['The association between lipids and diabetic retinopathy (DR) remains unclear. Only a few studies have reported the association between proliferative diabetic retinopathy (PDR) and the serum concentrations of apolipoprotein A1 (apoA1), apolipoprotein B (apoB) and apolipoprotein E (apoE). So we investigated the lipid profile in type 2 diabetic patients of long duration with very mild nonproliferative diabetic retinopathy (NPDR) or PDR.', 'Serum samples were obtained from 25 type 2 diabetic patients with very mild NPDR and 25 type 2 diabetic patients with PDR, and the two groups were matched by diabetes duration and glycosylated hemoglobin (HbA(1c)) levels. The levels of total cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, apoA1, apoB, and apoE were measured by enzymatic colorimetric, surfactant, and immunotubidimetric method.', "Compared with PDR subjects, very mild NPDR subjects were characterized by increased HDL cholesterol (P\u2009=\u20090.0433) and apoA1 (P\u2009=\u20090.0290) levels, higher HDL cholesterol/LDL cholesterol (P\u2009=\u20090.0377) and apoA1/apoB (P\u2009=\u20090.0061) ratio in serum. There were significant associations between the decreased apoA1 and low apoA1/apoB ratio in serum and PDR. Even after adjustment for age, decreased apoA1 level (P\u2009=\u20090.0304) and low apoA1/apoB ratio (P\u2009=\u20090.0218) in serum were significantly associated with PDR in type 2 diabetic patients of over 15\xa0years' duration."] Is low serum apolipoprotein A1/B ratio associated with proliferative diabetic retinopathy in type 2 diabetes?