The appearance of retinopathy and progression to proliferative retinopathy: the WHO Multinational Study of Vascular Disease in Diabetes

Blood pressure control for diabetic retinopathy

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Prognostic factors for the development and progression of proliferative diabetic retinopathy in people with diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) is characterised by neurovascular degeneration as a result of chronic hyperglycaemia. Proliferative diabetic retinopathy (PDR) is the most serious complication of DR and can lead to total (central and peripheral) visual loss. PDR is characterised by the presence of abnormal new blood vessels, so-called "new vessels," at the optic disc (NVD) or elsewhere in the retina (NVE). PDR can progress to high-risk characteristics (HRC) PDR (HRC-PDR), which is defined by the presence of NVD more than one-fourth to one-third disc area in size plus vitreous haemorrhage or pre-retinal haemorrhage, or vitreous haemorrhage or pre-retinal haemorrhage obscuring more than one disc area. In severe cases, fibrovascular membranes grow over the retinal surface and tractional retinal detachment with sight loss can occur, despite treatment. Although most, if not all, individuals with diabetes will develop DR if they live long enough, only some progress to the sight-threatening PDR stage.  OBJECTIVES: To determine risk factors for the development of PDR and HRC-PDR in people with diabetes and DR.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2022, Issue 5), Ovid MEDLINE, and Ovid Embase. The date of the search was 27 May 2022. Additionally, the search was supplemented by screening reference lists of eligible articles. There were no restrictions to language or year of publication.  SELECTION CRITERIA: We included prospective or retrospective cohort studies and case-control longitudinal studies evaluating prognostic factors for the development and progression of PDR, in people who have not had previous treatment for DR. The target population consisted of adults (≥18 years of age) of any gender, sexual orientation, ethnicity, socioeconomic status, and geographical location, with non-proliferative diabetic retinopathy (NPDR) or PDR with less than HRC-PDR, diagnosed as per standard clinical practice. Two review authors independently screened titles and abstracts, and full-text articles, to determine eligibility; discrepancies were resolved through discussion. We considered prognostic factors measured at baseline and any other time points during the study and in any clinical setting. Outcomes were evaluated at three and eight years (± two years) or lifelong.  DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data from included studies using a data extraction form that we developed and piloted prior to the data collection stage. We resolved any discrepancies through discussion. We used the Quality in Prognosis Studies (QUIPS) tool to assess risk of bias. We conducted meta-analyses in clinically relevant groups using a random-effects approach. We reported hazard ratios (HR), odds ratios (OR), and risk ratios (RR) separately for each available prognostic factor and outcome, stratified by different time points. Where possible, we meta-analysed adjusted prognostic factors. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.   MAIN RESULTS: We screened 6391 records. From these, we identified 59 studies (87 articles) as eligible for inclusion. Thirty-five were prospective cohort studies, 22 were retrospective studies, 18 of which were cohort and six were based on data from electronic registers, and two were retrospective case-control studies. Twenty-three studies evaluated participants with type 1 diabetes (T1D), 19 with type 2 diabetes (T2D), and 17 included mixed populations (T1D and T2D). Studies on T1D included between 39 and 3250 participants at baseline, followed up for one to 45 years. Studies on T2D included between 100 and 71,817 participants at baseline, followed up for one to 20 years. The studies on mixed populations of T1D and T2D ranged from 76 to 32,553 participants at baseline, followed up for four to 25 years.  We found evidence indicating that higher glycated haemoglobin (haemoglobin A1c (HbA1c)) levels (adjusted OR ranged from 1.11 (95% confidence interval (CI) 0.93 to 1.32) to 2.10 (95% CI 1.64 to 2.69) and more advanced stages of retinopathy (adjusted OR ranged from 1.38 (95% CI 1.29 to 1.48) to 12.40 (95% CI 5.31 to 28.98) are independent risk factors for the development of PDR in people with T1D and T2D. We rated the evidence for these factors as of moderate certainty because of moderate to high risk of bias in the studies.  There was also some evidence suggesting several markers for renal disease (for example, nephropathy (adjusted OR ranged from 1.58 (95% CI not reported) to 2.68 (2.09 to 3.42), and creatinine (adjusted meta-analysis HR 1.61 (95% CI 0.77 to 3.36)), and, in people with T1D, age at diagnosis of diabetes (< 12 years of age) (standardised regression estimate 1.62, 95% CI 1.06 to 2.48), increased triglyceride levels (adjusted RR 1.55, 95% CI 1.06 to 1.95), and larger retinal venular diameters (RR 4.28, 95% CI 1.50 to 12.19) may increase the risk of progression to PDR. The certainty of evidence for these factors, however, was low to very low, due to risk of bias in the included studies, inconsistency (lack of studies preventing the grading of consistency or variable outcomes), and imprecision (wide CIs). There was no substantial and consistent evidence to support duration of diabetes, systolic or diastolic blood pressure, total cholesterol, low- (LDL) and high- (HDL) density lipoproteins, gender, ethnicity, body mass index (BMI), socioeconomic status, or tobacco and alcohol consumption as being associated with incidence of PDR. There was insufficient evidence to evaluate prognostic factors associated with progression of PDR to HRC-PDR.  AUTHORS' CONCLUSIONS: Increased HbA1c is likely to be associated with progression to PDR; therefore, maintaining adequate glucose control throughout life, irrespective of stage of DR severity, may help to prevent progression to PDR and risk of its sight-threatening complications. Renal impairment in people with T1D or T2D, as well as younger age at diagnosis of diabetes mellitus (DM), increased triglyceride levels, and increased retinal venular diameters in people with T1D may also be associated with increased risk of progression to PDR. Given that more advanced DR severity is associated with higher risk of progression to PDR, the earlier the disease is identified, and the above systemic risk factors are controlled, the greater the chance of reducing the risk of PDR and saving sight.

Association of Generalized and Abdominal Obesity with Diabetic Retinopathy in Chinese Type 2 Diabetic Patients

AIMS

Obesity has been proposed to promote the progression of diabetic retinopathy (DR), but previous studies have not shown consistent results. We aimed to explore the association between generalized and abdominal obesity and DR risk, and to assess the joint effect of these two different types of obesity on DR development.

METHODS

A nested case-control study within a large prospective study on type 2 diabetes was conducted in communities in Huai'an City, Jiangsu Province, China. Cases were individuals who had diagnoses of DR during the 6-year follow-up. A total number of 1544 DR cases and 1:1 matched controls were included. Binomial and multinomial logistic regression models were used to investigate the effects of obesity on DR occurrence and DR severity.

RESULTS

Compared with individuals in the first tertile of the baseline waist-to-hip ratio (WHR), subjects in the third tertile at baseline had significantly higher risk of DR (OR 1.44, 95% CI 1.17-1.78) during the follow-up period. Conversely, body mass index (BMI) (continuous) had an adjusted OR of 0.97 (95% CI 0.95-0.99) of developing DR. Individuals with low BMI and high WHR levels were identified as a high-risk population with a higher likelihood of developing DR (OR 1.65, 95% CI 1.17-2.33) than those in the lowest BMI category and simultaneously in the first WHR tertile.

CONCLUSIONS

Type 2 diabetic individuals with low BMI levels and high WHR levels had a significantly increased risk of developing DR which indicated that isolated abdominal obesity might be involved in the pathogenesis of DR.

The Prevalence and Risk Factors of Diabetic Retinopathy: Screening and Prophylaxis Project in 6 Provinces of China

PURPOSE

To investigate the prevalence and associated factors of diabetic retinopathy (DR) and advanced DR in Chinese adults with diabetes mellitus (DM).

PATIENTS AND METHODS

A cross-sectional study was performed on 4831 diabetic patients from 24 hospitals from April 2018 to July 2020. Non-mydriatic fundus of patients were interpreted by an artificial intelligence (AI) system. Fundus photos that were unsuitable for AI interpretation were interpreted by two ophthalmologists trained by one expert ophthalmologist at Beijing Tongren Hospital. Medical history, height, weight, body mass index (BMI), glycosylated hemoglobin (HbA1c), blood pressure, and laboratory examinations were recorded.

RESULTS

A total of 4831 DM patients were included in this study. The prevalence of DR and advanced DR in the diabetic population was 31.8% and 6.6%, respectively. In multiple logistic regression analysis, male (odds ratio [OR], 1.39), duration of diabetes (OR, 1.05), HbA1c (OR, 1.11), farmer (OR, 1.39), insulin treatment (OR, 1.61), region (northern, OR, 1.78; rural, OR, 6.96), and presence of other diabetic complications (OR: 2.03) were associated with increased odds of DR. The factors associated with increased odds of advanced DR included poor glycemic control (HbA1c >7.0%) (OR, 2.58), insulin treatment (OR, 1.73), longer duration of diabetes (OR, 3.66), rural region (OR, 4.84), and presence of other diabetic complications (OR, 2.36), but overweight (BMI > 25 kg/m²) (OR, 0.61) was associated with reduced odds of advanced DR.

CONCLUSION

This study shows that the prevalence of DR is very high in Chinese adults with DM, highlighting the necessity of early diabetic retinal screening.

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.

Mechanisms and early patterns of dyslipidemia in pediatric type 1 and type 2 diabetes

Objectives The is no consensus on the early patterns of lipid-based cardiovascular disease (CVD) risk in youth with either type 1 diabetes (T1D) or type 2 diabetes (T2D). The aim was todetermine the differences in CVD risk, using lipid profiles, in children and adolescents with either T1D or T2D at the time of their first lipid assessment, after stratifying the T1D cohort into remitters and non-remitters based on their honeymoon history. Methods A cross-sectional study of 249 subjects consisting of 73 controls, 53 T2D subjects, and 123 T1D subjects stratified into remitters (n=44), and non-remitters (n=79). Partial clinical remission (PCR) was defined as insulin-dose adjusted HbA1c of ≤9. Pubertal status was determined by Tanner staging. Results After adjusting for age, sex, BMI, race, and pubertal status, T2D patients had significantly higher LDL-C compared to the controls (p=0.022), the remitters (p=0.029), but not the non-remitters (103.1 ± 5.9 mg/dL vs. 91.4 ± 4.2 mg/dL, p=0.49). Similarly, T2D patients had significantly higher non-HDL-C compared to the controls (p=0.006), the remitters (p=0.0002), but not the non-remitters (137.6 ± 7.1 mg/dL vs. 111.71 ± 5.0 mg/dL, p=0.053). Total cholesterol was also significantly higher in T2D patients compared to the controls (p=0.0005), the remitters (p=0.006) but not the non-remitters (183.5 ± 6.6 mg/dL vs. 166.2 ± 4.8 mg/dL, p=0.27). Conclusions Lack of the honeymoon phase in children and adolescents with T1D confers early and significantly increased lipid-based cardiovascular risk to these patients that is similar to the elevated cardiovascular risk seen in T2D.

Risk factors for retinopathy in hemodialysis patients with type 2 diabetes mellitus

There is limited knowledge on the prevalence and risk factors of diabetic retinopathy (DR) in dialysis patients. We have investigated the association between diabetes mellitus and lipid-related biomarkers and retinopathy in hemodialysis patients. We reviewed 1,255 hemodialysis patients with type 2 diabetes mellitus (T2DM) who participated in the German Diabetes and Dialysis Study (4D Study). Associations between categorical clinical, biochemical variables and diabetic retinopathy were examined by logistic regression. On average, patients were 66 ± 8 years of age, 54% were male and the HbA1c was 6.7% ± 1.3%. DR, found in 71% of the patients, was significantly and positively associated with fasting glucose, HbA1c, time on dialysis, age, systolic blood pressure, body mass index and the prevalence of other microvascular diseases (e.g. neuropathy). Unexpectedly, DR was associated with high HDL cholesterol and high apolipoproteins AI and AII. Patients with coronary artery disease were less likely to have DR. DR was not associated with gender, smoking, diastolic blood pressure, VLDL cholesterol, triglycerides, and LDL cholesterol. In summary, the prevalence of DR in patients with type 2 diabetes mellitus requiring hemodialysis is higher than in patients suffering from T2DM, who do not receive hemodialysis. DR was positively related to systolic blood pressure (BP), glucometabolic control, and, paradoxically, HDL cholesterol. This data suggests that glucose and blood pressure control may delay the development of DR in patients with diabetes mellitus on dialysis.

Associations between abdominal obesity indices and diabetic complications: Chinese visceral adiposity index and neck circumference

Background and aims

Obesity, especially abdominal obesity, has been considered a risk factor for diabetic complications. Many abdominal obesity indices have been established, including neck circumference (NC), waist-to-hip ratio (WHR), lipid accumulation product (LAP), visceral adiposity index (VAI) and the Chinese visceral adiposity index (CVAI). However, studies investigating the associations between these indices and diabetic complications are limited. The objective of this study was to investigate the associations of the abdominal obesity indices with cardiovascular and cerebrovascular disease (CVD), diabetic kidney disease (DKD) and diabetic retinopathy (DR).

Methods

A total of 4658 diabetic participants were enrolled from seven communities in Shanghai, China, in 2018. Participants completed questionnaires and underwent blood pressure, glucose, lipid profile, and urine albumin/creatinine ratio measurements; fundus photographs; and anthropometric parameters, including height, weight, waist circumference (WC), NC and hip circumference (HC).

Results

In men, a one standard deviation (SD) increase in CVAI level was significantly associated with a greater prevalence of CVD (OR 1.35; 95% CI 1.13, 1.62) and DKD (OR 1.38; 95% CI 1.12, 1.70) (both P < 0.05). In women, a one SD increase in CVAI level was significantly associated with a greater prevalence of CVD (OR 1.32; 95% CI 1.04, 1.69) and DKD (OR 2.50; 95% CI 1.81, 3.47) (both P < 0.05). A one SD increase in NC was significantly associated with a greater prevalence of CCA plaque in both men (OR 1.26; 95% CI 1.10, 1.44) and women (OR 1.20; 95% CI 1.07, 1.35). These associations were all adjusted for potential confounding factors.

Conclusions

CVAI was most strongly associated with the prevalence of CVD and DKD among the abdominal obesity indices, and NC was unique associated with the prevalence of CCA plaque in Chinese adults with diabetes.

Trial registration ChiCTR1800017573, www.chictr.org.cn. Registered 04 August 2018.

Early Diabetic Nephropathy and Retinopathy in Patients with Type 1 Diabetes Mellitus Attending Sudan Childhood Diabetes Centre

OBJECTIVE

Data on microvascular complications in children and adolescents with type 1 diabetes mellitus (T1DM) in Sudan are scarce. This study was aimed at determining the prevalence of diabetic nephropathy (DN) and retinopathy (DR) and their relationship to certain risk factors in children with T1DM attending the Sudan Childhood Diabetes Centre. Design and Methods. A clinic-based cross-sectional study of 100 patients with T1DM aged 10-18 years. Patients with disease duration exceeding 5 years if the onset of diabetes was prepubertal and 2 years if it was postpubertal were included. Relevant sociodemographic, clinical, and biochemical information was obtained. Blood pressure was measured. The patients were screened for DN and DR using urinary microalbumin estimation and fundus photography, respectively.

RESULTS

The frequency of microalbuminuria and diabetic retinopathy was 36% and 33%, respectively. Eleven percent had both retinopathy and microalbuminuria. Seven percent of the patients were found to be hypertensive. Patients with diabetic retinopathy had significantly higher HbA1c levels (p = 0.009) and longer diabetes duration (p = 0.02) than patients without retinopathy. Logistic regression showed that high HbA1c (odds ratio (OR) 0.83, confidence interval (CI) 0.68-1.00, p = 0.04), but not age, duration, ethnic group, BMI, blood pressure, and presence of nephropathy, was an independent risk factor for retinopathy. Likewise, high blood pressure (OR 6.89, CI 1.17-40.52, p = 0.03), but not age, duration, ethnic group, BMI, HbA1c, and presence of retinopathy, was a predictor for nephropathy.

CONCLUSION

High prevalence of incipient DN and early stages of DR were observed in this study. Longer diabetes duration and higher HbA1c were associated with the presence of diabetic retinopathy. High blood pressure was a risk factor for DN. So regular screening for these complications and optimization of glycemic control are needed.

The prevalence of retinopathy among type 2 diabetic patients in Iran: A systematic review and meta-analysis

Diabetic retinopathy is one of the most major causes of blindness and disability in diabetic patients and imposes very high cost on Health Care System. Studies conducted in the country showed different and inconsistent prevalence of the disease. The study aims to determine the overall prevalence of retinopathy in patients with type 2 diabetes in Iran through a systematic review and meta-analysis. The present study was conducted via meta-analysis method during March, 2000 to October, 2018. The articles related to the subject under study were obtained from Magiran, SID, Medline (PubMed), Science Direct, Scopus and Google Scholar databases. I2 index was used to examine the heterogeneity of articles studied; and the data was analyzed by Comprehensive Meta-Analysis Software. Through the study of 34 articles and 17,079 individuals with age range of 5-83, the overall prevalence of retinopathy for type 2 diabetic patients in Iran and on the basis of meta-analysis, was obtained that was 37.8% (32.84-43%, 95% confidence interval); the highest prevalence of retinopathy for type 2 diabetic patients was in Tehran province with 78% (68.8-85.1%, 95% confidence interval) in 2006 and the lowest prevalence of retinopathy for type 2 diabetic patients was in Isfahan province with 9% (7.1-11.4, 95% confidence interval) in 2006; furthermore, the prevalence of retinopathy for type 2 diabetic patients in Iran increases with increased sample size that it was statistically significant (P < 0.05). Regarding the high prevalence of retinopathy for type 2 diabetic patients in the country, it is essential that health policy makers take effective measures to reduce the disease incidence in diabetic patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Increased serum periostin concentrations are associated with the presence of diabetic retinopathy in patients with type 2 diabetes mellitus

PURPOSE

To determine the association between serum periostin and the presence of diabetic retinopathy (DR).

METHODS

Serum periostin was detected in 114 healthy subjects, 122 patients with type 2 diabetes mellitus (T2DM) and 159 patients with DR and compared among groups. Clinical data and other laboratory measurements such as glycated hemoglobin (HbA1c), lipid profiles, serum creatinine (Cr) and high-sensitivity CRP (hsCRP) were also collected and compared among groups. For subgroup analysis, patients with DR were divided into a non-proliferated diabetic retinopathy (NPDR) group and a proliferated diabetic retinopathy (PDR) group. Multivariate analysis was performed using logistic regression models.

RESULTS

The serum periostin level was significantly higher in patients with diabetic retinopathy compared with healthy subjects and patients with T2DM (both P < 0.001, respectively). Also, the periostin level was significantly higher in the PDR group compared to the NPDR group (P = 0.044). Multivariate logistic regression revealed that serum periostin was independently associated with the presence of DR in patients with T2DM (P < 0.001). The receiver operating characteristic (ROC) curves for DR development using serum periostin showed that the area under the receiver operating characteristic curves (AUC) was 0.838 (P < 0.001).

CONCLUSIONS

The current study demonstrated that serum periostin is significantly associated with the presence of DR in patients with T2DM and is an independent risk factor of DR.

Is there a relationship between body mass index and diabetic retinopathy in type II diabetic patients? A cross sectional study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is one of the most important leading causes of disability, premature mortality and Diabetic Retinopathy (DR) that is one of the diabetes-related complications in diabetic patients and the most common cause of vision loss in diabetic patients. The aim of the study was to evaluate the association between DR and body mass index (BMI) in those patients with T2DM.

METHODS

This was a central-based, cross-sectional study on 518 diabetic patients. Their medical history and the laboratory data were collected. All the patients received examination of diabetic retinopathy by professional ophthalmologist. Based on their optic fundi findings, they were classified into five groups: No retinopathy, Mild Non-proliferative Diabetic Retinopathy (NPDR), Moderate NPDR, Severe NPDR, Proliferative diabetic retinopathy (PDR). To analysis data SPSS v18 software used. Frequency, percent, mean and standard deviation were used for population description. t test, spearman correlation, partial correlation, analysis of variance (ANOVA) and Chi-square test (χ2) were used for analytic analysis. Multivariate logistic regression was used to estimate the odds ratio.

RESULTS

518 patients with T2DM 198 male (38%), 320 female (62%) included in this study. The mean age of patients was 61.02 ± 10.18 years. The mean age at onset was 49.06 + 10.52 years and the mean duration of diabetes was 12.09 ± 7.81 years. There was a strong relationship between duration of diabetes and DR (P = 0.001). There were strong significant association between the development of DR and Insulin therapy (OR = 5.975). Correlation analysis between Retinopathy and BMI showed that BMI had inverse relationship with DR when BMI considered as a continuous variable (p-value = 0.009 and correlation coefficient = -0.467).

CONCLUSION

BMI in diabetic patient is one of the most important clinical parameter for their health and disease progression. We conclude that BMI had inverse relationship with DR when BMI considered as a continuous variable.

Influence of remission and its duration on development of early microvascular complications in young adults with type 1 diabetes

INTRODUCTION

Prevalence of partial remission ranges between 20% and 80% in the initial course of type 1 diabetes. In this phase of the disease, a substantial insulin secretion contributes to good metabolic control. The aim of the study was to determine the association between presence of partial remission and occurrence of microangiopathy complications in type 1 diabetes.

MATERIAL AND METHODS

Ninety-eight consecutive patients with newly diagnosed type 1 diabetes were asked to participate in a cohort study. Partial remission was defined as the time in which all of the following criteria were met: HbA1c below 6.5% (48mmol/mol), daily insulin requirement below 0.3 U/kg body weight and serum Cpeptide concentration above 0.5ng/ml. Patients were divided into those who were in remission at any time during follow-up (remitters) and non-remitters. After 7years of follow-up, the occurrence of microangiopathy complications was analyzed. In statistical analysis, Mann-Whitney test, chi(2) test and Fisher test were used for analysis between groups. We applied a Cox's multivariate regression model and univariate regression method. P<0.05 was considered statistically significant.

RESULTS

In univariate logistic regression, a significant association was found between absence of remission and occurrence of at least one microvascular complication. In the Cox proportional hazards regression model that included clinically significant parameters at diagnosis (presence of ketoacidosis, cigarette smoking and HbA1c value) as covariates, absence of remission was associated with occurrence of chronic complications of diabetes at 7years [HR: 3.65 (95% CI 1.23-4.56), p=0.04]. In non-remitters, higher incidence of at least one microvascular complication (46.4% vs. 7.6%), higher incidence of retinopathy (42.8% vs. 5.7%), and neuropathy (21.4% vs. 1.9%) was found.

CONCLUSIONS

Occurrence of partial remission of diabetes is associated with a reduced risk of chronic microvascular complications at 7-year follow-up.

Association between body mass index and diabetic retinopathy in Chinese patients with type 2 diabetes

AIMS

To explore the factors mediating the relationship between body mass index (BMI) and diabetic retinopathy (DR) in Chinese type 2 diabetes patients.

METHODS

This is a cross-sectional study. Data of 2,533 patients with type 2 diabetes were studied from the Shanghai Diabetes Registry Database. DR was assessed using non-mydriatic fundus photography and graded as non-DR, mild-moderate (DR I-II), and sight-threatening (DR III-IV). BMI (kg/m(2)) was classified as normal weight (18.5 ≤ BMI < 25), overweight (25 ≤ BMI < 30), and obese (BMI ≥ 30). β cell function was evaluated by fasting C-peptide (FCP).

RESULTS

DR was present in 701 (27.7 %) patients. Patients with DR had lower BMI (24.3 vs. 24.9 kg/m(2), P = 0.001) and fasting C-peptide (1.46 vs. 1.86 ng/ml, P < 0.001) than those without DR. The association between BMI (2 kg/m(2) interval) and DR was U-shaped; patients with BMI 28-29.9 kg/m(2) had the lowest DR rate. Compared with normal weight, overweight was associated with reduced risk of any DR [odds ratio (OR) 0.73], DR I-II (OR 0.76), and DR III-IV (OR 0.64) after adjustment for sex, age at diabetes diagnosis, and duration of diabetes. This negative association attenuated after adjustment for other confounders and became nonsignificant after further adjustment for FCP. Patients with different BMI categories had similar DR risk when stratified by FCP tertiles.

CONCLUSION

Overweight patients have lower DR prevalence than normal weight individuals, which may be attributable to better β cell function in overweight patients.

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

BACKGROUND

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

OBJECTIVE

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

SUBJECTS AND METHODS

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

RESULTS

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

CONCLUSION

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

The Prevalence of Age-Related Eye Diseases and Cataract Surgery among Older Adults in the City of Lodz, Poland

Purpose. To determine the prevalence of age-related eye diseases and cataract surgery among older adults in the city of Lodz, in central Poland. Material and Methods. The study design was cross-sectional and observational study. A total of 1107 women and men of predominantly Caucasian origin were successfully enumerated and recruited for the study. All selected subjects were interviewed and underwent detailed ophthalmic examinations. Results. Overall 8.04% (95% CI 6.44-9.64) subjects had cataract surgery in either eye. After excluding subjects with bilateral cataract surgery, the prevalence of cataract was 12.10% (95% CI 10.18-14.03). AMD was found in 4.33% (95% CI 3.14-5.54 ) of all subjects. Of them 3.25% (95% CI 2.21-4.30 ) had early AMD and 1.08% (95% CI 0.47-1.69) had late AMD. Various types of glaucoma were diagnosed in 5.51% (95% CI 4.17-6.85) of subjects and 2.62% (95% CI 1.68-3.56) had OHT. The prevalence rates of DR and myopic macular degeneration were 1.72% (95% CI 0.95-2.48) and 0.45% (95% CI 0.06-0.85), respectively. All multiple logistic regression models were only significantly associated with older age. The highest rate of visual impairment was observed among subjects with retinal diseases. Conclusions. The study revealed high prevalence of age-related eye diseases in this older population.

Blood pressure control for diabetic retinopathy

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Rapid assessment of avoidable blindness and diabetic retinopathy in Republic of Moldova

OBJECTIVE

To evaluate the prevalence and causes of blindness and visual impairment, the prevalence of diabetes mellitus and diabetic retinopathy among people aged ≥50 years in the Republic of Moldova using Rapid Assessment of Avoidable Blindness plus Diabetic Retinopathy ('RAAB+DR') techniques.

MATERIALS AND METHODS

111 communities of people aged ≥50 years were randomly selected. In addition to standard RAAB procedures in all people with diabetes (previous history of the disease or with a random blood glucose level >11.1 mm/L (200 mg/dL)), a dilated fundus examination was performed to assess the presence and the degree of diabetic retinopathy using the Scottish DR grading system.

RESULTS

3877 (98%) people out of the 3885 eligible people were examined. The prevalence of blindness was 1.4% (95% CI 1.0% to 1.8%). The major causes of blindness and severe visual impairment were untreated cataract (58.2%), glaucoma (10.9%), and other posterior segment causes (10.9%). The estimated prevalence of diabetes was 11.4%. Among all people with diabetes, 55.9% had some form of retinopathy, and sight threatening diabetic retinopathy affected 14.6%.

CONCLUSIONS

The RAAB+DR survey in the Republic of Moldova established that untreated cataract is the major cause of avoidable blindness in rural areas. This needs to be tackled by expanding the geographical coverage of cataract surgical services.

Triglyceride-high-density lipoprotein cholesterol is associated with microvascular complications in type 2 diabetes mellitus

The purpose of this study was to evaluate whether a high triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio is associated with an increased incidence of retinopathy and chronic kidney disease (CKD) in type 2 diabetes mellitus. Individuals with type 2 diabetes mellitus (n = 979) with an estimated glomerular filtration rate greater than 60 mL/min and without retinopathy and cardiovascular disease at baseline were followed up for the incidence of diabetic retinopathy (diagnosed by retinography) and CKD (diagnosed by estimated glomerular filtration rate ≤60 mL/min/1.73 m(2)). On follow-up (mean, 4.9 years), 217 (22.2% of total) subjects experienced CKD and/or diabetic-specific retinal lesions (microvascular complication). Of these, 111 subjects developed isolated retinopathy, 85 developed CKD alone, and 21 developed both complications. The TG/HDL-C ratio was positively associated with an increased risk of incident retinopathy and/or CKD (composite microvascular end point) independently of age, sex, body mass index, diabetes duration, hemoglobin A(1c), hypertension, smoking history, low-density lipoprotein cholesterol, albuminuria, and current use of hypoglycemic, antihypertensive, lipid-lowering, or antiplatelet drugs (multivariable-adjusted odds ratio, 2.15; 95% confidence intervals, 1.10-4.25; P = .04). These findings suggested that the TG/HDL-C ratio was associated with an increased incidence of microvascular complications in individuals with type 2 diabetes mellitus without prior cardiovascular disease, independently of several potential confounders.

Epidemiology of major eye diseases leading to blindness in Europe: a literature review

The objective of this work was to study the epidemiology of major eye diseases leading to blindness in Europe through a systematic literature review. The literature search was performed using the Medline database (PubMed), with MeSH and free text search terms. Inclusion criteria for the studies were: (a) performed on a healthy population of Caucasian origin aged between 50 and 75 years; (b) diagnosed by ophthalmological examination in accordance with the International Classification of Diseases 10; (c) contained a detailed description of the sampling and diagnostic procedures and data resources; (d) sample size>500, and (e) published between 1990 and 2008. The results of 57 studies on the prevalence and incidence of age-related macular degeneration, diabetic retinopathy and glaucoma are reported, providing an up-to-date and comprehensive overview of these diseases in Europe from an epidemiological perspective.

Dyslipidemia and eye diseases in the adult Chinese population: the Beijing eye study

To determine associations between dyslipidemia and ocular diseases, the population-based Beijing Eye Study 2006 examined 3251 subjects (age≥45 years) who underwent a detailed ophthalmic examination and biochemical blood analysis. Dyslipidemia was defined as any of the following: hypercholesterolemia (total cholesterol concentration≥5.72 mmol/L (220 mg/dL)) or hypertriglyceridemia (triglyceride concentration≥1.70 mmol/L (150 mg/dL)) or low high-density lipoprotein-cholesterol (HDL-C concentration≤0.91 mmol/L (35 mg/dL)). Biochemical blood examinations were available for 2945 (90.6%) subjects. After adjustment for age, gender, habitation region, body mass index, self reported income, blood glucose concentration, diastolic blood pressure and smoking, dyslipidemia was significantly associated with higher intraocular pressure (P<0.001) and beta zone of parapapillary atrophy (P = 0.03). Dyslipidemia was not significantly associated with the prevalence of glaucoma (P = 0.99), retinal vein occlusions (P = 0.92), diabetic retinopathy (P = 0.49),presence of retinal vascular abnormalities such as focal or general arteriolar narrowing, age-related macular degeneration(P = 0.27), nuclear cataract (P = 0.14), cortical cataract (P = 0.93), and subcapsular cataract (P = 0.67). The results make one conclude that, controlled for systemic and socioeconomic parameters, dyslipidemia was not associated with common ophthalmic disorders including glaucoma and age-related macular degeneration.

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

AIMS/HYPOTHESIS

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

METHODS

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

RESULTS

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

CONCLUSIONS/INTERPRETATION

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

The global burden of diabetes and its complications: an emerging pandemic

The number of patients with type 2 diabetes is increasing rapidly in both developed and developing countries around the world. The emerging pandemic is driven by the combined effects of population ageing, rising levels of obesity and inactivity, and greater longevity among patients with diabetes that is attributable to improved management. The vascular complications of type 2 diabetes account for the majority of the social and economic burden among patients and society more broadly. This review summarizes the burden of type 2 diabetes, impaired glucose tolerance, and their vascular complications. It is projected that by 2025 there will be 380 million people with type 2 diabetes and 418 million people with impaired glucose tolerance. Diabetes is a major global cause of premature mortality that is widely underestimated, because only a minority of persons with diabetes dies from a cause uniquely related to the condition. Approximately one half of patients with type 2 diabetes die prematurely of a cardiovascular cause and approximately 10% die of renal failure. Global excess mortality attributable to diabetes in adults was estimated to be 3.8 million deaths.

Effect of trandolapril on regression of retinopathy in hypertensive patients with type 2 diabetes: a prespecified analysis of the benedict trial

Background. The effect of angiotensin converting enzyme inhibitors (ACEi) on regression of retinopathy in type 2 diabetics is still ill defined. Methods. We compared the incidence of retinopathy regression in 90 hypertensive type 2 diabetics randomized to at least 3-year blinded ACEi with trandolapril (2 mg/day) or non-ACEi therapy who had preproliferative or proliferative retinopathy at baseline. Results. Over a median (interquartile range) follow-up period of 35.8 (12.4–60.7) months, retinopathy regressed in 27 patients (30.0%). Regression occurred in 18 of 42 patients (42.9%) on ACEi and in 9 of 48 (18.8%) on non-ACEi therapy (adjusted for predefined baseline covariates HR (95% CI): 2.75 (1.18–6.42), P = .0193). Concomitant treatment with or without Non-Dihydropyridine Calcium Channel Blockers (ndCCBs) did not appreciably affect the incidence of retinopathy regression. Conclusions. Unlike ndCCB, ACEi therapy may have an additional effect to that of intensified BP and metabolic control in promoting regression of diabetic retinopathy.

The geoepidemiology of type 1 diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by absolute insulin deficiency resulting from the progressive immune-mediated destruction of pancreatic islet beta cells. It is thought to be triggered by as yet unidentified environmental factors in genetically susceptible individuals, the major genetic contribution coming from loci within the HLA complex, in particular HLA class II. The worldwide incidence of T1D varies by at least 100-fold, being highest in Finland and Sardinia (Italy) and lowest in Venezuela and China. The incidence has been increasing worldwide at an annual rate of approximately 3%. While genetic factors are thought to explain some of the geographic variability in T1D occurrence, they cannot account for its rapidly increasing frequency. Instead, the declining proportion of newly diagnosed children with high-risk genotypes suggests that environmental pressures are now able to trigger T1D in genotypes that previously would not have developed the disease during childhood. Although comparisons between countries and regions with low and high-incidence rates have suggested that higher socioeconomic status and degree of urbanization are among the environmental factors that play a role in the rising incidence of T1D, the findings are too inconsistent to allow firm conclusions. Morbidity and mortality as well as causes of death also show considerable geographic variation. While glycemic control has been identified as a major predictor of the micro- and macrovascular complications of T1D and shows considerable geographical variability, it does not appear to be the only factor involved in the regional differences in complication rates. The role of genetics in susceptibility to nephropathy, retinopathy and other diabetic complications largely remains to be explored.

Six-year retrospective follow-up study of safe screening intervals for sight-threatening retinopathy in patients with diabetes mellitus

BACKGROUND

We estimate safe screening intervals for sight-threatening diabetic retinopathy (STDR).

METHODS

A 6-year retrospective follow-up study to review screening results of two cohorts of patients with diabetes mellitus (DM) was conducted; a cohort free of diabetic retinopathy (DR) and a cohort with mild nonproliferative diabetic retinopathy (NPDR) at baseline. Patients had been screened by means of a nonmydriatic retinal camera. Baseline age, sex, and diabetes characteristics were also collected. Statistical analysis was based on life-table method of risk estimation.

RESULTS

A total of 286 patients with DM free of DR and 144 patients with mild NPDR at baseline were included in the study. For patients free of DR, the probability of remaining free of STDR was 97% (95% confidence interval [CI] 94-99%) at the end of the fourth year. In this cohort of patients, those with type 2 DM were more likely to progress to STDR than those who had type 1 DM (p < .01). For patients with mild NPDR, the probability of remaining free of STDR dropped to 94% (95% CI 88-97%) at the end of the second year, and it was still 100% at the end of the second year for those with a glycated hemoglobin level < or =7.5% at baseline (p < .05).

CONCLUSIONS

Screening at a 3-4 year interval for diabetes patients free of DR is safe because of their low risk of developing STDR. Patients with mild NPDR require screening at a 1 year interval, or at a 2 year interval with good metabolic control.

Retinal vascular signs in diabetes and hypertension--review

The retinal vasculature is a unique site where the microcirculation can be noninvasively imaged in vivo. This presents an opportunity to study otherwise inaccessible structural features of the microcirculation. Recently, a number of population-based studies have developed quantitative methods of measuring these retinal signs, and investigated how these signs relate to metabolic disorders such as diabetes, hypertension, obesity, and metabolic syndrome. These studies have reported fairly consistent associations of retinopathy lesions, arteriolar narrowing and venular dilation with these metabolic disorders, suggesting a microvascular component in either the pathogenesis or manifestation of these disorders. Further, several of these signs have been associated with future risk of cardiovascular outcomes, such as coronary heart disease and stroke, independently of traditional risk factors. This review will examine in detail the evidence linking retinal vascular signs with metabolic disorders and discuss their implications for research and clinical practice.

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.

A multinational assessment of complications in type 1 diabetes: the DiaMond substudy of complications (DiaComp) level 1

The objectives of this study were to describe the global geographic variation of microvascular and macrovascular complications in childhood onset type 1 diabetes (T1D) and to relate any such variation to diabetes care activities such as self blood glucose monitoring and intensive insulin therapy. The DiaComp study is a multinational (17 countries) cross-sectional study of complications in T1D (n=2,657). All participants were diagnosed at < 15 years of age and had a diabetes duration of 5-24 years when surveyed. Complications were assessed by self-report of physician diagnosis. Twenty-two centres in 17 countries achieved at least a 67% response rate and are included in the analyses. Central European centres exhibited high rates of retinopathy (Lithuania=31.6%, Romania=24.2%), laser treatment (Lithuania=25.4%) and neuropathy (Lithuania=29.9%, Romania=12.4%) in those with short duration of diabetes (5-15 years), as did Cuba for neuropathy (15.4%). For retinopathy the geographic variation in the short-duration group was also pronounced, ranging from 1.6% in Italy to 41.6% in Lithuania, and from 0% in Brazil, Italy and Australia, to 29.9% in Lithuania for laser treatment. Variation was less dramatic for the prevalence of complications in the long-duration group (15-25 years). Hypertension and duration were strong consistent predictors of all complications, while women had higher prevalence for half the complications (retinopathy, laser treatment and renal disease). Intensive insulin therapy and self-monitoring of blood glucose showed little association with prevalence of complications. In conclusion, this first population-based account of the geographic variation of T1D complications has demonstrated substantial variation. However, the healthcare practice variables that were measured contributed little toward explaining this variation.

Retinal vascular manifestations of metabolic disorders

Metabolic diseases have profound effects on the structure and function of the retinal circulation. The recent development of retinal photography and digital imaging has enabled more precise documentation of diabetic retinopathy, as well as other retinal microvascular changes, such as retinal arteriolar narrowing, venular dilation and isolated retinopathy signs in nondiabetic individuals. These retinal microvascular signs have been shown to be associated with long-term risks of type 2 diabetes and hypertension, components of the metabolic syndrome (e.g. obesity, dyslipidemia), and a range of macro- and micro-vascular conditions (e.g. stroke, cardiovascular mortality). There is evidence that endothelial dysfunction and inflammation might be possible mechanisms involved in the development of various retinal microvascular changes in patients with diabetes, hypertension and other metabolic disorders. Further understanding of how these processes influence the retinal vasculature might help to elucidate the diverse vascular manifestations of metabolic diseases.

Early glycemic control, age at onset, and development of microvascular complications in childhood-onset type 1 diabetes: a population-based study in northern Sweden

OBJECTIVE

The aim of this work was to study the impact of glycemic control (HbA(1c)) early in disease and age at onset on the occurrence of incipient diabetic nephropathy (MA) and background retinopathy (RP) in childhood-onset type 1 diabetes.

RESEARCH DESIGN AND METHODS

All children, diagnosed at 0-14 years in a geographically defined area in northern Sweden between 1981 and 1992, were identified using the Swedish Childhood Diabetes Registry. From 1981, a nationwide childhood diabetes care program was implemented recommending intensified insulin treatment. HbA(1c) and urinary albumin excretion were analyzed, and fundus photography was performed regularly. Retrospective data on all 94 patients were retrieved from medical records and laboratory reports.

RESULTS

During the follow-up period, with a mean duration of 12 +/- 4 years (range 5-19), 17 patients (18%) developed MA, 45 patients (48%) developed RP, and 52% had either or both complications. A Cox proportional hazard regression, modeling duration to occurrence of MA or RP, showed that glycemic control (reflected by mean HbA(1c)) during the follow-up was significantly associated with both MA and RP when adjusted for sex, birth weight, age at onset, and tobacco use as potential confounders. Mean HbA(1c) during the first 5 years of diabetes was a near-significant determinant for development of MA (hazard ratio 1.41, P = 0.083) and a significant determinant of RP (1.32, P = 0.036). The age at onset of diabetes significantly influenced the risk of developing RP (1.11, P = 0.021). Thus, in a Kaplan-Meier analysis, onset of diabetes before the age of 5 years, compared with the age-groups 5-11 and >11 years, showed a longer time to occurrence of RP (P = 0.015), but no clear tendency was seen for MA, perhaps due to lower statistical power.

CONCLUSIONS

Despite modern insulin treatment, >50% of patients with childhood-onset type 1 diabetes developed detectable diabetes complications after approximately 12 years of diabetes. Inadequate glycemic control, also during the first 5 years of diabetes, seems to accelerate time to occurrence, whereas a young age at onset of diabetes seems to prolong the time to development of microvascular complications.

Longitudinal study examining the risk factors for proliferative retinopathy and maculopathy in type-I diabetes: The Royal College of Physicians of Edinburgh Diabetes Register Group

PURPOSE

The aim of this study was to determine whether there were any differences in the risk factors for developing proliferative diabetic retinopathy or maculopathy in patients with type-I diabetes.

METHOD

In all, 1632 patients aged 35 years or younger at diagnosis and treated with insulin, attending six hospital diabetes clinics in Scotland and included on the Royal College of Physicians of Edingburgh Diabetes Register were followed up for a median of 4.0 (2.5-5.5 years: interquartile range). All patients were screened at least annually for diabetic retinopathy using direct ophthalmoscopy, and positive findings were confirmed using slit lamp by an ophthalmologist.

RESULTS

Duration of diabetes and HbA1c were the important risk factors for developing proliferative retinopathy, while the duration of diabetes, systolic blood pressure, and HbA1c were the important factors of maculopathy. The adjusted relative incidence for proliferative retinopathy with a HbA1c in the highest quartile was 26.7, while for maculopathy it was only 2.29. Carstairs deprivation score was not associated with either retinal pathology. There was a plateau effect for systolic blood pressure of 140 mmHg and for duration of diabetes of 16 years for developing either maculopathy or proliferative retinopathy.

CONCLUSION

Duration of diabetes is a strong predictor for maculopathy and proliferative disease, but is relatively more important for proliferative disease. Raised systolic blood pressure is relatively more important for predicting maculopathy, while raised HbA1c is relatively more important for developing proliferative retinopathy.

BglII gene polymorphism of the alpha2beta1 integrin gene is a risk factor for diabetic retinopathy in Caucasians with type 2 diabetes

Platelets are thought to be involved in the pathogenesis of diabetic retinopathy. The BglII gene polymorphism of the alpha2beta1 integrin, which is a platelet collagen receptor, has been suggested as a genetic risk factor for diabetic retinopathy in Japanese subjects. The aim of this study was to look for a relationship between the BglII gene polymorphism of the alpha2beta1 integrin gene and the development of diabetic retinopathy in Caucasians with type 2 diabetes. Subjects with type 2 diabetes and diabetic retinopathy (n=163) were compared with diabetic subjects without diabetic retinopathy (n=95). A significantly higher frequency of the BglII (+/+) genotype of the gene polymorphism of the alpha2beta1 integrin gene was found in patients with diabetic retinopathy compared with patients without diabetic retinopathy (19.6% vs 7.4%; P=0.008). The present study demonstrates that the BglII (+/+) genotype of the gene polymorphism of the alpha2beta1 integrin gene is an independent risk factor (odds ratio: 2.4, 95% confidence interval 1.0-6.0; P<0.05) for diabetic retinopathy in Caucasians with type 2 diabetes.

A hemochromatosis-causing mutation C282Y is a risk factor for proliferative diabetic retinopathy in Caucasians with type 2 diabetes

Iron metabolism might be involved in the pathogenesis of type 2 diabetes and in the pathogenesis of diabetic retinopathy. C282Y and H63D mutations in the hemochromatosis (HFE) gene are associated with increased serum iron levels and consequently with hereditary hemochromatosis. In the present study, we searched for a relationship between C282Y and H63D gene mutations and the development of proliferative diabetic retinopathy in Caucasians with type 2 diabetes. For this purpose, 90 subjects with type 2 diabetes with proliferative diabetic retinopathy (PDR) were compared to 133 diabetic subjects without PDR. There was a significantly higher frequency of the C282Y heterozygotes in patients with PDR compared to subjects without it (OR=3.0, 95% CI=1.2-8.0; p=0.02), whereas no association was demonstrated between PDR and H63D genotypes (OR=1.1, 95% CI=0.6-2.2; p=0.7). Logistic regression analysis revealed that the C282Y mutation was a significant independent risk factor for the development of PDR (OR=6.1, 95% CI=1.2-30.5; p=0.027). These data suggest that heterozygosity for C282Y might be a novel risk factor for PDR in Caucasians with type 2 diabetes.

Low content of the natural ocular anti-angiogenic agent pigment epithelium-derived factor (PEDF) in aqueous humor predicts progression of diabetic retinopathy

AIMS/HYPOTHESIS

Retinopathy is the most common microvascular complication of diabetes. Our aim was to address the predictive value of pro-angiogenic and anti-angiogenic markers for progression of retinopathy.

METHODS

Aqueous humor was collected at cataract surgery from 32 diabetic patients who had no or very mild retinopathy (ETDRS stage </=20) and 33 normoglycaemic control subjects. Content of pro-angiogenic vascular endothelial growth factor and angiogenic inhibitor pigment epithelium-derived factor were determined. ANGIOGENIC activity was quantified by measuring its effect on the migration of capillary endothelial cells. The predictive value of the initial level of these markers for progression of retinopathy was studied by following the probands for a maximum of 75 months.

RESULTS

In the aqueous fluid content of vascular endothelial growth factor was increased in diabetic patients (mean values 492 versus 292 pg/ml; p=0.0052), and pigment epithelium-derived factor values were decreased (mean values 1740 versus 3680 ng/ml; p=0.0058) compared to control subjects. Of the diabetic patients ten progressed during follow-up (ETDRS stage >47B). This subgroup showed lower pigment epithelium-derived factor content when compared to non-progressors and control subjects. Migratory activity in samples of patients from the control group and in diabetic patients without progression was generally inhibitory due to pigment epithelium-derived factor. Inhibition was blocked by neutralizing antibodies to pigment epithelium-derived factor. In diabetic patients initial angiogenic activity was higher in those who later developed retinopathy (vs. controls p=0.00005; vs. no progressors p=0.0003). Both pigment epithelium-derived factor and migratory response predicted progression.

CONCLUSION/INTERPRETATION

Pigment epithelium-derived factor is an important negative regulator of angiogenic activity of aqueous humor. Its content in the aqueous humor of diabetic patients strongly predicts who among them will develop progression of retinopathy.

The incidence of retinopathy 10 years after diagnosis in young adult people with diabetes: results from the nationwide population-based Diabetes Incidence Study in Sweden (DISS)

OBJECTIVE

To estimate the prevalence and severity of diabetic retinopathy (DR) 10 years after diagnosis in a nationwide population-based cohort study of young adult diabetic patients in Sweden.

RESEARCH DESIGN AND METHODS

The Diabetes Incidence Study in Sweden (DISS) aims to register all incident cases of diabetes aged 15-34 years in Sweden. In 1987-1988, 806 cases were reported, and 627 (78%) of them were followed up with regard to retinopathy 8-10 years later. The assessment was based on retinal photographs in most cases (86%).

RESULTS

Ten years after diagnosis, retinopathy was found in 247 patients (39%). The retinopathy was mild in 206 (33%), whereas 30 (4.8%) patients had moderate nonproliferative DR (NPDR) and 11 (1.8%) had proliferative DR (PDR). Patients with retinopathy had worse glycemic control during the years than patients without (HbA(1c) 8.1 +/- 1.5% and 6.8 +/- 1.2%, respectively; P < 0.001). In a Cox regression analysis, time to retinopathy was related to high HbA(1c) (P < 0.001) and high BMI (P = 0.001). Patients with type 2 diabetes had an increased prevalence of severe retinopathy (NPDR or PDR) compared with those with type 1 diabetes (14 of 93 [15%] versus no or mild 24 of 471 [5%], respectively; P < 0.001).

CONCLUSIONS

Despite modern diabetes management, 39% of young adult diabetic patients developed retinopathy within the first 10 years of the disease. Nevertheless, compared with the prevalence of retinopathy (63%), after a similar duration of diabetes before the Diabetes Control and Complications Trial, this prevalence was clearly lower. Current treatment aimed to achieve strict glycemic control has reduced the risk for developing retinopathy.

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.

Cigarette smoking: an important renal risk factor - far beyond carcinogenesis

In recent years, it has become apparent that smoking has a negative impact on renal function, being one of the most important remediable renal risk factors. It has been clearly shown that the risk for high-normal urinary albumin excretion and microalbuminuria is increased in smoking compared to non-smoking subjects of the general population. Data from the Multiple Risk Factor Intervention Trial (MRFIT) indicate that at least in males, smoking increases the risk to reach end-stage renal failure. Smoking is particularly "nephrotoxic" in older subjects, subjects with essential hypertension and patients with preexisting renal disease. Of interest, the magnitude of the adverse renal effect of smoking seems to be independent of the underlying renal disease. Death-censored renal graft survival is decreased in smokers, indicating that smoking also damages the renal transplant. Cessation of smoking has been show to reduce the rate of progression of renal failure both in patients with renal disease or a renal transplant. The mechanisms of smoking-induced renal damage are only partly understood and comprise acute hemodynamic (e.g., increase in blood pressure and presumably intraglomerular pressure) and chronic effects (e.g., endothelial cell dysfunction). Renal failure per se leads to an increased cardiovascular risk. The latter is further aggravated by smoking. Particularly survival of smokers with diabetes mellitus on hemodialysis is abysmal. In the present review article the current state of knowledge about the renal risks of smoking is reviewed. It is the aim of the article to point out that smoking not only increases the risk of renal cell carcinoma or uroepithelial cell carcinoma, but also the risk of a faster decline of renal function. The latter is a relatively new negative aspect which has not been widely recognized.