The relationship of dietary fish intake to diabetic retinopathy and retinal vascular caliber in patients with type 2 diabetes

Inter-Relations between Dietary Patterns and Glycemic Control-Related Biomarkers on Risk of Retinopathy in Type 2 Diabetes

Diabetic retinopathy (DR), which can cause vision loss, may progress faster with poor glycemic control and oxidative stress. This study aims to examine how dietary patterns and glycemic control biomarkers relate to retinopathy risk in type 2 diabetes patients. In this study, we enrolled diabetic patients with retinopathy (DR) (n = 136) and without retinopathy (no DR) (n = 466) from a cohort of participants in the "Blood Pressure Control to Reduce the Risk of Type 2 Diabetic Nephropathy Study". Hemoglobin A1c (HbA1c) and malondialdehyde were defined as elevated when their levels reached ≥8.5% and ≥2/3 (16.2 μm), respectively. Dietary data were collected by a food frequency questionnaire. Dietary patterns were identified by factor analysis. Elevated HbA1c was significantly correlated with increased risk of DR (OR: 2.12, 95% CI: 1.14-3.93, p = 0.017). In subjects with a high animal protein and processed food dietary pattern (≥highest tertile score) or a low vegetable intake pattern ( Collapse

Key Words

• diabetic retinopathy
• glycated hemoglobin A1c
• malondialdehyde

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MESH Headings

• Humans
• Diabetes Mellitus, Type 2/blood
• Diabetes Mellitus, Type 2/complications
• Male
• Diabetic Retinopathy/etiology
• Diabetic Retinopathy/epidemiology
• Diabetic Retinopathy/blood
• Female
• Middle Aged
• Biomarkers/blood
• Glycated Hemoglobin/analysis
• Glycated Hemoglobin/metabolism
• Diet/adverse effects
• Risk Factors
• Aged
• Glycemic Control
• Malondialdehyde/blood
• Blood Glucose/metabolism
• Feeding Behavior
• Dietary Patterns

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Grants

• 112-2320-B-037-018 National Science and Technology Council, Taiwan
• KMUH-108-8R78 Kaohsiung Medical University Hospital

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Affiliation(s)

Yu-Ju Wu Department of Nutrition and Dietetics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; Graduate Institute of Medicine and Department of Public Health and Environmental Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807378, Taiwan;
Chih-Cheng Hsu Institute of Population Health Sciences, National Health Research Institutes, Miaoli County 350401, Taiwan; (C.-C.H.); (Y.-F.H.) Department of Health Services Administration, China Medical University, Taichung 4064040, Taiwan Department of Family Medicine, Min-Sheng General Hospital, Taoyuan 330056, Taiwan National Center for Geriatrics and Welfare Research, National Health Research Institutes, Yunlin 632007, Taiwan
Shang-Jyh Hwang Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; Division of Endocrinology and Metabolism, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807378, Taiwan;
Kun-Der Lin The Lin’s Clinics, Kaohsiung 807057, Taiwan;
Pi-Chen Lin Division of Endocrinology and Metabolism, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807378, Taiwan;
Ya-Fang Huang Institute of Population Health Sciences, National Health Research Institutes, Miaoli County 350401, Taiwan; (C.-C.H.); (Y.-F.H.)
Chien-Hung Lee Department of Public Health, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 807378, Taiwan;
Chiao-I Chang Graduate Institute of Medicine and Department of Public Health and Environmental Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807378, Taiwan;
Meng-Chuan Huang Department of Nutrition and Dietetics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807378, Taiwan; Graduate Institute of Medicine and Department of Public Health and Environmental Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807378, Taiwan;

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Effect of High-Sucrose Diet on the Occurrence and Progression of Diabetic Retinopathy and Dietary Modification Strategies

As the most serious of the many worse new pathological changes caused by diabetes, there are many risk factors for the occurrence and development of diabetic retinopathy (DR). They mainly include hyperglycemia, hypertension, hyperlipidemia and so on. Among them, hyperglycemia is the most critical cause, and plays a vital role in the pathological changes of DR. High-sucrose diets (HSDs) lead to elevated blood glucose levels in vivo, which, through oxidative stress, inflammation, the production of advanced glycation end products (AGEs) and vascular endothelial growth factor (VEGF), cause plenty of pathological damages to the retina and ultimately bring about loss of vision. The existing therapies for DR primarily target the terminal stage of the disease, when irreversible visual impairment has appeared. Therefore, early prevention is particularly critical. The early prevention of DR-related vision loss requires adjustments to dietary habits, mainly by reducing sugar intake. This article primarily discusses the risk factors, pathophysiological processes and molecular mechanisms associated with the development of DR caused by HSDs. It aims to raise awareness of the crucial role of diet in the occurrence and progression of DR, promote timely changes in dietary habits, prevent vision loss and improve the quality of life. The aim is to make people aware of the importance of diet in the occurrence and progression of DR. According to the dietary modification strategies that we give, patients can change their poor eating habits in a timely manner to avoid theoretically avoidable retinopathy and obtain an excellent prognosis.

Comprehensive retinal vascular measurements: time in range is associated with peripheral retinal venular calibers in type 2 diabetes in China

AIM

Retinal vascular parameters are biomarkers of diabetic microangiopathy. We aimed to investigate the relationship between time in range (TIR) assessed by continuous glucose monitoring (CGM) and retinal vascular parameters in patients with type 2 diabetes in China.

METHODS

The TIR assessed by CGM and retinal photographs were obtained at the same time from adults with type 2 diabetes who were recruited. Retinal vascular parameters were extracted from retinal photographs by a validated fully automated computer program, and TIR was defined as between 3.9-7.8 mmol/L over a 24-h period. The association between TIR and caliber of retinal vessels distributed in different zones were analyzed using multivariable linear regression analyses.

RESULTS

For retinal vascular parameters measurements, the peripheral arteriovenous and middle venular calibers widen with decreasing TIR quartiles (P < 0.05). Lower TIR was associated with wider peripheral venule after adjusting for potential confounders. Even after further correction for GV, there was still a significant correlation between TIR and peripheral vascular calibers (CV: β = - 0.015 [- 0.027, - 0.003], P = 0.013; MAGE: β = - 0.013 [- 0.025, - 0.001], P = 0.038) and SD: β = - 0.013 [- 0.026, - 0.001], P = 0.004). Similar findings were not found for the middle and central venular calibers or arterial calibers located in different zones.

CONCLUSIONS

The TIR was associated with adverse changes to peripheral retinal venules but not central and middle vessels in patients with type 2 diabetes, suggesting that peripheral retinal vascular calibers may be affected by glycemic fluctuations earlier.

Dietary Intake and Diabetic Retinopathy: A Systematic Review of the Literature

Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus. The evidence connecting dietary intake and DR is emerging, but uncertain. We conducted a systematic review to comprehensively summarize the current understanding of the associations between dietary consumption, DR and diabetic macular edema (DME). We systematically searched PubMed, Embase, Medline, and the Cochrane Central Register of Controlled Trials between January 1967 to May 2022 for all studies investigating the effect of diet on DR and DME. Of the 4962 articles initially identified, 54 relevant articles were retained. Our review found that higher intakes of fruits, vegetables, dietary fibers, fish, a Mediterranean diet, oleic acid, and tea were found to have a protective effect against DR. Conversely, high intakes of diet soda, caloric intake, rice, and choline were associated with a higher risk of DR. No association was seen between vitamin C, riboflavin, vitamin D, and milk and DR. Only one study in our review assessed dietary intake and DME and found a risk of high sodium intake for DME progression. Therefore, the general recommendation for nutritional counseling to manage diabetes may be beneficial to prevent DR risk, but prospective studies in diverse diabetic populations are needed to confirm our findings and expand clinical guidelines for DR management.

Enhancement of nutritional value of fried fish using an artificial intelligence approach

Frying affects the nutritional quality of fish detrimentally. In this study, using Catla catla and mustard oil, experiments were carried out in varying temperatures (140-240 °C), times (5-20 min), and oil amounts (25-100 ml/kg of fish) which established drastic reduction of 44.97% and 99.40% for polyunsaturated fatty acid (PUFA)/saturated fatty acids (SFA) and index of atherogenicity (IA) profile, respectively. Artificial neural network (ANN) was implemented successfully to provide an association between the independent inputs with dependent outputs (values of R² were 0.99 and 0.98; RMSE were 0.038 and 0.046; and performance were 0.038 and 0.067 for PUFA/SFA and IA, respectively) by exhaustive search of various algorithms and activation functions available in literature. ANN model-based meta-heuristic, stochastic optimization formalisms, genetic algorithm (GA) and particle swarm optimization (PSO), were applied to optimize the combination of cooking parameters for improving the nutritional quality of food which improved the nutritional value by maximizing the PUFA/SFA profile up to 63.05% and minimizing the IA profile to 99.64%. Multi-objective genetic algorithm (MOGA) was also employed to tune the inputs by maintaining a balance between the contrasting outputs and enhance the overall food value simultaneously with multi-objective (beneficial for health, economic, and environment-friendly) proposal. MOGA was able to improve the PUFA/SFA profile up to 44.76% and reduce the IA profile to 92.94% concurrently with the reduction of wastage of culinary media and energy consumption, following the optimized cooking condition (118.92 °C, 6.06 min, 40 ml oil/kg of fish).

Serum and Macular Carotenoids in Relation to Retinal Vessel Caliber Fifteen Years Later, in the Second Carotenoids in Age-Related Eye Disease Study

Purpose

We investigated whether dietary carotenoids lutein and zeaxanthin (L/Z) in the serum and macula were associated with central retinal arteriole and venule calibers in a follow-up ancillary study among older women in the Women's Health Initiative.

Methods

Among 390 women who participated in Carotenoids in Age-Related Eye Disease Study 2 (CAREDS2) (2016–2019), we investigated associations between serum L/Z at Women's Health Initiative baseline (1994–1998), and macular pigment optical density (MPOD) at CAREDS baseline (2001–2004), with central retinal vessel caliber in CAREDS2. MPOD was measured using heterochromatic flicker photometry (0.5° from the foveal center) in CAREDS baseline and CAREDS2. Vessel calibers were measured from fundus photographs (CAREDS2). We also explored associations in women with stable MPOD (±0.10 optical density units) over 15 years (n = 106), given the long-term increases in MPOD related to diet patterns and supplement use. Associations were investigated using linear modeling.

Results

In the full sample (n = 390), higher serum L/Z (tertile 3 vs. 1) was positively associated with arteriole caliber (mean ± SE, 145.0 ± 1.4 µm vs. 140.8 ± 1.4 µm; P = 0.05) and venule caliber (214.6 ± 2.2 µm vs. 207.5 ± 2.2 µm; P = 0.03). MPOD was also associated with wider vessel calibers (tertile 3 vs. 1), but the trend was only statistically significant for venules (144.4 ± 1.4 µm vs. 141.1 ± 1.4 µm [P = 0.12] and 213.3 ± 2.1 µm vs. 206.0 ± 2.1 µm [P = 0.02], respectively.) Most associations were strengthened in women with stable MPOD over 15 years, including between MPOD and arteriole caliber (149.8 ± 2.6 µm vs.135.8 ± 3.0 µm; P = 0.001).

Conclusions

Higher L/Z status in serum and retina was associated with larger central retinal vessel calibers. Prospective studies and clinical trials are needed to elucidate whether L/Z supplementation prevents vision loss through increasing blood flow.

The potential of marine resources for retinal diseases: a systematic review of the molecular mechanisms

We rely on vision more than on any other sense to obtain information about our environment. Hence, the loss or even impairment of vision profoundly affects our quality of life. Diet or food components have already demonstrated beneficial effects on the development of retinal diseases. Recently, there has been a growing interest in resources from marine animals and plants for the prevention of retinal diseases through nutrition. Especially fish intake and omega-3 fatty acids have already led to promising results, including associations with a reduced incidence of retinal diseases. However, the underlying molecular mechanisms are insufficiently explained. The aim of this review was to summarize the known mechanistic effects of marine resources on the pathophysiological processes in retinal diseases. We performed a systematic literature review following the PRISMA guidelines and identified 107 studies investigating marine resources in the context of retinal diseases. Of these, 46 studies described the underlying mechanisms including anti-inflammatory, antioxidant, antiangiogenic/vasoprotective, cytoprotective, metabolic, and retinal function effects, which we critically summarize. We further discuss perspectives on the use of marine resources for human nutrition to prevent retinal diseases with a particular focus on regulatory aspects, health claims, safety, and bioavailability.

Protective Effects and Molecular Signaling of n-3 Fatty Acids on Oxidative Stress and Inflammation in Retinal Diseases

Oxidative stress and inflammation play crucial roles in the development and progression of retinal diseases. Retinal damage by various etiologies can result in retinopathy of prematurity (ROP), diabetic retinopathy (DR), and age-related macular degeneration (AMD). n-3 fatty acids are essential fatty acids and are necessary for homeostasis. They are important retinal membrane components and are involved in energy storage. n-3 fatty acids also have antioxidant and anti-inflammatory properties, and their suppressive effects against ROP, DR, and AMD have been previously evaluated. α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and their metabolites have been shown to alleviate retinal oxidative stress and inflammation involving various biological signaling pathways. In this review, we summarize the current understanding of the n-3 fatty acids effects on the mechanisms of these retinal diseases and how they exert their therapeutic effects, focusing on ALA, EPA, DHA, and their metabolites. This knowledge may provide new remedial strategies for n-3 fatty acids in the prevention and treatment of retinal diseases associated with oxidative stress and inflammation.

Optical Coherence Tomography Angiography in Diabetes and Diabetic Retinopathy

Diabetic retinopathy (DR) is a common complication of diabetes mellitus that disrupts the retinal microvasculature and is a leading cause of vision loss globally. Recently, optical coherence tomography angiography (OCTA) has been developed to image the retinal microvasculature, by generating 3-dimensional images based on the motion contrast of circulating blood cells. OCTA offers numerous benefits over traditional fluorescein angiography in visualizing the retinal vasculature in that it is non-invasive and safer; while its depth-resolved ability makes it possible to visualize the finer capillaries of the retinal capillary plexuses and choriocapillaris. High-quality OCTA images have also enabled the visualization of features associated with DR, including microaneurysms and neovascularization and the quantification of alterations in retinal capillary and choriocapillaris, thereby suggesting a promising role for OCTA as an objective technology for accurate DR classification. Of interest is the potential of OCTA to examine the effect of DR on individual retinal layers, and to detect DR even before it is clinically detectable on fundus examination. We will focus the review on the clinical applicability of OCTA derived quantitative metrics that appear to be clinically relevant to the diagnosis, classification, and management of patients with diabetes or DR. Future studies with longitudinal design of multiethnic multicenter populations, as well as the inclusion of pertinent systemic information that may affect vascular changes, will improve our understanding on the benefit of OCTA biomarkers in the detection and progression of DR.

Does daily dietary intake affect diabetic retinopathy progression? 10-year results from the 45 and Up Study

Background/aims

To evaluate the associations of dietary consumption with the 10-year incidence of diabetic retinopathy (DR) progression in working-aged Australians with diabetes.

Methods

We obtained longitudinal data of all diabetic subjects aged 45–65 years from the baseline of the 45 and Up Study and linked this data with Medicare Benefits Schedule (MBS) and Pharmaceutical Benefits Scheme claims until 2016. Retinal photocoagulation (RPC), as determined based on the MBS data, was used as a proxy measure of DR progression. Dietary measurements were assessed via self-reported consumption of meat, dairy products, whole-meal bread, breakfast cereal, vegetables, fruit and fruit juice using a self-administered questionnaire at baseline. Cox regression was used to assess the association between dietary consumption and incident RPC during the follow-up period.

Results

A total of 8122 participants were included in the current analysis with a mean age of 57.2±5.2 years. During a mean follow-up of 8.6 years, 314 participants (3.8% of baseline) received RPC. Higher consumption of cheese and whole-meal bread was associated with a lower risk of incident RPC, with the HRs of the highest quartiles versus the lowest being 0.58 (95% CI 0.41 to 0.83; test for trend, p=0.007) and 0.64 (0.46 to 0.89; p=0.04), respectively. Body mass index, insulin treatment and gender were significant modifiers for the association between cheese/whole-meal bread and RPC.

Conclusion

Consumption of cheese and whole-meal bread could reduce the risk of DR progression among the working-aged Australian population with diabetes.