Proliferative diabetic retinopathy in patients with type 2 diabetes correlates with the presence of atherosclerosis cardiovascular disease

Abstract
Atherosclerosis cardiovascular disease (ASCVD) is the main cause of morbidity and mortality in type 2 diabetes mellitus (T2DM). As most diabetic patients with ASCVD are asymptomatic, it is most neglected in clinical practice. For this reason, identifying high-risk ASCVD population with intensified treatment is very important. In recent years, the relationship between diabetic retinopathy (DR) and ASCVD has caused much academic concern, but the results are inconsistent. Moreover, whether all grades of DR increase the risk of ASCVD remains controversial. Most importantly, very few data can be found in China. Our aim is to discuss whether all grades of DR increase the risk of ASCVD after adjustment for the traditional cardiovascular risk factors and to assess the independent contribution of DR to cardiovascular events in patients with T2DM, hoping to provide more evidence for early identification of ASCVD. A total of 425 T2DM patients with complete physical and biochemical data were included in the study. The grade of DR was assessed with two 45 color digital retinal images. Based on the presence of history of ASCVD, 425 T2DM patients were divided into 2 groups: ASCVD group and non-ASCVD group. ASCVD patients were older and had a significantly higher fasting plasma glucose (FPG) and glycated haemoglobin (HbA1c) and proportion of history of ASCVD. At the same time, they were more likely to be females, and had lower level of alcohol and calculated glomerular filtration rate (eGFR) than non-ASCVD patients. Their trend to develop DR with ASCVD was significantly higher than patients with non-ASCVD (χ2 = 5.805, P = 0.016). DR was an independent statistical indicator of the presence of ASCVD [odds ratio (OR) (95% CI): 2.321 (1.152–4.678), P = 0.018]. Furthermore, when DR was divided into non-proliferative retinopathy (NPDR) and proliferative retinopathy (PDR) according to its severity, only PDR was significantly associated with incident ASCVD [OR (95% CI): 8.333 (1.813–38.304), P = 0.006]. After adjusting for traditional ASCVD risk factors, such an association still existed [OR (95% CI): 7.466 (1.355–41.137), P = 0.021]. DR associates strongly with ASCVD in the Chinese population with T2DM. With the increasing severity of DR, the risk of ASCVD also increases. After adjustment for traditional risk factors, PDR is still an independent risk marker for ASCVD.