[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Kidney](https://durgical.com/en/general-pathology/areas/kidney/) › Diabetic nephropathy

# Diabetic nephropathy

- Lesion

High glucose slowly thickens basement membranes and fills the mesangium with matrix; diabetes is the top cause of kidney failure.

Updated Nov 12, 2026

## Key points

- First lesion: GBM thickening (EM), then diffuse mesangial sclerosis, then nodular glomerulosclerosis (Kimmelstiel-Wilson).
- Hyaline arteriolosclerosis of afferent AND efferent arterioles is characteristic.
- Clinical course: hyperfiltration, microalbuminuria, overt proteinuria, falling GFR.
- Insudative lesions: fibrin caps and capsular drops.
- Other renal problems in diabetes: pyelonephritis, papillary necrosis, contrast and drug injury.

## What it is

Diabetic kidney disease develops over years in both type 1 and type 2 diabetes. Advanced glycation end products, glomerular hyperfiltration, angiotensin II and TGF-β drive matrix build-up in basement membranes and mesangium, while hyaline arteriolosclerosis narrows both afferent and efferent arterioles. The disease also makes the kidney prone to pyelonephritis and papillary necrosis.

## Structure

- Kidneys normal or large early, finely granular and small late.
- Kimmelstiel-Wilson nodules: round, PAS-positive acellular matrix balls at the periphery of the tuft, often with microaneurysms.
- IF: linear staining for IgG and albumin along membranes from nonspecific trapping, not immune deposits.
- Tubular basement membranes thicken and the interstitium scars; Armanni-Ebstein glycogen vacuoles in tubules with marked hyperglycemia.

## Step by step

- Chronic hyperglycemia glycates matrix proteins and forms advanced glycation end products.
- Efferent arteriole constriction by angiotensin II and hyperfiltration raise glomerular pressure.
- Mesangial cells, stimulated by TGF-β, make excess collagen IV and matrix; the GBM thickens.
- Podocytes are lost and albumin starts to leak (moderately increased albuminuria).
- Mesangial expansion compresses capillaries and forms nodules; proteinuria grows.
- Hyaline arterioles, sclerosed glomeruli and interstitial fibrosis reduce GFR to end-stage disease.

## Clinical notes

- Annual screening for urine albumin and eGFR in diabetes detects disease early.
- Retinopathy usually coexists; its absence with nephrotic proteinuria should prompt a search for another glomerular disease.

## Memory aid

Sugar coats the membranes, packs the mesangium into nodules and glazes both arterioles.

## Test yourself

Think of the answer, then tap the question to see it.

## What is the earliest morphologic change of diabetic nephropathy?

Thickening of the glomerular basement membrane, visible by electron microscopy.

## What are Kimmelstiel-Wilson lesions?

Nodules of PAS-positive mesangial matrix at the periphery of the glomerular tuft in diabetes.

## Which arterioles show hyalinosis in diabetes?

Both afferent and efferent arterioles; hypertension mainly affects the afferent.

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## Elsewhere in DurgiPedia

- [Physiology of diabetes and ketoacidosis](https://durgical.com/en/physiology/physiology-of-diabetes-and-ketoacidosis/)

## Connections

## Related 5

- [Patterns of glomerular injury](https://durgical.com/en/general-pathology/patterns-of-glomerular-injury/)
- [Hypertensive nephrosclerosis: benign vs malignant](https://durgical.com/en/general-pathology/hypertensive-nephrosclerosis-benign-vs-malignant/)
- [Chronic kidney disease and uremia](https://durgical.com/en/general-pathology/chronic-kidney-disease-and-uremia/)
- [Acute pyelonephritis](https://durgical.com/en/general-pathology/acute-pyelonephritis/)
- [Arteriosclerosis: the three patterns](https://durgical.com/en/general-pathology/arteriosclerosis-the-three-patterns/)

## Related conditions 6

- [Diabetic kidney disease](https://durgical.com/en/conditions/diabetic-kidney-disease/)
- [Type 1 diabetes mellitus](https://durgical.com/en/conditions/type-1-diabetes-mellitus/)
- [Type 2 diabetes mellitus](https://durgical.com/en/conditions/type-2-diabetes-mellitus/)
- [Renal papillary necrosis](https://durgical.com/en/conditions/renal-papillary-necrosis/)
- [Chronic kidney disease](https://durgical.com/en/conditions/chronic-kidney-disease/)
- [Acute pyelonephritis](https://durgical.com/en/conditions/acute-pyelonephritis/)

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Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Diabetes and kidney disease: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000494.htm) (MedlinePlus, US National Library of Medicine, 2025); [Chronic Kidney Disease](https://www.ncbi.nlm.nih.gov/books/NBK535404/) (StatPearls (NCBI Bookshelf), 2024).

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Representative model, for educational purposes only.

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License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/diabetic-nephropathy/