From the Guidelines
Fluid flow shear stress plays a crucial role in the development of glomerular hypertrophy, and its effects can be mitigated by controlling blood pressure and proteinuria through the use of ACEi or ARB, as recommended by the KDIGO 2021 guideline for the management of glomerular diseases 1. The relationship between fluid flow shear stress and glomerular hypertrophy is complex and involves various mechanobiological pathways. Shear stress occurs when blood flows through the glomerular capillaries, creating frictional forces against the endothelial cells lining these vessels. In normal physiological conditions, these forces help maintain glomerular structure and function. However, when blood pressure increases or flow patterns become abnormal, the resulting elevated shear stress triggers signaling cascades in podocytes and endothelial cells that promote hypertrophy. Some studies suggest that high salt intake may also accelerate kidney injury by amplifying glomerular hypertrophy with weight gain, as seen in animal models of renal mass reduction 1. However, the most recent and highest quality study on the management of glomerular diseases recommends controlling blood pressure and proteinuria as the primary approach to mitigating glomerular hypertrophy 1. Key factors that contribute to glomerular hypertrophy include:
- Elevated blood pressure
- Abnormal flow patterns
- High salt intake
- Proteinuria The KDIGO 2021 guideline recommends the use of ACEi or ARB to control blood pressure and proteinuria, with a target systolic blood pressure of <120 mm Hg in most adult patients 1. Additionally, lifestyle modifications such as sodium restriction and potassium supplementation can help reduce serum potassium levels and allow for the use of RAS inhibitors for blood pressure control and proteinuria reduction. In terms of specific treatment approaches, the guideline recommends:
- Using ACEi or ARB as first-line treatment for patients with hypertension and proteinuria
- Uptitrating ACEi or ARB to maximally tolerated or allowed daily dose
- Advising patients on sodium restriction and counseling them to hold RAS inhibitors and diuretics if they are at risk for volume depletion
- Treating metabolic acidosis if serum bicarbonate is <22 mmol/l
- Employing lifestyle modifications to improve control of hypertension and proteinuria in all patients with glomerular disease.
From the Research
Effects of Fluid Flow Shear Stress on Glomerular Hypertrophy
- The provided studies do not directly address the effects of fluid flow shear stress on glomerular hypertrophy.
- However, some studies discuss the relationship between glomerular hypertension, hyperfiltration, and hypertrophy 2.
- Glomerular hyperfiltration can lead to glomerular hypertension, which may cause glomerular hypertrophy 2.
- The renin-angiotensin-aldosterone system (RAAS) plays a crucial role in regulating glomerular pressure and flow, and its inhibition can help reduce glomerular hypertension and hypertrophy 3, 4.
- The use of angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) can help reduce glomerular pressure and slow the progression of kidney disease 3, 4.
- There is limited information available on the specific effects of fluid flow shear stress on glomerular hypertrophy, and further research is needed to fully understand this relationship.