The prevalence of diabetic retinopathy in patients with screen-detected type 2 diabetes in Denmark: the ADDITION study

Nuclear proteins and diabetic retinopathy: a review

Diabetic retinopathy (DR) is an eye disease that causes blindness and vision loss in diabetic. Risk factors for DR include high blood glucose levels and some environmental factors. The pathogenesis is based on inflammation caused by interferon and other nuclear proteins. This review article provides an overview of DR and discusses the role of nuclear proteins in the pathogenesis of the disease. Some core proteins such as MAPK, transcription co-factors, transcription co-activators, and others are part of this review. In addition, some current advanced treatment resulting from the role of nuclear proteins will be analyzes, including epigenetic modifications, the use of methylation, acetylation, and histone modifications. Stem cell technology and the use of nanobiotechnology are proposed as promising approaches for a more effective treatment of DR.

Extending the diabetic retinopathy screening intervals in Singapore: methodology and preliminary findings of a cohort study

BACKGROUND

The Diabetic Retinopathy Extended Screening Study (DRESS) aims to develop and validate a new DR/diabetic macular edema (DME) risk stratification model in patients with Type 2 diabetes (DM) to identify low-risk groups who can be safely assigned to biennial or triennial screening intervals. We describe the study methodology, participants' baseline characteristics, and preliminary DR progression rates at the first annual follow-up.

METHODS

DRESS is a 3-year ongoing longitudinal study of patients with T2DM and no or mild non-proliferative DR (NPDR, non-referable) who underwent teleophthalmic screening under the Singapore integrated Diabetic Retinopathy Programme (SiDRP) at four SingHealth Polyclinics. Patients with referable DR/DME (> mild NPDR) or ungradable fundus images were excluded. Sociodemographic, lifestyle, medical and clinical information was obtained from medical records and interviewer-administered questionnaires at baseline. These data are extracted from medical records at 12, 24 and 36 months post-enrollment. Baseline descriptive characteristics stratified by DR severity at baseline and rates of progression to referable DR at 12-month follow-up were calculated.

RESULTS

Of 5,840 eligible patients, 78.3% (n = 4,570, median [interquartile range [IQR] age 61.0 [55-67] years; 54.7% male; 68.0% Chinese) completed the baseline assessment. At baseline, 97.4% and 2.6% had none and mild NPDR (worse eye), respectively. Most participants had hypertension (79.2%) and dyslipidemia (92.8%); and almost half were obese (43.4%, BMI ≥ 27.5 kg/m2). Participants without DR (vs mild DR) reported shorter DM duration, and had lower haemoglobin A1c, triglycerides and urine albumin/creatinine ratio (all p < 0.05). To date, we have extracted 41.8% (n = 1909) of the 12-month follow-up data. Of these, 99.7% (n = 1,904) did not progress to referable DR. Those who progressed to referable DR status (0.3%) had no DR at baseline.

CONCLUSIONS

In our prospective study of patients with T2DM and non-referable DR attending polyclinics, we found extremely low annual DR progression rates. These preliminary results suggest that extending screening intervals beyond 12 months may be viable and safe for most participants, although our 3-year follow up data are needed to substantiate this claim and develop the risk stratification model to identify low-risk patients with T2DM who can be assigned biennial or triennial screening intervals.

Sex-Related Effects of Gut Microbiota in Metabolic Syndrome-Related Diabetic Retinopathy

The metabolic syndrome (MetS) is a complex disease of metabolic abnormalities, including obesity, insulin resistance, hypertension and dyslipidaemia, and it is associated with an increased risk of cardiovascular disease (CVD). Diabetic retinopathy (DR) is the leading cause of vision loss among working-aged adults around the world and is the most frequent complication in type 2 diabetic (T2D) patients. The gut microbiota are a complex ecosystem made up of more than 100 trillion of microbial cells and their composition and diversity have been identified as potential risk factors for the development of several metabolic disorders, including MetS, T2D, DR and CVD. Biomarkers are used to monitor or analyse biological processes, therapeutic responses, as well as for the early detection of pathogenic disorders. Here, we discuss molecular mechanisms underlying MetS, the effects of biological sex in MetS-related DR and gut microbiota, as well as the latest advances in biomarker research in the field. We conclude that sex may play an important role in gut microbiota influencing MetS-related DR.

Bidirectional 5-year risks of diabetic retinopathy, glaucoma and/or ocular hypertension: Results from a national screening programme

PURPOSE

We aimed to investigate if diabetic retinopathy (DR), glaucoma and/or ocular hypertension (OHT) are prospectively linked, as previous studies have proposed cross-sectional associations, but longitudinal data from larger cohorts are lacking.

METHODS

We performed a bidirectional 5 years prospective, registry-based cohort study. We extracted data from national registers, including the Danish Registry of Diabetic Retinopathy, the Danish Civil Registration System, the Danish National Patient Register and the Danish National Prescription Registry. DR level was defined by the highest level of the two eyes. Glaucoma and/or OHT was defined by diagnostic codes (H40*) or at least three redeemed prescriptions of glaucoma medication (S01E*) within 1 year. We included 205 970 persons with diabetes and 1 003 170 age- and gender-matched non-diabetes controls. Exposures were level-specific DR (i) and glaucoma and/or OHT (ii), and outcomes were hazard ratios (HRs) for 5 years incident glaucoma and/or OHT (i) and DR (ii).

RESULTS

Persons with diabetes were more likely to develop glaucoma and/or OHT (multivariable adjusted HR 1.11, 95% CI 1.06-1.15), but this did not depend on the level of DR. In persons with diabetes, those with glaucoma and/or OHT were more likely to develop DR (multivariable adjusted HR 1.12, 95% CI 1.03-1.23) within 5 years.

CONCLUSION

In a national cohort, diabetes associated with a little higher risk of upcoming glaucoma and/or OHT, and, inversely, the presence of the latter predicted a higher risk of incident DR. Nevertheless, our data do not seem to justify including glaucoma evaluation in the national Danish DR-screening programme.

Prevalence and incidence of diabetic retinopathy (DR) in the UK population of Gloucestershire

Purpose

To estimate prevalence and incidence of diabetic retinopathy (DR) in a UK region by severity between 2012 and 2016 and risk factors for progression to proliferative DR (PDR).

Methods

Electronic medical records from people with diabetes (PWD) ≥18 years seen at the Gloucestershire Diabetic Eye Screening Programme (GDESP) and the hospital eye clinic were analysed (HEC). Prevalence and incidence of DR per 100 PWD (%) by calendar year, grade and diabetes type were estimated using log‐linear regression. Progression to PDR and associated risk factors were estimated using parametric survival analyses.

Results

Across the study period, 35 873 PWD had at least one DR assessment. They were aged 66 (56–75) years (median (interquartile range)), 57% male, 5 (1–10) years since diabetes diagnosis, 93% Type 2 diabetes. Prevalence of DR decreased from 38.9% (95% CI: 38.1%, 39.8%) in 2012 to 36.6% (95% CI: 35.9%, 37.3%) in 2016 (p < 0.001). Incidence of any DR decreased from 10.9% (95% CI: 10.4%, 11.5%) in 2013 to 8.5% (95% CI: 8.1%, 9.0%) in 2016 (p < 0.001). Prevalence of PDR decreased from 3.5% (95% CI: 3.3%, 3.8%) in 2012 to 3.1% (95% CI 2.9%, 3.3%) in 2016 (p = 0.008). Incidence of PDR did not change over time. HbA_1c and bilateral moderate–severe NPDR were statistically significant risk factors associated with progression to PDR.

Conclusions

Incidence and prevalence of DR decreased between 2012 and 2016 in this well‐characterized population of the UK.

Prevalence of microvascular and macrovascular complications of diabetes in newly diagnosed type 2 diabetes in low-and-middle-income countries: A systematic review and meta-analysis

There is an excessive burden of diabetes complications in low-resource settings. We conducted a systematic review to determine the nature and frequency of diabetes complications in newly diagnosed with type 2 diabetes. A systematic search was performed using Medline, CINAHL and Global Health online databases from inception to July 2020. Articles reporting prevalence of microvascular or macrovascular complications within six months of type 2 diabetes diagnosis and published in English or French from low- and middle-income countries (LMICs) were eligible for analysis. Data were extracted using a standardized data extraction tool. Descriptive statistics were used to describe the prevalence of micro and macrovascular complications in newly diagnosed type 2 diabetes. Assessment of heterogeneity was conducted using the inconsistency index (I2) and Cochran-Q chi2 statistical tests. Publication bias was assessed by the Funnel plot and Egger test. A total of 3 292 records underwent title or abstract screening and 95 articles underwent full text review. Thirty-three studies describing 13 283 participants (aged 20 years and older) met the inclusion criteria. The eligible studies were from Asia (n = 24), Africa (n = 4), Oceania (n = 2), South America (n = 2) and the Caribbean (n = 1). For microvascular complications, the median prevalence (interquartile range) of retinopathy, nephropathy and neuropathy were 12% (6%-15%), 15% (7%-35%) and 16% (10%25%) respectively. For macrovascular complications, the median prevalence (interquartile range) was 10% (7%-17%) for ischaemic heart disease, 6% (1%-20%) for peripheral arterial disease and 2% (1%-4%) for stroke. There was evidence of substantial heterogeneity between studies for all outcomes (I2 > 90%. We found a high prevalence of complications in newly diagnosed type 2 diabetes in LMICs. Findings suggest that many people live with diabetes and are only diagnosed when they present with complications in LMICs. Research is needed to guide timely and effective identification of people living with diabetes in these settings.

Screening for Diabetes and Prediabetes

Overt type 2 diabetes mellitus (T2DM) is preceded by prediabetes and latent diabetes (lasts 9-12 years). Key dysglycemia screening tests are fasting plasma glucose and hemoglobin A1C. Screen-detected T2DM benefits from multifactorial management of cardiovascular risk beyond glycemia. Prediabetes is best addressed by lifestyle modification, with the goal of preventing T2DM. Although there is no trial evidence of prediabetes/T2DM screening effectiveness, simulations suggest that clinic-based opportunistic screening of high-risk individuals is cost-effective. The most rigorous extant recommendations are those of the American Diabetes Association and US Preventive Services Task Force, which advise opportunistic 3-yearly screening.

Glycated hemoglobin A1C level and the risk of diabetic retinopathy in Africa: A systematic review and meta-analysis

BACKGROUND AND AIMS

Diabetic retinopathy is a frequent cause of acquired blindness worldwide. Various studies have reported the effects of glycemic control on the risk of diabetic retinopathy, but the results remain inconclusive. Therefore, this meta-analysis was performed to determine the association between glycated hemoglobin A1C levels and diabetic retinopathy in Africa.

METHODS

A systematic search was performed using the PubMed, African Journals Online, Google Scholar, Scopus, and Wiley Online Library from inception to June 11, 2020, for observational studies addressing the association of hemoglobin A1c levels with diabetic retinopathy. The I² statistic was used to check heterogeneity across the included studies. A random-effects model was applied to estimate the pooled effect size (OR) and respective 95% confidence interval across studies. A funnel plot and Egger's regression test were used to determine the presence of publication bias. Sensitivity analysis was used to determine the effect of a single study on the overall estimation. All statistical analyses were performed using STATA™ Version 14 software.

RESULT

A total of 23 articles with 18,099 study participants were included in this meta-analysis. In the present review, when HbA1c was analyzed as a categorical variable, poor glycemic control (HbA1c >7%) was associated with an increased risk of diabetic retinopathy when compared with good glycemic control (OR = 1.25; 95% CI; 1.14, 1.38). Similarly, when HbA1c was analyzed as a continuous variable, a higher HbA1c was associated with an increased risk of diabetic retinopathy (MD: 0.42, 95% CI; 0.11, 0.98).

CONCLUSION

Our meta-analysis indicated evidence for poor glycemic control as an independent risk factor for the development of diabetic retinopathy in patients with diabetes mellitus. Therefore, the authors suggest that clinicians should advise their patients with diabetes to maintain their HbA1c levels within the normal range.

Prevalence, Incidence and Ecological Determinants of Diabetic Retinopathy in Iran: Systematic Review and Meta-analysis

Purpose

To estimate the pooled prevalence and incidence of diabetic retinopathy (DR) in Iran and to investigate their correlations with the Human Development Index (HDI), healthcare access (i.e., density of specialists and sub-specialists), and methodological issues.

Methods

Electronic databases such as PubMed, Embase, Scopus, Web of Science, Google Scholar, and local databases were searched for cohort and cross-sectional studies published prior to January 2018. Prevalence and incidence rates of DR were extracted from January 2000 to December 2017 and random effects models were used to estimate pooled effect sizes. The Joanna Briggs Institute critical appraisal tool was applied for quality assessment of eligible studies.

Results

A total of 55,445 participants across 33 studies were included. The pooled prevalence (95% CI) of DR in diabetic clinics (22 studies), eye clinics (4 studies), and general population (7 studies) was 31.8% (24.5 to 39.2), 57.8% (50.2 to 65.3), and 29.6% (22.6 to 36.5), respectively. It was 7.4% (3.9 to 10.8) for proliferative DR and 7.1% (4.9 to 9.4) for clinically significant macular edema. The heterogeneity of individual estimates of prevalence was highly significant. HDI (P < 0.001), density of specialists (P = 0.004), subspecialists (P < 0.001), and sampling site (P = 0.041) were associated with heterogeneity after the adjustment for type of DR, duration of diabetes, study year, and proportion of diabetics with controlled HbA1C.

Conclusion

Human development and healthcare access were correlated with the prevalence of DR. Data were scarce on the prevalence of DR in less developed provinces. Participant recruitment in eye clinics might overestimate the prevalence of DR.

Relationship Between Hematological Parameters and Glycemic Control in Type 2 Diabetes Mellitus Patients

BACKGROUND

Diabetes mellitus (DM) with its micro- and macrocomplications is the leading global epidemic of the 21st century. The aim of the research is to determine possible changes in the complete blood count (CBC) parameters depending on glycemic controlin patients with Type 2 diabetes mellitus (T2DM).

METHODS

The study included a total of 178 patients with T2DM, both gender over the age of 40 years, from the Health Care Center »Dr Milorad Mika Pavlović« Indjija, Serbia. To notice the possible correlation between the CBC parameters and glucose control in T2DM, the subjects were divided in two groups with HbA1c ≤ 7% and with HbA1c>7%. We analysed CBC parameters, parameters of glycoregulation, lipid status using standard biochemical methods, performed anthropometric measurements and collected patients data by questionnaire and electronic patient card.

RESULTS

There was statistical difference between HbA1c groups for PMDW (p=0.045), HDL (p=0.0067). Using univariate linear regression it is shown that PCT was correlated with WBC (p=0.0005), neutrophils (p=0.046), monocytes (p=0.003); MPM was associated with MPV (p=0.0005); MPC (p=0.0005), PDW (P=0.0005), GLU0 (p=0.034), HDL-C (p=0.005); PMDW was correlated with HbA1c% (p=0.049), GLU0 (p=0.013), HDL-C (p=0.001), BW (p=0.043) in all patients.

CONCLUSIONS

Based on our study results it may be concluded that some of the parameters of CBC could be useful tool in following glycemic control of diabetics.

Prevalence and associated risk factors of undercorrected refractive errors among people with diabetes in Shanghai

Background

To investigate the prevalence and risk factors of undercorrected refractive error (URE) among people with diabetes in the Baoshan District of Shanghai, where data for undercorrected refractive error are limited.

Methods

The study was a population-based survey of 649 persons (aged 60 years or older) with diabetes in Baoshan, Shanghai in 2009. One copy of the questionnaire was completed for each subject. Examinations included a standardized refraction and measurement of presenting and best-corrected visual acuity (BCVA), tonometry, slit lamp biomicroscopy, and fundus photography.

Results

The calculated age-standardized prevalence rate of URE was 16.63% (95% confidence interval [CI] 13.76–19.49). For visual impairment subjects (presenting vision worse than 20/40 in the better eye), the prevalence of URE was up to 61.11%, and 75.93% of subjects could achieve visual acuity improvement by at least one line using appropriate spectacles. Under multiple logistic regression analysis, older age, female gender, non-farmer, increasing degree of myopia, lens opacities status, diabetic retinopathy (DR), body mass index (BMI) index lower than normal, and poor glycaemic control were associated with higher URE levels. Wearing distance eyeglasses was a protective factor for URE.

Conclusion

The undercorrected refractive error in diabetic adults was high in Shanghai. Health education and regular refractive assessment are needed for diabetic adults. Persons with diabetes should be more aware that poor vision is often correctable, especially for those with risk factors.

Screening Intervals for Diabetic Retinopathy and Implications for Care

PURPOSE OF REVIEW

The purpose of this study is to review the evidence that lower risk groups who could safely be screened less frequently for sight-threatening diabetic retinopathy (DR) than annually.

RECENT FINDINGS

Data have demonstrated that people with no DR in either eye are at a low risk of progression to sight-threatening DR over a 2-year period (event rate 4.8 per 1000 person years), irrespective of whether the screening method is one-field non-mydriatic or two-field mydriatic digital photography. Low risk has been defined as no retinopathy on two consecutive screening episodes or no retinopathy on one screening episode combined with risk factor data. The risk of an extension to 2 years is less than 5 per 1000 person years in a population with a national screening programme, and the general standard of diabetes care is relatively good, whether low risk is defined as no retinopathy on two consecutive screening episodes or no retinopathy on one screening episode combined with other risk factor data. The definition used in different populations is likely to depend on the availability of data.

Risk factors for diabetic retinopathy: a case-control study

BACKGROUND

Diabetic retinopathy (DR) is the major cause of blindness among working age adults. The aim of the study was to investigate risk factors for development of DR.

METHODS

A case-control study was performed based on data from 240 individuals (80 cases and 160 controls) attending the Outpatient Specialty Clinic of the University of South Santa Catarina (UNISUL), between Mar/2010 and May/2014. Data collection occurred through review of medical charts for presence or absence of DR, determined by an ophthalmologist. Study protocol included demographic characteristics, metabolic control, diabetes mellitus (DM) profile and comorbidities. Statistical analysis used Chi square test for qualitative variables and multivariate logistic regression analysis to select independent variables (SPSS®18.0 software). Odds ratio (OR) was used as measure of association. The study was approved by research ethics committee of UNISUL.

RESULTS

Mean age of group case was 59.5 years with a slight female predominance. Gender, age, body mass index were not associated with outcome. Individuals with poor glycemic control were more likely to DR (OR 3.83; 95 % CI 1.57-9.37). It was observed a positive relationship between duration of DM and DR, with higher chances in 11-15 years of disease (OR 7.52, 95 % CI 3.03-18.68) and >15 years (OR 9.01, 95 % CI 3.58-22.66). Regarding comorbidities, only diabetic nephropathy showed higher chance for DR (OR 3.32; 95 % CI 1.62-6.79).

CONCLUSIONS

Diabetic patients after 10 years of disease with poor glycemic control and nephropathy have a higher chance of DR.

Prevalence of diabetic retinopathy in screening-detected diabetes mellitus: results from the Gutenberg Health Study (GHS)

AIMS/HYPOTHESIS

Individuals with type 2 diabetes mellitus may experience an asymptomatic period of hyperglycaemia, and complications may already be present at the time of diagnosis. We aimed to determine the prevalence of diabetic retinopathy in patients with newly diagnosed (screening-detected) type 2 diabetes.

METHODS

The Gutenberg Health Study is a population-based study with 15,010 participants aged between 35 and 74 years. We determined the weighted prevalence of diabetic retinopathy by assessing fundus photographs. Screening-detected type 2 diabetes was defined as an HbA1c concentration of 6.5% (47.5 mmol/mol) or more, no medical diagnosis of diabetes and no intake of insulin or oral glucose-lowering agents.

RESULTS

Of 14,948 participants, 1377 (9.2%) had diabetes mellitus. Of these, 347 (25.2%) had newly diagnosed type 2 diabetes detected by the screening. Overall, the weighted prevalence of screening-detected type 2 diabetes was 2.1%. Fundus photos were evaluable for 285 (82.1%) participants with newly diagnosed diabetes. The weighted prevalence of diabetic retinopathy in screening-detected type 2 diabetes was 13.0%; 12% of participants had a mild non-proliferative diabetic retinopathy and 0.6% had a moderate non-proliferative diabetic retinopathy. Diabetic retinopathy was proliferative in 0.3%. No cases of severe non-proliferative diabetic retinopathy or diabetic maculopathy were found. Thirty (14.9%) of 202 and six (7.2%) of 83 individuals with and without concomitant arterial hypertension, respectively, had diabetic retinopathy (OR 2.54, 95% CI 1.06, 7.14). Visual acuity did not differ between individuals with and without diabetic retinopathy .

CONCLUSIONS/INTERPRETATION

In this large European study, the prevalence of diabetic retinopathy in screening-detected type 2 diabetes was 13%. Only a very small proportion of participants with detected diabetic retinopathy needed treatment.

Determining the Prevalence of Retinopathy and Its Related Factors among Patients with Type 2 Diabetes in Kerman, Iran

Objectives

To determine the prevalence of retinopathy and its associated factors in diabetic patients referred to a diabetes center in an Iranian city.

Methods

This was a cross-sectional, descriptive–analytical study in which a researcher-made checklist was used to collect the data of patients with type 2 diabetes in 2015. The statistical population consisted of 11,770 health records of diabetic patients registered in a second-level diabetes center. Of the 11,770 health records, 206 records with the most complete data about patients with type 2 diabetes were selected through census method. Chi-square test and logistic regression through SPSS were used for data analysis.

Results

In this study, 93/206 diabetic patients (45.1%) had retinopathy. Female sex, age over 60, lower education level, being housewife, family history of having diabetes, longer years of having the disease, and higher level of hemoglobin A1c (HbA1c) were associated with higher risk of retinopathy. However, the association was statistically significant only for the HbA1c level (p ≥ 0.05).

Conclusion

According to this study, HbA1c level is a predictor of diabetes complications. Therefore, it is necessary for health authorities to improve diabetes management through different strategies to prevent complications to control blood sugar effectively.

Early detection of type 2 diabetes mellitus and screening for retinopathy are associated with reduced prevalence and severity of retinopathy

PURPOSE

To explore whether the prevalence and severity of retinopathy differ in diabetes cohorts diagnosed through screening as compared with conventional health care.

METHODS

A total of 257 diabetes patients, 151 detected through screening and 106 through conventional clinical care, were included. Retinopathy was evaluated by fundus photography. The modified Airlie House adaptation of the Early Treatment Retinopathy Study protocol was used to grade the photographs. Averages of clinically collected fasting blood glucose (FBG), blood pressure and body mass index values were compiled from diabetes diagnosis until the eye examination. Blood chemistry, smoking habits and peripheral neuropathy were assessed at the time of the eye examination.

RESULTS

Among the screening-detected patients, 22% had retinopathy as compared to 51% among those clinically detected (p < 0.0001). In a multivariate analysis, patients with retinopathy were more likely to have increased average FBG (OR 1.42, 95% CI 1.19-1.70 per mmol/l) and peripheral neuropathy (OR 2.75, 95% CI 1.40-5.43), but less likely to have screening-detected diabetes (OR 0.31, 95% CI 0.17-0.57). Similar results were found using increasing severity grade of retinopathy as outcome. The cumulative retinopathy prevalence for the screening-detected diabetes cohort as compared with the clinically diagnosed cohort was significantly lower from 10 years' follow-up and onwards (p = 0.0002).

CONCLUSIONS

Among patients with screening-detected diabetes, the prevalence of retinopathy and increasing severity of retinopathy were significantly lower than among those who had their diabetes diagnosed through conventional care, even when other risk factors for retinopathy such as duration, hyperglycaemia and blood pressure were considered. Early detection of diabetes reduces prediagnostic time spent with hyperglycaemia. In combination with early and regular screening for retinopathy, more effective prevention against retinopathy can be provided.

Yang Deficiency Body Constitution Acts as a Predictor of Diabetic Retinopathy in Patients with Type 2 Diabetes: Taichung Diabetic Body Constitution Study

Objective. Diabetic retinopathy (DR), the most common microvascular complication of diabetes mellitus (DM), can cause severe visual impairment and blindness. To prevent the development of DR, identifying the associated risk factors for patient classification is critical. We conducted a cross-sectional study to determine whether body constitution (BC) is an independent predictor of DR. Method. 673 type 2 DM (T2DM) patients were recruited from a medical center, all received DR examination and body constitution questionnaire to assess BC. Other risk factors for DR were also recorded, including life style, history of diabetes, and blood pressure, etc. Multiple logistic regression analysis was conducted to calculate the odds ratios (ORs) for DR. Results. The prevalence of DR was significantly lower in Yang deficiency patients compared with non-Yang deficiency patients (24.69% versus 38.18% P = 0.02). After adjusting for other risk factors, we observed that patients exhibiting Yang deficiency BC were less likely to present with DR (OR = 0.531; 95% confidence interval = 0.312-0.903, P = 0.018). Conclusion. In addition to traditional risk factors, Yang deficiency BC might be an independent predictor of DR among T2DM patients and the results can be used as evidence for traditional Chinese medicine patient classification.

Does Insulin Like Growth Factor-1 (IGF-1) Deficiency Have a "Protective" Role in the Development of Diabetic Retinopathy in Thalassamia Major Patients?

RATIONALE

Both insulin and IGF-1 have been implicated in the control of retinal endothelial cell growth, neovascularization and diabetic retinopathy. Recent findings have established an essential role for IGF-1 in angiogenesis and demonstrated a new target for control of retinopathy that explains why diabetic retinopathy initially increases with the onset of insulin treatment.

OBJECTIVE

This cross-sectional study was designed to give insights into relationship between Insulin-Growth-Factor 1 (IGF-1) levels and diabetic retinopathy (DR) in a sample of thalassemia major (TM) patients with insulin dependent diabetes mellitus (IDDM). This relation was not previously evaluated, despite the fact that both diseases co-exist in the same patient. The study also describes the clinical and biochemical profile of the associated complications in TM patients with and without IDDM.

DESIGN

A population-based cross-sectional study.

PARTICIPANTS

The study includes 19 consecutive TM patients with IDDM and 31 age- and sex-matched TM patients without IDDM who visited our out-patient clinics for an endocrine assessment.

METHODS

An extensive medical history, with data on associated complications and current medications, was obtained. Blood samples were drawn in the morning after an overnight fast to measure the serum concentrations of IGF-1, glucose, fructosamine, free thyroxine (FT4), thyrotropin (TSH) and biochemical analysis. Serologic screening assays for hepatitis C virus seropositivity (HCVab and HCV-RNA) were also evaluated; applying routine laboratory methods. Plasma total IGF-1 was measured by a chemiluminescent immunometric assay (CLIA) method. Ophthalmology evaluation was done by the same researcher using stereoscopic fundus biomicroscopy through dilated pupils. DR was graded using the scale developed by the Global Diabetic Retinopathy Group. Iron stores were assessed by direct and indirect methods.

RESULTS

Eighteen TM patients with IDDM (94.7 %) and ten non-diabetic patients (32.2 %) had IGF-1 levels below the 2.5(th) percentile of the normal values for the Italian population. The mean serum IGF-1 concentrations were significantly lower in the diabetic versus the non-diabetic TM groups (p < 0.001). DR was present in 4 (21 %) of 19 TM patients with IDDM and was associated with the main classical risk factors, namely inefficient glycemic control and duration of the disease but not hypertension. Using the scale developed by the Global Diabetic Retinopathy Group, the DR in our patients was classified as non proliferative diabetic retinopathy (NPDR). Only a few numbers of microaneurysms [1-3] were detected. Our data also confirm the strong association of IDDM in TM patients with other endocrine and non-endocrine complications.

A classification model for predicting eye disease in newly diagnosed people with type 2 diabetes

Diabetic retinopathy may be present at the time type 2 diabetes is diagnosed, and initial screening encompassing an eye examination performed by an ophthalmologist or optometrist is therefore recommended. However, proper screening for retinopathy may be challenging in many parts of the world. We hypothesized that simple, commonly available patient characteristics can be used to identify patients at high risk for having retinopathy. We investigated data from multiple years extracted from the National Health and Nutrition Examination Survey which holds information about blood glucose and eye examinations. Individuals with hitherto undiagnosed diabetes were classified according to the presence or absence of retinopathy. Linear classification was used to predict which patients had retinopathy at the time of diagnosis. A total of 266 individuals with undiagnosed diabetes were identified from the cohorts. Of these, 222 individuals had no sign of retinopathy, whereas 44 had mild or moderate non-proliferative retinopathy. Using information regarding HbA1c, BMI, waist circumference, age, systolic blood pressure, urinary albumin, and urinary creatinine, we were able to construct a model that predicts the presence of retinopathy with a positive predictive value of 22% and a negative predictive value of 99%. Only one true positive (1/44) with mild non-proliferative retinopathy was falsely classified. A classification model using readily available patient information and routine biochemical measures can be used to identify patients at high risk of having retinopathy at the time their diabetes is diagnosed. The model may be used to identify high-risk patients for retinopathy screening.

Topiramate Protects Pericytes from Glucotoxicity: Role for Mitochondrial CA VA in Cerebromicrovascular Disease in Diabetes

Hyperglycemia in diabetes mellitus causes oxidative stress and pericyte depletion from the microvasculature of the brain thus leading to the Blood-Brain Barrier (BBB) disruption. The compromised BBB exposes the brain to circulating substances, resulting in neurotoxicity and neuronal cell death. The decline in pericyte numbers in diabetic mouse brain and pericyte apoptosis in high glucose cultures are caused by excess superoxide produced during enhanced respiration (mitochondrial oxidative metabolism of glucose). Superoxide is precursor to all Reactive Oxygen Species (ROS) which, in turn, cause oxidative stress. The rate of respiration and thus the ROS production is regulated by mitochondrial carbonic anhydrases (mCA) VA and VB, the two isoforms expressed in the mitochondria. Inhibition of both mCA: decreases the oxidative stress and restores the pericyte numbers in diabetic brain; and reduces high glucose-induced respiration, ROS, oxidative stress, and apoptosis in cultured brain pericytes. However, the individual role of the two isoforms has not been established. To investigate the contribution of mCA VA in ROS production and apoptosis, a mCA VA overexpressing brain pericyte cell line was engineered. These cells were exposed to high glucose and analyzed for the changes in ROS and apoptosis. Overexpression of mCA VA significantly increased pericyte ROS and apoptosis. Inhibition of mCA VA with topiramate prevented increases both in glucose-induced ROS and pericyte death. These results demonstrate, for the first time, that mCA VA regulates the rate of pericyte respiration. These findings identify mCA VA as a novel and specific therapeutic target to protect the cerebromicrovascular bed in diabetes.

Prevalence and risk factors for diabetes and diabetic retinopathy: results from the Nigeria national blindness and visual impairment survey

BACKGROUND

In Nigeria, urbanisation and increasing life expectancy are likely to increase the incidence of non-communicable diseases. As the epidemic of diabetes matures, visual loss from diabetic retinopathy (DR) will increase unless mechanisms for early detection and treatment improve, and health systems respond to the growing burden of non-communicable diseases.

METHODS

A nationally-representative population-based sample of 13,591 participants aged ≥40 years selected by multistage-stratified-cluster-random-sampling with probability-proportional-to-size procedures were examined in 305 clusters in Nigeria between January 2005 to June 2007. All were asked about history of diabetes and underwent basic eye examination. Visual acuity (VA) was measured using logMAR E-chart. Participants with VA<6/12 and/or DR detected underwent detailed eye examination including dilated retinal examination and retinal photography. Systematic sampling of 1-in-7 gave a subsample (n=1759) examined in detail regardless of VA; and had random blood glucose (RBG) testing. Images were graded by Moorfields Eye Hospital Reading Centre. Participants were defined as having diabetes if they were previously diagnosed or RBG>11.1mmol/l or had DR. Data in the subsample were used to estimate the prevalence and to analyse risk factors for diabetes and DR using multivariable logistic regression. Additional information on the types of DR was obtained from participants not in the subsample.

RESULTS

In the subsample, 164 participants were excluded due to missing data; and 1,595 analysed. 52/1,595 had diabetes, a prevalence of 3.3% (95%CI 2.5-4.3%); and 25/52(48%) did not know. Media opacity in 8/52 precluded retinal examination. 9/44(20.5%) had DR. Higher prevalence of diabetes was associated with urban residence (Odds ratio [OR]1.87) and overweight/obesity (OR3.02/4.43 respectively). Although not statistically significant, DR was associated with hypertension (OR3.49) and RBG>15.0mmol/L (OR8.10). Persons with diabetes had 3 times greater odds of blindness. Of 11,832 other participants in the study sample, 175(1.5%) had history of diabetes; 28 had DR. Types of DR (total=37) included 10.8% proliferative, 51.4% macular oedema.

CONCLUSION

The age-adjusted prevalence of diabetes in Nigeria was 3.25% (95%CI 2.50-4.30) and over 10% of people with diabetes aged ≥40 years had sight-threatening-DR. These data will enable the development of better public health strategies for the control of diabetes and planning services for DR to prevent vision loss.

Delay in diabetic retinopathy screening increases the rate of detection of referable diabetic retinopathy

AIMS

To assess whether there is a relationship between delay in retinopathy screening after diagnosis of type 2 diabetes and level of retinopathy detected.

METHODS

Patients were referred from 88 primary care practices to an English National Health Service diabetic eye screening programme. Data for screened patients were extracted from the primary care databases using semi-automated data collection algorithms supplemented by validation processes. The programme uses two-field mydriatic digital photographs graded by a quality assured team.

RESULTS

Data were available for 8183 screened patients with diabetes newly diagnosed in 2005, 2006 or 2007. Only 163 with type 1 diabetes were identified and were insufficient for analysis. Data were available for 8020 with newly diagnosed type 2 diabetes. Of these, 3569 were screened within 6 months, 2361 between 6 and 11 months, 1058 between 12 and 17 months, 366 between 18 and 23 months, 428 between 24 and 35 months, and 238 at 3 years or more after diagnosis. There were 5416 (67.5%) graded with no retinopathy, 1629 (20.3%) with background retinopathy in one eye, 753 (9.4%) with background retinopathy in both eyes and 222 (2.8%) had referable diabetic retinopathy. There was a significant trend (P = 0.0004) relating time from diagnosis to screening detecting worsening retinopathy. Of those screened within 6 months of diagnosis, 2.3% had referable retinopathy and, 3 years or more after diagnosis, 4.2% had referable retinopathy.

CONCLUSIONS

The rate of detection of referable diabetic retinopathy is elevated in those who were not screened promptly after diagnosis of type 2 diabetes.

Psychological distress, cardiovascular complications and mortality among people with screen-detected type 2 diabetes: follow-up of the ADDITION-Denmark trial

AIMS/HYPOTHESIS

The aim of this study was to examine the association between psychological distress and the risk of cardiovascular disease (CVD) events and all-cause mortality in patients with screen-detected type 2 diabetes mellitus. In addition, we explored whether or not metabolic control and medication adherence could explain part of this association.

METHODS

A follow-up study was performed including 1,533 patients aged 40-69 years with screen-detected type 2 diabetes mellitus identified in general practice during 2001-2006 in the Denmark arm of the ADDITION (Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care) study. Mental health was measured at baseline with the Mental Health Inventory 5 (MHI-5). Psychological distress was defined as an MHI-5 score of ≤ 68 (18.2% of the population). CVD risk factors were measured at baseline and repeated at the follow-up examination. Information on death, hospital discharge diagnosis, and antihypertensive and lipid-lowering drug treatment was obtained from national registers. Cox proportional regression was used to estimate HRs for the association between psychological distress, CVD events and all-cause mortality. Age- and sex-adjusted risk difference analyses were performed to estimate differences in meeting treatment targets.

RESULTS

Patients with psychological distress had a 1.8-fold higher mortality rate (HR 1.76, 95% CI 1.23, 2.53) and a 1.7-fold higher risk of having a CVD event (HR: 1.69, 95% CI 1.05, 2.70) compared with those with an MHI-5 score of >68. Overall, psychological distress was not associated with the ability to meet treatment targets for HbA1c levels, cholesterol levels or BP, or to redeem antihypertensive or lipid-lowering drug treatment.

CONCLUSIONS/INTERPRETATION

In people detected and treated early in the diabetes disease trajectory, those with psychological distress at the time of diagnosis had a higher risk of CVD events and death than those without psychological distress.

Epidemiological issues in diabetic retinopathy

There is currently an epidemic of diabetes in the world, principally type 2 diabetes that is linked to changing lifestyle, obesity, and increasing age of the population. Latest estimates from the International Diabetes Federation (IDF) forecasts a rise from 366 million people worldwide to 552 million by 2030. Type 1 diabetes is more common in the Northern hemisphere with the highest rates in Finland and there is evidence of a rise in some central European countries, particularly in the younger children under 5 years of age. Modifiable risk factors for progression of diabetic retinopathy (DR) are blood glucose, blood pressure, serum lipids, and smoking. Nonmodifiable risk factors are duration, age, genetic predisposition, and ethnicity. Other risk factors are pregnancy, microaneurysm count in an eye, microaneurysm formation rate, and the presence of any DR in the second eye. DR, macular edema (ME), and proliferative DR (PDR) develop with increased duration of diabetes and the rates are dependent on the above risk factors. In one study of type 1 diabetes, the median individual risk for the development of early retinal changes was 9.1 years of diabetes duration. Another study reported the 25 year incidence of proliferative retinopathy among population-based cohort of type 1 patients with diabetes was 42.9%. In recent years, people with diabetes have lower rates of progression than historically to PDR and severe visual loss, which may reflect better control of glucose, blood pressure, and serum lipids, and earlier diagnosis.

Prevalence and risk factors of diabetic retinopathy in migrant Indians in an urbanized society in Asia: the Singapore Indian eye study

PURPOSE

To describe the prevalence of and risk factors for diabetic retinopathy (DR) in Indian persons living in a newly urbanized society in Asia.

DESIGN

Population-based study.

PARTICIPANTS

Ethnic Indians aged ≥40 years living in Singapore.

METHODS

The Singapore Indian Eye Study was conducted between 2007 and 2009. All participants underwent an extensive ophthalmic examination, including retinal photographs obtained after pupil dilation. These images were graded for the presence and severity of DR using the modified Airlie House classification system. Diabetes was defined as hemoglobin A1c level of ≥6.5%, use of diabetic medication, or a physician diagnosis of diabetes. Risk factors were measured using questionnaires, clinical assessments, or laboratory tests.

MAIN OUTCOME MEASURES

Any DR, diabetic macular edema (DME), or vision-threatening DR (VTDR).

RESULTS

Among the 3400 participants, the age-standardized prevalence was 33.6% (95% confidence interval [CI], 31.4-35.8) for diabetes and 10.5% (95% CI, 9.3-11.8) for DR. Among those with diabetes only, the age-standardized prevalence was 30.4% (95% CI, 26.5-34.8) for any DR, 7.2% (95% CI, 5.3-9.7) for DME, and 7.1% (95% CI, 5.4-9.5) for VTDR. In multivariate analysis, independent risk factors for any DR were younger age (odds ratio [OR], 0.98; 95% CI, 0.96-1.00, per year increase), longer diabetes duration (OR, 1.09; 95% CI, 1.07-1.11 per year increase), higher hemoglobin A1c (OR, 1.23; 95% CI, 1.13-1.34 per percent increase), higher systolic blood pressure (OR, 1.01; 95% CI, 1.00-1.02 per 1-mmHg increase), lower diastolic blood pressure (OR, 0.97; 95% CI, 0.96-0.99 per 1-mmHg increase), history of previous stroke (OR, 2.16; 95% CI, 1.12-4.16), and insulin treatment (OR, 2.99; 95% CI, 1.84-4.87). Similar independent risk factors, except for blood pressure, were found for VTDR. Additionally, persons with lower income and living in smaller houses were associated with VTDR.

CONCLUSIONS

One in 3 migrant Indians living in newly urbanized Asian societies have diabetes and 1 in 10 has DR. This is similar to rates reported in Western populations and significantly higher than those reported in India.

Retinopathy and visual impairment in diabetes, impaired glucose tolerance and normal glucose tolerance: the Nord-Trøndelag Health Study (the HUNT study)

PURPOSE

The aim of the study was to describe the prevalence of visual impairment and retinopathy and to investigate risk factors for retinopathy in persons with diabetes, screen-detected diabetes, impaired glucose tolerance and normal glucose tolerance in a subpopulation of the HUNT study.

METHODS

We used a sample (n = 163) from a population-based screening survey of hyperglycaemia, undertaken in 2004-2005 in Verdal, Norway. Baseline information was accessible through the second Nord-Trøndelag Health Study (HUNT2), 1995-97. Data collection was made in 2005 and included patient history, refraction, visual acuity, cataract assessment and single-field, nonmydriatic retinal photography. Retinal photographs were graded independently by two graders blinded to patient information. Data were analysed with standard statistical methods, and p < 0.05 was considered significant.

RESULTS

In all, 126 (77%) persons participated, 55% were women. The mean (SD) age was 59 (± 14) years. Four (3%) had correctable visual impairment, and none were visually impaired. Retinal photographs were gradable for both eyes in 109 (87%) participants. The prevalence of retinopathy was 11% in persons with known diabetes, 4% in persons with screen-detected diabetes, 3% in persons with impaired glucose tolerance and 10% in persons with normal glucose tolerance. Retinopathy was not associated with known history of diabetes or current glycaemic status. Nonfasting plasma glucose (in 1995-97) was an independent risk factor for retinopathy (in 2005), OR (95% CI) 1.5 (1.01, 2.13), p = 0.046.

CONCLUSION

The prevalence of diabetic retinopathy in persons with diabetes in this study was low. Appropriate optical correction and regular eye examination can prevent unnecessary visual impairment in both persons with and without diabetes.

Does haptoglobin genotype affect early onset of diabetic retinopathy in patients with type 2 diabetes?

PURPOSE

There are 2 common alleles for Hp (Hp-1 and Hp-2) and 3 common Hp genotypes: Hp1-1, Hp2-1, and Hp2-2. The haptoglobin genotype may play a dual role in morbidities of diabetes: Hp1-1, protective and Hp2-2, provocative. This study investigated the possible association of haptoglobin genotypes with onset of retinopathy in Type 2 diabetes (DM2).

METHODS

The sample included 98 consecutive adults with DM2 under routine outpatient follow-up from 2007 to 2009 who met the criteria for either no retinopathy at ≥10 years after diagnosis (Group 1) or proliferative retinopathy at ≤10 years after diagnosis (Group 2). Blood samples were collected for haptoglobin genotyping by polymerase chain reaction. Findings were compared between and within groups.

RESULTS

Eighty-four patients had no retinopathy and 14 had early proliferative retinopathy. The distributions of the Hp genotypes were as follows: no-retinopathy group: 28.6% Hp1-1, 35.7% Hp2-1, and 35.7% Hp2-2 and proliferative retinopathy group: 22.6% Hp1-1, 27.4% Hp2-1, and 50% Hp2-2 (NS). On statistical analysis (limited to the larger no-retinopathy group), a predominance of Hp1-1 was noted in older patients; Hp2-2 was associated with an increased rate of stroke.

CONCLUSION

The Hp genotype apparently plays no role in the development or worsening of proliferative retinopathy in DM2. Hp1-1 may be involved in delaying the onset of diabetes. Hp2-2 may pose a microvascular risk.

Prevalence of neuropathy and peripheral arterial disease and the impact of treatment in people with screen-detected type 2 diabetes: the ADDITION-Denmark study

OBJECTIVE

There is limited evidence on how intensive multifactorial treatment (IT) improves outcomes of diabetes when initiated in the lead time between detection by screening and diagnosis in routine clinical practice. We examined the effects of early detection and IT of type 2 diabetes in primary care on the prevalence of diabetic peripheral neuropathy (DPN) and peripheral arterial disease (PAD) 6 years later in a pragmatic, cluster-randomized parallel group trial.

RESEARCH DESIGN AND METHODS

A stepwise screening program in 190 general practices in Denmark was used to identify 1,533 people with type 2 diabetes. General practices were randomized to deliver either IT or routine care (RC) as recommended through national guidelines. Participants were followed for 6 years and measures of DPN and PAD were applied.

RESULTS

We found no statistically significant effect of IT on the prevalence of DPN and PAD compared with RC. The prevalence of an ankle brachial index ≤0.9 was 9.1% (95% CI 6.0-12.2) in the RC arm and 7.3% (5.0-9.6) in the IT arm. In participants tested for vibration detection threshold and light touch sensation, the prevalence of a least one abnormal test was 34.8% (26.7-43.0) in the RC arm and 30.1% (24.1-36.1) in the IT arm.

CONCLUSIONS

In a population with screen-detected type 2 diabetes, we did not find that screening followed by IT led to a statistically significant difference in the prevalence of DPN and PAD 6 years after diagnosis. However, treatment levels were high in both groups.

Predicting the risk of diabetic retinopathy in type 2 diabetic patients

AIMS

Diabetic retinopathy (DR) is often asymptomatic even in its more advanced stages. Timely and repeated screening for DR avoids a late diagnosis of DR, but the high number of diabetic patients precludes a frequent screening; thus, the need for a method to identify patients at higher risk for DR becomes crucial.

METHODS

A prospective analysis of 5034 type 2 diabetic patients followed from 1996 to 2007 and not affected by retinopathy at the time of the recruitment was performed. Patients were randomly divided (ratio 2:1) into two groups: the train data set and the test set (3327 and 1707 patients, respectively). Factors associated with the occurrence of DR were assessed by the Cox's proportional hazard model.

RESULTS

Duration of diabetes, glycosylated hemoglobin, systolic blood Pressure, male gender, albuminuria and diabetes therapy other than diet were all significantly associated with the occurrence of DR.

CONCLUSIONS

The nomogram could help in ranking the type 2 diabetic patients at higher risk to develop DR and thus with a need for more frequent ophthalmologic checks, without enhancing neither the time nor the costs.

Comparison of different stepwise screening strategies for type 2 diabetes: Finding from Danish general practice, Addition-DK

AIM

To examine attendance, number of people with T2DM and costs of three different stepwise screening strategies for T2DM in general practice (GP).

METHODS

Diabetes risk questionnaires were mailed to individuals aged 40-69 years from 45 general practices in 2001-2002 and individuals at high risk for T2DM, were asked to contact their GP to arrange a screening test. In 2005-2006, 26 general practices were randomised into two different opportunistic screening programmes (OP-direct and OP-subsequent) and risk questionnaires were distributed to individuals aged 40-69 years during GP consultations. In the OP-direct approach, high-risk individuals were offered to start the screening during the actual consultation while high-risk individuals in the OP-subsequent approach, were invited to a screening test at a later date. We report attendance, number of people with T2DM and costs of each screening approach.

RESULTS

The mail-distributed approach identified 0.8% of the target population with T2DM, the OP-direct approach and the OP-subsequent approach, 0.9% and 0.5% respectively. Cost per person with T2DM was in the mail-distributed approach: € 1058, OP-direct approach: € 707 and the OP-subsequent approach: € 727.

CONCLUSION

This study indicates that opportunistic screening identifies the same level of unknown diabetes as a mail-distributed approach but with lower costs.