Prevalence of retinopathy differs with age at onset of diabetes in a population of patients with Type 1 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.

Anti-vascular endothelial growth factor for proliferative diabetic retinopathy

BACKGROUND

Proliferative diabetic retinopathy (PDR) is an advanced complication of diabetic retinopathy that can cause blindness. It consists of the presence of new vessels in the retina and vitreous haemorrhage. Although panretinal photocoagulation (PRP) is the treatment of choice for PDR, it has secondary effects that can affect vision. Anti-vascular endothelial growth factor (anti-VEGF), which produces an inhibition of vascular proliferation, could improve the vision of people with PDR.

OBJECTIVES

To assess the effectiveness and safety of anti-VEGFs for PDR and summarise any relevant economic evaluations of their use.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register; 2022, Issue 6); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov, and the WHO ICTRP. We did not use any date or language restrictions. We last searched the electronic databases on 1 June 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing anti-VEGFs to another active treatment, sham treatment, or no treatment for people with PDR. We also included studies that assessed the combination of anti-VEGFs with other treatments. We excluded studies that used anti-VEGFs in people undergoing vitrectomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data, and assessed the risk of bias (RoB) for all included trials. We calculated the risk ratio (RR) or the mean difference (MD), and 95% confidence intervals (CI). We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 15 new studies in this update, bringing the total to 23 RCTs with 1755 participants (2334 eyes). Forty-five per cent of participants were women and 55% were men, with a mean age of 56 years (range 48 to 77 years). The mean glycosylated haemoglobin (Hb1Ac) was 8.45% for the PRP group and 8.25% for people receiving anti-VEGFs alone or in combination. Twelve studies included people with PDR, and participants in 11 studies had high-risk PDR (HRPDR). Twelve studies were of bevacizumab, seven of ranibizumab, one of conbercept, two of pegaptanib, and one of aflibercept. The mean number of participants per RCT was 76 (ranging from 15 to 305). Most studies had an unclear or high RoB, mainly in the blinding of interventions and outcome assessors. A few studies had selective reporting and attrition bias. No study reported loss or gain of 3 or more lines of visual acuity (VA) at 12 months. Anti-VEGFs ± PRP probably increase VA compared with PRP alone (mean difference (MD) -0.08 logMAR, 95% CI -0.12 to -0.04; I2 = 28%; 10 RCTS, 1172 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP may increase regression of new vessels (MD -4.14 mm2, 95% CI -6.84 to -1.43; I2 = 75%; 4 RCTS, 189 eyes; low-certainty evidence) and probably increase a complete regression of new vessels (RR 1.63, 95% CI 1.19 to 2.24; I2 = 46%; 5 RCTS, 405 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP probably reduce vitreous haemorrhage (RR 0.72, 95% CI 0.57 to 0.90; I2 = 0%; 6 RCTS, 1008 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP may reduce the need for vitrectomy compared with eyes that received PRP alone (RR 0.67, 95% CI 0.49 to 0.93; I2 = 43%; 8 RCTs, 1248 eyes; low-certainty evidence). Anti-VEGFs ± PRP may result in little to no difference in the quality of life compared with PRP alone (MD 0.62, 95% CI -3.99 to 5.23; I2 = 0%; 2 RCTs, 382 participants; low-certainty evidence). We do not know if anti-VEGFs ± PRP compared with PRP alone had an impact on adverse events (very low-certainty evidence). We did not find differences in visual acuity in subgroup analyses comparing the type of anti-VEGFs, the severity of the disease (PDR versus HRPDR), time to follow-up (< 12 months versus 12 or more months), and treatment with anti-VEGFs + PRP versus anti-VEGFs alone. The main reasons for downgrading the certainty of evidence included a high RoB, imprecision, and inconsistency of effect estimates.

AUTHORS' CONCLUSIONS

Anti-VEGFs ± PRP compared with PRP alone probably increase visual acuity, but the degree of improvement is not clinically meaningful. Regarding secondary outcomes, anti-VEGFs ± PRP produce a regression of new vessels, reduce vitreous haemorrhage, and may reduce the need for vitrectomy compared with eyes that received PRP alone. We do not know if anti-VEGFs ± PRP have an impact on the incidence of adverse events and they may have little or no effect on patients' quality of life. Carefully designed and conducted clinical trials are required, assessing the optimal schedule of anti-VEGFs alone compared with PRP, and with a longer follow-up.

Impact of HbA1c Followed 32 Years From Diagnosis of Type 1 Diabetes on Development of Severe Retinopathy and Nephropathy: The VISS Study

OBJECTIVE

To evaluate HbA1c followed from diagnosis, as a predictor of severe microvascular complications (i.e., proliferative diabetic retinopathy [PDR] and nephropathy [macroalbuminuria]).

RESEARCH DESIGN AND METHODS

In a population-based observational study, 447 patients diagnosed with type 1 diabetes before 35 years of age from 1983 to 1987 in southeast Sweden were followed from diagnosis until 2019. Long-term weighted mean HbA1c (wHbA1c) was calculated by integrating the area under all HbA1c values. Complications were analyzed in relation to wHbA1c categorized into five levels.

RESULTS

After 32 years, 9% had no retinopathy, 64% non-PDR, and 27% PDR, and 83% had no microalbuminuria, 9% microalbuminuria, and 8% macroalbuminuria. Patients with near-normal wHbA1c did not develop PDR or macroalbuminuria. The lowest wHbA1c values associated with development of PDR and nephropathy (macroalbuminuria) were 7.3% (56 mmol/mol) and 8.1% (65 mmol/mol), respectively. The prevalence of PDR and macroalbuminuria increased with increasing wHbA1c, being 74% and 44% in the highest category, wHbA1c >9.5% (>80 mmol/mol). In comparison with the follow-up done after 20-24 years' duration, the prevalence of PDR had increased from 14 to 27% and macroalbuminuria from 4 to 8%, and both appeared at lower wHbA1c values.

CONCLUSIONS

wHbA1c followed from diagnosis is a very strong biomarker for PDR and nephropathy, the prevalence of both still increasing 32 years after diagnosis. To avoid PDR and macroalbuminuria in patients with type 1 diabetes, an HbA1c <7.0% (53 mmol/mol) and as normal as possible should be recommended when achievable without severe hypoglycemia and with good quality of life.

Risk factors for having diabetic retinopathy at first screening in persons with type 1 diabetes diagnosed under 18 years of age

OBJECTIVE

To determine the risk factors for having diabetic retinopathy (DR) in children and young people (CYP) with type 1 diabetes (T1DM) at first screening.

METHODS

Records from the Diabetes Eye Screening Wales (DESW) service for people in Wales, UK, with T1DM diagnosed under age 18 years were combined with other electronic health record (EHR) data in the Secure Anonymised Information Linkage (SAIL) Databank. Data close to the screening date were collected, and risk factors derived from multivariate, multinomial logistic regression modelling.

RESULTS

Data from 4172 persons, with median (lower quartile, upper quartile) age 16.3 (13.0, 22.3) years and duration of diabetes 6.6 (2.3, 12.3) years were analysed. 62.6% (n = 2613) had no DR, 26.7% (n = 1112) background DR, and 10.7% (n = 447) had referable DR (RDR). No RDR was observed under 19 years of age. Factors associated with an increased risk of DR were diabetes duration, elevated HbA1c, and diastolic blood pressure. People diagnosed with T1DM at 12 years or older had an additional risk for each year they had diabetes compared to those diagnosed before age 12 controlling for the diabetes duration (odds ratios 1.23 and 1.34, respectively).

CONCLUSIONS

This study found that 37.4% of the study cohort had DR at first screening, the risk being greater the longer the duration of diabetes or higher the HbA1c and diastolic blood pressure. In addition, people diagnosed at 12 years of age or over were more likely to have DR with each additional year with diabetes.

Age at Diagnosis and the Risk of Diabetic Nephropathy in Young Patients with Type 1 Diabetes Mellitus

BACKGROUND

The aim of this study was to evaluate characteristics and risk of diabetic complications according to age at diagnosis among young adults with type 1 diabetes mellitus (T1DM).

METHODS

A total of 255 T1DM patients aged less than 40 years were included. Patients were categorized into three groups (<20, 20 to 29, and 30 to 40 years) according to age at diagnosis. Diabetic nephropathy (DN) was defined when spot urine-albumin creatinine ratio was 300 mg/g or more and/or estimated glomerular filtration ratio (eGFR) level was 60 mL/min/1.73 m2 or less.

RESULTS

Median age at diagnosis was 25 years and disease duration was 14 years. Individuals diagnosed with T1DM at childhood/adolescent (age <20 years) had lower stimulated C-peptide levels. They received more intensive insulin treatment with higher total daily insulin doses compared to older onset groups. The prevalence of DN was higher in the childhood/adolescent-onset group than in older onset groups (25.3% vs. 15.3% vs. 9.6%, P=0.022). The eGFR was inversely associated with disease duration whilst the degree of decrease was more prominent in the childhood/adolescent-onset group than in the later onset group (aged 30 to 40 years; P<0.001). Childhood/adolescent-onset group was independently associated with the risk of DN compared to the older onset group (aged 30 to 40 years; odds ratio, 3.47; 95% confidence interval, 1.45 to 8.33; P=0.005).

CONCLUSION

In individuals with childhood/adolescent-onset T1DM, the reduction in renal function is more prominent with disease duration. Early age-onset T1DM is an independent risk of DN.

Risk factors for prevalent diabetic retinopathy and proliferative diabetic retinopathy in type 1 diabetes

PURPOSE

Age at diagnosis of type 1 diabetes (DM1) has been implied as an important factor associated with the development of the microvascular complications. Our aim was to identify factors associated with prevalent diabetic retinopathy (DR) and proliferative diabetic retinopathy (PDR) in DM1 people with early and late-onset.

METHODS

We reviewed medical records from all DM1 people from the reference area of a tertiary center (about 340,000 persons). Univariate and multivariate logistic regression were used to assess the relationship between potential risk factors (sociodemographic, diabetes-related, co-morbidities, and laboratory parameters) and prevalent DR/PDR. We performed an analysis comparing patients diagnosed before (early-onset) and after (late-onset) 18 years of age.

RESULTS

We included 140 patients in early-onset DM1 group and 169 in late-onset DM1 group. Longer duration of diabetes and HbA1c remained associated with prevalent DR in both groups after adjusting for potential risk factors. Nephropathy was associated with prevalent DR in the late-onset group but not in the early-onset group. Peripheral neuropathy remained associated with prevalent PDR when modeled together in the multivariate model. High BMI demonstrated a significative association with PDR in early but not in the late-onset DM1 group.

CONCLUSIONS

Although previous reports suggest that age at DM1 diagnosis may have a role in DR prevalence, the risk factors for DR in early and late-onset DM1 were similar for both groups. Duration of disease and lifelong metabolic control were the major predictors for DR in both groups. Nephropathy was associated with DR in patients with late-onset disease. Neuropathy was associated with PDR occurrence in both groups. BMI was associated with PDR early-onset DM1 group.

Impact of Age of Onset, Puberty, and Glycemic Control Followed From Diagnosis on Incidence of Retinopathy in Type 1 Diabetes: The VISS Study

OBJECTIVE

To evaluate sex, age at diabetes onset, puberty, and HbA_1c, with subjects followed from diabetes diagnosis and during different time periods, as risk factors for developing diabetic simplex and proliferative retinopathy.

RESEARCH DESIGN AND METHODS

In a population-based observational study, HbA_1c for 451 patients diagnosed with diabetes before 35 years of age during 1983-1987 in southeast Sweden was followed for up to 18-24 years from diagnosis. Long-term mean weighted HbA_1c (wHbA_1c) was calculated. Retinopathy was evaluated by fundus photography and analyzed in relation to wHbA_1c levels.

RESULTS

Lower wHbA_1c, diabetes onset ≤5 years of age, and diabetes onset before puberty, but not sex, were associated with longer time to appearance of simplex retinopathy. Proliferative retinopathy was associated only with wHbA_1c. The time to first appearance of any retinopathy decreased with increasing wHbA_1c. Lower wHbA_1c after ≤5 years' diabetes duration was associated with later onset of simplex retinopathy but not proliferative retinopathy. With time, most patients developed simplex retinopathy, except for those of the category wHbA_1c ≤50 mmol/mol (6.7%), for which 20 of 36 patients were without any retinopathy at the end of the follow-up in contrast to none of 49 with wHbA_1c >80 mmol/mol (9.5%).

CONCLUSIONS

Onset at ≤5 years of age and lower wHbA_1c the first 5 years after diagnosis are associated with longer duration before development of simplex retinopathy. There is a strong positive association between long-term mean HbA_1c measured from diagnosis and up to 20 years and appearance of both simplex and proliferative retinopathy.

Analysis of Retinal Perfusion in Children, Adolescents, and Young Adults with Type 1 Diabetes Using Optical Coherence Tomography Angiography

We performed a cross-sectional study to analyze the retinal vasculature in children, adolescent, and young adults with type 1 diabetes using optical coherence tomography angiography (OCTA). Patients underwent funduscopic examination for diabetic retinopathy (DR) screening during an annual visit for the screening of diabetes-related complications which included the evaluation of glycated hemoglobin (HbA1c), microalbuminuria, lipid profile, arterial pressure, and neurological assessment. In addition, OCTA of the retinal vasculature was performed. Quantitative analysis of the OCTA images evaluated the vessel density at the superficial (SCP) and deep (DCP) capillary plexus of the retina. Structural vascular alterations were evaluated qualitatively. Results were compared to those obtained in a group of healthy age-, sex-, and pubertal stage-matched controls. The effect of age, disease duration, age at the disease onset, mean HbA1c since the onset, and lipid profile on vascular density was tested. Fifty-three patients (median age 15.5, IQR 12.4-19.4 years; 57% females) with type 1 diabetes and 48 controls were enrolled. The median (IQR) HbA1c was 7.6% (60 mmol/mol) (6.9-8.1%, 52-65 mmol/mol), and the median (IQR) duration of disease was 6.0 (3.3-10.3) years. Mean vessel density measured with OCTA was lower in patients compared to controls with the temporal sector showing the highest difference both in the SCP (0.55 vs. 0.57, p < 0.001) and the DCP (0.63 vs. 0.65, p < 0.001). None of the predictors was associated with the superficial and deep vascular densities. Only 2 patients had clinically detectable DR. Microvascular structural changes were found on OCTA in both of these patients and in one without funduscopic alterations. In conclusion, patients with type 1 diabetes without clinically detectable DR had decreased capillary density compared to controls on OCTA images. These findings may provide useful information for the screening and the management of patients with type 1 diabetes. Further studies are needed to confirm our results and their clinical relevance.

HbA1c levels in children with type 1 diabetes and correlation to diabetic retinopathy

BACKGROUND

Type 1 diabetes mellitus (T1D) is a metabolic disease causing hyperglycemia due to β-cell destruction. Despite adequate treatment, complications such as diabetic retinopathy (DR) are common. The first aim was to investigate if acute onset of type 1 diabetes differed between those who had developed retinopathy and who had not after 15 years from diagnosis. The second aim was to investigate if mean glycosylated hemoglobin (HbA1c) levels affect the time to development of DR.

METHODS

The medical records of all children and adolescents diagnosed with type 1 diabetes during 1993-2001 in our area in Sweden were studied retrospectively and the mean HbA1c each year until the development of retinopathy was investigated. In total 72 patients were included and the follow-up time was between 15 and 23 years. Gender, p-glucose, age and HbA1c at diagnosis were analyzed for possible correlations to years to retinopathy.

RESULTS

HbA1c was significantly higher among those who had developed DR after 15 years from diagnosis, 98±9.2 (n=25) vs. 86±9.2 (n=46; p=0.025). A negative correlation was found between age at diagnosis and years to DR (rs=-0.376; p=0.026). Mean HbA1c levels at years 6-10 after diabetes diagnosis correlated significantly (rs=-0.354, p=0.037) to years until retinopathy. Mean HbA1c levels at years 1-15 after diabetes diagnosis were significantly higher at years 2-3 and years 5-8 for those who had developed retinopathy after 15 years from diagnosis.

CONCLUSIONS

Higher HbA1c levels shortened the time to development of retinopathy. It is therefore important to keep HbA1c as close to normal as possible.

Cumulative Kidney Complication Risk by 50 Years of Type 1 Diabetes: The Effects of Sex, Age, and Calendar Year at Onset

OBJECTIVE

A common belief is that only a minority of patients with type 1 diabetes (T1D) develop advanced kidney disease and that incidence is higher among men and lower in those diagnosed at a younger age. However, because few patients with T1D survived to older ages until recently, long-term risks have been unclear.

RESEARCH DESIGN AND METHODS

We examined the 50-year cumulative kidney complication risk in a childhood-onset T1D cohort diagnosed during 1950-80 (n = 932; mean baseline age 29 years, duration 19 years). Participants comprised 144 who died prior to baseline, 130 followed with periodic surveys, and 658 followed with biennial surveys and a maximum of nine examinations for 25 years. Micro- and macroalbuminuria were defined as an albumin excretion rate of 20-199 and ≥200 μg/min, respectively, and end-stage renal disease (ESRD) was defined as dialysis or kidney transplantation. Cumulative incidence was estimated at 10-year intervals between 20 and 50 years^, duration and compared by calendar year of diabetes onset.

RESULTS

By 50 years^, T1D duration, ESRD affected 60% of the cohort; macroalbuminuria, 72%; and microalbuminuria, 88%. Little evidence existed for declines in cumulative incidence in recent cohorts, except for ESRD (microalbuminuria 3% increase, macroalbuminuria no change; ESRD 45% decrease by 40 years of T1D duration). Onset before age 6 years was associated with the lowest risk; incidence generally did not differ by sex.

CONCLUSIONS

Some degree of kidney disease in T1D is virtually universal at long durations and not declining, which has major implications for formulating health care and research strategies. ESRD has declined, but continues to affect >25% of the population by 40 years^, duration.

Influence of Age at Diagnosis and Time-Dependent Risk Factors on the Development of Diabetic Retinopathy in Patients with Type 1 Diabetes

Aim. To determine the influence of age at onset of type 1 diabetes and of traditional vascular risk factors on the development of diabetic retinopathy, in a cohort of patients who have been followed up after onset. Methods. Observational, retrospective study. The cohort consists of 989 patients who were followed up after diagnosis for a mean of 10.1 (SD: 6.8) years. The influence of age at diagnosis, glycemic control, duration of diabetes, sex, blood pressure, lipids, BMI, and smoking is analyzed using Cox univariate and multivariate models with fixed and time-dependent variables. Results. 135 patients (13.7%) developed diabetic retinopathy. The cumulative incidence was 0.7, 5.9, and 21.8% at 5-, 10-, and 15-year follow-up, respectively. Compared to the group with onset at age <10 years, the risk of retinopathy increased 2.5-, 3-, 3.3-, and 3.7-fold in the groups with onset at 10-14, 15-29, 30-44, and >44 years, respectively. During follow-up we also observed an association between diabetic retinopathy and HbA1c levels, HDL-cholesterol, and diastolic blood pressure. Conclusion. The rate of diabetic retinopathy is higher in patients who were older at type 1 diabetes diagnosis. In addition, we confirmed the influence of glycemic control, HDL-cholesterol, and diastolic blood pressure on the occurrence of retinopathy.

Ocular Complications in Children with Diabetes Mellitus

PURPOSE

The effectiveness of annual eye examinations in diabetic children is unclear. We sought to determine the prevalence and onset of ocular pathology in children with diabetes mellitus (DM), identify risk factors for ocular disease, and recommend a screening regimen for asymptomatic children.

DESIGN

Retrospective, consecutive cohort study.

PARTICIPANTS

Children aged less than 18 years with type 1 or 2 DM examined over a 4-year period.

METHODS

All children underwent a complete eye examination, including dilated fundoscopy and cycloplegic refraction. A literature review was performed, identifying the youngest reported age and shortest reported duration of DM before the diagnosis of diabetic retinopathy (DR).

MAIN OUTCOME MEASURES

Prevalence of DR, cataract, high refractive error, and strabismus.

RESULTS

A total of 370 children (mean age, 11.2 years; range, 1-17.5 years) had 693 examinations, with a mean DM duration of 5.2 years (range, 0.1-16.2 years) and a mean hemoglobin A1c (HbA1c) of 8.6 (range, 5-≥14). No children had DR. A total of 12 children had cataract; 5 required extraction but were identified by decreased vision, not diabetic screening. A total of 19 children had strabismus; only 1 was microvascular paralytic strabismus. A total of 41 children had high refractive error. There were no associations between these conditions and duration or control of DM. In the literature, the youngest age at diagnosis of severe DR was 15 years, and the shortest duration of disease was 5 years.

CONCLUSIONS

Diabetic retinopathy is rare in children regardless of duration and control of DM. On the basis of our study and literature review, screening examinations for type 1 diabetes could begin at age 15 years or at 5 years after the diagnosis of DM, whichever occurs later, unless the child is judged by the endocrinologist as being at unusually high risk. Other ocular complications are identifiable through existing amblyopia screening methods.

Impact of HbA1c, followed from onset of type 1 diabetes, on the development of severe retinopathy and nephropathy: the VISS Study (Vascular Diabetic Complications in Southeast Sweden)

OBJECTIVE

HbA1c is strongly related to the development of diabetes complications, but it is still controversial which HbA1c level to strive for in the treatment of type 1 diabetes. The aim of the current study was to evaluate HbA1c, followed from diagnosis, as a predictor of severe microvascular complications and to formulate HbA1c target levels for treatment.

RESEARCH DESIGN AND METHODS

A longitudinal observation study followed an unselected population of 451 patients diagnosed with type 1 diabetes during 1983-1987 before the age of 35 years in a region of Southeast Sweden. Retinopathy was evaluated by fundus photography and nephropathy data collected from medical records. HbA1c was measured starting from diagnosis and during the whole follow-up period of 20-24 years. Long-term weighted mean HbA1c was then calculated. Complications were analyzed in relation to HbA1c levels.

RESULTS

The incidence of proliferative retinopathy and persistent macroalbuminuria increased sharply and occurred earlier with increasing long-term mean HbA1c. None of the 451 patients developed proliferative retinopathy or persistent macroalbuminuria below long-term weighted mean HbA1c 7.6% (60 mmol/mol); 51% of the patients with long-term mean HbA1c above 9.5% (80 mmol/mol) developed proliferative retinopathy and 23% persistent macroalbuminuria.

CONCLUSIONS

Long-term weighted mean HbA1c, measured from diagnosis, is closely associated with the development of severe complications in type 1 diabetes. Keeping HbA1c below 7.6% (60 mmol/mol) as a treatment target seems to prevent proliferative retinopathy and persistent macroalbuminuria for up to 20 years.

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.

Prevalence of retinopathy in patients with type 1 diabetes diagnosed before and after puberty

AIMS

There is conflicting evidence to support the concept that the years with diabetes preceding puberty may not contribute to the development of vascular complications. In this paper, duration-related prevalence of retinopathy was compared in patients who developed type 1 diabetes before and after pubertal age.

METHODS

Retrospective analysis of prospectively collected data of 1,483 patients was screened for retinopathy in 1991-2010, with diabetes onset at age ≤29, who were on insulin treatment and aged ≤60. Prepubertal age was defined as 0-12 in males and 0-11 in females.

RESULTS

A total of 647 patients had developed diabetes before and 836 after puberty. Cumulative prevalence of retinopathy was initially lower among those with prepubertal onset diabetes but rates became superimposable after 20-year duration. Patients with prepubertal onset diabetes had higher lifetime HbA1c and lower blood pressure than those who became diabetic after puberty.

CONCLUSIONS/INTERPRETATION

Retinopathy is infrequent during childhood and develops later than in patients with post-pubertal onset diabetes. After 20-year duration, however, retinopathy becomes just as prevalent suggesting that, in the long term, prepubertal years do contribute to the development of retinopathy. In this series, higher blood pressure may have played a role in the earlier appearance of retinopathy in patients with diabetes onset after puberty, whereas worse metabolic control may have contributed to the late "catch-up" effect in those with prepubertal onset disease.

Anti-vascular endothelial growth factor for proliferative diabetic retinopathy

BACKGROUND

Proliferative diabetic retinopathy (PDR) is a complication of diabetic retinopathy that can cause blindness. Although panretinal photocoagulation (PRP) is the treatment of choice for PDR, it has secondary effects that can affect vision. An alternative treatment such as anti-vascular endothelial growth factor (anti-VEGF), which produces an inhibition of vascular proliferation, could improve the vision of people with PDR.

OBJECTIVES

To assess the effectiveness and safety of anti-VEGFs for PDR.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 3), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to April 2014), EMBASE (January 1980 to April 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 28 April 2014.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing anti-VEGFs to another active treatment, sham treatment or no treatment for people with PDR. We also included studies that assessed the combination of anti-VEGFs with other treatments.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data and assessed risk of bias for all included trials. We calculated the risk ratio (RR) or the mean difference (MD), and 95% confidence intervals (CI).

MAIN RESULTS

We included 18 RCTs with 1005 participants (1131 eyes) of whom 57% were men. The median number of participants per RCT was 40 (range 15 to 261). The studies took place in Asia (three studies), Europe (two studies), the Middle East (seven studies), North America (three studies) and South America (three studies). Eight RCTs recruited people eligible for PRP, nine RCTs enrolled people with diabetes requiring vitrectomy and one RCT recruited people undergoing cataract surgery. The median follow-up was six months (range one to 12 months). Seven studies were at high risk of bias and the remainder were unclear risk of bias in one or more domains.Very low quality evidence from one study of 61 people showed that people treated with bevacizumab and PRP were less likely to lose 3 or more lines of visual acuity at 12 months compared with people treated with PRP alone (RR 0.19, 95% CI 0.05 to 0.81). People treated with anti-VEGF had an increased chance of gaining 3 or more lines of visual acuity but the effect was imprecise and compatible with no effect or being less likely to gain vision (RR 6.78, 95% CI 0.37 to 125.95). No other study reported these two outcomes. On average, people treated with anti-VEGF (bevacizumab, pegaptanib or ranibizumab) had better visual acuity at 12 months compared with people not receiving anti-VEGF (MD -0.07 logMAR, 95% CI -0.12 to -0.02; 5 RCTs, 373 participants, low quality evidence). There was some evidence to suggest a regression of PDR with smaller leakage on fluorescein angiography but it was difficult to estimate a pooled result from the two trials reporting this outcome. People receiving anti-VEGF were less likely to have vitreous or pre-retinal haemorrhage at 12 months (RR 0.32, 95% CI 0.16 to 0.65; 3 RCTs, 342 participants, low quality evidence). No study reported on fluorescein leakage or quality of life.All of the nine trials of anti-VEGF before or during vitrectomy investigated bevacizumab; most studies investigated bevacizumab before vitrectomy, one study investigated bevacizumab during surgery.People treated with bevacizumab and vitrectomy were less likely to lose 3 or more lines of visual acuity at 12 months compared with people given vitrectomy alone but the effect was imprecise and compatible with no effect or being more likely to lose vision (RR 0.49, 95% CI 0.08 to 3.14; 3 RCTs, 94 participants, low quality evidence). People treated with bevacizumab were more likely to gain 3 or more lines of visual acuity (RR 1.62, 95% CI 1.20 to 2.17; 3 RCTs, 94 participants, low quality evidence). On average, people treated with bevacizumab had better visual acuity at 12 months compared with people not receiving bevacizumab but there was uncertainty in the estimate (the CIs included 0; i.e. were compatible with no effect, and there was considerable inconsistency between studies; MD -0.24 logMAR, 95% CI -0.50 to 0.01; 6 RCTs, 335 participants, I(2) = 67%; low quality evidence). People receiving bevacizumab were less likely to have vitreous or pre-retinal haemorrhage at 12 months (RR 0.30, 95% CI 0.18 to 0.52; 7 RCTs, 393 participants, low quality evidence). No study reported on quality of life.Reasons for downgrading the quality of the evidence included risk of bias in included studies, imprecision of the estimates, inconsistency of effect estimates and indirectness (few studies reported at 12 months).Adverse effects were rarely reported and there was no evidence for any increased risk with anti-VEGF but given the relatively few studies that reported these, and the low event rate, the power of the analysis to detect any differences was low.

AUTHORS' CONCLUSIONS

There was very low or low quality evidence from RCTs for the efficacy and safety of anti-VEGF agents when used to treat PDR over and above current standard treatments. However, the results suggest that anti-VEGFs can reduce the risk of intraocular bleeding in people with PDR. Further carefully designed clinical trials should be able to improve this evidence.

Neuroretinal dysfunction with intact blood-retinal barrier and absent vasculopathy in type 1 diabetes

It is unknown whether independent neural damage may occur in the pre-/absent vascular diabetic retinopathy (DR). To exclude vasculopathy, it is important to measure the integrity of the blood-retinal barrier (BRB). This cross-sectional study addressed this problem in type 1 diabetic patients with normal ocular fundus and absent breakdown of the BRB (confirmed with vitreous fluorometry). These were compared with a group with disrupted BRB (with normal fundus or initial DR) and normal controls. Multifocal electroretinography and chromatic/achromatic contrast sensitivity were measured in these 42 patients with preserved visual acuity. Amplitudes of neurophysiological responses (multifocal electroretinogram) were decreased in all eccentricity rings in both clinical groups, when compared with controls, with sensitivity >78% for a specificity level of 90%. Implicit time changes were also found in the absence of initial DR. Impaired contrast sensitivity along chromatic axes was also observed, and achromatic thresholds were also different between controls and both clinical groups. The pattern of changes in the group without baseline BRB permeability alterations, as probed by psychophysical and electrophysiological measurements, does thereby confirm independent damage mechanisms. We conclude that retinal neuronal changes can be diagnosed in type 1 diabetes, independently of the breakdown of the BRB and onset of vasculopathy.

Prevalence of vascular complications and factors predictive of their development in young adults with type 1 diabetes: systematic literature review

Background

Vascular complications curtail life expectancy and quality of life in type 1 diabetes and development at younger ages is particularly detrimental. To date no review has summarised the prevalence or factors predicting their development in young adults.

Methods

A quantitative epidemiological systematic review was conducted to identify the prevalence and predictive factors for development of retinopathy, nephropathy and hypertension in young adults (sample age mean [plus 1SD] 18–30 years) with type 1 diabetes, using processes adapted from established review methods set out by the Centre for Reviews and Dissemination.

MEDLINE (Ovid), Scopus (Elsevier), CINAHL, Science Direct (Elsevier), Google Scholar and Cochrane databases were searched to identify relevant articles published between 1993 and June 2014. From this eleven papers were retrieved, appraised and results summarised by three reviewers using established methods.

Results

Some form of retinopathy occurred in up to almost half of participants; more severe forms affected up to one in ten. One in six was reported with microalbuminuria; one in 14 had macroalbuminuria. Hypertension occurred in almost one in two participants. Applying out-dated high thresholds this decreased to approximately one in ten participants. Glycaemic control was a consistent predictor of vascular disease in this age group.

Conclusion

Prevalence rates of retinopathy, nephropathy and hypertension in young adults with type 1 diabetes emphasise the importance of regular complication screening for early detection and treatment. The predictive effect of glycaemic control reinforces its importance for prevention of vascular complications.

Electronic supplementary material

The online version of this article (doi:10.1186/1756-0500-7-593) contains supplementary material, which is available to authorized users.

Prevalence and healthcare costs of diabetic retinopathy: a population-based register study in Sweden

AIMS/HYPOTHESIS

The aim of the present study was to estimate the prevalence and healthcare costs of diabetic retinopathy (DR).

METHODS

This population-based study included all residents (n = 251,386) in the catchment area of the eye clinic of Linköping University Hospital, Sweden. Among patients with diabetes (n = 12,026), those with and without DR were identified through register data from both the Care Data Warehouse in Ostergötland, an administrative healthcare register, and the Swedish National Diabetes Register. Healthcare cost data were elicited by record linkage of these two registers to data for the year 2008 in the Cost Per Patient Database developed by Ostergötland County Council.

RESULTS

The prevalence of any DR was 41.8% (95% CI 38.9-44.6) for patients with type 1 diabetes and 27.9% (27.1-28.7) for patients with type 2 diabetes. Sight-threatening DR was present in 12.1% (10.2-14.0) and 5.0% (4.6-5.4) of the type 1 and type 2 diabetes populations respectively. The annual average healthcare cost of any DR was euro72 (euro53-91). Stratified into background retinopathy, proliferative DR, maculopathy, and the last two conditions combined, the costs were euro26 (euro10-42), euro257 (euro155-359), euro216 (euro113-318) and euro433 (euro232-635) respectively. The annual cost for DR was euro106,000 per 100,000 inhabitants.

CONCLUSIONS

This study presents new information on the prevalence and costs of DR. Approximately one-third of patients with diabetes have some form of DR. Average healthcare costs increase considerably with the severity of DR, which suggests that preventing progression of DR may lower healthcare costs.

[Diabetic retinopathy risk factors]

Diabetic retinopathy (DR) occurs in about 95% of patients with type 1 diabetes mellitus (DM) and in 60% of type 2 DM patients and it is the main cause of legal blindness in adult people. The aim of this manuscript was to review the main risk factors for DR. The major environmental risk factors are hyperglycemia, high blood pressure levels, and long-term duration of DM. However, not all patients will not develop DR, suggesting the presence of a genetic predisposition to DR, especially for severe forms of DR. Special strategies has been used to evaluate the genetic role in DR. Family studies shown that there is a familial aggregation of DR. Candidates genes have been studied (RAGE; VEGF; PPAR-delta; ICAM-1; ECA; ENPP 1; eNOS) and positive or negative associations with DR were demonstrated. Some chromosomes were also associated to DR in selected populations. Finally, genetic expression studies reinforce the association of candidate genes, or participation of others genes, with the presence of DR. DR is a common complication of DM and, along with non-genetic or environmental risk factors, the identification of genes related to DR could result in more specific and efficient DR treatment.

Prevalence of diabetic retinopathy in children and adolescents with type-1 diabetes attending summer camps in France

OBJECTIVE

To evaluate, using fundus photography, the prevalence of diabetic retinopathy (DR) in young diabetic subjects attending summer camps run by the Aide aux Jeunes Diabétiques Association (Aid to Young Diabetics).

RESEARCH DESIGN AND METHODS

Five hundred and four children and adolescents (250 boys and 254 girls), with type 1 diabetes mellitus, aged 10-18 years (mean:13+/-2), were screened for DR using non mydriatic photography, during their stay in a holiday camp. Demographic and clinical data recorded on subjects' arrival in the camp included date of birth, height, weight, treatment, blood pressure, and duration of diabetes. HbA(1c) was determined with a DCA 2000 kit.

RESULTS

Mean diabetes duration was 4.8+/-3.4 years and mean HbA(1c) was 8.5+/-1.3%. Mild non proliferative DR was diagnosed in 23 children (4.6%). Compared to subjects without DR, those with DR were significantly older (P<10(-3)), had a longer duration of diabetes (P=0.001), higher systolic blood pressure (P=0.04), and had higher (but not significantly so) HbA(1c) (P=0.15). After adjustment for age, only longer duration remained significantly associated with DR (P=0.01).

CONCLUSION

The prevalence of DR in these young patients was low compared to that reported in previous studies. The decrease may be due to modern diabetes care with multiple insulin injections. However, early detection of DR in adolescents, especially in their late teens, remains important, because it allows the identification of patients at high risk of progression towards severe stages of DR.

Diabetes care, glycemic control, and complications in children with type 1 diabetes from Asia and the Western Pacific Region

AIMS

The incidence of type 1 diabetes is increasing in many parts of Asia, where resources may not enable targets for glycemic control to be achieved. The aims of this study were to describe glycemic control, diabetes care, and complications in youth with type 1 diabetes from the Western Pacific Region and to identify factors associated with glycemic control and hypoglycemia.

METHODS

A cross-sectional clinic-based study on 2312 children and adolescents (aged <18 years; 45% males) from 96 pediatric diabetes centers in Australia, China, Hong Kong, Indonesia, Japan, Malaysia, Philippines, Singapore, South Korea, Taiwan, and Thailand was conducted. Clinical and management details were recorded, and finger-pricked blood samples were obtained for central glycated hemoglobin (HbA(1c)).

RESULTS

The median age of the patients was 12.5 years [interquartile range (IQR)=9.4-15.3 years]; diabetes duration, 4.4 years (IQR=2.5-7.2 years); and HbA(1c) level, 8.3% (IQR 7.4%-9.7%). Insulin treatment consisted of one or two daily injections in 61% of the patients (range=22%-90% by country), and home blood glucose monitoring (range=67%-100%) was practiced by 96%. HbA(1c) level was significantly associated with country, age, diabetes duration, sex, insulin dose per kilogram, insulin regimen, and frequency of home blood glucose measurement in multiple regression analysis. The incidence of severe hypoglycemia, defined as any episode requiring assistance in the previous 3 months, was 73 per 100 patient-years and was associated with country, male sex, higher HbA(1c) level, an insulin regimen with three or more injections, and more frequent home blood glucose testing. The incidence of diabetic ketoacidosis was 10 per 100 patient-years and was associated with country, higher HbA(1c) level, and higher insulin dose per kilogram.

CONCLUSIONS

There is marked variability in glycemic control, hypoglycemia, complication rates, and diabetes care among children from the Western Pacific Region. Most are not achieving adequate glycemic control, placing them at high risk of microvascular complications.

Age at onset of childhood-onset type 1 diabetes and the development of end-stage renal disease: a nationwide population-based study

OBJECTIVE

To analyze the impact of age at onset on the development of end-stage renal disease (ESRD) due to diabetic nephropathy in a nationwide population-based cohort with childhood-onset type 1 diabetes.

RESEARCH DESIGN AND METHODS

A record linkage between two nationwide registers, the Swedish Childhood Diabetes Registry, including 12,032 cases with childhood-onset diabetes, and the Swedish Registry for Active Treatment of Uraemia was performed. Log-rank test was used to test differences between cumulative risk curves of developing ESRD due to diabetic nephropathy in three different strata of age at onset (0-4, 5-9, and 10-14 years).

RESULTS

At a maximum follow-up of 27 years, 33 patients had developed ESRD due to diabetic nephropathy and all had a diabetes duration >15 years. In total, 4,414 patients had diabetes duration >15 years, and thus the risk in this cohort to develop ESRD was 33 of 4,414 (0.7%). A significant difference in risk of developing ESRD was found between the youngest (0-4 years) and the two older (5-9 and 10-14 years) age-at-onset strata (P = 0.03 and P = 0.001, respectively). A significant difference in the risk of developing ESRD was also found between children with prepubertal (0-4 and 5-9 years, n = 2,424) and pubertal (10-14 years, n = 2000) onset of diabetes (P = 0.002). No patient with onset of diabetes before 5 years of age had developed ESRD.

CONCLUSIONS

With a median duration of 21 years in this population-based Swedish cohort with childhood-onset diabetes, <1% of the patients had developed ESRD due to diabetic nephropathy, and a prepubertal onset of diabetes seems to prolong the time to development of ESRD.

Prevalence of diabetes complications 6 years after diagnosis in an incident cohort of childhood diabetes

AIMS

To examine the prevalence of early diabetes complications 6 years after diagnosis of diabetes. The hypothesis that initial contact with a multidisciplinary team would be associated with a reduced risk of microvascular complications was tested in this cohort.

METHODS

Participants were recruited from an incident cohort of children aged < 15 years diagnosed between 1990 and 1992 in NSW, Australia. Initial management at a teaching hospital was documented at case notification. At 6 years, health care questionnaires and complications were assessed: retinopathy by 7-field stereoscopic retinal photography and elevated albumin excretion rate (AER) defined as the median of three overnight urine collections > or = 7.5 microg/min. Case attainment was 58% (209/361) with participants younger than non-participants and more likely living in an urban than rural location.

RESULTS

Retinopathy was present in 24%, median AER > or = 7.5 microg/min in 18%, and median AER > or = 20 microg/min in 2%. In multivariate analysis, initial management at a teaching hospital or consultation with all three allied health professionals combined with pubertal staging and cholesterol or HbA1c were all determinants of risk for retinopathy.

CONCLUSIONS

Early retinopathy and elevated AER are common in children 6 years after diagnosis. Initial allied health contact and management at a teaching hospital were associated with a reduced risk of microvascular complications in this cohort.

Un autre regard sur les implications de l’étude DCCT

The fundamental role of good metabolic control has been demonstrated in type 1 and type 2 diabetes. Nevertheless, clinicians often wonder why some patients under good metabolic control develop complications while others remain free of such complications, despite a poorly controlled disease. The present study revisited material from the DCCT database, by classifying the 1441 patients as being under good or poor metabolic control if their HbA1c mean level fell in the lower (HbA1c<=6.9%) or upper (HbA1c>/=9.5%) quintile of the overall distribution of mean HbA1c levels observed in the DCCT population. The impact of metabolic control and of other potential factors related to the patient and his/her disease on the development and/or deterioration of complications, in particular diabetic retinopathy and nephropathy, was assessed. Although metabolic control is the major determinant of the risk of developing diabetic retinopathy and nephropathy, the study also emphasizes the significant role of other risk factors, in particularly BMI, disease duration, micro-albuminuria, HbA1c at baseline, gender and age on such complications. It is concluded that early control of the metabolic and clinical status of diabetic patients has major consequences on the evolution of the disease. Nomograms have been proposed to help the clinician in this task.

Pre-pubertal onset of type 1 diabetes and appearance of retinopathy

OBJECTIVES

It was suggested that the years of diabetes preceding puberty may not contribute to the development of retinopathy but evidence for this is conflicting. To verify the influence of pre-pubertal diabetes, we compared the correlations between prevalence of retinopathy and diabetes duration in patients who developed type 1 diabetes before and after puberty.

METHODS

Six hundred and twenty-eight patients with diabetes onset at age< or =29, on insulin treatment and aged< or =60 at the time of screening for retinopathy were considered retrospectively. Pre-pubertal age was defined as 0-12 in males and 0-11 in females. Two hundred patients had developed diabetes before puberty and 428 after puberty. Screening was by ophthalmoscopy + 35 mm photography or digital photography.

RESULTS

Prevalence of retinopathy was lower among patients with pre-pubertal onset and diabetes durations 10-14 and 15-19 years (p=0.006 and p=0.003, respectively) but prevalence rates became similar after 20 yrs duration.

CONCLUSION

That retinopathy is infrequent and mild during childhood, is probably due to the short duration of diabetes rather than a specific protective effect of pre-puberty. After 20 years' duration, however, the prevalence of retinopathy is no longer influenced by age at onset, suggesting that, in the longer term, pre-pubertal years do contribute to the onset of retinopathy.