Deciphering the eGFR Enigma: Unveiling the Critical Role and Inherent Limitations in Kidney Disease Assessment

Written by

Dr. Deepak Sharma

BHMS, MD, Ph.D. (Scholar)

Homeopathic Physician and Educator

Founder – Orbit Clinics (World Class Homeopathic Clinics Worldwide)

Introduction:

The estimated glomerular filtration rate (eGFR) is an essential tool used in the assessment and monitoring of kidney function. It plays a pivotal role in diagnosing, staging, and evaluating the progression of kidney disease. Although it provides significant insight into kidney health, there are inherent limitations to the eGFR test. This article explores the actual role of eGFR in kidney disease, its significance, and the limitations of the test.

The Actual Role of eGFR in Kidney Disease:

1. Diagnosis and staging of kidney disease

eGFR is a measure of kidney function, specifically the rate at which the kidneys filter waste and excess fluid from the blood. It is derived from serum creatinine levels, a byproduct of muscle metabolism, which is filtered by the kidneys. Elevated serum creatinine levels indicate a decrease in kidney function. Using eGFR, clinicians can diagnose and stage chronic kidney disease (CKD) according to the Kidney Disease Improving Global Outcomes (KDIGO) guidelines, with stages ranging from G1 (normal kidney function) to G5 (kidney failure).

2. Monitoring progression

Regular monitoring of eGFR is essential for assessing the progression of kidney disease over time. A declining eGFR indicates a deterioration in kidney function, and may prompt further investigations and interventions. eGFR is also useful in determining the effectiveness of treatments and guiding decisions about medication dosages.

3. Identifying complications

An abnormal eGFR may signal the development of kidney-related complications, such as anemia or bone disorders. Early detection of these issues allows for prompt management to minimize the impact on the patient’s overall health.

The Significance of eGFR in Kidney Disease:

1. Early detection and intervention

The use of eGFR in routine blood tests enables the early detection of kidney disease, which is crucial as many people remain asymptomatic until the later stages of the disease. Early identification allows for timely intervention, which can slow the progression of kidney disease, reducing the risk of complications and the need for dialysis or transplantation.

2. Personalized treatment plans

eGFR results help clinicians tailor treatment plans to the patient’s specific needs. Adjusting medication dosages, introducing new treatments, and implementing lifestyle changes based on eGFR results can improve outcomes and quality of life for individuals with kidney disease.

3. Prognosis and risk stratification

eGFR values serve as a prognostic tool, helping healthcare providers determine a patient’s risk of adverse outcomes, such as cardiovascular events or progression to kidney failure. This information is valuable in guiding decisions about the aggressiveness of interventions and monitoring frequency.

Normal Range of eGFR:

Incorporating the normal range of eGFR is crucial to understanding the test’s significance in assessing kidney function. The normal range of eGFR for adults is generally considered to be between 90 and 120 mL/min/1.73 m². However, it is essential to note that the normal range can vary depending on factors such as age, sex, and ethnicity. For instance, eGFR may be slightly lower in older individuals and in certain racial and ethnic groups.

Risk Factors for Increased eGFR:

While eGFR is a valuable tool in assessing kidney function, it is essential to recognize that certain risk factors can lead to increased eGFR values, indicating potential problems with kidney function. Understanding these risk factors can help clinicians interpret eGFR results more accurately and guide the appropriate management of patients with kidney disease.

1. Age: As people age, their kidney function naturally declines, which can result in a higher eGFR value. Healthcare providers should consider the patient’s age when interpreting eGFR results and adjust their expectations accordingly.
2. Diabetes: Diabetes is one of the leading causes of kidney disease, and it can contribute to increased eGFR values. High blood sugar levels can damage the blood vessels in the kidneys, impairing their ability to filter waste and toxins effectively.
3. Hypertension: Uncontrolled high blood pressure can damage the blood vessels in the kidneys, leading to increased eGFR values. Hypertension is another significant risk factor for kidney disease, and proper management of blood pressure is crucial in preventing kidney damage.
4. Obesity: Excess body weight can put additional strain on the kidneys and increase the risk of developing kidney disease. Obesity can lead to higher eGFR values, as the kidneys struggle to filter waste and excess fluids effectively.
5. Family history: A family history of kidney disease can increase the risk of developing kidney problems, which may be reflected in higher eGFR values. Healthcare providers should consider the patient’s family history when interpreting eGFR results and assess their overall risk for kidney disease.
6. Autoimmune diseases: Certain autoimmune diseases, such as lupus or IgA nephropathy, can cause inflammation and damage to the kidneys. Patients with autoimmune diseases may have higher eGFR values due to impaired kidney function.
7. Smoking: Smoking is a known risk factor for kidney disease, as it can damage the blood vessels in the kidneys, impairing their ability to filter waste effectively. Smokers may have increased eGFR values due to compromised kidney function.
8. Ethnicity: Some racial and ethnic groups, such as African Americans, Hispanics, and Native Americans, have a higher risk of developing kidney disease. Healthcare providers should consider the patient’s ethnicity when interpreting eGFR results and adjust their expectations accordingly.

Limitations of the eGFR Test:

1. Inaccuracy in certain populations

The eGFR calculation is based on serum creatinine levels, age, sex, and race. However, factors such as muscle mass, diet, and hydration status can also influence serum creatinine levels, potentially leading to inaccurate eGFR results. The eGFR formula may be less accurate in elderly individuals, people with extreme body compositions, and those with rapidly changing kidney function.

2. Lack of standardization

There are several equations for calculating eGFR, including the Modification of Diet in Renal Disease (MDRD) study equation and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Different laboratories and clinical settings may use different equations, which can lead to inconsistencies in eGFR values.

3. Limited insight into the cause of kidney disease

While eGFR is valuable in assessing kidney function, it does not provide information about the underlying cause of kidney disease. Further diagnostic tests, such as imaging studies, kidney biopsy, or blood and urine tests, are necessary to identify the specific etiology and guide targeted treatment strategies.

Overreliance on eGFR Given the limitations of eGFR, healthcare providers should not solely rely on this test to make clinical decisions. A comprehensive assessment, including clinical history, physical examination, and additional diagnostic tests, is crucial for the accurate evaluation and management of kidney disease.

Role of Homeopathy in Kidney Disease Management:

While the article focuses on the role of EGFR in kidney disease, here mentioning the potential role of homeopathy in managing kidney diseases. Homeopathy is a complementary and alternative medicine (CAM) system that uses highly diluted natural substances to stimulate the body’s self-healing mechanisms. Some patients with kidney disease may choose to explore homeopathy as an adjunct to conventional treatments, with the goal of managing symptoms and improving overall well-being.

1. Symptom relief and supportive care Homeopathic remedies may help alleviate certain symptoms associated with kidney diseases, such as fatigue, sleep disturbances, and anxiety. These remedies can provide supportive care alongside conventional treatments, improving the patient’s quality of life.
2. Complementary approach In some cases, homeopathy may be used as a complementary therapy in conjunction with conventional treatments to enhance their effectiveness. It is essential for patients to communicate with their healthcare providers about their use of homeopathic remedies to ensure there are no contraindications or interactions with prescribed medications.
3. Individualized treatment One of the key principles of homeopathy is the individualization of treatment based on the patient’s unique symptom profile. This approach aligns with the concept of personalized medicine, as it aims to tailor the treatment plan to the specific needs and characteristics of the patient.
4. Holistic approach Homeopathy considers the whole person, including physical, emotional, and mental aspects, when selecting a treatment plan. This holistic approach can help address the multidimensional nature of kidney disease, focusing not only on kidney function but also on the overall well-being of the patient.

References:

1. Levey, A. S., Stevens, L. A., Schmid, C. H., Zhang, Y. L., Castro, A. F., Feldman, H. I., … & Coresh, J. (2009). A new equation to estimate glomerular filtration rate. Annals of internal medicine, 150(9), 604-612.
2. Inker, L. A., Astor, B. C., Fox, C. H., Isakova, T., Lash, J. P., Peralta, C. A., … & Feldman, H. I. (2014). KDOQI US commentary on the 2012 KDIGO clinical practice guideline for the evaluation and management of CKD. American Journal of Kidney Diseases, 63(5), 713-735.
3. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. (2013). KDIGO 2012 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney international supplements, 3(1), 1-150.
4. National Kidney Foundation. (2002). K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. American journal of kidney diseases, 39(2 Suppl 1), S1-S266.
5. Levey, A. S., Coresh, J., Balk, E., Kausz, A. T., Levin, A., Steffes, M. W., … & Eknoyan, G. (2003). National Kidney Foundation practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Annals of internal medicine, 139(2), 137-147.
6. Peralta, C. A., Shlipak, M. G., Judd, S., Cushman, M., McClellan, W., Zakai, N. A., … & Safford, M. (2011). Detection of chronic kidney disease with creatinine, cystatin C, and urine albumin-to-creatinine ratio and association with progression to end-stage renal disease and mortality. JAMA, 305(15), 1545-1552.
7. Stevens, L. A., & Levey, A. S. (2009). Measurement of kidney function. Medical Clinics, 93(4), 875-889.
8. Rule, A. D., Bailey, K. R., Schwartz, G. L., Khosla, S., Lieske, J. C., & Melton, L. J. (2009). For estimating creatinine clearance measuring muscle mass gives better results than those based on demographics. Kidney International, 75(10), 1071-1078.
9. Go, A. S., Chertow, G. M., Fan, D., McCulloch, C. E., & Hsu, C. Y. (2004). Chronic kidney disease and the risks of death, cardiovascular events, and hospitalization. New England Journal of Medicine, 351(13), 1296-1305.
10. Bagheri, N., Nemati, R., & Khalkhali, H. R. (2018). The effect of homeopathy on reducing the complications of chronic kidney disease: A systematic review and meta-analysis. Complementary Therapies in Clinical Practice, 32, 83-89.