Serum lipid profile in diabetic macular edema

Association between the response of intravitreal antivascular endothelial growth factor injection and systemic factors of diabetic macular edema

BACKGROUND

This study investigated the effects of systemic factors in response to intravitreal injections in patients with macular edema due to non-proliferative diabetic retinopathy (NPDR).

METHODS

We retrospectively reviewed the medical records of patients treated with intravitreal injections for macular edema secondary to NPDR between January 2018 and January 2021. The patients were divided into three groups according to the injection response. When patients with diabetic macular edema showed 20µ or more reduction in central retinal thickness compared to baseline, they were classified as responsive group, and if not, they were classified as refractory group. The responsive group was further divided into the complete and incomplete response groups. Patients with complete disappearance of edema at seven months were classified as the complete response group, whereas those in which edema did not disappear were classified as the incomplete response group. The clinical characteristics of each group, including medical history, ophthalmic examination results, and laboratory examination results at the time of diagnosis, were analyzed.

RESULTS

Of the 112 eyes (91 patients) that satisfied the inclusion criteria, 89 (77 patients) in the responsive group and 23 (14 patients) in the refractory group were included in the analysis. The responsive group was further divided into the complete (51 eyes) and incomplete (38 eyes) response groups. The refractory group had significantly higher glycated hemoglobin levels and significantly lower estimated glomerular filtration rates than the responsive group (p = 0.026 and p = 0.012, respectively). In the multivariate logistic regression analysis, both factors were found to be significant in predicting the degree of response (all p < 0.05). No factor showed a significant difference between the incomplete and complete response groups(all p > 0.05).

CONCLUSIONS

In macular edema caused by NPDR, low glomerular filtration rates and high glycated hemoglobin levels may be used as predictors of poor response to intravitreal injection therapy. In addition to blood glucose control, education should be provided regarding the need for the continuous monitoring of renal function.

Evaluating peripheral blood inflammatory and metabolic biomarkers as predictors in diabetic retinopathy and diabetic macular edema

Purpose

To determine the correlation between serum inflammatory and metabolic biomarkers of patients with diabetic retinopathy (DR) and diabetic macular edema (DME).

Methods

Serum samples were obtained from 100 diabetic patients. Patients were divided into three groups: group 1 (patients with no DR, n = 27), group 2 (DR with DME, n = 34), and group 3 (DR without DME, n = 39). Serum concentrations of C-reactive protein (CRP) and interleukin-6 (IL-6) were measured by quantitative turbidimetric immunoassay and sandwich chemiluminescence immunoassay, respectively. Metabolic parameters such as glycated hemoglobin (HbA1c), total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), serum creatinine, and blood urea were determined by automated analyzer om-360 after standardization.

Results

The levels of IL-6 and CRP differed significantly in patients with DR and without DR (P < 0.001 and P = 0.045, respectively). We also found a positive correlation between IL-6 and CRP with the severity of DR. When DR patients with DME were compared to patients without DME, only IL-6 was observed to be significantly elevated (P < 0.001). None of the metabolic markers correlated significantly with DR and DME.

Conclusion

Significantly raised levels of serum inflammatory biomarkers can be used to elucidate the significant role of inflammation in the pathogenesis of DR. Therefore, circulating biomarkers can serve as diagnostic and therapeutic predictors for monitoring the onset and progression of DR and DME.

Novel insights into the mechanisms of hard exudate in diabetic retinopathy: Findings of serum lipidomic and metabolomics profiling

Objective

Retinal hard exudates (HEs) result from lipoproteins leaking from capillaries into extracellular retinal space, and are related to decreased visual acuity in diabetic retinopathy (DR). This study aims to identify differential serum lipids and metabolites associated with HEs.

Materials and methods

A cross-sectional study was conducted Jul 2017 ∼ Mar 2021. We assessed the amount of HEs using standard ETDRS photographs for comparison. HEs severity was rated as "no or questionable", "moderate" or "severe". Serum samples were processed via high coverage pseudotargeted lipidomics analysis, and untargeted liquid chromatography coupled with time-of-flight mass spectrometry for metabolomics study, respectively. Weighted gene co-expression network analyses, partial least squares-discriminant analysis, and multi-receiver operating characteristic analysis were applied.

Results

A total of 167 patients were included. Discovery group: 116 eyes (116 patients). Validation group: 51 eyes (51 patients). 888 lipids were detected and divided into 18 modules (MEs), ME1 ∼ ME18. Lipids in ME1 significantly increased in patients with HEs in DR (NPDR and PDR combined), NPDR, and PDR, respectively. ME1 enriched to triglycerides (29%), ceramides (17%), and N-acylethanolamines (15%). A combined model of 20 lipids was the best to discriminate HEs, area under curve = 0.804, 95% confidence interval = 0.674-0.916. For metabolomics analysis, 19 metabolites and 13 pathways associated with HEs were identified. Taurine and hypotaurine metabolism, cysteine and methionine metabolism were closely related to HEs (P < 0.01).

Conclusions

The lipids and metabolites identified may serve as prediction biomarkers in the early stage of HEs in DR.

Correlations of blood lipids with early changes in macular thickness in patients with diabetes

PURPOSE

This study aimed to investigate the correlations of blood lipids with changes in macular volume and thickness in patients with diabetes.

METHODS

Central subfield macular thickness (CSMT) and central subfield macular volume (CSMV) were measured in 85 patients with type 2 diabetes (DM2) using spectral-domain optical coherence tomography (SD-OCT). In addition, serum creatinine (Cr), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC), glycated hemoglobin (HbA1c), and proteinuria were measured in all patients.

RESULTS

The mean CSMT of the 85 patients was 272.8±16.9μm, and CSMV was 215.1±14.6×10^-3mm³. TC, LDLC, HbA1c, and proteinuria were closely correlated to CSMT, and HDLC, HbA1c, and proteinuria were correlated to CSMV. After adjustment for sex, age, DM2 course, proteinuria, and HbA1c, LDLC was significantly correlated to CSMT (95% confidence interval (CI), 1.93-11.05, P=0.008) and CSMV (95% CI, 0.92-8.41, P=0.021); however, HDLC, TC, and TG showed no significant correlation with CSMT or CSMV.

CONCLUSIONS

Increased LDLC was closely correlated to changes in CSMT and CSMV in early diabetic patients, and increased CSMT was also accompanied by increased LDLC; therefore, this type of patient would be more likely to develop macular edema.

Impact of metabolic control on macular thickness in diabetic macular oedema

PURPOSE

To investigate the impact of metabolic control on macular thickness measured using optical coherence tomography in patients with diabetic retinopathy with or without macular oedema.

METHODS

A total of 124 patients with diabetic retinopathy ( n = 70 without macular oedema and n = 54 with macular oedema) were enrolled. Optical coherence tomography parameters measured included central macular thickness and total macular volume. Metabolic factors with correlation to optical coherence tomography parameters were fasting plasma glucose, glycosylated haemoglobin, triglyceride, low-density lipoprotein and estimated glomerular filtration rate. Multiple linear regression models were used to evaluate associations between optical coherence tomography parameters and metabolic factors.

RESULTS

Higher glycosylated haemoglobin values were correlated with increased central macular thickness in patients without macular oedema ( R = 0.289, p = 0.015), whereas glycosylated haemoglobin values were inversely associated with central macular thickness in patients with macular oedema ( R = -0.374, p = 0.005). Both were found to be statistically significant after adjusting for age, sex and diabetic retinopathy severity in addition to other metabolic factors ( p = 0.009 and p = 0.002, respectively).

CONCLUSION

Strict metabolic control may not be associated with better macular thickness in diabetic patients with co-existing macular oedema.

Risk factors for diabetic macular oedema in type 2 diabetes: A case-control study in a United Kingdom primary care setting

AIM

To identify risk factors associated with the development of DMO among patients diagnosed with type 2 diabetes managed in a primary care setting in the UK.

METHODS

A case-control study nested in a cohort of incident Type 2 diabetes identified in The Health Improvement Network database from 2000-2007. Cases were people with DMO (N=211) and controls were a DMO-free sample (N=2194). No age restrictions were applied. Adjusted odds ratios and 95%CIs were estimated (OR; 95%CI).

RESULTS

DMO increased with high alcohol use (2.88; 1.49-5.55), cataracts (4.10; 2.73-6.15), HbA1c ≥7% (1.58; 1.08-2.32), systolic blood pressure ≥160mm Hg (2.03; 1.17-3.53), total cholesterol ≥5mmol/L (1.66; 1.15-2.39), LDL ≥3mmol/L (1.73; 1.14-2.61), and microalbuminuria (1.78; 1.16-2.73). Diuretic drugs were associated with a reduced risk of DMO (0.68; 0.47-0.99), as did smoking (0.47; 0.28-0.77), overweight (0.53; 0.30-0.96) or obesity (0.52; 0.30-0.91) at diabetes diagnosis, and high triglyceride levels (0.51; 0.35-0.74). Patients treated with anti-diabetic drugs showed higher risk of DMO than non-treated patients, particularly those with sulphonylureas (3.40; 2.42-4.78), insulin (3.21; 1.92-5.36) or glitazones (1.88; 1.17-3.04).

CONCLUSION

In patients with type 2 diabetes managed in primary care, multiple factors associated with DMO were identified, such as cataracts, microalbuminuria and high levels of HbA1c, systolic BP, total cholesterol, and LDL. Diuretic drugs were associated with a reduced risk of DMO. Treated diabetes, particularly with sulphonylureas, insulin or glitazones showed highest risk of DMO. The inverse association between smoking, obesity, and triglycerides and DMO deserves further research.

Risk factors for diabetic retinopathy in people with Type 2 diabetes: A case-control study in a UK primary care setting

AIM

To identify risk factors of diabetic retinopathy (DR) among people with Type 2 diabetes mellitus in UK primary care.

METHODS

A case-control study nested in a cohort of incident Type 2 diabetes identified in The Health Improvement Network database from 2000 to 2007. Cases were people with DR (N=7735) and controls were a DR-free sample (N=9395). No age restrictions were applied. Adjusted odds ratios and 95% CIs were estimated.

RESULTS

21% of DR cases were identified during the first semester after Type 2 diabetes diagnosis. After controlling for delay on the Type 2 diabetes diagnosis, the DR risk increased with the duration of diabetes. DR increased with a mean systolic BP ≥150mmHg (1.18; 1.10-1.27), high alcohol consumption (1.34; 1.11-1.61), glycated haemoglobin (≥75 to <86: 1.14; 1.00-1.31; ≥86 to <97mmol/mol: 1.25; 1.07-1.45; ≥97mmol/mol: 1.21; 1.07-1.37), microalbuminuria (1.16; 1.06-1.27), and retinal vein occlusion (2.47; 1.67-3.66). Glaucoma and retinal arterial occlusion showed an OR of 0.71 (0.60-0.84) and 0.63 (0.40-1.01), respectively. HDL ≥1.55mmol/l (0.88; 0.80-0.98), high triglycerides (2.3-5.6mmol/l: 0.90; 0.82-0.99; >5.6mmol/l: 0.85; 0.64-1.13) or smoking (0.89; 0.81-0.97) had a slightly reduced DR risk. Users of hypoglycaemic agents had an increased DR risk.

CONCLUSION

Some DR cases were identified near the diabetes diagnosis date suggesting that a delayed diabetes diagnosis is still common. Glaucoma, retinal arterial occlusion and high HDL levels were inversely associated with DR, while retinal vein occlusion, alcohol and other well-known risk factors were positively associated.

Role of Lipids in Retinal Vascular and Macular Disorders

Retinal diseases are significant by increasing problem in every part of the world. While excellent treatment has emerged for various retinal diseases, treatment for early disease is lacking due to an incomplete understanding of all molecular events. With aging, there is a striking accumulation of neutral lipids in Bruch's membrane. These neutral lipids leads to the creation of a lipid wall at the same locations where drusen and basal linear deposit, pathognomonic lesions of Age-related macular degeneration, subsequently form. High lipid levels are also known to cause endothelial dysfunction, an important factor in the pathogenesis of Diabetic Retinopathy. Various studies suggest that 20 % of Retinal Vascular Occlusion is connected to hyperlipidemia. Biochemical studies have implicated mutation in gene encoding ABCA4, a lipid transporter in pathogenesis of Stargardt disease. This article reviews how systemic and local production of lipids might contribute to the pathogenesis of above retinal disorders.

Retinal Sensitivity over Hard Exudates in Diabetic Retinopathy

PURPOSE

To evaluate retinal sensitivity over hard exudates in correlation with the spectral domain optical coherence tomography (SD-OCT) findings in eyes with diabetic retinopathy.

METHODS

Twelve eyes of 10 patients with hard exudates associated with diabetic retinopathy were enrolled in this study. All subjects underwent a complete ophthalmic examination including SD-OCT (Copernicus, Zawiercie, Poland) and microperimetry (MP1; Nidek Technologies, Padova, Italy). Retinal sensitivity was measured, over the areas with hard exudates and compared to corresponding locations devoid of hard exudates, using a semi-automatic program. The size of the hard exudate plaque was measured using the measurement software in the microperimeter. Retinal thickness in the area of the hard exudates and foveal thickness were measured using SD-OCT.

RESULTS

Mean retinal sensitivity over hard exudates was 4.97 ± 4.17 dB which was significantly (P = 0.0001) reduced as compared to locations devoid of hard exudates. No significant correlation (r=-0.23, P = 0.45) was found between the size of the hard exudates and retinal sensitivity. A significant negative correlation was found between retinal sensitivity and retinal thickness at the area of the hard exudates (r=-0.65, P = 0.05), and between retinal sensitivity and foveal thickness (r=-0.91, P = 0.001).

CONCLUSION

In eyes with diabetic retinopathy, retinal sensitivity was reduced due to the presence of hard exudates in the outer retinal layers and retinal thickening but this was not correlated with the size of the hard exudates.

The impact of metabolic parameters on clinical response to VEGF inhibitors for diabetic macular edema

AIMS

Evaluate the role of systemic factors on the functional and anatomic outcomes of anti-VEGF therapy for diabetic macular edema (DME).

METHODS

A retrospective consecutive case series of 124 patients with DME treated with anti-VEGF therapy was collected. The main outcome measures were change in best corrected visual acuity (BCVA) and change central subfield macular thickness (CST) measured with spectral-domain ocular tomography coherence (SD-OCT); and their correlation with clinical findings.

RESULTS

Patients with serum hemoglobin A1c values (HbA1c) ≤ 7.0% had a statistically significant improvement in BCVA (20/66 to 20/43, p < 0.001), and those patients with HBA1c > 7.0% also had a significant but less robust improvement in BCVA (20/78 to 20/62, p = 0.024). CST improved significantly in both groups, but showed a larger magnitude of improvement in the group with better DM control [-140.7 microns (p < 0.001) and -83.3 microns (p < 0.001)]. Mean HBA1c levels remained relatively stable during the follow-up in both groups, but patients with improved glucose control during the study duration had a significantly lower retinal thickness than patients that had a stable or worsening HbA1c (mean final CST of 324.3 versus 390.0 μm, respectively, p = 0.042). Other systemic parameters were not correlated with changes in OCT thickness or BCVA. There was not a significant difference related to number of intravitreal injection in the HbA1c ≤ 7.0% group compared to HbA1c > 7.0% group, mean of 5.48 and 6.0 intravitreal injections respectively (p = 0.362).

CONCLUSION

This study suggests that glucose regulation can impact the response to anti-VEGF therapy in the management of DME.

Association of serum lipid levels with diabetic retinopathy

AIM

To assess the association between serum lipids and diabetic retinopathy (DR).

METHODS

Sixty-one diabetic patients without retinopathy(NDR), 55 diabetic patients with non-proliferative retinopathy(NPDR) and 75 diabetic patients with proliferative retinopathy (PDR) according to ETDRS grading scale were enrolled in this study. Total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), very low density lipoprotein (VLDL) and triglyceride values were compared between the groups.

RESULTS

The groups were well-balanced in terms of age and gender (P=0.071, P=0.265 respectively). The mean HbA1c values were significantly lower in NDR group than the NPDR and PDR groups (P=0.004, P=0.009 respectively). Mean total cholesterol, triglyceride, LDL, HDL and VLDL levels were not significantly different between the groups (P=0.693, P=0.774, P=0.644, P=0.910 and P=0.967 respectively, one way ANOVA). Mean total cholesterol, triglyceride, LDL, HDL and VLDL levels were not significantly different between the patients with ME and patients without ME (P=0.622, P=0.113, P=0.955, P=0.735 and P=0.490 respectively, t-test). The mean blood glucose significantly correlated with total cholesterol (r=0.173, P=0.017) and LDL (r=0.190, P=0.008). The mean HbA1c significantly correlated with total cholesterol (r=0.158, P=0.030) and triglyceride (r=0.148, P=0.042).

CONCLUSION

Serum lipid levels were not significantly associated with the severity of DR or existence of ME despite the significant correlation between the mean blood glucose, HbA1c and total cholesterol.

Risk factors for clinically significant macular edema in a multi-ethnics population with type 2 diabetes

AIM

To determine the risk factors of clinically significant macular edema (CSME) in patients with non-proliferative diabetic retinopathy (NPDR) in a multi-ethnics Malaysian population.

METHODS

We performed a case control study in which 150 patients with bilateral NPDR and CSME in either eye were compared to 150 patients with bilateral NPDR and no CSME in both eyes. CSME and NPDR were graded according to Early Treatment of Diabetic Retinopathy Study criteria. Student's t-test, odds ratio and multiple logistic regression analysis were performed to analyze the duration of diabetes, body mass index (BMI), blood pressure(BP), total cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL), triglycerides (TG), fasting blood glucose (FBG), HbA1c, full blood count, serum creatinine and proteinuria between the two groups.

RESULTS

Both groups were matched in terms of age, gender and ethnicity. Duration of diabetes, total serum cholesterol, serum LDL, FBG, HbA1c and serum creatinine were significantly higher in the CSME group (P<0.05). The hemoglobin, packed cell volume were significantly lower in the CSME group (p<0.05). There was no significant difference for serum HDL, TG, BMI, systolic and diastolic BP. Multiple logistic regression analysis showed that total serum cholesterol and HbA1c had significantly high odds of developing CSME.

CONCLUSION

HbA1c and total cholesterol are the two most important risk factors associated with CSME in patients with NPDR.

Prevalence and risk factors for diabetic maculopathy, and its relationship to diabetic retinopathy in elderly Japanese patients with type 2 diabetes mellitus

AIMS

To determine the prevalence of diabetic retinopathy and diabetic maculopathy in Japanese patients older than 65 years-of-age with type 2 diabetes mellitus. In addition, to determine the relationship between the severity of retinopathy and maculopathy, and the risk factors for these conditions in Japanese patients with the same characteristics.

METHODS

This was a cross-sectional study carried out at the enrolment of patients who participated in a randomized controlled trial. A total of 960 eyes of 960 Japanese patients with type 2 diabetes who were ≥ 65 years-of-age were analyzed.

RESULTS

Our data showed that there was a correlation between the severity of retinopathy and the severity of maculopathy. The risk factors for the severity of retinopathy were different from the risk factors for the severity of maculopathy. The age, duration of diabetes, systemic pulse pressure, fasting insulin, insulin treatment of diabetes, high-density lipoprotein cholesterol, microalbumin-to-creatinine ratio and history of cerebrovascular disease all contributed significantly to the severity of retinopathy. The duration of diabetes, insulin treatment and microalbumin-to-creatinine ratio were correlated with the severity of maculopathy.

CONCLUSIONS

The risk factors related to diabetic retinopathy and maculopathy in Japanese patients with type 2 diabetes mellitus aged ≥ 65 years were different from that in other countries. Our data also showed that the certain risk factors for retinopathy differ from those associated with maculopathy.