't exercise or eat a lot of protein

People with muscle mass and who exercise is common to have "abnormal" egfr tests.

Edited by Rocket, 04 November 2022 - 01:01 AM.

[albedo]

My doc thought i was in kidney failure until i to the cystatin c test.

Egfr is exactly that.... estimated and it's estimated relative to low muscle mass low weight people who don't exercise or eat a lot of protein

People with muscle mass and who exercise is common to have "abnormal" egfr tests.

 

agree! very good you did a cystatin-c baseline, it is not normally ordered and much more indicative. See also:

https://www.lifeexte.../kidney-health#

 

 

Cystatin C. Cystatin C is a newer blood marker of kidney function and has numerous advantages over standard tests. Unfortunately, it is not currently part of the standard blood chemistry panel, but it is available upon request from several labs. While mainstream medicine is just beginning to incorporate cystatin C testing into the clinic, Life Extension reported on the value of this novel blood test back in 2006 (Wagner 2006), and customers can purchase a cystatin C blood test through the Life Extension website.

Compared with creatinine, cystatin C is less influenced by age, gender, body composition, diet, or preexisting infection or cancer, so its blood levels are more consistent across different patient populations (Lassus 2012; Shlipak, Matsushita 2013). This may make it a more sensitive indicator of GFR, and thus of kidney disease (Newman 1995; Mussap 2002). Indeed, a large analysis of pooled data from 11 general population studies involving 90 750 subjects and five additional studies of CKD patients involving 2960 subjects found that cystatin C is a better predictor of declining kidney function than creatinine. Whereas creatinine-based estimates of GFR are able to predict risks associated with declining kidney function when eGFR levels fall to 60 mL/min/1.73m2 or less, GFR estimates based on cystatin C level are predictive at approximately 85 mL/min/1.73m2. In other words, cystatin C-based estimates of GFR are able to predict risk when the magnitude of the decline in kidney function is less pronounced than that necessary for creatinine-based GFR estimates to be predictive. Although chronic kidney disease is not diagnosed until the eGFR reaches 60 mL/min, being able to detect earlier, less-significant decrements in kidney function is important, as the period of subclinical kidney dysfunction before overt kidney disease can be diagnosed based on creatinine may last one to two decades (Rush-Monroe 2013; Shlipak, Matsushita 2013).

Another advantage of cystatin C over creatinine is that while creatinine production is highly variable across populations, cystatin C production is more uniform. Since creatinine is a byproduct of muscle metabolism, individuals with greater muscle mass, those who engage in more physical activity, or those generally in better health produce more creatinine than people with lower muscle mass, physical activity levels, and poorer overall health. Thus, determining GFR based on creatinine levels requires that doctors approximate the rate of creatinine generation, which may not take all variables into account (Shlipak, Mattes 2013).

Current recommendations suggest that cystatin C measurement be used in combination with creatinine testing to confirm kidney disease diagnosis in patients with reduced GFR (45–59 mL/min) but no other signs of kidney damage (Shlipak, Mattes 2013).

Cystatin C is a better indicator of kidney function in elderly patients and predicts outcomes more accurately than creatinine (Hojs 2004; Fliser 2001). Compared with GFR, cystatin C has a stronger association with death from cardiovascular or any other cause in those with advanced CKD (Menon 2007; Ferri 2014c).

Cystatin C appears to offer novel applications beyond kidney function. In patients with normal kidney function, it was strongly and significantly associated with the risk of venous thromboembolism (Brodin 2012). Moreover, cystatin C has recently emerged as a promising predictor of cardiovascular risk (Salgado 2013; Angelidis 2013; Lassus 2012). Although more research is needed before cystatin C can be widely used to assess cardiovascular risk, studies so far suggest cystatin C testing may be a reliable measure of risk of incident or recurrent cardiovascular events and adverse outcomes. Also, cystatin C has been shown to be predictive of heart failure development, and increased levels have been associated with increased mortality in both acute and chronic heart failure (Lassus 2012).

Importantly, there are some populations in whom cystatin C may not provide accurate measurements of kidney function. These include people with uncontrolled thyroid disease and those using corticosteroids. These individuals should discuss the best kidney function testing options with their healthcare provider (Shlipak, Mattes 2013).