Total Serum Cholesterol Increases Risk for Development and Progression of Nonproliferative Retinopathy in Patients with Type 1 Diabetes Without Therapeutic Intervention: Prospective, Observational Study.

INTRODUCTION: Results from studies investigating relationship between serum lipids and risk of development and progression of diabetic retinopathy (DR) in patients with type 1 diabetes (T1DM) are not consistent. The objective of this study was to explore the relationship between serum lipids and risk of development and progression of nonproliferative diabetic retinopathy (NPDR) in T1DM with normal renal function and with no therapeutic intervention that might influence on retinopathy and serum lipids status.

METHODS: A total of 103 T1DM with normal renal function (urinary albumin excretion rate <30 mg/24 h, estimated glomerular filtration rate (eGFR) >60 mL min‒1 1.73m‒2 ), and before any interventions with lipid-lowering therapy, ACE inhibitors or angiotensin II receptor blockers were included in this study and followed for 41 months. Photodocumented retinopathy status was made according to the EURODIAB protocol.

RESULTS: Patients who developed NPDR or progressed to proliferative retinopathy were older (44 vs. 33 years, p <0.001), had longer duration of diabetes (21.1 vs. 13.3 years, p <0.001), and higher serum total cholesterol level (5.1 vs. 4.5 mM/L, p = 0.02) compared to patients without retinopathy. In a backward stepwise Cox's multiple regression analysis serum total cholesterol was significantly associated with risk of development or progression of NPDR in our subjects (p = 0.04), with odds ratios of 1.27-1.91.

CONCLUSION: These data suggest that serum total cholesterol levels are associated with risk of development and progression of NPDR in T1DM and normal renal function. The study was conducted in patients with no therapeutic interventions.