Risk factors for the development of diabetic retinopathy in Japanese type 2 diabetic patients

Incidence of diabetic retinopathy in newly diagnosed subjects with type 2 diabetes mellitus over 5 years: Contribution of Β-cell function

AIMS

Identifying and modulating risk factors is essential to prevent visual impairment due to diabetic retinopathy (DR). This study examines incident DR with metabolic and hormonal factors in newly-diagnosed, treatment naïve, individuals with Type2 Diabetes Mellitus (T2DM), over a 5 year period from diagnosis.

METHODS

233 T2DM subjects underwent serial DR screening using digital photography and standardised Meal Tolerance Tests at diagnosis and after 1, 2 and 5 years. Subjects (179) with no DR throughout the 5-year study period were compared with those who developed DR (54).

RESULTS

Of 233 subjects, 54(23.2%) developed DR by 5 years, background DR in 50(93%) and exudative maculopathy in 4(7%) individuals. Of these subjects, 12(22%) developed DR after 1 year, 15(28%) after 2 years and 27(50%) after 5 years. At baseline, those with DR at 5 years had higher HbA_1c (p = 0.017), higher fasting plasma glucose (PG) (p = 0.031) and postprandial PG (p = 0.009). They were associated with reduced basal β-cell secretory function (M₀) (p = 0.025), lower (p = 0.000) postprandial β-cell responsiveness (M₁) and β-cell function (HOMA-B) (p = 0.044).

CONCLUSIONS

There is an independent association between glycaemic control and β-cell dysfunction at the time of diagnosis of T2DM, with incident DR over a follow-up period of 5 years.

Weight change and microvascular outcomes in patients with new-onset diabetes: a nationwide cohort study

BACKGROUND/AIMS

Because weight control is important in treatment of type 2 diabetes, it is essential to understand the associations between weight change and the risk of microvascular complications among patients with type 2 diabetes. We examined whether weight changes early after new-onset diabetes have an impact on the clinical outcomes of diabetic nephropathy and retinopathy.

METHODS

Using the Korean National Health Insurance Service-National Health Screening Cohort database, 181,872 patients newly diagnosed with type 2 diabetes who were free of end-stage renal disease (ESRD) and proliferative diabetic retinopathy (PDR) during 2007 to 2012 were followed to the end of 2016. Weight change was defined as the difference in body weight from the time of diabetes diagnosis to 2 years later.

RESULTS

We identified 180 cases of ESRD and 780 cases of PDR followed up for a median of 5.5 years from the index year at 2 years after diagnosis. Those with 5% to 10% weight gain showed a significantly higher hazard ratio (HR) for ESRD, compared with those with ≤ 5% weight change after adjusting for several confounding factors, including the baseline estimated glomerular filtration rate (HR, 1.75; 95% confidence interval [CI], 1.14 to 2.70). Those with ≥ 10% weight loss showed the lowest HR for PDR (HR, 0.52; 95% CI, 0.33 to 0.83), whereas those with ≥ 10% weight gain showed the highest HR for PDR (HR, 3.20; 95% CI, 2.51 to 4.08).

CONCLUSION

Weight gain after new-onset diabetes was associated with increased risk of ESRD and PDR whereas weight loss with decreased risk of PDR, but not ESRD.

Prevalence of and Factors Associated with Diabetic Retinopathy in Patients with Diabetes Mellitus at Siriraj Hospital - Thailand's Largest National Tertiary Referral Center

PURPOSE

We aimed to determine the prevalence of and factors associated with diabetic retinopathy (DR) in patients with diabetes mellitus (DM) and to evaluate the relationship between significant factors and severity of DR.

PATIENTS AND METHODS

A retrospective cross-sectional study of 1130 diabetic patients (mean age: 60 years, 62.7% female, 91% type 2 diabetes) was conducted in the diabetes clinic of Siriraj Hospital (Bangkok, Thailand) during January 2012 to June 2015. DR was graded as absent, mild, moderate, or severe non-proliferative DR, or proliferative DR. Multivariate logistic regression analysis was used to identify independent risk factors for DR in DM patients.

RESULTS

The overall prevalence of DR was 34.78%. Multivariate analysis revealed duration of diabetes, glycated hemoglobin level (HbA_1c), presence of albuminuria, and abnormal protective sensation to be independent risk factors for DR. The prevalence of DR increased with longer duration of diabetes (p < 0.001), deterioration of glucose control (p = 0.006 for HbA_1c), presence of significant albuminuria (p = 0.010), and loss of protective sensation (p = 0.001).

CONCLUSION

In this study, one-third of DM were found to have DR. The independent predictors of DR were duration of diabetes, HbA_1c level, presence of significant albuminuria, and impaired protective sensation. Heightened awareness of these risk factors will decrease the prevalence and severity of DR, and will improve early diagnosis and treatment of DR.

Vascular changes in diabetic retinopathy-a longitudinal study in the Nile rat

Diabetic retinopathy is the most common microvascular complication of diabetes and is a major cause of blindness, but an understanding of the pathogenesis of the disease has been hampered by a lack of accurate animal models. Here, we explore the dynamics of retinal cellular changes in the Nile rat (Arvicanthis niloticus), a carbohydrate-sensitive model for type 2 diabetes. The early retinal changes in diabetic Nile rats included increased acellular capillaries and loss of pericytes that correlated linearly with the duration of diabetes. These vascular changes occurred in the presence of microglial infiltration but in the absence of retinal ganglion cell loss. After a prolonged duration of diabetes, the Nile rat also exhibits a spectrum of retinal lesions commonly seen in the human condition including vascular leakage, capillary non-perfusion, and neovascularization. Our longitudinal study documents a range and progression of retinal lesions in the diabetic Nile rat remarkably similar to those observed in human diabetic retinopathy, and suggests that this model will be valuable in identifying new therapeutic strategies.

Incidence and progression of diabetic retinopathy: a systematic review

Diabetic retinopathy is a leading cause of vision impairment and blindness. We systematically reviewed studies published from Jan 1, 1980, to Jan 7, 2018, assessed the methodological quality, and described variations in incidence of diabetic retinopathy by region with a focus on population-based studies that were conducted after 2000 (n=8, including two unpublished studies). Of these eight studies, five were from Asia, and one each from the North America, Caribbean, and sub-Saharan Africa. The annual incidence of diabetic retinopathy ranged from 2·2% to 12·7% and progression from 3·4% to 12·3%. Progression to proliferative diabetic retinopathy was higher in individuals with mild disease compared with those with no disease at baseline. Our Review suggests that more high-quality population-based studies capturing data on the incidence and progression of diabetic retinopathy with stratification by age and sex are needed to consolidate the evidence base. Our data is useful for conceptualisation and development of major public health strategies such as screening programmes for diabetic retinopathy.

Association of obesity and risk of diabetic retinopathy in diabetes patients: A meta-analysis of prospective cohort studies

BACKGROUND

Diabetic retinopathy (DR) was considered to be a common complication of diabetes. The purpose of the current study was to investigate the potential association between obesity and DR risk by conducting a meta-analysis of prospective studies.

METHODS

A consummate literature search of PubMed, EMBASE, and web of science was conducted until July 2016. A total of 13 prospective cohort studies were included in this meta-analysis.

RESULTS

On meta-analysis of all the studies assessing DR risk, obesity was associated with a significant increase in DR incidence (relative risk [RR], 1.20; 95% confidence interval [CI], 1.01-1.43; I = 59.6%). When only proliferative DR (PDR) was considered, no significant association between obesity and risk of PDR was detected. Significant harmful effect was detected in type 2 diabetes mellitus (T2DM) group (RR, 1.40; 95% CI, 1.05-1.87; I = 67.6%) but not mixed group (RR, 1.04; 95% CI, 0.97-1.18; I = 0.00%). No significant publication bias was detected in the selected 13 studies.

CONCLUSION

Obesity was a risk factor for non-proliferative DR. However additional well-designed and well-conducted epidemiologic studies were required to deepen our understanding of the relation between obesity and DR.

Excess visceral adiposity is associated with diabetic retinopathy in a multiethnic Asian cohort with longstanding type 2 diabetes

Purpose/Aim: Diabetic retinopathy (DR) is the most common diabetic microvascular complication, and it typically develops after 10 years of diabetes diagnosis. The primary aim of this study was to evaluate the association between adiposity and DR susceptibility among individuals with longstanding type 2 diabetes mellitus (T2D).

MATERIALS AND METHODS

In this cross-sectional study, DR was assessed by fundus photography in 953 T2D subjects. DR prevalence by categories of T2D duration was evaluated. In a sub-cohort analysis, subjects having T2D for ≥10 years were divided into DR (N = 241) and non-DR (N = 377) groups. Measures of adiposity including body mass index (BMI), waist circumference (WC), and visceral fat area (VFA) were analyzed. Urinary albumin:creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) were measured.

RESULTS

DR prevalence markedly increased 10 years after T2D diagnosis (p < 0.001). Among subjects with T2D duration ≥10 years, BMI, WC, and VFA were elevated in DR compared with non-DR (all p < 0.05). Contrasting with BMI and WC, the association between VFA and DR sustained adjustment for demographics, metabolic factors, and insulin treatment (OR: 1.060, 95% CI: 1.004-1.119, p = 0.035). However, the association became insignificant after controlling for ACR and eGFR. Mediation analysis revealed that ACR and eGFR explained 47.3% of the relationship between VFA and DR.

CONCLUSIONS

The findings suggest that visceral adiposity is associated with DR in individuals with longstanding T2D. This relationship may be attributable to generalized vascular injury as reflected by coexisting renal burden. Therefore, effective management of visceral adiposity and ameliorating renal burden may ameliorate susceptibility to DR.

Relation Between Different Measures of Glycemic Exposure and Microvascular and Macrovascular Complications in Patients with Type 2 Diabetes Mellitus: An Observational Cohort Study

INTRODUCTION

This retrospective cohort study investigated the relation between different measures of glycemic exposure and micro- and macrovascular complications among patients with type 2 diabetes.

METHODS

The analysis included patients receiving oral antihyperglycemic agents between 1 January 2006 and 31 December 2014 from the General Practitioner Database from the PHARMO Database Network. All recorded HbA1c levels during follow-up were used to express glycemic exposure in four ways: index HbA1c, time-dependent HbA1c, exponential moving average (EMA) and glycemic burden. Association between glycemic exposure and micro-/macrovascular complications was analyzed by estimating hazard ratios and 95% confidence intervals using an adjusted (time-dependent) Cox proportional hazards model.

RESULTS

The analysis included 32,725 patients (median age, 65 years; 47% female). Median follow-up was 5.4 years; median number of HbA1c measurements per patient was 18.0. From all measures, HbA1c at index showed the weakest relation between all micro-/macrovascular complications, with coronary artery disease (CAD) having the highest HR (95% CI): 1.18 (1.04-1.34) for HbA1c ≥64 mmol/mol (8%). The time-dependent HbA1c model showed a significant association only for microvascular complications, with retinopathy having the highest HR (95% CI): 1.55 (1.40-1.73) for HbA1c ≥64 mmol/mol (8%). EMA-defined exposure showed similar findings, although the effect of retinopathy was more pronounced [HR (95% CI): 1.81 (1.63-2.02) for HbA1c ≥64 mmol/mol (8%)] and was also predictive for CAD [HR (95% CI): 1.29 (1.10-1.50) for HbA1c ≥64 mmol/mol (8%)]. A statistically significant relation with glycemic burden was found for all selected micro-/macrovascular complications, with retinopathy having the highest HR (95%): 2.60 (2.19-3.07) for glycemic burden years >3.

CONCLUSION

This study shows that greater and more prolonged exposure to hyperglycemia increases the risk of micro- and macrovascular complications.

FUNDING

Janssen Pharmaceutica NV.

Body mass index and risk of diabetic retinopathy: A meta-analysis and systematic review

Diabetic retinopathy (DR) is a frequent cause of acquired blindness worldwide. Various studies have reported the effects of body mass index (BMI) on the risk of DR, but the results remain controversial. Therefore, a meta-analysis was performed to evaluate the relationship between BMI and the risk of DR.A systematic search was performed using the Cochrane Library, PubMed, and Embase databases to obtain articles published through December 2016. Articles regarding the association between BMI and the risk of DR were retrieved. The adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) were included and then pooled with a random effects model.A total of 27 articles were included in this meta-analysis. When BMI was analyzed as a categorical variable, neither being overweight (OR = 0.89, 95% CI 0.75-1.07; P = .21; I = 65%) nor obesity (OR = 0.97, 95% CI 0.73-1.30; P = .86) were associated with an increased risk of DR when compared with normal weight. When BMI was analyzed as a continuous variable, a higher BMI was not associated with an increased risk of DR (OR = 0.99, 95% CI 0.97-1.01; P = .25; I2 = 79%). The pooled results did not significantly change after the sensitivity analysis.Based on the current publications, neither being overweight nor obesity is associated with an increased risk of DR. Further studies should confirm these findings.

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.

Circulating Biomarkers of Diabetic Retinopathy: An Overview Based on Physiopathology

Diabetic retinopathy (DR) is the main cause of working-age adult-onset blindness. The currently available treatments for DR are applicable only at advanced stages of the disease and are associated with significant adverse effects. In early stages of DR the only therapeutic strategy that physicians can offer is a tight control of the risk factors for DR. Therefore, new pharmacological treatments for these early stages of the disease are required. In order to develop therapeutic strategies for early stages of DR new diagnostic tools are urgently needed. In this regard, circulating biomarkers could be useful to detect early disease, to identify those diabetic patients most prone to progressive worsening who ought to be followed up more often and who could obtain the most benefit from these therapies, and to monitor the effectiveness of new drugs for DR before more advanced DR stages have been reached. Research of biomarkers for DR has been mainly based on the pathogenic mechanism involved in the development of DR (i.e., AGEs, oxidative stress, endothelial dysfunction, inflammation, and proangiogenic factors). This review focuses on circulating biomarkers at both early and advanced stages that could be relevant for the prediction or detection of DR.

Mean HbA1c and mortality in diabetic individuals with heart failure: a population cohort study

AIMS

Controversy exists regarding the importance of glycaemic control in patients with type 2 diabetes mellitus (T2DM) and chronic heart failure (CHF) based on conflicting reports using single baseline glycosyated haemoglobin (HbA1c ). Using the time-weighted mean of serial HbA1c measurements has been found to be a better predictor of diabetic complications as it reflects the glycaemic burden for that individual over time. We therefore sought to confirm this in a large cohort of patients with T2DM and incident CHF.

METHODS AND RESULTS

A time-weighted mean HbA1c was calculated using all HbA1c measurements following CHF diagnosis. Patients were grouped into five categories of HbA1c (≤6.0%, 6.1-7.0%, 7.1-8.0%, 8.1-9.0%, and >9.0%). The relationship between time-weighted mean HbA1c and all-cause death after CHF diagnosis was assessed. A total of 1447 patients with T2DM met the study criteria. During a median follow-up of 2.8 years, there were 826 (57.1%) deaths, with a crude death rate of 155 deaths per 1000 person-years [95% confidence interval (CI) 144-166]. A Cox regression model, adjusted for all significant predictors, with the middle HbA1c category (7.1-8.0%) as the reference, showed a U-shaped relationship between HbA1c and outcome [HbA1c <6.0%, hazard ratio (HR) 2.5, 95% CI 1.8-3.4; HbA1c 6.1-7.0%, HR 1.4, 95% 1.1-1.7; HbA1c 8.1-9.0%, HR 1.3, 95% CI 1.0-1.6; and HbA1c >9.0%, HR 1.8, 95% CI 1.4-2.3]. Further analysis revealed a protective effect of insulin sensitizers (i.e. metformin) (HR 0.7, 95% CI 0.61-0.93) but not other drug classes.

CONCLUSIONS

In patients with T2DM and CHF, our study shows a U-shaped relationship between HbA1c and mortality, with the lowest risk in patients with modest glycaemic control (HbA1c 7.1-8.0%) and those treated with insulin sensitizers.

Systemic arteriosclerosis and eating behavior in Japanese type 2 diabetic patients with visceral fat accumulation

Background

Visceral fat accumulation is a major etiological factor in the progression of type 2 diabetes mellitus and atherosclerosis. We described previously visceral fat accumulation and multiple cardiovascular risk factors in a considerable number of Japanese non-obese subjects (BMI <25 kg/m²). Here, we investigated differences in systemic arteriosclerosis, serum adiponectin concentration, and eating behavior in type 2 diabetic patients with and without visceral fat accumulation.

Methods

The study subjects were 75 Japanese type 2 diabetes mellitus (age: 64.8 ± 11.5 years, mean ± SD). Visceral fat accumulation represented an estimated visceral fat area of 100 cm² using the bioelectrical impedance analysis method. Subjects were divided into two groups; with (n = 53) and without (n = 22) visceral fat accumulation. Systemic arteriosclerosis was scored for four arteries by ultrasonography. Eating behavior was assessed based on The Guideline for Obesity questionnaire issued by the Japan Society for the Study of Obesity.

Results

The visceral fat accumulation (+) group showed significantly higher systemic vascular scores and significantly lower serum adiponectin levels than the visceral fat accumulation (−) group. With respect to the eating behavior questionnaire items, (+) patients showed higher values for the total score and many of the major sub-scores than (−) patients.

Conclusions

Type 2 diabetic patients with visceral fat accumulation showed 1) progression of systemic arteriosclerosis, 2) low serum adiponectin levels, and 3) differences in eating behavior, compared to those without visceral fat accumulation. Taken together, the findings highlight the importance of evaluating visceral fat area in type 2 diabetic patients. Furthermore, those with visceral fat accumulation might need to undergo more intensive screening for systemic arteriosclerosis and consider modifying their eating behaviors.

Genetics in diabetic retinopathy: current concepts and new insights

There is emerging evidence which indicates the essential role of genetic factors in the development of diabetic retinopathy (DR). In this regard it should be highlighted that genetic factors account for 25-50% of the risk of developing DR. Therefore, the use of genetic analysis to identify those diabetic patients most prone to developing DR might be useful in designing a more individualized treatment. In this regard, there are three main research strategies: candidate gene studies, linkage studies and Genome-Wide Association Studies (GWAS). In the candidate gene approach, several genes encoding proteins closely related to DR development have been analyzed. The linkage studies analyze shared alleles among family members with DR under the assumption that these predispose to a more aggressive development of DR. Finally, Genome-Wide Association Studies (GWAS) are a new tool involving a massive evaluation of single nucleotide polymorphisms (SNP) in large samples. In this review the available information using these three methodologies is critically analyzed. A genetic approach in order to identify new candidates in the pathogenesis of DR would permit us to design more targeted therapeutic strategies in order to decrease this devastating complication of diabetes. Basic researchers, ophthalmologists, diabetologists and geneticists should work together in order to gain new insights into this issue.

Glycemic exposure and blood pressure influencing progression and remission of diabetic retinopathy: a longitudinal cohort study in GoDARTS

OBJECTIVE

This study sought to investigate the progression and regression of diabetic retinopathy (DR) and the effects of population risk factors on the rates of transition across retinopathy stages.

RESEARCH DESIGN AND METHODS

The study cohort consisted of 44,871 observed DR events between the calendar years 1990 and 2011 for 4,758 diabetic patients who were diagnosed at 35 years of age or older. The first retinal observation was recorded within a year from diagnosis, and the result was recorded as free of retinopathy. A multistate Markov model was applied for analyzing the development of DR and its relation to the patterns of changes in risk factors.

RESULTS

We observed a consistent risk effect of HbA1c on the progression (no retinopathy to mild background DR [BDR] hazard ratio per SD of HbA1c [HR] 1.42 [95% CI 1.32-1.52], mild BDR to observable BDR HR 1.32 [95% CI 1.08-1.60], and observable BDR to severe nonproliferative/proliferative DR HR 2.23 [95% CI 1.16-4.29]). Similarly, systolic blood pressure (SBP) and diastolic blood pressure increased the risk for the transition from the asymptomatic phase to mild BDR (HR 1.20 [95% CI 1.11-1.30]) and the mild BDR to observable BDR (HR 1.87 [95% CI 1.46-2.40]), respectively. Regression from mild BDR to no DR was associated with lower SBP (HR 0.79 [95% CI 0.64-0.97]) and lower HbA1c (HR 0.76 [95% CI 0.64-0.89]).

CONCLUSIONS

Progression and regression of DR were strongly associated with blood pressure and glycemic exposure.

Vascular complications and changes in body mass index in Japanese type 2 diabetic patients with abdominal obesity

Background

Although many Asian type 2 diabetic patients have been considered to be not obese and have low capacity of insulin secretion, the proportion of obese patients with visceral fat accumulation has increased in recent years. We found previously considerable number of Japanese non-obese subjects (body mass index (BMI) < 25 kg/m²) with visceral fat accumulation and multiple cardiovascular risk factors. The aim of the study was to investigate the difference in clinical features of type 2 diabetic patients with and without visceral fat accumulation, focusing on vascular complications and changes in BMI.

Methods

We enrolled 88 Japanese hospitalized type 2 diabetic patients. Abdominal obesity represented waist circumference (WC) of ≥85 cm for males and ≥90 cm for females (corresponding to visceral fat area of 100 cm²). Subjects were divided into two groups; with or without abdominal obesity.

Results

Hypertension, dyslipidemia and cardiovascular diseases were significantly more in the patients with abdominal obesity. The prevalence of cardiovascular disease in the non-obese patients (BMI < 25 kg/m²) with abdominal obesity were similar in obese patients (BMI ≥25 kg/m²). The mean BMI of the patients with abdominal obesity was < 25 kg/m² at 20 years of age, but reached maximum to more than 30 kg/m² in the course. Furthermore, substantial portion of the type 2 diabetic patients (52% in males and 43% in females) were not obese at 20 year-old (BMI < 25 kg/m²), but developed abdominal obesity by the time of admission.

Conclusion

These results emphasize the need to control multiple risk factors and prevent atherosclerotic disease in patients with abdominal obesity. The significant weight gain after 20 years of age in patients with abdominal obesity stresses the importance of lifestyle modification in younger generation, to prevent potential development of type 2 diabetes and future atherosclerotic cardiovascular disease.

Screening for diabetes in schoolchildren in Trinidad, West Indies

BACKGROUND

Although the epidemic of diabetes in adults is well established and documented, information on the epidemiology of type 2 diabetes mellitus (T2DM) in children and adolescents in Trinidad and Tobago is limited. Anecdotal reports suggest an increase in children and especially adolescents with T2DM amongst clinic attendees.

OBJECTIVE

To assess the prevalence of diabetes mellitus in schoolchildren screened by mass urinary testing in Trinidad and to determine the effectiveness and cost-effectiveness of this screening method.

DESIGN AND METHODS

During January to June 2009, a cross-sectional survey was undertaken in schoolchildren aged 5-17 years, in the island of Trinidad only. Children were instructed to collect an early-morning, pre-breakfast urine sample at home and to bring it to school for testing for glycosuria. Those with an initially positive result underwent a second urine test. Those with two consecutively positive urine tests were invited to undertake an oral glucose tolerance test.

RESULTS

67,000 (53·6%) children from a school-age population of 125,000 were screened. Twenty-three were found to have persistent glycosuria and 21 agreed to undergo an oral glucose tolerance test. Eight fulfilled the American Diabetes Association's criteria for diabetes and five for pre-diabetes. Of the eight with confirmed diabetes (aged 7-18 years), one (male, age 12 years) was slim and ketotic and required insulin for control. Of the other seven, five were overweight (three females, two males) with a BMI >85th per centile and two females were obese (BMI >95th per centile). Five children (four females, one male) aged 12-14 years were diagnosed as pre-diabetic. There is a prevalence of 10·4/100,000 schoolchildren with T2DM, and 7·5/100,000 with impaired glucose intolerance among schoolchildren in Trinidad. Urine screening had a positive predictive value (PPV) of 65% for detecting T2DM in schoolchildren. The cost of screening 67,000 children was US$55,080, a per capita cost of <US$1. The cost of finding one case was US$4286. Economic analysis revealed that investing to find one case today yields a net present value of >US$7000, representing a 63% saving.

CONCLUSION

Despite the low PPV of urine glucose testing, our data support the view that mass screening of schoolchildren in Trinidad for T2DM is both feasible and cost-effective.

Incidence of diabetic retinopathy in Bangladesh: a 15-year follow-up study

BACKGROUND

The aim of the present study was to estimate the incidence of diabetic retinopathy (DR) among type 2 diabetic (T2D) subjects in Bangladesh.

METHODS

A random sample of 977 patients with T2D was recruited retrospectively in 2008 from newly diagnosed T2D patients who had attended the Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorder (BIRDEM) in 1993. Baseline information for the cohort was collected for 1993 from hospital records. The mean time until development of DR in newly diagnosed T2D patients was calculated using survival analysis. Cox's proportional hazards model was used to assess factors affecting the time until development of DR.

RESULTS

The cumulative incidence of DR over the 15-year period was 50.6% (95% confidence interval [CI] 47.5%-53.8%). The incidence density (per 100 person-years) of DR was similar in the overall cohort (4.1; 95% CI 3.7-4.5) and in men (4.2; 95% CI 3.7-4.7) and women (4.1; 95% CI 3.6-4.6) separately. The mean time (in years) until development of DR in the cohort was 9.72 (95% CI 9.38-10.06), with similar times in men (9.8; 95% CI 9.3-10.3) and women (9.6; 95% CI 9.5-10.1) analyzed separately. Age, sex, hypertension, lipid profile, HbA1c, and serum creatinine were entered into the hazards model simultaneously. However, only age (hazard ratio [HR] 0.75; 95% CI 0.61-0.92) and HbA1c (HR 0.52; 95% CI 0.33-0.82) had a significant effect on the time until development of DR.

CONCLUSIONS

Glucose deregulation is the most important factor in the development of DR.

The shape of the metabolic memory of HbA1c: re-analysing the DCCT with respect to time-dependent effects

AIMS/HYPOTHESIS

We determined the shape of the metabolic memory of HbA1c and its contribution to retinopathy, as well as the importance of reducing HbA1c to prevent progression of retinopathy.

METHODS

The relative risk contribution of HbA1c values at different points in time to current progression of retinopathy was determined in the DCCT patients.

RESULTS

HbA1c 2 to 3 years earlier had the greatest relative risk contribution to current progression of retinopathy. HbA1c up to 5 years earlier made a greater contribution than current values, while values from 8 years earlier still had an important impact. When HbA1c had been at 8% for a long period and was subsequently lowered to 7%, the salutary effects did not begin to appear until 2 to 3 years after lowering. The hazard function for a constant level of HbA1c increased with time. The numbers needed to treat when reducing HbA1c from 8.3% to 8% from diagnosis was estimated to be 1,688 for the first 3 years and 13 for the period 9 to 12 years. Survival functions when reducing HbA1c from 8% to 7% show that pre-study glycaemic control dominates the effect on progression of retinopathy during the first years of a trial.

CONCLUSIONS/INTERPRETATION

The most harmful effect of hyperglycaemia on progression of retinopathy in type 1 diabetes initially increases, but declines after roughly 5 years. The salutary effect of reducing HbA1c accelerates with time and becomes greater in clinical practice than has been previously understood. Clinical trials should preferably be designed for long periods or include patients with low previous glycaemic exposure to distinguish trial effects from those of the metabolic memory.

Four years incidence of diabetic retinopathy and effective factors on its progression in type II diabetes

PURPOSE

To study the 4 years incidence of diabetic retinopathy in patients with type II diabetes and effective factors on its progression.

METHODS

Among diabetic patients referred to Yazd Diabetes Research Center, 120 patients with type II diabetes without diabetic retinopathy were selected. After complete ophthalmic examination, fasting blood sugar (FBS), postprandial blood sugar, triglyceride, and cholesterol were measured and height, weight, and blood pressure (BP) were recorded. Then patients were followed with eye examination yearly for 4 years.

RESULTS

Four-year cumulative incidence of diabetic retinopathy was 47.5% (95% CI: 38.6-56.4). The retinopathy was mild nonproliferative diabetic retinopathy (NPDR) in 43 (35.8%) whereas 10 (8.3%) patients had moderate NPDR, 3 (2.5%) patients had severe NPDR, and only one patient had proliferative diabetic retinopathy. The incidence of diabetic retinopathy was 5.8% in first year, 20.3% in the second year, 24.4% in the third year, and 7.4% in the fourth year. Duration of diabetes, FBS, and systolic BP had statistically significant relation with grades of diabetic retinopathy. However, there was no significant association between age, sex, body mass index, triglyceride, cholesterol, method of treatment, smoking, and diastolic BP with grades of diabetic retinopathy.

CONCLUSIONS

These data provide 4-year cumulative incidence of diabetic retinopathy in defined type 2 diabetic patients. The present study shows that duration of diabetes, hyperglycemia, and systolic BP appear to be the major factors associated with the development of any level of retinopathy in type 2 diabetic patients.

Risk factors for diabetic retinopathy in a South Indian Type 2 diabetic population--the Chennai Urban Rural Epidemiology Study (CURES) Eye Study 4

AIMS

To determine risk factors for diabetic retinopathy (DR) in an urban South Indian Type 2 diabetic population.

METHODS

The Chennai Urban Rural Epidemiology Study is a large cross-sectional study conducted in Chennai, South India. A total of 1736 Type 2 diabetic subjects were recruited for this study, which included 1382 known diabetic subjects (90.4% response rate) and 354 randomly selected, newly detected diabetic subjects diagnosed by oral glucose tolerance test. All subjects underwent four-field stereo retinal colour photography, graded by the Early Treatment Diabetic Retinopathy Study protocol.

RESULTS

Of the 1736 Type 2 diabetic subjects photographed, photographs could be graded in 1715 subjects. Stepwise ordinal logistic regression analysis revealed that male gender (P = 0.041), duration of diabetes (P < 0.0001), glycated haemoglobin (HbA(1c); P < 0.0001), macroalbuminuria (P = 0.0002) and insulin therapy (P = 0.0001) were significantly associated with severity of DR. The risk for developing DR was 7.7 times (95% confidence interval 4.71-12.48, P < 0.0001) for elevated postprandial plasma glucose levels compared with 4.2 times (95% confidence interval 2.78-6.34, P < 0.0001) for elevated fasting plasma glucose when the fourth quartile values were compared with the first quartile glucose values.

CONCLUSIONS

In South Indian Type 2 diabetic subjects, duration of diabetes, HbA1c, male gender, macroalbuminuria and insulin therapy were independent risk factors for severity of DR. Postprandial hyperglycaemia indicated a higher risk for DR compared with elevated fasting plasma glucose levels.

Peripheral neuropathy is an early complication of type 2 diabetes in adolescence

OBJECTIVE

To screen for microvascular complications in adolescents with type 2 diabetes mellitus (T2DM).

SUBJECTS AND METHODS

Seven adolescents with T2DM were assessed for early secondary complications. Median duration of diabetes was 1.8 (0.8-3.0) yr. All were assessed as follows: blood pressure, ophthalmologic examination for diabetic retinopathy, renal function, full blood count and vitamin B12 levels (to exclude B12 malabsorption - a side effect of metformin), random urine for microalbuminuria, an electrocardiogram (ECG) rhythm strip and podiatry performed by an experienced podiatrist. Testing for peripheral neuropathy included foot pulse palpation, tendo-Achilles reflexes, plantar callus test, large nerve fibre function (vibration and threshold for light touch/pressure) assessed by a 128-Hz tuning fork, and by the standard 10-g Semmes-Weinstein monofilament test, and small nerve fibre function (pain) assessed by pinprick neurotip.

RESULTS

Four adolescents had evidence of peripheral neuropathy on clinical examination, with abnormal large and small nerve fibre function. Six had plantar callus present, and four had weak but palpable posterior tibial pulses. All had normal tendo-Achilles reflex and normal response to vibration. None had diabetic retinopathy or hypertension. Renal function, full blood count (FBC), B12 levels and ECGs were normal. None of 120 adolescents with type 1 diabetes mellitus (T1DM) assessed by the same podiatrist had any signs of peripheral neuropathy.

CONCLUSIONS

Unlike T1DM, peripheral neuropathy can be present soon after diagnosis in those with T2DM. Children with T2DM need surveillance for complications from the time of diagnosis.

Rising incidence of type 2 diabetes in children in the U.K

OBJECTIVE

To estimate the incidence of type 2 diabetes in children <17 years of age and to investigate the relationship of diabetes with increasing childhood obesity in the U.K. and the Republic of Ireland (ROI).

RESEARCH DESIGN AND METHODS

Active monthly reporting of cases by consultant pediatricians occurred through the framework of the British Pediatric Surveillance Unit, with additional reports from specialist diabetes nurses. All children <17 years of age and diagnosed by their clinician as having non-type 1 diabetes from 1 October 2004 to 31 October 2005 were included.

RESULTS

A total of 168 confirmed cases of non-type 1 diabetes were reported, resulting in a national incidence (excluding the ROI) of 1.3 x 100,000(-1) x year(-1). Of these, 40% were diagnosed with type 2 diabetes giving a minimum incidence of 0.53 x 100,000(-1) x year(-1). Children of ethnic minorities were greatly overrepresented, with those of black and South-Asian origin (England data only) having an incidence of 3.9 and 1.25 x 100,000(-1) x year(-1), respectively, compared with 0.35 x 100,000(-1) x year(-1) in those defined as white. Of those diagnosed with type 2 diabetes, 95% were overweight and 83% obese according to International Obesity Task Force guidelines. Eighty-four percent had a family history of type 2 diabetes.

CONCLUSIONS

Type 2 diabetes is still less common than type 1 diabetes in U.K. children. However, compared with previous prevalence data, the frequency of type 2 diabetes appears to be increasing. Incidence among ethnic minorities is far higher than in whites, as previously described in the U.S. Increased adiposity and family history of type 2 diabetes were strongly associated with the diagnosis of type 2 diabetes in U.K. children.

Genome-wide linkage analyses to identify Loci for diabetic retinopathy

Hyperglycemia and long duration of diabetes are widely recognized risk factors for diabetic retinopathy, but inherited susceptibility may also play a role because retinopathy aggregates in families. A genome-wide linkage analysis was conducted in 211 sibships in which > or =2 siblings had diabetes and retinal photographs were available from a longitudinal study. These sibships were a subset of 322 sibships who had participated in a previous linkage study of diabetes and related traits; they comprised 607 diabetic individuals in 725 sibpairs. Retinal photographs were graded for presence and severity of diabetic retinopathy according to a modification of the Airlie House classification system. The grade for the worse eye was adjusted for age, sex, and diabetes duration and analyzed as a quantitative trait. Heritability of diabetic retinopathy in this group was 18% (95% CI 2-36). A genome-wide linkage analysis using variance components modeling found evidence of linkage on chromosome 1p. Using single-point analysis, the peak logarithm of odds (LOD) was 3.1 for marker D1S3669 (34.2 cM), whereas with multipoint analysis the peak LOD was 2.58 at 35 cM. No other areas of suggestive linkage were found. We propose that an area on chromosome 1 may harbor a gene or genes conferring susceptibility to diabetic retinopathy.

A method to predict the metabolic effects of changes in insulin treatment in subgroups of a large population based patient cohort

This case-control study was designed to analyse predictors of the effects on HbA1c levels in 4001 type 1 and type 2 diabetic patients after changing their insulin treatment. Patients from 15 outpatient diabetic clinics were treated with basal insulin and multiple injections of short-acting insulin. The effects on HbA1c of changing from NPH insulin to insulin glargine as basal insulin were studied, compared to patients continuing with NPH insulin. The following possible predictors were examined with multiple regression analysis: age, sex, type and duration of diabetes, smoking, metformin use, insulin requirement, number of basal doses per day, BMI and HbA1c at baseline. The difference between the two regression functions yielded the effect of switching treatment to insulin glargine compared to continuing with NPH insulin. Male gender, low BMI and high baseline HbA1c levels were significant predictors for a greater decrease in HbA1c when changing to insulin glargine. For example, for men with a BMI of 25 and an HbA1c of 8.0%, there was a calculated mean benefit in HbA1c of 0.26 percentage points by changing to insulin glargine, whereas women with a BMI 30 had no benefit of such a change. Thus, changing to insulin glargine had best effect in male patients with low BMI. This is one of the first studies designed to find responders to insulin treatment. Analyses of predictors may prove useful in order to tailor insulin treatment in diabetic patients in clinical practice. The clinical effects need to be confirmed in other studies and randomised controlled trials.

Six year incidence and progression of diabetic retinopathy: results from the Mauritius diabetes complication study

AIMS

To determine the incidence, progression and risk factors for diabetic retinopathy in the multiethnic population of Mauritius.

METHOD

A longitudinal, population-based study was conducted in Mauritius, during 1987, 1992 and 1998. Participants identified through the study as having diabetes (both known and newly diagnosed, by self-report and oral glucose tolerance test) and one in four participants with impaired glucose tolerance (IGT) underwent complications screening in 1992 and 1998. Retinal photographs were taken using a TRC-50VT retinal camera in three fields of the right eye (centred on the optic disc; macula (temporal to the optic disc); and nasal to disc). Photographs were graded according to a simplified version of the Wisconsin grading system.

RESULTS

The 6-year incidence of diabetic retinopathy was 23.8% (sight-threatening in 0.4%). Among those with known diabetes mellitus (KDM) and free of retinopathy at baseline the incidence of non-proliferative diabetic retinopathy (NPDR) was 29.2% and proliferative diabetic retinopathy (PDR) was 1.0%. Among those with newly diagnosed diabetes mellitus (NDM) at baseline the incidence of NPDR was 19.1% (no incident cases of PDR were found). Independent risk factors for retinopathy using the baseline population characteristics were duration of diabetes and fasting plasma glucose.

CONCLUSIONS

This is one of the few recent population-based studies of diabetic retinopathy undertaken in a developing nation. The incidence of retinopathy in Mauritius was high among those with NDM at baseline, with one in five developing retinopathy over 6 years. These results support the concept that screening for diabetes is important.

Prevalence of retinopathy in Caucasian type 2 diabetic patients from the South of Brazil and relationship with clinical and metabolic factors

Diabetic retinopathy (DR) is a sight-threatening chronic complication of diabetes mellitus and is the leading cause of acquired blindness in adults. In this cross-sectional study, we investigated the prevalence of and the factors associated with DR in an analysis of 210 consecutive and unrelated Brazilian Caucasians with type 2 diabetes mellitus. Retinopathy was evaluated by ophthalmoscopy and/or biomicroscopy through dilated pupils. The relationship between clinical and metabolic variables and the presence of DR was assessed by logistic regression analysis. DR was detected in 99 of the 210 patients (47%). In the univariate logistic regression analyses, male sex, duration of diabetes, body mass index, glycated hemoglobin, C-peptide, LDL cholesterol, smoking, and albumin excretion rate were found to be associated with the presence of DR. However, the multiple logistic regression analysis showed that only duration of diabetes (odds ratio (OR) = 1.15, 95% CI = 1.09-1.22; P < 0.001), glycated hemoglobin (OR = 1.21, 95% CI = 1.01-1.46; P = 0.047) and albumin excretion rate > 100 microg/min (OR = 12.72, 95% CI = 3.89-41.56; P < 0.001) were independently associated with DR. Although DR was found to be frequent among Brazilian type 2 diabetic patients, its prevalence was within the range observed in other Caucasian populations. Our findings emphasize the need for good glycemic control in order to prevent or delay the onset of DR, since the most well-known risk factors for the development of this complication in type 2 diabetes mellitus, such as duration of diabetes, glycated hemoglobin and albumin excretion rate were independently related to DR.

Patients with type 2 diabetes aged 35-64 years at four primary health care centres in Stockholm County, Sweden. Prevalence and complications in relation to gender and socio-economic status

This study estimates the prevalence of known diabetes, and complications of type 2 diabetes, among subjects aged 35-64 years, in relation to socio-economic factors and gender at four primary health care centres (PHCCs) in Stockholm County, Sweden. A total of 685 diabetic subjects aged 35-64 years of age were identified in primary care by diagnosis using electronic patient records. Data were supplied from medical records, and postal questionnaires. The prevalence of known diabetes among subjects aged 35-65 years differed between the PHCCs, with standardised rates between 1.7 and 3.6%, with the highest figure at the PHCC in an underprivileged area. The prevalence was higher among men (2.8% versus 1.7%). A subgroup of the patients, i.e. 389 subjects aged 35-64 years with type 2 diabetes, was studied with regard to complications. Higher education level was protective for microvascular complications (OR 0.50; CI 0.25-1.00). In addition, microvascular complications were predicted by male sex, duration, HbA(1c), and hypertension, and macrovascular complications by male sex, age, and hypertension. Prevalence of known diabetes and microvascular complications in type 2 diabetes, are associated with lower socio-economic status and male sex.

Longitudinal studies of incidence and progression of diabetic retinopathy assessed by retinal photography in pima indians

OBJECTIVE

To examine incidence and progression of retinopathy using retinal photographs in Pima Indians and to compare the results with those obtained when retinopathy is assessed by direct ophthalmoscopy.

RESEARCH DESIGN AND METHODS

We undertook an analysis of examinations conducted between 1 April 1982 and 31 December 1990 in residents of the Gila River Community in central Arizona. Data were taken from 411 people with diabetes who had at least two examinations during this period. Incidence and progression of retinopathy were evaluated by retinal photography and fundoscopy, and hazard rate ratios were calculated for various potential risk factors measured at baseline.

RESULTS

Previously diagnosed retinopathy tended to progress, except in individuals with minimal nonproliferative retinopathy, among whom follow-up examinations were more likely to show no retinopathy. Diabetes duration (hazard rate ratio [HRR], 1.06 per year difference [P = 0.007]), hyperglycemia (HbA(1) HRR, 1.27 per 1% difference [P < 0.0001]), the type of treatment for diabetes (insulin use HRR, 3.06 [P = 0.0007], and oral hypoglycemic use HRR, 2.40 [P = 0.0034], compared with individuals on no pharmacotherapy), and macroalbuminuria (HRR, 2.86, compared with individuals without macroalbuminuria [P = 0.0486]) were associated with the development of retinopathy. Although fundoscopy detected fewer cases of retinopathy, HRRs for most risk factors were similar when retinopathy was assessed by fundoscopy rather than retinal photography.

CONCLUSIONS

Although retinopathy tends to worsen over time, some eyes show improvement, especially in patients with minimal nonproliferative retinopathy. As in other populations, glycemic control is the major modifiable risk factor for the development and progression of retinopathy.