Evaluating the relation between serum apolipoprotein B (apo B), apolipoprotein A (apo A) and apo B/apo A ratio with diabetic retinopathy in a sample of type 2 Egyptian diabetic patient

Abstract

Abstract Background Diabetic retinopathy (DR) is a chronic progressive, ocular disease affecting the retinal microvasculature accompanied by hyperglycaemia and different situations related to diabetes mellitus (DM) such as hypertension (HTN). Till now, the majority of researches demonstrated an insignificant correlation between lipid profile parameters and DR. Novel serum lipid markers (apolipoproteins) which are the protein portion of lipoproteins were recently linked to DR, and observed that the increased apo B and high apo B/apo A ratio accompanied by a higher possibility of proliferative DR. Aim To assess the relation between novel serum lipid markers and various grades of DR in a sample of type 2 Egyptian diabetic cases. Methods This study comprised 80 cases with type 2 diabetes mellitus (T2DM) divided into 3 groups: T2DM cases with proliferative diabetic retinopathy (PDR) (group I), T2DM cases with non-PDR (group II) and T2DM cases without DR as a control group (group III). Fasting plasma glucose (FPG), 2-h postprandial plasma glucose (2hpp), haemoglobinA1c (HbA1c), cholesterol (chol), triglycerides (TG), LDL, HDL and serum apolipoprotein A and B level. Complete medical history was taken from entire cases with a special focus on the duration of HTN and diabetes and full clinical examination (including BP and BMI). Results There was a significant difference regarding serum apo B, apo B/apo A ratio, TG, total chol, LDL (p<0.001*), DM duration (p=0.002), HTN duration (p=0.014), SBP (p=0.006), DBP (p=0.013), BMI (p=0.050) and HbA1c (p=0.025), being higher in group I than group II than group III; also, there was a significant difference between them with regard to serum apo A (p=0.010), and HDL (p=0.047) being higher in group III than group II than group I. On comparing group I with group II using Post hock Tukey’s test there was a significant difference regarding serum apo B (p=.023) and apo B/apo A ratio (p=.002). There was a statistically significant positive correlation between serum apo B/apo A ratio and diabetic duration (r=0.248), HTN d (r=0.4), HbA1c (r=.47), LDL (r=0.68), triglycerides (r=0.52), cholesterol (r=0.70) and a statistically significant negative correlation between serum apo B/apo A ratio and HDL (r=0.37) in all subjects. In addition, HTN duration was demonstrated to be the most independent factor affecting B/A ratio. Conclusion Serum apo B and serum apo B/apo A ratio in diabetic cases are higher in the presence of retinopathy, triglycerides, total cholesterol, LDL, and HDL, and it is also higher in proliferative than non-proliferative diabetic retinopathy. The current study emphasizes on the potential correlation between the high serum apo B, serum apo B/apo A ratio and the advancement of DR.

Keywords

• Serum apolipoprotein B
• Serum apolipoprotein A
• Diabetic retinopathy
• LDL
• HDL
• Cholesterol