Diabetic nephropathy

Approximately 20% to 40% of patients with type 1 or type 2 diabetes mellitus develop diabetic kidney disease.

This clinical syndrome characterized by:Persistent albuminuria (> 300 mg/24 h, or > 300 mg/g creatinine)Relentless decline in glomerular filtration rate (GFR)Raised arterial blood pressureEnhanced cardiovascular morbidity and mortality.There is a characteristic histopathology.

In classical diabetic nephropathy:

the first clinical sign is moderately increased urine albumin excretion (microalbuminuria: 30–300 mg/24 h, or 30–300 mg/g creatinine; albuminuria grade A2).Untreated microalbuminuria will gradually worsen, reaching clinical proteinuria or severely increased albuminuria (albuminuria grade A3) over 5 to 15 years.The GFR then begins to decline, and without treatment, end stage kidney failure is likely to result in 5 to 7 years.Although albuminuria is the first sign of diabetic nephropathy, the first symptom is usually peripheral edema, which occurs at a very late stage.Regular, systematic screening for diabetic kidney disease is needed in order to identify patients at risk of or with presymptomatic diabetic kidney disease.Annual monitoring of urinary albumin-to-creatinine ratio, estimated GFR, and blood pressure is recommended.

Stage of diabetic nephropathy

1. Stage One
   • manifests by renal hyperperfusion and hypertrophy
   • This stage starts with the onset of diabetes before insulin treatment.
   • Changes are at least partly reversible by insulin treatment.
   • Glomerular filtration rate is increased due to hyperperfusion
2. Stage Two
   • Characterized by clinical silence and morphologic changes characteristic of diabetic glomerulosclerosis.
   • Glomerular filtration rate (GFR) is still higher than normal during this stage.
   • During good diabetes control, abumin excretion is normal
   • physical exercise unmasks changes in albuminuria not demonstrable in the resting situation.
   • During poor diabetes control albumin excretion goes up both at rest and during exercise
   • Some diabetic patients continue in this stage throughout their lives.
3. Stage Three
   • Microalbuminuria is the salient feature, also called the stage of incipient nephropathy
   • It defined as UAE >30 mg/d, >20 μg/min, or albumin:creatinine ratio (ACR) >30 mg/g creatinine.
   • This stage is initially associated with increased GFR.
   • GFR starts a consistent decline that becomes more evident with the continuous increase of UAE above 300 mg/d, 200 μg/min, or when ACR exceeds 300 mg/g.
4. Stage Four
   • This is the stage of overt nephropathy.
   • Progressive increase in blood pressure is usually associated with these renal changes.
   • When the associated high blood pressure is left untreated, renal function declines,
   • the mean fall rate being around 1 ml/min/mo.
   • Long-term antihypertensive treatment reduces the fall rate by about 60% 7 and thus postpones uremia considerably.
5. Stage Five
   • Itis End Stage Kidney Failure with uremia due to diabetic nephropathy.
   • As many as 25% of the population presently have end-stage kidney failure

Management of diabetic nephropathy

1. Control of blood pressure
2. Control of blood sugar
3. Quitting smoking
4. Diet control: Dietary salt restriction
5. Hypolipidemic treatment
6. Treatment of hyperuricemia
7. Phosphate handling