Glomerular Filtration Rate

Prognostic significance of GFR

Estimated GFR (eGFR) combined with the baseline severity of albuminuria or proteinuria allows the physician to accurately stratify risk. According to large-scale meta-analyses (over a million observations over the past 10 years), a decrease in eGFR serves as an independent predictor of adverse outcomes. Among the main threats are increased overall mortality, the development of end-stage renal disease (ESRD), and acute kidney injury (AKI). Regular dynamic assessment of these parameters during treatment is absolutely essential for proper treatment planning.

Choice of therapeutic strategy

The treatment strategy is strictly tied to the assessment of the risk of progression of renal failure, which largely depends on the GFR level.

• Non-intervention strategy: Indicated for patients with isolated hematuria. Specific treatment is not required here; dynamic observation is sufficient.
• Nephroprotective therapy: Recommended for individuals with moderate risk. It is prescribed in the presence of hematuria (including synpharyngitic episodes) combined with mild proteinuria (ranging from 0.5 to 1 g/day). A mandatory clinical condition for starting such therapy is the preservation of normal GFR and the complete absence of arterial hypertension.

Impact of blood pressure control

In real-world clinical practice, the initiation of intensive blood pressure control is often accompanied by a paradoxical worsening of laboratory parameters. In almost half of patients (up to 46%), the early stages of therapy show a decrease in GFR and a simultaneous increase in serum creatinine levels.

A particular hazard is a decrease in systolic blood pressure (SBP) below 120 mm Hg. It has been proven that such changes are reliably associated with adverse renal outcomes.

Consequences of renal hypoperfusion

A decrease in systemic pressure and a drop in glomerular filtration pressure trigger a cascade of dangerous pathological changes, creating a state of hypoperfusion:

1. The vulnerability of renal tissue to any external aggressive factors, including pharmacological interventions, sharply increases.
2. The probability of developing AKI increases manifold.
3. The rate of progression of chronic kidney disease (CKD) increases.

Ultimately, the hypoperfusion scenario can completely neutralize all expected positive effects of the ongoing therapy.

Point-based risk assessment

In modern prognostic systems, the severity of dysfunction and the risk of progression are formalized in points:

• A decrease in estimated or measured GFR of less than 50% gives 1 point.
• The presence of massive proteinuria (more than 3.5 g/day) is also assessed as 1 point.
• The development of end-stage renal disease (regardless of whether hemodialysis is performed or transplantation has been done) immediately yields 3 points.

Class and exam questions

What else to study on this topic

• Pathogenesis and markers of acute kidney injury (AKI)
• Mechanisms of chronic kidney disease (CKD) progression
• Principles of nephroprotective therapy in moderate risk
• Synpharyngitic hematuria: clinical significance
• End-stage renal disease: criteria and assessment

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.