Andrew S. Levey’s research while affiliated with Tufts Medical Center and other places

... We speculated that CK might be associated with sarcopenia or low MM. On the one hand, serum CK levels are positively correlated with a number of parameters that directly re ect muscle mass, including BMI, creatinine, and urinary creatinine (UCR) (UCR is a known marker of muscle mass) (30,31). A cross-sectional study of 1086 hospitalized T2DM patients revealed that CK was inversely correlated with low MM and was positively correlated with the skeletal muscle index (SMI) (10). ...

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Association between serum creatine kinase levels and the risk of all-cause mortality among centenarians: A prospective cohort study in China

... Previous studies have found that microbial effects on host phenotypes can be driven by changes in circulating metabolites, which then interact with host receptors or pathways 18,[49][50][51] . Studies focused on metabolites related to GFR in CKD patients found that some metabolites are positively but some are negatively associated with estimated GFR [52][53][54][55] . Of note, the secretion of microbial metabolites can be influenced by transporters such as organic anion transporter-1 (OAT-1) 56 . ...

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Microbes regulate glomerular filtration rate in health and chronic kidney disease in mice

... Highprotein diets, particularly those rich in meat, not only increase the risk of cardiovascular disease but also elevate CKD incidence and accelerate its progression as a result of increased intraglomerular pressure as well as glomerular hyperfiltration. Meat consumption raises the production of nitrogenous waste, exacerbates uremia, and may lead to constipation, resulting in hyperkalemia due to typically low fiber intake (50,51). Additionally, we should focus on the increasing burden of CKD caused by a diet high in red meat and a diet high in processed meat in countries and regions with high SDI levels. ...

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Global, regional, and National Burden of chronic kidney disease attributable to dietary risks from 1990 to 2021

... However, SCr levels are influenced by factors such as age, gender, height, muscle mass, and dietary composition [18], leading to potential inaccuracies in SCr-based eGFR (eGFRs) calculations and a possible overestimation of the true eGFR [19]. Studies have shown that eGFR based on CYST is more sensitive than eGFRs in predicting cardiovascular outcomes in mild CKD and early kidney injury after kidney transplantation [20,21]. CYST is continuously transcribed and expressed in nucleated cells without specific histologic features. ...

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The independent and interactive effects of heavy metal pollution and vitamin D deficiency on early kidney injury indicators: analysis of the National Health and Nutrition Examination Survey 2001–2004

... Accurate glomerular filtration rate (GFR) estimation is crucial for diagnosing kidney disease and prescribing renal risk medications [1][2][3]. In clinical practice, estimated GFR (eGFR) is typically determined by plasma creatinine levels adjusted for age and sex (eGFR cre ) [4]. However, creatinine is an imperfect metric of GFR, particularly in older (age ≥ 65 years) hospitalized patients, due to age-related changes in non-GFR factors such as muscle mass and nutritional status that affect creatinine level [5]. ...

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Plasma NGAL, suPAR, KIM‐1 and GDF‐15 for Improving Glomerular Filtration Rate Estimation in Older Hospitalized Patients

... In general, we urge that caution be used in adopting disease-specific eGFRcr equations, or using disease status as a variable in eGFR equations for the general population. 8 Wider use of cystatin C with creatinine measures substantially improves the accuracy of GFR estimation in other settings, and future studies should evaluate eGFRcr-cystatin C equations in KTRs. In addition, wider implementation of mGFR procedures in transplant centers should be encouraged. ...

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Estimating GFR in Kidney Transplant Recipients: Considerations for Selecting Equations

... We could not address the question of accuracy without measured GFR. However, in the Swedish cohort study where concurrent plasma clearance of iohexol, SCR, and CysC were measured, eGFR SCR-CysC equations performed best with minimal variation among Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), European Kidney Function Consortium, Revised Lund-Malmö 2011, and Caucasian, Asian, Pediatric and Adult 2014 eGFR equations [10]. The lower performance of CKD-EPI eGFR equations was attributed to differences in population characteristics and measurement methods and suggested that implementing eGFR SCR equations would require a trade-off between accuracy and uniformity across regions. ...

Reference:

Serum Creatinine, Cystatin C, and Combined eGFRs in High-Risk CKD Patients

... While cystatin-based equations have shown promise in improving accuracy and reducing racial bias, creatinine remains widely used due to its accessibility and costeffectiveness. A recent study of >4000 adults indicated that both REFIT and EKFC are effective depending on the population being evaluated [22]. ...

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Performance of the 2021 Estimated Glomerular Filtration Rate CKD-EPI Refit and the European Kidney Function Consortium (EKFC) Formulas

... This is consistent with the findings of a meta-analysis involving participants from the multinational CKD Prognosis Consortium, which showed that a diagnosis of CKD stage 4 (eGFR 15-29 ml/min/1.73 m 2 ) was strongly associated (HR > 280) with kidney failure requiring kidney replacement therapy among patients with or without albuminuria [34]. Additionally, the dispensation of potassium-removing resins and potassium-binding agents was associated with both the kidney failure/need for dialysis and worsening of CKD stage outcomes. ...

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Associations between intercurrent events and cardiorenal clinical outcomes in non-diabetic chronic kidney disease: a real-world retrospective cohort study in the United States

... This could be due to the fact that these markers do not have the same non-GFR determinants or are at least partially independent of each other, so simultaneous use reduces the errors associated with each marker individually. Adingwupu et al. [58] conducted a systematic review that included 26 studies published between 2011 and 2023. The studies assessed mGFR and used a standardized assay for laboratory cystatin C and creatinine measurement in clinical populations with cancer, HIV, cirrhosis and liver transplant, heart failure, neuromuscular disease, and obesity. ...

Reference:

The Use of Cystatin C as a Marker of Glomerular Filtration Rate in Clinical Practice