Adherence to a Mediterranean diet is associated with a lower risk of diabetic kidney disease among individuals with hyperglycemia: a prospective cohort study.

BACKGROUND: Type 2 diabetes is associated with a variety of complications, including micro- and macrovascular complications, neurological manifestations and poor wound healing. Adhering to a Mediterranean Diet (MED) is generally considered an effective intervention in individuals at risk for type 2 diabetes mellitus (T2DM). However, little is known about its effect with respect to the different specific manifestations of T2DM. This prompted us to explore the effect of MED on the three most significant microvascular complications of T2DM: diabetic retinopathy (DR), diabetic kidney disease (DKD), and vascular diabetic neuropathies (DN). METHODS: We examined the association between the MED and the incidence of these microvascular complications in a prospective cohort of 33,441 participants with hyperglycemia free of microvascular complications at baseline, identified in the UK Biobank. For each individual, we calculated the Alternate Mediterranean Diet (AMED) score, which yields a semi-continuous measure of the extent to which an individual's diet can be considered as MED. We used Cox proportional hazard models to analyze hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for demographics, lifestyle factors, medical histories and cardiovascular risk factors. RESULTS: Over a median of 12.3 years of follow-up, 3,392 cases of microvascular complications occurred, including 1,084 cases of diabetic retinopathy (DR), 2,184 cases of diabetic kidney disease (DKD), and 632 cases of diabetic neuropathies (DN), with some patients having 2 or 3 microvascular complications simultaneously. After adjusting for confounders, we observed that higher AMED scores offer protection against DKD among participants with hyperglycemia (comparing the highest AMED scores to the lowest yielded an HR of 0.79 [95% CIs: 0.67, 0.94]). Additionally, the protective effect of AMED against DKD was more evident in the hyperglycemic participants with T2DM (HR, 0.64; 95% CI: 0.50, 0.83). No such effect, however, was seen for DR or DN. CONCLUSIONS: In this prospective cohort study, we have demonstrated that higher adherence to a MED is associated with a reduced risk of DKD among individuals with hyperglycemia. Our study emphasizes the necessity for continued research focusing on the benefits of the MED. Such efforts including the ongoing clinical trial will offer further insights into the role of MED in the clinical management of DKD.

Effects of a Mediterranean diet on the development of diabetic complications: A longitudinal study from the nationwide diabetes report of the National Program for Prevention and Control of Diabetes (NPPCD 2016-2020).

OBJECTIVE: To evaluate the effectiveness of a Mediterranean dietary pattern on the incidence of macrovascular and microvascular complications of diabetes, namely cardiovascular disease (CVD), diabetic foot disorders, diabetic retinopathy, nephropathy, and neuropathy. METHODS: This longitudinal study was conducted among 71392 adults with diabetes who attended academic tertiary-care outpatient clinics from February 2016 to March 2020 across Iran using the National Program for Prevention and Control of Diabetes database. Among them, 22187 patients with diabetes (type 1 and type 2) completed 2-11 follow-up visits after baseline registration. The association between adherence to a Mediterranean diet and diabetic complications was assessed using pooled logistic regression models. This association was adjusted for potential confounders. The effect of time was assessed using fractional polynomials. RESULTS: A total of 22187 participants were included in the analysis (30.22% men and 69.78% women) with either type 1 (mean age 50.7 years) or type 2 (mean age 59.9 years) diabetes. After adjustment for confounding variables, there was a negative correlation between adherence to a Mediterranean diet and the incidence of CVD among patients with type 1 diabetes (T1D) and 2 diabetes (T2D) (OR= 0.53, 95% CI: 0.37 - 0.75, p-value <0.001 and OR= 0.61, 95% CI: 0.57 - 0.89, p-value <0.001, respectively). Also, the diet had a statistically significant protective effect against incident symptomatic neuropathy (OR= 0.32, 95% CI: 0.23 - 0.43, p-value <0.001, and OR= 0.68, 95% CI: 0.64 - 0.72, p-value <0.001, respectively), nephropathy (OR= 0.42, 95% CI: 0.30 - 0.58, p-value <0.001, and OR= 0.88, 95% CI: 0.80 - 0.96, p-value= 0.007, respectively), and retinopathy (OR= 0.32, 95% CI: 0.24 - 0.44, p-value <0.001, and OR= 0.68, 95% CI: 0.61 - 0.71, p-value <0.001, respectively) in T1D and T2D. CONCLUSION: The Mediterranean dietary pattern is associated with a lower incidence of CVD and microvascular complications (i.e. diabetic retinopathy, nephropathy, and neuropathy) among a cohort of patients with T1D and T2D in Iran.

A Systematic Review of Carotenoids in the Management of Diabetic Retinopathy.

Diabetic retinopathy, which was primarily regarded as a microvascular disease, is the leading cause of irreversible blindness worldwide. With obesity at epidemic proportions, diabetes-related ocular problems are exponentially increasing in the developed world. Oxidative stress due to hyperglycemic states and its associated inflammation is one of the pathological mechanisms which leads to depletion of endogenous antioxidants in retina in a diabetic patient. This contributes to a cascade of events that finally leads to retinal neurodegeneration and irreversible vision loss. The xanthophylls lutein and zeaxanthin are known to promote retinal health, improve visual function in retinal diseases such as age-related macular degeneration that has oxidative damage central in its etiopathogenesis. Thus, it can be hypothesized that dietary supplements with xanthophylls that are potent antioxidants may regenerate the compromised antioxidant capacity as a consequence of the diabetic state, therefore ultimately promoting retinal health and visual improvement. We performed a comprehensive literature review of the National Library of Medicine and Web of Science databases, resulting in 341 publications meeting search criteria, of which, 18 were found eligible for inclusion in this review. Lutein and zeaxanthin demonstrated significant protection against capillary cell degeneration and hyperglycemia-induced changes in retinal vasculature. Observational studies indicate that depletion of xanthophyll carotenoids in the macula may represent a novel feature of DR, specifically in patients with type 2 or poorly managed type 1 diabetes. Meanwhile, early interventional trials with dietary carotenoid supplementation show promise in improving their levels in serum and macular pigments concomitant with benefits in visual performance. These findings provide a strong molecular basis and a line of evidence that suggests carotenoid vitamin therapy may offer enhanced neuroprotective effects with therapeutic potential to function as an adjunct nutraceutical strategy for management of diabetic retinopathy.

Mfsd2a overexpression alleviates vascular dysfunction in diabetic retinopathy.

Diabetic retinopathy (DR) is one of the common complications in diabetic patients. Nowadays, VEGF pathway is subject to extensive research. However, about 27% of the patients have a poor visual outcome, with 50% still having edema after two years' treatment of diabetic macular edema (DME) with ranibizumab. Docosahexaenoic acid (DHA), the primary ω-3 long-chain polyunsaturated fatty acid (LC-PUFA), reduces abnormal neovascularization and alleviates neovascular eye diseases. A study reported that fish oil reduced the incidence of retinopathy of prematurity (ROP) by about 27.5% in preterm infants. Although ω-3 LC-PUFAs protects against pathological retinal neovascularization, the treatment effectiveness is low. It is interesting to investigate why DHA therapy fails in some patients. In human vitreous humor samples, we found that the ratio of DHA and DHA-derived metabolites to total fatty acids was higher in vitreous humor from DR patients than that from macular hole patients; however, the ratio of DHA metabolites to DHA and DHA-derived metabolites was lower in the diabetic vitreous humor. The expression of Mfsd2a, the LPC-DHA transporter, was reduced in the oxygen-induced retinopathy (OIR) model and streptozotocin (STZ) model. In vitro, Mfsd2a overexpression inhibited endothelial cell proliferation, migration and vesicular transcytosis. Moreover, Mfsd2a overexpression in combination with the DHA diet obviously reduced abnormal retinal neovascularization and vascular leakage, which is more effective than Mfsd2a overexpression alone. These results suggest that DHA therapy failure in some DR patients is linked to low expression of Mfsd2a, and the combination of Mfsd2a overexpression and DHA therapy may be an effective treatment.

Role of dietary modifications in the management of type 2 diabetic complications.

Diabetes is a chronic metabolic disorder with a high rate of morbidity and mortality. Insufficient insulin secretion and insulin action are two major causes for the development of diabetes, which is characterized by a persistent increase in blood glucose level. Diet and sedentary life style play pivotal role in development of vascular complications in type 2 diabetes. Dietary modification is associated with a reprogramming of nutrient intake, which are proven to be effective for the management of diabetes and associated complications. Dietary modifications modulate various molecular key players linked with the functions of nutrient signalling, regulation of autophagy, and energy metabolism. It activates silent mating type information regulation 2 homolog1 (SIRT1) and AMP-activated protein kinase (AMPK). AMPK mainly acts as an energy sensor and inhibits autophagy repressor Mammalian target of rapamycin (mTOR) under nutritional deprivation. Under calorie restriction (CR), SIRT1 gets activated directly or indirectly and plays a central role in autophagy via the regulation of protein acetylation. Dietary modification is also effective in controlling inflammation and apoptosis by decreasing the level of pro-inflammatory cytokines like nuclear factor kappa- beta (NF-kß), tissue growth factor-beta (TGF-ß), tissue necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). It also improves glucose homeostasis and insulin secretion through beta cell regeneration. This indicates calorie intake plays a crucial role in the pathogenesis of type 2 diabetes-associated complications. The present review, emphasizes the role of dietary modifications in diabetes and associated complications.

Fructus lycii: A Natural Dietary Supplement for Amelioration of Retinal Diseases.

Fructus lycii (F. lycii) is an exotic "berry-type" fruit of the plant Lycium barbarum that is characterized by a complex mixture of bioactive compounds distinguished by their high antioxidant potential. F. lycii is used in traditional Chinese home cooking and in the Chinese Pharmacopeia as an aid to vision and longevity as well as a remedy for diabetes to balance "yin" and "yang" in the body for about two centuries. Although a myriad of bioactive compounds have been isolated from F. lycii, polysaccharides, carotenoids, flavonoids, and phenolics represent the key functional components of F. lycii. F. lycii has been shown to exhibit a wide range of biological activities in experimental settings including antioxidant, anti-inflammatory, antiapoptotic, and neuroprotective effects. Despite its medicinal role dating back to the eighteenth century in the Far East and robust evidence of beneficial effects on ocular health and retinal diseases originating mainly from studies in animal models, the role of F. lycii in the clinical management of retinal diseases is yet to be established. This article comprehensively reviews the literature germane to F. lycii and retinal diseases with particular emphasis on age-related macular degeneration, diabetic retinopathy, and retinitis pigmentosa, which are commonly seen in clinical practice.

Effect of vitamin B12 supplementation on retinal lesions in diabetic rats.

Purpose: Diabetic retinopathy (DR) is the most common complication of diabetes involving microvasculature and neuronal alterations in the retina. Previously, we reported that vitamin B12 deficiency could be an independent risk factor for DR in humans. However, the effect of vitamin B12 supplementation in experimental DR is unknown. Thus, in this study, we investigated the impact of dietary supplementation of vitamin B12 on retinal changes in diabetic rats. Methods: Diabetes was induced in 2-month-old Sprague-Dawley rats and maintained for 4 months. One group of diabetic rats were fed normal levels of vitamin B12, and one group double the quantity of vitamin B12 (50 µg/kg diet). Vitamin B12 and homocysteine levels in the plasma were analyzed with radioimmunoassay (RIA) and high-performance liquid chromatography (HPLC), respectively. At the end of 4 months of experimentation, the eyeballs were collected. Retinal changes were analyzed with hematoxylin and eosin (H&E) staining, immunoblotting, and immunofluorescence methods. Results: Dietary supplementation of vitamin B12 had no effect on food intake, bodyweight, fasting blood glucose, and plasma homocysteine levels in the diabetic rats. However, vitamin B12 supplementation prevented loss of rhodopsin, and overexpression of VEGF, and completely prevented overexpression of HIF1α, GFAP, and endoplasmic reticulum (ER) stress markers (GRP78, ATF6α, XBP1, CHOP, and caspase 12) in the diabetic rat retina. Further, vitamin B12 ameliorated apoptosis in the retina as shown with terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) and prevented retinal thinning. Conclusions: Vitamin B12 supplementation of diabetic rats appeared to be beneficial by circumventing retinal hypoxia, VEGF overexpression, and ER stress-mediated cell death in the retina. The present study adds another potential therapeutic strategy of vitamin B12 in diabetes.

Adjuvant Therapies in Diabetic Retinopathy as an Early Approach to Delay Its Progression: The Importance of Oxidative Stress and Inflammation.

Diabetes mellitus (DM) is a progressive disease induced by a sustained state of chronic hyperglycemia that can lead to several complications targeting highly metabolic cells. Diabetic retinopathy (DR) is a multifactorial microvascular complication of DM, with high prevalence, which can ultimately lead to visual impairment. The genesis of DR involves a complex variety of pathways such as oxidative stress, inflammation, apoptosis, neurodegeneration, angiogenesis, lipid peroxidation, and endoplasmic reticulum (ER) stress, each possessing potential therapeutic biomarkers. A specific treatment has yet to be developed for early stages of DR since no management is given other than glycemic control until the proliferative stage develops, offering a poor visual prognosis to the patient. In this narrative review article, we evaluate different dietary regimens, such as the Mediterranean diet, Dietary Pattern to Stop Hypertension (DASH) and their functional foods, and low-calorie diets (LCDs). Nutraceuticals have also been assessed in DR on account of their antioxidant, anti-inflammatory, and antiangiogenic properties, which may have an important impact on the physiopathology of DR. These nutraceuticals have shown to lower reactive oxygen species (ROS), important inflammatory factors, cytokines, and endothelial damage biomarkers either as monotherapies or combined therapies or concomitantly with established diabetes management or nonconventional adjuvant drugs like topical nonsteroidal anti-inflammatory drugs (NSAIDs).

Silymarin prevents diabetes-induced hyperpermeability in human retinal endothelial cells / La silimarina previene la hiperpermeabilidad inducida por la diabetes en células endoteliales de retina humana

Introduction: Vascular endothelial growth factor (VEGF) plays an essential role in development of diabetic macular edema (DME). While there is evidence suggesting that silymarin, a flavonoid extracted from Silybum marianum, could be useful for prevention and treatment of diabetic nephropathy, no studies have been conducted in diabetic retinopathy (DR). The aim of this study was to assess the effect of silymarin on disruption of inner blood retinal barrier (BRB), the primary cause of DME. Materials and methods: Human retinal endothelial cells (HRECs) were cultured under standard (5.5mM D-glucose) and diabetogenic conditions (25mM D-glucose and 25mM D-glucose + recombinant vascular endothelial growth factor [rVEGF, 25mg/mL]). To assess cell viability, three concentrations of silymarin were tested (2, 4 and 10μg/mL). The effect of silymarin on HREC disruption was determined using a dextran (70kD) permeability asssay. Results: No differences were found in the viability of HRECs treated with 2 or 4μg/mL of silymarin as compared to untreated cells, but viability significantly decreased after using 10 μg/mL. The concentration of 4 μg/mL was therefore selected. Silymarin (4μg/mL) caused a significant decrease in VEGF-induced permeability in both media with 5.5nM (422±58 vs. 600±72 ng/mL/cm2; p<0.03) and 25nM of D-glucose (354 ± 28 vs. 567 ± 102 ng/mL/cm2; p<0.04). Discussion: Our results show that silymarin is effective for preventing hyperpermeability induced by diabetic conditions in HRECs. Further studies are needed to assess whether silymarin could be useful to treat DME (AU)

Introducción: El Vascular endothelial growth factor (VEGF) juega un papel esencial en el desarrollo del edema macular diabético (EMD). Existe evidencia que indica que el uso de la silimarina, extracto flavonoide del Silybum marianum, podría ser útil en la prevención y el tratamiento de la nefropatía diabética pero no se dispone de datos en retinopatía diabética (RD). El objetivo del estudio es evaluar el efecto de la silimarina sobre la disrupción de la barrera hematorretininana, que es la causa primaria del EMD. Material y métodos: Células endoteliales de retina humana (HRECs) se cultivaron en condiciones estándar (5.5mM de D-glucosa) y en condiciones suprafisiológicas de glucosa (25mM de D-glucosa y 25mM de D-glucosa + VEGF 25mg/dl). Para evaluar la viabilidad de las células se probaron 3 concentraciones de silimarina (2, 4 y 10μg/ml). El efecto de la silimarina sobre la disrupción de las HRECs se determinó mediante análisis de permeabilidad a dextrano (70kD). Resultados: No se observaron diferencias en la viabilidad de las HRECs tratadas con 2 o 4μg/ml de silimarina en comparación con las células no tratadas, pero se observó una reducción de la viabilidad con la concentración de 10μg/ml. Por consiguiente, se seleccionó la concentración de 4μg/ml de silimarina. La silimarina (4μg/ml) produjo un descenso significativo de la permeabilidad inducida por VEGF tanto en medio con 5.5mM de D-glucosa (422 ±58 vs. 600 ±72 ng/ml/cm2; p<0.03) como en medio con 25mM de D-glucosa (354±28 vs. 567±102 ng/ml/cm2; p<0.04). Discusión: Nuestros resultados demuestran que la silimarina es efectiva para prevenir la hiperpermeabilidad inducida por condiciones suprafisiológicas de glucosa en HRECs. Son necesarios más estudios para evaluar si la silimarina podría ser útil para el tratamiento del EMD (AU)

Coconut phytocompounds inhibits polyol pathway enzymes: Implication in prevention of microvascular diabetic complications.

Coconut oil (CO), the primary choice of cooking purposes in the south Asian countries, is rich in medium chain saturated fatty acids, especially lauric acid (50-52%). The oil has high medicinal use in Ayurvedic system and known to contain polyphenolic antioxidants. Studies have reported that CO improves insulin sensitivity and shows hypoglycemic effect. However, there is no information regarding its effect on chronic diabetic complications including retinopathy and nephropathy is available. The secondary diabetic complications are mediated by the activation of polyol pathway, where aldose reductase (AR) plays crucial role. In this study, in silico analysis has been used to screen the effect of CO as well as its constituents, MCFAs and phenolic compounds, for targeting the molecules in polyol pathway. The study revealed that lauric acid (LA) interacts with AR and DPP-IV of polyol pathway and inhibits the activity of these enzymes. Validation studies using animal models confirmed the inhibition of AR and SDH in wistar rats. Further, the LA dose dependently reduced the expression of AR in HCT-15 cells. Together, the study suggests the possible role of CO, particularly LA in reducing secondary diabetic complications.

Nutrition for diabetic retinopathy: plummeting the inevitable threat of diabetic vision loss.

Diabetic retinopathy (DR) is among the leading causes of preventable blindness. Hyperglycemia, hypertension, hyperlipidemia and anemia majorly predispose its pathogenesis. The current treatment modalities of DR include laser photocoagulation therapy, intravitreal corticosteroids, intravitreal anti-vascular endothelial growth factor (VEGF) agents and vitreo-retinal surgery which are costly, highly invasive, unproven for prolonged use and opted in advanced stages of DR. By then retina already encounters a vast damage. Nutrients by their natural physiological, biochemical and molecular action can preserve retinal structure and functions by interfering with the various pathological steps prompting DR incidence, thereby altering the risk of developing this ocular morbidity. Nutrients can also play a central role in DR patients resistant towards the conventional medical treatments. However due to the byzantine interplay existing between nutrients and DR, the worth of nutrition in curbing this vision-threatening ocular morbidity remains silent. This review highlights how nutrients can halt DR development. A nutritional therapy, if adopted in the initial stages, can provide superior-efficacy over the current treatment modalities and can be a complementary, inexpensive, readily available, anodyne option to the clinically unmet requirement for preventing DR. Assessment of nutritional status is presently considered relevant in various clinical conditions except DR. Body Mass Index (BMI) conferred inconclusive results in DR subjects. Subjective Global Assessment (SGA) of nutritional status has recently furnished relevant association with DR status. By integrating nutritional strategies, the risk of developing DR can be reduced substantially. This review summarizes the subsisting knowledge on nutrition, potentially beneficial for preventing DR and sustaining good vision among diabetic subjects.

The Associations of Dietary Intake of Polyunsaturated Fatty Acids With Diabetic Retinopathy in Well-Controlled Diabetes.

PURPOSE: To assess the associations between dietary intake of polyunsaturated fatty acids (PUFAs) and diabetic retinopathy (DR). METHODS: This was a cross-sectional study of 379 patients (median age: 66.0 years) with diabetes attending a diabetes eye clinic. Daily fatty acid intake was assessed by using a validated Food Frequency Questionnaire and adjusted for energy intake. Diabetic retinopathy was graded from fundus photographs as no DR, nonproliferative DR, or proliferative DR. Patients were categorized as "well-controlled diabetes" (n = 123) and "poorly controlled diabetes" (n = 256), defined as glycated hemoglobin (HbA1c) level < 7.0% or ≥ 7.0%, respectively. RESULTS: There were no associations between any fatty acid intake and DR. However, among patients with well-controlled diabetes, increasing daily intake of PUFAs was associated with a reduced likelihood of the presence (odds ratio [OR]: 0.18; 95% confidence interval [CI]: 0.06-0.59) and severity of DR after adjusting for age, sex, HbA1c, mean arterial blood pressure, and duration of diabetes. Moreover, an increased saturated fatty acid (SFA) intake was associated with increased likelihood of the presence (OR: 2.37; 95% CI: 1.15-4.88) and severity of DR. No association was found among those with poorly controlled diabetes. CONCLUSIONS: Increasing PUFA intake was associated with a reduced likelihood of the presence and severity of DR in well-controlled diabetes, whereas increasing SFA intake was associated with an increased likelihood of the presence and severity of DR. Further studies to confirm this observation are warranted to elucidate the underlying mechanisms and potential role of dietary PUFA and SFA intake in the management of DR.

Mediterranean Diet, Retinopathy, Nephropathy, and Microvascular Diabetes Complications: A Post Hoc Analysis of a Randomized Trial.

OBJECTIVE: To date no clinical trials have evaluated the role of dietary patterns on the incidence of microvascular diabetes complications. We hypothesized that a nutritional intervention based on the Mediterranean diet (MedDiet) would have greater protective effect on diabetic retinopathy and nephropathy than a low-fat control diet. RESEARCH DESIGN AND METHODS: This was a post hoc analysis of a cohort of patients with type 2 diabetes participating in the PREvención con DIeta MEDiterránea (PREDIMED) study, a multicenter randomized nutritional intervention trial conducted in a population at high cardiovascular risk. Individuals with type 2 diabetes who were free of microvascular complications at enrollment (n = 3,614, aged 55-80 years) were randomly assigned to one of three dietary interventions: MedDiet supplemented with extravirgin olive oil (MedDiet+EVOO), MedDiet supplemented with mixed nuts (MedDiet+Nuts), or a low-fat control diet. Two independent outcomes were considered: new onset of diabetic retinopathy and nephropathy. Hazard ratios (HRs) were calculated using multivariable-adjusted Cox regression. RESULTS: During a median follow-up of 6.0 years, we identified 74 new cases of retinopathy and 168 of nephropathy. Compared with the control diet, multivariable-adjusted HRs for diabetic retinopathy were 0.56 (95% CI 0.32-0.97) for the MedDiet+EVOO and 0.63 (0.35-1.11) for the MedDiet+Nuts. No between-group differences were found for nephropathy. When the yearly updated information on adherence to the MedDiet was considered, the HR for retinopathy in the highest versus the lowest quintile was 0.34 (0.13-0.89; P = 0.001 for trend). No significant associations were found for nephropathy. CONCLUSIONS: A MedDiet enriched with EVOO may protect against diabetic retinopathy but not diabetic nephropathy.

Alpha-mangostin attenuation of hyperglycemia-induced ocular hypoperfusion and blood retinal barrier leakage in the early stage of type 2 diabetes rats.

The present study examined effects of alpha-mangostin (α-MG) supplementation on the retinal microvasculature, including ocular blood flow (OBF) and blood-retinal barrier (BRB) permeability in a type 2 diabetic animal model. Male Sprague-Dawley rats were divided into four groups: normal control and diabetes with or without α-MG supplementation. Alpha-mangostin (200 mg/Kg/day) was administered by gavage feeding for 8 weeks. The effects of α-MG on biochemical and physiological parameters including mean arterial pressure (MAP), OBF, and BRB leakage were investigated. Additionally, levels of retinal malondialdehyde (MDA), advance glycation end products (AGEs), receptor of advance glycation end products (RAGE), tumour necrosis factor alpha (TNF-α), and vascular endothelial growth factor (VEGF) were evaluated. The elevated blood glucose, HbA1c, cholesterol, triglyceride, serum insulin, and HOMA-IR were observed in DM2 rats. Moreover, DM2 rats had significantly decreased OBF but statistically increased MAP and leakage of the BRB. The α-MG-treated DM2 rats showed significantly lower levels of retinal MDA, AGEs, RAGE, TNF-α, and VEGF than the untreated group. Interestingly, α-MG supplementation significantly increased OBF while it decreased MAP and leakage of BRB. In conclusion, α-MG supplementation could restore OBF and improve the BRB integrity, indicating its properties closely associated with antihyperglycemic, antioxidant, anti-inflammatory, and antiglycation activities.

N-3 polyunsaturated Fatty acids prevent diabetic retinopathy by inhibition of retinal vascular damage and enhanced endothelial progenitor cell reparative function.

OBJECTIVE: The vasodegenerative phase of diabetic retinopathy is characterized by not only retinal vascular degeneration but also inadequate vascular repair due to compromised bone marrow derived endothelial progenitor cells (EPCs). We propose that n-3 polyunsaturated fatty acid (PUFA) deficiency in diabetes results in activation of the central enzyme of sphingolipid metabolism, acid sphingomyelinase (ASM) and that ASM represents a molecular metabolic link connecting the initial damage in the retina and the dysfunction of EPCs. RESEARCH DESIGN AND METHODS: Type 2 diabetic rats on control or docosahexaenoic acid (DHA)-rich diet were studied. The number of acellular capillaries in the retinas was assessed by trypsin digest. mRNA levels of interleukin (IL)-1ß, IL-6, intracellular adhesion molecule (ICAM)-1 in the retinas from diabetic animals were compared to controls and ASM protein was assessed by western analysis. EPCs were isolated from blood and bone marrow and their numbers and ability to form colonies in vitro, ASM activity and lipid profiles were determined. RESULTS: DHA-rich diet prevented diabetes-induced increase in the number of retinal acellular capillaries and significantly enhanced the life span of type 2 diabetic animals. DHA-rich diet blocked upregulation of ASM and other inflammatory markers in diabetic retina and prevented the increase in ASM activity in EPCs, normalized the numbers of circulating EPCs and improved EPC colony formation. CONCLUSIONS: In a type 2 diabetes animal model, DHA-rich diet fully prevented retinal vascular pathology through inhibition of ASM in both retina and EPCs, leading to a concomitant suppression of retinal inflammation and correction of EPC number and function.

Influence of dietary-fibre intake on diabetes and diabetic retinopathy: Sankara Nethralaya-Diabetic Retinopathy Epidemiology and Molecular Genetic Study (report 26).

BACKGROUND: The present study aims to report the influence of dietary-fibre intake on diabetes and diabetic microangiopathies among subjects >40 years in Urban India. DESIGN: Population-based cross-sectional study. PARTICIPANTS: A total of 1383 patients were included in the study, 1261 diabetics and 122 controls. METHODS: All subjects underwent comprehensive eye examination including assessment of diabetic retinopathy using fundus photography. Dietary-fibre intake was assessed using a validated questionnaire. All questions were validated based on factor analysis (overall communalities value >0.5). The cut-off for low-fibre diet was calculated by the average of study scores (≤ 32 for low-fibre diet). MAIN OUTCOME MEASURES: Prevalence of diabetes in subjects with low-fibre diet versus healthy diet and risk of microangiopathies. RESULTS: Subjects with low-fibre diet intake, had 1.51 times more risk of microalbuminuria than those with a healthy-fibre diet. Similarly, the odds of having diabetic retinopathy and sight-threatening diabetic retinopathy (odds ratio 1.41 [95% CI 1.02-1.94] and odds ratio 2.24 [95% CI 1.01-5.02], respectively) in low-fibre diet subjects were more. Low-fibre diet was consumed predominantly by lower socioeconomic status group (11.9 vs. 6.5, P=0.002). CONCLUSIONS: Subjects with type II diabetes had a lower dietary-fibre intake. The presence of diabetic retinopathy, sight-threatening diabetic retinopathy and microalbuminuria were also associated with lower dietary-fibre intake.

High prevalence of microvascular complications in adults with type 1 diabetes and newly diagnosed celiac disease.

OBJECTIVE: The implications of celiac disease (CD) in adult patients with type 1 diabetes are unknown, with respect to diabetes-related outcomes including glycemic control, lipids, microvascular complications, quality of life, and the effect of a gluten-free diet (GFD). We identified CD in adults with type 1 diabetes and investigated the effect of a GFD on diabetes-related complications. RESEARCH DESIGN AND METHODS: This was a case-control study conducted at a U.K. teaching hospital. Patients with type 1 diabetes aged >16 years (n = 1,000) were assessed for CD. HbA(1c), lipid profile, quality of life, retinopathy stage, nephropathy stage, and degree of neuropathy before and after 1 year on a GFD were assessed. RESULTS: The prevalence of CD was 33 per 1,000 subjects (3.3% [95% CI 2.3-4.6]). At diagnosis of CD, adult type 1 diabetic patients had worse glycemic control (8.2 vs. 7.5%, P = 0.05), lower total cholesterol (4.1 vs. 4.9, P = 0.014), lower HDL cholesterol (1.1 vs. 1.6, P = 0.017), and a higher prevalence of retinopathy (58.3 vs. 25%, P = 0.02), nephropathy (41.6 vs. 4.2%, P = 0.009), and peripheral neuropathy (41.6 vs. 16.6%, P = 0.11). There was no difference in quality of life (P > 0.1). After 1 year on a GFD, only the lipid profile improved overall, but in adherent individuals HbA(1c) and markers for nephropathy improved. CONCLUSIONS: Adults with undetected CD and type 1 diabetes have worse glycemic control and a higher prevalence of retinopathy and nephropathy. Treatment with a GFD for 1 year is safe in adults with type 1 diabetes and does not have a negative impact on the quality of life.

[Vitamins for the eyes? Risks and opportunities for physician and patient]. / Vitamine für das Auge? Risiken und Chancen für Arzt und Patienten.

This article discusses the effects of dietetic measures and specialized food supplements on age-related macular degeneration (AMD) and diabetic retinopathy. The sale of products in doctors' offices is already prohibited by laws governing the medical profession. The results of the Age-Related Eye Disease Study (AREDS) concerning high doses of vitamins and zinc cannot simply be transferred to other doses and substances. Furthermore, there are health risks that have to be examined. Opportunities could arise for both doctor and patient if the AREDS formulation were granted authorization to be marketed as a medicinal product; however, a certain protective effect can be expected only for specific forms of AMD after a careful risk-benefit analysis and assessment within the statutory marketing authorization procedure for medicinal products.