Prevalence and development of retinopathy in children and adolescents with type 1 (insulin-dependent) diabetes mellitus. A longitudinal study

Long-term tracking of glycosylated hemoglobin levels across the lifespan in type 1 diabetes: from infants to young adults

PURPOSE

Glycosylated hemoglobin (HbA1c) is commonly used as a monitoring tool in diabetes. Due to the potential influence of insulin resistance (IR), HbA1c level may fluctuate over a person's lifetime. This study explores the long-term tracking of HbA1c level in individuals diagnosed with type 1 diabetes mellitus (T1DM) from infancy to early adulthood.

METHODS

The HbA1c levels in 275 individuals (121 males, 43.8%) diagnosed with T1DM were tracked for an average of 9.4 years. The distribution of HbA1c levels was evaluated according to age with subgroups divided by gender, use of continuous glucose monitoring (CGM), and the presence of complications.

RESULTS

HbA1c levels were highest at the age of 1 year and then declined until age 4, followed by a significant increase, reaching a maximum at ages 15-16 years. The levels subsequently gradually decreased until early adulthood. This pattern was observed in both sexes, but it was more pronounced in females. Additionally, HbA1c levels were higher in CGM nonusers compared with CGM users; however, regardless of CGM usage, an age-dependent pattern was observed. Furthermore, diabetic complications occurred in 26.8% of individuals, and the age-dependent pattern was observed irrespective of diabetic complications, although HbA1c levels were higher in individuals with diabetic complications.

CONCLUSION

HbA1c levels vary throughout the lifespan, with higher levels during adolescence. This trend is observed regardless of sex and CGM usage, potentially due to physiological IR observed during adolescence. Hence, physiological IR should be considered when interpretating HbA1c levels during adolescence.

Present and future screening programs for diabetic retinopathy: a narrative review

Diabetes is a prevalent global concern, with an estimated 12% of the global adult population affected by 2045. Diabetic retinopathy (DR), a sight-threatening complication, has spurred diverse screening approaches worldwide due to advances in DR knowledge, rapid technological developments in retinal imaging and variations in healthcare resources.Many high income countries have fully implemented or are on the verge of completing a national Diabetic Eye Screening Programme (DESP). Although there have been some improvements in DR screening in Africa, Asia, and American countries further progress is needed. In low-income countries, only one out of 29, partially implemented a DESP, while 21 out of 50 lower-middle-income countries have started the DR policy cycle. Among upper-middle-income countries, a third of 59 nations have advanced in DR agenda-setting, with five having a comprehensive national DESP and 11 in the early stages of implementation.Many nations use 2-4 fields fundus images, proven effective with 80-98% sensitivity and 86-100% specificity compared to the traditional seven-field evaluation for DR. A cell phone based screening with a hand held retinal camera presents a potential low-cost alternative as imaging device. While this method in low-resource settings may not entirely match the sensitivity and specificity of seven-field stereoscopic photography, positive outcomes are observed.Individualized DR screening intervals are the standard in many high-resource nations. In countries that lacks a national DESP and resources, screening are more sporadic, i.e. screening intervals are not evidence-based and often less frequently, which can lead to late recognition of treatment required DR.The rising global prevalence of DR poses an economic challenge to nationwide screening programs AI-algorithms have showed high sensitivity and specificity for detection of DR and could provide a promising solution for the future screening burden.In summary, this narrative review enlightens on the epidemiology of DR and the necessity for effective DR screening programs. Worldwide evolution in existing approaches for DR screening has showed promising results but has also revealed limitations. Technological advancements, such as handheld imaging devices, tele ophthalmology and artificial intelligence enhance cost-effectiveness, but also the accessibility of DR screening in countries with low resources or where distance to or a shortage of ophthalmologists exists.

Are we overlooking the neurodegeneration in the early stage of Type 1 Diabetes Mellitus without Visual Impairment or Diabetic Retinopathy: is it probably occurred before retinal vasculature dysfunction?

PURPOSE

Using electrophysiology (ERG) to investigate the early alterations of retinal function in diabetic children and adolescents without diabetic retinopathy (DR) or visual impairment (VI).

METHODS

We recorded and compared the data of full-field flicker ERGs between 59 normal subjects and 60 children and adolescents with type 1 diabetes mellitus (T1DM) from the Children's Hospital of Fudan University in Shanghai.

RESULTS

In both groups, patients with diabetes and healthy controls were matched for age, gender, weight, height, BMI, intraocular pressure (IOP), and best-corrected visual acuity (BCVA). Among the parameters of the outcomes of ERG, the implicit time in eyes in DM patients was significantly prolonged compared to normal eyes (p = .008, 16 Td-s; p = .000, 32 Td-s). In the case group, we found significantly positive correlation between implicit time and BMI (p < .05), as well as implicit time and axial length (AL).

CONCLUSIONS

The study reveals that the dysfunction of retina in DM children can be detected with ERGs. It also shows that hyperglycemia has an impact on the occurrence of neurodegeneration in the early stage of DM.

Screening for diabetic retinopathy with fluorescein angiography in patients with type 1 diabetes from adolescence to adult life. A retrospective study of the past 30 years of clinical practice in a tertiary Belgian centre

Background

The aim of the present study was to describe the prevalence and progression of DR diagnosed by fluorescein angiography (FA) in patients with type 1 diabetes (T1D) during a 30‐year follow‐up, and the relationship with glycated haemoglobin (HbA1c).

Materials and methods

We included 4325 FA reports representing 851 patients with T1D with a mean age at diagnosis of 10.4 years (range: 0.0–49.9) and followed between 1986 and 2015. Clinical characteristics of the population were collected from patients’ files. The HbA1c level was measured within a maximum period of ±1 year from the date of FA. Descriptive statistics were realized to study prevalence and progression of DR.

Results

At diagnosis of incipient abnormalities, mean age was 22.8 years (range 13.7–46.9) and mean diabetes duration was 13 years (range: 4.3–29.6). Lesions requiring treatment were observed in 5.9% of the patients at a mean age of 32.4 years (range: 30.4–34.3) and a mean diabetes duration of 23.8 years (range: 19.4–28.1). On average, it took 12.9 years (range: 12.2–13.5) to progress from an incipient abnormality to a lesion requiring treatment. Mean HbA1c ± SD was 7.8 ± 1.5% over a period of 30 years.

Conclusions

While it could have been expected to observe a higher prevalence of DR, our study described by far the lowest results of prevalence comparing to similar studies, probably due to a good average HbA1c over 30 years.

Choroidal thickness in children with type 1 diabetes depending on the pubertal status and metabolic parameters analyzed by optical coherence tomography

To assess choroidal thickness (CT) in children with type 1diabetes (T1D) regarding their pubertal status and seek for factors influencing this parameter, using optical coherence tomography.

MATERIAL AND METHODS

333 eyes out of 167 children with T1D without symptoms of diabetic retinopathy (mean age 12.81 ± 3.63 years, diabetes duration 4.59 ± 3.71 years) were enrolled. CT in all quadrants was evaluated. The studied population was divided into three groups: prepubertal, pubertal and postpubertal. The multivariate regression model was carried out using all metabolic parameter and then it was built using only the significant ones.

RESULTS

Significant differences in CT between males and females, except nasal and superior quadrants were observed. We revealed significant differences in CT between the three independent groups (Chi-square 18.6, p < 0.0001). In the statistically significant multiple regression model (R = 0.9, R² = 0.82, p < 0.0000), the serum level of free thyroxine, triiodothyronine, total hemoglobin, uric acid, low- and high-density cholesterol, daily insulin dose per kilogram, weight and level of vitamin D were significant.

CONCLUSION

In our studied group CT increases during puberty. Metabolic parameters such as cholesterol, uric acid, thyroid hormones, and hemoglobin concentration even within the normal range, significantly influence the CT, and these factors likely affect other blood vessels in the body.

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.

SCREENING FOR DIABETIC RETINOPATHY - A TWELVE-MONTH REVIEW

The purpose is to provide a twelve-month database review of screening for diabetic retinopathy (DR). A total of 1428 diabetes mellitus (DM) patients screened in 2017 were analyzed in a retrospective study. Retinal photographs were reviewed by an ophthalmologist for the presence and stage of DR, as well as for additional nondiabetic findings. The following grading categories of DR were used: without DR, mild non-proliferative DR (NPDR), moderate NPDR, severe non-proliferative NPDR, proliferative DR (PDR), clinically significant macular edema (CSME) and ungradable finding. Severe NPDR, PDR and CSME were classified as vision-threatening DR. Out of 1428 DM patients, 27 were diagnosed with type 1 DM and 1401 with type 2 DM, 353 of them had newly diagnosed type 2 DM. Without DR category was recorded in 85.2% of all eyes screened, 2.8% were ungradable, and 12% showed varying stages of DR. Vision-threatening DR was found in 2.8% and additional nondiabetic findings in 5.2% of all screened eyes. In the group of newly diagnosed type 2 DM, 92.5% of screened eyes were without DR, 3.1% were ungradable and 4.3% showed varying stages of DR. In the group of newly diagnosed type 2 DM, vision-threatening DR was recorded in 0.1% and additional nondiabetic finding in 5.7% of the eyes screened. In conclusion, a small proportion of screened DM patients with detected DR had vision-threatening DR.

Retinal Microvascular Abnormalities in Children with Type 1 Diabetes Mellitus Without Visual Impairment or Diabetic Retinopathy

Purpose

To study the characteristics and associated factors of retinal microvascular abnormalities in children with type 1 diabetes mellitus (T1DM) without visual impairment and diabetic retinopathy (DR).

Methods

Case-control hospital-based study including children with or without DM. Optical coherence tomography angiography (OCTA; CIRRUS HD-OCT model 5000) was used to scan 6 × 6 mm square area of posterior retina and optic disc. The indexes analyzed mainly included vascular length density (VD), perfusion density (PD), and foveal avascular zone area, perimeter, and morphology. Independent risk factors were analyzed by multifactor linear regression.

Results

A total of 47 children with T1DM and 44 healthy subjects were enrolled. Statistical analysis showed that VD within 1 to 3 mm (inner ring) of the macula in the case group was smaller than that in the control group (18.561 ± 1.151/mm: 19.161 ± 0.464/mm; P< 0.001), and mother's excessive weight gain during pregnancy was an independent factor (P = 0.004); VD within 3 to 6 mm (outer ring) of the macula in the case group was smaller than that in the control group (19.044 ± 0.847/mm; 19.404 ± 0.496/mm, P = 0.029), while serum creatinine level was revealed to be an independent factor (P = 0.009); PD within 3 to 6 mm of the macula in the case group was higher than that in the control group (0.456 ± 0.015: 0.442 ± 0.030) (P = 0.003), with no independent factor observed in regression analysis.

Conclusion

Retinal microvasculopathy had already occurred in the parafoveal area of diabetic children without visual impairment and DR; early screening and close follow-up were recommended for children with high-risk factors.

Prevalence and risk factors for diabetic retinopathy in a hospital-based population of Australian children and adolescents with type 1 diabetes

BACKGROUND

The aim of this study was to investigate the prevalence of, and traditional and emerging risk factors associated with, retinopathy in a hospital-based population of Australian children and adolescents with type 1 diabetes.

METHODS

This was a cross-sectional study of 483 children and adolescents with type 1 diabetes. Medical files were audited to collect all relevant clinical data. Diabetic retinopathy was assessed from colour retinal images by an ophthalmologist.

RESULTS

Diabetic retinopathy was observed in 11 (2.3%) participants. Logistic regression revealed that the principal components analysis derived risk profile of: higher serum creatinine, older age, higher systolic blood pressures, higher body mass index, abnormal estimated glomerular filtration rate (eGFR) (<59 mL/min), lower high density lipoproteins (HDL) cholesterol, higher serum sodium, longer duration of diabetes and narrower retinal arteriolar calibre was associated with diabetic retinopathy (ExpB=2.60, 95% CI 1.36/4.96, p=0.004).

CONCLUSIONS

These results support the concept that the pathogenesis of diabetic retinopathy is likely due to the combined influence of various risk factors, many already identified.

Diagnosis of retinopathy in children younger than 12 years of age: implications for the diabetic eye screening guidelines in the UK

AimTo assess whether the current starting age of 12 is suitable for diabetic retinopathy (DR) screening and whether diabetes duration should be taken into account when deciding at what age to start screening patients.Materials and methodsA retrospective analysis of 143 patients aged 12 years or younger who attended diabetic eye screening for the first time in the Birmingham, Solihull and Black Country Diabetic Eye Screening Programme was performed.ResultsThe mean age of the patients was 10.7 (7-12) years with 73 out of 143 aged below 12 years and 70 were 12 years of age. 98% had type 1 diabetes and mean diabetes duration was 5 (1 month-11 years) years. For those younger than 12 years, 7/73 (9.6%) had background DR (BDR), of these mean diabetes duration was 7 years (6-8). The youngest patient to present with DR was aged 8 years. In those aged 12 years, 5/70 (7.1%) had BDR; of these mean diabetes duration was 8 years (6-11). No patient developed DR before 6 years duration in either group.ConclusionsThe results show that no patient younger than the age of 12 had sight-threatening DR (STDR), but BDR was identified. Based on the current mission statement of the Diabetic Eye Screening Programme to identify STDR, 12 years of age is confirmed as the right age to start screening, but if it is important to diabetic management to identify first development of DR, then screening should begin after 6 years of diabetes diagnosis.

Puberty as an accelerator for diabetes complications

Much is written about how difficult it is to deal with diabetes during adolescence, and rightly so. Less is understood as to how puberty may be an accelerator of vascular complications. With the increase in childhood diabetes, complication risks need to be revisited in relation to puberty and the secular increase in adiposity. Recent data suggest greater risk for severe vascular complications in those with diabetes during puberty, compared with young people who develop diabetes after puberty. It is also widely recognized that higher hemoglobin A1c (HbA1c) results are often seen during the pubertal period. This article will review complication outcomes in relation to puberty and examine mechanisms by which puberty may modify risk above glycemic exposure, and possible gender disparities in the risk of complications in the adolescent period.

Epidemiological issues in diabetic retinopathy

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

Retrospective comparative analysis of metabolic control and early complications in familial and sporadic type 1 diabetes patients

BACKGROUND

Genetic susceptibility and lifestyle are associated with glycemic control and diabetic complications in type 1 diabetes (T1D).

OBJECTIVES

To investigate metabolic control and occurrence of acute and microvascular complications among familial and sporadic T1D patients.

PATIENTS AND METHODS

Retrieved from our institutional registry of new T1D cases for the years 1979-2008 were 226 familial patients belonging to 121 families (58 parent-offspring, 63 sib-pairs) and 226 sporadic cases matched for age, gender, and year of diagnosis. Extracted from medical files were clinical course and therapeutic regimen.

RESULTS

Mean age at diagnosis of diabetes of the cohort was 10.8 ± 5.7 years. Throughout follow-up (11.1 ± 8.7 years) mean HbA1c values were significantly higher in familial than in sporadic cases (8.18%± 1.15% vs. 7.85%± 1.15%, p=0.005). Diabetic ketoacidosis (DKA) rates were higher in familial than sporadic cases (2.8 vs. 1.9 events per 100 patient-years; incidence rate ratio (IRR)=1.5, 95% CI [1.03, 2.22, p=0.03]). Severe hypoglycemia events per 100 patient-years were comparable in familial and sporadic groups (3.7 vs. 4.0 events); sib-pairs had higher rates than parent-offspring (4.8 vs. 2.4 events; (IRR)=2, 95% CI [1.03, 3.25, p=0.03]). The percentage of patients with microvascular complications was similar in the familial (21.7%) and sporadic (26.7%) groups. In both familial and sporadic cases the most significant predictor for metabolic control and microvascular complications was diabetes duration; a higher mean HbA1c level was the predictor for DKA events.

CONCLUSIONS

The worse metabolic control and increased rate of DKA in familial T1D patients as compared to those in the sporadic T1D patients warrant intensified surveillance in this population.

Prevalence of diabetic retinopathy in various ethnic groups: a worldwide perspective

The alarming rise in diabetes prevalence is a global public health and economic problem. Diabetic retinopathy is the most common complication of diabetes and the leading cause of blindness among working-age populations in the Western world. Screening and prompt treatment of diabetic retinopathy are not top priorities in many regions of the world, because the impacts of other causes of preventable blindness remain an issue. Ethnicity is a complex, independent risk factor for diabetic retinopathy. Observations from white populations cannot be extrapolated fully to other ethnic groups. The prevalence of diabetic retinopathy, sight-threatening diabetic retinopathy, and clinically significant macular edema are higher in people of South Asian, African, Latin American, and indigenous tribal descent compared to the white population. Although all ethnic groups are susceptible to the established risk factors of diabetic retinopathy-such as length of exposure and severity of hyperglycemia, hypertension, and hyperlipidemia-ethnic-specific risk factors also may influence these rates. Such risk factors may include differential susceptibility to conventional risk factors, insulin resistance, differences in anthropometric measurements, truncal obesity, urbanization, variations in access to healthcare systems, genetic susceptibility, and epigenetics. The rates of nonproliferative diabetic retinopathy appear to be declining in the United States, supporting the observation that better medical management of diabetes and prompt treatment of sight-threatening diabetic retinopathy substantially improve the long-term diabetic retinopathy incidence; studies from other parts of the world are limited and do not mirror this finding, however. We examine the ethnicity and region-based prevalence of diabetic retinopathy around the world and highlight the need to reinforce ethnicity-based screening and treatment thresholds in diabetic retinopathy.

Multifocal ERG defects associated with insufficient long-term glycemic control in adolescents with type 1 diabetes

PURPOSE

To investigate the relationship between long-term glycemic control and localized neuroretinal function in adolescents with type 1 diabetes (T1D) without diabetic retinopathy (DR).

METHODS

Standard (103 hexagons) and slow-flash (61 hexagons) multifocal ERGs (standard mfERG and sf mfERG) were recorded in 48 patients and 45 control subjects. Hexagons with delayed responses were identified as abnormal. Negative binomial regression analysis was conducted with the number of abnormal hexagons as the outcome variable. Glycated hemoglobin (HbA(1c)) levels, time since diagnosis of T1D, age at diagnosis of T1D, age at testing, and sex were the covariates. Another model replacing HbA(1c) closest to the date of testing with a 1-year average was also generated.

RESULTS

There were more abnormal hexagons for mfOPs in patients than in control subjects (P = 0.005). There was no significant difference in the mean number of abnormal hexagons for standard mfERG responses between patients and control subjects (P = 0.11). Negative binomial regression analysis for the standard mfERG data demonstrated that a 1-unit increase in HbA(1c) was associated with an 80% increase in the number of abnormal hexagons (P = 0.002), when controlling for age at testing. Analysis using the 1-year HbA(1c) averages did not result in significant findings.

CONCLUSIONS

Poor long-term glycemic control is associated with an increase in areas of localized neuroretinal dysfunction in adolescents with T1D and no clinically visible DR. Stricter glucose control during the early stages of the disease may prevent neuroretinal dysfunction in this cohort.

Juvenile diabetes eye complications and treatment

BACKGROUND/AIM

Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia. The aim of this study was to explore the prognosis of patients with juvenile DM regarding diabetic eye complications, as well as the course of the diabetic eye disease related to the treatment undertaken.

METHODS

The study series involved 33 patients with juvenile DM during the period 1992-2007. The influence of the following factors on the course of the disease was estimated: age, the age of the disease onset, time when eye complications appeared, treatment modalities.

RESULTS

Of the total of 33 diabetics 15 patients were followed for 10 or more years and 18 from 5 to 9 years. At the time of their first visit the mean age was 23.12 +/- 6.39 and the mean duration of DM was 17.42 +/- 7.42 years. On their first visit, 7 eyes were without any complication. Most of the patients already developed clinical signs of proliferative diabetic retinopathy (41.39%), the signs of nonproliferative diabetic retinopathy (13.13%) and macula involvement (10.10%). Diabetic cataract was found in 8.8% as well as tractional retinal detachment. Eleven out of 66 eyes were with vitreous hemorrhage. Two patients (5.5%) suffered neovascular glaucoma. There was 1 (2.2%) patient with developed rubeosis iridis and simplex glaucoma. Panretinal photocoagulation was performed in 65% of patients, focal photocoagulation in 15%, 12% patients underwent pars plana vitrectomy and 4% had cataract surgery with intraocular lens implantation and peripheral retinal kryopexy.

CONCLUSION

Total vision loss due to eye complications of juvenile DM may be prevented if timely diagnosed with regular check ups and early treatment.

[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.

Article Commentary: The English national screening programme for sight-threatening diabetic retinopathy

Objectives

The main objective of the national screening programme is to reduce the risk of sight loss among people with diabetes due to diabetic retinopathy (DR).

Methods

Offering two-field mydriatic digital photographic screening to all people with diabetes in England over the age of 12 years.

Stage of development

The programme is in its infancy, receiving the first year's annual reports from approximately 96 screening programmes, each of which have developed to offer screening to a minimum number of 12,000 people with diabetes, which would cover a population of 350,000 people with 3.4% diabetes prevalence. The national programme has commenced the External quality assurance (QA) programme in order to achieve and sustain the highest possible standards.

Potential benefits

England has a population of two million people with diabetes over the age of 12 and it is believed that there is a prevalence of blindness of 4200 and an annual incidence of blindness of 1280 people with diabetes. This programme has the potential to reduce the prevalence of blindness in England from 4200 people to 1000 people and a conservative estimate of reducing the annual incidence of DR blindness by one-third would save 427 people per annum from blindness. These figures are based on the UK certification of blindness but if World Health Organization (WHO) definitions are used the prevalence, incidence and potential reductions in blindness are much greater.

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.

Glycaemic control, markers of endothelial cell activation and oxidative stress in children with type 1 diabetes mellitus

BACKGROUND

The aim of this study was to compare the effect of glycaemic control on oxidative stress and biochemical markers of endothelial activation in type 1 diabetic children.

METHODS

Serum total cholesterol, HDL cholesterol, VLDL cholesterol, apolipoprotein A1, apolipoprotein B, HbA(1c), MDA, VEGF, NO, ICAM levels were assessed in 100 children with type 1 DM aged 2-17 years. Study cases were evaluated in three groups in view of their mean HbA(1c) values, as metabolically well-controlled (HbA(1c)< or =8%) and poorly controlled (HbA(1c)>8%) patients with DM and 40 healthy children were included as normal controls.

RESULTS

Levels of MDA, NO, VEGF, ICAM, apolipoprotein A1 and apolipoprotein B in metabolically poorly controlled diabetic patients were significantly higher than control group (P<0.05). In correlation analysis of HbA(1c) to VEGF, no significant correlations were detected in metabolically well-controlled DM, but there were significant correlations between HbA(1c) and NO, MDA, ICAM levels. In correlation analysis of HbA(1c) to VEGF, NO, MDA and ICAM levels, significant correlations were detected in poorly controlled diabetics (P<0.05).

CONCLUSIONS

In the present study, increased levels of MDA, NO, ICAM-1 and VEGF levels showed that especially metabolically poorly controlled DM children are at high risk of atherosclerosis and vascular complications of DM and that there is a significant relationship between HbA(1c) and oxidative stress. It may be appropriate to evaluate levels of VEGF and sICAM-1 as well as markers of oxidative stress in addition to routine laboratory assessments in evaluation of type 1 DM pediatric patients.

Lower-than-expected prevalence and severity of retinopathy in an incident cohort followed during the first 4-14 years of type 1 diabetes: the Wisconsin Diabetes Registry Study

The authors examined the development of diabetic retinopathy in a population-based cohort of persons with incident type 1 diabetes to investigate the possibility of lowered retinopathy prevalence and severity compared with previous US studies. A total of 474 diabetic persons from Wisconsin were followed from diagnosis through 4-14 years' duration during 1990-2002. Retinopathy was determined by fundus photography at 4, 7, 9, and 14 years' duration. Risk of developing retinopathy was modeled on demographic and diabetes-care characteristics by means of a generalized linear model using the complementary log-log link for interval-censored data. Prevalence of retinopathy increased with duration of diabetes, from 6% at 4 years to 73% at 14 years, and was highest among adults (> or =20 years of age). Risk of developing retinopathy increased with increasing duration, worse glycemic control, and age up to 20 years. Indicators of diabetes care were related to retinopathy through their effect on glycemic control. Improvements in diabetes care leading to better glycemic control may have contributed to the much lower prevalence and less severe retinopathy observed than expected on the basis of a previous report from the same region of Wisconsin. The observed decreased prevalence has important implications for persons with type 1 diabetes, since retinopathy is a serious microvascular complication.

Early diabetic complications in a population of young patients with type 1 diabetes mellitus despite intensive treatment

AIM

To describe the prevalence of early complications in an unselected population of patients with type 1 diabetes mellitus (DM1) diagnosed in childhood with intensive insulin treatment from diagnosis.

METHODS

Eighty children and adolescents with DM1, age 7-22 years and DM1 duration >3 years, were studied. Neuropathy was defined as abnormal nerve conduction finding in > or = 2 of 4 nerves (sural and peroneal nerves), nephropathy as albumin excretion rate > or = 20 microg/min and retinopathy as all grades of retinal changes in fundus photographs.

RESULTS

The prevalence of neuropathy was 59%, of retinopathy 27% and of nephropathy 5% after 13 years DM1 duration. Mean (SD) long-term HbA1c was 8.4 (0.9)% (DCCT-corrected value).

CONCLUSION

Even in a population with intensive insulin treatment from the beginning and fairly good metabolic control, the prevalence of subclinical neuropathy was high, while other diabetic complications were lower than usually reported.

Rates of diabetes mellitus-related complications in a contemporary adolescent cohort

BACKGROUND

Ten years after the Diabetes Control and Complications Trial there is a paucity of data as to what are current rates of diabetes-related complications in adolescence.

OBJECTIVE

To assess the incidence of diabetes-related complications in a contemporary cohort of adolescents with type 1 diabetes mellitus.

DESIGN

Retrospective cross-sectional survey.

PATIENTS

Adolescents aged >10 years with type 1 diabetes mellitus for >5 years from the Royal Children's Hospital, Melbourne Diabetes Clinic.

RESULTS

382 patients were studied (191 male). The mean HbA1c for males was 8.72% and for females was 8.80%. The rates of hypothyroidism and hypercholesterolaemia were 1.5% and 22% respectively. Twenty-five patients (8%) had intermittent microalbuminuria and six (2%) had persistent microalbuminuria. Only one patient had macroalbuminuria (0.3%). Only two patients (0.7%) with mild non-were diagnosed proliferative diabetic retinopathy. Coeliac disease was diagnosed in 6% of patients.

CONCLUSIONS

In this representative and contemporary cohort of diabetic adolescents the incidence of microvascular diabetes-related complications is quite low.

Epidemiology of diabetic retinopathy and macular oedema: a systematic review

AIMS

To systematically review the literature on the prevalence and incidence of diabetic retinopathy (DR) and macular oedema (MO).

METHODS

A search of the bibliographic databases (Medline, Embase, CINAHL) was conducted up to October 2001. Selected relevant studies were scrutinized and included in the review.

RESULTS

A total of 359 studies were included. The studies were reported in nearly 100 different journals and in over 50 countries. The majority of the studies were US-based, with large studies such as the Wisconsin Epidemiologic Study of Diabetic Retinopathy dominating the literature. The studies were quite dated and highly heterogeneous in nature in terms of patient selection with variable inclusion criteria (age range, gender, diabetes duration and type, ethnicity, comorbidity, and DR status, assessment, and classification).

CONCLUSIONS

There are inconsistencies between epidemiological studies, and differences in study methods may contribute to conflicting reports of prevalence and incidence of DR and MO in diabetic populations. As new therapies for DR and its associated complications emerge, the need to capture and monitor new epidemiological data becomes increasingly important to be able to assess the impact and effectiveness of these therapies. Robust, longitudinal capture of patient data is, therefore, essential to evaluate the impact of current practice on the epidemiology of diabetic eye complications.

Funduscopic findings following cataract extraction by means of phacoemulsification in diabetic dogs: 52 cases (1993-2003)

OBJECTIVE

To determine prevalence of retinal hemorrhages and microaneurysms in dogs with diabetes mellitus following cataract extraction by means of phacoemulsification and identify potential risk factors.

DESIGN

Retrospective study.

PROCEDURE

Medical records of dogs undergoing phacoemulsification between 1993 and 2003 were reviewed, and information was recorded on signalment, history, physical examination findings, ophthalmic examination findings, results of laboratory testing, electroretinographic findings, and surgical findings. Glycemic control was classified as poor, intermediate, or good on the basis of baseline blood glucose concentration, perioperative body weight loss, daily insulin dosage, and presence of glucosuria and ketonuria. Data from diabetic and nondiabetic dogs were analyzed to determine prevalence and risk factors for development of retinal hemorrhages or microaneurysms following phacoemulsification.

RESULTS

11 of the 52 (21%) dogs with diabetes mellitus developed ophthalmoscopic signs of retinal hemorrhages or microaneurysms, compared with 1 of the 174 (0.6%) nondiabetic dogs. Median time from onset of diabetes mellitus to diagnosis of retinopathy was 1.4 years (range, 0.5 to 3.2 years). No risk factors for development of retinopathy were identified.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that retinal hemorrhages and microaneurysms may be more common and develop earlier in diabetic dogs than previously reported. This may affect treatment, as diabetic dogs survive longer with improved glycemic control.

Description of microangiopathy in children with type 1 diabetes mellitus: a 19-year retrospective study

BACKGROUND

The aim of the study was to estimate the outcome of patients with type 1 diabetes followed in a university hospital in the paediatric department and then in the adult diabetic department for at least 10 years.

METHODS

We made a retrospective analysis of 50 patients (28 women and 22 men) with type 1 diabetes with disease duration of 19 +/- 6 years and analysed whether retinopathy and nephropathy had progressed, had remained unchanged or had improved or normalised.

RESULTS

The mean age of diabetes onset was 8 +/- 4 years (1-16). Ketoacidosis revealed diabetes in 36% of the children. Mean HbA(1c) was 8.6 +/- 1.8%, and was over 8.5% in 34% of the patients. The mean age at onset of puberty (Tanner stage II) was 12 +/- 1 years in girls and 13 +/- 1 years in boys. Mean HbA(1c) was 7.9 +/- 1.2% during the year before onset of puberty and 8.7 +/- 1.1% in the following 3 years, corresponding to a 10% pubertal increase in HbA(1c). Retinopathy was seen in 50% of the patients at a mean age of 22 +/- 5 years, 15 +/- 6 years after onset of diabetes. Mean HbA(1c) was 9.7 +/- 1.6% in patients with proliferative retinopathy, 9.0 +/- 1.5% in patients with non proliferative retinopathy, and 8.1 +/- 1.3% in those without (p=0.02, proliferative versus no retinopathy, p > 0.05 non proliferative versus no retinopathy). Microalbuminuria was diagnosed in 26% of the patients. Mean HbA(1c) was 9.3 +/- 2.1% in patients with microalbuminuria versus 8.1 +/- 1.3% in those with normoalbuminuria (p=0.02).

CONCLUSIONS

Glycemic control was similar in patients with non proliferative retinopathy and those without. Proliferative retinopathy and nephropathy were both related to the level of glycemic control.

Do all prepubertal years of diabetes duration contribute equally to diabetes complications?

OBJECTIVE

This study was designed to explore the timeline of protection against complications in prepubertal children with diabetes, in particular the effects of diabetes duration before age 5 years.

RESEARCH DESIGN AND METHODS

In this study, 193 adolescents with prepubertal diabetes onset were followed longitudinally for retinopathy (early background and clinical) and microalbuminuria (albumin excretion rate >7.5 micro g/min and >20 micro g/min). Multiple logistic regression analysis was used to compare the effect of pre- and postpubertal diabetes duration on the risk of each complication in 90 subjects reassessed as young adults. For the entire cohort, Kaplan-Meier estimates were used to determine time free of each complication, and survival was compared in those diagnosed before and after age 5 years. Accelerated failure time modeling was used to estimate the effect of covariates, including diabetes duration before puberty, on the risk of complications.

RESULTS

Prepubertal duration improved the prediction for retinopathy over postpubertal duration alone in the young adults. The survival-free period of retinopathy and microalbuminuria was significantly longer (2-4 years) for those diagnosed before age 5 years compared with those diagnosed after age 5 years. Time to onset of all complications increased progressively with longer diabetes duration before gonadarche. Higher HbA(1c) during adolescence had an independent effect on the risk of retinopathy and microalbuminuria.

CONCLUSIONS

Prepubertal diabetes duration remains a significant predictor of retinopathy in young adults. The effect of time on the risk of retinopathy and microalbuminuria is nonuniform, with an increasing delay in the onset of complications in those with longer prepubertal duration. These findings are of major clinical importance when setting targets of glycemic control in young children who are at greatest risk of hypoglycemia.

Complications of pediatric and adolescent type 1 diabetes mellitus

Type 1 diabetes mellitus is potentially associated with serious microvascular and macrovascular complications, although these are usually subclinical during the pediatric and adolescent years. There is no "grace" period for the beginnings of such complications. Duration of diabetes, glycemic control, age, and pubertal stage are critical factors contributing toward development of such problems. Other risk factors include family history (genetic predisposition), hyperlipidemia, hypertension, and smoking. The Diabetes Control and Complications Trial (DCCT) proved the importance of glycemic control and emphasized the ability of improved glucose control to prevent or decrease retinopathy, nephropathy, and neuropathy using a multidisciplinary same-philosophy-of-care approach plus targeted glucose and hemoglobin A(1c) values. Other natural history and intervention studies support the findings of the DCCT. Although our current tools are not perfect, they allow us to decrease microangiopathic complications very significantly if we educate our patients and their family members. Metabolic control counts.

Intensive diabetes management in pediatric patients

Intensive diabetes management requires frequent home glucose monitoring, multiple daily insulin injections or chronic subcutaneous insulin infusion, and adjustments of insulin doses in response to changes in blood glucose levels, food intake, and exercise. It also requires a periodic review of previous glucose results to recognize patterns of hyper- or hypoglycemia. The goals of intensive management are age dependent. In young children, avoidance of severe hypoglycemia is the major goal. In older children and adolescents, lowering hemoglobin A(1c) becomes an increasingly important goal. In children of all ages, the ability to have a flexible lifestyle and meal plan is often a priority. This article provides a brief overview of the rationale for implementing intensive diabetes management in pediatric patients, and practical guidelines for implementation.

Diabetic retinopathy in childhood: long-term follow-up by fluorescein angiography beginning in the first months of disease

BACKGROUND

Little is known about minimal retinal lesions occurring in the first months of disease in children with type 1 diabetes mellitus (DM).

OBJECTIVE

To detect any early retinal change and to evaluate its progression in children diagnosed with type 1 DM.

PATIENTS

From 1979 to 1997 we examined by fluorescein angiography at diagnosis or within 15 months from the onset of DM 130 young patients with type 1 DM (mean age at diagnosis 10.08 +/- 2.62 yr). In 112 patients follow-up by fluorescein angiography was performed every 1.26 years with a mean of 5.41 fluorescein angiographies/patient.

METHODS

The stage of retinopathy was graded to detect minimal lesions. We also considered sex, pubertal stage, HLA, family history of DM, disease duration and HbA1c levels.

RESULTS

At first examination, 14 out of 127 (11%) readable angiographies showed minimal retinal changes. There was no statistically significant difference between the patients with or without lesions for all parameters considered. The 112 patients examined during follow-up were divided as follows: Group A: no retinopathy at first examination; Group A1: no retinopathy during follow-up; Group A2: retinal changes during follow-up; Group B: retinal changes at the first examination. Mean HbA1c value evaluated during the whole follow-up was lower in group A1 than in group A2. HbA1c levels at onset of the disease were significantly different in the three groups: in group A1 it was lower than in group A2 and in group B.

CONCLUSIONS

The presence of early lesions in the first year of disease in 11% of patients is probably due to the method of examination, which may detect even minimal retinal changes. This may be correlated to the acute metabolic failure present at the onset of disease. The prolonged follow-up seems to demonstrate that the early changes are not necessarily a negative prognostic factor in the evolution of diabetic retinopathy. We confirm that duration of DM and metabolic control are the main factors influencing the course of retinopathy in these young patients. Early fluorescein angiography is not particularly useful in the management of children with DM.

Abnormal markers of endothelial cell activation and oxidative stress in children, adolescents and young adults with type 1 diabetes with no clinical vascular disease

BACKGROUND

Endothelial cell dysfunction is an early feature of vascular disease and oxidative stress may be involved in its pathogenesis.

METHODS

Fifty-one children, adolescents and young people with Type 1 diabetes with no clinical diabetic angiopathy, mean age+/-SD of 16+/-4 years, diabetes duration of 8+/-5 years, and HbA(1c) of 8.5+/-1.6%, and 29 age, sex matched normal controls had blood samples assayed for E-selectin, intercellular cell adhesion molecule-1, von Willebrand Factor, red cell superoxide dismutase, plasma thiol and red cell glutathione.

RESULTS

E-selectin and ICAM-1 levels were significantly higher in the diabetic patients at 72+/-24 ng/ml and 287+/-57 ng/ml, respectively vs 43+/-16 ng/ml and 248+/-71 ng/ml in the normal controls (p<0.0002 and p<0.013). Von Willebrand Factor levels were not different between the two groups. Superoxide dismutase activity was significantly higher in the diabetic group at 220+/-58 micro/ml vs 175+/-24 micro/ml in the normal controls p<0.001, and those of plasma thiol and red cell glutathione were significantly lower in the diabetic group, at 1267+/-202 micromol/l and 458+/-38 micromol/l, respectively vs 1403+/-278 micromol/l and 487+/-70 micromol/l in the controls p<0.02 and p<0.03. Levels of superoxide dismutase correlated negatively with plasma thiol, age and diabetes duration r=-0.318, p<0.02; r=-0. 328, p<0.02; and r=-0.286, p<0.05, respectively.

CONCLUSION

These results confirm evidence of endothelial perturbation in young people with diabetes mellitus, and they also suggest that free radical generation may contribute to this dysfunction. This supports the hypothesis that vascular disease starts early in the course of childhood diabetes, akin to the situation in adults with diabetes.

Metabolic control and prevalence of microvascular complications in young Danish patients with Type 1 diabetes mellitus. Danish Study Group of Diabetes in Childhood

AIMS

After Danish nationwide investigations (1987, 1989) demonstrated unacceptable blood glucose control in unselected young diabetic patients, we set out to estimate the present glycaemic control and the prevalence of microvascular complications in a cohort of children and adolescents participating in the two previous studies.

METHODS

This follow-up represents 339 patients (47% of the inception cohort), median age 21.1 years (range 12.0-26.9), median diabetes duration 13.2 years (range 8.9-24.5). A standardized questionnaire, fundus photographs (with central reading) and a physical examination were performed. HbA1c and overnight albumin excretion rate (AER) were analysed centrally.

RESULTS

Although 88% (n= 309) of the young persons were treated with three or more daily insulin injections, HbA1c (nondiabetic range 4.3-5.8, mean 5.3%) was 9.7+/-1.7% (mean+/-SD). Males had higher HbA1c values than females (P < 0.015). Mean daily insulin dose was 0.92+/-0.25 IU.kg(-1).24h(-1). Microalbuminuria (AER > 20-150 microg/min) and macroalbuminuria (AER > 150 microg/min) were found in 9.0% and 3.7% of the patients, respectively, and was associated with increased diastolic blood pressure (P<0.01) and presence of retinopathy (P<0.01). Retinopathy was present in approximately 60% of the patients and was associated with age, diabetes duration, HbA1c, diastolic blood pressure and AER (all P<0.01). Subclinical neuropathy (vibration perception threshold by biothesiometry > 6.5 V) was found in 62% and showed a significant association with age, linear height, diastolic blood pressure (all P < 0.01) and diabetic retinopathy (P = 0.01).

CONCLUSIONS

In spite of the majority of the patients being on multiple insulin injections, only 11% had HbA1c values below 8% and the prevalence of diabetic microvascular complications in kidneys, eyes and nerves was unacceptable high.

Monitoring for retinopathy in children and adolescents with type 1 diabetes

In children with an average diabetes onset at 11 y of age, the first retinal changes can be expected after a median diabetes duration of 9 y, while the median time until clinically relevant background retinopathy is 14 y. Periodic examinations of the retinal status become necessary with the onset of puberty or after 5 y of diabetes duration. Only sensitive methods should be used for retinopathy screening; the minimum recommended standard is a stereoscopic slit-lamp biomicroscopic examination in mydriasis. The degree of glycaemic control, both before and after puberty, appears to be of outstanding importance for the development of retinopathy, but the contribution of other factors (arterial blood pressure, lipid abnormalities, sex steroids, smoking and genetic factors) may be of varying relevance in the individual patient. Thus, to improve the long-term prognosis for children with diabetes appropriate screening for retinopathy and associated risk factors is mandatory.

Diabetic retinopathy in pediatric patients with type-1 diabetes: effect of diabetes duration, prepubertal and pubertal onset of diabetes, and metabolic control

OBJECTIVE

The objective of this study was to determine the contribution of prepubertal and pubertal onset and duration of diabetes to the development of diabetic retinopathy.

STUDY DESIGN

A total of 1391 standardized fundus examinations (stereo fundus-photography) were performed in 441 children or adolescents with type-1 diabetes (median age 15.5 years, median duration of diabetes 6.3 years).

RESULTS

Mild nonproliferative retinopathy was present in 72 patients (median age 19.9 years). Life table analysis revealed a median duration of diabetes until retinopathy was first diagnosed at 16.6 years (95% confidence interval: 15.3 to 18.3). Patients were stratified according to diabetes onset before or in puberty (> or = 10.4 years in girls, > or = 12.2 years in boys). In children with a prepubertal onset of diabetes, retinopathy occurred after a pubertal duration of 10.9 years compared with 15.1 years in children with onset of diabetes in puberty (p < 0.01), demonstrating the additional risk conveyed by the prepubertal years of diabetes. Long-term metabolic control had a significant influence on the prevalence of retinopathy: patients with a median HbA1c > or = 7.5% had development of retinopathy on average after 15.5 years compared with 18.3 years in patients with lower HbA1c values (p < 0.05).

CONCLUSION

Both prepubertal and pubertal duration of diabetes are relevant for the development of background retinopathy. Good metabolic control should be attempted irrespective of age.

Development of vascular complications in diabetes

Chronic complications of diabetes are dominated by disorders of the vascular system. They are a much larger burden on both diabetic patients and overall medical costs than diabetes itself. Large vessel problems are far more frequent than microvascular disorders. Loss of arterial elasticity alters arterial flow patterns and increases microcirculatory peak flow rates. Hyperglycemia may directly disrupt elastin formation. Diabetic leg artery disease may be generated by nerve damage, reversing this interactive contribution sequence. The major anatomic feature of microangiopathy in long-term diabetes is an unevenly distributed thickening of the intima of smaller arterioles. The thickening is primarily due to accumulation of type IV (basement membrane) collagen. Arterioles change local vessel diameter to adjust blood distribution to meet current needs. The thickening compromises the maximum local blood flow that may be achieved by this means. Compromise of maximal arteriolar dilatation does not disrupt exercising muscle but in the kidney, retina, and possibly in nerve, local circumstances can generate serious damage. Each of these system's responses has unique features that mediate its vulnerability, but all these organs show arteriolar hyalinization. The increased arteriolar accumulation of type IV collagen appears to be a response to the tangential force generated by flow over local endothelial cells. An increase in peak arteriolar wall force is mediated by a diabetes-specific doubling of erythrocyte membrane curvature change resistance. Red cell aggregation rate determines the rate of damage. The same nonspecific burden may also predispose to heart disease and stroke. Intensive metabolic control improves red cell deformability and protects against arteriolar damage. Therapies that address the rheologic problem more directly may add to the effectiveness of good diabetes control in the future.

Lipid profiles and blood pressure: are they risk factors for the development of early background retinopathy and incipient nephropathy in children with insulin-dependent diabetes mellitus?

The objective of this study is to examine the influence of lipid profiles and blood pressure on the development of microvascular complications in adolescents with insulin-dependent diabetes mellitus (IDDM) in a matched pairs study. Patients with early background retinopathy (n = 21) or microalbuminuria (n = 15) and their respective statistical twins participated in the study. Serum total cholesterol, high-density lipoprotein (HDL) cholesterol, fasting triglycerides, glycosylated haemoglobin A1c (HbA1c), and systolic and diastolic blood pressure during 3 years prior to the development of early background retinopathy or incipient nephropathy were examined. The multivariate discriminant analysis demonstrated glycaemic control and HDL cholesterol to be the most important variables related to the development of retinal lesions (84% correctness), and diastolic blood pressure to be associated with microalbuminuria (57% correctness). In addition to poor glycaemic control, different factors seem to be important for the early retinal or renal lesions of juvenile IDDM.

Screening for diabetic retinopathy. Initiation and frequency

A screening program for diabetic eye disease was established in Iceland in 1980. Diabetics involved in the screening program have a low prevalence of blindness, 1% in type 1 and 1.6% in type 2. We examined ways to make the screening program more efficient by identifying subgroups at low risk of developing eye disease that require treatment and therefore need less frequent screening. We studied whether diabetic eye disease screening programs may be trimmed by excluding children and examining diabetics without retinopathy biannually. Our results indicate that diabetic children under the age of 12 years do not need regular screening for eye disease. Biannual examinations seem to suffice in type 1 and 2 diabetic patients without retinopathy. However, in a setting where the eye clinic is located apart from the diabetes clinics, biannual examinations present practical problems which could result in a less effective screening for diabetic eye disease.

Development and progression of diabetic retinopathy: adolescents at risk

The aims of this study were to evaluate short-term changes in retinopathy in adolescents, and to examine the relationship of these changes to risk factors. Two-hundred and three adolescents, with a median age of 14.5 (range 10.4 to 20.6) yr and a median duration of diabetes of 6.6 (1.1 to 16.3) yr, were included in the study. Retinopathy was assessed on two occasions, using stereoscopic fundus photography; the median time between assessment was 1.3 (0.5 to 3.0) yr. At baseline, 41% of the adolescents had background retinopathy. When patients were stratified according to the median diabetes duration (DD) (6.6 yr) and glycaemic control over the 12 months prior to assessment (HbA1C) (8.4%), the percentage of retinopathy in each group was: lowDD/lowHbA1C 13%; lowDD/highHbA1C 40%; highDD/lowHbA1C 42%; and highDD/highHbA1C 72%. Using a 2-step criteria for stability or change in retinopathy, 11% of the 203 adolescents showed progression of retinopathy, 41% had stable retinopathy, 5% showed regression, and 43% had no retinopathy at either assessment. Change in retinopathy was related to age at baseline assessment (borderline significance, p = 0.06), diabetes duration (p < 0.001), glycaemic control (p < 0.001) and total cholesterol (p = 0.04), and was also related to DD/HbA1C group membership (chi 2, p < 0.001). This study highlights the combined adverse effect of long diabetes duration and poor glycaemic control on the development and progression of retinopathy during adolescence, and identifies a group that is likely to show progression over a relatively short period.

Determinants of blood glucose variability in adolescents with insulin-dependent diabetes mellitus

Metabolic control and blood glucose variability in children with insulin-dependent diabetes mellitus (IDDM) during and after puberty were studied. Seventy-two children (43M, 29F), aged 10-19 years, with a 2-16-year duration of IDDM participated in the study. Fourteen of the patients were prepubertal (Tanner stage 1), 27 pubertal (Tanner 2-4) and 31 postpubertal (Tanner 5). They performed self-monitoring of blood glucose (SMBG) five times daily, every 2 days for 4 weeks. The SD (SDbg) for all values in each patient was calculated as a measure of blood glucose variability. Weight-length index, linear growth velocity and Tanner stage were recorded. Hemoglobin (Hb)A1c, alkaline phosphatase and sex hormone levels in serum were analyzed. Subjectively experienced hypoglycemic episodes were recorded. HbA1c levels showed no relation to Tanner stage. SDbg was lower in stage 5 than in stages 2-4 (p = 0.02). There was no significant correlation between HbA1c and SDbg, but the variability was significantly lower in individuals with mean blood glucose in the lower quartile compared with those in the upper three quartiles (p < 0.001). Alkaline phosphatase concentration, as a measure of growth velocity, was the main independent determinant of SDbg (r = 0.35, p < 0.005). There was an inverse correlation between levels of sex hormones and SDbg. We conclude that blood glucose variability is lower after than during puberty. This variability seems to be related to linear growth velocity or its biochemical marker.

Refraction and retinopathy in diabetic children below 16 years of age

In a population-based cross-sectional study of insulin-dependent diabetes mellitus, 42 children--with a median age of 11 years (range 7-15 years) and a median duration of diabetes of 4 years (range 1-12 years)--underwent an ophthalmological and a biochemical examination (HbA1c). None of the children had visual loss due to diabetes, and only 4.8% had mild, non-proliferative retinopathy. Using cycloplegic refractioning, we found low degree myopia (less than -2D) in 12% of the patients, whereas non-mydriatic measurements increased the frequency of myopia to 29%. We therefore recommend the use of cycloplegia in refractive evaluations of diabetic children.

The direct cost of type 1 diabetes mellitus in Israel

Estimates of the cost of Type 1 (insulin-dependent) diabetes mellitus should take into account the development of various complications. In this study, we calculated separately the basic direct costs of a Type 1 diabetic patient over a span of 35 years of living with the disease, and on average, the cost of complications which developed during this period of time. Assessment of costs showed that there is a difference between the cost of treating the disease itself, which decreases over the years, and the cost of treating its complications, which increases. The cost of treating one patient over the 35-year period amounted to about 247,000 pounds in 1993 prices, and in terms of discount value, to about 104,000 pounds. These costs are significant in planning the health expenditure and the investment of resources for prevention of the disease, and in selecting proper methods of treatment of complications.

Prevalence and risk factors for retinopathy in adolescents with type 1 diabetes

OBJECTIVES

To establish the prevalence of, and risk factors associated with, diabetic retinopathy in an Australian adolescent diabetes clinic population.

DESIGN

A prospective longitudinal study; baseline findings.

PATIENTS

Two hundred and fifty-five patients with Type 1 (insulin-dependent) diabetes mellitus assessed by our service were studied. Entry criteria were: age 11.0-19.9 years; diabetes duration of at least two years; and gradable fundus photographs of at least one eye.

MAIN OUTCOME MEASURES

The presence and severity of retinopathy, as assessed by the grading of stereoscopic fundus photographs. Possible risk factors assessed were age, sex, diabetes duration, pubertal stage, blood pressure, glycaemic control and total cholesterol level.

RESULTS

The prevalence of retinopathy was 42%; all of those affected had mild background retinopathy. Highly significant associations were found with glycaemic control and both total and prepubertal duration of diabetes. No associations were found with age, sex, pubertal stage, blood pressure or total cholesterol level.

CONCLUSIONS

The high prevalence of early diabetic retinopathy in this group of Australian adolescents is comparable to recent reports from other centres. The significant associations with glycaemic control and duration of diabetes provide further strong evidence for the benefit of optimal glycaemic control during adolescence. Our finding that the prepubertal years of diabetes contribute to the development of retinopathy suggests that glycaemic control before puberty should also be optimised. The planned follow-up of this cohort will establish the risk of progression to vision-threatening retinopathy and allow risk factors to be further evaluated.

Persistent microalbuminuria in adolescents with type I (insulin-dependent) diabetes mellitus is associated to early rather than late puberty. Results of a prospective longitudinal study

Microalbuminuria is generally accepted to be highly predictive of overt diabetic nephropathy which is the leading cause of end-stage renal failure and, consequently, of death in patients with type 1 (insulin-dependent) diabetes mellitus (IDDM). Its early identification and therapy are exceedingly important. We studied prospectively the occurrence of microalbuminuria (MA) in relation to puberty and its pubertal stages in 164 children and adolescent patients (83 girls and 81 boys) with IDDM. Analysing 100 healthy subjects, normal values for albumin excretion (range: 0-10.1 micrograms/min/1.73 m2) according to sex and the different pubertal stages were defined. No significant difference between the groups were noted and, therefore, 20 micrograms/min per 1.73 m2 (3 SD above the mean) was generally defined as cutoff for MA. Of the patients with IDDM studied, 20% (20 females and 12 males) developed persistent MA (22.1-448.2 micrograms/min/1.73 m2) during the study period of 8 years. The first manifestation of persistent MA was in 69% (13 females and 9 males) during stages of early and midpuberty; and in 28% (6 females and 3 males) at a late pubertal stage or at the end of puberty. The only child who developed MA before the onset of puberty (range: 23.5-157.4 micrograms/min/1.73 m2) was found to have dystopic kidney. Therefore, all patients with IDDM should be screened for MA regardless of diabetes duration, sex and level of diabetes control beginning at the very first stage of puberty and neither earlier nor after puberty as suggested by the American Diabetes Association.