Changes in attitudes to awareness of hypoglycaemia during a hypoglycaemia awareness restoration programme are associated with avoidance of further severe hypoglycaemia episodes within 24 months: the A2A in HypoCOMPaSS study

AIMS/HYPOTHESIS

The aims of this study were to assess cognitions relating to hypoglycaemia in adults with type 1 diabetes and impaired awareness of hypoglycaemia before and after the multimodal HypoCOMPaSS intervention, and to determine cognitive predictors of incomplete response (one or more severe hypoglycaemic episodes over 24 months).

METHODS

This analysis included 91 adults with type 1 diabetes and impaired awareness of hypoglycaemia who completed the Attitudes to Awareness of Hypoglycaemia (A2A) questionnaire before, 24 weeks and 24 months after the intervention, which comprised a short psycho-educational programme with optimisation of insulin therapy and glucose monitoring.

RESULTS

The age and diabetes duration of the participants were 48±12 and 29±12 years, respectively (mean±SD). At baseline, 91% reported one or more severe hypoglycaemic episodes over the preceding 12 months; this decreased to <20% at 24 weeks and after 24 months (p=0.001). The attitudinal barrier 'hyperglycaemia avoidance prioritised' (η²_p=0.250, p=0.001) decreased from baseline to 24 weeks, and this decrease was maintained at 24 months (mean±SD=5.3±0.3 vs 4.3±0.3 vs 4.0±0.3). The decrease in 'asymptomatic hypoglycaemia normalised' from baseline (η²_p=0.113, p=0.045) was significant at 24 weeks (1.5±0.3 vs 0.8±0.2). Predictors of incomplete hypoglycaemia response (one or more further episodes of severe hypoglycaemia) were higher baseline rates of severe hypoglycaemia, higher baseline scores for 'asymptomatic hypoglycaemia normalised', reduced change in 'asymptomatic hypoglycaemia normalised' scores at 24 weeks, and lower baseline 'hypoglycaemia concern minimised' scores (all p<0.05).

CONCLUSIONS/INTERPRETATION

Participation in the HypoCOMPaSS RCT was associated with improvements in hypoglycaemia-associated cognitions, with 'hyperglycaemia avoidance prioritised' most prevalent. Incomplete prevention of subsequent severe hypoglycaemia episodes was associated with persistence of the cognition 'asymptomatic hypoglycaemia normalised'. Understanding and addressing cognitive barriers to hypoglycaemia avoidance is important in individuals prone to severe hypoglycaemia episodes.

CLINICAL TRIALS REGISTRATION

www.isrctn.org : ISRCTN52164803 and https://eudract.ema.europa.eu : EudraCT2009-015396-27.

Association between hypoglycaemic glucose variability and autonomic function in type1 diabetes with impaired hypoglycaemia awareness

Cardiovascular autonomic neuropathy (CAN) is suggested to underlie hypoglycaemic risk in impaired awareness of hypoglycaemia (IAH). We assessed the prevalence of CAN and the association between glucose variability (GV) and cardiovascular autonomic function in patients with type 1 diabetes (T1DM) and IAH. This study is a post-hoc-analysis of results obtained with the IN-CONTROL-trial, designed to assess the effects of continuous glucose monitoring (CGM) on glycaemia. Forty participants (aged 46.4 ± 11.4 years, diabetes duration 29.1 ± 13.5 years, HbA1c 7.5 ± 0.8%(58.2 ± 8.8 mmol/mol)) underwent 2-week blinded CGM measurements to obtain GV indices. Standardized cardiovascular reflex tests were used to determine the presence of CAN. Cardiovascular autonomic function was assessed with heart rate variability (HRV) measures. 14(35%) participants were classified as having CAN. Participants with CAN had lower percentage time spent in hypoglycaemic range and low blood glucose index(LBGI). After correction for confounders, a significant positive association was found between the coefficient of variation (CV) or time spent in hypoglycaemic range and HRV measures SDRR or RMSSD, and between LBGI and RMSSD. In patients with T1DM and IAH, hypoglycaemic parameters were associated with better cardiovascular autonomic function and lower prevalence of CAN. This suggests that autonomic neuropathy does not seem to further deteriorate hypoglycaemic risk in patients with IAH.

Characteristics of adults with type 1 diabetes and treatment-resistant problematic hypoglycaemia: a baseline analysis from the HARPdoc RCT

AIMS/HYPOTHESIS

Problematic hypoglycaemia still complicates insulin therapy for some with type 1 diabetes. This study describes baseline emotional, cognitive and behavioural characteristics in participants in the HARPdoc trial, which evaluates a novel intervention for treatment-resistant problematic hypoglycaemia.

METHODS

We documented a cross-sectional baseline description of 99 adults with type 1 diabetes and problematic hypoglycaemia despite structured education in flexible insulin therapy. The following measures were included: Hypoglycaemia Fear Survey II (HFS-II); Attitudes to Awareness of Hypoglycaemia questionnaire (A2A); Hospital Anxiety and Depression Index; and Problem Areas In Diabetes. k-mean cluster analysis was applied to HFS-II and A2A factors. Data were compared with a peer group without problematic hypoglycaemia, propensity-matched for age, sex and diabetes duration (n = 81).

RESULTS

The HARPdoc cohort had long-duration diabetes (mean ± SD 35.8 ± 15.4 years), mean ± SD Gold score 5.3 ± 1.2 and a median (IQR) of 5.0 (2.0-12.0) severe hypoglycaemia episodes in the previous year. Most individuals had been offered technology and 49.5% screened positive for anxiety (35.0% for depression and 31.3% for high diabetes distress). The cohort segregated into two clusters: in one (n = 68), people endorsed A2A cognitive barriers to hypoglycaemia avoidance, with low fear on HFS-II factors; in the other (n = 29), A2A factor scores were low and HFS-II high. Anxiety and depression scores were significantly lower in the comparator group.

CONCLUSIONS/INTERPRETATION

The HARPdoc protocol successfully recruited people with treatment-resistant problematic hypoglycaemia. The participants had high anxiety and depression. Most of the cohort endorsed unhelpful health beliefs around hypoglycaemia, with low fear of hypoglycaemia, a combination that may contribute to persistence of problematic hypoglycaemia and may be a target for adjunctive psychological therapies.

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.

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.

Pumps that predict and manage low blood glucose are superior to pumps with stand-alone CGM for reducing hypoglycaemia in type 1 diabetes patients in a real-world setting

BACKGROUND

This study aimed to assess the efficacy of insulin pumps with automated predictive low-glucose insulin suspension in a real-world setting compared with stand-alone flash glucose monitoring (FGM).

METHODS

The data analyzed were uploaded by patients with type 1 diabetes (n=195) treated with external insulin pumps [either a MiniMed 640G system (Medtronic) including SmartGuard technology that predicts and manages low glucose (n=61) or an Omnipod patch pump accompanied by a FreeStyle Libre sensor (Abbott) for FGM (n=134)].

RESULT

The median (25th-75th percentile) time spent with sensor glucose values≤3.9mmol/L was 0.9% (0.4-1.55) vs. 5.6% (3.05-9.55) in the predictive low-glucose suspend group vs. FGM users, respectively (P<0.0001), with similar results obtained for median time spent with sensor glucose values≤3mmol/L (P<0.0001). The group using sensor-integrated pumps had lower % coefficient of variation (CV) values and lower mean amplitude glycaemic excursions (P<0.0001). Mean glucose values as well as measured HbA_1c levels were also lower.

CONCLUSION

These real-world data show that predictive low-glucose insulin suspension is more effective than pumps with stand-alone FGM for reducing hypoglycaemic events, and could be of benefit to patients at risk of hypoglycaemia as well as those lacking in hypoglycaemic awareness.

The impact of hypoglycaemia awareness status on regional brain responses to acute hypoglycaemia in men with type 1 diabetes

AIMS/HYPOTHESIS

Impaired awareness of hypoglycaemia (IAH) in type 1 diabetes increases the risk of severe hypoglycaemia sixfold and can be resistant to intervention. We explored the impact of IAH on central responses to hypoglycaemia to investigate the mechanisms underlying barriers to therapeutic intervention.

METHODS

We conducted [¹⁵O]water positron emission tomography studies of regional brain perfusion during euglycaemia (target 5 mmol/l), hypoglycaemia (achieved level, 2.4 mmol/l) and recovery (target 5 mmol/l) in 17 men with type 1 diabetes: eight with IAH, and nine with intact hypoglycaemia awareness (HA).

RESULTS

Hypoglycaemia with HA was associated with increased activation in brain regions including the thalamus, insula, globus pallidus (GP), anterior cingulate cortex (ACC), orbital cortex, dorsolateral frontal (DLF) cortex, angular gyrus and amygdala; deactivation occurred in the temporal and parahippocampal regions. IAH was associated with reduced catecholamine and symptom responses to hypoglycaemia vs HA (incremental AUC: autonomic scores, 26.2 ± 35.5 vs 422.7 ± 237.1; neuroglycopenic scores, 34.8 ± 88.8 vs 478.9 ± 311.1; both p < 0.002). There were subtle differences (p < 0.005, k ≥ 50 voxels) in brain activation at hypoglycaemia, including early differences in the right central operculum, bilateral medial orbital (MO) cortex, and left posterior DLF cortex, with additional differences in the ACC, right GP and post- and pre-central gyri in established hypoglycaemia, and lack of deactivation in temporal regions in established hypoglycaemia.

CONCLUSIONS/INTERPRETATION

Differences in activation in the post- and pre-central gyri may be expected in people with reduced subjective responses to hypoglycaemia. Alterations in the activity of regions involved in the drive to eat (operculum), emotional salience (MO cortex), aversion (GP) and recall (temporal) suggest differences in the perceived importance and urgency of responses to hypoglycaemia in IAH compared with HA, which may be key to the persistence of the condition.

Impaired hypoglycaemia awareness in type 1 diabetes: lessons from the lab

Hypoglycaemia remains the most common metabolic adverse effect of insulin and sulfonylurea therapy in diabetes. Repeated exposure to hypoglycaemia leads to a change in the symptom complex that characterises hypoglycaemia, culminating in a clinical phenomenon referred to as impaired awareness of hypoglycaemia (IAH). IAH effects approximately 20-25% of people with type 1 diabetes and increases the risk of severe hypoglycaemia. This review focuses on the mechanisms that are responsible for the much higher frequency of hypoglycaemia in people with diabetes compared with those without, and subsequently how repeated exposure to hypoglycaemia leads to the development of IAH. The mechanisms that result in IAH development are incompletely understood and likely to reflect changes in multiple aspects of the counterregulatory response to hypoglycaemia, from adaptations within glucose and non-glucose-sensing cells to changes in the integrative networks that govern glucose homeostasis. Finally, we propose that the general process that incorporates many of these changes and results in IAH following recurrent hypoglycaemia is a form of adaptive memory called 'habituation'.

Recent Updates on Type 1 Diabetes Mellitus Management for Clinicians

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune condition that requires life-long administration of insulin. Optimal management of T1DM entails a good knowledge and understanding of this condition both by the physician and the patient. Recent introduction of novel insulin preparations, technological advances in insulin delivery and glucose monitoring, such as continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring and improved understanding of the detrimental effects of hypoglycaemia and hyperglycaemia offer new opportunities and perspectives in T1DM management. Evidence from clinical trials suggests an important role of structured patient education. Our efforts should be aimed at improved metabolic control with concomitant reduction of hypoglycaemia. Despite recent advances, these goals are not easy to achieve and can put significant pressure on people with T1DM. The approach of physicians should therefore be maximally supportive. In this review, we provide an overview of the recent advances in T1DM management focusing on novel insulin preparations, ways of insulin administration and glucose monitoring and the role of metformin or sodium-glucose co-transporter 2 inhibitors in T1DM management. We then discuss our current understanding of the effects of hypoglycaemia on human body and strategies aimed at mitigating the risks associated with hypoglycaemia.

Cognitive deficits associated with impaired awareness of hypoglycaemia in type 1 diabetes

AIMS/HYPOTHESIS

The aim of this study was to compare cognitive function in adults with type 1 diabetes who have impaired awareness of hypoglycaemia with those who have normal awareness of hypoglycaemia. A putative association was sought between cognitive test scores and a history of severe hypoglycaemia.

METHODS

A total of 68 adults with type 1 diabetes were included: 33 had impaired and 35 had normal awareness of hypoglycaemia, as confirmed by formal testing. The groups were matched for age, sex and diabetes duration. Cognitive tests of verbal memory, object-location memory, pattern separation, executive function, working memory and processing speed were administered.

RESULTS

Participants with impaired awareness of hypoglycaemia scored significantly lower on the verbal and object-location memory tests and on the pattern separation test (Cohen's d -0.86 to -0.55 [95% CI -1.39, -0.05]). Participants with impaired awareness of hypoglycaemia had reduced planning ability task scores, although the difference was not statistically significant (Cohen's d 0.57 [95% CI 0, 1.14]). Frequency of exposure to severe hypoglycaemia correlated with the number of cognitive tests that had not been performed according to instructions.

CONCLUSIONS/INTERPRETATION

Impaired awareness of hypoglycaemia was associated with diminished learning, memory and pattern separation. These cognitive tasks all depend on the hippocampus, which is vulnerable to neuroglycopenia. The findings suggest that hypoglycaemia contributes to the observed correlation between impaired awareness of hypoglycaemia and impaired cognition.

Severe hypoglycaemia and its association with psychological well-being in Australian adults with type 1 diabetes attending specialist tertiary clinics

AIM

To investigate severe hypoglycaemia (SH) in adults with type 1 diabetes and its associations with impaired awareness of hypoglycaemia (IAH), clinical, psychological and socio-demographic factors.

METHODS

Attendees of three specialist diabetes clinics in Melbourne, Australia completed questions about frequency of SH in the past six months; impaired awareness of hypoglycaemia (Gold score); and measures of general emotional well-being (WHO-5), diabetes-specific positive well-being (subscale of W-BQ28), diabetes-related distress (PAID) and fear of hypoglycaemia (HFS).

RESULTS

Of 422 participants (mean ± SD age 37.5 ± 15.0 years; 54% women), 78 (18.5%) reported at least one SH event and 86 (20.5%) had IAH. SH and IAH frequencies were similar at all clinics. In total, 194 SH events were reported, with 10 people experiencing 40% of events. Compared with those without SH, participants with SH had longer diabetes duration, were younger at diabetes onset and more likely to have IAH (p<0.01). Those with SH had greater fear of hypoglycaemia and diabetes-related distress, poorer general emotional well-being, and lower diabetes-specific positive well-being, (p<0.01). There were no associations with age, gender, insulin regimen or HbA1c.

CONCLUSIONS

This study has identified that SH and IAH in Australian adults with type 1 diabetes exist at similar levels to those reported in US and European research. SH was significantly associated with IAH and fear of hypoglycaemia. Assessment of hypoglycaemia, IAH and psychological well-being as part of a routine diabetes clinic visit was well accepted by attendees and enabled identification of those who may benefit from medical, educational or therapeutic interventions.