Vascular function and glucose variability improve transiently following initiation of continuous subcutaneous insulin infusion in children with type 1 diabetes

Risk predictors of glycaemic control in children and adolescents with type 1 diabetes: A systematic review and meta-analysis

OBJECTIVES

To conduct systematic evaluation of the risk predictors of glycaemic control in children and adolescents with type 1 diabetes mellitus.

METHODS

Cohort studies on risk predictors of glycaemic control in children and adolescents with type 1 diabetes were retrieved from CNKI, PubMed, Web of Science, Embase databases, etc. from the construction of the repository to 3 February 2023. Literature screening was conducted according to inclusion and exclusion criteria, then data extraction of region, sample size, age, follow-up time, risk predictors, outcome indicators, etc., and quality evaluation of The Newcastle-Ottawa Scale were conducted by two researchers while the third researcher makes decisions if there are disagreements. Finally, Revman5.4 and StataMP17 were used for meta-analysis.

RESULTS

A total of 29 studies were included, and the results showed that insulin pump [Weighed mean difference (WMD) = -.48, 95% CI (-.73, -.24), p < .01], high-frequency sensor monitoring, early use of insulin pumps, prospective follow-up male, white race, large body mass index-standardised scoring, conscientiousness, agreeableness of mothers, eicosapentaenoic acid, leucine and protein (p < .05) were beneficial for reducing HbA1c levels in children and adolescents with diabetes. Ketoacidosis [WMD = .39, 95% CI (.28, .50), p < .01], selective admission, higher HbA1c level at one time (p < .01), higher glutamate decarboxylase antibody at 1 month after diagnosis, lower socio-economic status, non-living with biological parents, non-two-parent family, family disorder, family history of diabetes and high carbohydrate intake (p < .05) increased HbA1c levels in children and adolescents with diabetes.

CONCLUSION

For children and adolescents with type 1 diabetes mellitus, the use of insulin pump, high-frequency sensor monitoring, prospective follow-up, good family support and reasonable diet are conducive to blood glucose control, while selective admission and DKA are not. Disease characteristics and demographic characteristics of children are closely related to subsequent blood glucose control, and the relationship between diagnosis age and blood glucose control needs to be further explored.

Interventions to Decrease Carotid-Intima Media Thickness in Children and Adolescents With Type 1 Diabetes: A Systematic Review and Meta-Analysis

Introduction

Hyperglycemia is associated with a higher cardiovascular risk, as evidenced by increased carotid-intima media thickness (CIMT) in youth with diabetes. We conducted a systematic review and meta-analysis to assess the effect of pharmacological or non-pharmacological interventions on CIMT in children and adolescents with prediabetes or diabetes.

Methods

We conducted systematic searches of MEDLINE, EMBASE, and CENTRAL, together with supplementary searches in trial registers and other sources for studies completed up to September 2019. Interventional studies assessing ultrasound CIMT in children and adolescents with prediabetes or diabetes were considered for inclusion. Where appropriate, data were pooled across studies using random-effect meta-analysis. Quality was assessed using The Cochrane Collaboration's risk-of-bias tool and a CIMT reliability tool.

Results

Six studies involving 644 children with type 1 diabetes mellitus were included. No study involved children with prediabetes or type 2 diabetes. Three randomized controlled trials (RCTs) evaluated the effects of metformin, quinapril, and atorvastatin. Three non-randomized studies, with a before-and-after design, evaluated the effects of physical exercise and continuous subcutaneous insulin infusion (CSII). The mean CIMT at baseline ranged from 0.40 to 0.51 mm. The pooled difference in CIMT was -0.01 mm (95% CI: -0.04 to 0.01) for metformin compared to placebo (2 studies; 135 participants; I2: 0%). The difference in CIMT was -0.01 mm (95% CI: -0.03 to 0.01) for quinapril compared to placebo (1 study; 406 participants). The mean change from baseline in CIMT was -0.03 mm (95% CI: -0.14 to 0.08) after physical exercise (1 study; 7 participants). Inconsistent results were reported for CSII or for atorvastatin. CIMT measurement was rated at a higher quality on all reliability domains in 3 (50%) studies. The confidence in results is limited by the low number of RCTs and their small sample sizes, as well as the high risk of bias in before-and-after studies.

Conclusions

Some pharmacological interventions may decrease CIMT in children with type 1 diabetes. However, there is great uncertainty with respect to their effects and no strong conclusions can be drawn. Further evidence from larger RCTs is required.

Systematic Review Registration

PROSPERO, CRD42017075169.

Vascular and Myocardial Function in Young People with Type 1 Diabetes Mellitus: Insulin Pump Therapy Versus Multiple Daily Injections Insulin Regimen

INTRODUCTION

Multiple daily injections (MDI) and continuous subcutaneous insulin infusion (CSII) are two modalities of treating type 1 diabetes mellitus (T1DM). The benefits of CSII on long-term metabolic control and outcomes compared to those of MDI are still debated. We investigated both vascular function and myocardial performance in T1DM adolescents on MDI or CSII treatment.

METHODS

One hundred twenty-three T1DM subjects (mean age 14.16±2.55 years), 63 on MDI regimen, 60 on CSII, and 57 controls were enrolled. Anthropometric and biochemical characteristics were evaluated. Ultrasound assessments of carotid intima-media thickness (cIMT), flow-mediated dilatation of brachial artery, anteroposterior diameter of the infrarenal abdominal aorta (APAO), and transthoracic echocardiography were performed.

RESULTS

T1DM subjects on the CSII regimen showed better glycemic control than those on MDI, expressed as glycated haemoglobin (HbA1c). c-IMT and APAO were higher in MDI than CSII patients (0.61±0.11 mm vs. 0.56±0.07 mm, p=0.04; 13.61±3.29 mm vs. 11.65±1.84 mm, p=0.01, respectively). Left and right Tei index and left E/e' ratio were higher in MDI than CSII subjects (0.82±0.40 vs. 0.52±0.19, p=0.002; 0.86±0.41 vs. 0.64±0.1, p=0.02; 5.89±2.0 vs. 4.73±1.59, p=0.02, respectively). Multiple regression analyses showed that glucose level, HbA1c and diabetes onset were significantly related to vascular and echocardiographic parameters in MDI and CSII patients.

CONCLUSIONS

CSII regimen in T1DM adolescents improves glycemic control and seems to ameliorate endothelial function and global myocardial performance as compared to MDI therapy.

HbA1c variability in adults with type 1 diabetes on continuous subcutaneous insulin infusion (CSII) therapy compared to multiple daily injection (MDI) treatment

OBJECTIVE

To determine if continuous subcutaneous insulin infusion (CSII) therapy is associated with lower glycated haemoglobin (HbA1c) variability (long-term glycaemic variability; GV) relative to multiple daily injection (MDI) treatment in adults with type 1 diabetes mellitus (T1DM).

DESIGN

Retrospective audit.

SETTING AND PARTICIPANTS

Clinic records from 506 adults with T1DM from two tertiary Australian hospitals.

OUTCOME MEASURES

Long-term GV was assessed by HbA1c SD and coefficient of variation (CV) in adults on established MDI or CSII therapy, and in a subset changing from MDI to CSII.

RESULTS

Adults (n=506, (164 CSII), 50% women, mean±SD age 38.0±15.3 years, 17.0±13.7 years diabetes, mean HbA1c 7.8%±1.2% (62±13 mmol/mol) on CSII, 8.0%±1.5% (64±16 mmol/mol) on MDI) were followed for 4.1±3.6 years. CSII use was associated with lower GV (HbA1c SD: CSII vs MDI 0.5%±0.41% (6±6 mmol/mol) vs 0.7%±0.7% (9±8 mmol/mol)) and CV: CSII vs MDI 6.7%±4.6% (10±10 mmol/mol) vs 9.3%±7.3% (14±13 mmol/mol), both p<0.001. Fifty-six adults (73% female, age 36±13 years, 16±13 years diabetes, HbA1c 7.8%±0.8% (62±9 mmol/mol)) transitioned from MDI to CSII. Mean HbA1c fell by 0.4%. GV from 1 year post-CSII commencement decreased significantly, HbA1c SD pre-CSII versus post-CSII 0.7%±0.5% (8±5 mmol/mol) vs 0.4%±0.4% (5±4 mmol/mol); p<0.001, and HbA1c CV 9.2%±5.5% (13±8 mmol/mol) vs 6.1%±3.9% (9±5 mmol/mol); p<0.001.

CONCLUSIONS

In clinical practice with T1DM adults relative to MDI, CSII therapy is associated with lower HbA1c GV.

Continuous Subcutaneous Insulin Infusion Initiation Is Associated With Blood Pressure Reduction in Adults With Type 1 Diabetes

BACKGROUND

In type 1 diabetes (T1D) continuous subcutaneous insulin infusion (CSII) use has been associated with lower risks for mortality and diabetes-related complications when compared to multiple daily injections. There are limited data on the effect of CSII on blood pressure (BP). We aimed to evaluate the relationship between CSII initiation and BP changes.

METHODS

We performed a retrospective, single-center, observational study including all adults with T1D who initiated CSII between 2001 and 2014. Mean systolic BP levels were calculated from values obtained up to 15 months before and up 15 months after CSII initiation.

RESULTS

We studied 436 adults (46% male; mean [95% CI] age: 45 [36, 54] years, duration of diabetes: 20.3 [19.1, 21.5] years). CSII was associated with the following changes (post minus pre CSII levels) in mean (95% CI) SBP and DBP levels, respectively: whole cohort (N = 436): -2 (-1, -3), P < .001 and -2 (-1, -2), P < .001; those taking stable antihypertensive medication (n = 118): -4 (-6, -2), P < .001 and -2 (-3, -1), P < .001; antihypertensive treatment-naïve patients (n = 279): -1 (-2, 0), P = .147 and -1 (-2, 0), P = .002. In multivariate regression analysis including age, sex, diabetes duration, pre-CSII BP, HbA1c and weight changes, only pre-CSII BP showed an independent association with BP drop in all patients' groups. Once adjusted for pre-CSII BP there was no significant difference between those on antihypertensive drugs and antihypertensive treatment-naïve individuals.

CONCLUSIONS

We showed BP reduction in association with CSII therapy particularly in those on antihypertensive medication. These original findings may partly explain the cardiovascular and mortality benefits associated with CSII therapy.

Continuous subcutaneous insulin infusion versus multiple daily injections in children and young people at diagnosis of type 1 diabetes: the SCIPI RCT

BACKGROUND

The risk of developing long-term complications of type 1 diabetes (T1D) is related to glycaemic control and is reduced by the use of intensive insulin treatment regimens: multiple daily injections (MDI) (≥ 4) and continuous subcutaneous insulin infusion (CSII). Despite a lack of evidence that the more expensive treatment with CSII is superior to MDI, both treatments are used widely within the NHS.

OBJECTIVES

(1) To compare glycaemic control during treatment with CSII and MDI and (2) to determine safety and cost-effectiveness of the treatment, and quality of life (QoL) of the patients.

DESIGN

A pragmatic, open-label randomised controlled trial with an internal pilot and 12-month follow-up with 1 : 1 web-based block randomisation stratified by age and centre.

SETTING

Fifteen diabetes clinics in hospitals in England and Wales.

PARTICIPANTS

Patients aged 7 months to 15 years.

INTERVENTIONS

Continuous subsutaneous insulin infusion or MDI initiated within 14 days of diagnosis of T1D.

DATA SOURCES

Data were collected at baseline and at 3, 6, 9 and 12 months using paper forms and were entered centrally. Data from glucometers and CSII were downloaded. The Health Utilities Index Mark 2 was completed at each visit and the Pediatric Quality of Life Inventory (PedsQL, diabetes module) was completed at 6 and 12 months. Costs were estimated from hospital patient administration system data.

OUTCOMES

The primary outcome was glycosylated haemoglobin (HbA_1c) concentration at 12 months. The secondary outcomes were (1) HbA_1c concentrations of < 48 mmol/mol, (2) severe hypoglycaemia, (3) diabetic ketoacidosis (DKA), (4) T1D- or treatment-related adverse events (AEs), (5) change in body mass index and height standard deviation score, (6) insulin requirements, (7) QoL and (8) partial remission rate. The economic outcome was the incremental cost per quality-adjusted life-year (QALY) gained.

RESULTS

A total of 293 participants, with a median age of 9.8 years (minimum 0.7 years, maximum 16 years), were randomised (CSII, n = 149; MDI, n = 144) between May 2011 and January 2015. Primary outcome data were available for 97% of participants (CSII, n = 143; MDI, n = 142). At 12 months, age-adjusted least mean squares HbA_1c concentrations were comparable between groups: CSII, 60.9 mmol/mol [95% confidence interval (CI) 58.5 to 63.3 mmol/mol]; MDI, 58.5 mmol/mol (95% CI 56.1 to 60.9 mmol/mol); and the difference of CSII - MDI, 2.4 mmol/mol (95% CI -0.4 to 5.3 mmol/mol). For HbA_1c concentrations of < 48 mmol/mol (CSII, 22/143 participants; MDI, 29/142 participants), the relative risk was 0.75 (95% CI 0.46 to 1.25), and for partial remission rates (CSII, 21/86 participants; MDI, 21/64), the relative risk was 0.74 (95% CI 0.45 to 1.24). The incidences of severe hypoglycaemia (CSII, 6/144; MDI, 2/149 participants) and DKA (CSII, 2/144 participants; MDI, 0/149 participants) were low. In total, 68 AEs (14 serious) were reported during CSII treatment and 25 AEs (eight serious) were reported during MDI treatment. Growth outcomes did not differ. The reported insulin use was higher with CSII (mean difference 0.1 unit/kg/day, 95% CI 0.0 to 0.2 unit/kg/day; p = 0.01). QoL was slightly higher for those randomised to CSII. From a NHS perspective, CSII was more expensive than MDI mean total cost (£1863, 95% CI £1620 to £2137) with no additional QALY gains (-0.006 QALYs, 95% CI -0.031 to 0.018 QALYs).

LIMITATIONS

Generalisability beyond 12 months is uncertain.

CONCLUSIONS

No clinical benefit of CSII over MDI was identified. CSII is not a cost-effective treatment in patients representative of the study population.

FUTURE WORK

Longer-term follow-up is required to determine if clinical outcomes diverge after 1 year. A qualitative exploration of patient and professional experiences of MDI and CSII should be considered.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN29255275 and EudraCT 2010-023792-25.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 42. See the NIHR Journals Library website for further project information. The cost of insulin pumps and consumables supplied by F. Hoffman-La Roche AG (Basel, Switzerland) for the purpose of the study were subject to a 25% discount on standard NHS costs.

Influence of initial insulin dosage on blood glucose dynamics of children and adolescents with newly diagnosed type 1 diabetes mellitus

OBJECTIVE

To investigate the effect of initial insulin dosage on blood glucose (BG) dynamics, β-cell protection, and oxidative stress in type 1 diabetes mellitus.

METHODS

Sixty newly diagnosed type 1 diabetes mellitus patients were randomly assigned to continuous subcutaneous insulin infusions of 0.6 ± 0.2 IU/kg/d (group 1), 1.0 ± 0.2 IU/kg/d (group 2), or 1.4 ± 0.2 IU/kg/d (group 3) for 3 wk. BG was monitored continuously for the first 10 d and the last 2 d of wk 2 and 3. A total of 24-hour urinary 8-iso-PGF2α was assayed on days 8, 9, and 10. The occurrence and duration of the honeymoon period were recorded. Fasting C-peptide and glycosylated hemoglobin (HbA1c) were assayed after 1, 6, and 12 months of insulin treatment.

RESULTS

BG decreased to the target range by the end of wk 3 (group 1), wk 2 (group 2), or wk 1 (group 3). The actual insulin dosage over the 3 wk, frequency of hypoglycemia on wk 1 and 2, and median BG at the end of wk 1 differed significantly, but not 8-iso-PGF2α and the honeymoon period in the three groups. No severe hypoglycemia event was observed in any patient, but there was significant difference in the first occurrence of hypoglycemia.

CONCLUSIONS

Differences in initial insulin dosage produced different BG dynamics in wk 1, equivalent BG dynamics on wk 2 and 3, but had no influence on short- and long-term BG control and honeymoon phase. The wide range of initial insulin dosage could be chosen if guided by BG monitoring.

The role of insulin pump therapy for type 2 diabetes mellitus

Many patients with type 2 diabetes fail to achieve adequate glucose control despite escalation of treatment and combinations of multiple therapies including insulin. Patients with long-standing type 2 diabetes often suffer from the combination of severe insulin deficiency in addition to insulin resistance, thereby requiring high doses of insulin delivered in multiple injections to attain adequate glycemic control. Insulin-pump therapy was first introduced in the 1970s as an approach to mimic physiological insulin delivery and attain normal glucose in patients with type 1 diabetes. The recent years have seen an increase in the use of this technology for patients with type 2 diabetes. This article summarizes the clinical studies evaluating insulin pump use in patients with type 2 diabetes and discusses the benefits and shortcomings of pump therapy in this population. Copyright © 2016 John Wiley & Sons, Ltd.

Glycemic Variability Is Associated with Markers of Vascular Stress in Adolescents

OBJECTIVES

We used continuous glucose monitoring to test the hypothesis that mean amplitude of glycemic excursions (MAGE) is associated with circulating markers of oxidative and vascular stress in adolescents with habitually low physical activity classified as healthy weight, healthy obese, or obese with type 2 diabetes mellitus (T2DM).

STUDY DESIGN

A group of 13- to 21-year-olds (healthy weight = 12, healthy obese = 10, T2DM = 12) wore a continuous glucose monitor and step activity monitor for 5 days.

RESULTS

Physical activity was similar among groups (6551 ± 401 steps/d), but aerobic fitness (peak rate of oxygen consumption) was lower (P < .05) in T2DM (15.6 ± 1.8 mL/kg/min) than either healthy weight (26.2 ± 2.2) or healthy obese (24.4 ± 2.5). MAGE (mg/dL) was higher (P < .01) in T2DM (82 ± 10) vs healthy obese (33 ± 3) and healthy weight (30 ± 3). Average glucose followed a similar pattern as MAGE. Oxidized low density lipoprotein was higher (P < .05) in T2DM (70.3 ± 5.0 U/L) and healthy obese (58.1 ± 3.8) than healthy weight (48.4 ± 2) and positively correlated with MAGE (r = 0.77). Other stress markers that were both elevated in T2DM and correlated with MAGE included E-selectin (r = 0.50), intercellular adhesion molecule 1 (r = 0.35), and C-reactive protein (r = 0.52); soluble receptor for advanced glycosylation end product was lower in T2DM and inversely correlated with MAGE (r = -0.38).

CONCLUSIONS

MAGE is highest in obese youth with T2DM. The associations between MAGE and oxidative stress markers support the proposed contribution of glycemic variability to risk for future cardiovascular disease.

Impact of Real-Time Continuous Glucose Monitoring Use on Glucose Variability and Endothelial Function in Adolescents with Type 1 Diabetes: New Technology--New Possibility to Decrease Cardiovascular Risk?

Children with type 1 diabetes (T1DM) are the high-risk group of accelerated atherosclerosis. Real-time continuous glucose monitoring (RT-CGM) provides possibilities for the detection of glycaemic variability, newly recognized cardiovascular risk factor. The aim of the study was to assess the usefulness of RT-CGM as an educational tool to find and reduce glycaemic variability in order to improve endothelial function in T1DM adolescents. Forty patients aged 14.6 years were recruited. The study was based on one-month CGM sensors use. Parameters of glycaemic variability were analyzed during first and last sensor use, together with brachial artery flow-mediated dilatation (FMD) to assess endothelial function. In the whole group, FMD improvement was found (10.9% to 16.6%, p < 0.005), together with decrease in all studied glycaemic variability parameters. In patients with HbA1c improvement compared to the group without HbA1c improvement, we found greater increase of FMD (12% to 19%, p < 0.005 versus 8.2% to 11.3%, p = 0.080) and greater improvement of glucose variability. RT-CGM can be considered as an additional tool that offers T1DM adolescents the quick reaction to decrease glycaemic variability in short time observation. Whether such approach might influence improvement in endothelial function and reduction of the risk of future cardiovascular disease remains to be elucidated.

The Impact of Insulin Pump Therapy on Glycemic Profiles in Patients with Type 2 Diabetes: Data from the OpT2mise Study

BACKGROUND

The OpT2mise randomized trial was designed to compare the effects of continuous subcutaneous insulin infusion (CSII) and multiple daily injections (MDI) on glucose profiles in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Patients with glycated hemoglobin (HbA1c) levels of ≥8% (64 mmol/mol) and ≤12% (108 mmol/mol) despite insulin doses of 0.7-1.8 U/kg/day via MDI were randomized to CSII (n=168) or continued MDI (n=163). Changes in glucose profiles were evaluated using continuous glucose monitoring data collected over 6-day periods before and 6 months after randomization.

RESULTS

After 6 months, reductions in HbA1c levels were significantly greater with CSII (-1.1±1.2% [-12.0±13.1 mmol/mol]) than with MDI (-0.4±1.1% [-4.4±12.0 mmol/mol]) (P<0.001). Similarly, compared with patients receiving MDI, those receiving CSII showed significantly greater reductions in 24-h mean sensor glucose (SG) (treatment difference, -17.1 mg/dL; P=0.0023), less exposure to SG >180 mg/dL (-12.4%; P=0.0004) and SG >250 mg/dL (-5.5%; P=0.0153), and more time in the SG range of 70-180 mg/dL (12.3%; P=0.0002), with no differences in exposure to SG<70 mg/dL or in glucose variability. Changes in postprandial (4-h) glucose area under the curve >180 mg/dL were significantly greater with CSII than with MDI after breakfast (-775.9±1,441.2 mg/dL/min vs. -160.7±1,074.1 mg/dL/min; P=0.0015) and after dinner (-731.4±1,580.7 mg/dL/min vs. -71.1±1,083.5 mg/dL/min; P=0.0014).

CONCLUSIONS

In patients with suboptimally controlled type 2 diabetes, CSII significantly improves selected glucometrics, compared with MDI, without increasing the risk of hypoglycemia.

Featured Article: Oxidative stress status and liver tissue defenses in diabetic rats during intensive subcutaneous insulin therapy

Long-term insulin delivery can reduce blood glucose variability in diabetic patients. In this study, its impact on oxidative stress status, inflammation, and liver injury was investigated. Diabetes was induced in Wistar rats with a single dose of streptozotocin (100 mg/kg). Untreated rats and rats administered Insuplant® (2 UI/200 g/day) through a subcutaneous osmotic pump for one or four weeks were compared with non-diabetic controls. Body weight, fructosamine level, total cholesterol, Insulin Growth Factor-1 (IGF-1) level, lipid peroxidation, and total antioxidant capacity were measured. Hepatic injury was determined through the measurement of glycogen content, reactive oxygen species (ROS) production, and macrophage infiltration. Liver oxidative stress status was evaluated through the measurement of superoxide dismutase (SOD), catalase (CAT), and nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase) expression, and p38 mitogen-activated protein kinase (p38MAPK) activation. Induction of diabetes led to increased plasma oxidative stress and inflammation. Moreover, ROS production and macrophage infiltration increased in addition to SOD, CAT, and NADPH oxidase expression. Intensive insulin therapy improved metabolic control in diabetic animals as seen by a restoration of hepatic glycogen, plasma IGF-1 levels, and a decrease in plasma oxidative stress. However, insulin treatment did not result in a decrease in acute inflammation in diabetic rats as seen by continued ROS production and macrophage infiltration in the liver, and a decrease of p38MAPK activation. These results suggest that the onset of diabetes induces liver oxidative stress and inflammation, and that subcutaneous insulin administration cannot completely reverse these changes. Targeting oxidative stress and/or inflammation in diabetic patients could be an interesting strategy to improve therapeutic options.

Adolescents and young adults with type 1 diabetes display a high prevalence of endothelial dysfunction

AIM

Little is known about endothelial function in adolescents with type 1 diabetes, and we evaluated endothelial dysfunction, using reactive hyperaemia peripheral arterial tonometry (RH-PAT).

METHODS

This prospective, observational, 1-year study focused on 73 adolescents with type 1 diabetes, using multiple daily injections or continuous subcutaneous insulin infusion. The subjects were assessed using RH-PAT, body mass index, blood pressure, fasting lipid profile, glycated haemoglobin, insulin requirements and hours of physical exercise per week.

RESULTS

Endothelial dysfunction was observed in 56 patients (76.7%), with lower mean RH-PAT scores (1.26 ± 0.22 versus 2.24 ± 0.48, p < 0.0001) and higher glycated haemoglobin values at baseline (8.27 ± 1.24% versus 7.37 ± 0.54%, p = 0.006) and as a mean of the whole period since diagnosis (8.25 ± 1.22% versus 7.72 ± 0.82%, p = 0.034). A higher percentage of patients with endothelial dysfunction showed abnormal cardiac autonomic tests (p = 0.02) and were more sedentary, exercising <4 hours a week, than patients with normal endothelial function. After follow-up in 64/73 patients, we observed endothelial dysfunction in 81.8% of patients, despite a modest improvement in glycated haemoglobin.

CONCLUSION

Adolescents with type 1 diabetes displayed evidence of endothelial dysfunction. Good metabolic control (glycated haemoglobin ≤7.5%, 58 mmol/mol) and regular physical activity of at least 4 h a week might be protective.

Does metformin improve vascular health in children with type 1 diabetes? Protocol for a one year, double blind, randomised, placebo controlled trial

BACKGROUND

Cardiovascular disease is the leading cause of mortality in Type 1 diabetes (T1D). Vascular dysfunction is an early and critical event in the development of cardiovascular disease. Children with T1D have vascular dysfunction therefore early interventions to improve vascular health are essential to reduce cardiovascular mortality in T1D. Metformin is an insulin sensitising agent which is known to improve vascular health outcomes in type 2 diabetes (T2D) and other individuals with insulin resistance. It has been used safely in children and adolescents with T2D for over 10 years. This study aims to assess the effect of metformin on vascular health in children with T1D.

METHODS/DESIGN

This study is a 12 month, double blind, randomised, placebo controlled trial to determine the effect of metformin on vascular health in children (age 8-18) with T1D. The sample size is 76 with 38 children in the metformin group and 38 children in the placebo group. Vascular health and biochemical markers will be measured at baseline, 3, 6 and 12 months. Vascular function will be measured using flow mediated dilatation and glyceryl trinitrate mediated dilatation of the brachial artery and vascular structure will be measured with carotid and aortic intima media thickness, using standardised protocols.

DISCUSSION

This study will be the first to investigate the effect of metformin on vascular health in children with T1D. It will provide important information on a potential intervention to improve cardiovascular morbidity and mortality in this population at high risk from cardiovascular disease.

TRIAL REGISTRATION

Australia New Zealand Clinical Trials Registry ACTRN12611000148976.