Markers of insulin resistance are strong risk factors for retinopathy incidence in type 1 diabetes - The EURODIAB Prospective Complications Study

OBJECTIVE- To determine the incidence of retinopathy and the relative impor tance of its risk factors in type 1 diabetes. RESEARCH DESIGN AND 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 baselin e with no retinopathy (the EURODLAB Prospective Complications Study). Retin al photographs were taken at baseline and follow-up and risk factors were a ssessed to a standard protocol. RESULTS- Retinopathy incidence was 56% (429/764, 95% CI 52-59%). Key risk f actors included diabetes duration and glycemic control. We found no evidenc e of a threshold effect for HbA(1c) on retinopathy incidence. Univariate as sociations were observed between incidence and albumin excretion rate, chol esterol, triglyceride, fibrinogen, von Willebrand factor, gamma -glutamyltr ansferase, waist-to-hip ratio, and insulin dose. No associations were obser ved for blood pressure, cardiovascular disease, or smoking. Independent ris k factors, as assessed by standardized regression effects, were HbA(1c) (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 ris k factors include diabetes duration and glycemic control, with no evidence of a threshold for the latter. other independent risk factors, such as wais t-to-hip ratio and triglyceride levels, both markers of insulin resistance, were strongly related to incidence.