Population-based survey and analysis of trends in the prevalence of diabetic nephropathy in Type 1 diabetes

Prevalence of albuminuria and renal dysfunction, and related clinical factors in Japanese patients with diabetes: The Japan Diabetes Complication and its Prevention prospective study 5

AIMS/INTRODUCTION

To clarify the prevalence of albuminuria and renal dysfunction, and related factors in Japanese patients with diabetes, we analyzed the baseline data of the Japan Diabetes Complication and its Prevention prospective study.

MATERIALS AND METHODS

We used the data of 355 patients with type 1 diabetes and 5,194 patients with type 2 diabetes to evaluate the prevalence of albuminuria and renal dysfunction, and related factors. A binomial logistic regression analysis was used to investigate independent contributing factors for estimated glomerular filtration rate <60 mL/min/1.73 m2 or albuminuria.

RESULTS

The prevalence of microalbuminuria and macroalbuminuria was 15.2% (54/355) and 3.1% (11/355) in type 1 diabetes patients, and 25.0% (1,298/5,194) and 5.1% (265/5,194) in type 2 diabetes patients, respectively. The proportion of renal dysfunction (estimated glomerular filtration rate <60 mL/min/1.73 m2 ) was 9.9% (35/355) in type 1 diabetes patients, and 15.3% (797/5,194) in type 2 diabetes patients. The proportion of patients with renal dysfunction with normoalbuminuria was 7.3% (26/355) for type 1 diabetes patients, and 9.0% (467/5,194) for type 2 diabetes patients. The factors related to albuminuria in type 2 diabetes patients were glycated hemoglobin, hypertension, age, duration of diabetes, body mass index and estimated glomerular filtration rate. In contrast, factors to related renal dysfunction were age, duration of diabetes, dyslipidemia, hypertension, body mass index, male sex and albuminuria.

CONCLUSIONS

We showed the recent prevalence of albuminuria and renal dysfunction, and related factors in Japanese type 1 and type 2 diabetes patients using the baseline data of the Japan Diabetes Complication and its Prevention prospective study. The current results suggest that renal disease in patients with type 2 diabetes is heterogeneous, and different mechanisms might be involved in albuminuria and deterioration of renal function.

Risk of renal disease in patients with both type 1 diabetes and coeliac disease

AIMS/HYPOTHESIS

Our aim was to study the risk of renal disease in patients with type 1 diabetes (T1D) and coexisting coeliac disease (CD).

METHODS

Individuals with T1D were defined as having a diagnosis of diabetes recorded at ≤30 years of age in the Swedish Patient Register between 1964 and 2009. Individuals with CD were identified through biopsy reports with villous atrophy (Marsh stage 3) from 28 pathology departments in Sweden between 1969 and 2008. We identified 954 patients with both T1D and CD. For each patient with T1D + CD, we selected five age- and sex-matched reference individuals with T1D only (n = 4,579). Cox regression was used to estimate the following risks: (1) chronic renal disease and (2) end-stage renal disease in patients with CD + T1D compared with T1D patients only.

RESULTS

Forty-one (4.3%) patients with CD + T1D and 143 (3.1%) patients with T1D only developed chronic renal disease. This corresponded to an HR of 1.43 for chronic renal disease (95% CI 0.94, 2.17) in patients with CD + T1D compared with T1D only. In addition, for end-stage renal disease there was a positive (albeit statistically non-significant) HR of 2.54 (95% CI 0.45, 14.2). For chronic renal disease, the excess risk was more pronounced after >10 years of CD (HR 2.03, 95% CI 1.08, 3.79). Risk estimates were similar when we restricted our cohort to the following T1D patients: (1) those who had an inpatient diagnosis of T1D; (2) those who had never received oral glucose-lowering medication; and (3) those who had not received their first diabetes diagnosis during pregnancy.

CONCLUSIONS/INTERPRETATION

Overall this study found no excess risk of chronic renal disease in patients with T1D and CD. However, in a subanalysis we noted a positive association between longstanding CD and chronic renal disease in T1D.

Epidemiology of diabetic kidney disease

The increasing prevalence of diabetes has led to DKD becoming the leading cause of ESRD in many regions. The economic cost of DKD will grow to prohibitive amounts unless strategies to prevent its onset or progression are urgently implemented. In type 1 and type 2 diabetes, the presence of microalbuminuria and macroalbuminuria confers increased risk of developing ESRD and of death. Comparison of recent studies with earlier historical studies shows that the incidence of ESRD and death has decreased in DKD. Increased risk of albuminuria has been identified in certain non-European ethnic groups. However, the initial concept of progression of DKD as an albuminuric phenotype involving development of microalbuminuria, macroalbuminuria, and then ESRD has had to be modified. Albumin excretion frequently regresses, and GFR can decline without abnormality in albumin excretion. There is emerging evidence that changes in renal function occurring early in the course of diabetes predict future outcomes. The major challenges are to prevent DKD onset, to detect it early, and to improve DKD outcomes globally.

Identifying additional patients with diabetic nephropathy using the UK primary care initiative

AIMS

The aim of this study was to use general practice data to estimate the prevalence of diabetic nephropathy within the registered diabetes patients and examine variation in practice prevalence and management performance since introduction of this initiative.

METHODS

Reported quality indicators from the Northern Ireland General Practice Quality and Outcomes Framework were analysed for diabetes and diabetic nephropathy prevalence and management in the period 2004-2008. Variation in prevalence at practice level was assessed using multiple linear regression adjusting for age, practice size, deprivation and glycaemic control.

RESULTS

In 2006-2007, 57,454 (4.1%) adult diabetic patients were registered in the denominator population of 1.4 million compared with 51,923 (3.8%) in 2004-2005 (mean practice range 0.5-7.7%). Diabetic nephropathy prevalence was 15.1 and 11.5%, respectively (8688 and 5955 patients). Documented diabetic nephropathy prevalence showed marked variation across practices (range 0-100%) and was significantly negatively correlated with diabetes list size, albumin creatinine ratio testing rates and renin-angiotensin-aldosterone system blockade use and positively correlated with exception reporting rates. Specifically, for every increase in 100 diabetic patients to a register, documented diabetic nephropathy prevalence reduced by 40% (P=0.003). On the positive side, median albumin-creatinine ratio testing rates doubled to 82% compared with figures in the pre-Framework era.

CONCLUSIONS

Implementation of the Northern Ireland General Practice Quality and Outcomes Framework has positively benefitted testing for diabetic nephropathy and increased numbers of detected patients in a short space of time. Large variation in diabetic nephropathy prevalence remains and is associated with diabetes registry size, screening and treatment practices, suggesting that understanding this variation may help detect and better manage diabetic nephropathy.

Cost-effectiveness of insulin detemir compared with neutral protamine Hagedorn insulin in patients with type 1 diabetes using a basal-bolus regimen in five European countries

OBJECTIVES

The aim of this analysis was to evaluate the long-term clinical and economic outcomes associated with insulin detemir and neutral protamine Hagedorn (NPH) insulin in combination with mealtime insulin aspart in patients with type 1 diabetes in Belgian, French, German, Italian and Spanish settings.

METHODS

The published and validated IMS CORE Diabetes Model was used to make long-term projections of life expectancy, quality-adjusted life expectancy and direct medical costs. The analysis was based on patient characteristics and treatment effects from a 2-year randomised controlled trial. Events were projected for a time horizon of 50 years. Potential uncertainty using a modelling approach was addressed.

RESULTS

Basal-bolus therapy with insulin detemir was projected to improve quality-adjusted life expectancy by 0.45 years versus NPH in the German setting, with similar improvements in the other countries. Insulin detemir was associated with cost savings in Belgium, Germany and Spain. In France and Italy, lifetime costs were slightly higher in the detemir arm, leading to incremental cost-effectiveness ratios of 519 euro per QALY gained and 3,256 euro per QALY gained, respectively.

CONCLUSIONS

Compared to NPH, insulin detemir is likely to be a dominant treatment strategy in Belgium, Germany and Spain and highly cost-effective in France and Italy in patients with type 1 diabetes.

Diabetic nephropathy in children and adolescents

Type 1 diabetes mellitus (T1DM) commonly occurs in childhood or adolescence, although the rising prevalence of type 2 diabetes mellitus (T2DM) in these age groups is now being seen worldwide. Diabetic nephropathy (DN) develops in 15-20% of subjects with T1DM and in similar or higher percentage of T2DM patients, causing increased morbidity and premature mortality. Although overt DN or kidney failure caused by either type of diabetes are very uncommon during childhood or adolescence, diabetic kidney disease in susceptible patients almost certainly begins soon after disease onset and may accelerate during adolescence, leading to microalbuminuria or incipient DN. Therefore, all diabetics warrant ongoing assessment of kidney function and screening for the earliest manifestations of renal injury. Pediatric health care professionals ought to understand about risk factors, strategy for prevention, method for screening, and treatment of early DN. This review considers each form of diabetes separately, including natural history, risk factors for development, screening for early manifestations, and strategy recommended for prevention and treatment of DN in children and adolescents.

Familial risk factors for microvascular complications and differential male-female risk in a large cohort of American families with type 1 diabetes

CONTEXT

Type 1 diabetes (T1D) complications are responsible for much of the disease morbidity. Evidence suggests that familial factors exert an influence on susceptibility to complications.

OBJECTIVES

We investigated familial risk factors and gender differences for retinopathy, nephropathy, and neuropathy.

DESIGN AND SETTING

This study was a case-control design nested on a cohort of T1D families. We collected data (questionnaire, medical records) starting in 1988. Follow-up has been ongoing since 2004.

PATIENTS

There were 8114 T1D patients among 6707 families. All patients had T1D onset age younger than 30 yr and required insulin treatment. Patients who remained without a complication after more than 15 yr of diabetes were considered to be without that complication for our analyses.

RESULTS

A complication in a sibling increased the risk for that complication among probands: odds ratio 9.9 (P < 0.001) for retinopathy, 6.2 for nephropathy (P < 0.001), and 2.2 for neuropathy (P < 0.05). Compared with male probands, a female T1D proband had 1.7-fold higher retinopathy risk (P < 0.001) and 2-fold higher neuropathy risk (P < 0.001). T1D cases with onset between ages 5 and 14 yr had an increased complications risk compared with subjects diagnosed either at a very young age or after puberty. The presence of one complication significantly increased the risk for others. If a parent had type 2 diabetes, the risk for nephropathy increased (odds ratio 1.9, P < 0.01, but T1D in a parent did not increase the risk).

CONCLUSIONS

We confirmed that familial factors influence T1D microvascular pathologies, suggesting a shared genetic basis for complications, perhaps independent of T1D susceptibility. We also found an unexpected increased female risk for complications.

Trends in incidence of treated end-stage renal disease, overall and by primary renal disease, in persons aged 20?64�years in Europe, Canada and the Asia-Pacific region, 1998?2002

AIMS

To determine if rates of diabetic and non-diabetic end-stage renal disease (ESRD), which had been rising in young and middle-aged adults in all populations up to the mid-1990s, had started to decline, and if so, whether improvement had occurred in respect of each of the principal primary renal diseases causing ESRD.

METHODS

Poisson regression of age- and sex-standardized incidence of ESRD for persons aged 20-64 years in 18 populations from Europe, Canada and the Asia-Pacific region, for 1998-2002.

RESULTS

In persons from 12 European descent (Europid) populations combined, there was a small downward trend in all-cause ESRD (-1.7% per year, P = 0.001), with type 1 diabetic ESRD falling by 7.8% per year (P < 0.001), glomerulonephritic ESRD by 3.1% per year (P = 0.001), and 'all other non-diabetic' ESRD by 2.5% per year (P = 0.02). The reductions in ESRD attributed to hypertensive (-2.2% per year) and polycystic renal disease (-1.5% per year) and unknown diagnosis (-0.2% per year) were not statistically significant. On the other hand, the incidence of type 2 diabetic ESRD rose by 9.9% per year (P < 0.001) in the combined Europid population, although that of (principally type 2) diabetic ESRD remained unchanged in the pooled data from the four non-Europid populations.

CONCLUSION

Recent preventive strategies, probably chiefly modern renoprotective treatment, appear to have been effective for tertiary prevention of ESRD caused by the proteinuric nephropathies other than type 2 diabetic nephropathy, for which the continuing increase in Europid populations represents a failure of prevention and/or a change in the nephropathic potential of type 2 diabetes.

Divergent trends in the incidence of end-stage renal disease due to Type 1 and Type 2 diabetes in Europe, Canada and Australia during 1998-2002

AIMS

To describe the variation in geographical distribution of end-stage renal disease (ESRD) due to Type 1 and Type 2 diabetes, and to calculate recent trends in incidence in predominantly white populations.

METHODS

Estimation of age- and sex-standardized incidence of ESRD by type of diabetes, and temporal trends, in population-based data for persons aged 30-44, 45-54 or 55-64 years newly treated for ESRD during 1998-2002 in eight countries or regions of Europe, and Non-Indigenous Canadians and Australians.

RESULTS

The incidence of ESRD due to Type 1 diabetes at age 30-44 years correlated with published rates of childhood-onset insulin dependent diabetes mellitus (P = 0.0025). ESRD due to Type 2 diabetes was uncommon before 45 years of age; in older persons, the highest rates (in Canada and Austria) were five times the lowest rates (in Norway and the Basque region). Rates of ESRD due to Type 1 diabetes fell, per year, by 6.4%[95% confidence interval (CI): 2.1-10.6%) in persons aged 30-44 years, and by 7.7% (95% CI: 2.4-12.7%] in those aged 45-54 years. In contrast, rates of ESRD due to Type 2 diabetes increased annually by 16% (95% CI: 5-28%) in the 30-44-year age group, 11% (95% CI: 6-16%) at 45-54 years, and 9% (95% CI: 5-14%) at 55-64 years.

CONCLUSIONS

Modern prevention has reduced progression of nephropathy to ESRD due to Type 1 diabetes, but the continuing rise of ESRD due to Type 2 diabetes represents a failure of current disease control measures that has serious public health implications.

Prevalence of retinopathy and microalbuminuria in pediatric type 2 diabetes mellitus

BACKGROUND

There has been a dramatic rise of type 2 diabetes mellitus (DM2) in the US pediatric population, yet the presence of retinopathy and microalbuminuria in this cohort has not yet been described.

AIM

To assess the presence of retinopathy and microalbuminuria in a cohort of predominantly minority adolescents (African American and Caribbean Hispanic) with DM2.

PATIENTS AND METHODS

Forty pediatric patients with DM2 were examined between July, 2001 and June, 2003 for the presence of retinopathy. Data were also collected regarding microalbuminuria, body mass index, HbA1c, and family history of DM.

RESULTS

Of the 40 patients examined, one patient (2.5%) had retinopathy, whereas nine (27.3%) had microalbuminuria.

CONCLUSIONS

In young predominantly minority adolescents with DM2, retinopathy is rare, while microalbuminuria is common.

The course of diabetic glomerulopathy in patients with type I diabetes: a 6-year follow-up with serial biopsies

Diabetic nephropathy is a severe complication and few studies have described the early morphological changes over time. Two kidney biopsies were performed, within a 6-year interval, in 29 primarily normoalbuminuric patients, aged 24 years at the second biopsy. These were examined with light and electron microscopy. Glomerular filtration rate, and effective renal plasma flow were determined with inulin and para-aminohippurate clearances. Urinary albumin excretion rate and the 24 ambulatory blood pressure were determined. Ten patients had developed microalbuminuria and/or hypertension; of these, six were treated with antihypertensive medication for 2 years or more. Significant increases were found in night time diastolic blood pressure and decreases in systolic and diastolic dipping. The glomerular volume, mesangial volume, mesangial matrix volume fraction and foot process width increased significantly. The group that was treated later for complications had the worst long-term metabolic control, thicker basement membranes and larger mesangial matrix and volume at the first biopsy, than the persistent normoalbuminuric group. During the follow-up, the untreated group with complications and the persistent normoalbuminuric group showed an increase in morphological parameters, whereas no progression occurred in the treated patients who also improved their metabolic control. In conclusion, the morphological parameters deteriorated in the normoalbuminuric patients and in those with complications, but were unchanged in the small antihypertensive-treated group with improved metabolic control.

Recent advances in diabetic nephropathy

Diabetic nephropathy is the leading cause of end stage renal disease worldwide and is associated with increased cardiovascular risk. The earliest clinical manifestation is of microalbuminuria. Tight blood glucose and blood pressure control reduce the risk of microalbuminuria. Once microalbuminuria is present, the rate of progression to end stage renal disease and of cardiovascular disease can be delayed by aggressive management of blood pressure, glucose, and lipids. Inhibition of the renin-angiotensin system is important to reduce intraglomerular pressure but other classes of antihypertensive agent may also be needed to gain adequate control of systemic blood pressure. Such measures can at least half the rate of progression of nephropathy and cardiovascular disease.

Microalbuminuria and risk factors in type 1 and type 2 diabetic patients

A prospective study of normoalbuminuric diabetic patients was performed between 1997 and 2002 on 4097 type 1 and 6513 type 2 diabetic patients from the Swedish National Diabetes Register (NDR); mean study period, 4.6 years. The strongest independent baseline risk factors for the development of microalbuminuria (20-200 microg/min) were elevated HbA(1c) and diabetes duration in both types 1 and 2 diabetic patients. Other risk factors were high BMI, elevated systolic and diastolic BP in type 2 patients, and antihypertensive therapy in type 1 patients. A subsequent larger cross-sectional study in 2002 showed that established microalbuminuria was independently associated with HbA(1c), diabetes duration, systolic BP, BMI, smoking and triglycerides in types 1 and 2 diabetic patients, and also with HDL-cholesterol in type 2 patients. Relatively few types 1 and 2 patients with microalbuminuria achieved treatment targets of HbA(1c) < 6.5% (21-48%), BP < 130/85 mmHg (33-13%), cholesterol < 5 mmol/l (48-46%), triglycerides < 1.7 mmol/l (83-48%) and BMI < 25 kg/m(2) (50-18%), respectively. In conclusion, high HbA(1c), BP and BMI were independent risk factors for the development of microalbuminuria in types 1 and 2 diabetic patients. These risk factors as well as triglycerides, HDL-cholesterol and smoking were independently associated with established microalbuminuria. Treatment targets were achieved by a relatively few patients with microalbuminuria.

Unchanged incidence of diabetic nephropathy in Type 1 diabetes: a nation-wide study in Iceland

AIMS

Diabetic nephropathy is an uncommon cause of end-stage renal disease in Iceland in contrast to most industrialized countries. The aim of this study was to examine the incidence of diabetic nephropathy in Iceland.

METHODS

All patients diagnosed with Type 1 diabetes in Iceland before 1992 were studied retrospectively. Patients diagnosed before age 30, who were insulin dependent from the onset, were defined as having Type 1 diabetes. Diabetic nephropathy was defined as persistent proteinuria measured with a dipstick test (Albustix) on three consecutive clinic visits at least 2 months apart. Patients were followed to the end of year 1998, to their last recorded outpatient visit, or until death. The cumulative incidence of diabetic nephropathy was calculated with the Kaplan-Meier method and presented according to the duration of diabetes divided into 5-year intervals.

RESULTS

A total of 343 patients with Type 1 diabetes were identified. The mean follow-up period was 20.2 +/- 11.4 (mean +/- sd) years. Only 9.3% of patients were lost to follow-up. Sixty-five patients developed diabetic nephropathy. The cumulative incidence was 22.6% at 20 years and levelled off at 40.3% after approximately 35 years of diabetes duration. No significant changes in cumulative incidence were observed over time. Mean glycated haemoglobin was 8.4% in patients with proteinuria and 7.8% in a group of patients without proteinuria that was matched for age, gender and duration of diabetes (P = 0.04).

CONCLUSIONS

The cumulative incidence of diabetic nephropathy in Iceland is comparable with previously reported cumulative incidence rates and has remained unchanged. Glycaemic control was significantly better in patients without proteinuria.

Orosomucoid in urine is a powerful predictor of cardiovascular mortality in normoalbuminuric patients with type 2 diabetes at five years of follow-up

AIMS/HYPOTHESIS

To study whether urinary orosomucoid excretion rate (UOER) predicts mortality in normoalbuminuric patients with diabetes at 5 years of follow-up, and to investigate the relationship between orosomucoid in serum and urine.

METHODS

A cohort of 578 patients with diabetes (430 type 2, 148 type 1) was followed prospectively for an average of 5 years. UOER was measured in timed overnight urine samples.

RESULTS

Eighty-two patients with type 2 diabetes and 17 patients with type 1 diabetes died. Among patients with type 2 diabetes, 251 (58%) had normoalbuminuria; increased UOER independently predicted cardiovascular mortality (OR 4.94, 95% CI 1.60-15.22; p<0.006) in those with normoalbuminuria and in the entire cohort of patients with type 2 diabetes (odds ratio 3.63, 95% CI 1.50-8.81; p<0.005). Patients with increased UOER had a higher all-cause mortality than those with normal UOER (log-rank test, p<0.001 for type 2 patients; p<0.04 for type 1 patients). In patients with type 1 diabetes, there were five cardiovascular deaths and no significant predictive value of UOER. Patients with increased UOER had a subclinical increase in serum orosomucoid.

CONCLUSION/INTERPRETATION

Increased UOER was an independent, powerful predictor of cardiovascular mortality in normoalbuminuric patients with type 2 diabetes and in the entire cohort of patients with type 2 diabetes. There were indications of UOER as being a valuable marker in type 1 diabetes that showed differences in survival between patients with normal versus increased UOER. Serum orosomucoid was associated with UOER; UOER may be a marker of low-grade inflammation in patients with diabetes.

Cost-effectiveness of detemir-based basal/bolus therapy versus NPH-based basal/bolus therapy for type 1 diabetes in a UK setting: an economic analysis based on meta-analysis results of four clinical trials

BACKGROUND

A meta-analysis of results from four clinical trials in type 1 diabetes patients showed that insulin detemir (IDet)-based basal/bolus treatment of type 1 diabetes led to improved HbA1c (0.15%-points lower), reduced risk of major hypoglycaemic events (by 2%) and reduction in body mass index (BMI) (0.26 kg/m2) compared to protamine Hagedorn human (NPH) insulin-based basal/bolus therapy in type 1 patients.

METHODS

A published, validated, peer-reviewed Markov simulation model (the CORE Diabetes Model) projected short-term results obtained from the fixed-effects (weighted average) meta-analysis to long-term incidence of complications, improvements in quality-adjusted life years (QALY), long-term costs and the cost-effectiveness for IDet combinations versus NPH combinations in type 1 diabetes patients. Probabilities of complications and HbA1c-dependent adjustments were derived from the DCCT and other studies. Costs of treating complications in the UK were retrieved from published sources. Total direct costs (complications + treatment costs) for each arm were projected over patient lifetimes from a UK National Heath Service perspective. Both costs and clinical outcomes were discounted at 3.5% annually.

RESULTS

Improved glycaemic control, decreased hypoglycaemic events and BMI with IDet-based basal/bolus therapy led to fewer diabetes-related complications, an increase in quality-adjusted life expectancy of 0.09 years, increased total lifetime costs/patient of 1707 pounds sterling and an incremental cost-effectiveness ratio of 19,285 pounds sterling per QALY gained. Results were stable under a wide range of reasonable assumptions.

CONCLUSIONS

Short-term improvements seen with IDet combinations versus NPH combinations led to decreased complications, improvements in QALYs and reductions in complication costs, which partially offset the additional costs of detemir, leading to a cost-effectiveness ratio which fell within a range considered to represent excellent value for money (< 35,000 pounds sterling/QALY gained).

Declining incidence of severe retinopathy and persisting decrease of nephropathy in an unselected population of Type 1 diabetes-the Linköping Diabetes Complications Study

AIMS/HYPOTHESIS

In a previous study conducted over the last decades we found a decreased incidence of nephropathy but unchanged incidence of severe retinopathy among patients with Type 1 diabetes diagnosed in childhood and with 20 years duration of diabetes. The aim of our current study was to investigate the incidence 5 to 10 years later in the same population.

METHODS

We studied all 269 patients in whom Type 1 diabetes was diagnosed in childhood between 1961 and 1985 in a district in southeastern Sweden. Ninety-one percent were monitored for retinopathy until at least 1997 and 95% were monitored for nephropathy. Severe retinopathy was defined as laser-treated retinopathy and nephropathy as persistent proteinuria. Survival analysis was used and the patients divided into five cohorts according to the time of onset of diabetes.

RESULTS

The cumulative proportion of severe retinopathy had declined ( p=0.006). After 25 years it was 47% (95% CI 34-61), 28% (15-40) and 24% (12-36) in the cohorts 1961 to 1965, 1966 to 1970 and 1971 to 1975 respectively. After 30 years it was 53% (40-66) and 44% (28-59) in the oldest cohorts. The cumulative proportion of nephropathy after 25 years duration was 30% (18-42), 8% (1-16) and 13% (4-23) in the cohorts 1961 to 1965, 1966 to 1970 and 1971 to 1975 respectively. After 30 years, it was 32% (20-44) and 11% (2-20) for the oldest cohorts ( p<0.0001).

CONCLUSIONS/INTERPRETATION

In an unselected population with Type 1 diabetes diagnosed in childhood, modern diabetes care markedly reduced the incidence of severe retinopathy and nephropathy.

The long-term renal and retinal outcome of childhood-onset Type 1 diabetes

AIMS

To quantify the influence of childhood onset on long-term renal and retinal outcome in Type 1 diabetes.

METHODS

We used a population-based diabetes register to identify all Type 1 patients diagnosed before age 15 from 1960 to 1982 and resident in a defined catchment area in 1999. Those diagnosed before age 5, aged 5-9 and 10-14 years were compared with a reference group diagnosed at age 21-25 years over the same period.

RESULTS

Compared with adult-onset controls, proteinuria occurred earlier (P = 0.02) and nephropathy outcome was worse (P = 0.008) in childhood-onset diabetes. The risk of developing microalbuminuria was greater in childhood-onset diabetes: odds ratio 2.6 (95% confidence interval 1.4-4.9, P = 0.003). The relative risk of established nephropathy was 3.8 (1.5-9.4, P = 0.005) with childhood onset. The number developing background retinopathy did not differ with age at onset but younger onset patients were more likely to need laser treatment: relative risk 2.1 (1.1-3.8, P = 0.02). This maintained visual outcome which was not significantly different between the various age at onset groups.

CONCLUSIONS

Patients with onset of Type 1 diabetes before age 15 have substantially worse renal outcome and require more laser treatment than adult-onset patients. Differences between those with onset before age 5, onset at 5-9 and 10-14 years are small compared with the difference between childhood onset and adult onset. Events in the teenage years therefore appear to have a major adverse effect on the risk of developing long-term microvascular complications.

The health care costs of diabetic nephropathy in the United States and the United Kingdom

PROBLEM

Diabetic nephropathy (DN) is a common microvascular complication of diabetes and can result in end-stage renal disease (ESRD) necessitating long-term dialysis or kidney transplantation. The costs of these complications are relatively high. The aim of this study was to quantify and compare the rates and annual costs of DN in the USA and the UK.

METHODS

A cost of illness model was used to estimate the numbers of people with DN (microalbuminuria, overt nephropathy, and ESRD) or a previous kidney transplant at a given point in time and the numbers of new kidney transplants during a year. All costs were estimated in 2001 currencies. A sensitivity analysis assessed the robustness of the national annual cost estimates.

RESULTS

In the USA, the total annual medical costs incurred by all payers in managing DN were US dollars 1.9 billion for Type 1 diabetes (range: US dollars 1.0-2.8 billion), US dollars 15.0 billion for Type 2 diabetes (range: US dollars 7.6-22.4 billion), and US dollars 16.8 billion for all diabetes (range: US dollars 8.5-25.2 billion). In the UK, the total annual costs to the National Health Service (NHS) of managing DN were US dollars 231 million ( pound 152 million) for Type 1 diabetes (range: US dollars 190-350 million [ pound 125-230 million]), US dollars 933 million (pound 614 million) for Type 2 diabetes (range: US dollars 809 million-US dollars 1.4 billion [pound 532-927 million]), and US dollars 1.2 billion ( pound 765 million) for all diabetes (range: US dollars 999 million-US dollars 1.8 billion [pound 657 million- pound 1.2 billion]).

CONCLUSIONS

The total annual cost of DN is 13 times greater in the USA than in the UK. Controlling for the substantially higher number of people at risk, the total cost per person with DN and/or a kidney transplant is 40% higher: US dollars 3735 in the USA and US dollars 2672 (pound 1758) in the UK.

Hyperglycemia and hyperlipidemia act synergistically to induce renal disease in LDL receptor-deficient BALB mice

Diabetic nephropathy is the leading cause of end-stage renal disease in Western countries, but only a portion of diabetic patients develop diabetic nephropathy. Dyslipidemia represents an important aspect of the metabolic imbalance in diabetic patients. In this study, we addressed the impact of combined hyperlipidemia and hyperglycemia on renal pathology. Kidneys from wild-type (WT) or LDL receptor-deficient BALB/cBy mice (BALB.LDLR-/-) were examined at 22 weeks of age. Diabetes was induced by administration of streptozotocin and mice were randomly assigned to either standard chow or Western diet. Chow fed BALB.LDLR-/- mice did not demonstrate renal abnormalities, whereas BALB. LDLR-/- mice fed a Western diet showed occasional glomerular and tubulointerstitial foam cells. Diabetic WT mice had modestly increased glomerular cellularity and extracellular matrix. Hyperlipidemic and diabetic BALB.LDLR-/- mice exhibited an increase in glomerular cellularity and extracellular matrix, accumulation of glomerular and tubulointerstitial foam cells and mesangial lipid deposits. The tubular epithelium demonstrated pronounced lipid induced tubular degeneration with increased tubular epithelial cell turnover. Hyperlipidemia and hyperglycemia seem to act synergistically in inducing renal injury in the BALB.LDLR-/- mouse. This model of diabetic nephropathy is unique in its development of tubular lesions and may represent a good model for hyperlipidemia-exacerbated diabetic nephropathy.

Decreased insulin requirement in relation to GFR in nephropathic Type 1 and insulin-treated Type 2 diabetic patients

AIMS

In the presence of impaired renal function, patients require less insulin mainly because insulin clearance is prolonged. The aim of this study was to evaluate the insulin requirement related to glomerular filtration rate (GFR) in nephropathic Type 1 and Type 2 diabetic patients.

METHODS

In a retrospective study we compared insulin requirement in 20 nephropathic Type 1 diabetic patients and 20 insulin-treated Type 2 diabetic patients from the onset of overt nephropathy until the final stage of renal disease. All patients had proteinuria > 0.5 g/24 h and creatinine clearance >/= 80 ml/min per 1.73 m2 at baseline. Creatinine clearance, urinary protein excretion, glycated haemoglobin and the required insulin doses were determined 3- to 6-monthly, basal C-peptide was measured at the beginning and the end of the observation period. The required insulin doses were evaluated at creatinine clearance rates of 80, 60, 40, 20 and 10 ml/min per 1.73 m2 (or at the initiation of dialysis treatment).

RESULTS

The insulin requirement of patients with Type 1 diabetes was reduced from 0.72 +/- 0.16 IU/kg per day at a creatinine clearance rate of 80 ml/min, to 0.45 +/- 0.13 IU/kg per day at a creatinine clearance rate of 10 ml/min (decrement of 38%, P < 0.001). The insulin dose required by Type 2 diabetic patients was reduced from 0.68 +/- 0.28 IU/kg per day at a creatinine clearance rate of 80 ml/min to 0.33 +/- 0.19 IU/kg per day at a clearance rate of 10 ml/min (decrement 51%, P < 0.001). The fall in GFR, urinary protein excretion and glycated haemoglobin levels was similar in the two groups. In patients with Type 2 diabetes, C-peptide levels at the beginning and the end of renal function impairment were 2.2 (0.4-7.3) vs. 2.7 (0.1-4.9) ng/ml (NS). The reduction in insulin requirement was approximately the same in patients with an initial C-peptide level < 1.0 and in those >/= 1.0 ng/ml (decrement 57% vs. 46%).

CONCLUSIONS

The reduction in insulin requirement in renal insufficiency is similar in Type 1 and insulin-treated Type 2 diabetic patients. In subjects with Type 2 diabetes, the residual insulin secretion has no impact on the reduction in insulin requirement dependent on the GFR.

Significance of microalbuminuria in long-duration type 1 diabetes

OBJECTIVE

The value of microalbuminuria (MA) in predicting renal disease and premature mortality in longer duration type 1 diabetes is unclear.

RESEARCH DESIGN AND METHODS

We followed 135 patients with long-standing type 1 diabetes (>30 years' duration) over a 7-year period, recording albuminuria and other clinical variables. Vital status was ascertained and cause of death was recorded.

RESULTS

A total of 27 of 135 patients (20%) died during the follow-up period. Patients with MA (10 of 30, 33.3%) or proteinuria (5 of 6, 83.3%) at initial examination were more likely to die during follow-up than patients who had normal albumin excretion at baseline (12 of 99, 12%; chi(2) for trend 21.9, P < 0.0001). The presence of abnormal albumin excretion and low BMI were independent risk factors of premature death. The causes of death were similar in patients with normal and abnormal urine albumin excretion. A total of 24.4% of initially normoalbuminuric survivors developed MA, and persistent proteinuria developed in 3.5%. Progressors had significantly higher albumin excretion rate at baseline compared with those who remained normoalbuminuric: 9.0 microg/min (3.8-18) vs. 4.0 microg/min (0.4-17.5); P < 0.001. A total of 21% of patients with MA at baseline reverted to normoalbuminuria, and persistent proteinuria developed in 32%. The likelihood of progression to persistent proteinuria was significantly greater in those with baseline MA compared with those with normal albumin excretion (P < 0.001).

CONCLUSIONS

Even in long-standing type 1 diabetes of >30 years' duration, MA and proteinuria predict all-cause mortality. MA is a good predictor of persistent proteinuria.

Microalbuminuria testing in diabetes: is a dipstick as effective as laboratory tests?

The National Service Framework (NSF) for Diabetes (Department of Health, 2002) aims to improve care for people with diabetes. Primary care trusts need to demonstrate the provision of cost-effective and evidence based care. The National Institute for Clinical Excellence guidelines (NICE, 2002) recommend that microalbuminuria is tested annually in people with diabetes, either by a dipstick method or by a laboratory method. A mini systematic review was undertaken to establish whether a dipstick method of detecting microalbuminuria is as effective as a laboratory method. Four databases were searched and studies comparing dipstick and laboratory methods were included. A hand search was also included. The review was further limited to the Micral test II compared to a reference laboratory standard. Four studies met the inclusion criteria and it was concluded that the Micral test II has a high sensitivity but not very high specificity with lower positive predictive value; it was therefore found to be adequate as a screening tool but not as a diagnostic tool. Therefore the Micral II test is not as effective as a laboratory comparator.

Trends in the prevalence of diabetic nephropathy in type 1 and type 2 diabetes

PURPOSE OF REVIEW

To summarize recent trends in the prevalence of nephropathy due to diabetes and to assess the causes of these changes. Such analysis may influence our strategy to reduce the increasing numbers of cases.

RECENT FINDINGS

Registry data show a progressive increase in the number of cases of nephropathy due to type 2 diabetes such that diabetes is now the leading cause of end-stage renal failure. Despite the increasing incidence of type 1 diabetes, European data indicate the numbers of type 1 patients going on to dialysis are stable. The increase in the prevalence of type 2 diabetes, which in itself is related to increasing levels of obesity, is a major factor but the increase in end-stage renal failure is disproportionately greater. Other factors are therefore important such as earlier development of diabetes and better prevention of coronary events. Similar changes are occurring worldwide. Clinical predictors and genetic markers are being studied.

SUMMARY

More active management of proteinuric type 2 diabetic patients is required to achieve the demanding targets recommended on the basis of clinical trial data. However, the figures suggest that only widespread application of public health measures aimed at the epidemic of type 2 diabetes itself will prevent further rapid escalation of the numbers of type 2 patients reaching end-stage renal failure.