Relationship between dyslipidemia and diabetic retinopathy in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

Abstract

Background Diabetic retinopathy (DR) affects more than 80% of patients with diabetes. However, literature on the association between serum lipids and DR in patients with type 2 diabetes mellitus (T2DM) is inconsistent. Hence, in this study, we aimed to investigate the relationship between baseline serum lipids and the incidence of DR in patients with T2DM. Methods We searched relevant articles in the PubMed, Embase databases, and the Cochrane Library up to February 7, 2022, and reviewed the reference lists of the included articles to identify appropriate cohort studies. The weighted mean difference (WMD) and the corresponding 95% confidence intervals (CIs) were calculated. Results Thirteen cohort studies, including 7459 participants, were included in the present study. Higher levels of total cholesterol (2.94 mg/dL, 95% CI 1.32, 4.56), triglycerides (8.13 mg/dL, 95% CI 5.59, 10.66), and low-density lipoprotein cholesterol (2.53 mg/dL, 95% CI 1.02, 4.04) at baseline were observed in patients with later onset of DR. However, no significant difference in the high-density lipoprotein cholesterol level (0.27 mg/dL, 95% CI − 0.91, 1.45) was observed between patients with DR and without DR. Conclusion The present results suggest that baseline triglyceride and cholesterol levels are significantly associated with the occurrence of DR in patients with T2DM. Thus, patients with T2DM may benefit from lowering serum lipids. Future studies exploring the relationship between longitudinal changes in serum lipids and DR occurrence are warranted. Systematic review registration PROSPERO CRD42022319978

Causal relationships between blood metabolites and diabetic retinopathy: a two-sample Mendelian randomization study

“…The above criteria have been applied in previous literatures ( 18 , 20 ). In addition, we examined these SNPs on the Phenoscanner V2 website ( http://www.phenoscanner.medschl.cam.ac.uk/ ) to evaluate whether they are related to common confounders for DR, such as Type 1 Diabetes ( 5 ), Type 2 Diabetes (T2D) ( 21 ), Diabetic nephropathy (DN) ( 22 ), HbA1c ( 6 ), blood pressure ( 8 ), fasting glucose ( 6 ), fasting insulin ( 23 ), Total Cholesterol ( 7 ), Body Mass Index ( 24 ) and smoking ( 25 ). SNPs related to the above confounders ( p < 1×10 –5 ) were excluded to satisfy the MR assumptions.…”

“…The pathogenesis of DR is complex and includes multiple contributing factors such as oxidative stress, inflammation, angiogenesis, intestinal flora dysregulation, and neurodegeneration ( 4 ). Common risk factors for DR include diabetes course ( 5 ), elevated blood glucose levels ( 6 ), high lipid levels ( 7 ), and hypertension ( 8 ). Despite the extensive research conducted on DR, the mechanisms and risk factors for DR are still not fully understood.…”

Influence of Serum Lipid Levels on the Retinal Neural Tissue in Diabetes

“…progression and serum lipids, indicating elevated serum levels of LDLC, TG, and TC in patients with DR 29 . Moreover, Mondal et al reported that LDLC levels were 18 , and Zhang et al reported that LDLC and TC levels were 30 associated with intraocular VEGF levels.…”

Genetic Association between Lipid-Regulating Drug Targets and Diabetic Retinopathy: A Drug Target Mendelian Randomization Study

“…Some epidemiological studies found no significant association between total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and DR development [ 11 , 12 ]. But other studies observed that triglyceride (TG) and TC levels were significantly associated with DR risk in diabetic patients [ 13 , 14 ]. These discrepant findings could be attributed to measurement errors, uncontrolled confounders, and reverse causality in epidemiological studies [ 15 ], which can induce spurious associations or mask the real risk factors [ 16 ].…”