Diabetic Nephropathy
(Diabetic Kidney disease)
Diabetic kidney disease.
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Diabetic Kidney disease is a major cause of disability and premature death, in diabetic patients. |
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It is a multistage condition that requires many years before becoming clinically overt (clinically manifested) |
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Moderate renal impairment (microalbuminuria) in a NIDDM (Non Insulin Dependent Diabetes Mellitus) is associated with a marked increase in cardiovascular death, or disability and poor quality of life. |
Stages of diabetic kidney diseases:
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Incipient nephropathy (sub clinical-not manifested clinically). |
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Clinical (overt) nephropathy. |
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Advanced nephropathy. |
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End stage renal disease. |
Incipient nephropathy (sub clinical-not manifested clinically)
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Defined as the stage of a persistent increase above normal in the urinary albumin excretion rate, also known as microalbuminuria, in the absence of frank proteinuria (dipstick positive). May be accompanied by hypertension. |
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Incipient diabetic nephropathy (diabetic micro albuminuria) should only be diagnosed when seen to be present on repeat testing and when other causes of raised urinary albumin have been excluded. |
Clinical (overt) nephropathy:
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Defined as the presence of persistent proteinuria (>200ug/minute or >300mg/24 hours); and is usually accompanied by hypertension. |
Advanced nephropathy:
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In advanced nephropathy, there is a significant deterioration of renal function, with a severe decline in GFR (Glomerular filtration rate of kidneys) and the appearance of symptoms of uremia (symptoms due to rise in blood levels of toxic substances not excreted by failing kidneys) and /or nephrotic syndrome (generalized swelling in body) |
End stage renal disease:
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This stage necessitates dialysis or renal transplant. |
Microalbuminuria.
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Incipient nephropathy is the stage of microalbuminuria; | ||||
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Microalbuminuria is defined as albumin (one of the proteins) excretion rate:
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Testing for microalbuminuria should be:
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Done at the time of diagnosis in all patients and at yearly intervals thereafter. |
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Done only if urine is dipstick negative. |
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If negative, repeat annually. |
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If positive, rule out other causes of raised urinary albumin excretion, and confirm ,by rechecking 2-3 times within a 6 months period. |
Methods for testing urinary albumin excretion.
Albumin excretion can be estimated through the following methods:
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24 hours urine collecting. |
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Timed collection, say over a period of 4 hours. |
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Spot urinary sample. |
The results are analyzed as follows
24 hour collection
Timed collection
Spot
collection
mg /24 hours
ug/min
ug/mg Creatinine
Normal
<30
<20
<30
Microalbuminuria
30-300
20-200
30-300
Clinical Albuminuria
>300
>200
>300
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Urinary albumin excretion (UAE) has a marked intra-individual day to day variation which may be up to 50% thus, in patients with an increase in the urinary albumin excretion rate, or a persistent proteinuria, the UAE should be measured in sterile urine on 3 different intervals over a 4-6 month period; |
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Other condition which lead to an increase in UAE should be ruled out; more than 30% patients with raised UAE and/or persistent proteinuria may have an extra renal cause |
Note:
If incipient / clinical diabetic nephropathy is confirmed perform renal function test (Serum Creatinine, urea etc.) and proceed as follows:
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Serum Creatinine normal or slightly raised: Repeat renal tests every 4-6 months. |
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Serum Creatinine moderately raised: Initiate joint care with renal team. |
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Serum Creatinine significantly raised: Prompt referral to renal team. |
Diabetes and Kidney Disease
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A patient who has diabetes runs a greater risk of developing kidney disease, especially if the diabetes started before the patient was 20 years old. |
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Diabetes can cause vascular changes that can affect the kidneys' function; they become less and less able to process and metabolize carbohydrates, proteins, fats, and insulin. |
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The level of kidney function usually decreases gradually until the kidneys stop functioning altogether. |
To help prevent the loss of kidney function,
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It is important that you prevent high blood pressure and maintain good control of your blood sugar level. |
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The more your blood sugar level fluctuates, the harder your kidneys have to work. |
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Keep your blood sugar at the level that your doctor prescribes, and you will help slow kidney deterioration. |