Markers of insulin resistance are strong risk factors for retinopathy incidence in type 1 diabetes.
OBJECTIVE
To determine the incidence of retinopathy and the relative importance of its risk factors in type 1 diabetes.


METHODS
This is a 7.3-year follow-up of 764 of 1,215 (63%) people with type 1 diabetes across Europe, aged 15-60 years at baseline with no retinopathy (the EURODIAB Prospective Complications Study). Retinal photographs were taken at baseline and follow-up and risk factors were assessed to a standard protocol.


RESULTS
Retinopathy incidence was 56% (429/764, 95% CI 52-59%). Key risk factors included diabetes duration and glycemic control. We found no evidence of a threshold effect for HbA1c on retinopathy incidence. Univariate associations were observed between incidence and albumin excretion rate, cholesterol, triglyceride, fibrinogen, von Willebrand factor, gamma-glutamyltransferase, waist-to-hip ratio, and insulin dose. No associations were observed for blood pressure, cardiovascular disease, or smoking. Independent risk factors, as assessed by standardized regression effects, were HbA1C (1.93, P = 0.0001), duration (1.32, P = 0.008), waist-to-hip ratio (1.32, P = 0.01), and fasting triglyceride (1.24, P = 0.04).


CONCLUSIONS
Retinopathy incidence in type 1 diabetes remains high. Key risk factors include diabetes duration and glycemic control, with no evidence of a threshold for the latter. Other independent risk factors, such as waist-to-hip ratio and triglyceride levels, both markers of insulin resistance, were strongly related to incidence.
Chaturvedi
N
N
EURODIAB Prospective Complications Study, University College London, UK. n.chaturvedi@ic.ac.uk
Sjoelie
A K
AK
Porta
M
M
Aldington
S J
SJ
Fuller
J H
JH
Songini
M
M
Kohner
E M
EM
D000293:Adolescent; D000328:Adult; D000419:Albuminuria; D015415:Biomarkers / Q000032:analysis*; D001824:Body Constitution; D002784:Cholesterol / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000188:drug therapy; D003930:Diabetic Retinopathy / Q000175:diagnosis* / Q000453:epidemiology; D005215:Fasting; D005340:Fibrinogen / Q000032:analysis; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007328:Insulin / Q000008:administration & dosage; D007333:Insulin Resistance; D016015:Logistic Models; D008875:Middle Aged; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D005723:gamma-Glutamyltransferase / Q000097:blood; D014841:von Willebrand Factor / Q000032:analysis
D015415:Biomarkers; D002784:Cholesterol; D005340:Fibrinogen; D006442:Glycated Hemoglobin; D007328:Insulin; D014280:Triglycerides; D005723:gamma-Glutamyltransferase; D014841:von Willebrand Factor