Glomerular hyperfiltration
Glomerular hyperfiltration is when the kidneys’ filtering units (glomeruli) work harder than normal and produce more filtrate. It can occur in various conditions, especially diabetic kidney disease, but there is no single agreed definition. GFR (how fast the kidneys filter) changes with age and other factors, which makes a universal cutoff difficult.
What causes it?
- Efferent arteriolar constriction (via the renin–angiotensin–aldosterone system) raises pressure inside the glomeruli.
- Afferent arteriolar dilation (as in diabetes or after a high-protein meal) increases blood flow into the glomeruli.
- In healthy people, high-protein intake can temporarily raise GFR.
Who gets it?
- Many young people with Type 1 diabetes show hyperfiltration.
- It has also been seen in early hypertension during sympathetic nervous system activation.
Why it matters:
- Hyperfiltration is linked to a higher risk of albumin in the urine and faster progression of diabetic kidney disease, especially if blood sugar control is poor.
- The underlying disease influences how hyperfiltration occurs and what it means for kidney health.
What researchers are finding:
- Activation of RAAS can contribute to kidney injury by harming blood vessel function and arterial health.
- Some possible protective factors are being studied, such as proinsulin C-peptide, which may narrow the afferent arteriole, and rosiglitazone, which may improve blood vessel function and reduce hyperfiltration in early type 2 diabetes.
- In animal studies, nerves to the kidney may play a role; removing these nerves can reduce hyperfiltration in some models.
This page was last edited on 3 February 2026, at 11:59 (CET).