Predictive value of microalbuminuria in patients with insulin-dependent diabetes of long duration.
OBJECTIVE
To investigate the predictive value of microalbuminuria (albumin excretion rate 30-300 mg/24 h) as a risk factor for overt diabetic nephropathy in patients with longstanding insulin dependent diabetes.


METHODS
10 year follow up of patients with normoalbuminuria (albumin excretion rate < 30 mg/24 h), microalbuminuria (30-300 mg/24 h), and macroalbuminuria (> 300 mg/24 h) based on two out of three timed overnight urine samples.


METHODS
Outpatient clinic of Helsinki University Hospital.


METHODS
72 consecutive patients who had had insulin dependent diabetes for over 15 years.


METHODS
Urinary albumin excretion rate, mortality, and prevalence of diabetic complications after 10 years.


RESULTS
56 patients were re-examined at 10 year follow up, 10 had died, five were lost to follow up, and one was excluded because of non-diabetic kidney disease. At initial screening 22 patients had macroalbuminuria, 18 had microalbuminuria, and 26 had normal albumin excretion. Only five (28%, 95% confidence interval 10% to 54%) of the microalbuminuric patients developed macroalbuminuria during the 10 year follow up and none developed end stage renal failure. Two (8%, 1% to 25%) normoalbuminuric patients developed macroalbuminuria and four (15%, 4% to 35%) became microalbuminuric. Seven (32%, 14% to 55%) of the macroalbuminuric patients developed end stage renal failure and six (27%, 11% to 50%) died of cardiovascular complications.


CONCLUSIONS
Microalbuminuria is not a good predictor of progression to overt nephropathy in patients with longstanding insulin dependent diabetes.
Forsblom
C M
CM
Fourth Department of Medicine, Helsinki University Hospital, Finland.
Groop
P H
PH
Ekstrand
A
A
Groop
L C
LC
D000328:Adult; D000419:Albuminuria / Q000150:complications*; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000652:urine; D003928:Diabetic Nephropathies / Q000209:etiology* / Q000652:urine; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors