DIABETIC KIDNEY DISEASE
Diabetic kidney disease is a major caused of morbidity
and premature death, in diabetic patients.
It is multistage condition that requires many years before becoming clinically
An estimated 5% to 15% of DM 2 cases also progress through the five stages
of diabetic nephropathy (DN), but the timeline is not as clear. Some patients
advance through the stages very quickly.
For a chart on the five stages associated with diabetic nephropathy
and the albumin excretion, GFR and BP at each stage see Appendix 11a
Risk factors for the development of diabetic nephropathy are:
|Raised blood pressure
|Baseline urinary albumin excretion
|Duration of diabetes
|Presence of retinopathy
|Raised cholesterol and triglyceride levels
|Raised serum homocysteine levels.
Incipient nephropathy is the stage of microalbuminuria;
Albumin excretion can be estimated through the following methods:
- 24 hour urine collection.
- Timed collection, say over a period of four hours.
- Spot urinary sample
The results are analysed as follows:
||24 hour collection
||mg / 24 hours
||ug / min
||30 - 300
||20 - 200
||30 - 300
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;
Albumin to creatinine ratio >30mg/g in an untimed urine specimen is
a good predictor of the development of overt nephropathy during an 8 year
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;
For a partial list of common "non diabetic" causes of raised
urinary albumin excretion see Appendix 11b
|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
If tests for microalbuminuria are negative, RETEST
|MANAGEMENT strategies for microalbuminuria
- Meticulous glycemic control.
- Exclude other causes for microalbuminuria
- Meticulous control of blood pressure and dyslipidemias, if present.
- Avoid dehydration.
- Prompt diagnosis and meticulous management of urinary tract infections.
- Use of ACE inhibitors (ACEIs) even in normotensive patients. Angiotensin
Receptor Blockers (ARBs) used alone or in combination with ACEIs seem
to be a better alternative, but more studies are necessary before this
recommendation can be made as routine therapy.
|MANAGEMENT strategies in clinical
- meticulous glycemic control.
- tight control of blood pressure, with the aim to maintain the BP
as close to 120/80 as possible, although this needs to be individualised
i.e., older patients may have more leeway;
- cessation of smoking.
- salt restriction.
- protein restriction (0.4.0.6mg/kg/day).
- treat associated lipid disorders.
- check for urinary tract infection; exclude other causes for renal
- avoid dehydration.
- caution against use of drugs which harm renal function and radio
graphic dyes; this should always be done in any diabetic, but all the
more in patients with clinical nephropathy.
End Stage Renal Disease
Renal replacement therapy (dialysis and / or
renal transplant) is the treatment for end stage renal disease (ESRD).