Preventing severe hypoglycemia in adults with type 2 diabetes (PHT2): Design, delivery and evaluation framework for a randomized controlled trial

BACKGROUND

Severe hypoglycemia is a common and feared complication of medications used to lower blood glucose levels in individuals with diabetes. Psychoeducational interventions can prevent severe hypoglycemia in individuals with type 1 diabetes (T1D). We aim to determine the effectiveness of this approach among adults with type 2 diabetes (T2D) at elevated risk for severe hypoglycemia.

METHODS

Preventing Hypoglycemia in Type 2 diabetes (PHT2) is a two-arm, parallel, randomized controlled trial. Participants are eligible if they are adults with T2D receiving care at an integrated group practice in Washington state and have experienced one or more episodes of severe hypoglycemia in the prior 12 months or have impaired awareness of hypoglycemia (Gold score ≥ 4). Participants are randomized to proactive nurse care management with or without my hypo compass, an evidence-based, psychoeducational intervention combining group and individual self-management training. For this study, my hypo compass was adapted to be suitable for adults with T2D and from an in-person to a virtual intervention over videoconference and telephone. The primary outcome is any self-reported severe hypoglycemia in the 12 months following the start of the intervention. Secondary outcomes include biochemical measures of hypoglycemia, self-reported hypoglycemia awareness, fear of hypoglycemia, and emergency department visits and hospitalizations for severe hypoglycemia. The study includes a process evaluation to assess implementation fidelity and clarify the causal pathway.

CONCLUSION

The PHT2 trial will compare the effectiveness of two approaches for reducing severe hypoglycemia in adults with T2D.

TRIAL REGISTRATION

clinicaltrials.gov, # NCT04863872.

Identification of factors associated with fear of hypoglycemia using the capability, opportunity, motivation and behavior model in people with type 2 diabetes mellitus: a cross-sectional study

AIMS

To examined the relationship between fear of hypoglycemia and certain variables in people with type 2 diabetes mellitus (T2DM) based on the Capability, Opportunity, Motivation, and Behavior model, combined with the context unique to people with diabetes to provide a basis for developing targeted nursing interventions.

METHODS

In this cross-sectional study, 212 people with T2DM were recruited from February 2021 to July 2021. Data were collected using the Hypoglycaemia Fear Survey, Gold score, Patient Assessment of Chronic Illness Care (PACIC) scale and Diabetic Self-Management Attitudes Scale. Multiple linear regression analysis was performed to determine the predictors of fear of hypoglycemia using SPSS 26.0.

RESULTS

The mean fear of hypoglycemia score was 74.88 ± 18.28 (range: 37.00-132.00). In people with T2DM, the frequency of blood glucose monitoring, the frequency of hypoglycemia in the past half-year, degree of understanding of hypoglycemia, impaired awareness of hypoglycemia, PACIC, and self-management attitude of diabetes were the influencing factors of fear of hypoglycemia (adjusted R2 = 0.560, F[21,190] = 13.800, P < 0.001). These variables explained 56.0% of the variance in the fear of hypoglycemia.

CONCLUSIONS

The level of fear of hypoglycemia in people with T2DM was relatively high. In addition to paying attention to the disease characteristics of people with T2DM, medical staff should also pay attention to patients' own perception and handling ability of disease and hypoglycemia, attitude toward self-management behavior and external environment support, all of which have a positive effect on improving the fear of hypoglycemia in people with T2DM, optimizing the self-management level and improving quality of life.

Prevalence and contributing factors of impaired awareness of hypoglycemia in patients with type 2 diabetes: a meta-analysis

AIMS

To conduct a systematic review to summarize the definition, measurement tools, prevalence, and contributing factors of impaired awareness of hypoglycemia (IAH) in type 2 diabetes mellitus (T2DM).

METHODS

A reproducible search strategy was used to identify factors affecting IAH in T2DM in PubMed, MEDLINE, EMBASE, Cochrane, PsycINFO, and CINAHL from inception until 2022. Literature screening, quality evaluation, and information extraction were performed independently by 2 investigators. A meta-analysis of prevalence was performed using Stata 17.0.

RESULTS

The pooled prevalence of IAH in patients with T2DM was 22% (95%CI:14-29%). Measurement tools included the Gold score, Clarke's questionnaire, and the Pedersen-Bjergaard scale. IAH in T2DM was associated with sociodemographic factors (age, BMI, ethnicity, marital status, education level, and type of pharmacy patients visited), clinical disease factors (disease duration, HbAlc, complications, insulin therapy regimen, sulfonylureas use, and the frequency and severity of hypoglycemia), and behavior and lifestyle (smoking and medication adherence).

CONCLUSION

The study found a high prevalence of IAH in T2DM, with an increased risk of severe hypoglycemia, suggesting that medical workers should take targeted measures to address sociodemographic factors, clinical disease, and behavior and lifestyle to reduce IAH in T2DM and thus reduce hypoglycemia in patients.

Automated Insulin Delivery for Hypoglycemia Avoidance and Glucose Counterregulation in Long-Standing Type 1 Diabetes with Hypoglycemia Unawareness

Objective: Automated insulin delivery (AID) may benefit individuals with long-standing type 1 diabetes where frequent exposure to hypoglycemia impairs counterregulatory responses. This study assessed the effect of 18 months AID on hypoglycemia avoidance and glucose counterregulatory responses to insulin-induced hypoglycemia in long-standing type 1 diabetes complicated by impaired awareness of hypoglycemia. Methods: Ten participants mean ± standard deviation age 49 ± 16 and diabetes duration 34 ± 16 years were initiated on AID. Continuous glucose monitoring was paired with actigraphy to assess awake- and sleep-associated hypoglycemia exposure every 3 months. Hyperinsulinemic hypoglycemic clamp experiments were performed at baseline, 6, and 18 months postintervention. Hypoglycemia exposure was reduced by 3 months, especially during sleep, with effects sustained through 18 months (P ≤ 0.001) together with reduced glucose variability (P < 0.01). Results: Hypoglycemia awareness and severity scores improved (P < 0.01) with severe hypoglycemia events reduced from median (interquartile range) 3 (3-10) at baseline to 0 (0-1) events/person·year postintervention (P = 0.005). During the hypoglycemic clamp experiments, no change was seen in the endogenous glucose production (EGP) response, however, peripheral glucose utilization during hypoglycemia was reduced following intervention [pre: 4.6 ± 0.4, 6 months: 3.8 ± 0.5, 18 months: 3.4 ± 0.3 mg/(kg·min), P < 0.05]. There were increases over time in pancreatic polypeptide (Pre:62 ± 29, 6 months:127 ± 44, 18 months:176 ± 58 pmol/L, P < 0.01), epinephrine (Pre: 199 ± 53, 6 months: 332 ± 91, 18 months: 386 ± 95 pg/mL, P = 0.001), and autonomic symptom (Pre: 6 ± 2, 6 months: 6 ± 2, 18 months: 10 ± 2, P < 0.05) responses. Conclusions: AID led to a sustained reduction of hypoglycemia exposure. EGP in response to insulin-induced hypoglycemia remained defective, however, partial recovery of glucose counterregulation was evidenced by a reduction in peripheral glucose utilization likely mediated by increased epinephrine secretion and, together with improved autonomic symptoms, may contribute to the observed clinical reduction in hypoglycemia.

Common Sense Model program on illness perceptions in patients with impaired awareness of hypoglycemia

BACKGROUND

Illness perceptions are important for patients with insulin-treated type 2 diabetes mellitus (T2DM) and impaired awareness of hypoglycemia (IAH), as they determine health-related behaviors and motivations. Patients with IAH in many countries have poor illness perception, and there is a paucity of research exploring the effectiveness of Common Sense Model (CSM)-based interventions in this population.

OBJECTIVE

To investigate the effects of a CSM-based intervention program on perceptions of illness in patients with insulin-treated T2DM and IAH.

DESIGN

Quasi-randomized controlled trialMethods: 78 patients with IAH receiving routine care were included. The intervention group (n = 39) participated in a CSM-based program, whereas the control group (n = 39) did not. Illness perceptions, coping styles, hypoglycemia fear, and awareness of hypoglycemia at baseline, 1 month, and 3 months were analyzed and compared between the two groups.

RESULTS

The intervention group exhibited significant improvements in consequences (β = -1.615, P = 0.032); personal control (β = -1.897, P = 0.006); treatment control (β = -1.274, P = 0.046); and positive coping style (β = 4.872, P = 0.002) at the 3-month follow-up, and timeline (β = 2.769, P = 0.004) at the 1-month follow-up. Hypoglycemia fear and awareness were not significantly improved in the intervention group compared with the control group. No intervention-related adverse events were observed.

CONCLUSIONS

A CSM-based intervention program can modify illness perceptions to an extent and improve the positive coping style in patients with IAH.Impact statement: Nurses should conduct a CSM-based intervention program to help patients with IAH improve illness perceptions.

Hypoglycemia symptoms are reduced in hospitalized patients with diabetes

AIMS

Hospitalized patients with diabetes are have an impaired ability to detect hypoglycemia events. The purpose of this study was to compare hypoglycemia symptom scores (HSS) in hospitalized patients with diabetes after a documented blood glucose (BG) <70mg/dl with recalled HSS with outpatient hypoglycemia events.

METHODS

Non-critically ill hospitalized patients with diabetes grouped as symptomatic (n=23) or asymptomatic (n=32) at time of index hypoglycemia completed a standardized HSS-Questionnaires (HSS-Q) related to the inpatient event and to recall of symptoms with outpatient hypoglycemia.

RESULTS

After controlling for BG at time of index hypoglycemia (49.8±11.4 vs. 57.4±6.8mg/dl, p=0.02), symptomatic patients reported higher HSS than asymptomatic patients with the inpatient event (11.6±7.3 vs. 1.5±3.4, p<0.001) and in the outpatient setting (13.9±8.6 vs. 10.1±10.6, p<0.01). Recurrent hypoglycemia was more frequent in asymptomatic patients (13% vs. 44%, p=0.015) during the hospitalization.

CONCLUSIONS

Compared to symptomatic patients, asymptomatic patients had lower inpatient and outpatient HSS and more frequent recurrent hypoglycemia events. These results suggest modification of glycemic management strategies in high risk patients to reduce risk for hypoglycemia events.

Associations Between the Time in Hypoglycemia and Hypoglycemia Awareness Status in Type 1 Diabetes Patients Using Continuous Glucose Monitoring Systems

Background: Continuous glucose monitoring (CGM) systems help reduce hypoglycemia in patients with type 1 diabetes (T1D). It remains unclear whether T1D patients with impaired awareness of hypoglycemia (IAH) continue to develop more hypoglycemia than those with normal hypoglycemia awareness (NA) despite CGM use. Materials and Methods: For this cross-sectional observational study, 99 T1D patients using real-time CGMs for ≥86% of time were recruited. Fifty and 49 patients were found to have NA and IAH (based on the Clarke questionnaire), respectively. Two-week CGM hypoglycemia data were collected. Results: IAH was associated with greater percentages of CGM values <70 and <54 mg/dL (P = 0.012, P = 0.004) compared to NA. Clarke scores correlated positively with the percentage of CGM values <70 and <54 mg/dL (P = 0.013, P = 0.004). IAH was also related to more events with glucose <70 and <54 mg/dL determined either with at ≥1 time point (P = 0.048, P = 0.003) or lasting ≥20 min (P = 0.016, P = 0.004). IAH patients presented with more day-time events with glucose <54 mg/dL (P = 0.015), nocturnal events with glucose levels <70 and <54 mg/dL (P = 0.009, P = 0.007) and longer day-time event duration with glucose levels <70 and <54 mg/dL (P < 0.001, P = 0.006), respectively. Conclusions: T1D patients with IAH continue to experience more hypoglycemia despite dedicated CGM use.

Hypoglycemia unawareness and autonomic dysfunction in diabetes: Lessons learned and roles of diabetes technologies

Impaired awareness of hypoglycemia (IAH) is a reduction in the ability to recognize low blood glucose levels that would otherwise prompt an appropriate corrective therapy. Identified in approximately 25% of patients with type 1 diabetes, IAH has complex pathophysiology, and might lead to serious and potentially lethal consequences in patients with diabetes, particularly in those with more advanced disease and comorbidities. Continuous glucose monitoring systems can provide real-time glucose information and generate timely alerts on rapidly falling or low blood glucose levels. Given their improvements in accuracy, affordability and integration with insulin pump technology, continuous glucose monitoring systems are emerging as critical tools to help prevent serious hypoglycemia and mitigate its consequences in patients with diabetes. This review discusses the current knowledge on IAH and effective diagnostic methods, the relationship between hypoglycemia and cardiovascular autonomic neuropathy, a practical approach to evaluating cardiovascular autonomic neuropathy for clinicians, and recent evidence from clinical trials assessing the effects of the use of CGM technologies in patients with type 1 diabetes with IAH.

Real life evidence that impaired awareness of hypoglycemia persists for years in patients with type 1 diabetes

AIMS

To determine if impaired awareness of hypoglycemia in patients with type 1 diabetes persists over time and to assess if continuous glucose monitoring use was associated with improved awareness of hypoglycemia in our population.

METHODS

Thirty-six with type 1 diabetes and impaired awareness of hypoglycemia who participated in studies on impaired awareness of hypoglycemia between 2009 and 2015 were contacted to complete an online survey. The survey included the Cox/Clarke and Gold hypoglycemia questionnaires and questions about continuous glucose monitoring use.

RESULTS

23 of 36 (63%) subjects contacted completed the survey. (12 M, 11 F; median age 51 years, median diabetes duration 34 years). One had had an islet cell transplant and was excluded. Persistent impaired awareness of hypoglycemia was found in 19/22 (86%) using the Cox questionnaire and 18/22 (82%) using the Gold questionnaire. Consistent use of continuous glucose monitoring over the last six months defined as using a device ≥75% of time over the last 6 months was reported by 67% (12/18) and 68% (13/19) of participants with persistent impaired awareness of hypoglycemia as measured by Gold and Cox; respectively. Nineteen of the 22 participants (86%) reported severe hypoglycemia over the last six months.

CONCLUSION

Impaired awareness of hypoglycemia persisted in >80% of the subjects with type 1 diabetes we studied between 2009 and 2015. While the consistent use of continuous glucose monitoring among our participants was high; it did not translate into restoration of hypoglycemia awareness in this population. This real world data shows that severe hypoglycemia continues to be a frequent problem in this patient population.

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.

Continuous Glucose Monitoring in Patients with Type 1 Diabetes and Impaired Awareness of Hypoglycemia: Also Effective in Patients with Psychological Distress?

The aim of this study was to evaluate whether psychological distress modifies the effect of continuous glucose monitoring (CGM) in patients with type 1 diabetes (T1D) and impaired awareness of hypoglycemia. Fifty-two patients with T1D and impaired awareness of hypoglycemia participated in an earlier reported randomized crossover trial with two 16-week intervention periods comparing CGM with self-monitoring of blood glucose (SMBG). During the CGM phase, time spent in euglycemia (4-10 mmol/L), the primary outcome, was 9.6% higher compared with the SMBG phase (P < 0.0001). Psychological distress was operationalized as low emotional well-being (World Health Organization Well-being Index 5 [WHO-5] < 50), high diabetes-related distress (Problem Areas in Diabetes 5 [PAID-5] ≥ 8), and/or high fear of hypoglycemia (Hypoglycemia Fear Survey [HFS] Worry > mean HFS Worry score +1 standard deviation). Modifying effects were assessed by analyzing psychological distress score × intervention-interaction effects. Results showed that both the low emotional well-being group and normal emotional well-being group had equal glycemic outcomes during the CGM phase. High diabetes distress and elevated fear of hypoglycemia did not result in significant interaction effects for glycemic outcomes. This study demonstrated that CGM is equally effective in terms of glycemic improvements in high versus low distressed patients with T1D and impaired awareness of hypoglycemia.

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.

Severe hypoglycemia, impaired awareness of hypoglycemia, and self-monitoring in adults with type 1 diabetes: Results from Diabetes MILES-Australia

AIMS

To assess prevalence of severe hypoglycemia, awareness and symptoms of hypoglycemia, and their associations with self-monitoring of blood glucose.

METHODS

Diabetes MILES-Australia Study participants completed validated questionnaires and study-specific items.

RESULTS

Of 642 adults with type 1 diabetes, 21% reported ≥1 severe hypoglycemic event in the past six months, and 21% reported impaired awareness of hypoglycemia (IAH). Severe hypoglycemia was increased four-fold for those with IAH compared with intact awareness (1.4±3.9 versus 0.3±1.0). Of those with IAH, 92% perceived autonomic and 88% neuroglycopenic symptoms, albeit at lower glucose thresholds compared to people with intact awareness. Those with IAH were more likely to perceive both symptom types at the same glucose level or to perceive neuroglycopenic symptoms first (all p<0.001). Eighteen percent with IAH treated hypoglycemia only when they perceived symptoms and another 18% only when their capillary glucose was <3.0mmol/L.

CONCLUSIONS

One in five adults with type 1 diabetes had IAH or experienced severe hypoglycemia in the past sixmonths. Total loss of hypoglycemia symptoms was rare; most people with IAH retained autonomic symptoms, perceived at relatively low glucose levels. Frequent self-monitoring of blood glucose prompted early recognition and treatment of hypoglycemia, suggesting severe hypoglycemia risk can be minimized.

Naltrexone for treatment of impaired awareness of hypoglycemia in type 1 diabetes: A randomized clinical trial

AIMS

Impaired awareness of hypoglycemia (IAH) is a limiting factor in the treatment of type 1 diabetes (T1D) and is a challenging condition to reverse. The objective of this study was to test the hypothesis that naltrexone therapy in subjects with T1D and IAH will improve counterregulatory hormone response and recognition of hypoglycemia symptoms during hypoglycemia.

METHODS

We performed a pilot randomized double blind trial of 4weeks of naltrexone therapy (n=10) or placebo (n=12) given orally in subjects with T1D and IAH. Outcome measures included hypoglycemia symptom scores, counterregulatory hormone levels and thalamic activation as measured by cerebral blood flow using MRI during experimental hypoglycemia in all subjects before and after 4weeks of intervention.

RESULTS

After 4weeks of therapy with naltrexone or placebo, no significant differences in response to hypoglycemia were seen in any outcomes of interest within each group.

CONCLUSIONS

In this small study, short-term treatment with naltrexone did not improve recognition of hypoglycemia symptoms or counterregulatory hormone response during experimental hypoglycemia in subjects with T1D and IAH. Whether this lack of effect is related to the small sample size or due to the dose, the advanced stage of study population or the drug itself should be the subject of future investigation.

Brain glucose metabolism during hypoglycemia in type 1 diabetes: insights from functional and metabolic neuroimaging studies

Hypoglycemia is the most frequent complication of insulin therapy in patients with type 1 diabetes. Since the brain is reliant on circulating glucose as its main source of energy, hypoglycemia poses a threat for normal brain function. Paradoxically, although hypoglycemia commonly induces immediate decline in cognitive function, long-lasting changes in brain structure and cognitive function are uncommon in patients with type 1 diabetes. In fact, recurrent hypoglycemia initiates a process of habituation that suppresses hormonal responses to and impairs awareness of subsequent hypoglycemia, which has been attributed to adaptations in the brain. These observations sparked great scientific interest into the brain’s handling of glucose during (recurrent) hypoglycemia. Various neuroimaging techniques have been employed to study brain (glucose) metabolism, including PET, fMRI, MRS and ASL. This review discusses what is currently known about cerebral metabolism during hypoglycemia, and how findings obtained by functional and metabolic neuroimaging techniques contributed to this knowledge.

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.