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

Comprehending the Role of Metabolic and Hemodynamic Factors Alongside Different Signaling Pathways in the Pathogenesis of Diabetic Nephropathy

Diabetic nephropathy (DN) is a progressive microvascular disorder of diabetes that contributes as a primary reason for end-stage renal disease worldwide. The pathological hallmarks of DN include diffuse mesangial expansion, thicker basement membrane of glomeruli, and arteriole hyalinosis. Hypertension and chronic hyperglycemia are the primary risk factors contributing to the occurrence of DN. The complex pathophysiology of DN involves the interplay amongst metabolic and hemodynamic pathways, growth factors and cytokines production, oxidative stress, and ultimately impaired kidney function. Hyperglycemia-induced vascular dysfunction is the main pathological mechanism that initiates DN. However, several other pathogenic mechanisms, such as oxidative stress, inflammatory cell infiltration, and fibrosis, contribute to disease progression. Different vasoactive hormone processes, including endothelin and renin-angiotensin, are activated as a part of the pathophysiology of DN, which also involves increased intraglomerular and systemic pressure. The pathophysiology of DN will continue to be better understood because of recent developments in genomics and molecular biology, but attempts to develop a comprehensive theory that explains all existing cellular and biochemical pathways have been thwarted by the disease's multifactorial nature. This review extensively discusses the current understanding regarding the metabolic and hemodynamic pathological mechanisms, along with other signaling pathways and molecules responsible for the pathogenesis of DN. This work will encourage a greater in-depth understanding and investigation of the present status of the biochemical mechanistic processes underlying the pathogenesis of DN, which may assist in the determination of different biomarkers and help in the design and development of novel drug candidates in the near future.

Risk of renal complications and death in young and middle-aged Swedes with parental type 1 diabetes: a nation-wide, prospective cohort study

INTRODUCTION

This study aimed to investigate if individuals with childhood-onset type 1 diabetes having a parent with the same condition (parental diabetes) had worse metabolic control and an increased risk of death and renal failure compared with those with parents without type 1 diabetes (sporadic diabetes).

RESEARCH DESIGN AND METHODS

We conducted a population-based cohort study using data from the Swedish Childhood Diabetes Register, including cases with onset of type 1 diabetes before the age of 15 and recorded between 1977 and 2010. The cohort was linked to national registers to compare mortality, renal failure, and glycated hemoglobin (HBA1c) levels.

RESULTS

We identified 16 572 incident cases of childhood-onset type 1 diabetes. Of these, 15 701 had data on parental diabetes status, with 1390 (8.9%) having at least one parent with this condition. HbA1c data were available in 9105 individuals at 20-30 years of age, with the parental group showing higher levels compared with the sporadic diabetes group (8.4% (68 mmol/mol) vs 8.2% (66 mmol/mol), p=0.004). The Cox proportional HR for death in parental diabetes was 1.33 (95% CI 1.00 to 1.75), and the competing risk HR for renal failure was 1.27 (95% CI 1.08 to 1.50). Women in the parental diabetes group had a higher risk of early death (HR 1.79, 95% CI 1.17 to 2.72) compared with the sporadic diabetes group.

CONCLUSIONS

Individuals with parental diabetes had slightly higher HbA1c and elevated risks of renal failure and death compared with those with sporadic diabetes, especially pronounced in women. Although the exact mechanisms behind these differences are unclear, we suggest that individualized care may benefit individuals with parental type 1 diabetes.

Classification of longitudinal estimated glomerular filtration rate trajectories in Canadian adults with type 1 diabetes

AIMS

Type 1 diabetes (T1D) increases the risk of chronic kidney disease (CKD) development. The aims of this study were to classify trajectories of estimated glomerular filtration rate (eGFR) in a cohort of Canadian adults with T1D, and to describe the risk factors associated with declining eGFR trajectories.

METHODS

In this retrospective cohort of adults with T1D, data was collected between 1996 and 2020. CKD was defined as eGFR <60 mL/min/1.73 m2. Latent class mixed models were used to categorize eGFR trajectories. Multinomial logistic regression was used to identify factors associated with declining eGFR trajectories.

RESULTS

In this study, 304 adults were analyzed, with baseline measurements at a median duration of T1D of 15.3 (5.4-24.2) years. Eight percent of the cohort developed CKD over a median duration of 24.3 (13.7-34.8) years. Four classes of longitudinal eGFR trajectories were identified, broadly categorized as steeply declining (SD1, SD2) and gradual declining (GD1, GD2). Female sex, poor glycemic control, elevated body mass index, and albuminuria were associated with a steeply declining trajectory.

CONCLUSION

In this cohort, four distinctive eGFR trajectories were identified, including a subtype with steeply declining eGFR. Given the complex nature of CKD progression, further prospective study of this model for identification of individuals at risk for CKD based on their trajectory of kidney function may support clinicians in their decision-making.

Age at onset of type 1 diabetes between puberty and 30 years old is associated with increased diabetic nephropathy risk

Diabetic nephropathy is a critical complication of patients with type 1 diabetes, while epidemiological studies were scarce among Asian countries. We conducted a cross-sectional study to identify factors associated with diabetic nephropathy by questionnaires, using student's t-test, chi-square test, and multivariable logistic regression. Among 898 participants, 16.7% had diabetic nephropathy. Compared with non-diabetic nephropathy patients, the patients with diabetic nephropathy had significantly higher percentage with onset age of type 1 diabetes between puberty and under 30 years old (female ≥ 12 or male ≥ 13 years old to 29 years old), longer diabetes duration, having family history of diabetes and diabetic nephropathy, accompanied with hypertension, hyperlipidemia, or coronary artery disease (CAD). Compared with patients with onset age before puberty, the odds of diabetic nephropathy occurrence increased to 1.61 times in patients with onset age between puberty and under 30 years old (p = 0.012) after adjusting diabetes duration. Age of diabetes onset between puberty and under 30 years old, diabetes duration, HbA1c, hospital admission within 3 years, diabetic retinopathy, hypertension, systolic blood pressure (SBP), triglyceride levels, and use of angiotensin converting enzyme inhibitor (ACEI) and/or angiotensin receptor blockers (ARB) were independent factors associated with diabetic nephropathy Screening for proteinuria is important in daily clinical practice and should be part of diabetes self-management education for patients with type 1 diabetes.

Characterisation and clinical outcomes in children and adolescents with diabetes according to newly defined subgroups: a cohort study from the DPV registry

Background

Personalised therapy has emerged as a possibly more efficient approach taking disease heterogeneity into account. The aim of this study was to determine whether recently described subgroups of childhood diabetes have prognostic association with diabetes-specific complications and, therefore, might be a basis for personalised therapies.

Methods

We applied a previously developed subgroup classification to pediatric patients (diabetes onset <18 years) from the prospective Diabetes Patient Follow-up (DPV) registry with documented data between January 1, 2000 and March 31, 2022, from diabetes centers in Germany, Austria, Switzerland, and Luxembourg. The classification required information on islet autoantibody status, age, haemoglobin A1c (HbA1c), and body-mass index (BMI-SDS) at disease manifestation, as well as follow up data after 2 and after 4 years, which was available in 22,719 patients. Patients without documented data on these parameters were excluded from the analysis. The cumulative risk of severe hypoglycemia, diabetic ketoacidosis (DKA), retinopathy, and nephropathy were analysed by Kaplan-Meier analyses over a median follow-up of 6.8 years (IQR 4.8-9.6).

Findings

Patients were classified into 10 subgroups (P1-P7 islet autoantibody-positive, n = 19,811; N1-N3 islet autoantibody-negative, n = 2908). The groups varied markedly with respect to specific acute and chronic complications. Severe hypoglycemia was a characteristic feature in young islet autoantibody-positive subgroups P1, P3, P4 (10-year risk 46, 46 and 47%) and the islet autoantibody-negative groups N1, N2 (43 and 46%). Nephropathy was identified in patient groups P2 and P5 (10-year risk 16%), which had features of moderate disease such as preserved C-peptide, low HbA1c, and very low frequency of DKA at diabetes onset. Group P7, which was defined by a high BMI, was associated with poor metabolic control, DKA, and retinopathy. In contrast, islet autoantibody-negative patients with high BMI (N3) had a low risk for all four complications.

Interpretation

Subgrouping of childhood diabetes at diabetes onset provided prognostic value for the development of acute and chronic diabetes-specific complications.

Funding

The DPV initiative is supported by The German Ministry of Education and Research (BMBF) within the German Center for Diabetes Research, the diabetes surveillance of the Robert Koch Institute, the German Diabetes Association (DDG) and INNODIA.

Type 1 diabetes and inborn errors of immunity: Complete strangers or 2 sides of the same coin?

Type 1 diabetes (T1D) is a polygenic disease and does not follow a mendelian pattern. Inborn errors of immunity (IEIs), on the other hand, are caused by damaging germline variants, suggesting that T1D and IEIs have nothing in common. Some IEIs, resulting from mutations in genes regulating regulatory T-cell homeostasis, are associated with elevated incidence of T1D. The genetic spectrum of IEIs is gradually being unraveled; consequently, molecular pathways underlying human monogenic autoimmunity are being identified. There is an appreciable overlap between some of these pathways and the genetic variants that determine T1D susceptibility, suggesting that after all, IEI and T1D are 2 sides of the same coin. The study of monogenic IEIs with a variable incidence of T1D has the potential to provide crucial insights into the mechanisms leading to T1D. These insights contribute to the definition of T1D endotypes and explain disease heterogeneity. In this review, we discuss the interconnected pathogenic pathways of autoimmunity, β-cell function, and primary immunodeficiency. We also examine the role of environmental factors in disease penetrance as well as the circumstantial evidence of IEI drugs in preventing and curing T1D in individuals with IEIs, suggesting the repositioning of these drugs also for T1D therapy.

Childhood diabetes mellitus and early-onset kidney diseases later in life: a nationwide population-based matched cohort study

BACKGROUND

The empirical evidence remains inconclusive for an association between diabetes mellitus (DM) in children and early-onset kidney disease later in life, and little is known about the effects of DM types (i.e., type 1 diabetes [T1DM] and type 2 diabetes [T2DM]) in childhood on type-specific kidney diseases. We aimed to evaluate the association of childhood DM with overall and type-specific early-onset kidney diseases later in life.

METHODS

The population-based matched cohort study included 9356 individuals with DM (T1DM: 8470, T2DM: 886) diagnosed in childhood (&lt; 18 years) who were born between 1977 and 2016, and 93,560 individuals without DM matched on sex and year of birth in Denmark. The main outcomes were overall and type-specific early-onset kidney diseases. The follow-up period of all included participants was from the date of DM diagnosis in the exposure group until the first diagnosis of kidney disease, emigration, or 31 December 2018, whichever came first.

RESULTS

During a median follow-up of 13 years, children with DM had a 154% increased risk of early-onset kidney diseases than children without DM (adjusted hazard ratios 2.54, 95% confidence intervals 2.38-2.72), and T1DM (2.48, 2.31-2.67) and T2DM (2.75, 2.28-3.31) showed similar results. Children with DM also had a higher risk of multiple specific kidney diseases including glomerular diseases, renal tubulo-interstitial diseases, renal failure, and urolithiasis. The risks of type-specific kidney diseases including glomerular diseases and renal failure tended to be higher for children with T2DM (glomerular diseases: 5.84, 3.69-9.24; renal failure: 14.77, 8.53-25.59) than those with T1DM (glomerular diseases: 3.14, 2.57-3.83; renal failure: 8.24, 6.66-10.20).

CONCLUSIONS

Children with DM had a higher increased risk of early-onset overall and specific kidney diseases later in life. Early prevention and treatment of both T1DM and T2DM in childhood may significantly reduce the risk of kidney diseases later in life.

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

OBJECTIVE

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

RESEARCH DESIGN AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Endocrinopathies in Inborn Errors of Immunity

Inborn errors of immunity (IEI), caused by hereditary or genetic defects, are a group of more than 400 disorders, in which the immune system, including lymphocytes, neutrophils, macrophages, and complements, does not function properly. The endocrine system is frequently affected by IEI as an associated clinical feature and a complex network of glands which regulate many important body functions, including growth, reproduction, homeostasis, and energy regulation. Most endocrine disorders associated with IEI are hypofunction which would be treated with supplementation therapy, and early diagnosis and appropriate management are essential for favorable long-term outcomes in patients with IEI. In this review, we aimed to comprehensively summarize and discuss the current understanding on the clinical features and the pathophysiology of endocrine disorders in IEI. This review is composed with three parts. First, we discuss the two major pathophysiology of endocrinopathy in IEI, autoimmune response and direct effects of the responsible genes. Next, the details of each endocrinopathy, such as growth failure, hypothyroidism, hypoparathyroidism, adrenal insufficiency, diabetes mellitus (DM) are specified. We also illustrated potential endocrinopathy due to hematopoietic stem cell transplantation, including hypogonadism and adrenal insufficiency due to glucocorticoid therapy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Decreasing Cumulative Incidence of End-Stage Renal Disease in Young Patients With Type 1 Diabetes in Sweden: A 38-Year Prospective Nationwide Study

OBJECTIVE

Diabetic nephropathy is a serious complication of type 1 diabetes. Recent studies indicate that end-stage renal disease (ESRD) incidence has decreased or that the onset of ESRD has been postponed; therefore, we wanted to analyze the incidence and time trends of ESRD in Sweden.

RESEARCH DESIGN AND METHODS

In this study, patients with duration of type 1 diabetes >14 years and age at onset of diabetes 0-34 years were included. Three national diabetes registers were used: the Swedish Childhood Diabetes Register, the Diabetes Incidence Study in Sweden, and the National Diabetes Register. The Swedish Renal Registry, a national register on renal replacement therapy, was used to identify patients who developed ESRD.

RESULTS

We found that the cumulative incidence of ESRD in Sweden was low after up to 38 years of diabetes duration (5.6%). The incidence of ESRD was lower in patients with type 1 diabetes onset in 1991-2001 compared with onset in 1977-1984 and 1985-1990, independent of diabetes duration.

CONCLUSIONS

The risk of developing ESRD in Sweden in this population is still low and also seems to decrease with time.

Predictors of renal complications in pediatric patients with type 1 diabetes mellitus: A prospective cohort study

AIMS

Diabetic Nephropathy (DN) is rarely encountered in childhood, otherwise early subclinical abnormalities are detectable few years after diabetes diagnosis. Our aim was to evaluate the incidence rate of microalbuminuria in childhood onset type 1 diabetes (DM1) patients. Secondary aim was to examine which variables could influence the development of DN.

METHODS

We longitudinally evaluated 137 young patients with DM1 from diagnosis (1994-2004) for a median of 11.8 years (1st-3rd q: 9.7-15.0). Overnight albumin excretion rate, degree of metabolic control, presence of microangiopathic complications and autoimmune co-morbidities were retrospectively collected.

RESULTS

DN was observed in 16/137 cases (11.7%), with an incidence rate of 10.0 per 1000 person-years. Young T1D patients with persistent micro/macro-albuminuria were more likely to have higher HbA1c concentrations over the last four years (P = 0.04), and were more likely to have retinopathy (P = 0.011) and subclinical peripheral neuropathy (P = 0.003).

CONCLUSIONS

DN predictors were age at DM1 diagnosis and mean HbA1c levels. Even if DN incidence is lower than reported, periodical screening is mandatory. Moreover, borderline microalbuminuria as additional risk factor deserves attention.

Incidence of End-Stage Renal Disease in Patients With Type 1 Diabetes

OBJECTIVE

To investigate how risk of end-stage renal disease (ESRD) among patients with type 1 diabetes has changed over time and further how the risk is affected by age, sex, and time period of diagnosis of diabetes.

RESEARCH DESIGN AND METHODS

A cohort including all patients <30 years old diagnosed with type 1 diabetes in Finland in 1965-2011 was followed until start of renal replacement therapy, death, or end of follow-up at the end of 2013. Altogether, 29,906 patients were included. The main outcome was cumulative risk of ESRD, accounting for death as a competing risk.

RESULTS

The patients were followed up for a median of 20 years. During 616,403 patient-years, 1,543 ESRD cases and 4,185 deaths were recorded. The cumulative risk of ESRD was 2.2% after 20 years and 7.0% after 30 years from the diabetes diagnosis. The relative risk of ESRD was 0.13 (95% CI 0.08-0.22) among patients diagnosed in 1995-2011 compared with those diagnosed in 1965-1979. Patients <5 years old at the time of diagnosis had the lowest risk of ESRD after diagnosis. With the cumulative risk of ESRD estimated from time of birth, the patients aged 5-9 years at diabetes diagnosis were at highest risk.

CONCLUSIONS

The cumulative risk of ESRD has decreased markedly during the past five decades. This highlights the importance of modern treatment of diabetes and diabetic nephropathy.

Low Incidence of End-Stage Renal Disease in Childhood-Onset Type 1 Diabetes Followed for Up to 42 Years

OBJECTIVE

End-stage renal disease (ESRD) is one of the most severe complications in type 1 diabetes. We aimed to estimate the cumulative incidence of ESRD in individuals with childhood-onset type 1 diabetes followed for up to 42 years.

RESEARCH DESIGN AND METHODS

Data were based on the nationwide, population-based Norwegian Childhood Diabetes Registry and included case patients with new-onset type 1 diabetes (age <15 years) who had received a diagnosis during the periods 1973-1982 and 1989-2012. Follow-up took place until the development of ESRD, death, emigration, or 30 November 2015. We estimated the cumulative incidence of ESRD by linking to the Norwegian Renal Registry.

RESULTS

Among the 7,871 patients, representing 147,714 person-years of follow-up, ESRD developed in 103 individuals (1.3%). The mean time from the diagnosis of diabetes to the development of ESRD was 25.9 years (range 12.7-39.1). The cumulative incidence of ESRD was 0.7% (95% CI 0.4-1.0) at 20 years' diabetes duration, 2.9% (2.3-3.7) at 30 years' duration, and 5.3% (4.3-6.5) at 40 years' duration. The risk of the development of ESRD was lower in women than in men (hazard ratio [HR] 0.61; 95% CI 0.41-0.91) and higher in individuals in whom diabetes had been diagnosed at 10-14 years of age compared with those in whom it was diagnosed before 10 years of age (HR 1.29; 1.06-1.56). We did not identify any significant difference in the risk of the development of ESRD between those in whom diabetes was diagnosed in 1973-1982 and in 1989-2012 (HR 0.80; 0.45-1.45).

CONCLUSIONS

We report a very low incidence of ESRD among patients with childhood-onset diabetes in Norway. The risk was lower in women compared with men and in individuals in whom diabetes was diagnosed at a younger age.

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

OBJECTIVE

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

RESEARCH DESIGN AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Risk of Microvascular Complications and Macrovascular Risk Factors in Early-Onset Type 1 Diabetes after at Least 10 Years Duration: An Analysis of Three Population-Based Cross-Sectional Surveys in Germany between 2009 and 2016

AIMS

To estimate the risk of microvascular complications and macrovascular risk factors among persons with early-onset (diagnosed at ages 0 to <5 years) and long-duration type 1 diabetes and determine temporal trends and associations with potential predictors.

METHODS

We conducted three population-based cross-sectional surveys in Germany (N = 1789) to obtain information on exposures and five outcomes (retinopathy, nephropathy, dyslipidemia, hypertension, and a composite endpoint combining all four outcomes). For each outcome, log-binomial spline regression was applied to estimate the risk and dose-response relationship with diabetes duration and exposures.

RESULTS

The risk for microvascular complications increased after 14 years since diabetes diagnosis whereas dyslipidemia and hypertension were already prevalent at 10 years. The 15-year risk (95% confidence interval) of the composite endpoint for female and male patients was 22.9% (18.8%-27.9%) and 19.2% (15.5%-23.8%), respectively. Temporal trends suggested a decreasing risk between 2009 and 2016. Glycemic control, lifestyle-related factors, and SES, but not health care-related factors, were associated with the risk of the composite endpoint.

CONCLUSIONS

In early-onset type 1 diabetes, there exists a considerable risk of complications and comorbidities already in young ages. Future research should focus on prevention of diabetic complications in young patients and clarification of pathways of the associations found.

Marginal structural model to evaluate the joint effect of socioeconomic exposures on the risk of developing end-stage renal disease in patients with type 1 diabetes: a longitudinal study based on data from the Swedish Childhood Diabetes Study Group

PURPOSE

Diabetic nephropathy is a severe complication of type 1 diabetes (T1D) that may lead to renal failure and end-stage renal disease (ESRD) demanding dialysis and transplantation. The etiology of diabetic nephropathy is multifactorial and both genes and environmental and life style-related factors are involved. In this study, we investigate the effect of the socioeconomic exposures, unemployment and receiving income support, on the development of ESRD in T1D patients, using a marginal structural model (MSM) in comparison with standard logistic regression models.

METHODS

The study is based on the Swedish Childhood Diabetes Register which in 1977 started to register patients developing T1D before 15 years of age. In the analyses, we include patients born between 1965 and 1979, developing diabetes between 1977 and 1994, and followed until 2013 (n = 4034). A MSM was fitted to adjust for both baseline and time-varying confounders.

RESULTS

The main results of the analysis indicate that being unemployed for more than 1 year and receiving income support are risk factors for the development of ESRD. Multiple exposures over time to these risk factors increase the risk associated with the disease.

CONCLUSIONS

Using a MSM is an advanced method well suited to investigate the effect of exposures on the risk of complications of a chronic disease with longitudinal data. The results show that socioeconomic disadvantage increases the risk of developing ESRD in patients with T1D.

Incidence of diabetes-related complications in Chinese patients with type 1 diabetes: a population-based longitudinal cohort study in Taiwan

OBJECTIVE

To estimate the incidence densities and cumulative incidence of diabetes-related complications in patients with type 1 diabetes for a maximum of 15-year follow-up. The estimations were further stratified by gender and age at diagnosis (ie, early onset: 0-12 years, late onset:≥13 years).

DESIGN

A population-based retrospective longitudinal cohort study.

SETTING

Taiwan's National Health Insurance medical claims.

PARTICIPANTS

4007 patients newly diagnosed with type 1 diabetes were identified during 1999-2012.

OUTCOME MEASURES

Acute complications included diabetic ketoacidosis (DKA) and hypoglycaemia. Chronic complications were cardiovascular diseases (CVD), retinopathy, neuropathy and nephropathy.

RESULTS

The incidence density of retinopathy was greatest (97.74 per 1000 person-years), followed by those of nephropathy (31.36), neuropathy (23.93) and CVD (4.39). Among acute complications, the incidence density of DKA was greatest (121.11 per 1000 person-years). The cumulative incidences of acute complications after 12 years following diagnosis were estimated to be 52.1%, 36.1% and 4.1% for DKA, outpatient hypoglycaemia and hospitalised hypoglycaemia, respectively. For chronic complications, the cumulative incidence of retinopathy after 12 years following diagnosis was greatest (65.2%), followed by those of nephropathy (30.2%), neuropathy (23.7%) and CVD (4.1%). Females with late-onset diabetes were greatly affected by advanced retinopathy (ie, sight-threatening diabetic retinopathy) and hospitalised hypoglycaemia, whereas those with early-onset diabetes were more vulnerable to DKA. Chronic complications were more commonly seen in late-onset diabetes, whereas early-onset diabetes were most affected by acute complications.

CONCLUSIONS

Ethnic Chinese patients with type 1 diabetes were greatly affected by DKA and retinopathy. The incidence of diabetes-related complications differed by age at diagnosis and sex.

Incidence of and risk factors for hospitalisations due to vascular complications: A population-based type 1 diabetes cohort (n=1316) followed into early adulthood

AIM

To determine the incidence of hospitalisations and risk factors for vascular complications experienced during early adulthood in patients with childhood onset type 1 diabetes.

METHODS

A population-based childhood onset type 1 diabetes cohort was identified from a statewide register (1992-2012). Data linkage was used to identify a matched comparison cohort. Hospital admissions data were extracted to follow up both cohorts into early adulthood (1975-2012).

RESULTS

The type 1 diabetes cohort (n=1316) had a mean age of diagnosis of 9.5years, 49.5% were women and mean age at the end of follow-up was 26.3years (range 18-38). Within the type 1 diabetes cohort 32 (2.4%) were hospitalised with a vascular complication during early adulthood. Poor glycaemic control during paediatric management was associated with a significant increase in risk for ophthalmic complication with 19.4% (n=12/62) of those with a mean HbA1c >12% (108mmol/mol) diagnosed compared to 0.72% (n=5/696) of those with mean HbA1c <9% (75mmol/mol), adjusted hazard ratio 8.4 (95% CI 2.0, 34.7).

CONCLUSION

Severe vascular complications requiring hospital admission continue to be observed during early adulthood. Both women and those with poor glycaemic control are at increased risk of requiring a hospital admission for these complications during early adulthood.

Socio-economic factors influencing the development of end-stage renal disease in people with Type 1 diabetes - a longitudinal population study

AIMS

The development of end-stage renal disease (ESRD) in Type 1 diabetes is multifactorial. Familial socio-economic factors may influence adherence to and understanding of diabetes treatment, and also general health behaviour. We investigate how parental and personal education level and exposure to low economic status, indicated by the need for income support, influence the development of ERSD caused by Type 1 diabetes.

METHODS

Participants were retrieved from the nationwide Swedish Childhood Diabetes Registry, which was linked to the Swedish Renal Registry, to find people with ESRD caused by Type 1 diabetes, and to Statistic Sweden to retrieve longitudinal socio-economic data on participants and their parents. Data were analysed using Cox regression modelling.

RESULTS

Of 9287 people with diabetes of duration longer than 14 years, 154 had developed ESRD due to diabetes. Median diabetes duration (range) for all participants was 24.2 years (14.0-36.7 years). Low maternal education (≤ 12 years) more than doubled the risk of developing ESRD, hazard ration (HR) = 2.9 [95% confidence interval (95% CI): 1.7-4.8]. For people with a low personal level of education HR was 5.7 (3.4-9.5). In an adjusted model, the person's own education level had the highest impact on the risk of ESRD. If at least one of the parents had ever received income support the HR was 2.6 (1.9-3.6).

CONCLUSIONS

Socio-economic factors, both for the parents and the person with diabetes, have a strong influence on the development of ESRD in Type 1 diabetes. It is important for caregivers to give enough support to more vulnerable people and their families.

Parity and mortality in cases of childhood-onset diabetes mellitus

AIMS

This study aims to assess the association between parity and mortality in adults with childhood-onset type 1 diabetes (T1D) and their matched controls.

METHODS

Individual data (308 617 person-years) on mortality and the reproductive histories of a Finnish cohort of 2307 women and 2819 men with T1D, each with two matched controls, were obtained from the National Population Register. All persons with diabetes had been diagnosed with T1D in 1965-1979 at the age of 17 or under.

RESULTS

All-cause mortality in people without offspring was significantly higher than that in people with children among both people with diabetes and non-diabetic control persons in both sexes (all p-values <0.01). In men with offspring, the decrease of mortality rate compared with men without offspring was less marked among those with diabetes (9% reduction in mortality hazard ratio (HR) with one offspring, 47% with two) than among those without diabetes (33% HR (p = 0.025) and 61% HR (p = 0.023) reduction, respectively). In women with offspring, the association between parity and mortality was independent of diabetes status. Having at least two offspring was associated with a decreased hazard of diabetes-related death regardless of sex; among women with diabetes, even having one offspring was associated with a decreased hazard of dying from diabetes (HR = 0.46; 95% CI 0.31, 0.69).

CONCLUSIONS

The association between parity and mortality follows different patterns in men and women with T1D. To what extent this reflects effects of health on family planning decisions in people with T1D cannot be defined without further studies. Copyright © 2016 John Wiley & Sons, Ltd.

Clinical predictive factors in diabetic kidney disease progression

Diabetic kidney disease (DKD) represents a major component of the health burden associated with type 1 and type 2 diabetes. Recent advances have produced an explosion of ‘novel’ assay‐based risk markers for DKD, though clinical use remains restricted. Although many patients with progressive DKD follow a classical albuminuria‐based pathway, non‐albuminuric DKD progression is now well recognized. In general, the following clinical and biochemical characteristics have been associated with progressive DKD in both type 1 and type 2 diabetes: increased hemoglobin A1c, systolic blood pressure, albuminuria grade, early glomerular filtration rate decline, duration of diabetes, age (including pubertal onset) and serum uric acid; the presence of concomitant microvascular complications; and positive family history. The same is true in type 2 diabetes for male sex category, in patients following an albuminuric pathway to DKD, and also true for the presence of increased pulse wave velocity. The following baseline clinical characteristics have been proposed as risk factors for DKD progression, but with further research required to assess the nature of any relationship: dyslipidemia (including low‐density lipoprotein, total and high‐density lipoprotein cholesterol); elevated body mass index; smoking status; hyperfiltration; decreases in vitamin D, hemoglobin and uric acid excretion (all known consequences of advanced DKD); and patient test result visit‐to‐visit variability (hemoglobin A1c, blood pressure and high‐density lipoprotein cholesterol). The development of multifactorial ‘renal risk equations’ for type 2 diabetes has the potential to simplify the task of DKD prognostication; however, there are currently none for type 1 diabetes‐specific populations. Significant progress has been made in the prediction of DKD progression using readily available clinical data, though further work is required to elicit the role of several variables, and to consolidate data to facilitate clinical implementation.

Recent trends in life expectancy for people with type 1 diabetes in Sweden

AIMS/HYPOTHESIS

People with type 1 diabetes have reduced life expectancy (LE) compared with the general population. Our aim is to quantify mortality changes from 2002 to 2011 in people with type 1 diabetes in Sweden.

METHODS

This study uses health records from the Swedish National Diabetes Register (NDR) linked with death records. Abridged period life tables for those with type 1 diabetes aged 20 years and older were derived for 2002-06 and 2007-11 using Chiang's method. Cox proportional hazard models were used to assess trends in overall and cause-specific mortality.

RESULTS

There were 27,841 persons aged 20 years and older identified in the NDR as living with type 1 diabetes between 2002 and 2011, contributing 194,685 person-years of follow-up and 2,018 deaths. For men with type 1 diabetes, the remaining LE at age 20 increased significantly from 47.7 (95% CI 46.6, 48.9) in 2002-06 to 49.7 years (95% CI 48.9, 50.6) in 2007-11. For women with type 1 diabetes there was no significant change, with an LE at age 20 of 51.7 years (95% CI 50.3, 53.2) in 2002-06 and 51.9 years (95% CI 50.9, 52.9) in 2007-11. Cardiovascular mortality significantly reduced, with a per year HR of 0.947 (95% CI 0.917, 0.978) for men and 0.952 (95% CI 0.916, 0.989) for women.

CONCLUSIONS/INTERPRETATION

From 2002-06 to 2007-11 the LE at age 20 of Swedes with type 1 diabetes increased by approximately 2 years for men but minimally for women. These recent gains have been driven by reduced cardiovascular mortality.

Age at menarche and the risk of diabetic microvascular complications in patients with type 1 diabetes

AIMS/HYPOTHESIS

The aim of this study was to evaluate the relationship among age at onset of diabetes, age at onset of menarche and risk of diabetic nephropathy and laser-treated retinopathy in type 1 diabetes.

METHODS

Data related to age at menarche were collected through questionnaires and were available for 1,304 women who participated in the Finnish Diabetic Nephropathy Study (FinnDiane). A possible association between age at menarche and diabetic nephropathy and retinopathy was investigated.

RESULTS

There was an inverse relationship between the age at onset of diabetes and age at menarche: the younger the age at onset of diabetes, the higher the age at menarche (p < 0.0001). A non-linear relationship between the age of menarche and risk of diabetic microvascular complications was found in patients with diabetes onset before menarche, but there was no such association in patients with diabetes onset after menarche. Women with delayed menarche (> mean age + 2 years) had a 2.30 (95% CI 1.27, 4.17; p < 0.006) times higher risk of nephropathy compared with the women who underwent menarche at the mean age ± 2 years. Delayed menarche also increased the risk of retinopathy (OR 2.34 [95% CI 1.36, 4.01]). After excluding patients with nephropathy, the OR for retinopathy was 2.11 (95% CI 1.15, 3.90). Earlier menarche (< mean age - 2 years) did not have any effect on this risk.

CONCLUSIONS/INTERPRETATION

Delayed menarche was associated with an increased risk of diabetic nephropathy and retinopathy, whereas early menarche was not. Delayed menarche may be used as a new tool to identify women at risk of diabetic microvascular complications.

All-cause mortality in a nationwide cohort of childhood-onset diabetes in Norway 1973-2013

AIMS/HYPOTHESIS

The aim of this study was to assess the association between all-cause mortality and sex, age at diagnosis and year of diagnosis in Norwegian patients with childhood-onset diabetes.

METHODS

The study was based on the nationwide, population-based Norwegian Childhood Diabetes Registry, which includes all newly diagnosed cases of childhood-onset diabetes at age 0-14 years in 1973-1982 and 1989-2012 (n = 7,884). Patients were followed until date of death, emigration or 30 September 2013.

RESULTS

Among the 7,884 patients, representing 132,420 person-years, 249 (3.2%) died during a mean follow-up of 16.8 (range 0.0-40.7) years. The standardised mortality ratio (SMR) for the total cohort was 3.6 (95% CI 3.1, 4.0), increasing by attained age. Absolute mortality was significantly lower in females than in males (HR 0.50 [95% CI 0.38, 0.65]), although the SMRs were similar. Cox regression analysis showed a significant decrease in mortality of 49% (HR 0.51 [95% CI 0.28, 0.93]) for those diagnosed in 1999-2012 compared with those diagnosed in 1973-1982 (p = 0.03).

CONCLUSIONS/INTERPRETATION

In spite of improved diabetes care, mortality is still three to four times higher in those with childhood-onset diabetes compared with the general population in Norway. However, absolute mortality has declined among children diagnosed most recently (1999-2012) compared with those diagnosed in the earliest period (1973-1982).

Renal replacement therapy due to type 1 diabetes; time trends during 1995-2010--a Swedish population based register study

BACKGROUND

End stage renal disease (ESRD), is the most severe complication of diabetes mellitus. This population-based study analysed time trends for start of renal replacement therapy (RRT) due to type 1 diabetes compared to type 2 diabetes and other diagnoses.

MATERIAL AND METHODS

We used data on patients who were registered 1995-2010 in the Swedish Renal Registry, a nationwide register covering 95 % of all patients with uraemia. The patients were analysed according to their original kidney disease. The incidence was analysed by calendar year, age at start of RRT and gender.

RESULTS

Of 17389 patients who were registered, 1833 had type 1 diabetes; 65% were men. The mean age at onset of RRT for patients with type 1 diabetes was 52.8 years which increased by more than 3 years over the studied period. The number of patients in need of RRT due to type 1 diabetes decreased, while RRT due to type 2 diabetes increased during the period studied.

CONCLUSIONS

The overall incidence of RRT in Sweden is rather constant over the years but the need for RRT in type 1 diabetes patients decreased and patients with type 1 diabetes tend to become older at onset of RRT.

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.

Impact of sex and age at onset of diabetes on mortality from ischemic heart disease in patients with type 1 diabetes

OBJECTIVE To study whether ischemic heart disease (IHD) mortality among patients with type 1 diabetes (T1D) depends on the age at onset of diabetes and whether this effect is sex specific. RESEARCH DESIGN AND METHODS The study examined long-term IHD-specific mortality in a Finnish population-based cohort of patients with early-onset (0-14 years) and late-onset (15-29 years) T1D (n = 17,306). RESULTS During 433,782 person-years of follow-up, 478 deaths from IHD were observed. Within the early-onset cohort, the average crude mortality rate in women was 33.3% lower than in men, whereas in the late-onset cohort, mortality was only one-half that in men. In contrast, the standardized mortality ratio (SMR) was higher in women than in men (21.6 [95% CI 17.2-27.0] vs. 5.8 [5.1-6.6]). The difference in SMR between sexes was more striking in the early-onset cohort (women 52.8 [36.3-74.5], men 12.1 [9.2-15.8]). The SMR was also greater in women in the late-onset cohort (15.8 [11.8-20.7]) compared with men (5.0 [4.3-5.8]). The relative risk of dying from IHD was greatest in women aged <40 years and 40-60 years in the early- and late-onset cohorts, respectively. CONCLUSIONS The risk of mortality from IHD is exceptionally high in women with early-onset T1D compared with women in the background population. These observations underscore the importance of identifying risk factors early in women and delivering more-aggressive treatment after diagnosis.

Autonomic neuropathy in young people with type 1 diabetes: a systematic review

Autonomic neuropathy is an under-recognized complication of diabetes, although it affects multiple organ systems and has widespread clinical manifestations including orthostatic hypotension, exercise intolerance, gastroparesis, diarrhea, constipation, and urinary incontinence. The most severe consequences include hypoglycemia unawareness and cardiovascular dysfunction. Autonomic neuropathy is also implicated in sudden unexplained deaths in otherwise healthy young people--the ‘dead in bed syndrome’. In adults, cardiovascular autonomic neuropathy is an independent predictor of mortality, predominantly due to cardiovascular disease, nephropathy, and hypoglycemia. While overt autonomic neuropathy is rare in childhood and adolescence, subclinical signs of autonomic dysfunction are common, and can be found soon after diabetes diagnosis. Risk factors for autonomic neuropathy in young people include diabetes duration, poor glycemic control, and presence of aldose reductase gene (AKR1B1) polymorphisms, specifically the Z-2/Z-2 genotype. Autonomic dysfunction is accelerated by puberty.

Predictors of diabetic nephropathy

Diabetic nephropathy (DN) is a leading cause of morbidity and mortality in diabetic patients representing a huge health and economic burden. Alarming recent data described diabetes as an unprecedented worldwide epidemic, with a prevalence of ∼6.4% of the world population in 2010, while the prevalence of CKD among diabetics was approximately 40%. With a clinical field hungry for novel markers predicting DN, several clinical and laboratory markers were identified lately with the promise of reliable DN prediction. Among those are age, gender, hypertension, smoking, sex hormones and anemia. In addition, eccentric left ventricular geometric patterns, detected by echocardiography, and renal hypertrophy, revealed by ultrasonography, are promising new markers predicting DN development. Serum and urinary markers are still invaluable elements, including serum uric acid, microalbuminuria, macroalbuminuria, urinary liver-type fatty acid-binding protein (u-LFABP), and urinary nephrin. Moreover, studies have illustrated a tight relationship between obstructive sleep apnea and the development of DN. The purpose of this review is to present the latest advances in identifying promising predictors to DN, which will help guide the future research questions in this field. Aiming at limiting this paramount threat, further efforts are necessary to identify and control independent modifiable risk factors, while developing an integrative algorithm for utilization in DN future screening programs.

The influence of gender and sexual hormones on incidence and outcome of chronic kidney disease

It has long been known that the female sex is associated with a better clinical outcome in chronic renal diseases. Although many experimental, clinical, and epidemiological studies in adults have attempted to explain the difference in disease progression between females and males, a definitive understanding of the underlying mechanisms is still lacking. Hormone-modulating therapies are being increasingly used for various indications (such as post-menopausal hormone replacement, estrogen- or androgen-receptor antagonists for cancer therapy). Therefore, a deeper knowledge of the interaction between sexual hormones and progression of kidney disease is important, as hormone-modulating therapy for non-renal indication may influence both kidney structure and function. In addition, specific modulation of the sexual hormone system, such as the use of selective estrogen receptor modulators, may represent a therapeutic option for patients with renal diseases. Although conclusive data on this topic in the pediatric population are still lacking, the aim of this review is to familiarize pediatric nephrologists with gender-specific differences in renal physiology, pathophysiology, and the progression of kidney diseases. Experimental models that analyze the effects of sexual hormones on renal structure and function are discussed. It is hoped that this review will stimulate researchers to focus on pediatric studies that will provide a deeper insight into the interaction of gender hormones and the kidney both before and during puberty.

Infant and toddler type 1 diabetes: complications after 20 years' duration

OBJECTIVE

To compare the effect of the prepubertal duration of diabetes on the occurrence of complications in two groups of patients after the same number of years of the disease.

RESEARCH DESIGN AND METHODS

This multicenter study enrolled 105 patients aged 16-40.3 years; 53 were prepubertal at diagnosis (aged 0-3) and 52 were pubertal (Tanner stage) and aged 9-14.9. The mean duration of disease was 19.8 and 19.5 years for prepubertal and pubertal patients, respectively. In all patients, retinal photographs were taken and centrally graded. Urinary albumin excretion (UAE; 86 case subjects), blood pressure (BP; 89 case subjects), and lifetime HbA(1c) (72 case subjects) were also evaluated.

RESULTS

The prevalence of diabetic retinopathy (DR) was higher in pubertal than in prepubertal patients, both for any grade DR (71 vs. 40%, P = 0.002) and for mild or more severe DR (P = 0.005). The prevalence of abnormal UAE was not different in the two groups. Hypertension was found only in three patients, all pubertal at diagnosis. In the small group with moderate-to-severe DR, lifetime HbA(1c) levels, as percentages above the upper normal reference value, were higher (P < 0.01) in prepubertal than in pubertal patients.

CONCLUSIONS

If diabetes is diagnosed in infants or toddlers and the prepubertal duration of diabetes is very long, the patients seem to be protected against DR. This protection disappears if lifetime metabolic control is bad. Instead, when onset is at puberty, the DR risk is higher and less dependent on metabolic control and may be influenced by age-related factors, such as BP.

[Autoimmune comorbidity and microvascular complications in childhood-onset type 1 diabetes after 20 years of diabetes duration: a questionnaire study]

There are no population-based data on the autoimmune morbidity and vascular complications of young adults with childhood-onset type 1 diabetes in Hungary.

AIMS

To assess the prevalence of these morbidities after 20 years of diabetes duration.

METHOD

Postal questionnaire.

RESULTS

6.2% of the patients had celiac disease. Diabetes was diagnosed at a significantly earlier age in patients with diabetes and celiac disease as compared to those without celiac diasease. Thyroid autoimmunity was reported in 7.6% of cases. They were significantly older with longer duration of diabetes. Every fifth patients reported retinopathy, one sixth of patients was treated for hypertension. Neuropathy was found in 3.4% and kidney disease in 4.8% of the cases.

CONCLUSIONS

Apart from retinopathy and hypertension, the prevalence of microvascular complications was relatively low. Considering the limitations of questionnaire studies, laboratory screening is warranted to assess the true prevalence of comorbidities and complications.

Sex differences in the development of kidney disease in individuals with type 1 diabetes mellitus: a contemporary analysis

BACKGROUND

Kidney disease in patients with type 1 diabetes historically has been believed to be more prevalent in men. Because recent data do not reflect this pattern, we evaluated whether a sex difference persists.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

We used 18-year follow-up data from the Pittsburgh Epidemiology of Diabetes Complications Study (n = 788; baseline mean age, 27 years; diabetes duration, 19 years).

PREDICTOR OR FACTOR

Sex and diagnosis interval (1950-1964 or 1965-1980).

OUTCOMES

Cumulative incidences of macroalbuminuria (albumin excretion rate >200 μg/min) and end-stage renal disease (ESRD; kidney failure, dialysis, or transplant) were evaluated at 20, 25, and 30 years of diabetes duration. To address potential survival bias, death certificate information was included in determining ESRD for those who died before baseline (n = 145). Analyses were stratified by diagnosis year (1950-1964 or 1965-1980).

OTHER MEASUREMENTS

Kidney disease risk factor information was available.

RESULTS

A significant interaction was noted between sex and diagnosis cohort for ESRD incidence by 25 (P = 0.002) and 30 (P < 0.001) years' duration. Thus, within the 1950-1964 cohort (210 men and 180 women), ESRD incidence was higher in men compared with women by 25 (30.6% vs 18.0%, respectively) and 30 (43.4% vs 24.6%, respectively) years' duration of type 1 diabetes. However, in the 1965-1980 cohort (260 men and 283 women), the incidence was higher in women (7.6% vs 13.8% by 25 years [P = 0.04] and 13.7% vs 21.0% by 30 years' duration [P = 0.09] in men vs women, respectively). Results were similar for macroalbuminuria.

LIMITATIONS

Study participants were not followed up from the onset of diabetes; thus, risk-factor data from that period are lacking.

CONCLUSIONS

Our data suggest that the male excess of type 1 diabetic kidney disease cases observed in the earlier cohort has been eliminated in the younger cohort. The reason for this dramatic change presently is unclear, but should be addressed in subsequent studies.

Sex-related differences in the long-term risk of microvascular complications by age at onset of type 1 diabetes

AIMS/HYPOTHESIS

This study examined sex-related differences in the cumulative risk of proliferative retinopathy (PR) and end-stage renal disease (ESRD) over 40 years of duration of type 1 diabetes according to age at diabetes onset.

METHODS

We assessed 4,416 patients from the Finnish Diabetic Nephropathy Study population. Kaplan-Meier analysis was used to provide cumulative incidence rates and Cox regression analyses for HRs.

RESULTS

There were no sex-related differences in the cumulative incidence of ESRD in patients diagnosed with type 1 diabetes between 0 to 4 and 5 to 9 years. Thereafter the risk started to diverge. The cumulative incidence of ESRD in patients diagnosed between 10 to 14 and ≥15 years was 17.4% (95% CI 13.4-21.2) and 13.0% (9.6-16.2) respectively in women, while in men it was 32.2% (28.0-36.1) and 24.6% (20.8-28.1) respectively. The respective HRs were (onset at 10 to 14 years) 1.9 (p < 0.0001) and (onset at ≥15 years) 1.8 (p < 0.001), respectively. There was no difference in the risk of PR between men and women diagnosed between 0 and 4 years of age, but progressive sex-related differences in the cumulative incidence of PR were observed with increasing age at onset. The HRs for men in the age-at-onset groups 5 to 9, 10 to 14 and ≥15 years of age were 1.3 (95% CI 1.0-1.6), 1.3 (1.1-1.6) and 2.1 (1.6-2.6) compared with women in these groups, respectively.

CONCLUSIONS/INTERPRETATION

The difference between the sexes with regard to risk of diabetic microvascular complications is highly dependent on the age at onset of diabetes. The risk of ESRD and PR risk doubled in men compared with women when age at onset was ≥15 years.

Association between testosterone, estradiol and sex hormone binding globulin levels in men with type 1 diabetes with nephropathy

Male sex is a risk factor for development and progression of diabetic nephropathy; however, the relationship between sex hormone levels and diabetic nephropathy in type 1 diabetic men is unknown. This was a prospective follow-up study as part of the nationwide Finnish Diabetic Nephropathy (FinnDiane) Study; 297 patients were followed for 5.9+/-1.5 years. Serum total testosterone (Tt) and estradiol (Te), calculated free testosterone (cFt) and estradiol (cFe) and sex hormone binding globulin were measured at baseline and correlated with urinary albumin excretion rate, estimated glomerular filtration rate and markers of metabolic syndrome. Diabetes without renal disease was associated with decreased Tt (p<0.001), Te (p<0.001) and cFt (p=0.001) levels compared with healthy non-diabetic men. With progression of renal disease from micro- to macroalbuminuria, this decrease in serum Tt was even more pronounced. Cox regression showed that cFt and cFe were independent predictors of the progression from macroalbuminuria to end-stage renal disease. Our study shows that men with type 1 diabetes exhibit dysregulated sex hormone levels, which is most pronounced in men with progressive renal disease, suggesting that sex hormones may play a role in the pathogenesis of diabetic nephropathy associated with type 1 diabetes.

Risk markers of future microalbuminuria and hypertension based on clinical and morphological parameters in young type 1 diabetes patients

BACKGROUND

Nephropathy is a severe complication of type 1 diabetes and develops in 30% of patients. Currently, it is not possible to identify young patients at risk prior to the development of microalbuminuria (MA) and/or hypertension (HT).

OBJECTIVE

To study predictors of MA and/or HT in young normoalbuminuric (NA) patients with type 1 diabetes.

SUBJECTS AND METHODS

Forty-six NA and normotensive (NT) type 1 diabetes patients, regularly followed since onset with checks on metabolic control, kidney function, and MA, were investigated with kidney biopsies and 24-h ambulatory blood pressure measurements (ABPMs) after 10.6 yr of diabetes. The patients were followed another six and a half years with regard to the development of MA and HT.

RESULTS

Fifteen patients developed MA and/or HT during follow-up. The strongest risk markers were poor metabolic control after puberty, high day-time systolic blood pressure (BP), and increased BMT at 10 yr, which explained 62% of the outcome for MA and/or HT at 17 yr duration with 77% sensitivity and 65% specificity. The threshold values were long-term postpubertal HbA(1c) > 8.2%, day-time systolic BP > 130 mmHg, and BMT > 490 nm/1.73 m(2).

CONCLUSIONS

Normoalbuminuric and NT patients at risk of developing MA and HT could be identified and might benefit from an early start of antihypertensive therapy and improvement of metabolic control.

Cumulative risk, age at onset, and sex-specific differences for developing end-stage renal disease in young patients with type 1 diabetes: a nationwide population-based cohort study

OBJECTIVE

This study aimed to estimate the current cumulative risk of end-stage renal disease (ESRD) due to diabetic nephropathy in a large, nationwide, population-based prospective type 1 diabetes cohort and specifically study the effects of sex and age at onset.

RESEARCH DESIGN AND METHODS

In Sweden, all incident cases of type 1 diabetes aged 0-14 years and 15-34 years are recorded in validated research registers since 1977 and 1983, respectively. These registers were linked to the Swedish Renal Registry, which, since 1991, collects data on patients who receive active uremia treatment. Patients with > or =13 years duration of type 1 diabetes were included (n = 11,681).

RESULTS

During a median time of follow-up of 20 years, 127 patients had developed ESRD due to diabetic nephropathy. The cumulative incidence at 30 years of type 1 diabetes duration was low, with a male predominance (4.1% [95% CI 3.1-5.3] vs. 2.5% [1.7-3.5]). In both male and female subjects, onset of type 1 diabetes before 10 years of age was associated with the lowest risk of developing ESRD. The highest risk of ESRD was found in male subjects diagnosed at age 20-34 years (hazard ratio 3.0 [95% CI 1.5-5.7]). In female subjects with onset at age 20-34 years, the risk was similar to patients' diagnosed before age 10 years.

CONCLUSIONS

The cumulative incidence of ESRD is exceptionally low in young type 1 diabetic patients in Sweden. There is a striking difference in risk for male compared with female patients. The different patterns of risk by age at onset and sex suggest a role for puberty and sex hormones.

Occurrence of microalbuminuria in young people with Type 1 diabetes: importance of age and diabetes duration

AIMS

To determine the occurrence of microalbuminuria in young people with Type 1 diabetes mellitus followed prospectively for 2 years and to relate the presence of persistent elevations in urinary albumin excretion (UAE) to age, diabetes duration, puberty and other factors.

METHODS

During a 2 year period, random urine samples were obtained from 471 patients, aged 8-18 years (mean +/-sd 12.9 +/- 2.3 years) with Type 1 diabetes duration 5.6 +/- 3.0 years, as part of routine clinical care. Urine albumin and creatinine concentrations were measured in 1310 samples (median, 3 samples per patient) and the albumin:creatinine ratio was calculated (in micrograms albumin per milligram creatinine). Height, weight, blood pressure (BP), glycated haemoglobin (HbA(1c)), blood glucose monitoring frequency and Tanner staging were collected from patients' medical records.

RESULTS

Twenty-three per cent of patients had one or more sample with elevated UAE (> or =20 microg/mg) and 9.3% had persistent elevations (> or =2 samples > or =20 microg/mg). Those with and without persistent microalbuminuria did not differ significantly in age, diabetes duration, z-score for body mass index, pubertal status or BP percentile. Ten per cent of children <13 years old and 9% of children > or =13 years old had persistent microalbuminuria. Persistent microalbuminuria was significantly associated with diabetes duration only in older children (duration 0.5-3 years, 4%; 4-6 years, 8%; > or =7 years, 14%; P = 0.02, trend test). Mean HbA(1c) over the 2 years was 8.7 +/- 1.2%. In a logistic regression model, mean HbA(1c) was the only significant predictor of persistent microalbuminuria (odds ratio 1.3, 95% confidence interval 1.0-1.6, P = 0.05).

CONCLUSIONS

Microalbuminuria in older children with Type 1 diabetes is likely to be clinically significant. In younger children, it may reflect functional, reversible renal changes. Longitudinal analysis is needed to confirm the probable transient nature of microalbuminuria in young patients with Type 1 diabetes.

Oxidant/antioxidant status and hyperfiltration in young patients with type 1 diabetes mellitus

Diabetic nephropathy (DN), a major cause of morbidity and mortality in diabetes, will develop within a subset of type 1 diabetes mellitus (T1DM) patients, and oxidative stress has been implicated in its pathogenesis. To investigate the relationship between indicators of early DN stages (hyperfiltration estimated by creatinine clearance > or =150 ml/min per 1.73 m(2), microalbuminuria) and oxidative stress, a prospective study was conducted in 29 T1DM patients (age 13.89 +/- 4.61 years) and 18 control subjects (age 13.23 +/- 3.99 years). Blood samples were collected to assay for biomarkers of oxidative stress (malondialdehyde and carbonyl groups) and antioxidants (glutathione peroxidase, reduced glutathione, alpha-tocopherol, and beta-carotene). With respect to control subjects, in T1DM patients, an increase was found in biomarkers of oxidative stress (p < 0.05), mainly due to the group of subjects with hyperfiltration, and a decrease in the ratio alpha-tocopherol/lipids (p < 0.05). In multiple regression analyses, age at disease onset, glycated hemoglobin, microalbuminuria, and oxidative stress biomarkers remained as explicative variables of hyperfiltration (R (2) adjusted = 0.731, p = 0.000). These findings support the importance of the oxidative damage to lipids and proteins, which is linked to hyperfiltration and which could contribute to the development of DN in patients with T1DM.

Estrogens and the diabetic kidney

BACKGROUND

Across all ages, the incidence and rate of progression of most nondiabetic renal diseases are markedly higher in men compared with age-matched women. These observations suggest that female sex may be renoprotective. In the setting of diabetes, however, this female protection against the development and progression of renal disease is diminished.

OBJECTIVE

This review aimed to summarize our current understanding of sex differences in the development and progression of diabetic renal disease, and of the contribution of sex hormones, particularly estrogens, to the pathophysiology of this disease. We also attempted to answer why female sex does not protect the diabetic kidney.

METHODS

Using terms such as gender, sex, diabetes, diabetic nephropathy, estrogens, and sex hormones, the PubMed database was searched for English-language articles; targeted searches were conducted using terms such as gender/sex differences in diabetic renal disease. No restrictions were imposed on publication dates.

RESULTS

Although the existing data regarding the sex differences in the incidence and progression of diabetic renal disease are inconclusive, the undisputed fact is that women with either type 1 or type 2 diabetes mellitus exhibit a much higher incidence of renal disease compared with nondiabetic women. It is conceivable that the loss of female sex as a renoprotective factor in diabetes may be related to the abnormal regulation of sex hormone concentrations. Both clinical and experimental data suggest that diabetes may be associated with an imbalance in estradiol concentrations. Supplementation with 17beta-estradiol or administration of selective estrogen receptor modulators reduces the incidence of diabetes and attenuates the progression of diabetic renal disease.

CONCLUSIONS

Serum concentrations of ovarian hormones may provide a new means for predicting future risk of renal complications in diabetes. Exogenous steroid hormones may be an effective treatment for attenuating the progression of diabetic nephropathy.

Hospitalization for vascular complications in childhood onset type 1 diabetes--effects of gender and age at onset

AIMS

To study the cumulative incidence of hospitalization for severe diabetic vascular complications in childhood onset type 1 diabetes patients with special regards to age at onset and gender.

METHODS

The Swedish Childhood Diabetes Register (SCDR) was linked to the Swedish Hospital Discharge Register up to 31 December 2004. The following diagnoses were traced: diabetic kidney disease, myocardial infarction, stroke, lower limb arterial disease and diabetes with multiple complications. Cox proportional hazards survival method was applied with the following covariates: maternal age, birthweight deviation from gestational week standard, age at onset and gender.

RESULTS

Until 31 December 9974 children had been followed for at least 10 years corresponding to 141 839 person years at risk and 103 (7.3 per 1000 person years) had been hospitalized at least once at the maximum duration of follow-up of 26 years. Diabetic kidney disease was the most common cause of hospitalization and 63 patients had more than one diabetic complication. Female gender (RR=2.02, 95% CI=1.05-3.89) and age at onset of diabetes (RR=1.37, 95% CI=1.20-1.56) were significant risk factors for severe complication.

CONCLUSIONS

Hospitalization for severe diabetic complications at a maximum follow-up of 26 years is rather low in Sweden. There is a higher hospitalization rate among females than among males, and also among patients diagnosed with diabetes after 10 years of age than among patients diagnosed before the age of 10 years.

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.

Diabetic nephropathy in 27,805 children, adolescents, and adults with type 1 diabetes: effect of diabetes duration, A1C, hypertension, dyslipidemia, diabetes onset, and sex

OBJECTIVE

To give an up-to-date profile of nephropathy and the involvement of risk factors in a large, prospective cohort of patients with type 1 diabetes and largely pediatric and adolescent onset of disease.

RESEARCH DESIGN AND METHODS

A total of 27,805 patients from the nationwide, prospective German Diabetes Documentation System survey were included in the present analysis. Inclusion criteria were at least two documented urine analyses with identical classification. Urine analyses, treatment regimens, diabetes complications, and risk factors were recorded prospectively. Baseline characteristics were age at diagnosis 9.94 years (median [interquartile range 5.8-14.3]), age at last visit 16.34 years (12.5-22.2), and follow-up time 2.5 years (0.43-5.3). Cumulative incidence of nephropathy was tested by Kaplan-Meier analysis and association with risk factors by logistic regression.

RESULTS

Nephropathy was classified as normal in 26,605, microalbuminuric in 919, macroalbuminuric in 78, and end-stage renal disease (ESRD) in 203 patients. After calculated diabetes duration of 40 years, 25.4% (95% CI 22.3-28.3) had microalbuminuria and 9.4% (8.3-11.4) had macroalbuminuria or ESRD. Risk factors for microalbuminuria were diabetes duration (odds ratio 1.033, P < 0.0001), A1C (1.13, P < 0.0001), LDL cholesterol (1.003, P < 0.0074), and blood pressure (1.008, P < 0.0074), while childhood diabetes onset (1.011, P < 0.0001) was protective. Male sex was associated with the development of macroalbuminuria.

CONCLUSIONS

Diabetes duration, A1C, dyslipidemia, blood pressure, and male sex were identified as risk factors for nephropathy. Therefore, besides the best possible metabolic control, early diagnosis and prompt treatment of dyslipidemia and hypertension is mandatory in patients with type 1 diabetes.

Pre-pubertal induction of experimental diabetes protects against early renal macrophage infiltration

The present study was undertaken to identify whether the age at induction of experimental diabetes modifies macrophage infiltration in the kidney. Renal macrophage infiltration was studied 10 days after the induction of experimental diabetes in 4-week-old pre-pubertal and 12-week-old adult male rats of normotensive [Wistar-Kyoto (WKY) rats] and hypertensive (spontaneously hypertensive rats, SHRs) background. Renal macrophage infiltration was evaluated by immunohistochemistry for ED1. Plasma glucose levels were similar in all diabetic groups. Adult SHRs were hypertensive, and induction of diabetes did not alter blood pressure (BP) in any group. Induction of diabetes in pre-pubertal rats did not induce macrophage infiltration in the kidney. However, in adult rats, tubulointerstitial macrophage infiltration was increased in both WKY (22.86 +/- 3.93 vs 7.86 +/- 2.16 per high-power field, P < 0.001) and SHR (26.41 +/- 5.91 vs 11.48 +/- 1.23, P < 0.001) groups after induction of diabetes. Glomerular macrophage infiltration was also increased after induction of diabetes in the adult WKY group (1.83 +/- 0.50 vs 1.16 +/- 0.26 per glomerular cross section, P = 0.029), which was not significant in the adult SHRs (2.52 +/- 0.34 vs 1.95 +/- 0.35). We conclude that the pre-pubertal induction of diabetes apparently protects against early renal macrophage infiltration, while the induction of diabetes in adults induces exaggerated macrophage infiltration in the kidney.