Retinopathy and vision loss in insulin-dependent diabetes in Europe. The EURODIAB IDDM Complications Study

Comparisons of Handheld Retinal Imaging with Optical Coherence Tomography for the Identification of Macular Pathology in Patients with Diabetes

INTRODUCTION

Handheld retinal imaging cameras are relatively inexpensive and highly portable devices that have the potential to significantly expand diabetic retinopathy (DR) screening, allowing a much broader population to be evaluated. However, it is essential to evaluate if these devices can accurately identify vision-threatening macular diseases if DR screening programs will rely on these instruments. Thus, the purpose of this study was to evaluate the detection of diabetic macular pathology using monoscopic macula-centered images using mydriatic handheld retinal imaging compared with spectral domain optical coherence tomography (SDOCT).

METHODS

Mydriatic 40°-60° macula-centered images taken with 3 handheld retinal imaging devices (Aurora [AU], SmartScope [SS], RetinaVue 700 [RV]) were compared with the Cirrus 6000 SDOCT taken during the same visit. Images were evaluated for the presence of diabetic macular edema (DME) on monoscopic fundus photographs adapted from Early Treatment Diabetic Retinopathy Study (ETDRS) definitions (no DME, noncenter-involved DME [non-ciDME], and center-involved DME [ciDME]). Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each device with SDOCT as gold standard.

RESULTS

Severity by ETDRS photos: no DR 33.3%, mild NPDR 20.4%, moderate 14.2%, severe 11.6%, proliferative 20.4%, and ungradable for DR 0%; no DME 83.1%, non-ciDME 4.9%, ciDME 12.0%, and ungradable for DME 0%. Gradable images by SDOCT (N = 217, 96.4%) showed no DME in 75.6%, non-ciDME in 9.8%, and ciDME in 11.1%. The ungradable rate for images (poor visualization in >50% of the macula) was AU: 0.9%, SS: 4.4%, and RV: 6.2%. For DME, sensitivity and specificity were similar across devices (0.5-0.64, 0.93-0.97). For nondiabetic macular pathology (ERM, pigment epithelial detachment, traction retinal detachment) across all devices, sensitivity was low to moderate (0.2-0.5) but highly specific (0.93-1.00).

CONCLUSIONS

Compared to SDOCT, handheld macular imaging attained high specificity but low sensitivity in identifying macular pathology. This suggests the importance of SDOCT evaluation for patients suspected to have DME on fundus photography, leading to more appropriate referral refinement.

Blood pressure control for diabetic retinopathy

BACKGROUND

Diabetic retinopathy is a common complication of diabetes and a leading cause of visual impairment and blindness. Research has established the importance of blood glucose control to prevent development and progression of the ocular complications of diabetes. Concurrent blood pressure control has been advocated for this purpose, but individual studies have reported varying conclusions regarding the effects of this intervention.

OBJECTIVES

To summarize the existing evidence regarding the effect of interventions to control blood pressure levels among diabetics on incidence and progression of diabetic retinopathy, preservation of visual acuity, adverse events, quality of life, and costs.

SEARCH METHODS

We searched several electronic databases, including CENTRAL, and trial registries. We last searched the electronic databases on 3 September 2021. We also reviewed the reference lists of review articles and trial reports selected for inclusion.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in which either type 1 or type 2 diabetic participants, with or without hypertension, were assigned randomly to more intense versus less intense blood pressure control; to blood pressure control versus usual care or no intervention on blood pressure (placebo); or to one class of antihypertensive medication versus another or placebo.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently reviewed the titles and abstracts of records identified by the electronic and manual searches and the full-text reports of any records identified as potentially relevant. The included trials were independently assessed for risk of bias with respect to outcomes reported in this review.

MAIN RESULTS

We included 29 RCTs conducted in North America, Europe, Australia, Asia, Africa, and the Middle East that had enrolled a total of 4620 type 1 and 22,565 type 2 diabetic participants (sample sizes from 16 to 4477 participants). In all 7 RCTs for normotensive type 1 diabetic participants, 8 of 12 RCTs with normotensive type 2 diabetic participants, and 5 of 10 RCTs with hypertensive type 2 diabetic participants, one group was assigned to one or more antihypertensive agents and the control group to placebo. In the remaining 4 RCTs for normotensive participants with type 2 diabetes and 5 RCTs for hypertensive type 2 diabetic participants, methods of intense blood pressure control were compared to usual care. Eight trials were sponsored entirely and 10 trials partially by pharmaceutical companies; nine studies received support from other sources; and two studies did not report funding source. Study designs, populations, interventions, lengths of follow-up (range less than one year to nine years), and blood pressure targets varied among the included trials. For primary review outcomes after five years of treatment and follow-up, one of the seven trials for type 1 diabetics reported incidence of retinopathy and one trial reported progression of retinopathy; one trial reported a combined outcome of incidence and progression (as defined by study authors). Among normotensive type 2 diabetics, four of 12 trials reported incidence of diabetic retinopathy and two trials reported progression of retinopathy; two trials reported combined incidence and progression. Among hypertensive type 2 diabetics, six of the 10 trials reported incidence of diabetic retinopathy and two trials reported progression of retinopathy; five of the 10 trials reported combined incidence and progression. The evidence supports an overall benefit of more intensive blood pressure intervention for five-year incidence of diabetic retinopathy (11 studies; 4940 participants; risk ratio (RR) 0.82, 95% confidence interval (CI) 0.73 to 0.92; I2 = 15%; moderate certainty evidence) and the combined outcome of incidence and progression (8 studies; 6212 participants; RR 0.78, 95% CI 0.68 to 0.89; I2 = 42%; low certainty evidence). The available evidence did not support a benefit regarding five-year progression of diabetic retinopathy (5 studies; 5144 participants; RR 0.94, 95% CI 0.78 to 1.12; I2 = 57%; moderate certainty evidence), incidence of proliferative diabetic retinopathy, clinically significant macular edema, or vitreous hemorrhage (9 studies; 8237 participants; RR 0.92, 95% CI 0.82 to 1.04; I2 = 31%; low certainty evidence), or loss of 3 or more lines on a visual acuity chart with a logMAR scale (2 studies; 2326 participants; RR 1.15, 95% CI 0.63 to 2.08; I2 = 90%; very low certainty evidence). Hypertensive type 2 diabetic participants realized more benefit from intense blood pressure control for three of the four outcomes concerning incidence and progression of diabetic retinopathy. The adverse event reported most often (13 of 29 trials) was death, yielding an estimated RR 0.87 (95% CI 0.76 to 1.00; 13 studies; 13,979 participants; I2 = 0%; moderate certainty evidence). Hypotension was reported in two trials, with an RR of 2.04 (95% CI 1.63 to 2.55; 2 studies; 3323 participants; I2 = 37%; low certainty evidence), indicating an excess of hypotensive events among participants assigned to more intervention on blood pressure.

AUTHORS' CONCLUSIONS

Hypertension is a well-known risk factor for several chronic conditions for which lowering blood pressure has proven to be beneficial. The available evidence supports a modest beneficial effect of intervention to reduce blood pressure with respect to preventing diabetic retinopathy for up to five years, particularly for hypertensive type 2 diabetics. However, there was a paucity of evidence to support such intervention to slow progression of diabetic retinopathy or to affect other outcomes considered in this review among normotensive diabetics. This weakens any conclusion regarding an overall benefit of intervening on blood pressure in diabetic patients without hypertension for the sole purpose of preventing diabetic retinopathy or avoiding the need for treatment for advanced stages of diabetic retinopathy.

Organophosphate esters exposure in relation to glucose homeostasis and type 2 diabetes in adults: A national cross-sectional study from the national health and nutrition survey

BACKGROUND

Exposure to organophosphate esters (OPEs) may be associated with impaired glucose homeostasis and increased risk of type 2 diabetes (T2D) in adolescent. However, the evidence in general population is scarce, especially for glucose homeostasis. We used data from the National Health and Nutrition Examination Survey (NHANES) 1999-2008 and 2011-2012 to investigate the relationship of urinary OPEs with glucose homeostasis and T2D in adults.

METHODS

A total of 5347 participants aged ≥20 years were included. The exposures were the concentrations of urinary OPEs metabolites [dimethyl phosphate (DMP), dimethyl thiophosphate (DMTP), dimethyl dithiophosphate (DMDTP), diethyl phosphate (DEP), diethyl thiophosphate (DETP), and diethyl dithiophosphate (DEDTP)]. The health outcomes were prevalence of T2D and glucose homeostasis [i.e., fasting glucose, 2-h plasma glucose during a 75-g oral glucose tolerance test (2 h-OGTT), serum insulin, HemoglobinA1c (HbA1c), HOMA-IR, and HOMA-β]. The multivariable linear regression model was used to evaluate the relationship between OPEs and glucose homeostasis. The multivariable binary logistic regression analysis was used to investigate the relationship between OPEs and prevalence of T2D.

RESULTS

The OPEs compound DMTP was significantly associated with higher levels of serum insulin [β (95%confidence interval, CI) = 0.21 (0.06,0.36), for one unit increase in log₂-transformed exposure] and HOMA IR [β (95%CI) = 0.08 (0.02,0.14)], and increased odds of T2D [odds ratio (95% CI) = 1.05 (1.01-1.08)]. Other OPEs were not statistically associated with the serum markers for glucose homeostasis or T2D prevalence.

CONCLUSION

Our study found that the OPEs compound DMTP might be associated with impaired glucose homeostasis and may increase the prevalence of T2D in U.S. adults. Further longitudinal or experimental studies are warranted to verify our findings in different populations and different OPEs concentrations.

Artificial Intelligence-Based Teleopthalmology Application for Diagnosis of Diabetics Retinopathy

Diabetic Retinopathy (DR) is one of the leading causes of blindness for people who have diabetes in the world. However, early detection of this disease can essentially decrease its effects on the patient. The recent breakthroughs in technologies, including the use of smart health systems based on Artificial intelligence, IoT and Blockchain are trying to improve the early diagnosis and treatment of diabetic retinopathy. In this study, we presented an AI-based smart teleopthalmology application for diagnosis of diabetic retinopathy. The app has the ability to facilitate the analyses of eye fundus images via deep learning from the Kaggle database using Tensor Flow mathematical library. The app would be useful in promoting mHealth and timely treatment of diabetic retinopathy by clinicians. With the AI-based application presented in this paper, patients can easily get supports and physicians and researchers can also mine or predict data on diabetic retinopathy and reports generated could assist doctors to determine the level of severity of the disease among the people.

Relation between lipid profile, blood pressure and retinopathy in diabetic patients in King Abdulaziz University hospital: a retrospective record review study

BACKGROUND

Diabetic retinopathy (DR) is a major cause of blindness worldwide, threatening the vision of approximately 10% of patients with diabetes. Many studies have demonstrated that intensive control of the risk factors for DR is essential to reduce the onset and progression of DR. Currently, the relationship between lipid profile and DR is still unclear, especially in Saudi Arabia. We aimed to assess the correlation between both the development and severity of DR with lipid profile and blood pressure among the diabetic patients at the King Abdul-Aziz University hospital in Jeddah, Saudi Arabia.

METHODS

This was a retrospective record review study of 298 diabetic patients diagnosed with DR. Retinal findings were correlated to serum lipids levels using univariate, bivariate, and multivariate analysis.

RESULTS

This study included 298 participants with DR. Triglyceride levels, systolic blood pressure, low-density lipoprotein cholesterol levels, and presence of macular edema were significantly associated with DR progression (P = 0.012, P = 0.001, P = 0.002). Other parameters, including total cholesterol, high-density lipoprotein cholesterol, HbA1C, body mass index, age, were not significantly associated with DR.

CONCLUSION

Elevation in serum triglyceride levels and systolic blood pressure showed a statically significant association with diabetic retinopathy. Controlling these factors may help preventing progression and occurrence of diabetic retinopathy among diabetic patients.

Diabetic retinopathy and visual impairment in a Norwegian diabetic coast population with a high dietary intake of fish oils. An observational study

PURPOSE

To present retinal and visual findings in a Norwegian west coast diabetic population and to elucidate the effect of dietary intake of marine polyunsaturated fatty acids (PUFAs) on the development of diabetic retinopathy (DR).

METHODS

In an eye practice in an archipelago of 314 km², serving a population of about 40 000, we recorded the prevalence of visual impairment and DR in a referred diabetic population. 510 consecutive patients were included, 238 females and 272 males. 50 patients had type I and 460 had type II diabetes mellitus (DM). Self-reported medication, diet supplements, HbA1c and fish consumption were registered.

RESULTS

In the type I group, the median age was 44.5 and median DM duration 11.5 years [1-44]. 48% had photographic evidence of DR, 8 patients (16%) had proliferative retinopathy (PDR), and 6 patients (12%) had diabetic macular oedema (DME). All had best-corrected visual acuity (BCVA) of 0.5 (log MAR 0.3) or better in the best eye. In the type II group, the median DM duration was 8 years [1-53], and median age was 66. 98% had best eye BCVA at or better than 0.5 (log MAR 0.3) in the best eye.

CONCLUSION

None of the 510 patients had BCVA worse than 0.3 (log MAR 0.48) due to diabetic retinopathy. Compared to similar studies, we found a very low visual impairment rate. A possible protective effect of PUFA on the prevalence and progression of diabetic microangiopathy including retinopathy is discussed.

Air Pollutant Particles, PM2.5, Exposure and Glaucoma in Patients with Diabetes: A National Population-Based Nested Case-Control Study

The global prevalence of diabetes mellitus (DM) has reached 20%. Air pollutants with a particle size of less than 2.5 μm (PM_2.5) are a globally recognized risk factor for diabetes and glaucoma. We examined whether the risk of glaucoma would decrease or increase when patients with DM were exposed to different PM_2.5 concentrations. Data were obtained from the National Health Insurance Research Database (NHIRD) of Taiwan and the Air Quality Monitoring Network between 2008 and 2013. This nested case-control study involved 197 DM patients with glaucoma and 788 DM patients without glaucoma. Cases and controls were matched (1:4) by gender, age (±5 years), and index date (±6 months), and their data were entered in a logistic regression model adjusted for gender, age, urbanization level, income level, and comorbidities. The odds ratio (OR) of glaucoma at PM_2.5 exposure concentration in the fourth quartile (Q4) compared with in the first quartile (Q1) was 1.7 (95% CI: 1.084-2.764). For glaucoma risk, the OR was 1.013 (95% CI: 1.006-1.020) at a PM2.5 exposure concentration in Q1, 1.004 (95% CI: 1.001-1.007) in the third quartile (Q3), and 1.003 (95% CI: 1.001-1.004) in Q4. In the subgroup analysis of patients living in non-emerging towns and non-agricultural towns, the OR for glaucoma in Q4 compared with in Q1 was 2.1 (95% CI: 1.229-3.406) and 1.8 (95% CI: 1.091-2.803), respectively (p trend = 0.001 and 0.011). For patients without migraine, the OR for glaucoma was 1.7 (95% CI: 1.074-2.782; p = 0.006). These results demonstrate that, for patients with DM, PM_2.5 increased the risk of glaucoma and PM_2.5 was an independent risk factor for glaucoma in patients with DM.

Remnant cholesterol predicts progression of diabetic nephropathy and retinopathy in type 1 diabetes

BACKGROUND

We aimed to assess whether remnant cholesterol concentration and variability predict the progression of diabetic nephropathy (DN) and severe diabetic retinopathy (SDR) in type 1 diabetes.

METHODS

This observational prospective study covered 5150 FinnDiane Study participants. Remnant cholesterol was calculated as total cholesterol - LDL cholesterol - HDL cholesterol and variability as the coefficient of variation. DN category was based on consensus albuminuria reference limits and the progression status was confirmed from medical files. SDR was defined as retinal laser treatment. For 1338 individuals, the severity of diabetic retinopathy (DR) was graded using the ETDRS classification protocol. Median (IQR) follow-up time was 8.0 (4.9-13.7) years for DN and 14.3 (10.4-16.3) for SDR.

RESULTS

Remnant cholesterol (mmol L^-1 ) was higher with increasing baseline DN category (P < 0.001). A difference was also seen comparing non-progressors (0.41 [0.32-0.55]) with progressors (0.55 [0.40-0.85]), P < 0.001. In a Cox regression analysis, remnant cholesterol predicted DN progression, independently of diabetes duration, sex, HbA_1c , systolic blood pressure, smoking, BMI, estimated glucose disposal rate and estimated glomerular filtration rate (HR: 1.51 [1.27-1.79]). Remnant cholesterol was also higher in those who developed SDR (0.47 [0.36-0.66]) than those who did not (0.40 [0.32-0.53]), P < 0.001, and the concentration increased stepwise with increasing DR severity (P < 0.001). Regarding SDR, the HR for remnant cholesterol was 1.52 (1.26-1.83) with the most stringent adjustment. However, remnant cholesterol variability was not independently associated with the outcomes.

CONCLUSIONS

Remnant cholesterol concentration, but not variability, predicts DN progression and development of SDR. However, it remains to be elucidated whether the associations are causal or not.

LDL cholesterol level as a risk factor for retinopathy and nephropathy in children and adults with type 1 diabetes mellitus: A nationwide cohort study

BACKGROUND

Microvascular complications are common in people with diabetes, where poor glycaemic control is the major contributor. The aim of this study was to explore the association between elevated LDL cholesterol levels and the risk of retinopathy or nephropathy in young individuals with type 1 diabetes.

METHODS

This was a nationwide observational population-based cohort study, including all children and adults with a duration of type 1 diabetes of ≤ 10 years, identified in the Swedish National Diabetes Register between 1998 and 2017. We calculated the crude incidence rates with 95% confidence intervals (CIs) and used multivariable Cox regression to estimate crude and adjusted hazard ratios (HRs) of retinopathy or nephropathy in four LDL cholesterol categories: <2.6 (Reference), 2.6-3.4, 3.4-4.1 and > 4.1 mmol L^-1 .

RESULTS

In total, 11 024/12 350 (retinopathy/nephropathy, both cohorts, respectively) children and adults (median age 21 years, female 42%) were followed up to 28 years from diagnosis until end of study. Median duration of diabetes when entering the study was 6 and 7 years in the retinopathy and nephropathy cohort, respectively. Median LDL cholesterol was 2.4 mmol L^-1 , and median HbA1c level was 61 mmol mol^-1 (7.7 %). After multivariable adjustment, the HRs (95% CI) for retinopathy in individuals with LDL cholesterol levels of 2.6-3.4, 3.4-4.1 or > 4.1 mmol L^-1 were as follows: 1.13 (1.03-1.23), 1.16 (1.02-1.32) and 1.18 (0.99-1.41), compared with the reference. The corresponding numbers for nephropathy were as follows: 1.15 (0.96-1.32), 1.30 (1.03-1.65) and 1.41 (1.06-1.89).

CONCLUSIONS

Young individuals with type 1 diabetes exposed to high LDL cholesterol levels have an increased risk of retinopathy and nephropathy independent of glycaemia and other identified risk factors for vascular complications.

Predictors for diabetic retinopathy progression-findings from nominal group technique and Evidence review

Objectives

Risk stratification is needed for patients referred to hospital eye services by Diabetic Eye Screening Programme UK. This requires a set of candidate predictors. The literature contains a large number of predictors. The objective of this research was to arrive at a small set of clinically important predictors for the outcome of the progression of diabetic retinopathy (DR). They need to be evidence based and readily available during the clinical consultation.

Methods and analysis

Initial list of predictors was obtained from a systematic review of prediction models. We sought the clinical expert opinion using a formal qualitative study design. A series of nominal group technique meetings to shorten the list and to rank the predictors for importance by voting were held with National Health Service hospital-based clinicians involved in caring for patients with DR in the UK. We then evaluated the evidence base for the selected predictors by critically appraising the evidence.

Results

The source list was presented at nominal group meetings (n=4), attended by 44 clinicians. Twenty-five predictors from the original list were ranked as important predictors and eight new predictors were proposed. Two additional predictors were retained after evidence check. Of these 35, 21 had robust supporting evidence in the literature condensed into a set of 19 predictors by categorising DR.

Conclusion

We identified a set of 19 clinically meaningful predictors of DR progression that can help stratify higher-risk patients referred to hospital eye services and should be considered in the development of an individual risk stratification model.

Study design

A qualitative study and evidence review.

Setting

Secondary eye care centres in North East, Midlands and South of England.

Changing trends in the prevalence of diabetic retinopathy in type 1 diabetes mellitus from 1990 to 2018: A retrospective study in a Portuguese population

PURPOSE

To estimate the prevalence of diabetic retinopathy /(DR) in a Portuguese population with type 1 diabetes (T1DM).

METHODS

Retrospective review of all patients with T1DM, whose reference center was Centro Hospitalar de São João, a tertiary center in Portugal, who were diagnosed between 1990 and 2018. DR was classified based on fundus examination in medical records as (0) no evidence of retinopathy, (1) mild non-proliferative retinopathy (NPDR); (2) moderate to severe non-proliferative retinopathy (NPDR) and (3) proliferative retinopathy (PDR). Patients were classified according to the eye with a worse retinopathy stage. Follow-up was considered as time between the diagnosis of diabetes and the last funduscopic evaluation.

RESULTS

233 patients met the inclusion and exclusion criteria. The prevalence of any DR at less than 5, 10, 15, 20 and more than 20-years of DM was 1.8%, 10.4%, 34.8%, 54.1% and 71.2% respectively. The overall prevalence of DR was 43.3% (n = 101). At the last observation, 43 patients (18.5%) had mild NPDR, 34 patients (14.6%) had moderate to severe NPDR and 24 patients (10.3%) had PDR. The longer the disease duration, the higher the number of patients with DR.

CONCLUSION

The prevalence of DR in our cohort was 34.8% after 15 years of systemic disease and 54.1% after 20 years, which is lower than what has been reported in the literature. Further multicentric prospective studies, are needed to clarify changes in the epidemiology of DR in type 1 diabetics.

Automatic Identification and Intuitive Map Representation of the Epiretinal Membrane Presence in 3D OCT Volumes

Optical Coherence Tomography (OCT) is a medical image modality providing high-resolution cross-sectional visualizations of the retinal tissues without any invasive procedure, commonly used in the analysis of retinal diseases such as diabetic retinopathy or retinal detachment. Early identification of the epiretinal membrane (ERM) facilitates ERM surgical removal operations. Moreover, presence of the ERM is linked to other retinal pathologies, such as macular edemas, being among the main causes of vision loss. In this work, we propose an automatic method for the characterization and visualization of the ERM's presence using 3D OCT volumes. A set of 452 features is refined using the Spatial Uniform ReliefF (SURF) selection strategy to identify the most relevant ones. Afterwards, a set of representative classifiers is trained, selecting the most proficient model, generating a 2D reconstruction of the ERM's presence. Finally, a post-processing stage using a set of morphological operators is performed to improve the quality of the generated maps. To verify the proposed methodology, we used 20 3D OCT volumes, both with and without the ERM's presence, totalling 2428 OCT images manually labeled by a specialist. The most optimal classifier in the training stage achieved a mean accuracy of 91 . 9 % . Regarding the post-processing stage, mean specificity values of 91 . 9 % and 99 . 0 % were obtained from volumes with and without the ERM's presence, respectively.

Long-term exposure to ambient fine particulate matter (PM2.5) and incident type 2 diabetes: a longitudinal cohort study

AIMS/HYPOTHESIS

Information on the associations of long-term exposure to fine particulate matter (with an aerodynamic diameter less than 2.5 μm; PM_2.5) with the development of type 2 diabetes is scarce, especially for south-east Asia, where most countries are experiencing serious air pollution. This study aimed to investigate the long-term effects of exposure to ambient PM_2.5 on the incidence of type 2 diabetes in a population of Taiwanese adults.

METHODS

A total of 147,908 participants without diabetes, at least 18 years of age, were recruited in a standard medical examination programme between 2001 and 2014. They were encouraged to take medical examinations periodically and underwent at least two measurements of fasting plasma glucose (FPG). Incident type 2 diabetes was identified as FPG ≥7 mmol/l or self-reported physician-diagnosed diabetes in the subsequent medical visits. The PM_2.5 concentration at each participant's address was estimated using a satellite-based spatiotemporal model with a resolution of 1 × 1 km². The 2 year average of PM_2.5 concentrations (i.e. the year of and the year before the medical examination) was treated as an indicator of long-term exposure to ambient PM_2.5 air pollution. We performed Cox regression models with time-dependent covariates to analyse the long-term effects of exposure to PM_2.5 on the incidence of type 2 diabetes. A wide range of covariates were introduced in the models to control for potential effects, including age, sex, education, season, year, smoking status, alcohol drinking, physical activity, vegetable intake, fruit intake, occupational exposure, BMI, hypertension and dyslipidaemia (all were treated as time-dependent covariates except for sex).

RESULTS

Compared with the participants exposed to the first quartile of ambient PM_2.5, participants exposed to the second, third and fourth quartiles of ambient PM_2.5 had HRs of 1.28 (95% CI 1.18, 1.39), 1.27 (95% CI 1.17, 1.38) and 1.16 (95% CI 1.07, 1.26), respectively, for the incidence of type 2 diabetes. Participants who drank occasionally or regularly (more than once per week) or who had a lower BMI (<23 kg/m²) were more sensitive to the long-term effects of exposure to ambient PM_2.5.

CONCLUSIONS/INTERPRETATION

Long-term exposure to ambient PM_2.5 appears to be associated with a higher risk of developing type 2 diabetes in this Asian population experiencing high levels of air pollution.

Are blood lipids associated with microvascular complications among type 2 diabetes mellitus patients? A cross-sectional study in Shanghai, China

BACKGROUND

Although there are several studies to investigate the association between blood lipids and microvascular complications, these studies reported conflicting results. The aim of the current study was to explore the association between blood lipid parameters and the risk of microvascular complications, especially the dose-response association between them, among community patients with type 2 diabetes mellitus (T2DM) in Shanghai, China.

METHODS

The cross-sectional study was conducted in 6 community health service centers in Shanghai between December 2014 and December 2016.The associations between blood lipids and diabetic kidney disease (DKD) or diabetic retinopathy (DR) were assessed using multiple logistic regression. Restricted cubic spline (RCS) was employed to estimate the dose-response relation of blood lipids and the risk of microvascular complications.

RESULTS

A total of 3698 participants were included in the final analysis to study the association between blood lipids and DKD, wherein 33.2% of participants had DKD and 1374 were included for the analysis of the association between blood lipids and DR, wherein 23.2% of participants had DR. DKD odds ratio was increased by 1.16(95%CI,1.08-1.25), 1.21(95%CI,1.13-1.30), 1.18(95%CI,1.10-1.26) for comparing fourth to first quartiles of triglycerides (TG), TG/high-density lipoprotein cholesterol (HDL-C), non-HDL-C/HDL-C, respectively, and decreased by 0.83(95%CI,0.78-0.89) for comparing fourth to first quartiles of HDL-C. Furthermore, the dose-response association between TG, HDL-C, TG/HDL-C, non-HDL-C/HDL-C and the risk of DKD demonstrated turning points in TG of 1.90 mmol/L, HDL-C of 1.62 mmol/L, TG/HDL-C of 2.00, non-HDL-C/HDL-C of 3.09, respectively. However, no significant association was found between blood lipid parameters and DR.

CONCLUSIONS

This community-based study indicated that TG, HDL-C, TG/HDL-C, non-HDL-C/HDL-C were independently associated with DKD but not DR.

A multicentre study evaluating the risk and prevalence of diabetic retinopathy in children and young people with type 1 diabetes mellitus

INTRODUCTION

There is currently limited data published on the prognostic factors and prevalence of diabetic eye disease in children and young people (CYP) with Type 1 diabetes mellitus (T1DM), yet diabetic retinopathy remains one of the commonest causes of blindness in young adults. The aim of this study was to determine the risk and prevalence of diabetic retinopathy (DR) and to evaluate the risk factors associated with diabetic retinopathy in CYP with T1DM.

METHODS

All CYP with Type 1 diabetes between 12 and 18 years of age, registered with the regional diabetic retinopathy screening programme were evaluated from 2012 to 2013 in four diabetes units within the north west region of the United Kingdom. Patients who had evidence of diabetic retinopathy were reviewed to identify risk factors for presence or absence of diabetic retinopathy.

RESULTS

237 patients between the ages 12-18 years were included in the. The prevalence of diabetic retinopathy was 11%. Out of 27 patients with evidence of diabetic retinopathy, 44% were reported as background changes and 56% had pre-proliferative DR. Significant risk factors for diabetic retinopathy disease in the population using univariate analyses were duration of diabetes, puberty, age at diagnosis and mean HbA1c in the preceding 12 months. Multivariate logistic regression analysis found age of diagnosis (p = 0.04) and mean HbA1c as significant independent risk factors for presence of diabetic retinopathy (p = 0.02).

CONCLUSIONS

The prevalence of diabetic retinopathy in this paediatric population was 11%. Early age at diagnosis and poor metabolic control are independent risk factors for diabetic retinopathy.

Prevalence of Blindness and Visual Impairment among Jordanian Diabetics

PURPOSE

To investigate the prevalence of blindness and visual impairment among a population of Jordanian diabetics.

METHODS

A total of 986 diabetic patients were fully assessed, including complete history, examination, and laboratory tests. All patients underwent detailed eye examination, which included visual acuity, slit-lamp examination, tonometry, funduscopy, and fundus fluorescein angiography (FFA).

RESULTS

Of all patients examined, 53.2% were male and 46.8% were female. The mean age and duration of diabetes were 55.3 and 11.9 years. Of all patients, 93.3% had type 2 while 6.7% had type 1 diabetes mellitus (DM). Over half (50.3%) were on oral hypoglycemic agents, 34% on insulin, and 14.5% on both types of treatment, whereas only 1.2% were on diet alone. The mean value for HbA1c was 7.7%. The prevalence of blindness among participants was found to be 7.4%, while 10.1% were visually impaired. Diabetic retinopathy (DR) was present in 64.1%, 37.8% had cataract, and 8.7% had undergone cataract surgery. Using multivariate logistic regression analysis, visual impairment was significantly associated with age, treatment of diabetes, and DR, while only age and retinopathy were significantly related to blindness.

CONCLUSIONS

DM is a common disease in Jordan and DR is highly prevalent among Jordanian diabetics. National screening and educational programs are highly needed to reduce the risk of blindness and visual impairment among diabetic patients.

Effect of Automobile Travel Time Between Patients' Homes and Ophthalmologists' Offices on Screening for Diabetic Retinopathy

PURPOSE

The accessibility of ophthalmologists appears to influence the quality of screening for diabetic retinopathy (DR). The principal objective of this study was to analyze the effect of automobile travel time to the closest ophthalmologist on the time to DR screening.

METHODS

This historical cohort study used reimbursement databases from the principal national health insurance fund. Patients were included if they had been reimbursed at least thrice for oral antidiabetic medications in the 12 months before the study start date. Patients were followed up from January 1, 2008, for 4 years. The expected event was a DR screening by an ocular fundus examination. The automobile travel time to the nearest ophthalmologist was calculated by the distance between communes, estimated by appropriate software. A Kaplan-Meier curve and a multivariate Cox model were used to model the effect of travel time on the time until DR screening. A sensitivity analysis of travel time described the results of the Cox model.

RESULTS

At the start of 2008, 6,573 patients living in 328 different municipalities were included. The multivariate model found that patients living 60 min or more away from an ophthalmologist had a lower instantaneous probability of DR screening than those living <30 min away (adjusted risk ratio = 0.82; 95% confidence interval 0.71-0.95; p = 0.009). The sensitivity analysis showed that this difference became significant at 35 min of travel time.

CONCLUSION

Increased automobile travel time for patients with diabetes to the nearest ophthalmologist was associated with a longer time to DR screening.

The DIabetic REtinopathy Candesartan Trials (DIRECT) Programme: baseline characteristics

Renin-angiotensin system blockade has been shown to be superior to other antihypertensive therapy in slowing progression of renal disease in diabetic patients, but questions remain regarding diabetic retinopathy. The primary objective of the DIabetic REtinopathy Candesartan Trials (DIRECT) Programme is to examine primary (incidence) and secondary (progression) prevention of diabetic retinopathy when blocking angiotensin II type 1-receptors with candesartan in normoalbuminuric, normotensive Type 1 diabetic patients, and secondary prevention only in normoalbuminuric, normotensive or treated hypertensive Type 2 diabetic patients. The secondary objectives include examining the effect of candesartan treatment on urinary albumin excretion rate (UAER) in each of the three studies and to examine the incidence of proliferative retinopathy in all three populations combined.

Standardised investigations for patients at enrolment include blood pressure measurement analysis of HbA1C and serum lipids, and a detailed ophthalmological examination. Retinopathy and UAER outcomes are assessed yearly. Retinopathy is graded centrally, based on seven-field stereo photographs using the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol. Randomisation was performed when the results of retinal gradings were available, and treatment with 16 mg candesartan cilexetil or matching placebo was initiated; the dose was increased to 32 mg after one month. Calculations of UAER are based on two timed overnight urine collections.

A sample size re-assessment was carried out when approximately 70% of the patients had been randomised in the DIRECT Programme to ensure the results to be conclusive.

In total, 5,231 patients were randomised in the DIRECT Programme in 30 countries. One thousand, four hundred and twenty one and 1,905 patients are evaluated in the primary and secondary prevention studies in Type 1 diabetes, respectively and 1,905 patients in the secondary prevention study in Type 2 diabetes.

HbA1C showed mean values of 8.1, 8.5 and 8.2% for the Type 1 primary, Type 1 secondary and Type 2 secondary prevention studies, respectively. In the Type 1 secondary prevention study, 49% of the patients had mild nonproliferative retinopathy (level 20) in at least one eye, and 9% had moderate-moderately severe non-proliferative retinopathy (level 43—47). In Type 2 patients, 17% had level 43—47 and the remainder less severe retinopathy.

Suitability of a Low-Cost, Handheld, Nonmydriatic Retinograph for Diabetic Retinopathy Diagnosis

Purpose

We assessed the suitability of a low-cost, handheld, nonmydriatic retinograph, namely the Horus DEC 200, for diabetic retinopathy (DR) diagnosis. Two factors were considered: ease of image acquisition and image quality.

Methods

One operator acquired fundus photographs from 54 patients using the Horus and AFC-330, a more expensive, nonportable retinograph. Satisfaction surveys were filled out by patients. Then, two retinologists subjectively assessed image quality and graded DR severity in one eye of each patient. Objective image quality indices also were computed.

Results

During image acquisitions, patients had difficulty locating the fixation target inside the Horus: by default, 53.7% of them had to fixate external points with the contralateral eye, as opposed to none of them using the AFC-330 (P < 0.0001). This issue impacted the duration of image acquisitions. Images obtained by the Horus were of significantly lower quality according to the experts (P = 0.0002 and P = 0.0004) and to the objective criterion (P < 0.0001). As a result, up to 20.4% of eyes were inadequate for interpretation, as opposed to 9.3% using the AFC-330. However, no significant difference was found in terms of DR severity according to both experts (P = 0.557 and P = 0.156).

Conclusions

The Horus can be used to screen DR, but at the cost of longer examination times and higher proportions of patients referred to an ophthalmologist due to inadequate image quality.

Translational Relevance

The Horus is adequate to screen DR, for instance in primary care centers or in mobile imaging units.

Lipids and Diabetic Retinopathy

The relationship between lipids and the development and/or severity of diabetic retinopathy (DR) is complex. Large epidemiologic studies suggest an inconsistent and overall modest association between serum triglycerides or major cholesterol species and the severity of DR; however, certain specific lipoprotein species may have stronger associations with DR severity, suggesting a pathophysiological role for lipoproteins analogous to that seen in atherosclerosis. In this lipoprotein-mediated DR pathogenesis model, damage to the blood-retinal barrier allows extravasation of lipoprotein species, which are modified in the intraretinal environment, creating substantial local damage. Additionally, hypolipidemic therapy with statins and fibrates--particularly the latter--have been shown to modulate DR in large-scale studies. Since serum lipid profile changes do not necessarily correlate with DR modulation, the efficacy of these agents may be due to their tissue-specific changes in lipoproteins and/or their anti-inflammatory, antioxidative, antiangiogenic, and antiapoptotic functions.

Antihypertensive Drugs and Diabetic Retinopathy in Patients with Type 2 Diabetes

OBJECTIVE

To evaluate the association between the development of sight-threatening diabetic retinopathy (STDR) and antihypertensive drugs (AHDs) use among type 2 diabetic patients with concomitant hypertension.

METHODS

Type 2 diabetic patients aged 20-100 years who had at least one prescription for AHDs between 2000 and 2011 were identified from the Longitudinal Health Insurance Database (LHID) 2005. The incidence rates of STDR were followed and Cox proportional hazard models were used to analyze the risk associated with AHDs.

RESULTS

Users of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) were associated with a significantly higher risk than users of calcium channel blockers (CCBs), independent of baseline characteristics. After adjusting for time-varying use of concomitant medications for propensity score-matched or -unmatched cohorts, the results showed that patients receiving ACEIs/ARBs and CCBs were associated with a significantly greater risk compared with β-blocker users.

CONCLUSIONS

Our study did not support a superiority of ACEIs/ARBs and CCBs over β-blockers for lowering the progression of diabetic retinopathy.

Risk factors associated with diabetic retinopathy among type 2 diabetes patients at teaching hospital in Malaysia

BACKGROUND

Diabetic retinopathy (DR) is the leading cause of blindness in the United States and it is the leading cause of new cases of blindness in adults aged 20-74. It is estimated that about 20% of patients with type 2 DM have evidence of diabetic retinopathy at diagnosis with diabetes.

OBJECTIVE

To evaluate the prevalence of DR and to determine risk factors related to diabetic retinopathy among type 2 diabetes patients attending endocrinology clinics at Hospital Universiti Sains Malaysia (HUSM).

SUBJECTS AND METHODS

The study design was observational prospective longitudinal follow-up study, the study was conducted with sample of 1077 type 2 diabetes mellitus outpatient recruited via attended the diabetes clinics at HUSM. Diagnosis of retinopathy is based on finding the diagnostic signs of retinopathy on eye exams by fundoscopy. Logistic regression analysis was used to assess the independent variables that affect the development of retinopathy.

RESULTS

The prevalence of retinopathy was 39.3%. It has been noticed from this study findings, that the progression of retinopathy is been influenced by five independent risk factors such as duration of diabetes, presence neuropathy, total cholesterol at second and third visit and createnine clearance.

CONCLUSION

DR is highly prevalent among type 2 DM. The progression of retinopathy is been influenced by five independent risk factors such as duration of diabetes, presence neuropathy, total cholesterol at second and third visit and createnine clearance. DR is a serious diabetic complication and public health strategies are required in order to reduce its risk factors and decrease its prevalence.

Blood pressure control for diabetic retinopathy

BACKGROUND

Diabetic retinopathy is a common complication of diabetes and a leading cause of visual impairment and blindness. Research has established the importance of blood glucose control to prevent development and progression of the ocular complications of diabetes. Simultaneous blood pressure control has been advocated for the same purpose, but findings reported from individual studies have supported varying conclusions regarding the ocular benefit of interventions on blood pressure.

OBJECTIVES

The primary aim of this review was to summarize the existing evidence regarding the effect of interventions to control or reduce blood pressure levels among diabetics on incidence and progression of diabetic retinopathy, preservation of visual acuity, adverse events, quality of life, and costs. A secondary aim was to compare classes of anti-hypertensive medications with respect to the same outcomes.

SEARCH METHODS

We searched a number of electronic databases including CENTRAL as well as ongoing trial registries. We last searched the electronic databases on 25 April 2014. We also reviewed reference lists of review articles and trial reports selected for inclusion. In addition, we contacted investigators of trials with potentially pertinent data.

SELECTION CRITERIA

We included in this review randomized controlled trials (RCTs) in which either type 1 or type 2 diabetic participants, with or without hypertension, were assigned randomly to intense versus less intense blood pressure control, to blood pressure control versus usual care or no intervention on blood pressure, or to different classes of anti-hypertensive agents versus placebo.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently reviewed titles and abstracts from electronic and manual searches and the full text of any document that appeared to be relevant. We assessed included trials independently for risk of bias with respect to outcomes reported in this review. We extracted data regarding trial characteristics, incidence and progression of retinopathy, visual acuity, quality of life, and cost-effectiveness at annual intervals after study entry whenever provided in published reports and other documents available from included trials.

MAIN RESULTS

We included 15 RCTs, conducted primarily in North America and Europe, that had enrolled 4157 type 1 and 9512 type 2 diabetic participants, ranging from 16 to 2130 participants in individual trials. In 10 of the 15 RCTs, one group of participants was assigned to one or more anti-hypertensive agents and the control group received placebo. In three trials, intense blood pressure control was compared to less intense blood pressure control. In the remaining two trials, blood pressure control was compared with usual care. Five of the 15 trials enrolled type 1 diabetics, and 10 trials enrolled type 2 diabetics. Six trials were sponsored entirely by pharmaceutical companies, seven trials received partial support from pharmaceutical companies, and two studies received support from government-sponsored grants and institutional support.Study designs, populations, interventions, and lengths of follow-up (range one to nine years) varied among the included trials. Overall, the quality of the evidence for individual outcomes was low to moderate. For the primary outcomes, incidence and progression of retinopathy, the quality of evidence was downgraded due to inconsistency and imprecision of estimates from individual studies and differing characteristics of participants.For primary outcomes among type 1 diabetics, one of the five trials reported incidence of retinopathy and one trial reported progression of retinopathy after 4 to 5 years of treatment and follow-up; four of the five trials reported a combined outcome of incidence and progression over the same time interval. Among type 2 diabetics, 5 of the 10 trials reported incidence of diabetic retinopathy and 3 trials reported progression of retinopathy; one of the 10 trials reported a combined outcome of incidence and progression during a 4- to 5-year follow-up period. One trial in which type 2 diabetics participated had reported no primary (or secondary) outcome targeted for this review.The evidence from these trials supported a benefit of more intensive blood pressure control intervention with respect to 4- to 5-year incidence of diabetic retinopathy (estimated risk ratio (RR) 0.80; 95% confidence interval (CI) 0.71 to 0.92) and the combined outcome of incidence and progression (estimated RR 0.78; 95% CI 0.63 to 0.97). The available evidence provided less support for a benefit with respect to 4- to 5-year progression of diabetic retinopathy (point estimate was closer to 1 than point estimates for incidence and combined incidence and progression, and the CI overlapped 1; estimated RR 0.88; 95% CI 0.73 to 1.05). The available evidence regarding progression to proliferative diabetic retinopathy or clinically significant macular edema or moderate to severe loss of best-corrected visual acuity did not support a benefit of intervention on blood pressure: estimated RRs and 95% CIs 0.95 (0.83 to 1.09) and 1.06 (0.85 to 1.33), respectively, after 4 to 5 years of follow-up. Findings within subgroups of trial participants (type 1 and type 2 diabetics; participants with normal blood pressure levels at baseline and those with elevated levels) were similar to overall findings.The adverse event reported most often (7 of 15 trials) was death, yielding an estimated RR 0.86 (95% CI 0.64 to 1.14). Hypotension was reported from three trials; the estimated RR was 2.08 (95% CI 1.68 to 2.57). Other adverse ocular events were reported from single trials.

AUTHORS' CONCLUSIONS

Hypertension is a well-known risk factor for several chronic conditions in which lowering blood pressure has proven to be beneficial. The available evidence supports a beneficial effect of intervention to reduce blood pressure with respect to preventing diabetic retinopathy for up to 4 to 5 years. However, the lack of evidence to support such intervention to slow progression of diabetic retinopathy or to prevent other outcomes considered in this review, along with the relatively modest support for the beneficial effect on incidence, weakens the conclusion regarding an overall benefit of intervening on blood pressure solely to prevent diabetic retinopathy.

Risk factors for development and progression of nonproliferative retinopathy in normoalbuminuric patients with type 1 diabetes

BACKGROUND

The aim of this study was to evaluate risk factors for development and progression of nonproliferative retinopathy (NPR) in normoalbuminuric patients with type 1 diabetes mellitus (T1DM).

METHODS

A total of 223 T1DM with normal renal function and normoalbuminuria were included in this study and followed for 48 months. Photodocumented retinopathy status was made according to the EURODIAB protocol. Urinary albumin excretion rate (UAE) was measured from at least two 24-h urine samples. Possible risk factors for development or progression of NPR were examined in backward stepwise Cox's multiple regression analysis.

RESULTS

The majority of patients (70%) had no retinopathy while 67 (30%) had NPR at baseline. Patients with NPR were older, had longer duration of diabetes, higher systolic blood pressure, BMI, resting heart rate, UAE and lower estimated glomerular filtration rate (p ≤ 0.04 for all). After 48 months 24 patients (10.7%) developed NPR or progressed to proliferative retinopathy. Systolic blood pressure (HR 1.03, CI 1.01-1.05, p=0.02), UAE (HR 1.14, CI 1.07-1.21, p<0.001), and resting heart rate (HR 1.05, CI 1.01-1.09, p=0.006) were significantly associated with development or progression of NPR.

CONCLUSIONS

Our results suggest that retinopathy is present and may progress in T1DM even when coexisting renal disease is excluded. Normoalbuminuric T1DM requires close monitoring for the early detection of retinopathy, especially if they have a higher UAE, systolic blood pressure and resting heart rate.

Predicting major outcomes in type 1 diabetes: a model development and validation study

AIMS/HYPOTHESIS

Type 1 diabetes is associated with a higher risk of major vascular complications and death. A reliable method that predicted these outcomes early in the disease process would help in risk classification. We therefore developed such a prognostic model and quantified its performance in independent cohorts.

METHODS

Data were analysed from 1,973 participants with type 1 diabetes followed for 7 years in the EURODIAB Prospective Complications Study. Strong prognostic factors for major outcomes were combined in a Weibull regression model. The performance of the model was tested in three different prospective cohorts: the Pittsburgh Epidemiology of Diabetes Complications study (EDC, n = 554), the Finnish Diabetic Nephropathy study (FinnDiane, n = 2,999) and the Coronary Artery Calcification in Type 1 Diabetes study (CACTI, n = 580). Major outcomes included major CHD, stroke, end-stage renal failure, amputations, blindness and all-cause death.

RESULTS

A total of 95 EURODIAB patients with type 1 diabetes developed major outcomes during follow-up. Prognostic factors were age, HbA1c, WHR, albumin/creatinine ratio and HDL-cholesterol level. The discriminative ability of the model was adequate, with a concordance statistic (C-statistic) of 0.74. Discrimination was similar or even better in the independent cohorts, the C-statistics being: EDC, 0.79; FinnDiane, 0.82; and CACTI, 0.73.

CONCLUSIONS/INTERPRETATION

Our prognostic model, which uses easily accessible clinical features can discriminate between type 1 diabetes patients who have a good or a poor prognosis. Such a prognostic model may be helpful in clinical practice and for risk stratification in clinical trials.

Fibrin clot properties and haemostatic function in men and women with type 1 diabetes

The increased risk of vascular complications in type 1 diabetes may in part be explained by changes in haemostatic function. In the present study, we investigated the fibrin clot properties in patients with type 1 diabetes in relation to sex and microvascular complications. The study included 236 patients (107 women) aged between 20-70 years and without any history of cardiovascular disease. Fibrin clot properties, assessed by determination of the permeability coefficient (Ks) and turbidimetric clotting and lysis assays, did not differ between men and women. Compared with men, women had worse glycaemic control as well as higher levels of prothrombin fragment 1+2 and peak thrombin generation in vitro, indicating increased thrombin generation both in vivo and in vitro. Subgroup analyses of patients younger than 30 years revealed less permeable fibrin clots and prolonged lysis time in females compared with age-matched men. Patients with microvascular complications had higher fibrinogen concentrations and denser and less permeable fibrin clots. Thus, we conclude that in vitro fibrin clot properties in patients with type 1 diabetes without cardiovascular disease are not different between the sexes, but associate with prevalence of microvascular complications. Tighter fibrin clot formation in younger women, as suggested by our results, may affect their future cardiovascular risk and should be investigated in a larger population.

Body mass index and retinopathy in type 1 diabetic patients

Aim. To investigate whether body mass index (BMI) independently or in correlation with other risk factors is associated with diabetic retinopathy (DR) progression. Methods. The study included 176 patients with type 1 diabetes divided into three groups according to DR status: group 1 (no retinopathy; n = 86), group 2 (mild/moderate nonproliferative DR; n = 33), and group 3 (severe/very severe NPDR or proliferative DR; n = 57). Results. A significant deterioration of HbA1c, an increase in total cholesterol, systolic, diastolic blood pressure, and diabetic nephropathy with the progression of retinopathy were found. DR progression was correlated with diabetes duration, HbA1c, hypertension, total cholesterol, and the presence of nephropathy. In patients without nephropathy, statistical analyses showed that progression of retinopathy increased significantly with higher BMI (gr. 1: 24.03 ± 3.52, gr. 2: 25.36 ± 3.44, gr. 3: 26.93 ± 3.24; P < 0.01). A positive correlation between BMI and a significant deterioration of HbA1c, an increase in cholesterol, triglycerides, and hypertension was observed. Conclusion. BMI in correlation with HbA1c, cholesterol, and hypertension appears to be associated with the progression of DR in type 1 diabetic patients without nephropathy. However, additional studies are required to investigate the pathogenic role of obesity and weight loss in retinal diabetic complications particularly relating to nephropathy.

Associations and interactions between lipid profiles, retinopathy and nephropathy in patients with type 1 diabetes: the FinnDiane Study

OBJECTIVES

The aim of this study was to investigate the associations between lipid profiles and retinopathy in the large nationwide FinnDiane Study and to examine interactions and correlations between retinopathy, nephropathy and lipid variables.

DESIGN AND SUBJECTS

A total of 1465 patients with type 1 diabetes, available lipid profiles, ophthalmic records and fundus photographs were included in the study. The Early Treatment of Diabetic Retinopathy Study scale was used to assess the severity of retinopathy. In an independent cohort of 1100 patients, laser treatment was used to define severe diabetic retinopathy.

RESULTS

HDL cholesterol was associated with proliferative retinopathy (PDR), and triglycerides were associated with mild nonproliferative retinopathy (NPDR) independently of nephropathy and other conventional risk factors (P < 0.01). Significant interactions were seen between albumin excretion rate (AER), retinopathy status and lipid parameters (including triglycerides, non-HDL cholesterol and apolipoprotein B; P < 0.001). Highly different correlations between AER and lipid variables were observed in patients without retinopathy or with mild NPDR compared with patients with moderate to severe NPDR or PDR. Similar interactions and correlations were observed in an independent cohort stratified by laser treatment. In patients without retinopathy or with mild NPDR, AER was low despite HDL cholesterol in the lowest or triglycerides, total cholesterol or LDL cholesterol in the highest quartiles.

CONCLUSIONS

Nephropathy had a strong effect on the associations between lipid variables and retinopathy, whilst dyslipidaemia was associated with nephropathy only in the presence of retinopathy. This finding suggests the existence of shared pathogenic mechanisms between retinopathy and nephropathy which could be targeted to prevent complications in patients with metabolic risk factors.

Baseline central macular thickness predicts the need for retreatment with intravitreal triamcinolone plus laser photocoagulation for diabetic macular edema

Purpose

To identify baseline characteristics that predict the number of treatments with intravitreal triamcinolone acetonide (IVTA) plus laser photocoagulation needed to treat diabetic macular edema over a 2-year period.

Methods

Individual data from 42 eyes of 42 participants treated with IVTA plus laser photocoagulation for diabetic macular edema during a prospective, randomized, double-masked, placebo-controlled trial were used for this post hoc analysis. Baseline characteristics – age, gender, best-corrected visual acuity, glycosylated hemoglobin, phakic status, intraocular pressure, and central macular thickness (CMT) – were correlated with the number of IVTA plus laser treatments received during the 2 years of this study.

Results

The median number of treatments received over the 2-year period was 2.5 (interquartile range 1.0–3.0), with 21 (50%) eyes needing three or more treatments. Eyes that received more IVTA plus laser treatments had a higher mean baseline CMT and eyes with a higher baseline CMT were more likely to receive three or more treatments (odds ratio 5.13, 95% confidence interval 1.75–15.04, P=0.003 per 100 μm increase in CMT). No significant relationship was found between other baseline characteristics and the number of IVTA plus laser treatments received.

Conclusion

Higher baseline CMT was strongly linked with receiving more IVTA plus laser treatments. These patients may be at higher risk of developing dose-dependent steroid-related adverse events, cataract progression, and intraocular pressure rise.

Effect of an educational intervention in primary care physicians on the compliance of indicators of good clinical practice in the treatment of type 2 diabetes mellitus [OBTEDIGA project]

AIM

To evaluate the effect of an educational intervention among primary care physicians on several indicators of good clinical practice in diabetes care.

METHODS

Two groups of physicians were randomly assigned to the intervention or control group (IG and CG). Every physician randomly selected two samples of patients from all type 2 diabetic patients aged 40 years and above and diagnosed more than a year ago. Baseline and final information were collected cross-sectionally 12 months apart, in two independent samples of 30 patients per physician. The educational intervention comprised: distribution of educational materials and physicians' specific bench-marking information, an on-line course and three on-site educational workshops on diabetes. External observers collected information directly from the physicians and from the medical records of the patients on personal and family history of disease and on the evolution and treatment of their disease. Baseline information was collected retrospectively in the control group.

RESULTS

Intervention group comprised 53 physicians who included a total of 3018 patients in the baseline and final evaluations. CG comprised 50 physicians who included 2868 patients in the same evaluations. Measurement of micro-albuminuria in the last 12 months (OR = 1.6, 95% CI: 1.1-2.4) and foot examination in the last year (OR = 2.0, 95% CI: 1.1-3.6) were the indicators for which greater improvement was found in the IG. No other indicator considered showed statistically significant improvement between groups.

CONCLUSIONS

The identification of indicators with very low level of compliance and the implementation of a simple intervention in physicians to correct them is effective in improving the quality of care of diabetic patients.

Skin autofluorescence is associated with past glycaemic control and complications in type 1 diabetes mellitus

As skin autofluorescence (AF) can assess subcutaneous accumulation of fluorescent advanced glycation end-products (AGEs), this study aimed to investigate whether it was linked to glycaemic control and complications in patients with type 1 diabetes mellitus (T1DM). Using the AGE Reader™, AF was measured in T1DM patients referred to Haut-Levêque Hospital (Bordeaux, France); data on their HbA1c levels measured every 6months as far back as the last 5years were also collected. The association of AF with the patients' past glucose control, based on their latest HbA1c values, and the means of the last five and 10 HbA1c values, and with diabetic complications was also examined by linear regression analysis. The sample included 300 patients: 58% were male; the mean age was 49 (SD 17) years and the mean diabetes duration was 21 (SD 13) years. The median skin AF measurement was 2.0 [25th-75th percentiles: 1.7-2.4] arbitrary units (AU), and this was associated with age (β=0.15 per 10years, P<0.001) and diabetes duration (β=0.17 per 10years, P<0.001). After adjusting for age and estimated glomerular filtration rate (eGFR), the skin AF measurement was also related to the means of the last five and 10 HbA1c values (β=0.10 per 1% of HbA1c, P=0.005, and β=0.13 per 1% of HbA1c, P=0.001, respectively). In addition, the skin AF was associated with retinopathy (P<0.001), albuminuria (P<0.001) and decreased eGFR (P<0.001). In conclusion, the skin AF is related to the long-term glucose control and diabetic complications.

Risk of cardiovascular diseases is increased even with mild diabetic retinopathy: the Japan Diabetes Complications Study

OBJECTIVE

Diabetic retinopathy (DR) is linked to cardiovascular risk in diabetic patients. This study examined whether mild-stage DR is associated with risk of coronary heart disease (CHD) and stroke in type 2 diabetic patients of the Japan Diabetes Complications Study (JDCS).

DESIGN

Prospective cohort study.

PARTICIPANTS

In the JDCS, there were 2033 Japanese persons with type 2 diabetes free of cardiovascular diseases at baseline.

METHODS

Diabetic retinopathy was ascertained from clinical and photographic grading (70%) following the international clinical diabetic retinopathy and diabetic macular edema disease severity scales. Incident CHD and stroke were followed up prospectively annually up to 8 years.

MAIN OUTCOME MEASURES

Eight-year incidence of CHD and stroke compared between persons with or without DR.

RESULTS

After adjusting for traditional cardiovascular risk factors, persons with mild to moderate nonproliferative DR had a higher risk of CHD (hazard ratio [HR], 1.69; 95% confidence interval [CI], 1.17-2.97) and stroke (HR, 2.69; 95% CI, 1.03-4.86). Presence of retinal hemorrhages or microaneurysms was associated with risk of CHD (HR, 1.63; 95% CI, 1.04-2.56) but was not associated with stroke (P = 0.06). Presence of cotton-wool spots was associated with risk of incident stroke (HR, 2.39; 95% CI, 1.35-4.24) but was not associated with CHD (P = 0.66). When information about DR was added in the prediction models for CHD and stroke based on traditional cardiovascular risk factors, the area under the receiver operating curve improved from 0.682 to 0.692 and 0.640 to 0.677, and 9% and 13% of persons were reclassified correctly for CHD and stroke, respectively.

CONCLUSIONS

Type 2 diabetic patients with even a mild stage of DR, such as dot hemorrhages, are already at higher risk of CHD and stroke independent of traditional risk factors.

Prevalence of diabetic retinopathy in Norway: report from a screening study

PURPOSE

The purpose of the present study was to investigate the prevalence of diabetic retinopathy (DR) in Norway and adherence to the Norwegian Guidelines for screening for diabetic eye disease.

METHODS

Two hundred and ninety-nine people with diabetes were randomly recruited from the patient lists of randomly selected general practitioners from three different regions in Norway. Retinopathy was evaluated from retinal photographs after dilation of the pupils using a red-free digital camera and visual acuity was measured using the Snellen chart. The patients were interviewed about their ophthalmological and general diabetes control, duration and type of diabetes and medical treatment.

RESULTS

The prevalence of any DR was 28%, 66% for type 1 and 24% for type 2 diabetes. The prevalence of proliferative retinopathy was 38% in type 1 and 1.5% in type 2 diabetes. Two patients (one type 1 and one insulin-treated type 2) were visually impaired (visual acuity 0.3 or worse in the better eye) because of proliferative DR. Twenty-six per cent of the patients had never been to an eye examination, and only 69% attended routine eye examinations. Patients who did not attend regular eye screenings were mostly people with type 2 diabetes.

CONCLUSION

The prevalence of DR was higher than previously reported in Norway. Screening for DR did not follow guidelines in a considerable proportion of the patients with type 2 diabetes. There is place for improvement in the implementation of guidelines for screening for DR for people with type 2 diabetes in Norway.

Association of angiotensin-converting enzyme gene 2350 G/A polymorphism with diabetic retinopathy in Chinese Han population

The angiotensin-converting enzyme (ACE) gene is one of the most studied candidate genes related to diabetic retinopathy (DR). ACE 2350 G/A polymorphism (rs4343) is known among the polymorphisms of this gene to have the most significant effect on plasma ACE concentrations. The aim of the present study was to investigate the relationship between 2350 G/A polymorphism of ACE gene and the susceptibility of DR in Chinese Han population. A case-control study for 145 type 2 diabetes mellitus (DM) patients, including 63 type 2 DM without DR (NDR) and 82 type 2 DM with DR (DR), and 90 subjects of age, gender matched normal controls (NC group) was performed. ACE 2350 G/A genotypes were identified by polymerase chain reaction and restriction digestion in all study participants. The distribution of the ACE 2350 G/A genotypes (GG, GA, and AA) was 35.56, 45.55, and 18.89 % in the NC group, 28.57, 46.03, and 25.40 % in the NDR group, and 15.85, 46.34, and 37.81 % in the DR group, respectively. There were no significant differences in either genotype frequency distribution (P = 0.5266) or allele frequency distribution (P = 0.2425) between the NC group and NDR group. However, the distribution of genotype frequency (P = 0.0026) and allele frequency (P = 0.0003) in the DR group showed a significant difference when compared to that of NC group (P = 0.0075). Moreover, there was statistical difference in allele frequency distribution (P = 0.0328) between the DR group and the NDR group. No statistical differences were observed between ACE 2350 G/A polymorphism and the diabetes duration or types of DR. Results obtained in this study indicate that ACE 2350 G/A polymorphism is associated with DR in Han Chinese patients with type 2 DM.

Osmotic stress induced oxidative damage: possible mechanism of cataract formation in diabetes

Chronic hyperglycemia causes increased level of reactive oxygen species which is thought to be involved in the pathogenesis of diabetes associated complications including cataract. In diabetic cataractous lens, over production of free radicals and decreased capacity of antioxidant defense system are the major contributors to oxidative damage by polyol pathway and advanced glycation end products. The current study focused on analysis of factors associated with osmotic imbalance and oxidative stress in aging and diabetic human cataractous lenses. We examined activities of polyol pathway enzymes, G6PD and glutathione system in lenses from subjects suffering from cataract due to aging and diabetes. We observed elevated activities of aldose reductase and sorbitol dehydrogenase while G6PD and glutathione system enzyme activities were found to be lower in cataractous subjects suffering from diabetes. The findings from the current study support the premise that osmotic imbalance, AGEs formation and oxidative stress contribute synergistically to the development of lens opacity in hyperglycemia.

Causes of visual disability among Central Africans with diabetes mellitus

BACKGROUND

Diabetic Retinopathy (DR) remains a common and one of the major causes of blindness in the developed and western societies. The same situation is shown in emerging economic areas (5,6). In sub-Saharan Africa (SSA) however, the issues of visual disability due to diabetes mellitus (DM) are overshadowed by the presence of the prevalent and common nutritional deficiency diseases and eye infections

OBJECTIVE

This clinic-based study was conducted to determine whether diabetic retinopathy is independently related to visual disability in black patients with diabetes mellitus (DM) from Kinshasa, Congo.

METHODS

A total of 299 urban patients with DM and low income including 108 cases of visual disability and matched for time admission and DM type to 191 controls, were assessed. Demographic, clinical, and ophthalmic data were assessed using univariate and multivariate analyses.

RESULTS

Age ≥60 years, female sex, presence of diabetic retinopathy (DR), proliferative DR, shorter DM duration, glaucoma, macular oedema, diabetic nephropathy were the univariate risk factors of visual disability. Using logistic regression model, visual disability was significantly associated with female sex and diabetic retinopathy.

CONCLUSION

The risk of visual disability is 4 times higher in patients with diabetic retinopathy and 2 times higher in females with DM. Therefore, to prevent further increase of visual disability, the Congolese Ministry of Health should prioritize the eye care in patients with DM.

Cross-sectional associations of blood elements, clotting factors, nephropathy, and retinal outcomes in long duration type 1 diabetes

PURPOSE

To determine the association of blood elements, selected clotting factors, and nephropathy with proliferative diabetic retinopathy (PDR) and macular edema (ME) in those with long duration type 1 diabetes.

METHODS

Participants (N = 442) were seen in 2005-2007 at the 25-year follow-up of a population-based study of diabetic retinopathy, and were eligible for this analysis. Fundus photographs were graded using a standard retinopathy severity scheme. Laboratory measures included hematocrit, white blood cell and platelet counts, serum fibrinogen, interleukin-6, and von Willebrand factor.

RESULTS

In models including duration of diabetes, hypertension, and diabetic nephropathy, only hematocrit was marginally associated with decreased odds of PDR (odds ratio 0.87; 95% confidence interval 0.74-1.01; P for trend per quintile = 0.06). Stratifying by nephropathy status, in those with and without nephropathy, there were no significant associations of any laboratory measures with PDR or ME. None of the variables we examined were associated with ME in individuals with or without nephropathy.

CONCLUSION

In persons with long duration type 1 diabetes, none of the blood elements or clotting factors were associated with increased odds of PDR or ME. Investigation of common pathways that lead to diabetic nephropathy and diabetic retinal outcomes should be a research priority in efforts to prevent vision-threatening complications of diabetes and nephropathy.

A(₂A) adenosine receptor (A(₂A)AR) as a therapeutic target in diabetic retinopathy

In diabetic retinopathy (DR), abnormalities in vascular and neuronal function are closely related to the local production of inflammatory mediators whose potential source is microglia. A(₂A) adenosine receptor (A(₂A)AR) has been shown to possess anti-inflammatory properties that have not been studied in DR. Here, we evaluate the role of A(₂A)AR and its underlying signaling in retinal complications associated with diabetes. Initial studies in wild-type mice revealed that the treatment with the A(₂A)AR agonist resulted in marked decreases in hyperglycemia-induced retinal cell death and tumor necrosis factor (TNF)-α release. To further assess the role of A(₂A)AR in DR, we studied the effects of A(₂A)AR ablation on diabetes-induced retinal abnormalities. Diabetic A(₂A)AR(-/-) mice had significantly more terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cells, TNF-α release, and intercellular adhesion molecule-1 expression compared with diabetic wild-type mice. To explore a potential mechanism by which A(₂A)AR signaling regulates inflammation in DR, we performed additional studies using microglial cells treated with Amadori-glycated albumin, a risk factor in diabetic disorders. The results showed that activation of A(₂A)AR attenuated Amadori-glycated albumin-induced TNF-α release in a cAMP/exchange protein directly activated by cAMP-dependent mechanism and significantly repressed the inflammatory cascade, C-Raf/extracellular signal-regulated kinase (ERK), in activated microglia. Collectively, this work provides pharmacological and genetic evidence for A(₂A)AR signaling as a control point of cell death in DR and suggests that the retinal protective effect of A(2A)AR is mediated by abrogating the inflammatory response that occurs in microglia via interaction with C-Raf/ERK pathway.

Diabetic retinopathy in type 1 diabetes-a contemporary analysis of 8,784 patients

AIMS/HYPOTHESIS

The aim of this study was to analyse the risk profile for diabetic retinopathy under real-life conditions in a large cohort of patients with type 1 diabetes.

METHODS

Patients (n = 18,891) with childhood, adolescent or adult onset of type 1 diabetes from the prospective German Diabetes Documentation System survey were analysed. A total of 8,784 patients fulfilled the inclusion criterion, which was availability of retinopathy status. Retinopathy grading (any retinopathy, advanced retinopathy), treatment regimens and risk factors were prospectively recorded and tested as covariates by Kaplan-Meier analysis and logistic regression.

RESULTS

Any retinopathy was present in 27.4% and advanced retinopathy (severe non-proliferative or proliferative diabetic retinopathy) in 8.0% of the cohort. After 40 years of diabetes, the cumulative proportion of patients with any retinopathy and advanced retinopathy was 84.1% and 50.2%, respectively. In multiple regression analysis, risk factors for any retinopathy were diabetes duration (OR 1.167 per year), HbA(1c) >7.0% (53 mmol/mol) (OR 2.225), smoking (OR 1.295) and male sex (OR 1.187) (p < 0.0001 for all). Young age at onset (5 vs 15 years at disease onset) was protective (0.410, p < 0.0001). No glycaemic threshold was detected for retinopathy protection. Risk factors for advanced retinopathy were duration (1.124 per year, p < 0.0001), male sex (1.323, p = 0.0020), HbA(1c) >7.0% (53 mmol/mol) (1.499, p < 0.0001), triacylglycerol >1.7 mmol/l (1.398, p = 0.0013) and blood pressure  >140/90 mmHg (1.911, p < 0.0001).

CONCLUSIONS/INTERPRETATION

The prevalence of retinopathy remains significant in type 1 diabetes. Any improvement of metabolic control and non-smoking is protective, while hypertension affects progression to severe levels under real-life conditions. These data reinforce the validity of multifactorial concepts for morbidity protection in type 1 diabetes.

PPARgamma Agonists: Potential as Therapeutics for Neovascular Retinopathies

The angiogenic, neovascular proliferative retinopathies, proliferative diabetic retinopathy (PDR), and age-dependent macular degeneration (AMD) complicated by choroidal neovascularization (CNV), also termed exudative or “wet” AMD, are common causes of blindness. The antidiabetic thiazolidinediones (TZDs), rosiglitazone, and troglitazone are PPARγ agonists with demonstrable antiproliferative, and anti-inflammatory effects, in vivo, were shown to ameliorate PDR and CNV in rodent models, implying the potential efficacy of TZDs for treating proliferative retinopathies in humans. Activation of the angiotensin II type 1 receptor (AT1-R) propagates proinflammatory and proliferative pathogenic determinants underlying PDR and CNV. The antihypertensive dual AT1-R blocker (ARB), telmisartan, recently was shown to activate PPARγ and improve glucose and lipid metabolism and to clinically improve PDR and CNV in rodent models. Therefore, the TZDs and telmisartan, clinically approved antidiabetic and antihypertensive drugs, respectively, may be efficacious for treating and attenuating PDR and CNV humans. Clinical trials are needed to test these possibilities.