Comparison of human regular and lispro insulins after interruption of continuous subcutaneous insulin infusion and in the treatment of acutely decompensated IDDM

Ultra rapid lispro (Lyumjev®) shortens time to recovery from hyperglycaemia compared to Humalog® in individuals with type 1 diabetes on continuous subcutaneous insulin infusion

AIMS

To compare the time to hyperglycaemia recovery after ultra rapid lispro (URLi; Lyumjev®) versus Humalog in a randomized, double-blind crossover study.

MATERIALS AND METHODS

Thirty-two adults with type 1 diabetes on continuous subcutaneous insulin infusion participated in two periods: each period included hyperglycaemia induced by a missed mealtime bolus (day 1) and by suspension of basal insulin delivery (day 2). When hyperglycaemia [plasma glucose (PG) >240 mg/dl] occurred, a correction bolus of URLi or Humalog was given and time to hyperglycaemia recovery (PG = 140 mg/dl), pharmacokinetics and glucodynamics were compared.

RESULTS

Following a missed mealtime bolus, URLi significantly reduced maximum PG (-13 mg/dl; p = .02), and produced numerically more rapid decline in PG (23 mg/dl/h; p = .07), and faster recovery from hyperglycaemia (-23 min; p = .1) versus Humalog, although differences were not significant. Following basal suspension, URLi significantly reduced maximum PG (-6 mg/dl; p = .02), and produced faster PG decline (24 mg/dl/h; p < .001) and faster recovery from hyperglycaemia (-16 min; p < .01) vs. Humalog. Following a correction bolus of URLi, accelerated insulin lispro absorption was observed versus Humalog: early 50% tmax was reduced by 6 or 12 min, and AUC0-15min was increased 2.5- or 4.3-fold after correction boluses by subcutaneous infusion (day 1) or injection (day 2), respectively (all p < .001).

CONCLUSIONS

During episodes of hyperglycaemia commonly experienced in people with type 1 diabetes, URLi provided a faster recovery versus Humalog from a missed mealtime bolus or during basal insulin suspension. URLi shows significant acceleration of insulin absorption versus Humalog when boluses are administered by subcutaneous infusion or injection.

Ketone-Based Alert System for Insulin Pump Failures

BACKGROUND

An increasing number of individuals with type 1 diabetes (T1D) manage glycemia with insulin pumps containing short-acting insulin. If insulin delivery is interrupted for even a few hours due to pump or infusion site malfunction, the resulting insulin deficiency can rapidly initiate ketogenesis and diabetic ketoacidosis (DKA).

METHODS

To detect an event of accidental cessation of insulin delivery, we propose the design of ketone-based alert system (K-AS). This system relies on an extended Kalman filter based on plasma 3-beta-hydroxybutyrate (BOHB) measurements to estimate the disturbance acting on the insulin infusion/injection input. The alert system is based on a novel physiological model capable of simulating the ketone body turnover in response to a change in plasma insulin levels. Simulated plasma BOHB levels were compared with plasma BOHB levels available in the literature. We evaluated the performance of the K-AS on 10 in silico subjects using the S2014 UVA/Padova simulator for two different scenarios.

RESULTS

The K-AS achieves an average detection time of 84 and 55.5 minutes in fasting and postprandial conditions, respectively, which compares favorably and improves against a detection time of 193 and 120 minutes, respectively, based on the current guidelines.

CONCLUSIONS

The K-AS leverages the rapid rate of increase of plasma BOHB to achieve short detection time in order to prevent BOHB levels from rising to dangerous levels, without any false-positive alarms. Moreover, the proposed novel insulin-BOHB model will allow us to understand the efficacy of treatment without compromising patient safety.

Air occlusion in insulin pumps of children and adolescents with type 1 diabetes

Background Insulin pumps are a frequently used technology among youth with type 1 diabetes. Air bubbles within insulin pump tubing are common, preventing insulin delivery and increasing the risk of large glycemic excursions and diabetic ketoacidosis (DKA). We sought to determine the prevalence of air bubbles in insulin pump tubing and identify factors associated with clinically significant air bubbles. Methods Fifty-three subjects were recruited over 65 office visits. The insulin pump tubing was visualized, and any air bubbles were measured by length. The length of air bubbles was then converted to time without insulin at the lowest basal rate. Generalized linear model (GLM) was used to determine the associations between air bubble size and other variables. Results Of the 65 encounters, 45 had air bubbles in the tubing. Five (5/65 = 7.7%) encounters had a time without insulin of more than 60 min. Air bubble size was inversely correlated with time since infusion set change (p < 0.001), and directly correlated with age of the subject (p = 0.049). Conclusions Significantly more air bubbles were found in the tubing of insulin pumps soon after infusion set change and with older subjects, suggesting a relationship with the technique of filling the insulin cartridge and priming the tubing.

[Insulin pump therapy in children, adolescents and adults, guidelines (Update 2019)]

This position statement is based on current evidence available on the safety and benefits of continuous subcutaneous insulin infusion therapy (CSII, pump therapy) in diabetes with an emphasis on the effects of CSII on glycemic control, hypoglycaemia rates, occurrence of ketoacidosis, quality of life and the use of insulin pump therapy in pregnancy. The current article represents the recommendations of the Austrian Diabetes Association for the clinical praxis of insulin pump treatment in children, adolescents and adults.

The Clinical Case for the Integration of a Ketone Sensor as Part of a Closed Loop Insulin Pump System

Closed loop (CL) systems deliver insulin with a rapid onset and offset in action. Although favorable overall, the absence of a long-acting insulin increases the risk of diabetic ketoacidosis (DKA) which can occur with insulin delivery failure, acute illness, low carbohydrate diets, sodium glucose-linked transporter inhibitors, and high intensity exercise. A CL system relying entirely on interstitial glucose measurements may not provide an alert for DKA and many people with type 1 diabetes (T1D) do not carry a blood ketone meter and test-strips. Ketone sensing is theoretically feasible. A multianalyte platform incorporating a ketone sensor could provide an additional CL input without an increase in burden for the person with T1D, warning of impending DKA to allow remedial action to be taken. We outline the clinical case for inclusion of continuous ketone sensing as part of future CL systems.

Adjusting Insulin Delivery to Activity (AIDA) clinical trial: Effects of activity-based insulin profiles on glucose control in children with type 1 diabetes

BACKGROUND

Increased daytime activity in children with type I diabetes mellitus (T1DM) is associated with increased risk of hypoglycemia.

OBJECTIVE

To determine whether an automated weekly review of accelerometer, continuous glucose monitoring (CGM), and insulin pump data, could be used to identify children with increased risk of nighttime hypoglycemia and preemptively adjust the nighttime basal insulin profile according to daytime activity.

RESEARCH AND DESIGN METHODS

Clinical trial of children with T1DM on insulin pump and CGM therapy. Subjects at risk of nighttime hypoglycemia were identified from regression analysis of daytime step count vs nighttime nadir glucose. If the regression slope was significantly different from zero (P < 0.05) subjects were managed with different algorithm derived nighttime basal insulin profiles following high and low activity days.

RESULTS

Twenty children (median age: 12; range: 7-17 years) were enrolled. Regression slopes were significant in 10 children. In these children, baseline nighttime nadir glucose level was lower following high activity days (120 [110-139] vs 152 [130-162] mg/dL, P = 0.004). Use of activity-based nighttime basal profiles produced similar nighttime nadir glucose levels following high and low activity days (136 [123-175] vs 140 [108-180] mg/dL, P = 0.73) with fewer nighttime interventions to correct hypoglycemia (0 [0-0.16] vs 0.15 [0.13-0.22] per night, P = 0.008).

CONCLUSION

Children with lower nighttime glucose levels following high daytime activity can be identified using step count data obtained from readily available accelerometers and the nighttime glucose control improved using different activity-based basal profiles.

Sliding scale insulin for non-critically ill hospitalised adults with diabetes mellitus

BACKGROUND

Diabetes mellitus is a metabolic disorder resulting from a defect in insulin secretion, function, or both. Hyperglycaemia in non-critically ill hospitalised people is associated with poor clinical outcomes (infections, prolonged hospital stay, poor wound healing, higher morbidity and mortality). In the hospital setting people diagnosed with diabetes receive insulin therapy as part of their treatment in order to achieve metabolic control. However, insulin therapy can be provided by different strategies (sliding scale insulin (SSI), basal-bolus insulin, and other modalities). Sliding scale insulin is currently the most commonly used method, however there is uncertainty about which strategy provides the best patient outcomes.

OBJECTIVES

To assess the effects of SSI for non-critically ill hospitalised adults with diabetes mellitus.

SEARCH METHODS

We identified eligible trials by searching MEDLINE, Embase, LILACS, and the Cochrane Library. We searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov trial registers. The date of the last search for all databases was December 2017. We also examined reference lists of identified randomised controlled trials (RCTs) and systematic reviews, and contacted trial authors.

SELECTION CRITERIA

We included RCTs comparing SSI with other strategies for glycaemic control in non-critically ill hospitalised adult participants of any sex with diabetes mellitus.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data, assessed trials for risk of bias, and evaluated the overall certainty of evidence utilising the GRADE instrument. We synthesised data using a random-effects model meta-analysis with 95% prediction intervals, if possible, or descriptive analysis, as appropriate.

MAIN RESULTS

Of 720 records screened, we included eight trials that randomised 1048 participants with type 2 diabetes (387 SSI participants and 615 participants in comparator groups were available for final analysis). We included non-critically ill medical and surgical adults with the diagnosis of diabetes mellitus. The mean follow-up time was measured by the mean length of hospital stay and ranged between five and 24 days. The mean age of participants was 44.5 years to 71 years.Overall, we judged the risk of bias on the trial level as unclear for selection bias, high for outcome-related performance and detection bias with regard to hypoglycaemic episodes, other adverse events, and mean glucose levels, and low for all-cause mortality and length of hospital stay. Attrition bias was low for all outcome measures.Six trials compared SSI with a basal-bolus insulin scheme, three of which investigating 64% of all participants in this category also applying an SSI approach in the bolus comparator part. One trial had a basal insulin-only comparator arm, and the remaining trial used continuous insulin infusion as the comparator. For our main comparison of SSI versus basal-bolus insulin, the results were as follows. Four trials reported mortality data. One out of 268 participants in the SSI group (0.3%) compared with two out of 334 participants in the basal-bolus group (0.6%) died (low-certainty evidence). Severe hypoglycaemic episodes, defined as blood glucose levels below 40 mg/dL (2.2 mmol/L), showed a risk ratio (RR) of 0.22, 95% confidence interval (CI) 0.05 to 1.00; P = 0.05; 5 trials; 667 participants; very low-certainty evidence. The 95% prediction interval ranged between 0.02 and 2.57. All nine severe hypoglycaemic episodes were observed among the 369 participants on basal-bolus insulin (2.4%). The mean length of hospital stay was 0.5 days longer for the SSI group, 95% CI -0.5 to 1.4; P = 0.32; 6 trials; 717 participants; very low-certainty evidence. The 95% prediction interval ranged between -1.7 days and 2.7 days. Adverse events other than hypoglycaemic episodes, such as postoperative infections, showed a RR of 1.16, 95% CI 0.25 to 5.37; P = 0.85; 3 trials; 481 participants; very low-certainty evidence. The mean blood glucose levels ranged across basal-bolus groups from 156 mg/dL (8.7 mmol/L) to 221 mg/dL (12.3 mmol/L). The mean blood glucose level in the SSI groups was 14.8 mg/dL (0.8 mmol/L) higher (95% CI 7.8 (0.4) to 21.8 (1.2); P < 0.001; 6 trials; 717 participants; low-certainty evidence). The 95% prediction interval ranged between -3.6 mg/dL (-0.2 mmol/L) and 33.2 mg/dL (1.8 mmol/L). No trial reported on diabetes-related mortality or socioeconomic effects.

AUTHORS' CONCLUSIONS

We are uncertain which insulin strategy (SSI or basal-bolus insulin) is best for non-critically hospitalised adults with diabetes mellitus. A basal-bolus insulin strategy in these patients might result in better short-term glycaemic control but could increase the risk for severe hypoglycaemic episodes. The certainty of the body of evidence comparing SSI with basal-bolus insulin was low to very low and needs to be improved by adequately performed, well-powered RCTs in different hospital environments with well-educated medical staff using identical short-acting insulins in both intervention and comparator arms to compare the rigid SSI approach with flexible insulin application strategies.

Safety of the batteries and power units used in insulin pumps: A pilot cross-sectional study by the Association for the Study of Innovative Diabetes Treatment in Japan

AIMS/INTRODUCTION

We investigated the safety of the batteries and power units used in insulin pumps in Japan.

MATERIALS AND METHODS

A self-administered questionnaire was sent to the 201 members of the Association for Innovative Diabetes Treatment in Japan.

RESULTS

A total of 56 members responded, and among the 1,499 active devices, 66 had episodes of trouble related to the batteries and power units. The ratio of reported troubles to the number of insulin pumps was significantly higher in insulin pumps with a continuous glucose monitoring sensor compared with insulin pumps without a continuous glucose monitoring sensor (odds ratio 2.82, P < 0.05). The cause and the consequences varied. The brands of the batteries varied; alkaline batteries purchased at drug stores and other shops accounted for 19.7%. Termination of battery life within 72 h of use was reported most frequently (50.0%), suspension of the insulin pump (21.2%) and leakage of the battery fluid (4.5%) followed. A total of 53.2% of the reported insulin pumps needed to be replaced, and 37.1% of them recovered after replacement of the battery.

CONCLUSIONS

As trouble related to the batteries and power units of insulin pumps was frequent, practical guidance should be provided to respective patients regarding the use of reliable batteries, and to be well prepared for unexpected insulin pump failure.

Occlusion Detection Time in Insulin Pumps at Two Different Basal Rates

BACKGROUND

The detection of insulin infusion set (IIS) occlusions is an important feature of insulin pumps with regard to patient safety. However, there are no requirements for a time limit until an alarm has to be triggered after an occlusion occurred. The standard IEC 60601-2-24 is applicable for insulin pumps and describes test settings and procedures to determine occlusion detection time (ODT).

METHODS

In this study, ODT of six different insulin pump models with different IIS (in total 10 different insulin pump systems) was tested for two basal rates (1.0 U/h and 0.1 U/h).

RESULTS

Differences were seen between the tested pump systems. At a basal rate of 1.0 U/h all insulin pump systems showed an acceptable ODT of less than 5 hours. However, at a basal rate of 0.1 U/h, as often used in children, the median ODT ranged from approximately 4 hours to more than 40 hours. With the lower basal rate, median ODT was longer than 6-8 hours for 9 of the 10 systems.

CONCLUSIONS

Insulin pump users should not blindly rely on occlusion alarms but perform regular glucose monitoring and manufacturers should develop mechanisms that allow an earlier detection at low basal rates.

Comparison of Efficacy and Safety of Lispro and Aspart Evaluated by Continuous Glucose Monitoring System in Patients with Newly Diagnosed Type 2 Diabetes

OBJECTIVE

To compare the effect of the rapid-acting insulin analogues (RAIAs) aspart (NovoRapid) and lispro (Prandilin) on glycemic variations by continuous glucose monitoring system (CGMS) in patients within newly diagnosed type 2 diabetes mellitus (T2DM) receiving continuous subcutaneous insulin infusion (CSII) and metformin intensive therapy.

METHODS

This is a single-blind randomized controlled trial. A total of 110 patients with newly diagnosed T2DM and with hemoglobin A1c (HbA1c%) above 9% was hospitalized and randomly divided into two groups: group Asp (NovoRapid group) and group Lis (Prandilin group). They all received CSII and metformin therapy. Treatments were maintained for 2-3 weeks after the glycaemic target was reached. C-peptide and insulin and fructosamine were determined. CGMS was continuously applied for 4 days after reaching the glycemic target.

RESULTS

There were no significant differences in daily dosages of insulin, fasting plasma C-P and 2 h postprandial C-P and insulin, and fructosamine at the baseline and endpoint between the groups Asp and Lis. No significant differences were seen in the 24 h mean amplitude of glycemic excursions (MAGE), 24 h mean blood glucose (MBG), the standard deviation of the MBG (SDBG), fasting blood glucose, number of glycemic excursion (NGE), and the incidence of hypoglycemia between the two groups. Similarly, no significant differences were found in areas under the curve (AUC) of glucose above 10.0 mmol/L or the decremental area over the curve (AOC) of glucose below 3.9 mmol/L between the two groups.

CONCLUSIONS

Lispro and aspart had the similar ability to control the glycemic variations in patients with newly diagnosed T2DM. This study was registered with ClinicalTrials.gov, number ChiCTR-IPR-17010338.

Altered Patterns of Early Metabolic Decompensation in Type 1 Diabetes During Treatment with a SGLT2 Inhibitor: An Insulin Pump Suspension Study

BACKGROUND

Enthusiasm for the benefits of sodium-glucose cotransporter 2 inhibitors (SGLT2i) as an adjunctive treatment in type 1 diabetes (T1D) has been offset by the possible increased risk of diabetic ketoacidosis (DKA). Since pump-treated T1D patients are susceptible to DKA due to infusion site problems, this study was undertaken to assess how treatment with SGLT2i affects patterns of early metabolic decompensation following suspension of basal insulin.

METHODS

Ten T1D participants (age 19-35 years, duration 10 ± 8 years, A1c 7.4% ± 0.8%) underwent overnight pump suspension studies before and after treatment with canagliflozin (CANA). On both nights, basal insulin was suspended at 3 AM and plasma glucose (PG), β-hydroxybutyrate (BHB), free fatty acids (FFA), plasma insulin (PI), and glucagon were measured. Studies were terminated 6 h after suspension or if PG rose to >350 mg/dL or BHB >2.5 mmol/L.

RESULTS

PI levels at the start of suspension were reduced by 30% after CANA treatment (44 ± 11 uU/mL vs. 31 ± 10 uU/mL, P < 0.01), but baseline PG, BHB, FFA, and glucagon levels were not significantly different. During the suspension, PG rose from 104 ± 10 to 301 ± 21 mg/dL before treatment, but only from 109 ± 8 to 195 ± 14 mg/dL after treatment (P = 0.002 vs. pretreatment values). On the other hand, CANA treatment did not significantly affect the magnitude of increases in FFA, BHB, and glucagon levels during the suspension study.

CONCLUSION

These data indicate that SGLT2i do not accelerate the rate of ketogenesis following the interruption of basal insulin infusion in T1D. Rather, the failure of patients to promptly recognize early metabolic decompensation relates to the much more gradual rise in PG levels.

Ketone production in children with type 1 diabetes, ages 4-14 years, with and without nocturnal insulin pump suspension

OBJECTIVE

To compare the frequency of elevated morning blood ketone levels according to age in 4-14 year olds with type 1 diabetes following overnight use of an automated low glucose insulin suspension system, or following control nights when the system was not used.

RESEARCH DESIGN AND METHODS

For 28 children ages 4-9 years and 54 youth ages 10-14 years, elevation of morning blood ketone levels was assessed using the Precision Xtra Ketone meter following 1155 and 2345 nights, respectively. Repeated measures logistic regression models were used to compare age groups for blood ketone level elevation following control nights (system not activated) and following intervention nights with and without insulin suspension.

RESULTS

Elevated morning blood ketones (≥0.6 mmol/L) were present following 10% of 580 control nights in the 4-9 year olds compared with 2% of 1162 control nights in 10-14 year olds (P < 0.001). Likewise, the frequency was greater following intervention nights in the younger age group (13% of 575 nights vs 2% of 1183 nights, P < 0.001). A longer duration of pump suspension resulted in a higher percentage of mornings with elevated blood ketones in the younger age group (P = 0.002), but not in the older age group (P = 0.63). The presence of elevated morning ketone levels did not progress to ketoacidosis in any subject.

CONCLUSIONS

Elevated morning blood ketones are more common in younger children with type 1 diabetes with or without nocturnal insulin suspension. Care providers need to be aware of the differences in ketogenesis in younger age children relative to various clinical situations.

Asymmetric changes in circulating insulin levels after an increase compared with a reduction in insulin pump basal rate in people with Type 1 diabetes

AIMS

To investigate circulating insulin profiles after a clinically relevant insulin pump basal rate increase vs a reduction, and the associated glucose responses.

METHODS

A cohort of 12 adults with Type 1 diabetes undertook this two-stage university hospital study using Accu-Chek pumps (Roche Diagnostics, Mannheim, Germany) and insulin aspart. An insulin basal rate change of 0.2 unit/h (increase in first stage, reduction in second stage) was implemented at ~09:30 h, after a single overnight basal rate (without bolus insulin), while fasting participants rested. Frequent venous samples for the assessment of plasma free insulin, glucose and cortisol were collected from 60 min before until 300 min after rate change. The primary outcome was time to steady-state insulin.

RESULTS

The 0.2-unit/h rate change represented a mean ± sd alteration of 23 ± 6%. After the rate increase, the median (interquartile range) times to 80% and 90% steady-state insulin were 170 (45) min and 197 (87) min, respectively. By contrast, after rate reduction, 80% steady-state insulin was not achieved. After the rate increase, mean ± se insulin levels increased by 4.3 ± 3.1%, 12.0 ± 2.9% and 25.6 ± 2.6% at 60, 120 and 300 min, respectively (with no significant difference until 180 min). After the rate reduction, insulin decreased by 8.3 ± 3.0% at 300 min (with no significant difference until 300 min). After rate reduction, glucose levels paradoxically declined by 17.4 ± 3.7% after 300 min; cortisol levels also fell during observation (P = 0.0003).

CONCLUSIONS

The time to circulating insulin change after a 0.2-unit/h basal rate change was substantial, and was greater after a reduction than after an increase. Counter-regulatory hormone circadian variation may affect glycaemia when implementing minor changes at low basal rates. Both direction of basal rate change, and time of day, warrant consideration when anticipating the clinical effects of basal rate changes.

Insulin pump basal adjustment for exercise in type 1 diabetes: a randomised crossover study

AIMS/HYPOTHESIS

The aim of this study was to investigate the effects of exercise, vs rest, on circulating insulin and glucose, following pre-exercise insulin pump basal rate reduction.

METHODS

This was an open-label, two-stage randomised crossover study of 14 adults (seven women, seven men) with type 1 diabetes established on insulin pump therapy. In each stage, participants fasted and insulin delivery was halved following a single insulin basal rate overnight. Exercise (30 min moderate-intensity stationary bicycle exercise, starting 60 min post-basal reduction) and rest stages were undertaken in random order at a university hospital. Randomisation was computer-generated, and allocation concealed via sequentially numbered sealed opaque envelopes. Venous blood was collected at 15 min intervals from 60 min pre- until 210 min post-basal rate reduction. Changes in plasma free insulin (the primary outcome), and changes in plasma glucose, with exercise were compared with changes when resting. Outcomes were assessed blinded to group assignment.

RESULTS

Following basal rate reduction when rested, mean (± SE) free insulin decreased by 4.9 ± 2.9%, 16.2 ± 2.6% and 18.6 ± 3.2% at 1, 2 and 3 h, respectively (p < 0.05 after 75 min). With exercise, relative to rest, mean free insulin increased by 6 ± 2 pmol/l after 15 min and 5 ± 2 pmol/l after 30 min (p < 0.001), then declined post-exercise (p < 0.001). Three participants (mean baseline glucose 5.0 ± 0.1 mmol/l) required glucose supplementation to prevent or treat exercise-related hypoglycaemia. In the other 11 participants (mean baseline glucose 8.4 ± 0.5 mmol/l), glucose increased by 0.8 ± 0.3 mmol/l with exercise (p = 0.028).

CONCLUSIONS/INTERPRETATION

Halving the basal insulin rate 1 h prior to exercise did not significantly reduce circulating free insulin by exercise commencement. Exercise itself transiently increased insulin levels. In participants with low-normal glucose pre-exercise, hypoglycaemia was not prevented by insulin basal rate reduction alone. Greater insulin basal rate reduction and supplemental carbohydrate may be required to prevent exercise-induced hypoglycaemia.

TRIAL REGISTRATION

ANZCTR.org.au ACTRN12613000581763 FUNDING: Australian Diabetes Society, Hugh DT Williamson Foundation, Lynne Quayle Charitable Trust Fund.

Combined Insulin Deficiency and Endotoxin Exposure Stimulate Lipid Mobilization and Alter Adipose Tissue Signaling in an Experimental Model of Ketoacidosis in Subjects With Type 1 Diabetes: A Randomized Controlled Crossover Trial

Most often, diabetic ketoacidosis (DKA) in adults results from insufficient insulin administration and acute infection. DKA is assumed to release proinflammatory cytokines and stress hormones that stimulate lipolysis and ketogenesis. We tested whether this perception of DKA can be reproduced in an experimental human model by using combined insulin deficiency and acute inflammation and tested which intracellular mediators of lipolysis are affected in adipose tissue. Nine subjects with type 1 diabetes were studied twice: 1) insulin-controlled euglycemia and 2) insulin deprivation and endotoxin administration (KET). During KET, serum tumor necrosis factor-α, cortisol, glucagon, and growth hormone levels increased, and free fatty acids and 3-hydroxybutyrate concentrations and the rate of lipolysis rose markedly. Serum bicarbonate and pH decreased. Adipose tissue mRNA contents of comparative gene identification-58 (CGI-58) increased and G0/G1 switch 2 gene (G0S2) mRNA decreased robustly. Neither protein levels of adipose triglyceride lipase (ATGL) nor phosphorylations of hormone-sensitive lipase were altered. The clinical picture of incipient DKA in adults can be reproduced by combined insulin deficiency and endotoxin-induced acute inflammation. The precipitating steps involve the release of proinflammatory cytokines and stress hormones, increased lipolysis, and decreased G0S2 and increased CGI-58 mRNA contents in adipose tissue, compatible with latent ATGL stimulation.

[Insulin pump therapy in children, adolescents and adults]

This position statement is based on the current evidence available on the safety and benefits of continuous subcutaneous insulin pump therapy (CSII) in diabetes with an emphasis on the effects of CSII on glycemic control, hypoglycaemia rates, occurrence of ketoacidosis, quality of life and the use of insulin pump therapy in pregnancy. The current article represents the recommendations of the Austrian Diabetes Association for the clinical praxis of insulin pump treatment in children, adolescents and adults.

Subcutaneous rapid-acting insulin analogues for diabetic ketoacidosis

BACKGROUND

Diabetic ketoacidosis (DKA) is an acute, life-threatening complication of uncontrolled diabetes that mainly occurs in individuals with autoimmune type 1 diabetes, but it is not uncommon in some people with type 2 diabetes. The treatment of DKA is traditionally accomplished by the administration of intravenous infusion of regular insulin that is initiated in the emergency department and continued in an intensive care unit or a high-dependency unit environment. It is unclear whether people with DKA should be treated with other treatment modalities such as subcutaneous rapid-acting insulin analogues.

OBJECTIVES

To assess the effects of subcutaneous rapid-acting insulin analogues for the treatment of diabetic ketoacidosis.

SEARCH METHODS

We identified eligible trials by searching MEDLINE, PubMed, EMBASE, LILACS, CINAHL, and the Cochrane Library. We searched the trials registers WHO ICTRP Search Portal and ClinicalTrials.gov. The date of last search for all databases was 27 October 2015. We also examined reference lists of included randomised controlled trials (RCTs) and systematic reviews, and contacted trial authors.

SELECTION CRITERIA

We included trials if they were RCTs comparing subcutaneous rapid-acting insulin analogues versus standard intravenous infusion in participants with DKA of any age or sex with type 1 or type 2 diabetes, and in pregnant women.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data, assessed studies for risk of bias, and evaluated overall study quality utilising the GRADE instrument. We assessed the statistical heterogeneity of included studies by visually inspecting forest plots and quantifying the diversity using the I² statistic. We synthesised data using random-effects model meta-analysis or descriptive analysis, as appropriate.

MAIN RESULTS

Five trials randomised 201 participants (110 participants to subcutaneous rapid-acting insulin analogues and 91 to intravenous regular insulin). The criteria for DKA were consistent with the American Diabetes Association criteria for mild or moderate DKA. The underlying cause of DKA was mostly poor compliance with diabetes therapy. Most trials did not report on type of diabetes. Younger diabetic participants and children were underrepresented in our included trials (one trial only). Four trials evaluated the effects of the rapid-acting insulin analogue lispro, and one the effects of the rapid-acting insulin analogue aspart. The mean follow-up period as measured by mean hospital stay ranged between two and seven days. Overall, risk of bias of the evaluated trials was unclear in many domains and high for performance bias for the outcome measure time to resolution of DKA.No deaths were reported in the included trials (186 participants; 3 trials; moderate- (insulin lispro) to low-quality evidence (insulin aspart)). There was very low-quality evidence to evaluate the effects of subcutaneous insulin lispro versus intravenous regular insulin on the time to resolution of DKA: mean difference (MD) 0.2 h (95% CI -1.7 to 2.1); P = 0.81; 90 participants; 2 trials. In one trial involving children with DKA, the time to reach a glucose level of 250 mg/dL was similar between insulin lispro and intravenous regular insulin. There was very low-quality evidence to evaluate the effects of subcutaneous insulin aspart versus intravenous regular insulin on the time to resolution of DKA: MD -1 h (95% CI -3.2 to 1.2); P = 0.36; 30 participants; 1 trial. There was low-quality evidence to evaluate the effects of subcutaneous rapid-acting insulin analogues versus intravenous regular insulin on hypoglycaemic episodes: 6 of 80 insulin lispro-treated participants compared with 9 of 76 regular insulin-treated participants reported hypoglycaemic events; risk ratio (RR) 0.59 (95% CI 0.23 to 1.52); P = 0.28; 156 participants; 4 trials. For insulin aspart compared with regular insulin, RR for hypoglycaemic episodes was 1.00 (95% CI 0.07 to 14.55); P = 1.0; 30 participants; 1 trial; low-quality evidence. Socioeconomic effects as measured by length of mean hospital stay for insulin lispro compared with regular insulin showed a MD of -0.4 days (95% CI -1 to 0.2); P = 0.22; 90 participants; 2 trials; low-quality evidence and for insulin aspart compared with regular insulin 1.1 days (95% CI -3.3 to 1.1); P = 0.32; low-quality evidence. Data on morbidity were limited, but no specific events were reported for the comparison of insulin lispro with regular insulin. No trial reported on adverse events other than hypoglycaemic episodes, and no trial investigated patient satisfaction.

AUTHORS' CONCLUSIONS

Our review, which provided mainly data on adults, suggests on the basis of mostly low- to very low-quality evidence that there are neither advantages nor disadvantages when comparing the effects of subcutaneous rapid-acting insulin analogues versus intravenous regular insulin for treating mild or moderate DKA.

Automated insulin pump suspension for hypoglycaemia mitigation: development, implementation and implications

In type 1 diabetes (T1D), insulin replacement therapy should ideally replicate endogenous insulin secretion, but achieving this goal requires frequent adjustments to insulin delivery based on glucose levels and trends, carbohydrate intake and physical activity. An overriding concern for people taking insulin is hypoglycaemia, which remains the most feared consequence of insulin therapy and limits therapy intensification options. Although fully automated systems that achieve consistent euglycaemia in T1D remain an elusive goal, improvements in continuous glucose monitoring (CGM) sensors and control algorithms have enabled semi-automated systems that lower the risk of hypoglycaemia, especially nocturnal hypoglycaemia. The present review focuses on an important advance in insulin delivery systems: the use of CGM data to stop insulin delivery in the presence of hypoglycaemia. Although conceptually simple, this strategy represents a critical step in the journey toward a fully closed-loop artificial pancreas; the next steps in this journey are also discussed.

Accuracy of a new patch pump based on a microelectromechanical system (MEMS) compared to other commercially available insulin pumps: results of the first in vitro and in vivo studies

The JewelPUMP™ (JP) is a new patch pump based on a microelectromechanical system that operates without any plunger. The study aimed to evaluate the infusion accuracy of the JP in vitro and in vivo. For the in vitro studies, commercially available pumps meeting the ISO standard were compared to the JP: the MiniMed® Paradigm® 712 (MP), Accu-Chek® Combo (AC), OmniPod® (OP), Animas® Vibe™ (AN). Pump accuracy was measured over 24 hours using a continuous microweighing method, at 0.1 and 1 IU/h basal rates. The occlusion alarm threshold was measured after a catheter occlusion. The JP, filled with physiological serum, was then tested in 13 patients with type 1 diabetes simultaneously with their own pump for 2 days. The weight difference was used to calculate the infused insulin volume. The JP showed reduced absolute median error rate in vitro over a 15-minute observation window compared to other pumps (1 IU/h): ±1.02% (JP) vs ±1.60% (AN), ±1.66% (AC), ±2.22% (MP), and ±4.63% (OP), P < .0001. But there was no difference over 24 hours. At 0.5 IU/h, the JP was able to detect an occlusion earlier than other pumps: 21 (19; 25) minutes vs 90 (85; 95), 58 (42; 74), and 143 (132; 218) minutes (AN, AC, MP), P < .05 vs AN and MP. In patients, the 24-hour flow error was not significantly different between the JP and usual pumps (-2.2 ± 5.6% vs -0.37 ± 4.0%, P = .25). The JP was found to be easier to wear than conventional pumps. The JP is more precise over a short time period, more sensitive to catheter occlusion, well accepted by patients, and consequently, of potential interest for a closed-loop insulin delivery system.

Closed-loop system in the management of diabetes: past, present, and future

Intensive insulin therapy (IIT) has been shown to reduce micro- and macrovascular complications in patients with type 1 diabetes mellitus (T1DM). However, IIT is associated with a significant increase in severe hypoglycemic events, resulting in increased morbidity and mortality. Optimization of glycemic control without hypoglycemia (especially nocturnal) should be the next major goal for subjects on insulin treatment. The use of insulin pumps along with continuous glucose monitors (CGMs) has made it easier but requires significant resources and patient education. Research is ongoing to close the loop by integrating the pump and the CGM using different algorithms. The currently available closed-loop system is the threshold suspend. Steps needed to achieve a near-perfect closed-loop are (1) a control-to-range system that will reduce the incidence and/or severity of hyper- and/or hypoglycemia by adjusting the insulin dose and (2) a control-to-target system, a fully automated or hybrid system that sets target glucose levels to individual needs and maintains glucose levels throughout the day using insulin (unihormonal) alone or with other hormones such as glucagon or possibly pramlintide (bihormonal). Future research is also focusing on better insulin delivery devices (pumps), more accurate CGMs, better predictive algorithms, and ultra-rapid-acting insulin analogs to make the closed-loop system as physiological as possible.

A randomized trial of a home system to reduce nocturnal hypoglycemia in type 1 diabetes

OBJECTIVE

Overnight hypoglycemia occurs frequently in individuals with type 1 diabetes and can result in loss of consciousness, seizure, or even death. We conducted an in-home randomized trial to determine whether nocturnal hypoglycemia could be safely reduced by temporarily suspending pump insulin delivery when hypoglycemia was predicted by an algorithm based on continuous glucose monitoring (CGM) glucose levels.

RESEARCH DESIGN AND METHODS

Following an initial run-in phase, a 42-night trial was conducted in 45 individuals aged 15-45 years with type 1 diabetes in which each night was assigned randomly to either having the predictive low-glucose suspend system active (intervention night) or inactive (control night). The primary outcome was the proportion of nights in which ≥1 CGM glucose values ≤60 mg/dL occurred.

RESULTS

Overnight hypoglycemia with at least one CGM value ≤60 mg/dL occurred on 196 of 942 (21%) intervention nights versus 322 of 970 (33%) control nights (odds ratio 0.52 [95% CI 0.43-0.64]; P < 0.001). Median hypoglycemia area under the curve was reduced by 81%, and hypoglycemia lasting >2 h was reduced by 74%. Overnight sensor glucose was >180 mg/dL during 57% of control nights and 59% of intervention nights (P = 0.17), while morning blood glucose was >180 mg/dL following 21% and 27% of nights, respectively (P < 0.001), and >250 mg/dL following 6% and 6%, respectively. Morning ketosis was present <1% of the time in each arm.

CONCLUSIONS

Use of a nocturnal low-glucose suspend system can substantially reduce overnight hypoglycemia without an increase in morning ketosis.

Frequency of morning ketosis after overnight insulin suspension using an automated nocturnal predictive low glucose suspend system

OBJECTIVE

To assess the effect of overnight insulin pump suspension in an automated predictive low glucose suspend system on morning blood glucose and ketone levels in an attempt to determine whether routine measurement of ketone levels is useful when a closed-loop system that suspends insulin delivery overnight is being used.

RESEARCH DESIGN AND METHODS

Data from an in-home randomized trial of 45 individuals with type 1 diabetes (age range 15-45 years) were analyzed, evaluating an automated predictive low glucose pump suspension system in which blood glucose, blood ketone, and urine ketone levels were measured on 1,954 mornings.

RESULTS

One or more pump suspensions occurred during 744 of the 977 intervention nights (76%). The morning blood ketone level was ≥0.6 mmol/L after 11 of the 744 nights (1.5%) during which a pump suspension occurred and 2 of the 233 nights (0.9%) during which there was no suspension compared with 11 of 977 control nights (1.1%). The morning blood ketone level was ≥0.6 mmol/L after only 2 of 159 nights (1.3%) with a pump suspension exceeding 2 h. Morning fasting blood glucose level was not a good predictor of the presence of blood ketones.

CONCLUSIONS

Routine measurement of blood or urine ketones during use of an automated pump suspension system using continuous glucose monitoring, whether threshold based or predictive, is not necessary. Recommendations for checking ketone levels should be no different when a patient is using a system with automated insulin suspension than it is for conventional diabetes self-management.

Safety of nighttime 2-hour suspension of Basal insulin in pump-treated type 1 diabetes even in the absence of low glucose

OBJECTIVE

An integrated sensor-augmented pump system has been introduced that interrupts basal insulin infusion for 2 h if patients fail to respond to low-glucose alarms. It has been suggested that such interruptions of basal insulin due to falsely low glucose levels detected by sensor could lead to diabetic ketoacidosis. We hypothesized that random suspension of basal insulin for 2 h in the overnight period would not lead to clinically important increases in blood β-hydroxybutyrate levels despite widely varying glucose values prior to the suspension.

RESEARCH DESIGN AND METHODS

Subjects measured blood glucose and blood β-hydroxybutyrate levels using a meter each night at 9:00 p.m., then fasted until the next morning. On control nights, the usual basal rates were continued; on experimental nights, the basal insulin infusion was reprogrammed for a 2-h zero basal rate at random times after 11:30 p.m.

RESULTS

In 17 type 1 diabetic subjects (mean age 24 ± 9 years, diabetes duration 14 ± 11 years, A1C level 7.3 ± 0.5% [56 mmol/mol]), blood glucose and blood β-hydroxybutyrate levels were similar at 9:00 p.m. on suspend nights (144 ± 63 mg/dL and 0.09 ± 0.07 mmol/L) and nonsuspend nights (151 ± 65 mg/dL and 0.08 ± 0.06 mmol/L) (P = 0.39 and P = 0.47, respectively). Fasting morning blood glucose levels increased after suspend nights compared with nonsuspend nights (191 ± 68 vs. 141 ± 75 mg/dL, P < 0.0001), and the frequency of fasting hypoglycemia decreased the morning following suspend nights (P < 0.0001). Morning blood β-hydroxybutyrate levels were slightly higher after suspension (0.13 ± 0.14 vs. 0.09 ± 0.11 mmol/L, P = 0.053), but the difference was not clinically important.

CONCLUSIONS

Systems that suspend basal insulin for 2 h are safe and do not lead to clinically significant ketonemia even if the blood glucose level is elevated at the time of the suspension.

Artificial pancreas: model predictive control design from clinical experience

BACKGROUND

The objective of this research is to develop a new artificial pancreas that takes into account the experience accumulated during more than 5000 h of closed-loop control in several clinical research centers. The main objective is to reduce the mean glucose value without exacerbating hypo phenomena. Controller design and in silico testing were performed on a new virtual population of the University of Virginia/Padova simulator.

METHODS

A new sensor model was developed based on the Comparison of Two Artificial Pancreas Systems for Closed-Loop Blood Glucose Control versus Open-Loop Control in Patients with Type 1 Diabetes trial AP@home data. The Kalman filter incorporated in the controller has been tuned using plasma and pump insulin as well as plasma and continuous glucose monitoring measures collected in clinical research centers. New constraints describing clinical knowledge not incorporated in the simulator but very critical in real patients (e.g., pump shutoff) have been introduced. The proposed model predictive control (MPC) is characterized by a low computational burden and memory requirements, and it is ready for an embedded implementation.

RESULTS

The new MPC was tested with an intensive simulation study on the University of Virginia/Padova simulator equipped with a new virtual population. It was also used in some preliminary outpatient pilot trials. The obtained results are very promising in terms of mean glucose and number of patients in the critical zone of the control variability grid analysis.

CONCLUSIONS

The proposed MPC improves on the performance of a previous controller already tested in several experiments in the AP@home and JDRF projects. This algorithm complemented with a safety supervision module is a significant step toward deploying artificial pancreases into outpatient environments for extended periods of time.

Morbidity and mortality of diabetic ketoacidosis with and without insulin pump care

Diabetic ketoacidosis (DKA) is one of the most common, costly, and dangerous acute complications in people with type 1 diabetes (T1D). Although DKA has been reported to occur with less frequency than severe hypoglycemia, it is associated with a higher mortality rate and is the leading cause of diabetes-related deaths in children and adolescents. The most common risk factor for DKA is lack of adherence to insulin treatment. Other factors include underinsurance, psychiatric disorders, occlusion of insulin pump infusion sets, and illness. It has been suggested that use of continuous subcutaneous insulin infusion therapy may increase the risk for DKA, although clinical trials have not supported this claim. Expert care within a T1D specialty clinic may help reduce the risk of DKA mortality. Further advances are needed in developing new technologies and methods to improve glycemic control in intensively treated patients without increasing the risk of acute complications. The purpose of this review is to discuss DKA morbidity and mortality in youth with T1D, particularly in relation to insulin pump use.

New technologies for diabetes: a review of the present and the future

This review summarizes the technologies in use and in the pipeline for the management of diabetes. The review focuses on glucose meters, continuous glucose monitoring devices, insulin pumps, and getting clinicians connected to technologies. All information presented can be found in the public domain, and was obtained from journal articles, websites, product review tables in patient publications, and professional conferences. The technology concerns, ongoing development and future trends in this area are also discussed.

Insulin therapy in children and adolescents

Insulin therapy is the mainstay of treatment in children and adolescents with type 1 diabetes (T1D) and is a key component in the treatment of type 2 diabetes (T2D) in this population as well. A major aim of current insulin replacement therapy is to simulate the normal pattern of insulin secretion as closely as possible. This aim can best be achieved with basal-bolus therapy using multiple daily injections (MDI) or continuous insulin infusion (CSII) pump therapy. Only a few years ago, options for insulin formulations were limited. There are now more than 10 varieties of biosynthetic human and analogue insulin.

Cumulative clinical experience with use of insulin lispro: critical appraisal, role in therapy, and patient considerations

We have now at our disposal the new rapid-acting insulin analogs, of which insulin lispro was the first to become commercially available. While the differences in pharmacokinetic and pharmacodynamic characteristics are indisputable, the clinical benefits attained by these changes have not been as clear. In the present review, we discuss the structure, pharmacology, and landmark studies related to insulin lispro. The clinical characteristics of insulin lispro are compared with those of insulin regular and other insulin analogs in different clinical situations. Also included are the aspects of quality of life and cost-effectiveness that may modify the modern practitioner's decision to adopt one type of insulin over another.

Influence of physical activity on metabolic state within a 3-h interruption of continuous subcutaneous insulin infusion in patients with type 1 diabetes

BACKGROUND

The aim of this study was to evaluate the influence of physical activity on blood glucose, insulinemia, and ketone bodies level during interruption of insulin delivery.

METHODS

We enrolled 12 patients with type 1 diabetes (men with an average age of 33.4±8.66 years, body mass index of 25.7±3.75 mg/m(2), and glycated hemoglobin of 8.4±0.95%). The test was performed after overnight fasting at the usual insulin dosage. The delivery of insulin by the pump was stopped for 3 h, and blood samples were obtained in 30-min intervals for determination of blood glucose, insulinemia, β-hydroxybutyrate, non-esterified fatty acids, and acid-base balance parameters. A test with (EXE) or without (CON) physical exercise (moderate aerobic exercise) was performed in each patient at random in the course of 2 weeks. Results are presented as median (first quartile; third quartile).

RESULTS

Groups CON and EXE did not differ in blood levels of insulin during the test. Regarding time course of glycemia, we found differences only in min 270 for CON versus EXE of 15.2 (13.6; 16.7) and 13.9 (9.1;16.5) mmol/L, respectively (P=0.038). Concerning blood levels of β-hydroxybutyrate, we found significant differences in min 180-300 of the test: CON of 419 (354; 541), 485 (344; 580), and 107 (63; 156) μmol/L versus EXE of 690 (631; 723), 703 (562; 871), and 241 (113; 507) μmol/L (P<0.01). Comparable results were found in values of total ketone bodies and free fatty acids.

CONCLUSIONS

The influence of physical activity during a 3-h interruption of insulin pump treatment is evident, especially in the increase in plasma levels of non-esterified fatty acids and ketone bodies. Correction bolus leads to a rapid increase in insulinemia; however, normalization of blood glucose and ketone bodies is achieved within another 90 min.

New-generation diabetes management: glucose sensor-augmented insulin pump therapy

Diabetes is one of the most common chronic disorders with an increasing incidence worldwide. Technologic advances in the field of diabetes have provided new tools for clinicians to manage this challenging disease. For example, the development of continuous subcutaneous insulin infusion systems have allowed for refinement in the delivery of insulin, while continuous glucose monitors provide patients and clinicians with a better understanding of the minute to minute glucose variability, leading to the titration of insulin delivery based on this variability when applicable. Merging of these devices has resulted in sensor-augmented insulin pump therapy, which became a major building block upon which the artificial pancreas (closed-loop systems) can be developed. This article summarizes the evolution of sensor-augmented insulin pump therapy until present day and its future applications in new-generation diabetes management.

Closed-loop insulin delivery for treatment of type 1 diabetes

Type 1 diabetes is one of the most common endocrine problems in childhood and adolescence, and remains a serious chronic disorder with increased morbidity and mortality, and reduced quality of life. Technological innovations positively affect the management of type 1 diabetes. Closed-loop insulin delivery (artificial pancreas) is a recent medical innovation, aiming to reduce the risk of hypoglycemia while achieving tight control of glucose. Characterized by real-time glucose-responsive insulin administration, closed-loop systems combine glucose-sensing and insulin-delivery components. In the most viable and researched configuration, a disposable sensor measures interstitial glucose levels, which are fed into a control algorithm controlling delivery of a rapid-acting insulin analog into the subcutaneous tissue by an insulin pump. Research progress builds on an increasing use of insulin pumps and availability of glucose monitors. We review the current status of insulin delivery, focusing on clinical evaluations of closed-loop systems. Future goals are outlined, and benefits and limitations of closed-loop therapy contrasted. The clinical utility of these systems is constrained by inaccuracies in glucose sensing, inter- and intra-patient variability, and delays due to absorption of insulin from the subcutaneous tissue, all of which are being gradually addressed.

Prevention of hypoglycemia by using low glucose suspend function in sensor-augmented pump therapy

BACKGROUND

Severe hypoglycemic episodes are a barrier for achieving optimal glycemic control. Sensor-augmented pump (SAP) therapy with insulin in combination with a novel mechanism of automatic insulin shutoff (low glucose suspend [LGS]) can be used to prevent and reduce hypoglycemia. In a prospective study, we investigated the effect of the LGS algorithm on the frequency of hypoglycemia in children and adolescents with type 1 diabetes under real-life conditions.

METHODS

Twenty-one patients with type 1 diabetes (10.8±3.8 years old, duration of diabetes 5.9±3.0 years, pump therapy for 3.7±1.7 years, glycated hemoglobin level 7.8±1.1%) from three pediatric centers used the Paradigm(®) Veo(™) system (Medtronic Minimed, Northridge, CA) during two subseqent time periods: SAP without LGS for 2 weeks and then SAP with LGS enabled for 6 weeks. The primary objective was to assess the frequency of hypoglycemic episodes when using the LGS feature with an insulin delivery shutoff of a maximum of 2 h at a sensor glucose level below 70 mg/dL (3.9 mmol/L).

RESULTS

In total, 1,298 LGS alerts occurred (853 shorter than 5 min). Forty-two percent of LGS activations (>5 min) lasted less than 30 min, whereas 24% had a duration of 2 h. The number of hypoglycemic excursions (average/day) was reduced during SAP+LGS (<70 mg/L, 1.27±0.75 vs. 0.95±0.49, P=0.010; ≤40 mg/dL, 0.28±0.18 vs. 0.13±0.14, P=0.005) as was the time spent in hypoglycemia (average minutes/day, 101±68 vs. 58±33, P=0.002) without significant difference in the mean glucose level (145±23 vs. 148±19 mg/dL). No episodes of severe hyperglycemia or diabetic ketoacidosis were observed following LGS activation.

CONCLUSIONS

The present investigation provides evidence that SAP with LGS reduces the frequency of hypoglycemia without compromising safety.

Innovations in technology for the treatment of diabetes: clinical development of the artificial pancreas (an autonomous system)

The Food and Drug Administration in collaboration with the National Institutes of Health presented a public workshop to facilitate medical device innovation in the development of the artificial pancreas (or autonomous system) for the treatment of diabetes mellitus on November 10, 2010 in Gaithersburg, Maryland. The purpose of the workshop was to discuss four aspects of artificial pancreas research and development, including: (1) the current state of device systems for autonomous systems for the treatment of diabetes mellitus; (2) challenges in developing this expert device system using existing technology; (3) clinical expectations for these systems; and (4) development plans for the transition of this device system toward an outpatient setting. The patients discussed how clinical science, system components, and regulatory policies will all need to harmonize in order to achieve the goal of seeing an AP product brought forward to the marketplace for patients to use.

Suspended insulin infusion during overnight closed-loop glucose control in children and adolescents with Type 1 diabetes

AIMS

We assessed an extended interruption of subcutaneous insulin delivery during overnight closed-loop glucose control in children and adolescents with Type 1 diabetes (T1D).

METHODS

In seven young subjects with T1D [age 14.2+/-2.1 years, diabetes duration 6.9+/-4.0 years, glycated haemoglobin (HbA1c) 8.0+/-1.5%, body mass index (BMI) 21.4+/-4.0 kg/m2, total daily insulin dose 0.9+/-0.2 units/kg/day; mean+/-sd) participating in overnight closed-loop glucose control studies, insulin delivery was interrupted for at least 90 min on the basis of predicted hypoglycaemia, low prevailing glucose levels or a too-steep decline in glucose levels.

RESULTS

Insulin delivery was interrupted for 165 (105, 210) min [median, interquartile range (IQR)]. Plasma glucose was 6.2+/-3.2 mmol/l at the time of interruption and 5.5+/-2.0 mmol/l 105 min later (P=0.15, paired t-test). Plasma glucose declined during the first hour of the interruption at a rate of 0.02+/-0.03 mmol/l per min and reached a nadir of 5.2+/-2.7 mmol/l; 105 min after the interruption, plasma glucose was increasing at a rate of 0.01+/-0.03 mmol/l per min. When insulin delivery restarted, plasma glucose was 6.4+/-2.2 mmol/l and peaked at 7.9+/-2.1 mmol/l in 60 min (P=0.01). Physiological levels of plasma insulin were measured throughout with a nadir of 119+/-78 pmol/l.

CONCLUSIONS

A prolonged interruption of insulin delivery during overnight closed-loop glucose control to prevent hypoglycaemia was not associated with an increased risk of hyperglycaemia in young people with T1D.

Is an automatic pump suspension feature safe for children with type 1 diabetes? An exploratory analysis with a closed-loop system

OBJECTIVES

It has been proposed that the first step towards a closed-loop artificial pancreas might be to use a continuous glucose sensor to automatically suspend the basal insulin delivery based on projected low sensor glucose values.

METHODS

We reviewed our recent experience with an artificial pancreas system, utilizing a proportional-integrative-derivative (PID) algorithm, in 17 adolescents with type 1 diabetes (T1D) to assess the safety and efficacy of this maneuver.

RESULTS

During 34 h of closed-loop automated insulin delivery, 18 pump suspensions > or =60 min (90 +/- 18 min) occurred in eight subjects. Sensor glucose levels fell from 159 +/- 42 mg/dL to a nadir of 72 +/- 13 mg/dL. Corresponding plasma glucose levels fell from 168 +/- 51 to 72 +/- 16 mg/dL, with values <60 mg/dL recorded in only four of the 18 events.

CONCLUSIONS

These data suggest that automatic pump suspension using the PID algorithm may be an effective means to prevent hypoglycemia in youth with T1D.

Treatment of diabetes mellitus using an external insulin pump: the state of the art

The aim of diabetes treatment is to achieve tight glucose control to avoid the development of chronic diabetic complications while reducing the frequency of hypoglycaemic episodes. Continuous subcutaneous insulin infusion (CSII) using an external pump is an intensive diabetes therapy recognized to improve metabolic control and glycaemic instability, and to reduce the frequency of severe hypoglycaemia. For years, the theoretical advantages of the insulin pump (constancy of basal delivery, adjustable basal rates, and low insulin depots allowing the reduction of glycaemic variability) have contributed to its reported superiority compared with multiple daily injections (MDI). However, insulin pump therapy is now challenged by new MDI regimens based on long-acting insulin analogues that could replace the use of CSII. As a consequence, health professionals now have to determine which patients are likely to benefit the most from CSII. Recently, several studies reported that children and adolescents, and patients whose blood glucose imbalance was initially the most pronounced with basal-bolus regimens, would particularly benefit from CSII. Other indications were also proposed in marginal clinical situations with highly selected patients in whom a significant improvement of blood glucose was demonstrated. Finally, the use of CSII in type 2 diabetic patients now appears to be a good alternative to the ineffective MDI regimens observed in some of these patients. However, past experience with CSII indicates that candidates for insulin pump therapy must be carefully selected and strongly motivated to improve their glucose control. Use of CSII also requires strict medical supervision by physicians and a regular programme of patient education by paramedical teams, to ensure optimal responsible use of this technique by healthcare professionals.

Unexplained hyperglycemia in continuous subcutaneous insulin infusion: evaluation and treatment

PURPOSE

The purpose of this review study was to determine and categorize common causes of intermittent hyperglycemia and suggest potential measures to prevent and treat the identified causes.

METHODS

A literature review was conducted to obtain relevant information on hyperglycemia and continuous subcutaneous insulin infusion (CSII). Medical departments from Novo/Nordisk, Eli Lilly and Company, and Sanofi/Aventis were contacted requesting information on their insulin temperature stability, the compatibility of insulin with insulin/pump reservoirs, and tubing sets/catheters. Endocrinologists, Certified Diabetes Educators, and pump manufacturing company trainers were interviewed for their clinical observations and to determine the incidence of reported hyperglycemia and relationships to pump failures.

RESULTS

Causes of intermittent hyperglycemia in CSII patients included problems with mechanical evaluation of the pump, basal/bolus review, reservoir/tubing, catheter site selection/placement, and insulin compatibility/stability.

CONCLUSIONS

As more patients and health care providers strive to improve control of diabetes, use of insulin pump therapy will continue to increase. Unexplained hyperglycemia will continue to occur, which can lead to increased health care costs due to complications such as diabetic ketoacidosis. Evaluation of patient techniques and pump programming can uncover many potential causes, and the health care provider can assist in patient education to prevent further episodes.

Quantifying the impact of a short-interval interruption of insulin-pump infusion sets on glycemic excursions

This prospective, open-label study was designed to measure the impact of short-term infusion-set disconnects on glucose levels. Continuous subcutaneous insulin infusion therapy allows for uninterrupted delivery of insulin. Patients disconnect their insulin pumps from their infusion sets when showering, swimming, exercising, or during intimate moments. Interrupting insulin infusion results in cessation of basal insulin delivery. Nineteen subjects with type 1 diabetes were studied on two separate in-clinic days. One hour after arriving at the clinic in a fasting state, subjects either temporarily disconnected their infusion sets from their pumps, interrupting basal insulin infusion for 30 min, or, on a separate day, changed their infusion sets. Glucose levels were monitored for an additional 4 h on both occasions. Changing infusion sets did not affect short-term glucose control. However, the 30-min interruption of basal insulin infusion resulted in significant glucose elevation; approximately 1 mg/dl for each minute basal insulin infusion was interrupted.

A morning dose of insulin glargine prevents nocturnal ketosis after postprandial interruption of continuous subcutaneous insulin infusion with insulin lispro

AIM

The aim of this crossover trial was to evaluate the potential of partial substitution of basal insulin with glargine, administered once daily in the morning, to protect against nocturnal ketosis after postprandial interruption of continuous subcutaneous insulin infusion (CSII).

METHODS

Seven patients with type 1 diabetes received 4 weeks of treatment with insulin lispro, administered by CSII, and 4 weeks of treatment with CSII and a partial basal replacement dose of insulin glargine administered in the morning. On day 28 of each treatment phase, patients were admitted to the research unit where dinner was served and their usual dinner insulin bolus dose given, after which CSII was discontinued at 7 pm. Plasma (p) beta-hydroxybutyrate and p glucose were measured every hour for 12 h thereafter.

RESULTS

Plasma beta-hydroxybutyrate at 7 pm was 0.16+/-0.05 and 0.13+/-0.07 mmol/l with and without glargine, respectively, and increased to 0.17+/-0.10 and 0.60+/-0.3 mmol/l within 6 h (P=0.02). Plasma glucose increased without glargine, from 8.6+/-2.9 to 21.1+/-3.0 mmol/l (P=0.003), but did not rise significantly following glargine (13.6+/-4.7 vs. 12.6+/-5.6 mmol/l; P=0.65).

CONCLUSIONS

Partial replacement with a morning dose of insulin glargine protects against the development of ketosis for as much as 12 h after postprandial interruption of CSII. This treatment strategy could, therefore, be useful for patients who are prone to ketosis but, for other reasons, are deemed suitable for CSII.

Continuous subcutaneous insulin infusion vs intensive conventional insulin therapy in pregnant diabetic women: a systematic review and metaanalysis of randomized, controlled trials

The objective of the study was to study the effects of continuous subcutaneous insulin infusion (CSII) vs multiple-dose insulin (MDI) therapy on glycemic control and pregnancy outcome in diabetic women. Randomized, controlled trials comparing CSII vs MDI in pregnant diabetic women were included after an electronic database search. Studies were rated for quality independently by 2 reviewers in accordance with the Quality of Reporting of Metaanalyses statement. Summary weighted mean difference and odds ratio were estimated for insulin dose, birthweight, gestational age, mode of delivery, hypoglycemic/ketotic episodes, worsening retinopathy, neonatal hypoglycemia, and rates of intrauterine fetal death. Six randomized clinical trials met the inclusion criteria. Pregnancy outcomes and glycemic control were not significantly different among treatment groups. Higher number of ketoacidotic episodes and diabetic retinopathy found in the CSII group did not reach statistical significance. This systematic review does not show any advantage or disadvantage of using CSII over MDI in pregnant diabetic women. Large multicenter, randomized, controlled trials addressing the quality of life/cost effectiveness are required.

Can we prevent diabetic ketoacidosis in children?

Diabetic ketoacidosis (DKA) is an acute potentially life-threatening complication of diabetes affecting more than 100,000 persons annually in the United States. Although major advances have improved diabetes care, DKA remains the leading cause of hospitalization, morbidity, and death in youth with type 1 diabetes (T1D). As the majority of patients presenting with DKA have established diabetes, it is important to address outpatient educational approaches directed at sick-day management and early identification and treatment of impending DKA. Teaching and reinforcement of sick-day rules involves improved self-care with consistent self-monitoring of blood glucose and ketones, and timely administration of supplemental insulin and fluids. DKA as an initial manifestation of T1D may be less amendable to prevention except with an increased awareness by the lay and medical communities of the symptoms of diabetes and surveillance in high-risk populations potentially identified by family history or genetic susceptibility. New technologies that can detect the blood ketone 3beta-hydroxybutyrate (3beta-OHB) instead of traditional urine ketones appears to provide opportunity for early identification and treatment of impending DKA leading to reduced need for hospitalization and potential cost-savings.

Performance of the continuous glucose monitoring system (CGMS) during development of ketosis in patients on insulin pump therapy

AIMS

Ketoacidosis is one of the most severe complications of Type 1 diabetes. Development of ketosis leads to substantial shifts in electrolyte and ion concentrations in the different fluid compartments of the body. This study was performed to investigate the performance of the continuous glucose monitoring device (CGMS) during ketoacidosis.

METHODS

Twelve patients with Type 1 diabetes using continuous subcutaneous insulin infusion (CSII) participated in this trial [10 women, two men; age (mean +/- sd) 34 +/- 9 years; disease duration 17 +/- 10 years; HbA(1c) 7.1 +/- 1.0%]. In the morning, patients ate breakfast and the insulin pump was stopped at 11.00 h and restarted after 8 h. Observation parameters during this experiment were: blood glucose (laboratory reference and CGMS), 3-hydroxy-butyrate (3-OHB), pH, Na, pCO(2), pO(2), free fatty acids, osmolarity, standard bicarbonate, and lactate.

RESULTS

Blood glucose increased and reached a plateau within 2 h after pump stop (from 6.2 +/- 2.56 to 16.7 +/- 4.44 mmol/l, P < 0.001). A constant increase in 3-OHB (from 0.0 to 0.8 +/- 0.5 mmol/l, P < 0.001) and decrease in pH (from 7.43 +/- 0.02 to 7.40 +/- 0.03, P < 0.05) indicated ketosis development. Na decreased from 141 +/- 1.4 to 138 +/- 2.8 mmol/l, P < 0.001). Free fatty acids increased from 0.577 +/- 0.330 to 1.330 +/- 0.462 mmol/l (P < 0.001). The CGMS values showed excellent agreement with the capillary blood laboratory method during the entire experiment, and a modified error grid analysis revealed that 99.5% of the values were in the clinically acceptable zones A and B.

CONCLUSION

The CGMS device was confirmed to be reliable and accurate during the development of hyperglycaemia and ketotic conditions.