Adolescent type 1 Diabetes Cardio-renal Intervention Trial (AdDIT)

Abnormal vascular thickness and stiffness in young adults with type 1 diabetes: new insights from cutting-edge ultrasound modalities

BACKGROUND

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in patients with Type 1 Diabetes (T1D). Early markers of CVD include increased carotid intima-media thickness (CIMT) and pulse wave velocity (PWV), but these existing ultrasound technologies show limited spatial and temporal resolution in young adults. The purpose of this study is to evaluate the utility of high-resolution ultrasound modalities, including high frequency ultrasound CIMT (hfCIMT) and ultrafast ultrasound PWV (ufPWV), in young adults with Type 1 Diabetes.

METHODS

This is a prospective single-center observational cohort study including 39 participants with T1D and 25 age and sex matched controls. All participants underwent hfCIMT and ufPWV measurements. hfCIMT and ufPWV measures of T1D were compared with controls and associations with age, sex, BMI, A1c, blood pressure, and lipids were studied.

RESULTS

Mean age was 24.1 years old in both groups. T1D had a greater body mass index (27.7 [5.7] vs 23.1 [3.2] kg/m2), LDL Cholesterol, and estimated GFR, and had a mean A1c of 7.4 [1.0] % (57 mmol/mol) and diabetes duration of 16.1 [3.7] years with 56% using insulin pumps. In T1D, hfCIMT was significantly increased as compared to controls (0.435 ± 0.06 mm vs 0.379 ± 0.06 mm respectively, p < 0.01). ufPWV measures were significantly increased in T1D (systolic foot PWV: 5.29 ± 0.23 m/s vs 5.50 ± 0.37 m/s, p < 0.01; dicrotic notch PWV = 7.54 ± 0.46 m/s vs 7.92 ± 0.41 m/s, p < 0.01). Further, there was an impact of A1c-measured glycemia on hfCIMT, but this relationship was not seen with ufPWV. No significant statistical correlations between hfCIMT and ufPWV measures in either T1D or healthy controls were observed.

CONCLUSION

Young adults with T1D present with differences in arterial thickness and stiffness when compared with controls. Use of novel high-resolution ultrasound measures describe important relationships between early structural and vascular pathophysiologic changes and are promising tools to evaluate pre-clinical CVD risk in youth with T1D.

TRIAL REGISTRATION

ISRCTN91419926.

Interactive Effects of Empagliflozin and Hyperglycemia on Urinary Amino Acids in Individuals With Type 1 Diabetes

Optimizing energy use in the kidney is critical for normal kidney function. Here, we investigate the effect of hyperglycemia and sodium-glucose cotransporter 2 (SGLT2) inhibition on urinary amino acid excretion in individuals with type 1 diabetes (T1D). The open-label ATIRMA trial assessed the impact of 8 weeks of 25 mg empagliflozin orally once per day in 40 normotensive normoalbuminuric young adults with T1D. A consecutive 2-day assessment of clamped euglycemia and hyperglycemia was evaluated at baseline and posttreatment visits. Principal component analysis was performed on urinary amino acids grouped into representative metabolic pathways using MetaboAnalyst. At baseline, acute hyperglycemia was associated with changes in 25 of the 33 urinary amino acids or their metabolites. The most significant amino acid metabolites affected by acute hyperglycemia were 3-hydroxykynurenine, serotonin, glycyl-histidine, and nicotinic acid. The changes in amino acid metabolites were reflected by the induction of four biosynthetic pathways: aminoacyl-tRNA; valine, leucine, and isoleucine; arginine; and phenylalanine, tyrosine, and tryptophan. In acute hyperglycemia, empagliflozin significantly attenuated the increases in aminoacyl-tRNA biosynthesis and valine, leucine, and isoleucine biosynthesis. Our findings using amino acid metabolomics indicate that hyperglycemia stimulates biosynthetic pathways in T1D. SGLT2 inhibition may attenuate the increase in biosynthetic pathways to optimize kidney energy metabolism.

ARTICLE HIGHLIGHTS

Blood pressure control for diabetic retinopathy

BACKGROUND

Diabetic retinopathy is a common complication of diabetes and a leading cause of visual impairment and blindness. Research has established the importance of blood glucose control to prevent development and progression of the ocular complications of diabetes. Concurrent blood pressure control has been advocated for this purpose, but individual studies have reported varying conclusions regarding the effects of this intervention.

OBJECTIVES

To summarize the existing evidence regarding the effect of interventions to control blood pressure levels among diabetics on incidence and progression of diabetic retinopathy, preservation of visual acuity, adverse events, quality of life, and costs.

SEARCH METHODS

We searched several electronic databases, including CENTRAL, and trial registries. We last searched the electronic databases on 3 September 2021. We also reviewed the reference lists of review articles and trial reports selected for inclusion.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in which either type 1 or type 2 diabetic participants, with or without hypertension, were assigned randomly to more intense versus less intense blood pressure control; to blood pressure control versus usual care or no intervention on blood pressure (placebo); or to one class of antihypertensive medication versus another or placebo.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently reviewed the titles and abstracts of records identified by the electronic and manual searches and the full-text reports of any records identified as potentially relevant. The included trials were independently assessed for risk of bias with respect to outcomes reported in this review.

MAIN RESULTS

We included 29 RCTs conducted in North America, Europe, Australia, Asia, Africa, and the Middle East that had enrolled a total of 4620 type 1 and 22,565 type 2 diabetic participants (sample sizes from 16 to 4477 participants). In all 7 RCTs for normotensive type 1 diabetic participants, 8 of 12 RCTs with normotensive type 2 diabetic participants, and 5 of 10 RCTs with hypertensive type 2 diabetic participants, one group was assigned to one or more antihypertensive agents and the control group to placebo. In the remaining 4 RCTs for normotensive participants with type 2 diabetes and 5 RCTs for hypertensive type 2 diabetic participants, methods of intense blood pressure control were compared to usual care. Eight trials were sponsored entirely and 10 trials partially by pharmaceutical companies; nine studies received support from other sources; and two studies did not report funding source. Study designs, populations, interventions, lengths of follow-up (range less than one year to nine years), and blood pressure targets varied among the included trials. For primary review outcomes after five years of treatment and follow-up, one of the seven trials for type 1 diabetics reported incidence of retinopathy and one trial reported progression of retinopathy; one trial reported a combined outcome of incidence and progression (as defined by study authors). Among normotensive type 2 diabetics, four of 12 trials reported incidence of diabetic retinopathy and two trials reported progression of retinopathy; two trials reported combined incidence and progression. Among hypertensive type 2 diabetics, six of the 10 trials reported incidence of diabetic retinopathy and two trials reported progression of retinopathy; five of the 10 trials reported combined incidence and progression. The evidence supports an overall benefit of more intensive blood pressure intervention for five-year incidence of diabetic retinopathy (11 studies; 4940 participants; risk ratio (RR) 0.82, 95% confidence interval (CI) 0.73 to 0.92; I2 = 15%; moderate certainty evidence) and the combined outcome of incidence and progression (8 studies; 6212 participants; RR 0.78, 95% CI 0.68 to 0.89; I2 = 42%; low certainty evidence). The available evidence did not support a benefit regarding five-year progression of diabetic retinopathy (5 studies; 5144 participants; RR 0.94, 95% CI 0.78 to 1.12; I2 = 57%; moderate certainty evidence), incidence of proliferative diabetic retinopathy, clinically significant macular edema, or vitreous hemorrhage (9 studies; 8237 participants; RR 0.92, 95% CI 0.82 to 1.04; I2 = 31%; low certainty evidence), or loss of 3 or more lines on a visual acuity chart with a logMAR scale (2 studies; 2326 participants; RR 1.15, 95% CI 0.63 to 2.08; I2 = 90%; very low certainty evidence). Hypertensive type 2 diabetic participants realized more benefit from intense blood pressure control for three of the four outcomes concerning incidence and progression of diabetic retinopathy. The adverse event reported most often (13 of 29 trials) was death, yielding an estimated RR 0.87 (95% CI 0.76 to 1.00; 13 studies; 13,979 participants; I2 = 0%; moderate certainty evidence). Hypotension was reported in two trials, with an RR of 2.04 (95% CI 1.63 to 2.55; 2 studies; 3323 participants; I2 = 37%; low certainty evidence), indicating an excess of hypotensive events among participants assigned to more intervention on blood pressure.

AUTHORS' CONCLUSIONS

Hypertension is a well-known risk factor for several chronic conditions for which lowering blood pressure has proven to be beneficial. The available evidence supports a modest beneficial effect of intervention to reduce blood pressure with respect to preventing diabetic retinopathy for up to five years, particularly for hypertensive type 2 diabetics. However, there was a paucity of evidence to support such intervention to slow progression of diabetic retinopathy or to affect other outcomes considered in this review among normotensive diabetics. This weakens any conclusion regarding an overall benefit of intervening on blood pressure in diabetic patients without hypertension for the sole purpose of preventing diabetic retinopathy or avoiding the need for treatment for advanced stages of diabetic retinopathy.

Relationship between risk factors for impaired bone health and HR-pQCT in young adults with type 1 diabetes

OBJECTIVE

In type 1 diabetes, risk factors associated with impaired bone health contribute to increased risk of fracture. The aim of this study was to (1): compare the high-resolution peripheral quantitative computed tomography (HR-pQCT) parameters of young adults with type 1 diabetes with those of healthy controls (2), identify sex differences, and (3) evaluate the association between diabetes and bone health risk factors, with HR-pQCT.

METHODS

This is a cross-sectional study in young Canadian adults with childhood onset type 1 diabetes. Z-scores were generated for HR-pQCT parameters using a large healthy control database. Diet, physical activity, BMI, hemoglobin A1C (A1C) and bone health measures were evaluated, and associations were analyzed using multivariate regression analysis.

RESULTS

Eighty-eight participants (age 21 ± 2.2 years; 40 males, 48 females, diabetes duration 13.9 ± 3.4 years) with type 1 diabetes were studied. Low trabecular thickness and elevated cortical geometry parameters were found suggesting impaired bone quality. There were no sex differences. Significant associations were found: Vitamin D (25(OH)D) with trabecular parameters with possible synergy with A1C, parathyroid hormone with cortical parameters, BMI with cortical bone and failure load, and diabetes duration with trabecular area.

CONCLUSIONS

Our data suggests impairment of bone health as assessed by HR-pQCT in young adults with type 1 diabetes. Modifiable risk factors were associated with trabecular and cortical parameters. These findings imply that correction of vitamin D deficiency, prevention and treatment of secondary hyperparathyroidism, and optimization of metabolic control may reduce incident fractures.

Evaluation of novel glomerular filtration rate estimation equations in adolescents and young adults with type 1 diabetes

AIMS

Individuals with type 1 diabetes (T1D) are at an increased risk of chronic kidney disease making estimation of glomerular filtration rate (eGFR) an important component of diabetes care. Which eGFR equation is most appropriate to use in patients with T1D during the transition to adult care is unclear. We, therefore, sought to evaluate the performance of five eGFR equations in adolescents and young adults with T1D.

METHODS

Measured iohexol-based glomerular filtration rate was compared to the Chronic Kidney Disease and Epidemiology Collaboration (CKD-EPI) eGFR, Chronic Kidney Disease in Children (CKiD) eGFR, and three recently developed age-adjusted versions of these in 53 patients with T1D and preserved GFR using bias, precision, and accuracy.

RESULTS

The best performance was found in the sex-dependent CKiD equation (bias: -0.8, accuracy: 11.8 ml/min/1.73 m²). Bias and accuracy (26.4 and 26.8 ml/min/1.73 m²) were worst in the CKD-EPI equation. Age-dependent adjustment improved performance for this equation (bias: 5.3, accuracy: 13.4 ml/min/1.73 m²), but not for the CKiD equation (bias: 15.5, accuracy: 18.8 ml/min/1.73 m²).

CONCLUSION

Age-adjustment improved performance for the CKD-EPI equation, but not for the CKiD equation. The sex-adjusted CKiD equation performed best out of all equations.

Comparison of Clinical and Social Characteristics of Canadian Youth Living With Type 1 and Type 2 Diabetes

OBJECTIVES

Our aim in this study was to describe the clinical and social characteristics of 2 Canadian cohorts of adolescents with diabetes.

METHODS

Participants from the Improving renal Complications in Adolescents with type 2 diabetes through REsearch (iCARE) study (n=322) and the Early Determinants of Cardio-Renal Disease in Youth With Type 1 Diabetes (n=199) study were compared.

RESULTS

Adolescents were 10 to 18 years of age (mean ± standard deviation: 14.8±2.4 years). The T2DM cohort had a shorter duration of diabetes. Both groups had glycated hemoglobin levels above target. The type 2 diabetes (T2D) cohort was comprised of predominantly Indigenous youth. The type 1 diabetes (T1D) cohort was 58.3% European/Caucasian, with a high proportion (41.7%) of visible minority groups (Afro-Caribbean, Asian/Pacific Islander, Hispanic). The prevalence of obesity, hypertension, left ventricular hypertrophy, albuminuria and hyperfiltration was higher in the T2D cohort. The T1D cohort was more socially and economically advantaged in all 4 dimensions of health inequality.

CONCLUSIONS

There are significant differences in clinical and social characteristics of adolescents with T2D and T1D in Canada. Both have inadequate glycemic control with evidence of onset and progression of diabetes-related complications.

Metformin Delays the Development of Atherosclerosis in Type 1 Diabetes Mellitus via the Methylglyoxal Pathway

INTRODUCTION

The aim of our study was to determine the effect of metformin administration on juvenile type 1 diabetes mellitus and atherosclerosis in apolipoprotein E null (ApoE^-/-) mice and to explore the mechanism involved.

METHODS

Eighteen male ApoE^-/- mice were injected with streptozotocin to induce diabetes (diabetic group) and 18 mice who received no streptozotocin injection were assigned to the control (non-diabetic) group. Six mice in each group were then orally administered metformin, simvastatin, or vehicle, respectively, following which the mice were euthanized and tissue samples collected.

RESULTS

Fasting plasma glucose, low-density lipoprotein-cholesterol, and triglyceride concentrations were significantly higher in the three diabetic groups than in the three non-diabetic groups. Plasma N^∈-(carboxymethyl)lysine and N^∈-(carboxyethyl)lysine concentrations were higher in the diabetic mice than in the non-diabetic mice, but metformin treatment reduced these concentrations more effectively than simvastatin. All three diabetic groups demonstrated obvious arterial plaques, but these were largest in the vehicle-treated diabetic group. The expression of extracellular nitric oxide synthase was highest in the simvastatin-treated non-diabetic group, and in diabetic mice it was higher in the simvastatin-treated group than in the other two groups. No significant expression of AMP-activated protein kinase (AMPK) was measured in the three diabetic groups, but a low level of AMPK expression was detected in the non-diabetic groups.

CONCLUSIONS

Metformin can limit the development of atherosclerosis secondary to diabetes in young diabetic mice. A possible mechanism is the removal of methylglyoxal, thereby reducing the formation of advanced glycation endproducts, rather than by lowering the blood glucose level.

FUNDING

This work was supported by the National Natural Science Foundation of China (81901106) and Jinan clinical medical science and technology innovation plan (201907002).

Effect of early glycemic control on HbA1c tracking and development of vascular complications after 5 years of childhood onset type 1 diabetes: Systematic review and meta-analysis

OBJECTIVE

A systematic review and meta-analysis was conducted to investigate if glycemic control measured by glycated hemoglobin (HbA1c) levels near diagnosis are predictive of future glycemic outcomes and vascular complications in childhood onset type 1 diabetes (T1D).

METHODS

Evidence was gathered using electronic databases (MEDLINE, EMBASE, Web of Science, CINAHL, Scopus, and Cochrane Library up to February 2017) and snowballing techniques. Studies investigating the association between the exposure "early glycemic control" and main outcome: "tracking of early control" and secondary outcome: risk of future complications; in children and young people aged 0 to 19 years at baseline; were systematically double-reviewed, quality assessed, and outcome data extracted for synthesis and meta-analysis.

FINDINGS

Five studies (N = 4227 participants) were eligible. HbA1c levels were sub-optimal throughout the study period but tended to stabilize in a "track" by 6 months after T1D diagnosis. The group with low HbA1c <53 mmol/mol (<7%) at baseline had lower long-term HbA1c levels than the higher HbA1c group. The estimated standardized mean difference between the sub groups showed a reduction of HbA1c levels on average by 1.6% (range -0.95% to -2.28%) from baseline. Only one study investigated the association between early glycemic control and development of vascular complications in childhood onset T1D.

INTERPRETATIONS

Glycemic control after the first few months of childhood onset T1D, remains stable but sub-optimal for a decade. The low and high HbA1c levels at baseline seem to "track" in their respective tracks during the 10-year follow-up, however, the initial difference between groups narrows over time.

PROSPERO

CRD42015024546 http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015024546.

A new strategy for vascular complications in young people with type 1 diabetes mellitus

Diabetes vascular complications, including cardiovascular disease, diabetic nephropathy and retinopathy, have a negative effect on the long-term prognosis of young people with type 1 diabetes mellitus (T1DM). Poor glycaemic control and consequent increased HbA_1c levels are major risk factors for the development of vascular complications. HbA_1c levels are the main focus of current management strategies; however, the recommended target is rarely achieved in adolescents. Thus, a clear need exists for improved biomarkers to identify high-risk young people early and to develop new intervention strategies. Evidence is accumulating that early increases in urinary albumin excretion could be predictive of adolescents with T1DM who are at an increased risk of developing vascular complications, independent of HbA_1c levels. These findings present an opportunity to move towards the personalized care of adolescents with T1DM, which takes into consideration changes in albumin excretion and other risk factors in addition to HbA_1c levels.

Social Determinants of Health Are Associated with Markers of Renal Injury in Adolescents with Type 1 Diabetes

OBJECTIVE

To examine the relationship between the social determinants of health and markers of early renal injury in adolescent patients with type 1 diabetes (T1D).

STUDY DESIGN

Renal outcomes included estimated glomerular filtration rate (eGFR) and albumin-creatinine excretion ratio (ACR). Differences in urinary and serum inflammatory markers also were assessed in relation to social determinants of health. Regression analysis was used to evaluate the association between the Ontario Marginalization Index (ON-Marg) as a measure of the social determinants of health, patient characteristics, ACR, eGFR, and renal filtration status (hyperfiltration vs normofiltration).

RESULTS

Participants with T1D (n = 199) with a mean age of 14.4 ± 1.7 years and diabetes duration of 7.2 ± 3.1 years were studied. Mean eGFR was 122.0 ± 19.4 mL/min/1.73 m². Increasing marginalization was positively associated with eGFR (P < .0001) but not with ACR (P = .605). Greater marginalization was associated with greater median levels of urinary interleukin (IL)-2, IL-12 (p40), macrophage-derived chemokine, monocyte chemoattractant protein-3, and tumor necrosis factor-β and serum IL-2. ON-Marg was significantly associated with eGFR after we controlled for age, sex, body mass index z score, ethnicity, serum glucose, and hemoglobin A1c in linear regression. A similar association between hyperfiltration and ON-Marg score was observed in multivariable logistic regression.

CONCLUSION

Increasing marginalization is significantly associated with both eGFR and hyperfiltration in adolescents with T1D and is associated with significant changes in urinary inflammatory biomarkers. These findings highlight a potentially important interaction between social and biological determinants of health in adolescents with T1D.

The Adolescent Cardio-Renal Intervention Trial (AdDIT): retinal vascular geometry and renal function in adolescents with type 1 diabetes

AIMS/HYPOTHESIS

We examined the hypothesis that elevation in urinary albumin creatinine ratio (ACR) in adolescents with type 1 diabetes is associated with abnormal retinal vascular geometry (RVG) phenotypes.

METHODS

A cross-sectional study at baseline of the relationship between ACR within the normoalbuminuric range and RVG in 963 adolescents aged 14.4 ± 1.6 years with type 1 diabetes (median duration 6.5 years) screened for participation in AdDIT. A validated algorithm was used to categorise log10 ACR into tertiles: upper tertile ACR was defined as 'high-risk' for future albuminuria and the lower two tertiles were deemed 'low-risk'. RVG analysis, using a semi-automated computer program, determined retinal vascular calibres (standard and extended zones) and tortuosity. RVG measures were analysed continuously and categorically (in quintiles: Q1-Q5) for associations with log10 ACR and ACR risk groups.

RESULTS

Greater log10 ACR was associated with narrower vessel calibres and greater tortuosity. The high-risk group was more likely to have extended zone vessel calibres in the lowest quintile (arteriolar Q1 vs Q2-Q5: OR 1.67 [95% CI 1.17, 2.38] and venular OR 1.39 [0.98, 1.99]) and tortuosity in the highest quintile (Q5 vs Q1-Q4: arteriolar OR 2.05 [1.44, 2.92] and venular OR 2.38 [1.67, 3.40]). The effects of retinal vascular calibres and tortuosity were additive such that the participants with the narrowest and most tortuous vessels were more likely to be in the high-risk group (OR 3.32 [1.84, 5.96]). These effects were independent of duration, blood pressure, BMI and blood glucose control.

CONCLUSIONS/INTERPRETATION

Higher ACR in adolescents is associated with narrower and more tortuous retinal vessels. Therefore, RVG phenotypes may serve to identify populations at high risk of diabetes complications during adolescence and well before onset of clinical diabetes complications.

Temporal trends and characteristics of clinical trials for which only one racial or ethnic group is eligible

BACKGROUND

Increasing diversity in clinical trials may be worthwhile. We examined clinical trials that restricted eligibility to a single race or ethnicity.

METHODS

We reviewed 19,246 trials registered on ClinicalTrials.gov through January 2013. We mapped trial ZIP-codes to U.S. Census and American Community Survey data. The outcome was whether trials required participants to be from a single racial or ethnic group.

RESULTS

In adjusted analyses, the odds of trials restricting eligibility to a single race/ethnicity increased by 4% per year (95% CI 1.01-1.08, p = .024). Behavioral (5.79% with single race/ethnicity requirements), skin-related (4.49%), and Vitamin D (6.14%) studies had higher rates of single race/ethnicity requirements. Many other trial-specific characteristics, such as funding agency and region of the U.S. in which the trial opened, were associated with eligibility restrictions. In terms of neighborhood characteristics, studies with single race eligibility requirements were more likely to be located in ZIP-codes with greater percentages of those self-reporting the characteristic. For example, 35.2% (SD = 24.9%) of the population self-reported themselves as Black or African American in ZIP-codes with trials requiring participants to be Black/African American, but only 5.9% (SD = 6.9%) self-reported themselves as Black/African American in ZIP-codes with trials that required Asian ethnicity. In ZIP-codes with trials requiring Asian ethnicity, 24.6% (SD = 16.2%) self-reported as Asian. In ZIP-codes with trials requiring Hispanic/Latino ethnicity, 33.3% (SD = 28.5%) self-reported as Hispanic/Latino. Neighborhood level poverty rates and reduced English language ability were also associated with more single race eligibility requirements.

CONCLUSIONS

In selected fields, there has been a modest temporal increase in single race/ethnicity inclusion requirements. Some studies may not fall under regulatory purview and hence may be less likely to include diverse samples. Conversely, some eligibility requirements may be related to health disparities research. Future work should examine whether targeted enrollment criteria facilitates development of personalized medicine or reduces trial access.

Early changes of arterial elasticity in Type 1 diabetes with microvascular complications - A cross-sectional study from childhood to adulthood

AIM

To examine the trajectory of small artery elasticity (SAE) and pulse pressure (PP) in people with Type 1 diabetes and non-diabetic controls across the lifespan, and explore associations with microvascular complications (CX+).

METHODS

This cross-sectional study included 477 Type 1 diabetes patients (188 with CX+, 289 without CX-) and 515 controls. Relationships between SAE and PP and age were evaluated using segmented linear regression. Logistic regression was used to assess the associations between microvascular complications (retinopathy and/or nephropathy) and SAE and PP.

RESULTS

SAE peaked significantly later among controls than diabetic patients CX- vs. CX+ (21.2 vs. 20.4 vs. 17.6 years respectively, p < 0.001). In adults, mean SAE was significantly lower in CX+ vs. CX- vs. controls (6.8 vs. 7.8 vs. 8.0 ml/mm Hg × 10; p < 0.0001), and mean PP was significantly higher in CX+ vs CX- and controls (60 vs. 55 vs. 53 mm Hg; p < 0.0001).

CONCLUSION

Type 1 diabetes CX+ subjects have an earlier peak and decline in SAE relative to CX- and controls, who did not differ. Lower SAE and higher PP were associated with increased odds of Type 1 diabetes complications in adults. These clinically applicable techniques demonstrate an association between accelerated vascular aging and vascular complications in diabetes.

Modifiable Risk Factors for Cardiovascular Disease in Children with Type 1 Diabetes: Can Early Intervention Prevent Future Cardiovascular Events?

PURPOSE OF REVIEW

Patients with type 1 diabetes have increased risk for cardiovascular disease. The purpose of this review is to examine the following: i) current evidence for subclinical cardiovascular disease (CVD) in children with type 1 diabetes (T1DM) ii) known modifiable risk factors for CVD and their relationship to subclinical CVD in this population iii) studies that have addressed these risk factors in order to improve CVD outcomes in children with T1DM RECENT FINDINGS: Subclinical CVD presents in children as increased carotid intima-media thickness, increased arterial stiffness, and endothelial and myocardial dysfunction. Modifiable risk factors for CVD include hyperglycemia, hyperlipidemia, obesity, hypertension, depression, and autonomic dysfunction. Very few randomized controlled studies have been done in children with T1DM to examine how modification of these risk factors can affect their CVD. Children with T1DM have subclinical CVD and multiple modifiable risk factors for CVD. More research is needed to define how modification of these factors affects the progression of CVD.

ACE Inhibitors and Statins in Adolescents with Type 1 Diabetes

BACKGROUND

Among adolescents with type 1 diabetes, rapid increases in albumin excretion during puberty precede the development of microalbuminuria and macroalbuminuria, long-term risk factors for renal and cardiovascular disease. We hypothesized that adolescents with high levels of albumin excretion might benefit from angiotensin-converting-enzyme (ACE) inhibitors and statins, drugs that have not been fully evaluated in adolescents.

METHODS

We screened 4407 adolescents with type 1 diabetes between the ages of 10 and 16 years of age and identified 1287 with values in the upper third of the albumin-to-creatinine ratios; 443 were randomly assigned in a placebo-controlled trial of an ACE inhibitor and a statin with the use of a 2-by-2 factorial design minimizing differences in baseline characteristics such as age, sex, and duration of diabetes. The primary outcome for both interventions was the change in albumin excretion, assessed according to the albumin-to-creatinine ratio calculated from three early-morning urine samples obtained every 6 months over 2 to 4 years, and expressed as the area under the curve. Key secondary outcomes included the development of microalbuminuria, progression of retinopathy, changes in the glomerular filtration rate, lipid levels, and measures of cardiovascular risk (carotid intima-media thickness and levels of high-sensitivity C-reactive protein and asymmetric dimethylarginine).

RESULTS

The primary outcome was not affected by ACE inhibitor therapy, statin therapy, or the combination of the two. The use of an ACE inhibitor was associated with a lower incidence of microalbuminuria than the use of placebo; in the context of negative findings for the primary outcome and statistical analysis plan, this lower incidence was not considered significant (hazard ratio, 0.57; 95% confidence interval, 0.35 to 0.94). Statin use resulted in significant reductions in total, low-density lipoprotein, and non-high-density lipoprotein cholesterol levels, in triglyceride levels, and in the ratio of apolipoprotein B to apolipoprotein A1, whereas neither drug had significant effects on carotid intima-media thickness, other cardiovascular markers, the glomerular filtration rate, or progression of retinopathy. Overall adherence to the drug regimen was 75%, and serious adverse events were similar across the groups.

CONCLUSIONS

The use of an ACE inhibitor and a statin did not change the albumin-to-creatinine ratio over time. (Funded by the Juvenile Diabetes Research Foundation and others; AdDIT ClinicalTrials.gov number, NCT01581476 .).

Relationship between serum inflammatory markers and vascular function in a cohort of adolescents with type 1 diabetes

OBJECTIVE

The contribution of inflammation to endothelial/vascular dysfunction in early Type I Diabetes (T1D) is not well understood. The objective of this study was to examine the interaction between systemic inflammation and vascular function in adolescent's with and without-T1D.

METHODS

51 subjects from our observational cohort of adolescents with T1D (JDRF-CCTN), and 59 healthy controls (HC) were studied. Serum cytokines-chemokines were quantified using Human 41-Plex Array, and vascular function was measured by Flow Mediated Dilatation (FMD), Pulse Wave Velocity (PWV) and Blood Pressure (BP). Factor Analysis was used to identify pro- and anti-inflammatory cytokine-chemokine factors, which were then correlated with vascular outcomes.

RESULTS

Three pro-inflammatory factors were identified in HC and three in TID, and a single anti-inflammatory factor in both groups. In HC there was a positive correlation (r=0.33; p=0.01) between control proinflammatory Factor 1 and systolic BP and a negative correlation between control proinflammatory Factor 3(r=-0.29; p=0.02) and diastolic BP. Control proinflammatory Factor 2 correlated positively with PWV. In TID subjects, no correlations were found between any of the pro-inflammatory factors and the vascular measurements. No correlations were found between the anti-inflammatory factors and BP, FMD and PWV in either HC or T1D. Levels of pro-inflammatory analytes, EGF, GRO, PDGF-BB, PDGF-AA and sCD40L were significantly higher in T1D.

CONCLUSIONS

The cytokine-chemokine signature in early T1D, prior to the development of arterial disease, is significantly different from that seen in healthy controls. This may be relevant to pathophysiology, determining risk and identifying target cytokines-chemokines for intervention in T1D.

Banting Memorial Lecture 2016 Reducing lifetime risk of complications in adolescents with Type 1 diabetes

Adolescence is a challenging period of life for any young person, and for those with Type 1 diabetes, physiological and psychological factors can result in a deterioration in glycaemic control. In young people with Type 1 diabetes, puberty may be an additional risk factor impacting on the lifetime risk for renal and cardiovascular complications. Our longitudinal studies have identified that increases in urinary albumin excretion through childhood are associated with the development of microalbuminuria and a generalized endotheliopathy linked to cardiovascular risk. Screening of participants recruited to the Adolescent type 1 Diabetes cardio-renal Intervention Trial (AdDIT) confirms that these early changes in albumin excretion are related to both diabetic nephropathy and cardiovascular risk; in part, independent of glycaemic control. Thus, as well as current attempts to improve glycaemic control through enhanced targeted insulin delivery, pumps, sensors and closed loop, we have explored the role of angiotensin-converting enzyme inhibitors and statins in providing cardio-renal protection during adolescence.

The relationship between urinary renin-angiotensin system markers, renal function, and blood pressure in adolescents with type 1 diabetes

The relationship between the renal renin-angiotensin aldosterone system (RAAS) and cardiorenal pathophysiology is unclear. Our aims were to assess 1) levels of urinary RAAS components and 2) the association between RAAS components and HbA1c, the urine albumin/creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), and blood pressure (BP) in otherwise healthy adolescents with type 1 diabetes mellitus (TID) vs. healthy controls (HC). Urinary angiotensinogen and angtionsin-converting enzyme (ACE) 2 levels, activity of ACE and ACE2, BP, HbA1c, ACR, and eGFR were measured in 65 HC and 194 T1D from the Adolescent Type 1 Diabetes Cardio-Renal Intervention Trial (AdDIT). Urinary levels of all RAAS components were higher in T1D vs. HC ( P < 0.0001). Higher HbA1c was associated with higher urinary angiotensinogen, ACE2, and higher activity of ACE and ACE2 ( P < 0.0001, P = 0.0003, P = 0.003, and P = 0.007 respectively) in T1D. Higher ACR (within the normal range) was associated with higher urinary angiotensinogen ( P < 0.0001) and ACE activity ( P = 0.007), but not with urinary ACE2 activity or ACE2 levels. These observations were absent in HC. Urinary RAAS components were not associated with BP or eGFR in T1D or HC. Otherwise healthy adolescents with T1D exhibit higher levels of urinary RAAS components compared with HC. While levels of all urinary RAAS components correlate with HbA1c in T1D, only urinary angiotensinogen and ACE activity correlate with ACR, suggesting that these factors reflect an intermediary pathogenic link between hyperglycemia and albuminuria within the normal range.

Incidence and Mortality Rates and Clinical Characteristics of Type 1 Diabetes among Children and Young Adults in Cochabamba, Bolivia

OBJECTIVES

To determine incidence, mortality, and clinical status of youth with diabetes at the Centro Vivir con Diabetes, Cochabamba, Bolivia, with support from International Diabetes Federation Life for a Child Program.

METHODS

Incidence/mortality data analysis of all cases (<25 year (y)) diagnosed January 2005-February 2017 and cross-sectional data (December 2015).

RESULTS

Over 12.2 years, 144 cases with type 1 diabetes (T1D) were diagnosed; 43.1% were male. Diagnosis age was 0.3-22.2 y; peak was 11-12 y. 11.1% were <5 y; 29.2%, 5-<10 y; 43.1%, 10-<15 y; 13.2%, 15-<20 y; and 3.5%, 20-<25 y. The youngest is being investigated for monogenic diabetes. Measured incidence in Cercado Province (Cochabamba Department) was 2.2/100,000 children < 15 y/y, with ≈80% ascertainment, giving total incidence of 2.7/100,000 children < 15 y/y. Two had died. Crude mortality rate was 2.3/1000 patient years. Clinical data on 141 cases <35 y: mean/median HbA1c was 8.5/8.2% (69/62 mmol/mol), levels higher in adolescents. Three were on renal replacement therapy; four others had substantial renal impairment. Elevated BMI, triglycerides, and cholesterol were common: 19.1%, 18.3%, and 39.1%, respectively.

CONCLUSIONS

Bolivia has low T1D incidence. Reasonable glycemic control is being achieved despite limited resources; however, some have serious complications and adverse cardiovascular risk factor profiles. Further attention is needed for complications.

Influence of HbA1c and BMI on Lipid Trajectories in Youths and Young Adults With Type 1 Diabetes

OBJECTIVE

To assess the influence of HbA1c and BMI (measured as BMI z score [zBMI]) on LDL, HDL, and non-HDL trajectories as youths with type 1 diabetes age into early adulthood.

RESEARCH DESIGN AND METHODS

Dynamic, retrospective cohort study examining changes in lipid values in 572 youths with type 1 diabetes followed longitudinally for a median of 9.3 years. Through longitudinal modeling, we describe the relationship of HbA1c and zBMI on lipid values as subjects age after adjusting for other relevant factors, including lipid-lowering medication use.

RESULTS

The median number of lipid assessments was 7 (range 2-39). Every 1% increase in HbA1c was associated with an ∼2-6 mg/dL increase in LDL levels, with a greater increase in LDL levels as subjects progressed from prepubertal to postpubertal age ranges. A 1-SD increase in BMI was associated with a mean LDL increase of 2.1 mg/dL when subjects were 10 years old and increased to a mean of 8.2 mg/dL when subjects were 19 years old. The association between changes in HbA1c level and zBMI and changes in non-HDL levels as youths aged were similar to the associations found with LDL. The influence of HbA1c and zBMI on HDL levels was small and not dependent on age.

CONCLUSIONS

Changes in HbA1c level and zBMI modestly impact LDL and non-HDL cholesterol and have greater impacts as children age. Addressing elevations in HbA1c and zBMI as children enter into adolescence and beyond may lead to improvements in lipid levels.

NGAL as an Early Predictive Marker of Diabetic Nephropathy in Children and Young Adults with Type 1 Diabetes Mellitus

AIMS

Type 1 diabetes (T1D) is often associated with early microvascular complications. Previous studies demonstrated that increased systolic (SAP) and diastolic arterial blood pressures (DAP) are linked to microvascular morbidity in T1D. The aim of the study was to investigate the predictive role of neutrophil gelatinase-associated lipocalin (NGAL) in unravelling early cardio-renal dysfunction in T1D.

METHODS

Two T1D patient groups participating in two-centre prospective cohorts were studied. Group A consisted of 57 participants aged 13.9 years (SD: 3.1) and group B consisted of 59 patients aged 28.0 years (SD: 4.4). Forty-nine healthy children [age: 10.5 years (SD: 6.6)] and 18 healthy adults [age 27.7 years (SD: 4.2)] served as controls. Serum concentrations of NGAL (ELISA) were determined, and SAP and DAP were examined (SAP and DAP also expressed as z-scores in the younger group).

RESULTS

NGAL correlated positively with SAP in both patient groups (P = 0.020 and P = 0.031, resp.) and SAP z-score (P = 0.009) (group A) and negatively with eGFR in both groups (P < 0.001 and P < 0.001, resp.).

CONCLUSIONS

NGAL may be proposed as a biomarker of early renal dysfunction even in nonalbuminuric T1D patients, since it was strongly associated with renal function decline and increasing systolic arterial pressure even at prehypertensive range in people with T1D, in a broad age range.

Social Determinants of Health Are Associated with Modifiable Risk Factors for Cardiovascular Disease and Vascular Function in Pediatric Type 1 Diabetes

OBJECTIVE

To evaluate the relationship between social determinants of health (SDH) and cardiovascular disease (CVD) risk factors as well as a measure of arterial stiffness in adolescents with type 1 diabetes (T1D).

STUDY DESIGN

SDH were measured with the validated Ontario Marginalization Index, derived from deidentified postal code data and stratified by quintile (first  = least deprived; fifth = most deprived). SDH dimensions included material deprivation; ethnic concentration; and measures of dependency and residential instability. Metabolic control (hemoglobin A1c), cardiovascular risk metrics, and pulse wave velocity, as a measure of arterial stiffness, were related to SDH. Data were evaluated from a cohort of Canadian adolescents within the Adolescent Diabetes Cardiorenal Intervention Trial, a T1D clinical trial

RESULTS

A total of 704 participants were evaluated, and significant differences in hemoglobin A1c were evident at the extremes of material deprivation (8.4% vs 9.1% for least vs most deprived, P < .01). CVD risk factors were analyzed in 199 participants, with the most deprived reporting significantly less exercise (P = .004) and increased rates of smoking (P = .008). Increased material deprivation was associated with fewer metrics of "ideal" cardiovascular health attained. Arterial stiffness, as measured by pulse wave velocity, was associated positively with age, body mass index z score, and material deprivation.

CONCLUSION

Increased material deprivation was associated with poorer glycemic control. Modifiable, lifestyle-related risk factors for CVD and early arterial wall change are associated with SDH and represent a target for clinical intervention to reduce future CVD burden in adolescents with T1D.

Cardiovascular medication use and cardiovascular disease in children and adolescents with type 1 diabetes: a population-based cohort study

OBJECTIVES

To investigate the 5-yr prevalence and incidence rates of cardiovascular medication and cardiovascular disease before and after onset of type 1 diabetes (T1D) in children and adolescents.

METHODS

Children and adolescents (<19 yr) with T1D (n = 925), defined as those who received at least two insulin prescriptions, and a four times larger reference cohort (n = 3591) with the same age and gender in the Dutch PHARMO Record Linkage System (RLS) were studied in a retrospective cohort study between 1999 and 2009. The date of first insulin dispensing was selected as the index date.

RESULTS

The overall prevalence rate of cardiovascular medication use was substantially higher in the T1D cohort before (2.2 vs. 1.0%, p < 0.001) and after (9.2 vs. 3.2%, p < 0.001) the index date. After the index date angiotensin-converting enzyme inhibitors (2.0%) and statins (1.5%) were the most prevalent cardiovascular medications in the T1D cohort. The highest incidence rate of cardiovascular medication use was observed in the first year after the index date [28.1 per 1000 person years (PY)]. Furthermore, three type 1 diabetic patients were hospitalized due to cardiomyopathy (n = 2) and heart failure (n = 1) and one child from the reference group was hospitalized due to cardiomyopathy in the 5 yr after the index date.

CONCLUSIONS

Children with T1D were more likely to use cardiovascular medications in the years before and after the onset of diabetes. Our study emphasizes the importance of routine screening tests and timely treatment of CVD risk factors in the pediatric population with diabetes.

Association Between Plasma Uric Acid Levels and Cardiorenal Function in Adolescents With Type 1 Diabetes

OBJECTIVE

The relationship between plasma uric acid (PUA) and renal and cardiovascular parameters in adolescents with type 1 diabetes (T1D) is not well understood. Our aims in this exploratory analysis were to study the association between PUA and estimated glomerular filtration rate (eGFR), urinary albumin-to-creatinine ratio (ACR), blood pressure, endothelial function, and arterial stiffness in T1D adolescents. These associations were also studied in healthy control (HC) subjects.

RESEARCH DESIGN AND METHODS

We studied 188 T1D subjects recruited to the Adolescent Type 1 Diabetes Cardio-Renal Intervention Trial (AdDIT) and 65 HC subjects. Baseline PUA, eGFRcystatin C, ACR, blood pressure, flow-mediated dilation (FMD), and carotid-femoral pulse wave velocity (PWV) were measured.

RESULTS

PUA was lower in T1D vs. HC subjects (242 ± 55 vs. 306 ± 74 μmol/L, respectively; P < 0.0001). Higher PUA was inversely associated with eGFR in T1D subjects (r = -0.48, P < 0.0001) even after correction for baseline clinical demographic characteristics. PUA was not associated with ACR in T1D after adjustment for potential confounders such as eGFR. For cardiovascular parameters, PUA levels did not associate with systolic blood pressure, FMD, or PWV in T1D or HC subjects.

CONCLUSIONS

Even within the physiological range, PUA levels were significantly lower in T1D adolescent patients compared with HC subjects. There was an inverse relationship between PUA and eGFR in T1D, likely reflecting an increase in clearance. There were no associations observed with ACR, blood pressure, arterial stiffness, or endothelial function. Thus, in contrast with adults, PUA may not yet be associated with cardiorenal abnormalities in adolescents with T1D.

Assessing social determinants of health in a pediatric diabetes clinical research trial: Are recruited subjects representative of the larger clinical population?

Social determinants of health (SDH) impact clinical outcomes and are often poorly described in research trials. Using a validated tool, SDH dimensions were compared between adolescents enrolled and not enrolled into a large diabetes study. We observed that our study cohort reflected a SDH profile mirroring the eligible population.

Early changes in cardiovascular structure and function in adolescents with type 1 diabetes

Background

Children with type 1 diabetes (T1D) are at higher risk of early adult-onset cardiovascular disease. We assessed cardiovascular structure and function in adolescents with T1D compared with healthy controls and the relationships between peripheral vascular function and myocardial parameters.

Methods and results

199 T1D [14.4 ± 1.6 years, diabetes duration 6.2 (2.0–12.8) years] and 178 controls (14.4 ± 2.1 years) completed endothelial function by flow mediated vasodilatation (FMD), arterial stiffness using pulse wave velocity (PWV) along with M-mode, pulse wave and tissue Doppler, and myocardial deformation echocardiographic imaging. Systolic (113 ± 10 vs. 110 ± 9 mmHg; p = 0.0005) and diastolic (62 ± 7 vs. 58 ± 7 mmHg; p < 0.0001) blood pressures, carotid femoral PWV and endothelial dysfunction measurements were increased in T1D compared with controls. Systolic and diastolic left ventricular dimensions and function by M-mode and pulse wave Doppler assessment were not significantly different. Mitral valve lateral e’ (17.6 ± 2.6 vs. 18.6 ± 2.6 cm/s; p < 0.001) and a’ (5.4 ± 1.1 vs. 5.9 ± 1.1 cm/s; p < 0.001) myocardial velocities were decreased and E/e’ (7.3 ± 1.2 vs. 6.7 ± 1.3; p = 0.0003) increased in T1D. Left ventricular mid circumferential strain (−20.4 ± 2.3 vs. −19.5 ± 1.7 %; p < 0.001) was higher, whereas global longitudinal strain was lower (−19.0 ± 1.9 vs. −19.8 ± 1.5 % p < 0.001) in T1D.

Conclusions

Adolescents with T1D exhibit early changes in blood pressure, peripheral vascular function and left ventricular myocardial deformation indices with a shift from longitudinal to circumferential shortening. Longitudinal follow-up of these changes in ongoing prospective trials may allow detection of those most at risk for cardiovascular abnormalities including hypertension that could preferentially benefit from early therapeutic interventions.

Challenges and Opportunities in the Management of Cardiovascular Risk Factors in Youth With Type 1 Diabetes: Lifestyle and Beyond

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in persons with type 1 diabetes (T1D). Specific risk factors associated with diabetes, such as hyperglycemia and kidney disease, have been demonstrated to increase the incidence and progression of CVD. Nevertheless, few data exist on the effects of traditional risk factors such as dyslipidemia, obesity, and hypertension on CVD risk in youth with T1D. Improvements in understanding and approaches to the evaluation and management of CVD risk factors, specifically for young persons with T1D, are desirable. Recent advances in noninvasive techniques to detect early vascular damage, such as the evaluation of endothelial dysfunction and aortic or carotid intima-media thickness, provide new tools to evaluate the progression of CVD in childhood. In the present review, current CVD risk factor management, challenges, and potential therapeutic interventions in youth with T1D are described.

Cardiac autonomic dysfunction is associated with high-risk albumin-to-creatinine ratio in young adolescents with type 1 diabetes in AdDIT (adolescent type 1 diabetes cardio-renal interventional trial)

OBJECTIVE

This study examined the association between cardiac autonomic dysfunction and high albumin-to-creatinine ratio (ACR) in adolescents with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Adolescents recruited as part of a multicenter screening study (n = 445, 49% female, aged 10-17 years, mean duration 6.9 years; mean HbA1c 8.4%, 68 mmol/mol) underwent a 10-min continuous electrocardiogram recording for heart rate variability analysis. Time-domain heart rate variability measures included baseline heart rate, SD of the R-R interval (SDNN), and root mean squared difference of successive R-R intervals (RMSSD). Spectral analysis included sympathetic (low-frequency) and parasympathetic (high-frequency) components. Standardized ACR were calculated from six early morning urine collections using an established algorithm, reflecting age, sex, and duration, and stratified into ACR tertiles, where the upper tertile reflects higher nephropathy risk.

RESULTS

The upper-tertile ACR group had a faster heart rate (76 vs. 73 bpm; P < 0.01) and less heart rate variability (SDNN 68 vs. 76 ms, P = 0.02; RMSSD 63 vs. 71 ms, P = 0.04). HbA1c was 8.5% (69 mmol/mmol) in the upper tertile vs. 8.3% (67 mmol/mol) in the lower tertiles (P = 0.07). In multivariable analysis, upper-tertile ACR was associated with faster heart rate (β = 2.5, 95% CI 0.2-4.8, P = 0.03) and lower RMSSD (β = -9.5, 95% CI -18.2 to -0.8, P = 0.03), independent of age and HbA1c.

CONCLUSIONS

Adolescents at potentially higher risk for nephropathy show an adverse cardiac autonomic profile, indicating sympathetic overdrive, compared with the lower-risk group. Longitudinal follow-up of this cohort will further characterize the relationship between autonomic and renal dysfunction and the effect of interventions in this population.

Blood pressure control for diabetic retinopathy

BACKGROUND

Diabetic retinopathy is a common complication of diabetes and a leading cause of visual impairment and blindness. Research has established the importance of blood glucose control to prevent development and progression of the ocular complications of diabetes. Simultaneous blood pressure control has been advocated for the same purpose, but findings reported from individual studies have supported varying conclusions regarding the ocular benefit of interventions on blood pressure.

OBJECTIVES

The primary aim of this review was to summarize the existing evidence regarding the effect of interventions to control or reduce blood pressure levels among diabetics on incidence and progression of diabetic retinopathy, preservation of visual acuity, adverse events, quality of life, and costs. A secondary aim was to compare classes of anti-hypertensive medications with respect to the same outcomes.

SEARCH METHODS

We searched a number of electronic databases including CENTRAL as well as ongoing trial registries. We last searched the electronic databases on 25 April 2014. We also reviewed reference lists of review articles and trial reports selected for inclusion. In addition, we contacted investigators of trials with potentially pertinent data.

SELECTION CRITERIA

We included in this review randomized controlled trials (RCTs) in which either type 1 or type 2 diabetic participants, with or without hypertension, were assigned randomly to intense versus less intense blood pressure control, to blood pressure control versus usual care or no intervention on blood pressure, or to different classes of anti-hypertensive agents versus placebo.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently reviewed titles and abstracts from electronic and manual searches and the full text of any document that appeared to be relevant. We assessed included trials independently for risk of bias with respect to outcomes reported in this review. We extracted data regarding trial characteristics, incidence and progression of retinopathy, visual acuity, quality of life, and cost-effectiveness at annual intervals after study entry whenever provided in published reports and other documents available from included trials.

MAIN RESULTS

We included 15 RCTs, conducted primarily in North America and Europe, that had enrolled 4157 type 1 and 9512 type 2 diabetic participants, ranging from 16 to 2130 participants in individual trials. In 10 of the 15 RCTs, one group of participants was assigned to one or more anti-hypertensive agents and the control group received placebo. In three trials, intense blood pressure control was compared to less intense blood pressure control. In the remaining two trials, blood pressure control was compared with usual care. Five of the 15 trials enrolled type 1 diabetics, and 10 trials enrolled type 2 diabetics. Six trials were sponsored entirely by pharmaceutical companies, seven trials received partial support from pharmaceutical companies, and two studies received support from government-sponsored grants and institutional support.Study designs, populations, interventions, and lengths of follow-up (range one to nine years) varied among the included trials. Overall, the quality of the evidence for individual outcomes was low to moderate. For the primary outcomes, incidence and progression of retinopathy, the quality of evidence was downgraded due to inconsistency and imprecision of estimates from individual studies and differing characteristics of participants.For primary outcomes among type 1 diabetics, one of the five trials reported incidence of retinopathy and one trial reported progression of retinopathy after 4 to 5 years of treatment and follow-up; four of the five trials reported a combined outcome of incidence and progression over the same time interval. Among type 2 diabetics, 5 of the 10 trials reported incidence of diabetic retinopathy and 3 trials reported progression of retinopathy; one of the 10 trials reported a combined outcome of incidence and progression during a 4- to 5-year follow-up period. One trial in which type 2 diabetics participated had reported no primary (or secondary) outcome targeted for this review.The evidence from these trials supported a benefit of more intensive blood pressure control intervention with respect to 4- to 5-year incidence of diabetic retinopathy (estimated risk ratio (RR) 0.80; 95% confidence interval (CI) 0.71 to 0.92) and the combined outcome of incidence and progression (estimated RR 0.78; 95% CI 0.63 to 0.97). The available evidence provided less support for a benefit with respect to 4- to 5-year progression of diabetic retinopathy (point estimate was closer to 1 than point estimates for incidence and combined incidence and progression, and the CI overlapped 1; estimated RR 0.88; 95% CI 0.73 to 1.05). The available evidence regarding progression to proliferative diabetic retinopathy or clinically significant macular edema or moderate to severe loss of best-corrected visual acuity did not support a benefit of intervention on blood pressure: estimated RRs and 95% CIs 0.95 (0.83 to 1.09) and 1.06 (0.85 to 1.33), respectively, after 4 to 5 years of follow-up. Findings within subgroups of trial participants (type 1 and type 2 diabetics; participants with normal blood pressure levels at baseline and those with elevated levels) were similar to overall findings.The adverse event reported most often (7 of 15 trials) was death, yielding an estimated RR 0.86 (95% CI 0.64 to 1.14). Hypotension was reported from three trials; the estimated RR was 2.08 (95% CI 1.68 to 2.57). Other adverse ocular events were reported from single trials.

AUTHORS' CONCLUSIONS

Hypertension is a well-known risk factor for several chronic conditions in which lowering blood pressure has proven to be beneficial. The available evidence supports a beneficial effect of intervention to reduce blood pressure with respect to preventing diabetic retinopathy for up to 4 to 5 years. However, the lack of evidence to support such intervention to slow progression of diabetic retinopathy or to prevent other outcomes considered in this review, along with the relatively modest support for the beneficial effect on incidence, weakens the conclusion regarding an overall benefit of intervening on blood pressure solely to prevent diabetic retinopathy.

The urinary cytokine/chemokine signature of renal hyperfiltration in adolescents with type 1 diabetes

OBJECTIVE

Urinary cytokine/chemokine levels are elevated in adults with type 1 diabetes (T1D) exhibiting renal hyperfiltration. Whether this observation extends to adolescents with T1D remains unknown. Our first objective was to determine the relationship between hyperfiltration and urinary cytokines/chemokines in normotensive, normoalbuminuric adolescents with T1D using GFR(cystatin). Our second aim was to determine the relationship between urine and plasma levels of inflammatory biomarkers, to clarify the origin of these factors.

METHODS

Urine and serum cytokines/chemokines (Luminex platform) and GFR(cystatin) were measured in normofiltering (n = 111, T1D-N, GFR<135 ml/min/1.73 m(2)) and hyperfiltering (n = 31, T1D-H, GFR ≥ 135 ml/min/1.73 m(2)) adolescents with T1D (ages 10-16), and in age and sex matched healthy control subjects (HC, n = 59).

RESULTS

We noted significant step-wise increases in urinary cytokine/chemokine excretion according to filtration status with highest levels in T1D-H, with parallel trends in serum analyte concentrations. After adjusting for serum glucose at the time of sampling, differences in urinary cytokine excretion were not statistically significant. Only serum IL-2 significantly differed between HC and T1D (p = 0.0076).

CONCLUSIONS

Hyperfiltration is associated with increased urinary cytokine/chemokine excretion in T1D adolescents, and parallel trends in serum cytokine concentration. The GFR-associated trends in cytokine excretion may be driven by the effects of ambient hyperglycemia. The relationship between hyperfiltration, glycemia, and variations in serum and urine cytokine expression and their impact on future renal and systemic vascular complications requires further study.

Early atherosclerosis relates to urinary albumin excretion and cardiovascular risk factors in adolescents with type 1 diabetes: Adolescent type 1 Diabetes cardio-renal Intervention Trial (AdDIT)

OBJECTIVE

The origins of cardiovascular and renal disease in type 1 diabetes begin during childhood. We aimed to evaluate carotid (cIMT) and aortic intima-media thickness (aIMT) and their relationship with cardiovascular risk factors and urinary albumin excretion in adolescents with type 1 diabetes in the Adolescent Type 1 Diabetes cardio-renal Intervention Trial (AdDIT).

RESEARCH DESIGN AND METHODS

A total of 406 adolescents with type 1 diabetes, who were 14.1 ± 1.9 years old with type 1 diabetes duration of 6.7 ± 3.7 years, and 57 age-matched control subjects provided clinical and biochemical data and ultrasound measurements of vascular structure (cIMT and aIMT). Vascular endothelial and smooth muscle function was also measured in 123 of 406 with type 1 diabetes and all control subjects.

RESULTS

In type 1 diabetic subjects, mean/maximal aIMT (P < 0.006; <0.008), but not mean/maximal cIMT, was greater than in control subjects. Mean/maximal aIMT related to urinary albumin-to-creatinine ratio (multiple regression coefficient [SE], 0.013 [0.006], P = 0.03; 0.023 [0.007], P = 0.002), LDL cholesterol (0.019 [0.008], P = 0.02; 0.025 [0.011], P = 0.02), and age (0.010 [0.004], P = 0.004; 0.012 [0.005], P = 0.01), independent of other variables. Mean/maximal cIMT was greater in males (0.023 [0.006], P = 0.02; 0.029 [0.007], P < 0.0001), and mean cIMT related independently to systolic blood pressure (0.001 [0.001], P = 0.04). Vascular smooth muscle function related to aIMT and cIMT but not to urinary albumin excretion.

CONCLUSIONS

aIMT may be a more sensitive marker of atherosclerosis than cIMT in type 1 diabetes during mid-adolescence. Higher urinary albumin excretion, even within the normal range, is associated with early atherosclerosis and should direct clinical attention to modifiable cardiovascular risk factors.

Update on screening, etiology, and treatment of dyslipidemia in children

CONTEXT

Cardiovascular disease is a leading cause of morbidity and mortality. Early identification and treatment of risk factors that accelerate this condition are paramount to preventing disease. To this effect, the National Heart Lung and Blood Institute (NHLBI), endorsed by the American Academy of Pediatrics, issued updated pediatric guidelines for cardiovascular risk reduction in 2011. Integration of these guidelines into pediatric practice may lessen cardiovascular morbidity.

EVIDENCE ACQUISITION

In addition to reviewing the NHLBI guidelines, a detailed literature search was performed on PubMed for clinical studies published between 2010 and 2013. Key search terms included "pediatric dyslipidemia/hyperlipidemia," "cardiovascular disease," "atherosclerosis," "familial hypercholesterolemia," "hypertriglyceridemia," and "diabetes." Additional citations from these publications were also reviewed. Final publications were selected for their relevance to the topic.

EVIDENCE SYNTHESIS

These guidelines contain several important recommendations relative to lipid management, including screening all children with nonfasting non-high-density lipoprotein-cholesterol at ages 9-11 years, incorporation of aggressive lifestyle changes to meet cholesterol targets, and initiation of statin therapy for those with low-density lipoprotein-cholesterol elevation. In addition, both type 1 and type 2 diabetes are now considered high-risk conditions and have stringent cholesterol targets. The primary aim is early identification of children with familial hypercholesterolemia; however, these recommendations have met with some controversy. The purpose of this update is to summarize these recent lipid guidelines, present the relevant controversies, highlight common cholesterol disorders, and discuss dyslipidemia specific to the pediatric diabetes population.

CONCLUSION

Identification and treatment of youth with dyslipidemia is of paramount importance to the reduction of future cardiovascular disease. Increasing the comprehension and application of the newest NHLBI guidelines is critical to improving cardiovascular outcomes.

Risks and benefits of statin use in young people with type 1 diabetes

Cardiovascular disease (CVD) is the primary cause of mortality in patients with type 1 diabetes (T1D). Despite advances in the management of microvascular complications of T1D, there is a lack of similar progress in reduction of macrovascular complications. Dyslipidemia is one of the major contributory factors for macrovascular complications in T1D, but the literature suggests significant under-treatment of this risk factor in children and adolescents with diabetes. Statins have shown to be both effective and safe in young people with familial hypercholesterolemia and adults with diabetes mellitus, but the role for statins in children and adolescent with T1D remains unclear and controversial. In this review, we will summarize the risks and benefits of statin use in young people with T1D.

Adolescent Type 1 Diabetes Cardio-Renal Intervention Trial (AdDIT): urinary screening and baseline biochemical and cardiovascular assessments

OBJECTIVE

We assessed the association between early increases in albumin excretion and cardiovascular (CV) and renal markers in a large cohort of young people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

As part of preliminary screening for a multicenter, randomized controlled trial of statins/ACE inhibitors, we measured albumin-creatinine ratio (ACR) in six early morning urine samples from 3,353 adolescents (10-16 years of age) and calculated tertiles based on an established algorithm. From those subjects deemed to be at higher risk (upper ACR tertile), we recruited 400 into the intervention study (trial cohort). From those subjects deemed to be at lower risk (middle-lower ACR tertiles), we recruited 329 to the observation cohort. At baseline, vascular measurements (carotid intima-media thickness, pulse wave velocity [PWV], flow-mediated dilatation, digital pulse amplitude tonometry), renal markers (symmetric dimethylarginine, cystatin C, creatinine), and CV disease markers (lipids and apolipoproteins [Apo] A-1 and B, C-reactive protein, asymmetric dimethylarginine) were assessed.

RESULTS

Age- and sex-adjusted PWV was higher in the trial than in the observational cohort (5.00 ± 0.84 vs. 4.86 ± 0.70 m/s; P = 0.021). Similarly, non-HDL cholesterol (2.95 ± 0.83 vs. 2.81 ± 0.78 mmol/L; P = 0.02) and ApoB-ApoA-1 ratio (0.50 ± 0.14 vs. 0.47 ± 0.11; P = 0.04) were higher in the trial cohort. Cystatin C and creatinine were decreased (0.88 ± 0.13 vs. 0.90 ± 0.13 mg/L, P = 0.04; 51.81 ± 10.45 vs. 55.35 ± 11.05 μmol/L, P < 0.001; respectively) and estimated glomerular filtration rate (137.05 ± 23.89 vs. 129.31 ± 22.41 mL/min/1.73 m(2); P < 0.001) increased in the trial compared with the observational cohort.

CONCLUSIONS

Our data demonstrate that in adolescents with type 1 diabetes, the group with the highest tertile of albumin excretion showed more evidence of early renal and CV disease than those in the lower tertiles.

Monitoring young people with type 1 diabetes for diabetic nephropathy: potential errors of annual ACR testing

AIM

Type 1 diabetes guidelines recommend annual monitoring of albumin-creatinine ratio (ACR) to detect nephropathy. Annual monitoring for conditions such as dyslipidemia leads to high rates of false-positive diagnoses. We estimated rates of false-positive and false-negative diagnoses under annual, biennial and triennial monitoring.

METHODS

Using Oxford Regional Prospective Study (ORPS) data we modelled ACR over time. Using simulation we estimated numbers of positive and negative diagnoses and the proportion that are false, over 6 years of monitoring, when assessment intervals are 1, 2 or 3 years.

RESULTS

Average increase per year (95%C.I.) in ACR was 3,5% (2,0-5,0%) for males and 4,8% (3,2-6,5%) for females. By 6 years, annual monitoring would lead to 56 (49-63) false-positive diagnoses for every 100 positive diagnoses of micro-albuminuria, biennial to 49 (42-57) false-positives and triennial to 46 (39-53). For every 100 negative diagnoses, annual monitoring would lead to 1,2 (0,8-1,5) false-negatives, biennial to 2,3 (1,7-3,0) and triennial to 3,0 (2,2-3,8).

CONCLUSION

Less frequent monitoring would result in fewer false-positive diagnoses, but increased false negatives, or missed diagnoses. The clinical implications of these scenarios need further investigation through cost-benefit analysis.

KDOQI Clinical Practice Guideline for Diabetes and CKD: 2012 Update

The 2012 update of the Kidney Disease Outcomes Quality Initiative (KDOQI) Clinical Practice Guideline for Diabetes and Chronic Kidney Disease (CKD) is intended to assist the practitioner caring for patients with diabetes and CKD. Substantial high-quality new evidence has emerged since the original 2007 KDOQI guideline that could significantly change recommendations for clinical practice. As such, revisions of prior guidelines are offered that specifically address hemoglobin A(1c) (HbA(1c)) targets, treatments to lower low-density lipoprotein cholesterol (LDL-C) levels, and use of angiotensin-converting enzyme inhibitor (ACE-I) and angiotensin receptor blocker (ARB) treatment in diabetic patients with and without albuminuria. Treatment approaches are addressed in each section and the stated guideline recommendations are based on systematic reviews of relevant trials. Appraisal of the quality of the evidence and the strength of recommendations followed the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Limitations of the evidence are discussed and specific suggestions are provided for future research.

Lessons learned from a lipid lowering trial in adolescents with type 1 diabetes

Herein, we describe recruitment efforts for a trial of lipid-lowering medications in adolescents with type 1 diabetes, age 12–21 years. Based on our experience, future studies will require multiple centers to enroll a sufficient number of participants for adequate data to direct dyslipidemia medication treatment guidelines for adolescents with type 1 diabetes.

Cardiovascular disease risk in young people with type 1 diabetes

Cardiovascular disease (CVD) is the most frequent cause of death in people with type 1 diabetes (T1D), despite modern advances in glycemic control and CVD risk factor modification. CVD risk identification is essential in this high-risk population, yet remains poorly understood. This review discusses the risk factors for CVD in young people with T1D, including hyperglycemia, traditional CVD risk factors (dyslipidemia, smoking, physical activity, hypertension), as well as novel risk factors such as insulin resistance, inflammation, and hypoglycemia. We present evidence that adverse changes in cardiovascular function, arterial compliance, and atherosclerosis are present even during adolescence in people with T1D, highlighting the need for earlier intervention. The methods for investigating cardiovascular risk are discussed and reviewed. Finally, we discuss the observational studies and clinical trials which have thus far attempted to elucidate the best targets for early intervention in order to reduce the burden of CVD in people with T1D.

Risk of cardiovascular disease and total mortality in adults with type 1 diabetes: Scottish registry linkage study

BACKGROUND

Randomized controlled trials have shown the importance of tight glucose control in type 1 diabetes (T1DM), but few recent studies have evaluated the risk of cardiovascular disease (CVD) and all-cause mortality among adults with T1DM. We evaluated these risks in adults with T1DM compared with the non-diabetic population in a nationwide study from Scotland and examined control of CVD risk factors in those with T1DM.

METHODS AND FINDINGS

The Scottish Care Information-Diabetes Collaboration database was used to identify all people registered with T1DM and aged ≥20 years in 2005-2007 and to provide risk factor data. Major CVD events and deaths were obtained from the national hospital admissions database and death register. The age-adjusted incidence rate ratio (IRR) for CVD and mortality in T1DM (n = 21,789) versus the non-diabetic population (3.96 million) was estimated using Poisson regression. The age-adjusted IRR for first CVD event associated with T1DM versus the non-diabetic population was higher in women (3.0: 95% CI 2.4-3.8, p<0.001) than men (2.3: 2.0-2.7, p<0.001) while the IRR for all-cause mortality associated with T1DM was comparable at 2.6 (2.2-3.0, p<0.001) in men and 2.7 (2.2-3.4, p<0.001) in women. Between 2005-2007, among individuals with T1DM, 34 of 123 deaths among 10,173 who were <40 years and 37 of 907 deaths among 12,739 who were ≥40 years had an underlying cause of death of coma or diabetic ketoacidosis. Among individuals 60-69 years, approximately three extra deaths per 100 per year occurred among men with T1DM (28.51/1,000 person years at risk), and two per 100 per year for women (17.99/1,000 person years at risk). 28% of those with T1DM were current smokers, 13% achieved target HbA(1c) of <7% and 37% had very poor (≥9%) glycaemic control. Among those aged ≥40, 37% had blood pressures above even conservative targets (≥140/90 mmHg) and 39% of those ≥40 years were not on a statin. Although many of these risk factors were comparable to those previously reported in other developed countries, CVD and mortality rates may not be generalizable to other countries. Limitations included lack of information on the specific insulin therapy used.

CONCLUSIONS

Although the relative risks for CVD and total mortality associated with T1DM in this population have declined relative to earlier studies, T1DM continues to be associated with higher CVD and death rates than the non-diabetic population. Risk factor management should be improved to further reduce risk but better treatment approaches for achieving good glycaemic control are badly needed. Please see later in the article for the Editors' Summary.

Microalbuminuria: causes and implications

Management strategies are increasingly focused on tackling the increasing burden of cardiovascular disease worldwide. Microalbuminuria is a powerful predictor of cardiovascular disease and mortality in adults. This holds true in the general adult population but is particularly recognized in those with diabetes, where it identifies those likely to develop progressive atherosclerotic vascular disease and renal impairment. The atherosclerotic process begins in childhood with likely consequences in later life. In-depth understanding of the mechanisms through which microalbuminuria occurs holds promise for designing therapies to arrest its development in the future. Microalbuminuria arises from increased leakage of albumin through the complex glomerular sieve known as the glomerular filtration barrier. This requires changes in the physio-chemical properties of components of this barrier. However, the increased glomerular permeability confirmed in disease does not necessarily correlate with recognized histological changes in the glomerulus, suggesting that perhaps more subtle ultrastructural changes may be relevant. The epidemiology of microalbuminuria reveals a close association between systemic endothelial dysfunction and vascular disease, also implicating glomerular endothelial dysfunction in microalbuminuria. This review discusses the mechanisms of microalbuminuria in disease, particularly the emerging role of the glomerular endothelium and its glycocalyx, and examines its implications for cardiovascular disease in the pediatric population.

Macrovascular angiopathy in children and adolescents with type 1 diabetes

Diabetes represents one of the most common diseases globally. Worryingly, the worldwide incidence of type 1 diabetes (T1D) is rising by 3% per year. Despite the rapid increase in diabetes incidence, recent advances in diabetes treatment have been successful in decreasing morbidity and mortality from diabetes-related retinopathy, nephropathy, and neuropathy. In contrast, there is clear evidence for the lack of improvement in mortality for cardiovascular diseases (CVDs). This emphasizes the importance of focusing childhood diabetes care strategies for the prevention of CVD in adulthood. Furthermore, although most work on diabetes and macrovascular disease relates to type 2 diabetes, it has been shown that the age-adjusted relative risk of CVD in T1D far exceeds that in type 2 diabetes. As T1D appears predominantly during childhood, those with T1D are at greater risk for coronary events early in life and require lifelong medical attention. Because of the important health effects of CVDs in children and adolescents with T1D, patients, family members, and care providers should understand the interaction of T1D and cardiovascular risk. In addition, optimal cardiac care for the patient with diabetes should focus on aggressive management of traditional cardiovascular risk factors to optimize those well-recognized as well as new specific risk factors which are becoming available. Therefore, a complete characterization of the molecular mechanisms involved in the development and progression of macrovascular angiopathy is needed. Furthermore, as vascular abnormalities begin as early as in childhood, potentially modifiable risk factors should be identified at an early stage of vascular disease development.

Considering statins for cholesterol-reduction in children if lifestyle and diet changes do not improve their health: a review of the risks and benefits

Children who appear healthy, even if they have one or more recognized cardiovascular risk factors, do not generally have outcomes of cardiovascular or other vascular disease during childhood. Historically, pediatric medicine has not aggressively screened for or treated cardiovascular risk factors in otherwise healthy children. However, studies such as the P-Day Study (Pathobiological Determinants of Atherosclerosis in Youth), and the Bogalusa Heart Study, indicate that healthy children at remarkably young ages can have evidence of significant atherosclerosis. With the increasing prevalence of pediatric obesity, can we expect more health problems related to the consequences of pediatric dyslipidemia, hypertriglyceridemia, and atherosclerosis in the future? For many years, medications have been available and used in adult populations to treat dyslipidemia. In recent years, reports of short-term safety of some of these medications in children have been published. However, none of these studies have detailed long-term follow-up, and therefore none have described potential late side-effects of early cholesterol-lowering therapy, or potential benefits in terms of reduction of or delay in cardiovascular or other vascular end-points. In 2007, the American Heart Association published a scientific statement on the use of cholesterol-lowering therapy in pediatric patients. In this review paper, we discuss some of the current literature on cholesterol-lowering therapy in children, including the statins that are currently available for use in children, and some of the cautions with using these and other cholesterol-lowering medications. A central tenet of this review is that medications are not a substitute for dietary and lifestyle interventions, and that even in children on cholesterol-lowering medications, physicians should take every opportunity to encourage children and their parents to make healthy diet and lifestyle choices.