Microalbuminuria in type 1 diabetes: rates, risk factors and glycemic threshold.
BACKGROUND
The occurrence of microalbuminuria in type 1 diabetes is strongly predictive of renal and cardiovascular disease and is still likely to occur despite improvements in glycemic control. A better understanding of microalbuminuria is required to inform new interventions. We determined the incidence and risk factors for microalbuminuria [albumin excretion rate (AER) 20 to 200 microg/min] in the EURODIAB Prospective Complications Study.


METHODS
This is a seven-year follow-up (between 1988 and 1991) of 1134 normoalbuminuric men and women (aged 15 to 60) with type 1 diabetes from 31 European centers. Risk factors and AER were measured centrally.


RESULTS
The incidence of microalbuminuria was 12.6% over 7.3 years. Independent baseline risk factors were HbA1c (7.1 vs. 6.2%, P = 0.0001) and AER (9.6 vs. 7.8 microg/min, P = 0.0001) and, independent of these, fasting triglyceride (0.99 vs. 0.88 mmol/L, P = 0.01), low-density lipoprotein cholesterol (3.5 vs. 3.2 mmol/L, P = 0.02), body mass index (24.0 vs. 23.4 kg/m2, P = 0.01), and waist to hip ratio (WHR; 0.85 vs. 0.83, P = 0.009). Triglyceride and WHR risk factors were nearly as strong as AER in predicting microalbuminuria (standardized regression effects of 1.3 for triglyceride and WHR and 1.5 for AER). Blood pressure at follow-up, but not at baseline, was also raised in those who progressed. There was no evidence of a threshold of HbA1c on microalbuminuria risk.


CONCLUSIONS
The incidence of microalbuminuria in patients with type 1 diabetes remains high, and there is no apparent glycemic threshold for it. Markers of insulin resistance, such as triglyceride and WHR, are strong risk factors. Systemic blood pressure is not raised prior to the onset of microalbuminuria.
Chaturvedi
N
N
EURODIAB, University College London, London, England, United Kingdom. n.chaturvedi@ic.ac.uk
Bandinelli
S
S
Mangili
R
R
Penno
G
G
Rottiers
R E
RE
Fuller
J H
JH
D000293:Adolescent; D000328:Adult; D000419:Albuminuria / Q000453:epidemiology / Q000652:urine*; D001786:Blood Glucose / Q000378:metabolism*; D001824:Body Constitution; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000652:urine*; D004056:Differential Threshold; D018450:Disease Progression; D005060:Europe; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012016:Reference Values; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D014280:Triglycerides