Diabetic retinopathy is associated with mortality and cardiovascular disease incidence: the EURODIAB prospective complications study

Large-fiber dysfunction in diabetic peripheral neuropathy is predicted by cardiovascular risk factors

OBJECTIVE

Diabetic large-nerve fiber dysfunction, as measured by vibration perception threshold (VPT), predicts foot ulceration, amputation, and mortality. Thus, determination of modifiable risk factors is of great clinical importance.

RESEARCH DESIGN AND METHODS

We assessed 1,407 patients with type 1 diabetes and a normal VPT participating in the EURODIAB Prospective Complications Study, at baseline mean +/- SD age of 32.7 +/- 10.2 years with diabetes duration of 14.7 +/- 9.3 years and follow-up of 7.3 +/- 0.6 years. VPT was measured using biothesiometry on the right big toe and medial malleolus. An abnormal result was defined as >2 SD from the predicted mean for the patient s age.

RESULTS

An abnormal VPT was associated with an increased incidence of gangrene, amputation, foot ulceration, leg bypass or angioplasty, and mortality (P < OR = 0.02). The incidence of abnormal VPT was 24% over the 7.3-year follow-up. Duration of diabetes and A1C significantly influenced the incidence of abnormal VPT (P < 0.0001). After correction for these, established risk factors for cardiovascular disease (CVD), including male sex (P = 0.0004), hypertension (P < 0.0001), total cholesterol (P = 0.002), LDL cholesterol (P = 0.01), smoking (P < 0.0001), weight (P < 0.0001), and diabetes complications (retinopathy [P = 0.0001], nephropathy [P = 0.01], and autonomic neuropathy [P = 0.001]), were all found to be significant risk factors. A previous history of CVD doubled the incidence of abnormal VPT.

CONCLUSIONS

This prospective study indicates that cardiovascular risk factors predict development of large-fiber dysfunction, which may account for the high mortality rate in patients with an abnormal VPT, and emphasizes the importance of early determination of VPT to detect subclinical neuropathy and to address cardiovascular risk factors.

Good glycemic control remains crucial in prevention of late diabetic complications--the Linköping Diabetes Complications Study

BACKGROUND

Several intervention studies have convincingly demonstrated the importance of good glycemic control to avoid long-term diabetic complications, but the importance of other risk factors remains controversial. We previously reported a markedly reduced incidence of severe retinopathy and nephropathy during the past decades in an unselected population of type 1 diabetes mellitus diagnosed in childhood. The aim of the present study was to analyze possible risk factors, which could explain the improved prognosis.

METHODS

In this longitudinal population-based cohort study, we followed all 269 patients in whom type 1 diabetes mellitus was diagnosed in childhood 1961-1985 in a well-defined geographical area in Sweden. The patients were followed until the end of 1990 s. Multivariable regression models were used to analyze the importance of hemoglobin A1c (HbA(1c)), diabetes duration, blood pressure, cardiovascular risk factors and persisting C-peptide secretion for the development of diabetic retinopathy and nephropathy.

RESULTS

Beside longer duration and higher HbA(1c), blood pressure and lipid values were higher and cardiovascular disease and smoking were more common in patients with severe complications. However, multivariable analysis abolished these associations. Diabetes duration and long-term HbA(1c) were the only significant independent risk factors for both retinopathy and nephropathy. The risk of overt nephropathy increased substantially when HbA(1c) was above 9.6% [Diabetes Control and Complications Trial (DCCT) corrected value], while the risk of severe retinopathy increased already when HbA(1c) exceeded 8.6%.

CONCLUSION

In this unselected population, glycemic control was the only significant risk factor for the development of long-term complications.

Diabetic retinopathy is associated with insulin resistance and cardiovascular autonomic dysfunction in type 2 diabetic patients

Diabetic retinopathy (DR) and cardiovascular autonomic dysfunction are associated with high mortality in type 2 diabetic patients. This preliminary study was therefore designed to test the hypothesis that DR is associated with insulin resistance and cardiovascular autonomic dysfunction in type 2 diabetic patients without insulin treatment. Seventy persons were diagnosed to have type 2 diabetes in the examination from June 2004 to May 2006. The study group consisted of 29 type 2 diabetic patients with DR (age: 58+/-6 years, mean+/-s.d.) and 41 type 2 diabetic patients with no DR (NDR) (n=41, 58+/-5 years). Cardiovascular autonomic function was assessed by baroreflex sensitivity (BRS), heart rate variability, plasma norepinephrine concentration and cardiac (123)I-metaiodobenzylguanidine (MIBG) scintigraphic findings. DR patients had lower BRS, early and delayed (123)I-MIBG myocardial uptake values and higher percent washout rate (WR) of (123)I-MIBG than the NDR patients. With respect to metabolic findings, DR patients had higher fasting plasma insulin concentration (P<0.0001) and higher homeostasis model assessment (HOMA) index (P<0.00001) than the NDR patients. Multiple logistic regression analysis revealed that the presence of DR was independently predicted by HOMA index and the percent WR of (123)I-MIBG (P<0.01 and P<0.05, respectively). Our results suggest that DR is associated with depressed cardiovascular autonomic function and insulin resistance and that HOMA index and the percent WR of (123)I-MIBG are independently associated with DR in Japanese patients with type 2 diabetes mellitus.

End-organ dysfunction and cardiovascular outcomes: the role of the microcirculation

Risk factors for cardiovascular disease mediate their effects by altering the structure and function of wall and endothelial components of arterial blood vessels. A pathological change in the microcirculation plays a pivotal role in promoting end-organ dysfunction that not only predisposes to further organ damage, but also increases the risk for future macrovascular events. The microcirculation is recognized as the site where the earliest manifestations of cardiovascular disease, especially inflammatory responses, occur that may play a pivotal role in driving the atherosclerotic process in conduit vessels. Furthermore, the vast surface area of the endothelium compared with conduit vessels means that the vascular effects of endothelial dysfunction or activation will be most apparent in this section of the vasculature. Current techniques providing indices of vascular health focus on large arteries without providing insight into the structure and function of small vessels. Techniques capable of detecting microvascular damage and monitoring the response to therapeutic interventions, especially in vulnerable target organs of interest, may improve risk stratification and represent a valuable surrogate for future cardiovascular outcome.

Factors of cardiovascular risk in patients with type 2 diabetes and incipient nephropathy

BACKGROUND

Microalbuminuria was originally established as a predictor of renal failure and an independent risk factor for cardiovascular disease in patients with diabetes mellitus as well as in general population. The aim of our study is to assess the relationship between microalbuminuria and the other risk factors in diabetics and their prevalence.

METHODS

Sixty five patients, 22 men and 43 women with mean age 58.6+/-10.09, with type 2 diabetes, were hospitalized in the Department of Internal Medicine in the University Hospital Center "Mother Teresa" in Tirana, Albania, between March 2007 and February 2008. These patients with a mean duration of diabetes 6.09+/-5.41 were divided in two groups: with (Group A: 24 patients) and without (Group B: 41 patients) microalbuminuria and each group was evaluated for left ventricular mass index (LVMI), body mass index (BMI), glycosylated hemoglobin (HbA1C), lipid profile and intima media thickness (IMT).

RESULTS

The prevalence of microalbuminuria in our study was 32.3%. The prevalence of microalbuminuria in males was 37.5 and in females 62.5%. The microalbuminuric patients were older ( 59.71+/-9.87 vs 57.07+/-10.32) and had a longer duration of diabetes (7.74+/-5.74 vs 4.45+/-5.08) compared with normoalbuminuric patients (p=0.01). The Group A had significantly higher LVMI compared with Group B ( p=0.02). The prevalence of obesity (BMI>30 kg/m2) in our sample was 44.6%. In Group A the mean BMI (30.13+/-4.98) was significantly higher compared with Group B (28.00+/-3.72, p=0.04). Diabetic retinopathy was more frequent in Group A compared with Group B ( 33.3% vs 14.6%, p=0.05). The mean value of IMT was higher in Group A compared with Group B (1.28+/-0.35 vs 1.09+/-0.28, p=0.03).

CONCLUSION

In patients with type 2 diabetes and microalbuminuria LVMI, IMT, BMI, duration of diabetes was significantly higher compared with patients with type 2 diabetes and normoalbuminuria.

Prevalence of diabetic retinopathy in India: Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study report 2

OBJECTIVE

The aim of the study was to estimate the prevalence of diabetic retinopathy in an urban Indian population older than 40 years.

DESIGN

A population-based cross-sectional study.

PARTICIPANTS

Five thousand nine hundred ninety-nine subjects residing in Chennai, India, were enumerated.

METHODS

A multistage random sampling, based on socioeconomic criteria, was followed. Identified subjects with diabetes mellitus (based on the World Health Organization criteria) underwent detailed examination at the base hospital. The fundi of all patients were photographed using 45 degrees , 4-field stereoscopic digital photography. The diagnosis of diabetic retinopathy was based on Klein's classification of the Early Treatment Diabetic Retinopathy Study scale.

MAIN OUTCOME MEASURES

These included age- and gender-adjusted prevalence of diabetes and diabetic retinopathy, and correlation of prevalence with history-based risk factors.

RESULTS

The age- and gender-adjusted prevalence rate of diabetes in an urban Chennai population was 28.2% (95% confidence interval [CI], 27.0-29.3), and the prevalence of diabetic retinopathy in general population was 3.5% (95% CI, 3.49-3.54). The prevalence of diabetic retinopathy in the population with diabetes mellitus was 18.0% (95% CI, 16.0-20.1). History-based variables that were significantly associated with increased risk of diabetic retinopathy included gender (men at greater risk; odds ratio [OR], 1.41; 95% CI, 1.04-1.91); use of insulin (OR, 3.52; 95% CI, 2.05-6.02); longer duration of diabetes (>15 years; OR, 6.43; 95% CI, 3.18-12.90); and subjects with known diabetes mellitus (OR, 2.98; 95% CI, 1.72-5.17). Differences in the socioeconomic status did not influence the occurrence of diabetic retinopathy.

CONCLUSIONS

The prevalence of diabetic retinopathy was 18% in an urban population with diabetes mellitus in India. The duration of diabetes is the strongest predictor for diabetic retinopathy.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Retinopathy in type 2 diabetes mellitus is associated with increased intima-media thickness and endothelial dysfunction

BACKGROUND

Microangioathy and macroangiopathy in type 2 diabetes mellitus (T2DM) frequently coexist. Both types of vascular complications share traditional risk factors. It is not clear whether the presence of microangiopathy, such as diabetic retinopathy (DR), constitutes a predictor of atherosclerosis in T2DM. Here we described the search for the association between DR and intima-media thickness (IMT) in T2DM. We also compared endothelial function in subjects with and without DR.

MATERIAL AND METHODS

We examined 182 consecutive patients with T2DM for at least 5 years (mean age at examination 56.3 +/- 6.52 years). We assessed (i) IMT of carotid artery by ultrasound and (ii) endothelial function by flow-mediated dilatation (FMD) method as well as by measurement of concentrations of von Willebrand factor (vWF) and s-ICAM-1. All patients underwent ophthalmological examination. Statistical analysis included Student's, Mann-Whitney, chi-square, Fisher tests and multiple regression.

RESULTS

DR was found in 71 (39.0%) subjects. IMT was higher in patients with DR than those without DR (0.87 mm vs. 0.79 mm, respectively, P = 0.0001). FMD was lower in the complication group than in subjects without DR (8.38% vs. 10.45%, respectively, P = 0.0023). Concentrations of s-ICAM-1 and vWF were not different between the groups. In multiple regression analysis, DR was among the predictors of increased IMT (P = 0.016) and decreased FMD (P = 0.002). We did not find a significant association of DR with vWF and s-ICAM-1 (P = 0.09 and P = 0.11, respectively).

CONCLUSIONS

DR is associated with increased IMT and endothelial dysfunction in T2DM. Impaired endothelial function may be a common denominator of pathogenesis of microvascular complications and atherosclerosis in T2DM.

Effect of candesartan on prevention (DIRECT-Prevent 1) and progression (DIRECT-Protect 1) of retinopathy in type 1 diabetes: randomised, placebo-controlled trials

BACKGROUND

Results of previous studies suggest that renin-angiotensin system blockers might reduce the burden of diabetic retinopathy. We therefore designed the DIabetic REtinopathy Candesartan Trials (DIRECT) Programme to assess whether candesartan could reduce the incidence and progression of retinopathy in type 1 diabetes.

METHODS

Two randomised, double-blind, parallel-design, placebo-controlled trials were done in 309 centres worldwide. Participants with normotensive, normoalbuminuric type 1 diabetes without retinopathy were recruited to the DIRECT-Prevent 1 trial and those with existing retinopathy were recruited to DIRECT-Protect 1, and were assigned to candesartan 16 mg once a day or matching placebo. After 1 month, the dose was doubled to 32 mg. Investigators and participants were unaware of the treatment allocation status. The primary endpoints were incidence and progression of retinopathy and were defined as at least a two-step and at least a three-step increase on the Early Treatment Diabetic Retinopathy Study (ETDRS) scale, respectively. These trials are registered with ClinicalTrials.gov, numbers NCT00252733 for DIRECT-Prevent 1 and NCT00252720 for DIRECT-Protect 1.

FINDINGS

1421 participants (aged 18-50 years) were randomly assigned to candesartan (n=711) or to placebo (n=710) in DIRECT-Prevent 1, and 1905 (aged 18-55 years) to candesartan (n=951) or to placebo (n=954) in DIRECT-Protect 1. Incidence of retinopathy was seen in 178 (25%) participants in the candesartan group versus 217 (31%) in the placebo group. Progression of retinopathy occurred in 127 (13%) participants in the candesartan group versus 124 (13%) in the placebo group. Hazard ratio (HR for candesartan vs placebo) was 0.82 (95% CI 0.67-1.00, p=0.0508) for incidence of retinopathy and 1.02 (0.80-1.31, p=0.85) for progression of retinopathy. The post-hoc outcome of at least a three-step increase for incidence yielded an HR of 0.65 (0.48-0.87, p=0.0034), which was attenuated but still significant after adjustment for baseline characteristics (0.71, 0.53-0.95, p=0.046). Final ETDRS level was more likely to have improved with candesartan treatment in both DIRECT-Prevent 1 (odds 1.16, 95% CI 1.05-1.30, p=0.0048) and DIRECT-Protect 1 (1.12, 95% CI 1.01-1.25, p=0.0264). Adverse events did not differ between the treatment groups.

INTERPRETATION

Although candesartan reduces the incidence of retinopathy, we did not see a beneficial effect on retinopathy progression.

Relationship between risk factors and mortality in type 1 diabetic patients in Europe: the EURODIAB Prospective Complications Study (PCS)

OBJECTIVE

The purpose of this study was to examine risk factors for mortality in patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Baseline risk factors were measured in the EURODIAB Prospective Cohort Study with 2,787 type 1 diabetic patients (51% men and 49% women) recruited from 16 European countries. Mortality data were collected during a 7-year follow-up.

RESULTS

There was an annual mortality rate of 5 per 1,000 person-years in patients with type 1 diabetes (mean age at baseline 33 years, range 15-61 years); of the total 2,787 subjects, 102 died. The final multivariable model contained age at baseline (standardized hazard ratio 1.78 [95% CI 1.44-2.20]), A1C (1.18 [0.95-1.46]), waist-to-hip ratio (WHR) (1.32 [1.14-1.52]), pulse pressure (1.33 [1.13-1.58]), and non-HDL cholesterol (1.33 [1.12-1.60]) as risk factors for all-cause mortality. Macroalbuminuria (2.39 [1.19-4.78]) and peripheral (1.88 [1.06-3.35]) and autonomic neuropathy (2.40 [1.32-4.36]) were the most important risk markers for mortality. Similar risk factors were found for all-cause, non-cardiovascular disease (CVD), unknown-cause, and CVD mortality.

CONCLUSIONS

Important risk factors for the increased total and non-CVD mortality in type 1 diabetic patients are age, WHR, pulse pressure, and non-HDL cholesterol. Microvascular complications from macroalbuminuria and peripheral and autonomic neuropathy are strong risk markers for future mortality exceeding the effect of the traditional risk factors.

Proliferative diabetic retinopathy in type 2 diabetes is related to coronary artery calcium in the Veterans Affairs Diabetes Trial (VADT)

OBJECTIVE

Increasing evidence suggests that macrovascular disease and retinopathy may be more closely linked than previously believed. We determined the relationship between retinopathy and coronary atherosclerosis as measured by computed tomography-detectable coronary artery calcium (CAC).

RESEARCH DESIGN AND METHODS

The cross-sectional association between CAC and retinopathy was assessed on a Veteran Affairs Diabetes Trial subsample of 204 subjects with a mean duration of type 2 diabetes of 12.3 +/- 8.3 years.

RESULTS

Retinopathy was correlated with CAC (r = 0.19, P = 0.006). Median CAC increased across retinopathy categories: 197 in those with no retinopathy, 229 in those with microaneurysms only, 364 in those with mild nonproliferative diabetic retinopathy (NPDR), 300 in those with moderate to severe NPDR, and 981 in those with proliferative diabetic retinopathy (PDR). Stepwise multivariable linear regression analysis was performed to find a parsimonious subset of relevant risk factors to include along with PDR in predicting CAC. After adjustment for either this subset of standard factors (P = 0.047) or a more extensive panel of risk factors (P = 0.035), PDR was significantly associated with CAC. Moreover, using logistic regression, individuals with PDR were approximately sixfold more likely to have CAC >400 than those with no PDR, even after adjustment for other CVD risk factors.

CONCLUSIONS

These data indicate an important relationship between retinopathy and extent of CAC and suggest the potential to identify and treat shared risk factors for these common micro- and macrovascular complications.

Proliferative retinopathy and proteinuria predict mortality rate in type 1 diabetic patients from Fyn County, Denmark

AIMS/HYPOTHESIS

We evaluated the effect of diabetic retinopathy on 25 year survival rate among a population-based cohort of type 1 diabetic patients from Fyn County, Denmark.

METHODS

In 1973 all diabetic patients from Fyn County, Denmark with onset before the age of 30 years as of 1 July 1973 were identified (n=727). In 1981, only 627 patients were still alive and resident in Denmark. Of these, 573 (91%) participated in a clinical baseline examination, in which diabetic retinopathy was graded and other markers of diabetes measured. Mortality rate was examined in a 25 year follow-up and related to the baseline examination.

RESULTS

Of the 573 patients examined at baseline in 1981 and 1982, 297 (51.8%) were still alive in November 2006. Of the others, 256 (44.7%) had died, three (0.5%) had left Denmark and 17 (3%) were of unknown status. Age- and sex-adjusted HRs of mortality rate were 1.01 (95% CI 0.72-1.42) and 2.04 (1.43-2.91) for patients with non-proliferative and proliferative retinopathy respectively at baseline compared with patients with no retinopathy. After adjusting for proteinuria, HR among patients with proliferative retinopathy lost statistical significance, but still remained 1.48 (95% CI 0.98-2.23). The 10 year survival rate of patients who had proliferative retinopathy as well as proteinuria at baseline was 22.2% and significantly lower (p<0.001) than in patients with proteinuria only (70.3%), proliferative retinopathy only (79.0%) or neither (86.6%).

CONCLUSIONS/INTERPRETATION

Proliferative retinopathy and proteinuria predict mortality rate in a population-based cohort of type 1 diabetic patients. In combination they act even more strongly. Non-proliferative diabetic retinopathy did not affect survival rate.

Self-reported age-related eye diseases and visual impairment in the United States: results of the 2002 national health interview survey

OBJECTIVES

We sought to establish national data on the prevalence of visual impairment, blindness, and selected eye conditions (cataract, diabetic retinopathy, glaucoma, and macular degeneration) and to characterize these conditions within sociodemographic subgroups.

METHODS

Information on self-reported visual impairment and diagnosed eye diseases was collected from 31,044 adults. We calculated weighted prevalence estimates and odds ratios with logistic regression using SUDAAN.

RESULTS

Among noninstitutionalized US adults 18 years and older, the estimated prevalence for visual impairment was 9.3% (19.1 million Americans), including 0.3% (0.7 million) with blindness. Lifetime prevalence of diagnosed diseases was as follows: cataract, 8.6% (17 million); glaucoma, 2.0% (4 million); macular degeneration, 1.1% (2 million); and diabetic retinopathy, 0.7% (1.3 million). The prevalence of diabetic retinopathy among persons with diagnosed diabetes was 9.9%.

CONCLUSIONS

We present the most recently available national data on self-reported visual impairment and selected eye diseases in the United States. The results of this study provide a baseline for future public health initiatives relating to visual impairment.

Diabetic retinopathy is associated with an increased incidence of cardiovascular events in Type 2 diabetic patients

AIMS

We investigated the association of diabetic retinopathy with the risk of incident cardiovascular disease (CVD) events in a large cohort of Type 2 diabetic adults.

METHODS

Our study cohort comprised 2103 Type 2 diabetic outpatients who were free of diagnosed CVD at baseline. Retinal findings were classified based on fundoscopy (by a single ophthalmologist) to categories of no retinopathy, non-proliferative retinopathy and proliferative/laser-treated retinopathy. Outcomes measures were incident CVD events (i.e. non-fatal myocardial infarction, non-fatal ischaemic stroke, coronary revascularization procedures or cardiovascular death).

RESULTS

During approximately 7 years of follow-up, 406 participants subsequently developed incident CVD events, whereas 1697 participants remained free of diagnosed CVD. After adjustment for age, body mass index, waist circumference, smoking, lipids, glycated haemoglobin, diabetes duration and medications use, patients with non-proliferative or proliferative/laser-treated retinopathy had a greater risk (P < 0.001 for all) of incident CVD events than those without retinopathy [hazard ratio 1.61 (95% confidence interval 1.2-2.6) and 3.75 (2.0-7.4) for men, and 1.67 (1.3-2.8) and 3.81 (2.2-7.3) for women, respectively]. After additional adjustment for hypertension and advanced nephropathy (defined as overt proteinuria and/or estimated glomerular filtration rate < or = 60 ml/min/1.73 m(2)), the risk of incident CVD remained markedly increased in those with proliferative/laser-treated retinopathy [hazard ratio 2.08 (1.02-3.7) for men and 2.41 (1.05-3.9) for women], but not in those with non-proliferative retinopathy.

CONCLUSIONS

Diabetic retinopathy (especially in its more advanced stages) is associated with an increased CVD incidence independent of other known cardiovascular risk factors.

Are comorbidity indices useful in predicting all-cause mortality in Type 2 diabetic patients? Comparison between Charlson index and disease count

BACKGROUND AND AIMS

Several studies have shown that comorbidity is important in predicting morbidity and mortality in the general population. However, few studies have assessed the validity of comorbidity indices in diabetic patients. The aim of the present study was to compare the predictive value of disease count and Charlson's Comorbidity Index (CCI) for 3-year mortality in type 2 diabetic (T2D) patients.

METHODS

The study was performed on a consecutive series of 1667 T2D outpatients. Comorbidity was assessed using Charlson's index, whereas the diseases used to calculate Charlson's score were taken into account for disease count. Information on all-cause mortality over the 3-year follow-up period was obtained from the City of Florence Registry Office.

RESULTS

Mean duration of follow-up (+/-SD) was 31.4+/-10.6 months. One hundred and ninety-nine (11.9%) patients died during follow-up, with a yearly mortality rate of 4.7%. At multivariate analysis, after adjustment for sex and age, each additional disease was associated with a 54 [37-77]% increase in all-cause mortality. Mortality increased by 31 [21-41]% for each incremental point of Charlson's comorbidity score.

CONCLUSIONS

A simple disease count is as predictive of mortality in T2D patients as the more complex Charlson's index. The possible usefulness of specific comorbidity indices in predicting incident disability in diabetic subjects needs to be further investigated.

Diabetic retinopathy and the risk of coronary heart disease: the Atherosclerosis Risk in Communities Study

OBJECTIVE

We sought to examine the relation of diabetic retinopathy to incident coronary heart disease (CHD).

RESEARCH DESIGN AND METHODS

A population-based, prospective cohort study consisting of 1,524 middle-aged individuals with type 2 diabetes without prevalent CHD and stroke at baseline was conducted. Diabetic retinopathy signs were graded from retinal photographs according to the Early Treatment for Diabetic Retinopathy Study severity scale. Incident CHD events (myocardial infarction, fatal CHD, or coronary revascularization) were identified and validated following standardized protocols.

RESULTS

In our study, 214 (14.7%) participants had diabetic retinopathy. Over an average follow-up of 7.8 years, there were 209 (13.7%) incident CHD events. After controlling for age, sex, race, study center, fasting glucose, A1C, duration of diabetes, blood pressure, antihypertensive treatment, cigarette smoking, BMI, and lipid profile, the presence of diabetic retinopathy was associated with a twofold higher risk of incident CHD events (hazard rate ratio [HR] 2.07 [95% CI 1.38-3.11]) and a threefold higher risk of fatal CHD (3.35 [1.40-8.01]). Further adjustments for inflammatory markers, carotid artery intima-media thickness, or nephropathy had minimal impact on the association. The increased risk of CHD was significant in both men (1.89 [1.08-3.31]) and women (2.16 [1.16-4.02]) with diabetic retinopathy.

CONCLUSIONS

In individuals with type 2 diabetes, the presence of retinopathy signifies an increased CHD risk, independent of known risk factors. Our data support the role of microvascular disease in the pathogenesis of CHD in diabetes.

Interactive effect of retinopathy and macroalbuminuria on all-cause mortality, cardiovascular and renal end points in Chinese patients with Type 2 diabetes mellitus

AIMS

To examine the effect of albuminuria and retinopathy on the risk of cardiovascular and renal events, and all-cause mortality in patients with Type 2 diabetes.

METHODS

A post-hoc analysis of 4416 Chinese patients without macrovascular complications at baseline (age 57.6 +/- 13.3 years). Glomerular filtration rate (eGFR) was estimated by the abbreviated Modification of Diet in Renal Disease Study Group Formula, further adjusted for Chinese ethnicity. Clinical end points were all-cause mortality, cardiovascular events (heart failure or angina, myocardial infarction, lower limb amputation, re-vascularization procedures and stroke) and renal end points (reduction in eGFR by more than 50% or eGFR < 15 ml/min/1.73 m2 or death as a result of renal causes or need for dialysis).

RESULTS

Compared with individuals without complications, subjects with retinopathy and macroalbuminuria had higher rates of cardiovascular events (14.1 vs. 2.4%), renal events (40.0 vs. 0.8%) and death (9.3 vs. 1.7%, P < 0.001). For composite event of death, cardiovascular and renal events, the presence of retinopathy, microalbuminuria alone, macroalbuminuria alone, retinopathy with microalbuminuria or retinopathy with macroalbuminuria increased the risk [hazard ratio (95% CI)] by 1.61 (1.05 to 2.47; P = 0.04), 1.93 (1.38 to 2.69; P < 0.001), 4.34 (3.02 to 6.22; P < 0.001), 2.59 [1.76 to 3.81; P < 0.001) and 6.83 (4.89 to 9.55; P < 0.001) fold, respectively. The relative excess risk as a result of interaction between retinopathy and macroalbuminuria was 15.31, implying biological interaction in the development of renal events.

CONCLUSIONS

In Chinese patients with Type 2 diabetes, retinopathy interacts with macroalbuminuria to increase the risk of composite cardio-renal events.

Diagnosed diabetic retinopathy in France, Italy, Spain, and the United Kingdom

AIM

The objective of this study was to describe the proportion and characteristics of patients diagnosed with diabetic retinopathy (DR) in France, Italy, Spain, and the United Kingdom (UK).

METHODS

To estimate the proportion of patients with type 1 and type 2 diabetes diagnosed with DR, we conducted a cross-sectional survey of general practitioners in each country using physician records. In addition, diabetes specialists were recruited in Italy and Spain. We extracted data from the medical notes of a sample of DR patients to characterize DR severity and clinical characteristics.

RESULTS

The average number of physicians per country was 41 (range: 34-49). The proportion of diagnosed DR ranged from 10.3% (95% CI, 6.7-14.0%) in Spain to 19.6% (95% CI, 16.0-23.1%) in the UK. Of 752 DR patients studied, 53.9% were male; mean age (+/-SD) was 64.2+/-12.8 years. Consistently across countries, mild non-proliferative DR was the most common severity level of diagnosed DR. Proliferative DR (PDR) ranged from 19.7% (France) to 31.5% (UK). Diabetic macular oedema was reported in approximately 10% of patients. Hypertension (73.1%), dyslipidemia (63.2%), and neuropathy (52.1%) were the most common co-morbidities.

CONCLUSIONS

Country-specific prevalence of diagnosed DR may reflect clinical management of diabetes, healthcare systems, or record-keeping accuracy. Across countries, up to 30% of DR patients had a diagnosis of PDR, which could suggest that patients are diagnosed only when their disease is advanced.

Retinopathy predicts cardiovascular mortality in type 2 diabetic men and women

OBJECTIVE

To investigate the association of retinopathy with the risk of all-cause, cardiovascular disease (CVD), and coronary heart disease (CHD) mortality in type 2 diabetic subjects in a population-based 18-year follow-up study with particular emphasis on sex differences.

RESEARCH DESIGN AND METHODS

Our study cohort comprised 425 Finnish type 2 diabetic men and 399 type 2 diabetic women who were free of CVD at baseline. The findings were classified based on standardized clinical ophthalmoscopy to categories of no retinopathy, background retinopathy, and proliferative retinopathy. The study end points were all-cause, CVD, and CHD mortality.

RESULTS

Adjusted Cox model hazard ratios (95% CIs) of all-cause, CVD, and CHD mortality in men were 1.34 (0.98-1.83), 1.30 (0.86-1.96), and 1.18 (0.74-1.89), respectively, for background retinopathy and 3.05 (1.70-5.45), 3.32 (1.61-6.78), and 2.54 (1.07-6.04), respectively, for proliferative retinopathy and in women 1.61 (1.17-2.22), 1.71 (1.17-2.51), and 1.79 (1.13-2.85), respectively, for background retinopathy and 2.92 (1.41-6.06), 3.17 (1.38-7.30), and 4.98 (2.06-12.06), respectively, for proliferative retinopathy.

CONCLUSIONS

Proliferative retinopathy in both sexes and background retinopathy in women predicted all-cause, CVD, and CHD death. These associations were independent of current smoking, hypertension, total cholesterol, HDL cholesterol, glycemic control of diabetes, duration of diabetes, and proteinuria. This suggests the presence of common background pathways for diabetic microvascular and macrovascular disease other than those included in the conventional risk assessment of CVD. The sex difference observed in the association of background retinopathy with macrovascular disease warrants closer examination.

Measuring endothelial function

Dysfunction of the endothelium and of the arterial wall is well described in patients with atherosclerosis, diabetes, and other risk factors for vascular disease. In recent years, clinical research has focused on elucidating the role of this dysfunction in influencing vascular disease progression. Alteration in the structure of arteries and disruption of the homeostatic functions of the endothelium act as a substrate for end-organ damage and the occurrence of vascular events. Dysfunction of the vascular endothelial cells is probably the earliest event promoting atherosclerotic lesion formation. Therefore, methods capable of assessing endothelial function at a preclinical stage hold potential to refine cardiovascular risk stratification and serve as a guide to monitor the effects of therapeutic interventions. A number of methodologies are currently employed to assess endothelial function, but the optimal approach is not firmly established. In this article, we critically appraise the use of different methodologies employed to study endothelial function as a surrogate marker of future cardiovascular risk.

Are retinal microvascular abnormalities associated with large artery endothelial dysfunction and intima-media thickness? The Hoorn Study

It has been hypothesized that microvascular dysfunction affects endothelial dysfunction of the large arteries, which may explain the relationship of microvascular disease with macrovascular disease. The aim of the present study was to investigate the relationship of retinal microvascular disorders with endothelium-dependent FMD (flow-mediated vasodilatation) and carotid IMT (intima-media thickness). A total of 256 participants, aged 60–85 years, 70 with normal glucose metabolism, 69 with impaired glucose metabolism and 109 with Type II diabetes, were included in this study. All participants were ophthalmologically examined, including funduscopy and two field 45° fundus photography, and were graded for retinal sclerotic vessel abnormalities and retinopathy. Retinal arteriolar and venular diameters were measured with a computer-assisted method. Brachial artery, endothelium-dependent FMD and carotid IMT were assessed ultrasonically as measurements of endothelial function and early atherosclerosis respectively. After adjustment for age, sex and glucose tolerance status, retinal vessel diameters, retinal sclerotic vessel abnormalities and retinopathy were not significantly associated with FMD. In contrast with other retinal microvascular abnormalities, retinal venular dilatation was associated with increased IMT [standardized β value (95% confidence interval), 0.14 (0.005–0.25)]. This association was attenuated and lost statistical significance after adjustment for cardiovascular risk factors, in particular after correction for fasting insulin. In the present study, retinal microvascular disorders are not independently associated with impaired FMD. In addition, retinal venular dilatation is associated with increased IMT, although non-significantly after multivariable adjustment for cardiovascular risk factors. Therefore our data provide evidence that retinal microvascular disease is of limited value in risk stratification for future cardiovascular events.