Frequency of biochemical hypoglycaemia in adults with Type 1 diabetes with and without impaired awareness of hypoglycaemia: no identifiable differences using continuous glucose monitoring

A cross-sectional questionnaire study: Impaired awareness of hypoglycaemia remains prevalent in adults with type 1 diabetes and is associated with the risk of severe hypoglycaemia

OBJECTIVE

Impaired awareness of hypoglycaemia (IAH) is a risk factor for severe hypoglycaemia (SH) in type 1 diabetes (T1D). Much of the IAH prevalence data comes from older studies where participants did not have the benefit of the latest insulins and technologies. This study surveyed the prevalence of IAH and SH in a tertiary adult clinic population and investigated the associated factors.

METHODS

Adults (≥18 years) attending a tertiary T1D clinic completed a questionnaire, including a Gold and Clarke score. Background information was collected from health records.

RESULTS

189 people (56.1% female) with T1D (median [IQR] disease duration 19.3 [11.5, 29.1] years and age of 41.0 [29.0, 52.0] years) participated. 17.5% had IAH and 16.0% reported ≥1 episode of SH in the previous 12 months. Those with IAH were more likely to report SH (37.5% versus 11.7%, p = 0.001) a greater number of SH episodes per person (median [IQR] 0 [0,2] versus 0 [0,0] P<0.001) and be female (72.7% versus 52.6%, p = 0.036). Socio-economic deprivation was associated with IAH (p = 0.032) and SH (p = 0.005). Use of technology was the same between IAH vs aware groups, however, participants reporting SH were more likely to use multiple daily injections (p = 0.026). Higher detectable C-peptide concentrations were associated with a reduced risk of SH (p = 0.04).

CONCLUSION

Insulin pump and continuous glucose monitor use was comparable in IAH versus aware groups. Despite this, IAH remains a risk factor for SH and is prevalent in females and in older people. Socioeconomic deprivation was associated with IAH and SH, making this an important population to target for interventions.

Advanced decision support system for individuals with diabetes on multiple daily injections therapy using reinforcement learning and nearest-neighbors: In-silico and clinical results

Many individuals with diabetes on multiple daily insulin injections therapy use carbohydrate ratios (CRs) and correction factors (CFs) to determine mealtime and correction insulin boluses. The CRs and CFs vary over time due to physiological changes in individuals' response to insulin. Errors in insulin dosing can lead to life-threatening abnormal glucose levels, increasing the risk of retinopathy, neuropathy, and nephropathy. Here, we present a novel learning algorithm that uses Q-learning to track optimal CRs and uses nearest-neighbors based Q-learning to track optimal CFs. The learning algorithm was compared with the run-to-run algorithm A and the run-to-run algorithm B, both proposed in the literature, over an 8-week period using a validated simulator with a realistic scenario created with suboptimal CRs and CFs values, carbohydrate counting errors, and random meals sizes at random ingestion times. From Week 1 to Week 8, the learning algorithm increased the percentage of time spent in target glucose range (4.0 to 10.0 mmol/L) from 51 % to 64 % compared to 61 % and 58 % with the run-to-run algorithm A and the run-to-run algorithm B, respectively. The learning algorithm decreased the percentage of time spent below 4.0 mmol/L from 9 % to 1.9 % compared to 3.4 % and 2.3 % with the run-to-run algorithm A and the run-to-run algorithm B, respectively. The algorithm was also assessed by comparing its recommendations with (i) the endocrinologist's recommendations on two type 1 diabetes individuals over a 16-week period and (ii) real-world individuals' therapy settings changes of 23 individuals (19 type 2 and 4 type 1) over an 8-week period using the commercial Bigfoot Unity Diabetes Management System. The full agreements (i) were 89 % and 76 % for CRs and CFs for the type 1 diabetes individuals and (ii) was 62 % for mealtime doses for the individuals on the commercial Bigfoot system. Therefore, the proposed algorithm has the potential to improve glucose control in individuals with type 1 and type 2 diabetes.

Intermittently scanned continuous glucose monitoring and hypoglycaemia awareness in drivers with diabetes: Insights from the Association of British Clinical Diabetologists Nationwide audit

AIM

Frequent hypoglycaemia results in disruption to usual hypoglycaemic autonomic responses leading to impaired awareness of hypoglycaemia, which is associated with an increased risk of severe hypoglycaemia requiring third-party assistance (SH). The UK Driving and Vehicle Licensing Agency (DVLA) does not permit car driving if they have either a complete loss of hypoglycaemia awareness or more than one SH event a year.

METHODS

The FreeStyle Libre (FSL) Association of British Clinical Diabetologists (ABCD) Nationwide Audit consists of data collected by clinicians during routine clinical work, submitted into a secure web-based tool held within the National Health Service (NHS) N3 network. Analysis of paired baseline and follow-up data for people with type 1 diabetes who also held a driving licence was undertaken.

RESULTS

The study consisted of 6304 people who had data recorded about driving status from 102 UK specialist diabetes centres, of which 4218 held a driving licence: 4178 a group 1, standard licence, 33 a group 2, large lorries and buses, seven a taxi licence; 1819 did not drive. Paired baseline and follow-up data were available for a sub-cohort of 1606/4218. At a mean follow-up of 6.9 months [95% CI (6.8, 7.1)], the Gold score had improved (2.3 ± 1.5 vs. 2.0 ± 1.3 p < .001), and the number of people who experienced an SH episode was also significantly lower (12.1% vs. 2.7%, p < .001).

CONCLUSION

This study suggests that intermittently scanned continuous glucose monitoring may improve impaired awareness of hypoglycaemia and reduce the number of people with type 1 diabetes with a driving licence experiencing a severe hypoglycaemic episode.

Safety and Efficacy of Sustained Automated Insulin Delivery Compared With Sensor and Pump Therapy in Adults With Type 1 Diabetes at High Risk for Hypoglycemia: A Randomized Controlled Trial

OBJECTIVE

Assess the safety and efficacy of automated insulin delivery (AID) in adults with type 1 diabetes (T1D) at high risk for hypoglycemia.

RESEARCH DESIGN AND METHODS

Participants were 72 adults with T1D who used an insulin pump with Clarke Hypoglycemia Perception Awareness scale score >3 and/or had severe hypoglycemia during the previous 6 months confirmed by time below range (TBR; defined as sensor glucose [SG] reading <70 mg/dL) of at least 5% during 2 weeks of blinded continuous glucose monitoring (CGM). Parallel-arm, randomized trial (2:1) of AID (Tandem t:slim ×2 with Control-IQ technology) versus CGM and pump therapy for 12 weeks. The primary outcome was TBR change from baseline. Secondary outcomes included time in target range (TIR; 70-180 mg/dL), time above range (TAR), mean SG reading, and time with glucose level <54 mg/dL. An optional 12-week extension with AID was offered to all participants.

RESULTS

Compared with the sensor and pump (S&P), AID resulted in significant reduction of TBR by -3.7% (95% CI -4.8, -2.6), P < 0.001; an 8.6% increase in TIR (95% CI 5.2, 12.1), P < 0.001; and a -5.3% decrease in TAR (95% CI -87.7, -1.8), P = 0.004. Mean SG reading remained similar in the AID and S&P groups. During the 12-week extension, the effects of AID were sustained in the AID group and reproduced in the S&P group. Two severe hypoglycemic episodes occurred using AID.

CONCLUSIONS

In adults with T1D at high risk for hypoglycemia, AID reduced the risk for hypoglycemia more than twofold, as quantified by TBR, while improving TIR and reducing hyperglycemia. Hence, AID is strongly recommended for this specific population.

Commentary to accompany Flatt et al., Automated insulin delivery for hypoglycemia avoidance and glucose counterregulation in longstanding type 1 diabetes with hypoglycemia unawareness

N/A.

Altered functional connectivity during hypoglycaemia in type 1 diabetes

Behavioural responses to hypoglycaemia require coordinated recruitment of broadly distributed networks of interacting brain regions. We investigated hypoglycaemia-related changes in brain connectivity in people without diabetes (ND) and with type 1 diabetes with normal (NAH) or impaired (IAH) hypoglycaemia awareness. Two-step hyperinsulinaemic hypoglycaemic clamps were performed in 14 ND, 15 NAH and 22 IAH participants. BOLD timeseries were acquired at euglycaemia (5.0 mmol/L) and hypoglycaemia (2.6 mmol/L), with symptom and counter-regulatory hormone measurements. We investigated hypoglycaemia-related connectivity changes using established seed regions for the default mode (DMN), salience (SN) and central executive (CEN) networks and regions whose activity is modulated by hypoglycaemia: the thalamus and right inferior frontal gyrus (RIFG). Hypoglycaemia-induced changes in the DMN, SN and CEN were evident in NAH (all p < 0.05), with no changes in ND or IAH. However, in IAH there was a reduction in connectivity between regions within the RIFG (p = 0.001), not evident in the ND or NAH groups. We conclude that hypoglycaemia induces coordinated recruitment of the DMN and SN in diabetes with preserved hypoglycaemia awareness which is absent in IAH and ND. Changes in connectivity in the RIFG, a region associated with attentional modulation, may be key in impaired hypoglycaemia awareness.

Hybrid Closed-Loop Systems for the Treatment of Type 1 Diabetes: A Collaborative, Expert Group Position Statement for Clinical Use in Central and Eastern Europe

In both pediatric and adult populations with type 1 diabetes (T1D), technologies such as continuous subcutaneous insulin infusion (CSII), continuous glucose monitoring (CGM), or sensor-augmented pumps (SAP) can consistently improve glycemic control [measured as glycated hemoglobin (HbA1c) and time in range (TIR)] while reducing the risk of hypoglycemia. Use of technologies can thereby improve quality of life and reduce the burden of diabetes management compared with self-injection of multiple daily insulin doses (MDI). Novel hybrid closed-loop (HCL) systems represent the latest treatment modality for T1D, combining modern glucose sensors and insulin pumps with a linked control algorithm to offer automated insulin delivery in response to blood glucose levels and trends. HCL systems have been associated with increased TIR, improved HbA1c, and fewer hypoglycemic events compared with CSII, SAP, and MDI, thereby potentially improving quality of life for people with diabetes (PwD) while reducing the costs of treating short- and long-term diabetes-related complications. However, many barriers to their use and regional inequalities remain in Central and Eastern Europe (CEE). Published data suggest that access to diabetes technologies is hindered by lack of funding, underdeveloped health technology assessment (HTA) bodies and guidelines, unfamiliarity with novel therapies, and inadequacies in healthcare system capacities. To optimize the use of diabetes technologies in CEE, an international meeting comprising experts in the field of diabetes was held to map the current regional access, to present the current national reimbursement guidelines, and to recommend solutions to overcome uptake barriers. Recommendations included regional and national development of HTA bodies, efficient allocation of resources, and structured education programs for healthcare professionals and PwD. The responsibility of the healthcare community to ensure that all individuals with T1D gain access to modern technologies in a timely and economically responsible manner, thereby improving health outcomes, was emphasized, particularly for interventions that are cost-effective.

Analysis Estimating the Potential Cost Impact of Utilizing Flash Glucose Monitoring with Optional Alarms in Swedish Adults with Diabetes with Impaired Awareness of Hypoglycaemia, Using Intensive Insulin

INTRODUCTION

The objective of this analysis was to estimate the costs associated with using flash glucose monitoring with optional alarms as a replacement for either traditional continuous glucose monitoring (CGM) or routine self-monitoring of blood glucose (SMBG) in adults with diabetes and impaired awareness of hypoglycaemia (IAH) who use intensified insulin therapy, from a Swedish payer perspective, applying assumptions to simulate hypothetical scenarios.

METHODS

A simple two-state cohort Markov model was used to calculate the cost per patient treated over a 3-year period, capturing the risk of severe hypoglycaemic events requiring medical assistance and non-adherence using quarterly Markov cycles. The costs considered were those for glucose monitoring and resource use to treat severe hypoglycaemic events. Cost inputs were sourced from Swedish price lists, manufacturer data and resource use reported in the control arm of the HypoDE study. Targeted literature searches were run in PubMed to source the clinical inputs. Uncertainty in the model was considered through one-way sensitivity analysis and scenario analysis.

RESULTS

Over 3 years, flash monitoring with optional alarms resulted in potential cost-savings of Swedish krona (SEK) 7708 and SEK 69,908 per patient when compared to routine SMBG or CGM respectively. Sensitivity and scenario analyses were largely supportive of this conclusion with respect to SMBG, and large cost-savings were consistent across all sensitivity and scenario analyses with respect to CGM.

CONCLUSION

Utilizing flash monitoring with optional alarms is potentially a cost-saving treatment strategy compared to routine SMBG or traditional CGM in adults with diabetes using intensive insulin and IAH from a Swedish payer perspective. Future studies in the IAH population will help to assess more precisely the relative cost impact of flash glucose monitoring with optional alarms compared with SMBG and traditional CGM.

Long-term use of the hybrid artificial pancreas by adjusting carbohydrate ratios and programmed basal rate: A reinforcement learning approach

BACKGROUND AND OBJECTIVES

The hybrid artificial pancreas regulates glucose levels in people with type 1 diabetes. It delivers (i) insulin boluses at meal times based on the meals' carbohydrate content and the carbohydrate ratios (CRs) and (ii) insulin basal, between meals and at night, continuously modulated around individual-specific programmed basal rate. The CRs and programmed basal rate significantly vary between individuals and within the same individual with type 1 diabetes, and using suboptimal values in the hybrid artificial pancreas may degrade glucose control. We propose a reinforcement learning algorithm to adaptively optimize CRs and programmed basal rate to improve the performance of the hybrid artificial pancreas.

METHODS

The proposed reinforcement learning algorithm was designed using the Q-learning approach. The algorithm learns the optimal actions (CRs and programmed basal rate) by applying them to the individual's state (previous day's glucose levels and insulin delivery) based on an exploration and exploitation trade-off. First, outcomes from our simulator were compared to those of a clinical study in 23 individuals with type 1 diabetes and have yielded similar results. Second, the learning algorithm was tested using the simulator with two scenarios. Scenario 1 has fixed meal sizes and ingestion times and scenario 2 has a more realistic eating behavior with random meal sizes, ingestion times, and carbohydrate counting errors.

RESULTS

After about five weeks, the reinforcement learning algorithm improved the percentage of time spent in target range from 67% to 86.7% in scenario 1 and 65.5% to 86% in scenario 2. The percentage of time spent below 4.0 mmol/L decreased from 9% to 0.9% in scenario 1 and 9.5% to 1.1% in scenario 2.

CONCLUSIONS

Results indicate that the proposed algorithm has the potential to improve glucose control in people with type 1 diabetes using the hybrid artificial pancreas. The proposed algorithm is a key in making the hybrid artificial pancreas adaptive for the long-term real life outpatient studies.

Restoration of Hypoglycemia Awareness Alters Brain Activity in Type 1 Diabetes

OBJECTIVE

Impaired awareness of hypoglycemia (IAH) in type 1 diabetes (T1D) is a major risk factor for severe hypoglycemia (SH) and is associated with atypical responses to hypoglycemia in brain regions involved in arousal, decision making, and memory. Whether restoration of hypoglycemia awareness alters these responses is unknown. We sought to investigate the impact of awareness restoration on brain responses to hypoglycemia.

RESEARCH DESIGN AND METHODS

Twelve adults with T1D and IAH underwent pseudocontinuous arterial spin labeling functional MRI during a hypoglycemic clamp (5-2.6 mmol/L) before and after a hypoglycemia avoidance program of structured education (Dose Adjustment for Normal Eating), specialist support, and sensor-augmented pump therapy (Medtronic MiniMed 640G). Hypoglycemic cerebral blood flow (CBF) responses were compared pre- and postintervention using predefined region-of-interest analysis of the thalamus, anterior cingulate cortex (ACC), orbitofrontal cortex (OFC), and hippocampus.

RESULTS

Postintervention, Gold and Clarke scores fell (6.0 ± 1.0 to 4.0 ± 1.6, P = 0.0002, and 5.7 ± 1.7 to 3.4 ± 1.8, P = 0.0008, respectively), SH rates reduced (1.5 ± 2 to 0.3 ± 0.5 episodes per year, P = 0.03), hypoglycemic symptom scores increased (18.8 ± 6.3 to 27.3 ± 12.7, P = 0.02), and epinephrine responses did not change (P = 0.2). Postintervention, hypoglycemia induced greater increases in ACC CBF (P = 0.01, peak voxel coordinates [6, 40, -2]), while thalamic and OFC activity did not change.

CONCLUSIONS

Increased blood flow is seen within brain pathways involved in internal self-awareness and decision making (ACC) after restoration of hypoglycemia awareness, suggesting partial recovery of brain responses lost in IAH. Resistance of frontothalamic networks, involved in arousal and emotion processing, may explain why not all individuals with IAH achieve awareness restoration with education and technology alone.

A Comparison of Validated Methods Used to Assess Impaired Awareness of Hypoglycaemia in Type 1 Diabetes: An Observational Study

INTRODUCTION

Clarke, Gold and Pedersen are validated methods to assess awareness of hypoglycaemia. Identifying impaired awareness of hypoglycaemia (IAH) is critical for supporting people with structured education and diabetes technologies, to reduce harm of hypoglycaemia. This study compares the Clarke score, Gold score and Pedersen methods and their correlations with features of hypoglycaemia unawareness and patient characteristics, to evaluate the accuracy of the methods in identifying IAH.

METHODS

This retrospective, observational questionnaire-based study collected routine clinical data from 100 people with type 1 diabetes. The questionnaire included the three validated scoring methods, frequency of severe and nocturnal hypoglycaemia, knowledge and worry of hypoglycaemia and hypoglycaemia symptom scores using the Edinburgh Hypoglycaemia Scale. Data were analysed for IAH prevalence and the associations with features of IAH. The concordance of Clarke, Gold and Pedersen methods was evaluated using Spearman's correlation coefficient.

RESULTS

The prevalence of IAH in this cohort identified by Clarke, Gold and Pedersen methods was 18%, 19% and 61% respectively. The mean autonomic symptom score in people with IAH was significantly reduced using the Clarke method (P = 0.0002) but not on Gold (P = 0.12) and Pedersen methods (P = 0.79). For people with IAH assessed using the Clarke method, scores for night-time worry regarding hypoglycaemia (P = 0.04) and self-reported frequency of nocturnal hypoglycaemia (P = 0.001) were increased. Spearman's correlation coefficients between Pedersen and Clarke and Pedersen and Gold were R_s = 0.555 (P < 0.001) and R_s = 0.645 (P < 0.001) respectively. A moderate association was observed between Clarke and Gold R_s = 0.5669 (P < 0.001).

CONCLUSION

Whilst Clarke and Gold methods determined a similar prevalence of IAH, people identified with IAH assessed by the Clarke method had a significant association with the features and characteristics of IAH, including reduced autonomic symptoms. This study suggests that performing more than one score is important for a reliable risk assessment of IAH.

Sustained Impact of Real-time Continuous Glucose Monitoring in Adults With Type 1 Diabetes on Insulin Pump Therapy: Results After the 24-Month RESCUE Study

OBJECTIVE

In recent years, a growing number of people with type 1 diabetes gained access to real-time continuous glucose monitoring (rtCGM). Long-term benefits of rtCGM are unclear because of a lack of large studies of long duration. We evaluated whether real-world rtCGM use up to 24 months offered benefits, particularly in those living with impaired awareness of hypoglycemia (IAH).

RESEARCH DESIGN AND METHODS

This 24-month, prospective, observational cohort study followed 441 adults with insulin pumps receiving full reimbursement for rtCGM. Forty-two percent had IAH. The primary end point was evolution of HbA_1c, with secondary end points change in acute hypoglycemia complications, diabetes-related work absenteeism, and quality of life scores. Additionally, we evaluated whether people could achieve glycemic consensus targets during follow-up.

RESULTS

After 24 months, HbA_1c remained significantly lower compared with baseline (7.64% [60 mmol/mol] vs. 7.37% [57 mmol/mol], P < 0.0001). Sustained benefits were also observed for the score on the hypoglycemia fear survey and hypoglycemia-related acute complications irrespective of hypoglycemia awareness level. People with IAH had the strongest improvement, especially for severe hypoglycemia (862 events in the year before vs. 119 events per 100 patient-years in the 2nd year, P < 0.0001). Over 24 months, more people were able to meet hypoglycemia consensus targets at the expense of slightly fewer people achieving hyperglycemia consensus targets. Furthermore, the number of people with HbA_1c <7% (<53 mmol/mol) without severe hypoglycemia events more than doubled (11.0% vs. 25.4%, P < 0.0001).

CONCLUSIONS

Use of rtCGM led to sustained improvements in hypoglycemia-related glucose control over 24 months. Lower fear of hypoglycemia, fewer acute hypoglycemia-related events, and fewer diabetes-related days off from work were observed, particularly in those with IAH.

Predictors of Recurrent Severe Hypoglycemia in Adults With Type 1 Diabetes and Impaired Awareness of Hypoglycemia During the HypoCOMPaSS Study

OBJECTIVE

The HypoCOMPaSS study was designed to test the hypothesis that successful avoidance of biochemical hypoglycemia without compromising overall glycemic control would restore sufficient hypoglycemia awareness to prevent recurrent severe hypoglycemia in the majority of participants with established type 1 diabetes. Before starting the study, we planned to investigate associations between baseline characteristics and recurrent severe hypoglycemia over 2 years' follow-up.

RESEARCH DESIGN AND METHODS

A total of 96 adults with type 1 diabetes and impaired awareness of hypoglycemia participated in a 24-week 2 × 2 factorial randomized controlled trial comparing insulin delivery and glucose monitoring modalities, with the goal of rigorous biochemical hypoglycemia avoidance. The analysis included 71 participants who had experienced severe hypoglycemia in the 12-month prestudy with confirmed absence (complete responder) or presence (incomplete responder) of severe hypoglycemia over 24 months' follow-up.

RESULTS

There were 43 (61%) complete responders and 28 (39%) incomplete responders experiencing mean ± SD 1.5 ± 1.0 severe hypoglycemia events/person-year. At 24 months, incomplete responders spent no more time with glucose ≤3 mmol/L (1.4 ± 2.1% vs. 3.0 ± 4.8% for complete responders; P = 0.26), with lower total daily insulin dose (0.45 vs. 0.58 units/24 h; P = 0.01) and greater impairment of hypoglycemia awareness (Clarke score: 3.8 ± 2.2 vs. 2.0 ± 1.9; P = 0.01). Baseline severe hypoglycemia rate (16.9 ± 16.3 vs. 6.4 ± 10.8 events/person-year; P = 0.002) and fear of hypoglycemia were higher in incomplete responders. Peripheral neuropathy was more prevalent in incomplete responders (11 [39%] vs. 2 [4.7%]; P < 0.001) with a trend toward increased autonomic neuropathy.

CONCLUSIONS

Recurrent severe hypoglycemia was associated with higher preintervention severe hypoglycemia rate, fear of hypoglycemia, and concomitant neuropathy.

Impaired Awareness of Hypoglycemia Disrupts Blood Flow to Brain Regions Involved in Arousal and Decision Making in Type 1 Diabetes

OBJECTIVE

Impaired awareness of hypoglycemia (IAH) affects one-quarter of adults with type 1 diabetes and significantly increases the risk of severe hypoglycemia. Differences in regional brain responses to hypoglycemia may contribute to the susceptibility of this group to problematic hypoglycemia. This study investigated brain responses to hypoglycemia in hypoglycemia aware (HA) and IAH adults with type 1 diabetes, using three-dimensional pseudo-continuous arterial spin labeling (3D pCASL) functional MRI to measure changes in regional cerebral blood flow (CBF).

RESEARCH DESIGN AND METHODS

Fifteen HA and 19 IAH individuals underwent 3D pCASL functional MRI during a two-step hyperinsulinemic glucose clamp. Symptom, hormone, global, and regional CBF responses to hypoglycemia (47 mg/dL [2.6 mmol/L]) were measured.

RESULTS

In response to hypoglycemia, total symptom score did not change in those with IAH (P = 0.25) but rose in HA participants (P < 0.001). Epinephrine, cortisol, and growth hormone responses to hypoglycemia were lower in the IAH group (P < 0.05). Hypoglycemia induced a rise in global CBF (HA P = 0.01, IAH P = 0.04) but was not different between groups (P = 0.99). IAH participants showed reduced regional CBF responses within the thalamus (P = 0.002), right lateral orbitofrontal cortex (OFC) (P = 0.002), and right dorsolateral prefrontal cortex (P = 0.036) and a lesser decrease of CBF in the left hippocampus (P = 0.023) compared with the HA group. Thalamic and right lateral OFC differences survived Bonferroni correction.

CONCLUSIONS

Responses to hypoglycemia of brain regions involved in arousal, decision making, and reward are altered in IAH. Changes in these pathways may disrupt IAH individuals' ability to recognize hypoglycemia, impairing their capacity to manage hypoglycemia effectively and benefit fully from conventional therapeutic pathways to restore awareness.

Prepregnancy care in women with type 1 diabetes improves HbA1c and glucose variability without worsening hypoglycaemia time and awareness: Glycaemic variability during prepregnancy care

AIMS

To evaluate the impact of a prepregnancy care (PPC) programme, beyond HbA_1c, on hypoglycaemia awareness and glycaemic variability (GV).

METHODS

Prospective pilot study. We selected women with Type 1 diabetes who initiated a PPC programme with normal hypoglycaemia awareness (n = 24). Hypoglycaemia awareness, hypoglycaemic events and GV derived from masked-continuous glucose monitoring were evaluated in the first visit and within 2 weeks after pregnancy confirmation.

RESULTS

The duration was 16.5 ± 13.0 months. HbA_1c significantly decreased (-0.8 ± 0.7; p < 0.001). The Clarke score increased (0[0-1] vs. 1[0-2] points, p = 0.164), 2 out of 24 were reclassified as having impaired awareness of hypoglycaemia and 2 presented severe hypoglycaemia. GV decreased: standard deviation (p = 0.008), coefficient of variation (p = 0.021), mean amplitude of glycaemic excursions (p = 0.007), average daily risk range (p < 0.001), J-index (p = 0.010), high blood glucose index (HBGI) (p = 0.004), continuous overall net glycaemic action (CONGA) (p = 0.018), mean of daily differences (p = 0.045) and glycaemic risk assessment diabetes equation (p = 0.012). Final HbA_1c was associated with baseline J-index, CONGA and HBGI (β = 0.535, β = 0.466, β = 0.534, respectively; p < 0.05).

CONCLUSIONS

A PPC programme improved HbA_1c as well as GV with no significant impact on hypoglycaemia awareness. Moreover, GV could help to identify women less likely to achieve glycaemic targets. Larger studies are needed to confirm these results.

Efficacy and safety of suspend-before-low insulin pump technology in hypoglycaemia-prone adults with type 1 diabetes (SMILE): an open-label randomised controlled trial

BACKGROUND

Hypoglycaemia unawareness and severe hypoglycaemia can increase fear of hypoglycaemia and the risk of subsequent hypoglycaemic events. We aimed to assess the safety and efficacy of insulin pump therapy with integrated continuous glucose monitoring (CGM) and a suspend-before-low feature (Medtronic MiniMed 640G with SmartGuard) in hypoglycaemia-prone adults with type 1 diabetes.

METHODS

SMILE was an open-label randomised controlled trial done in people aged 24-75 years with type 1 diabetes for 10 years or longer, HbA_1c values of 5·8-10·0% (40-86 mmol/mol), and at high risk of hypoglycaemia (recent severe hypoglycaemia or hypoglycaemia unawareness defined by a Clarke or Gold score ≥4). Participants were enrolled from 16 centres (eg, clinics, hospitals, or university medical centres) in Canada, France, Italy, the Netherlands, and the UK. After baseline run-in phase (2 weeks), participants were randomly assigned to the MiniMed 640G pump (continuous subcutaneous insulin infusion) with self-monitoring of blood glucose (control group) or to the MiniMed 640G system with the suspend-before-low feature enabled (intervention group), for 6 months. The study statistician analysing the data was masked to group assignment until final database lock; because of the nature of the intervention, participants and treating clinicians could not be masked to group assignment. The primary outcome was the mean number of sensor hypoglycaemic events, defined as 55 mg/dL (3·1 mmol/L) or lower, and was analysed on an intention-to-treat basis in all randomly assigned participants. This trial is registered with ClinicalTrials.gov, number NCT02733991, and is completed.

FINDINGS

Between Dec 7, 2016, and March 27, 2018, 153 participants with a mean age 48·2 [12·4] years were randomly assigned: 77 to the control group (mean age 47·4 [12·5] years) and 76 to the intervention group (mean age 49·0 [12·2] years). After 6 months, the intervention group had significantly fewer hypoglycaemic events per participant per week (1·1 [SD 1·2] vs 4·1 [3·4] mean events, model-based treatment effect -2·9 [95% CI -3·5 to -2·3]; p<0·0001) and fewer severe hypoglycaemic events (instances requiring third-party assistance with carbohydrate or glucagon administration, or other resuscitative actions) overall (three vs 18; p=0·0036). The most common adverse events were hypoglycaemia (observed in ten [13%] of 77 participants in the control group vs four [5%] of 76 in the intervention group) and hyperglycaemia (observed in seven [9%] of 77 vs seven [9%] of 76). No serious adverse device effects or episodes of diabetic ketoacidosis were reported.

INTERPRETATION

Insulin pump therapy with integrated CGM and a suspend-before-low feature reduced the frequency of sensor hypoglycaemic and severe hypoglycaemic events in hypoglycaemia-prone adults compared with use of continuous subcutaneous insulin infusion without real-time CGM. These results suggest that this technology could be beneficial in this high-risk population.

FUNDING

Medtronic International Trading Sàrl and Medtronic Canada.

Asymptomatic hypoglycaemia in Type 1 diabetes: incidence and risk factors

AIM

The epidemiology of asymptomatic (silent) hypoglycaemia is not well-described. We investigated incidence and risk factors for asymptomatic hypoglycaemia in Type 1 diabetes.

METHODS

A cohort of 153 people with Type 1 diabetes participated in 6 days of blinded continuous glucose monitoring (CGM) and recording of hypoglycaemia symptoms. At entry, hypoglycaemia awareness was classified (by three different methods) and HbA_1c and C-peptide were measured. Hypoglycaemic episodes were defined as interstitial glucose ≤ 3.9 mmol/l (IG_3.9 ) or ≤ 3.0 mmol/l (IG_3.0 ) for ≥ 15 min, and were considered asymptomatic if no hypoglycaemic symptoms were reported.

RESULTS

At thresholds IG_3.9 and IG_3.0 , the incidence rates of hypoglycaemic episodes were 5.0 (7.9) [median (IQR)] and 1.3 (3.4) episodes/person-week, respectively. Three-quarters of episodes were asymptomatic. In total, 77% and 52% of participants experienced one or more episode of asymptomatic hypoglycaemia at IG_3.9 and IG_3.0 [3.0 (6.2) and 1.0 (2.3) asymptomatic episodes/person-week]. At multivariate analysis, reduced awareness was positively associated with asymptomatic hypoglycaemia, particularly nocturnal events, and negatively with symptomatic hypoglycaemia. High insulin dose was associated with increased risk of both asymptomatic and symptomatic hypoglycaemia, whereas low HbA_1c and long diabetes duration were risk factors only for symptomatic hypoglycaemia.

CONCLUSIONS

Asymptomatic hypoglycaemia constitutes the majority of hypoglycaemic events in Type 1 diabetes. Reduced hypoglycaemia awareness and high insulin dose are risk factors for asymptomatic hypoglycaemia but other conventional risk factors for severe hypoglycaemia do not correlate with risk of asymptomatic episodes.

Role of continuous glucose monitoring in the management of glycogen storage disorders

Management of liver glycogen storage diseases (GSDs) primarily involves maintaining normoglycemia through dietary modifications and regular glucose monitoring. Self-monitoring of blood glucose is typically done 3-6 times per day, and may not sufficiently capture periods of asymptomatic hypoglycemia, particularly during sleep. Continuous glucose monitoring systems (CGMS) provide 24-h continuous glucose data and have been used effectively in diabetes mellitus to monitor metabolic control and optimize treatment. This is a relatively new approach in GSDs with only a handful of studies exploring this modality. In this study we used Dexcom CGMS to study the glycemic profile of 14 pediatric and six adult patients with GSD I, III, and IX. A total of 176 days of CGMS data were available. The CGMS was found to be a reliable tool in monitoring glucose levels and trends at all times of the day with good concordance with finger-stick glucose values. This study revealed that in addition to overnight hypoglycemia, CGMS can uncover previously undetected, subclinical, low glucose levels during daytime hours. Additionally, the CGMS detected daytime and overnight hyperglycemia, an often overlooked concern in liver GSDs. The CGMS with concurrent dietary adjustments made by a metabolic dietitian improved metabolic parameters and stabilized blood glucose levels. The CGMS was found to be a safe, effective, and reliable method for optimizing treatment in patients with GSD I, III, and IX.

Hypoglycemic Exposure and Risk of Asymptomatic Hypoglycemia in Type 1 Diabetes Assessed by Continuous Glucose Monitoring

CONTEXT

Recurrent hypoglycemia promotes impaired awareness, resulting in an increased risk for asymptomatic hypoglycemia. However, there are no firm data on the frequency of hypoglycemia in daily life needed to initiate this vicious cycle or the role of asymptomatic hypoglycemia.

OBJECTIVE

To explore the association between hypoglycemic exposure and proportion of asymptomatic hypoglycemia and relation to risk for severe hypoglycemia.

DESIGN

Prospective observational trial.

SETTING

Outpatient clinic.

PATIENTS

One hundred fifty-three unselected patients with type 1 diabetes mellitus (T1D).

INTERVENTION

Six days of blinded continuous glucose monitoring and recording of hypoglycemia symptoms.

MAIN OUTCOME MEASURE

Proportion of asymptomatic hypoglycemic events (glucose level ≤70 mg/dL).

RESULTS

Patients were grouped by the number of hypoglycemic events during the recording period (group 1: one event; group 2: two to three events; group 3: four to six events; group 4: seven or more events), and fractions of asymptomatic events were calculated. Across the four groups, the fraction of asymptomatic hypoglycemia increased: 57% in group 1, 61% in group 2, 65% in group 3, and 80% in group 4 (P < 0.001). Higher fraction of asymptomatic hypoglycemia was positively associated with risk for severe hypoglycemia (incidence rate ratio, 1.3; 95% confidence interval, 1.1 to 1.5; P = 0.003). Group 4 consisted of patients characterized by classic risk factors of severe hypoglycemia (longer duration of diabetes, lower hemoglobin A1c, and more frequent impaired awareness of hypoglycemia).

CONCLUSIONS

Patients with T1D with hypoglycemic rates corresponding to daily exposure had an increased fraction of asymptomatic events, which was positively associated with risk for severe hypoglycemia; therefore, such patients deserve particular attention in clinical practice.

Hypoglycaemia in type 1 diabetes: technological treatments, their limitations and the place of psychology

Advances in technology allowing improved insulin delivery and glucose monitoring can significantly reduce the burden of hypoglycaemia when used appropriately. However, limitations of the current technology, and the skills, commitment and motivation required to use them, mean that it does not work for all people. Education and informed professional support are key to success. In the context of problematic hypoglycaemia, data suggest that newer technology has lower efficacy and uptake in those with most need. Identifying the causes of hypoglycaemia and understanding some of the underlying behavioural drivers may prove useful and psycho-educational strategies may be effective in selected individuals. Ultimately, as in many spheres of medicine, successful management of problematic hypoglycaemia depends upon matching the right treatment to the right individual.

Clinical and Cost Implications of Insulin Degludec in Patients with Type 1 Diabetes and Problematic Hypoglycemia: A Quality Improvement Project

INTRODUCTION

To assess the real-life clinical benefits and cost implications of switching from another basal insulin to insulin degludec (degludec) in patients with type 1 diabetes (T1D) on basal-bolus regimens with recurrent hypoglycemia and/or hypoglycemia unawareness.

METHODS

Patients with T1D who were aged ≥ 18 years, were on a basal-bolus regimen, and had switched to degludec plus bolus insulin for at least 6 months were included. Patients had to have switched to degludec as a result of recurrent hypoglycemia and/or hypoglycemia unawareness.

RESULTS

Six months of follow-up data were available for 42 patients. At 6 months, there was a significant reduction in median (interquartile range) HbA_1c, from 8.6 (8.0-9.3)% [70 (64-78) mmol/mol] to 8.4 (7.9-8.9)% [68 (63-74) mmol/mol]; p < 0.05. Median daily basal insulin dose reduced significantly from 30.0 (14.7-45.0) to 25.5 (14.0-30.2) units; p < 0.0001. Data from hospital records showed reductions in the frequency of episodes of severe hypoglycemia from eight in the 6 months preceding degludec initiation to two in the 6 months following initiation. In the same period, diabetic ketoacidosis (DKA) episodes reduced from two before degludec initiation to no episodes after initiation. No patients reported worsening treatment satisfaction after switching to degludec. Considering the reductions in the basal dose required and the frequency of hypoglycemia episodes, we estimate that switching such patients to degludec from other basal insulins could provide significant savings in direct healthcare costs.

CONCLUSION

In patients with T1D, switching to degludec was associated with an improvement in HbA_1c and reductions in basal insulin dose, severe hypoglycemia, and DKA. When used in appropriate patients, degludec could lead to significant cost savings.

FUNDING

Novo Nordisk.

Effect of Insulin Analogs on Frequency of Non-Severe Hypoglycemia in Patients with Type 1 Diabetes Prone to Severe Hypoglycemia: Much Higher Rates Detected by Continuous Glucose Monitoring than by Self-Monitoring of Blood Glucose-The HypoAna Trial

BACKGROUND

Hypoglycemia is an increasingly important endpoint in clinical diabetes trials. The assessment of hypoglycemia should therefore be as complete as possible. Blinded continuous glucose monitoring (CGM) provides an improved opportunity to capture asymptomatic and nocturnal events. Here we report results from the HypoAna trial comparing all-analog-insulin therapy (aspart/detemir) with all-human-insulin therapy (neutral protamine Hagedorn/regular) on non-severe hypoglycemia (symptomatic and asymptomatic hypoglycemia) as assessed by blinded CGM and compared with data obtained by self-monitoring of blood glucose (SMBG) in patients with type 1 diabetes and recurrent severe hypoglycemia.

METHODS

Fifty-three patients completed a substudy of 4 × 3 days of blinded CGM. CGM traces were reviewed for hypoglycemic events lasting 15 min or longer.

RESULTS

At the threshold ≤3.9 mmol/L, the per-protocol analysis demonstrated a 40% rate reduction (95% confidence interval [CI] 20%-60%; P = 0.002) in nocturnal non-severe hypoglycemia during analog treatment, mainly due to a 40% rate reduction (95% CI 0%-70%; P = 0.03) of nocturnal asymptomatic hypoglycemia. Similar nonsignificant trends were seen at the glucose threshold ≤3.0 mmol/L. Overall CGM-detected that nocturnal asymptomatic hypoglycemia ≤3.9 mmol/L was ∼17 times more frequent than SMBG-detected episodes (52 vs. 3 events/patient-year). This translates into a time needed to treat one patient with insulin analogs to prevent one episode that is 34 times shorter using CGM data than SMBG data (1.4 vs. 47 weeks).

CONCLUSIONS

Capturing hypoglycemic events by the conventional method of SMBG in patients with impaired awareness reveals only a limited number of events. Blinded CGM can provide more complete data, particularly in terms of asymptomatic and nocturnal events.

The relation between HbA1c and hypoglycemia revisited; a secondary analysis from an intervention trial in patients with type 1 diabetes and impaired awareness of hypoglycemia

AIMS

We aimed to re-assess the previously shown but recently disputed association between HbA1c and severe hypoglycemia.

METHODS

52 Patients with T1D and IAH participated in an earlier reported randomized, crossover trial with two 16-week intervention periods comparing continuous glucose monitoring (CGM) with self-monitoring of blood glucose (SMBG). In this previous study, time spent in normoglycemia (the primary outcome), was improved by 9.6% (p<0.0001). We performed post-hoc analyses using a zero-inflated Poisson regression model to assess the relationship between severe hypoglycemia and HbA1c, glucose variability and duration of diabetes.

RESULTS

During SMBG use, HbA1c and the number of severe hypoglycemic events were negatively associated (OR 0.20 [95% CI 0.09 to 0.44]). During CGM use, this relationship showed an odds ratio of 0.65 (95% CI 0.42 to 1.01). There was no significant relationship between glucose variability or duration of diabetes and severe hypoglycemia.

CONCLUSIONS

In patients with T1D and IAH, treated with standard SMBG, a negative association exists between HbA1c and the number of severe hypoglycemic events. Thus, reaching target HbA1c values still comes with a higher risk of severe hypoglycemia. CGM weakens this association, suggesting CGM enables patients to reach their target HbA1c more safely.

Random non-fasting C-peptide testing can identify patients with insulin-treated type 2 diabetes at high risk of hypoglycaemia

AIMS/HYPOTHESIS

The aim of this study was to determine whether random non-fasting C-peptide (rCP) measurement can be used to assess hypoglycaemia risk in insulin-treated type 2 diabetes.

METHODS

We compared continuous glucose monitoring-assessed SD of blood glucose and hypoglycaemia duration in 17 patients with insulin-treated type 2 diabetes and severe insulin deficiency (rCP < 200 pmol/l) and 17 matched insulin-treated control patients with type 2 diabetes but who had preserved endogenous insulin (rCP > 600 pmol/l). We then assessed the relationship between rCP and questionnaire-based measures of hypoglycaemia in 256 patients with insulin-treated type 2 diabetes and a comparison group of 209 individuals with type 1 diabetes.

RESULTS

Continuous glucose monitoring (CGM)-assessed glucose variability and hypoglycaemia was greater in individuals with rCP < 200 pmol/l despite similar mean glucose. In those with low vs high C-peptide, SD of glucose was 4.2 (95% CI 3.7, 4.6) vs 3.0 (2.6, 3.4) mmol/l (p < 0.001). In the low-C-peptide vs high-C-peptide group, the proportion of individuals experiencing sustained hypoglycaemia ≤ 4 mmol/l was 94% vs 41% (p < 0.001), the mean rate of hypoglycaemia was 5.5 (4.4, 6.7) vs 2.1 (1.4, 2.9) episodes per person per week (p = 0.004) and the mean duration was 630 (619, 643) vs 223 (216, 230) min per person per week (p = 0.01). Hypoglycaemia ≤ 3 mmol/l was infrequent in individuals with preserved C-peptide (1.8 [1.2, 2.6] episodes per person per week vs 0.4 [0.1, 0.8] episodes per person per week for low vs high C-peptide, p = 0.04) and only occurred at night. In a population-based cohort with insulin-treated type 2 diabetes, self-reported hypoglycaemia was twice as frequent in those with rCP < 200 pmol/l (OR 2.0, p < 0.001) and the rate of episodes resulting in loss of consciousness or seizure was five times higher (OR 5.0, p = 0.001). The relationship between self-reported hypoglycaemia and C-peptide was similar in individuals with type 1 and type 2 diabetes.

CONCLUSIONS/INTERPRETATION

Low rCP is associated with increased glucose variability and hypoglycaemia in patients with insulin-treated type 2 diabetes and represents a practical, stable and inexpensive biomarker for assessment of hypoglycaemia risk.

Outpatient 60-hour day-and-night glucose control with dual-hormone artificial pancreas, single-hormone artificial pancreas, or sensor-augmented pump therapy in adults with type 1 diabetes: An open-label, randomised, crossover, controlled trial

AIMS

To assess whether the dual-hormone (insulin and glucagon) artificial pancreas reduces hypoglycaemia compared to the single-hormone (insulin alone) artificial pancreas in outpatient settings during the day and night.

MATERIAL AND METHODS

In a randomized, three-way, crossover trial we compared the dual-hormone artificial pancreas, the single-hormone artificial pancreas and sensor-augmented pump therapy (control) in 23 adults with type 1 diabetes. Each intervention was applied from 8 AM Day 1 to 8 PM Day 3 (60 hours) in outpatient free-living conditions. The primary outcome was time spent with sensor glucose levels below 4.0 mmol/L. A P value of less than .017 was regarded as significant.

RESULTS

The median difference between the dual-hormone system and the single-hormone system was -2.3% (P = .072) for time spent below 4.0 mmol/L, -1.3% (P = .017) for time below 3.5 mmol/L, and -0.7% (P = .031) for time below 3.3 mmol/L. Both systems reduced (P < .017) hypoglycaemia below 4.0, 3.5 and 3.3 mmol/L compared to control therapy, but reductions were larger with the dual-hormone system than with the single-hormone system (medians -4.0% vs -3.4% for 4.0 mmol/L; -2.7% vs -2.2% for 3.5 mmol/L; and -2.2% vs -1.2% for 3.3 mmol/L). There were 34 hypoglycaemic events (<3.0 mmol/L for 20 minutes) with control therapy, 14 with the single-hormone system and 6 with the dual-hormone system. These differences in hypoglycaemia were observed while mean glucose level was low and comparable in all interventions (P = NS).

CONCLUSIONS

The dual-hormone artificial pancreas had the lowest risk of hypoglycaemia, but the differences were not statistically significant. Larger studies are needed.

Who Should Be Considered for Islet Transplantation Alone?

PURPOSE OF REVIEW

Episodic hypoglycemia is an almost inevitable consequence of exogenous insulin treatment of type 1 diabetes, and in up to 30% of patients, this can lead to impaired awareness of hypoglycemia. This predisposes to recurrent severe hypoglycemia and has a huge impact on quality of life. Although many patients can get resolution of severe hypoglycemia through novel education and technology, some patients continue to have ongoing life-threatening hypoglycemia. Islet transplantation offers an alternative therapeutic option for these patients, in whom these conventional approaches have been unsuccessful. This review discusses the selection process of identifying suitable candidates based on recent clinical data.

RECENT FINDINGS

Results from studies of islet transplantation suggest the optimal recipient characteristics for successful islet transplantation include age >35 years, insulin requirements <1.0/kg, and weight < 85 kg. Islet transplantation can completely resolve hypoglycemia and near-normalize glucose levels, achieving insulin independence for a limited period of time in up to 40% of patients. The selection of appropriate candidates, optimizing donor selection, the use of an optimized protocol for islet cell extraction, and immunosuppression therapy have been proved to be the key criteria for a favorable outcome in islet transplantation.

Self-reported frequency, severity of, and awareness of hypoglycemia in type 2 diabetes patients in Turkey

OBJECTIVES

Hypoglycemia is a common side effect of insulin therapy in type 1 and type 2 diabetes. Limited data exist on the frequency of hypoglycemic events in type 2 diabetic patients in Turkey. Our study investigated self-reported hypoglycemic events and awareness of hypoglycemia in Turkish patients with type 2 diabetes.

METHODS

People with type 2 diabetes older than 18 years of age were recruited from the two university hospital diabetes clinics. The frequency and severity of hypoglycemia and awareness of hypoglycemia during the preceding year were determinated using questionnaires by the face-to-face interview method.

RESULTS

In this study of 187 patients with type 2 diabetes, 83.4% had impaired awareness of their hypoglycemia, and 62% reported that they had missed some of the symptoms of hypoglycemia. Of the patients reporting hypoglycemic symptoms and severity level, 84.1% experienced mild hypoglycemia, 60% moderate, and 15.5% severe hypoglycemia in the past year. No significant association was made between hypoglycemia awareness and age, body-mass index (BMI), years of diabetes, dose of insulin, duration of insulin use, number of meals, or amount of snacking. A significant correlation was found between A1c levels and hypoglycemia awareness and severity of hypoglycemia. A significant correlation was found between dose of insulin, amount of snacking, and severity of hypoglycemia. No significant association was made between severity of hypoglycemia and age, BMI, years of diabetes, duration of insulin use, or the number of meals. However, the group with severe hypoglycemia had diabetes longer, and the average daily dose of insulin use was higher than in other groups.

CONCLUSIONS

According to the study results, the percentage of patients with impaired awareness of hypoglycemia is high, and 62% of patients reported that they had missed some of the symptoms of hypoglycemia in type 2 diabetes. In addition, the percentage of severe hypoglycemic events is not low. Impaired awareness of hypoglycemia is a major risk factor for severe hypoglycemic events. Patients should be educated about the danger of hypoglycemia. Education should be improved, and a determined attempt should be made to eradicate the problem.

Continuous glucose monitoring for patients with type 1 diabetes and impaired awareness of hypoglycaemia (IN CONTROL): a randomised, open-label, crossover trial

BACKGROUND

Patients with type 1 diabetes who have impaired awareness of hypoglycaemia have a three to six times increased risk of severe hypoglycaemia. We aimed to assess whether continuous glucose monitoring (CGM) improves glycaemia and prevents severe hypoglycaemia compared with self-monitoring of blood glucose (SMBG) in this high-risk population.

METHODS

We did a randomised, open-label, crossover trial (IN CONTROL) at two medical centres in the Netherlands. Eligible participants were patients diagnosed with type 1 diabetes according to American Diabetes Association criteria, aged 18-75 years, with impaired awareness of hypoglycaemia as confirmed by a Gold score of at least 4, and treated with either continuous subcutaneous insulin infusion or multiple daily insulin injections and doing at least three SMBG measurements per day. After screening, re-education about diabetes management, and a 6-week run-in phase (to obtain baseline CGM data), we randomly assigned patients (1:1) with a computer-generated allocation sequence (block size of four) to either 16 weeks of CGM followed by 12 weeks of washout and 16 weeks of SMBG, or 16 weeks of SMBG followed by 12 weeks of washout and 16 weeks of CGM (where the SMBG phase was the control). During the CGM phase, patients used a real-time CGM system consisting of a Paradigm Veo system with a MiniLink transmitter and an Enlite glucose sensor (Medtronic, CA, USA). During the SMBG phase, patients were equipped with a masked CGM device, consisting of an iPro 2 continuous glucose monitor and an Enlite glucose sensor, which does not display real-time glucose values. The number of SMBG measurements per day and SMBG systems were not standardised between patients, to mimic real-life conditions. During both intervention periods, patients attended follow-up visits at the centres each month and had telephone consultations 2 weeks after each visit inquiring about adverse events, episodes of hypoglycaemia, etc. The primary endpoint was the mean difference in percentage of time spent in normoglycaemia (4-10 mmol/L) over the total intervention periods, analysed on an intention-to-treat basis. Severe hypoglycaemia (requiring third party assistance) was a secondary endpoint. This trial is registered with ClinicalTrials.gov, number NCT01787903.

FINDINGS

Between March 4, 2013, and Feb 9, 2015, we recruited and randomly assigned 52 patients to either the CGM-SMBG sequence (n=26) or the SMBG-CGM sequence (n=26). The last patient visit was on March 21, 2016. Time spent in normoglycaemia was higher during CGM than during SMBG: 65·0% (95% CI 62·8-67·3) versus 55·4% (53·1-57·7; mean difference 9·6%, 95% CI 8·0-11·2; p<0·0001), with reductions in both time spent in hypoglycaemia (ie, blood glucose ≤3·9 mmol/L [6·8% vs 11·4%, mean difference 4·7%, 3·4-5·9; p<0·0001]) and time spent in hyperglycaemia (ie, blood glucose >10 mmol/L [28·2% vs 33·2%, mean difference 5·0%, 3·1-6·9; p<0·0001]). During CGM, the number of severe hypoglycaemic events was lower (14 events vs 34 events, p=0·033). Five serious adverse events other than severe hypoglycaemia occurred during the trial, but all were deemed unrelated to the trial intervention. Additionally, no mild to moderate adverse events were related to the trial intervention.

INTERPRETATION

CGM increased time spent in normoglycaemia and reduced severe hypoglycaemia in patients with type 1 diabetes and impaired awareness of hypoglycaemia, compared with SMBG. Our results support the concept of using CGM in this high-risk population.

FUNDING

Eli Lilly and Sanofi.

Hypoglycemia and diabetes: increased need for awareness

Hypoglycemia is an abnormally low plasma glucose concentration that may expose individuals to potential harm. It is associated with treatment of type 1 diabetes and type 2 diabetes. Diabetes-related hypoglycemia may result in various complications, reduced quality of life, and increased costs. Hypoglycemia, therefore, impacts patient management and must be considered by primary healthcare practitioners at the forefront of diabetes care. This paper reviews the impact of hypoglycemia on patients and healthcare practitioners in the clinical setting. Recognizing hypoglycemia and its risk factors and identifying high-risk patients can assist with prevention and management. Prevention rather than treatment of hypoglycemia is preferable by individualizing glycemic goals, considering hypoglycemia risk factors, and continuing professional support. Education of patients and healthcare practitioners is also a key factor in hypoglycemia prevention. Although several newer-generation therapies and treatment strategies for type 2 diabetes have a lower risk of hypoglycemia than established agents, long-term safety data are currently lacking. Thus, choice of therapy is important, with hypoglycemic risk varying according to drug selection.

Hypoglycaemia in adults with insulin-treated diabetes in the UK: self-reported frequency and effects

AIM

Few real-life studies of non-severe (self-treated) hypoglycaemic events are available. This survey quantified the self-reported frequency of non-severe hypoglycaemia and its effects in adults with insulin-treated diabetes in the UK.

METHODS

Adults aged > 15 years with Type 1 diabetes or insulin-treated Type 2 diabetes completed ≤ 4 weekly questionnaires (7-day recall). Respondents with Type 2 diabetes were grouped by insulin regimen: basal-only, basal-bolus and 'other'.

RESULTS

Overall, 1038 respondents (466 with Type 1 diabetes, 572 with Type 2 diabetes) completed 3528 questionnaires. Mean numbers of non-severe events per week were 2.4 (Type 1 diabetes; median = 2) and 0.8 (Type 2 diabetes; median = 0); 23% and 26% of non-severe events occurred at night, respectively. Fatigue and reduced alertness were the commonest issues following events (78% and 51% of respondents, respectively). The effects of nocturnal events persisted longer than those of daytime events: Type 1 diabetes = 10.6 vs. 4.9 h (P = 0.0002); Type 2 diabetes = 15.3 vs. 5.1 h (P < 0.0001). In the week following an event, respondents' blood glucose measurements increased by 4.3 (Type 1 diabetes; 12% increment) and 4.2 (Type 2 diabetes; 21% increment) tests/week. In employed respondents, 20% of events caused work-time loss, more so following nocturnal (vs. daytime) hypoglycaemia: Type 1 diabetes = 2.7 vs. 1.1 h (P = 0.0184); Type 2 diabetes = 2.5 vs. 1.6 h (P = 0.1340). Most respondents rarely/never informed healthcare professionals about events (Type 1 diabetes = 82%, Type 2 diabetes = 69%).

CONCLUSIONS

Non-severe hypoglycaemia is common in adults with insulin-treated diabetes in the UK, with consequent health-related/economic effects. Communication about non-severe hypoglycaemia is limited and the burden of hypoglycaemia may be underestimated.

Risk Factors Associated With Severe Hypoglycemia in Older Adults With Type 1 Diabetes

OBJECTIVE

Severe hypoglycemia is common in older adults with long-standing type 1 diabetes, but little is known about factors associated with its occurrence.

RESEARCH DESIGN AND METHODS

A case-control study was conducted at 18 diabetes centers in the T1D Exchange Clinic Network. Participants were ≥60 years old with type 1 diabetes for ≥20 years. Case subjects (n = 101) had at least one severe hypoglycemic event in the prior 12 months. Control subjects (n = 100), frequency-matched to case subjects by age, had no severe hypoglycemia in the prior 3 years. Data were analyzed for cognitive and functional abilities, social support, depression, hypoglycemia unawareness, various aspects of diabetes management, C-peptide level, glycated hemoglobin level, and blinded continuous glucose monitoring (CGM) metrics.

RESULTS

Glycated hemoglobin (mean 7.8% vs. 7.7%) and CGM-measured mean glucose (175 vs. 175 mg/dL) were similar between case and control subjects. More case than control subjects had hypoglycemia unawareness: only 11% of case subjects compared with 43% of control subjects reported always having symptoms associated with low blood glucose levels (P < 0.001). Case subjects had greater glucose variability than control subjects (P = 0.008) and experienced CGM glucose levels <60 mg/dL for ≥20 min on 46% of days compared with 33% of days in control subjects (P = 0.10). On certain cognitive tests, case subjects scored worse than control subjects.

CONCLUSIONS

In older adults with long-standing type 1 diabetes, greater hypoglycemia unawareness and glucose variability are associated with an increased risk of severe hypoglycemia. A study to assess interventions to prevent severe hypoglycemia in high-risk individuals is needed.

Characterizing problematic hypoglycaemia: iterative design and preliminary psychometric validation of the Hypoglycaemia Awareness Questionnaire (HypoA-Q)

AIMS

To design and conduct preliminary validation of a measure of hypoglycaemia awareness and problematic hypoglycaemia, the Hypoglycaemia Awareness Questionnaire.

METHODS

Exploratory and cognitive debriefing interviews were conducted with 17 adults (nine of whom were women) with Type 1 diabetes (mean ± sd age 48 ± 10 years). Questionnaire items were modified in consultation with diabetologists/psychologists. Psychometric validation was undertaken using data from 120 adults (53 women) with Type 1 diabetes (mean ± sd age 44 ± 16 years; 50% with clinically diagnosed impaired awareness of hypoglycaemia), who completed the following questionnaires: the Hypoglycaemia Awareness Questionnaire, the Gold score, the Clarke questionnaire and the Problem Areas in Diabetes questionnaire.

RESULTS

Iterative design resulted in 33 items eliciting responses about awareness of hypoglycaemia when awake/asleep and hypoglycaemia frequency, severity and impact (healthcare utilization). Psychometric analysis identified three subscales reflecting 'impaired awareness', 'symptom level' and 'symptom frequency'. Convergent validity was indicated by strong correlations between the 'impaired awareness' subscale and existing measures of awareness: (Gold: rs =0.75, P < 0.01; Clarke: rs =0.76, P < 0.01). Divergent validity was indicated by weaker correlations with diabetes-related distress (Problem Areas in Diabetes: rs =0.25, P < 0.01) and HbA1c (rs =-0.05, non-significant). The 'impaired awareness' subscale and other items discriminated between those with impaired and intact awareness (Gold score). The 'impaired awareness' subscale and other items contributed significantly to models explaining the occurrence of severe hypoglycaemia and hypoglycaemia when asleep.

CONCLUSIONS

This preliminary validation shows the Hypoglycaemia Awareness Questionnaire has robust face and content validity; satisfactory structure; internal reliability; convergent, divergent and known groups validity. The impaired awareness subscale and other items contribute significantly to models explaining recall of severe and nocturnal hypoglycaemia. Prospective validation, including determination of a threshold to identify impaired awareness, is now warranted.

Severe Hypoglycemia and the Role of the Significant Other: Expert, Sentry, and Protector

PURPOSE

The purpose of the study was to gain a better understanding of what severe hypoglycemia means to significant others.

METHODS

Narrative inquiry methodology was utilized. In-depth interviews were conducted with 7 significant others of adults with type 1 diabetes about their experience with severe hypoglycemia. Interviews were recorded, transcribed verbatim, and then developed into narrated core stories through a process of selecting and organizing events and by describing the relationship among these events. This was followed by thematic analysis to reveal the shared narrative of significant others.

RESULTS

Episodes of severe hypoglycemia were found to turn the participants' lives upside down. The inability of the individual with diabetes to manage severe hypoglycemia required the significant other to detect and treat these episodes. The theme "managing disruption" captured how the significant others' role shifted from one of background support to an active, primary role in severe hypoglycemia management. They became (1) the expert by arming themselves with knowledge and skills to assist with the severe hypoglycemia episodes, (2) the sentry by becoming more vigilant and prepared for these episodes, and (3) the protector of the person with diabetes by shielding him or her from the vulnerable position that the severe hypoglycemia episodes placed one in.

CONCLUSIONS

This study highlights the important role that significant others play in the management of severe hypoglycemia. It also emphasizes the need for health care professionals to provide appropriate education and support.

Mechanisms of hypoglycemia unawareness and implications in diabetic patients

Hypoglycemia unawareness (HU) is defined at the onset of neuroglycopenia before the appearance of autonomic warning symptoms. It is a major limitation to achieving tight diabetes and reduced quality of life. HU occurs in approximately 40% of people with type 1 diabetes mellitus (T1DM) and with less frequency in T2DM. Though the aetiology of HU is multifactorial, possible mechanisms include chronic exposure to low blood glucose, antecedent hypoglycaemia, recurrent severe hypoglycaemia and the failure of counter-regulatory hormones. Clinically it manifests as the inability to recognise impeding hypoglycaemia by symptoms, but the mechanisms and mediators remain largely unknown. Prevention and management of HU is complex, and can only be achieved by a multifactorial intervention of clinical care and structured patient education by the diabetes team. Less know regarding the impact of medications on the development or recognition of this condition in patients with diabetes. Several medications are thought to worsen or promote HU, whereas others may have an attenuating effect on the problem. This article reviews recent advances in how the brain senses and responds to hypoglycaemia, novel mechanisms by which people with insulin-treated diabetes develop HU and impaired counter-regulatory responses. The consequences that HU has on the person with diabetes and their family are also described. Finally, it examines the evidence for prevention and treatment of HU, and summarizes the effects of medications that may influence it.

Evidence-informed clinical practice recommendations for treatment of type 1 diabetes complicated by problematic hypoglycemia

Problematic hypoglycemia, defined as two or more episodes per year of severe hypoglycemia or as one episode associated with impaired awareness of hypoglycemia, extreme glycemic lability, or major fear and maladaptive behavior, is a challenge, especially for patients with long-standing type 1 diabetes. Individualized therapy for such patients should include a composite target: optimal glucose control without problematic hypoglycemia. Therefore, we propose a tiered, four-stage algorithm based on evidence of efficacy given the limitations of educational, technological, and transplant interventions. All patients with problematic hypoglycemia should undergo structured or hypoglycemia-specific education programs (stage 1). Glycemic and hypoglycemia treatment targets should be individualized and reassessed every 3-6 months. If targets are not met, one diabetes technology-continuous subcutaneous insulin infusion or continuous glucose monitoring-should be added (stage 2). For patients with continued problematic hypoglycemia despite education (stage 1) and one diabetes technology (stage 2), sensor-augmented insulin pumps preferably with an automated low-glucose suspend feature and/or very frequent contact with a specialized hypoglycemia service can reduce hypoglycemia (stage 3). For patients whose problematic hypoglycemia persists, islet or pancreas transplant should be considered (stage 4). This algorithm provides an evidence-informed approach to resolving problematic hypoglycemia; it should be used as a guide, with individual patient circumstances directing suitability and acceptability to ensure the prudent use of technology and scarce transplant resources. Standardized reporting of hypoglycemia outcomes and inclusion of patients with problematic hypoglycemia in studies of new interventions may help to guide future therapeutic strategies.

Consistency of quantitative scores of hypoglycemia severity and glycemic lability and comparison with continuous glucose monitoring system measures in long-standing type 1 diabetes

BACKGROUND

In long-standing type 1 diabetes (T1D), loss of endogenous insulin secretion and glucose dysregulation can lead to severe hypoglycemia and associated complications. Here, we report the serial consistency and the correlation between different scores that characterize glucose dysregulation using self-monitoring of blood glucose (SMBG), in a cohort of T1D individuals being evaluated for transplant eligibility in Clinical Islet Transplantation Consortium trials.

SUBJECTS AND METHODS

In total, 152 C-peptide-negative T1D subjects with at least one severe hypoglycemia episode in the prior year documented SMBG at enrollment and every 6 months until deemed ineligible or transplanted. SMBG was used to calculate the HYPO score, Lability Index (LI), and mean amplitude of glycemic excursion (MAGE). Additionally, a blinded continuous glucose monitoring system (CGMS) was worn for 72 h at enrollment and every 12 months.

RESULTS

In this cohort, LI was the most consistent (intraclass correlation coefficient=0.70) over time, followed by the HYPO score (0.51), with MAGE being the least consistent (0.36). Although MAGE and LI were highly correlated with each other, neither correlated with CGMS SD or glucose coefficient of variation (CV). Subjects spent a median of 97 min/day at <54 mg/dL using CGMS. The HYPO score correlated with CGMS time below 54 mg/dL and glucose CV.

CONCLUSIONS

The HYPO score and LI are more consistent than MAGE in patients with established T1D experiencing severe hypoglycemic events and may be especially useful both for identifying subjects experiencing the greatest difficulty in maintaining glycemic control and for longitudinal assessment of novel interventions.

The benefits, limitations, and cost-effectiveness of advanced technologies in the management of patients with diabetes mellitus

Hypoglycemia mitigation is critical for appropriately managing patients with diabetes. Advanced technologies are becoming more prevalent in diabetes management, but their benefits have been primarily judged on the basis of hemoglobin A1c. A critical appraisal of the effectiveness and limitations of advanced technologies in reducing both A1c and hypoglycemia rates has not been previously performed. The cost of hypoglycemia was estimated using literature rates of hypoglycemia events resulting in hospitalizations. A literature search was conducted on the effect on A1c and hypoglycemia of advanced technologies. The cost-effectiveness of continuous subcutaneous insulin infusion (CSII) and real-time continuous glucose monitors (RT-CGM) was reviewed. Severe hypoglycemia in insulin-using patients with diabetes costs $4.9-$12.7 billion. CSII reduces A1c in some but not all studies. CSII improves hypoglycemia in patients with high baseline rates. Bolus calculators improve A1c and improve the fear of hypoglycemia but not hypoglycemia rates. RT-CGM alone and when combined with CSII improve A1c with a neutral effect on hypoglycemia rates. Low-glucose threshold suspend systems reduce hypoglycemia with a neutral effect on A1c, and low-glucose predictive suspend systems reduce hypoglycemia with a small increase in plasma glucose levels. In short-term studies, artificial pancreas systems reduce both hypoglycemia rates and plasma glucose levels. CSII and RT-CGM are cost-effective technologies, but their wide adoption is limited by cost, psychosocial, and educational factors. Most currently available technologies improve A1c with a neutral or improved rate of hypoglycemia. Advanced technologies appear to be cost-effective in diabetes management, especially when including the underlying cost of hypoglycemia.

Comparison of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy for glycaemic control in patients with type 1 diabetes: an open-label randomised controlled crossover trial

BACKGROUND

The artificial pancreas is an emerging technology for the treatment of type 1 diabetes and two configurations have been proposed: single-hormone (insulin alone) and dual-hormone (insulin and glucagon). We aimed to delineate the usefulness of glucagon in the artificial pancreas system.

METHODS

We did a randomised crossover trial of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy (continuous subcutaneous insulin infusion) in participants aged 12 years or older with type 1 diabetes. Participants were assigned in a 1:1:1:1:1:1 ratio with blocked randomisation to the three interventions and attended a research facility for three 24-h study visits. During visits when the patient used the single-hormone artificial pancreas, insulin was delivered based on glucose sensor readings and a predictive dosing algorithm. During dual-hormone artificial pancreas visits, glucagon was also delivered during low or falling glucose. During conventional insulin pump therapy visits, patients received continuous subcutaneous insulin infusion. The study was not masked. The primary outcome was the time for which plasma glucose concentrations were in the target range (4·0-10·0 mmol/L for 2 h postprandially and 4·0-8·0 mmol/L otherwise). Hypoglycaemic events were defined as plasma glucose concentration of less than 3·3 mmol/L with symptoms or less than 3·0 mmol/L irrespective of symptoms. Analysis was by modified intention to treat, in which we included data for all patients who completed at least two visits. A p value of less than 0·0167 (0·05/3) was regarded as significant. This trial is registered with ClinicalTrials.gov, number NCT01754337.

FINDINGS

The mean proportion of time spent in the plasma glucose target range over 24 h was 62% (SD 18), 63% (18), and 51% (19) with single-hormone artificial pancreas, dual-hormone artificial pancreas, and conventional insulin pump therapy, respectively. The mean difference in time spent in the target range between single-hormone artificial pancreas and conventional insulin pump therapy was 11% (17; p=0·002) and between dual-hormone artificial pancreas and conventional insulin pump therapy was 12% (21; p=0·00011). There was no difference (15; p=0·75) in the proportion of time spent in the target range between the single-hormone and dual-hormone artificial pancreas systems. There were 52 hypoglycaemic events with conventional insulin pump therapy (12 of which were symptomatic), 13 with the single-hormone artificial pancreas (five of which were symptomatic), and nine with the dual-hormone artificial pancreas (0 of which were symptomatic); the number of nocturnal hypoglycaemic events was 13 (0 symptomatic), 0, and 0, respectively.

INTERPRETATION

Single-hormone and dual-hormone artificial pancreas systems both provided better glycaemic control than did conventional insulin pump therapy. The single-hormone artificial pancreas might be sufficient for hypoglycaemia-free overnight glycaemic control.

FUNDING

Canadian Diabetes Association; Fondation J A De Sève; Juvenile Diabetes Research Foundation; and Medtronic.

Self-reported frequency and impact of hypoglycaemic events in insulin-treated diabetic patients in Austria

Background

Hypoglycaemia is a common side effect of insulin therapy and presents a barrier to diabetes management, however, limited data exist on the real-world frequency of events. We investigated the self-reported rates of non-severe and severe hypoglycaemic events in Austria. We also explored hypoglycaemia awareness, patient–physician communication and the health-related and economic impact of events.

Methods

People with Type-1 or insulin-treated Type-2 diabetes > 15 years of age completed up to 4 questionnaires (weekly intervals). Non-severe hypoglycaemic events were defined by requiring no assistance while severe hypoglycaemic events need help from a third party.

Results

Overall, 553 respondents (40 % Type-1, 60 % Type-2) enrolled, providing a total of 1,773 patient-weeks. The mean annual non-severe event frequencies were 85 for Type-1 and 15–28 for Type-2 (depending on insulin regimen). In respondents who experienced ≥ 1 non-severe event in the study period, annual rates were 18 % higher in Type-1 and 77 % higher in Type-2. The proportion of respondents reporting ‘awareness’ of hypoglycaemic symptoms was 48 % for Type-1 and 43–61 % for Type-2 respondents. The proportion of respondents who rarely/never inform their physician of hypoglycaemic events was 67 % (Type-1) and 43–53 % (Type-2). The most commonly reported health-related impacts were tiredness/fatigue (58 % of events) and reduced alertness (41 % of events).

Conclusion

Non-severe hypoglycaemic events are common in Type-1 and insulin-treated Type-2 diabetes patients in Austria. There may be subgroups of patients who are predisposed to higher rates of non-severe events. Even non-severe events have a negative impact on physical and emotional well-being.

Poorer glycaemic control in type 1 diabetes is associated with reduced self-management and poorer perceived health: a cross-sectional study

AIMS

Many people with type 1 diabetes do not achieve optimal treatment targets despite high patient and professional input. To investigate the reasons underlying suboptimal control we have studied clinical characteristics and self-management behaviours in adults with type 1 diabetes attending a large treatment centre.

METHODS

A questionnaire-based enquiry into self-care behaviours of 380 patients with type 1 diabetes (mean age: 48 (±15) years and mean duration of diabetes: 26 (±15) years), linked with validated measures of impact of treatment on perceived health and hypoglycaemia recognition (Insulin Treatment Satisfaction Questionnaire; and EuroQoL EQ-5D, Gold score) and retrospective case note review of biomedical parameters. The data were analysed using chi-square test, ANOVA, ANCOVA and post-hoc procedures (Tukey's-b) in SPSS-version 18. The minimum significance level was accepted as 0.05.

RESULTS

Sixty three percent of participants used multiple daily injections; 36% continuous subcutaneous insulin infusion. Mean HbA1c was 7.7% (±1.2) [61±-10mmol/mol]; 30% had impaired hypoglycaemia awareness (IHA). Factors significantly related to poor glycaemic control with IHA were longer duration of diabetes (p=0.01); less frequent glucose self-monitoring (p=0.05); and low level of patient-set glucose targets (p<0.001). Patients with IHA and poorer control had significantly lower insulin treatment satisfaction (p<0.001); and perceived health (p<0.001).

CONCLUSIONS

Suboptimal biomedical outcomes in adults with type 1 diabetes attending a specialist intensified insulin therapy clinic are associated with longer duration of diabetes, fewer self-management behaviours and a trend towards poorer perceived health. These data suggest a need for greater emphasis on integration of psychological and self-management support with intensive medical management of type 1 diabetes.

The effect of hypoglycemia on health-related quality of life: Canadian results from a multinational time trade-off survey

OBJECTIVE

The aim of this study was to investigate the impact of hypoglycemia according to severity and time of onset on health-related quality of life (HRQoL) in a Canadian population.

METHODS

Time trade-off (TTO) methodology was used to estimate health utilities associated with hypoglycemic events in a representative sample of the Canadian population. A global analysis conducted in the United Kingdom, Canada, Germany and Sweden has been published. The present Canadian analysis focuses on 3 populations: general, type 1 and type 2 diabetes. Using a web-based survey, participants (>18 years) assessed the utility of 13 different health states (severe, non-severe, daytime and nocturnal hypoglycemia at different frequencies) using a scale from 1 (perfect health) to 0 (death). The average disutility value for each type of event was calculated.

RESULTS

Of 2258 participants, 1696 completers were included in the analysis. A non-severe nocturnal hypoglycemic event was associated with a significantly greater disutility than a non-severe daytime event (-0.0076 vs. -0.0056, respectively; p=0.05), while there was no statistically significant difference between severe nocturnal and severe daytime events (-0.0616 vs. -0.0592; p=0.76). Severe hypoglycemia was associated with greater disutility than non-severe hypoglycemia (p<0.0001). Similar trends were reported in participants with diabetes.

CONCLUSIONS

The findings presented here show that any form of hypoglycemia had a negative impact on HRQoL in a Canadian population. Nocturnal and/or severe hypoglycemia had a greater negative impact on HRQoL compared with daytime and/or non-severe events. This highlights the importance of preventing the development and nocturnal manifestation of hypoglycemia in patients with diabetes.

Cognitive, behavioural and psychological barriers to the prevention of severe hypoglycaemia: A qualitative study of adults with type 1 diabetes

OBJECTIVES

Severe hypoglycaemia affects approximately one in three people with type 1 diabetes and is the most serious side effect of insulin therapy. Our aim was to explore individualistic drivers of severe hypoglycaemia events.

METHODS

In-depth semi-structured interviews were conducted with a purposive sample of 17 adults with type 1 diabetes and a history of recurrent severe hypoglycaemia, to elicit experiences of hypoglycaemia (symptoms/awareness, progression from mild to severe and strategies for prevention/treatment). Interviews were analysed using an adapted grounded theory approach.

RESULTS

Three main themes emerged: hypoglycaemia-induced cognitive impairment, behavioural factors and psychological factors. Despite experiencing early hypoglycaemic symptoms, individuals often delayed intervention due to impaired/distracted attention, inaccurate risk assessment, embarrassment, worry about rebound hyperglycaemia or unavailability of preferred glucose source. Delay coupled with use of a slow-acting glucose source compromised prevention of severe hypoglycaemia.

CONCLUSION

Our qualitative data highlight the multifaceted, idiosyncratic nature of severe hypoglycaemia and confirm that individuals with a history of recurrent severe hypoglycaemia may have specific thought and behaviour risk profiles. Individualised prevention plans are required, emphasising both the need to attend actively to mild hypoglycaemic symptoms and to intervene promptly with an appropriate, patient-preferred glucose source to prevent progression to severe hypoglycaemia.

Real-time continuous glucose monitoring significantly reduces severe hypoglycemia in hypoglycemia-unaware patients with type 1 diabetes

OBJECTIVE

To evaluate the effect of continuous glucose monitoring (CGM) on the frequency of severe hypoglycemia (SH) in patients with established hypoglycemia unawareness.

RESEARCH DESIGN AND METHODS

We conducted a retrospective audit of 35 patients with type 1 diabetes and problematic hypoglycemia unawareness, despite optimized medical therapy (continuous subcutaneous insulin infusion/multiple daily insulin injections), who used CGM for >1 year.

RESULTS

Over a 1-year follow-up period, the median rates of SH were reduced from 4.0 (interquartile range [IQR] 0.75-7.25) episodes/patient-year to 0.0 (0.0-1.25) episodes/patient-year (P < 0.001), and the mean (±SD) rates were reduced from 8.1 ± 13 to 0.6 ± 1.2 episodes/year (P = 0.005). HbA1c was reduced from 8.1 ± 1.2% to 7.6 ± 1.0% over the year (P = 0.005). The mean Gold score, measured in 19 patients, did not change: 5.1 ± 1.5 vs. 5.2 ± 1.9 (P = 0.67).

CONCLUSIONS

In a specialist experienced insulin pump center, in carefully selected patients, CGM reduced SH while improving HbA1c but failed to restore hypoglycemia awareness.

Meta-analysis of insulin aspart versus regular human insulin used in a basal-bolus regimen for the treatment of diabetes mellitus

BACKGROUND

The objective of the current study was to compare the efficacy of two different insulin formulations, insulin aspart (IAsp) and regular human insulin (RHI), for prandial insulin coverage with neutral protamine Hagedorn (NPH) insulin as basal insulin using a meta-analysis approach. The primary endpoint was change in A1c over time. Secondary endpoints included incidence of hypoglycemia and postprandial glycemic control.

METHODS

Clinical trials (Type 1 and Type 2 diabetes) complying with Good Clinical Practice, and with individual patient data, were included in the meta-analysis. Trials were randomized, consisting of (at least) two treatment arms and had a minimum duration of 12 weeks. Estimates were calculated using fixed-effects and random-effects models. Heterogeneity was assessed for each analysis. The effect of baseline parameters on A1c was analyzed in extended simultaneous models.

RESULTS

The mean difference in A1c was 0.1% (95% confidence interval [CI] [-0.15; -0.04], P < 0.001) in favor of IAsp. Higher accumulated dose of IAsp, higher age and increased rates of hypoglycemia were associated with improved A1c outcome. Fasting plasma glucose was not significantly different between regimens. Postprandial glucose was significantly lower after treatment with IAsp compared with RHI, but the analysis did present a significant level of heterogeneity (P < 0.001). The overall rate of hypoglycemia was the same with both regimens, but nocturnal hypoglycemia was significantly lower with IAsp.

CONCLUSIONS

A basal-bolus regimen with IAsp as bolus insulin provided minimal, but statistically significant, improvement in overall glycemic control with a lower rate of nocturnal hypoglycemic episodes, compared with a corresponding regimen with bolus RHI.

Clinical implications and economic impact of accuracy differences among commercially available blood glucose monitoring systems

BACKGROUND

Despite accuracy standards, there are performance differences among commercially available blood glucose monitoring (BGM) systems. The objective of this analysis was to assess the potential clinical and economic impact of accuracy differences of various BGM systems using a modeling approach.

METHODS

We simulated additional risk of hypoglycemia due to blood glucose (BG) measurement errors of five different BGM systems based on results of a real-world accuracy study, while retaining other sources of glycemic variability. Using data from published literature, we estimated an annual additional number of required medical interventions as a result of hypoglycemia. We based our calculations on patients with type 1 diabetes mellitus (T1DM) and T2DM requiring multiple daily injections (MDIs) of insulin in a U.S. health care system. We estimated additional costs attributable to treatment of severe hypoglycemic episodes resulting from BG measurement errors.

RESULTS

Results from our model predict an annual difference of approximately 296,000 severe hypoglycemic episodes from BG measurement errors for T1DM (105,000 for T2DM MDI) patients for the estimated U.S. population of 958,800 T1DM and 1,353,600 T2DM MDI patients, using the least accurate BGM system versus patients using the most accurate system in a U.S. health care system. This resulted in additional direct costs of approximately $339 million for T1DM and approximately $121 million for T2DM MDI patients per year.

CONCLUSION

Our analysis shows that error patterns over the operating range of BGM meter may lead to relevant clinical and economic outcome differences that may not be reflected in a common accuracy metric or standard. Further research is necessary to validate the findings of this model-based approach.