Hypoglycemia: from the laboratory to the clinic

Metabolic Control, Diabetic Complications and Drug Therapy in a Cohort of Patients with Type 1 and Type 2 Diabetes in Secondary and Tertiary Care between 2004 and 2019

This paper studies the features of metabolic parameters, diabetic complications and drug therapy of a single-centre cohort of patients with type 1 diabetes (T1DM) or type 2 diabetes (T2DM) in secondary care and tertiary care over a 15-year period.

METHODS

Retrospective cross-sectional analysis of four single-centre cohorts between 2004 and 2019. All patients with T1DM or T2DM in secondary care (n = 5571) or tertiary care (n = 2001) were included. Statistical analyses were performed using linear mixed models.

RESULTS

Diabetes duration increased in both patients with T1DM and T2DM in secondary care and tertiary care (p < 0.001). Patients in secondary care consistently showed good glycaemic control, while patients in tertiary care showed inadequate glycaemic control. All four cross-sectional cohorts showed a significant increase in the prevalence of nephropathy over time and three out of four cohorts (T1DM and T2DM in secondary care and T2DM in tertiary care) showed an increase in the prevalence of neuropathy (all p < 0.001). The incidence of severe hypoglycaemia was consistently low. The use of insulin pumps and insulin analogues in the therapy of T1DM increased significantly.

CONCLUSIONS

The increased prevalence of complications is likely due to older age and longer diabetes duration. Low rates of hypoglycaemia, lower limb amputations and good glycaemic control in secondary care patients indicate a good structure of patient care.

"It's embarrassing. I get angry. I get frustrated.": Understanding severe hypoglycemia and glucagon usage from the perspectives of people with type 1 diabetes

Introduction

This study characterized the emotional impact of severe hypoglycemia, views of glucagon, and barriers to glucagon use from the perspective of adults with type 1 diabetes (T1D).

Methods

Participants included individuals recruited from the T1D Exchange online community. The current study conducted 7 focus groups consisting of adults with T1D (N = 38, average age 49.4, SD = 16.11 years). Average duration of diabetes was 34.4 years (SD = 17.3) and average self-reported A1c was 6.8 % (SD = 0.7). Focus group interviews were recorded, transcribed, and thematically analyzed.

Results

A range of emotions was expressed about severe hypoglycemia including fear, anxiety, stress, frustration, shame, and embarrassment. Participants frequently identified prescription cost and insurance deductibles as barriers to glucagon use. Participants were also concerned about ease of administration-how difficult it is to prepare the glucagon in an emergency. Many participants expressed a preference for auto-injectables over nasal administration. Timing of glucagon action and time to recovery were high priorities. Some participants, while they had not self-administered glucagon, were interested in a mini-dose glucagon they could self-administer. They also identified desirable characteristics of glucagon treatment including reduced cost, long shelf-life, and quick activation.

Conclusions

These results highlight the attitudes about severe hypoglycemia and emergency treatment with glucagon. Healthcare professionals should assess glucagon training needs and knowledge when they meet with their patients with diabetes.

Emergency Glucagon: a Focused Review of Psychosocial Experiences of Rescue Drugs for Type 1 Diabetes

PURPOSE OF REVIEW

The purpose of this paper is to describe rescue glucagon types, safety, efficacy, and preferences, as well as to review articles regarding emergency glucagon usage, severe hypoglycemia, and the emotions of both phenomena. We conducted a review of current literature on glucagon usage and the emotional impact of severe hypoglycemia on people with diabetes (PwD) and the caregivers of people with type 1 diabetes (T1D).

RECENT FINDINGS

Minimal research exists pertaining to glucagon and severe hypoglycemic experiences in PwD, which is troubling considering the severity of risks and possible side effects. Recent articles described negative emotions such as fear, anxiety, stress, helplessness, shame, embarrassment, loneliness, frustration, hopefulness, and uncertainty surrounding glucagon usage. There is scarce research regarding PwD's emotions surrounding severe hypoglycemia and rescue glucagon use. Additional research is needed to investigate the emotions and feelings people with T1D and their caregivers' experience pertaining to severe hypoglycemia and emergency glucagon use.

Conversations and Reactions Around Severe Hypoglycemia (CRASH) Study: Results From People With Diabetes and Caregivers in the United States

A survey was conducted in eight countries to examine conversations around, and experiences and treatments during, severe hypoglycemia among people with diabetes and caregivers of people with diabetes. This article reports a subgroup analysis from the United States involving 219 people with diabetes and 210 caregivers. Most respondents (79.7%) did not use professional health care services during their most recent severe hypoglycemic event, and 40.3% did not report the event to their health care providers at a subsequent follow-up visit. Hypoglycemic events left respondents feeling scared (70.9%), unprepared (42.7%), and helpless (46.9%). These clinically important psychosocial impacts on people with diabetes and caregivers underscore the need for conversations about hypoglycemia prevention and management.

Sleep and hypoglycaemia symptom perception in adults with type-1 diabetes mellitus: A mixed-methods review

AIMS

The study aims to review, synthesize and integrate primary research on the relationship between sleep and hypoglycaemia symptom perception in adults with type-1 diabetes.

DESIGN

This mixed-methods review follows a convergent segregated approach to synthesis and integration of qualitative and quantitative evidence.

DATA SOURCES

With assistance of a biomedical librarian, a search of four databases was conducted (PubMed, CINAHL, Embase and PsycINFO) in June 2020. The review included primary research measuring sleep and hypoglycaemia symptom perception in adults (age ≥ 18 years) with type-1 diabetes in English. Studies that exclusively addressed children, type-2 diabetes or outcomes unrelated to sleep and hypoglycaemia symptom perception were excluded.

REVIEW METHODS

Screening focused on title and abstract review (n = 624). Studies not excluded after screening (n = 35) underwent full-text review. References of each study selected for inclusion (n = 6) were hand searched with one study added. All studies included in the review (n = 7) were critically appraised with JBI Critical Appraisal tools, and then data were extracted with systematic evaluation.

RESULTS

Quantitative synthesis found sleep reduces the magnitude of detectable symptoms and one's capacity to detect them. Qualitative synthesis found that individuals with type-1 diabetes perceive unpredictable severity, frequency and awareness of symptoms while asleep as an oppressive, lingering threat. Integration of findings highlights the troublesome duality of sleep's relationship with hypoglycaemia symptom perception.

CONCLUSIONS

Sleep presents a challenging time for individuals with type-1 diabetes. Further research examining the relationship between sleep and hypoglycaemia symptom perception is recommended as the number of studies limits this review.

IMPACT

Symptom perception is the main physiologic defense against severe hypoglycaemia in type-1 diabetes. This review found that sleep's relationship with hypoglycaemia symptoms has unique physiological and psychological components to address when providing comprehensive care. This review may inform future lines of inquiry that develop into interventions, improvements in practice and risk reduction for hypoglycaemia-related complications.

Hospitalization for hypoglycaemia in people with diabetes in Denmark, 1997-2017: Time trends in incidence and HbA1c and glucose-lowering drug use before and after hypoglycaemia

Objective

To assess incidence trends of first hospitalization for hypoglycaemia in Denmark and to examine HbA_1c levels and glucose‐lowering drug use before and after hospitalization among individuals with type 1 or type 2 diabetes.

Research Design and Methods

We performed a population‐based study linking diagnosis, prescription and laboratory data. Standardized incidence of first hospitalization for hypoglycaemia in Denmark was assessed for each calendar year 1997–2017. HbA1c and glucose‐lowering drug use was compared with age‐ and sex‐matched diabetes comparisons without hospitalization for hypoglycaemia.

Results

The annual age‐ and sex‐standardized incidence rate of first hospitalization for hypoglycaemia per 100,000 person‐years increased during 1997–2003 (from 17.7 to 30.3 per 100,000 person‐years), remained stable until 2010 (30.4) and gradually declined until 2017 (22.0). During this period, we identified 3,479 people with type 1 diabetes and 15,329 people with type 2 diabetes experiencing first hospitalization for hypoglycaemia. Both diabetes groups experienced a mean HbA1c decrease of ~12%–15% in the months preceding first hospitalization, followed by a gradually increasing HbA1c afterwards. People with type 1 diabetes and hospitalization used similar insulin therapies as those without hospitalization. People with type 2 diabetes and hospitalization more often received insulin (55%) than comparisons (45%), and 45% discontinued insulin or stopped all glucose‐lowering therapy after first hospitalization.

Conclusions

Incidence of hospitalizations for hypoglycaemia has declined by one fourth the last decade in the Danish population. A HbA1c decrease precedes first hospitalization for hypoglycaemia in individuals with diabetes, and profound changes in glucose‐lowering drug therapy for type 2 diabetes occur after hospitalization.

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.

A Human Randomized Controlled Trial Comparing Metabolic Responses to Single and Repeated Hypoglycemia in Type 1 Diabetes

AIMS

Hypoglycemia hinders optimal glycemic management in type 1 diabetes (T1D). Long diabetes duration and hypoglycemia impair hormonal counter-regulatory responses to hypoglycemia. Our study was designed to test whether (1) the metabolic responses and insulin sensitivity are impaired, and (2) whether they are affected by short-lived antecedent hypoglycemia in participants with T1D.

MATERIALS AND METHODS

In a randomized, crossover, 2x2 factorial design, 9 male participants with T1D and 9 comparable control participants underwent 30 minutes of hypoglycemia (p-glucose < 2.9 mmol/L) followed by a euglycemic clamp on 2 separate interventions: with and without 30 minutes of hypoglycemia the day before the study day.

RESULTS

During both interventions insulin sensitivity was consistently lower, while counter-regulatory hormones were reduced, with 75% lower glucagon and 50% lower epinephrine during hypoglycemia in participants with T1D, who also displayed 40% lower lactate and 5- to 10-fold increased ketone body concentrations following hypoglycemia, whereas palmitate and glucose turnover, forearm glucose uptake, and substrate oxidation did not differ between the groups. In participants with T1D, adipose tissue phosphatase and tensin homolog (PTEN) content, hormone-sensitive lipase (HSL) phosphorylation, and muscle glucose transporter type 4 (GLUT4) content were decreased compared with controls. And antecedent hypoglycemic episodes lasting 30 minutes did not affect counter-regulation or insulin sensitivity.

CONCLUSIONS

Participants with T1D displayed insulin resistance and impaired hormonal counter-regulation during hypoglycemia, whereas glucose and fatty acid fluxes were intact and ketogenic responses were amplified. We observed subtle alterations of intracellular signaling and no effect of short-lived antecedent hypoglycemia on subsequent counter-regulation. This plausibly reflects the presence of insulin resistance and implies that T1D is a condition with defective hormonal but preserved metabolic responsiveness to short-lived hypoglycemia.

Reduction of Severe Hypoglycaemia in People with Type 2 Diabetes after a Structured Inpatient Intervention

OBJECTIVE

The aim of this longitudinal study was to assess outcomes before and one year after participation in a structured inpatient intervention including participation in an education programme for people with type 2 diabetes.

METHODS

In 2014, 81 individuals, who were admitted to optimise insulin therapy, participated in a structured inpatient intervention and were invited to participate in a follow-up visit after one year.

RESULTS

Seventy participants (46.9% female, age 68.3 y, diabetes duration 17.9 y, HbA1c 9.7%/82.5 mmol/mol) were followed-up after 1.2 y (3 died by non-diabetic causes, 8 declined/were not available). HbA1c decreased by 1.1% (p<0.001) without change of insulin dose (79.7 vs. 79.3 IU, n.s.) or BMI (33.6 vs. 33.8 kg/m², n.s.). 5 people admitted because of severe hypoglycaemia (one person with 5 episodes and 4 with one episode in the year prior to participation) did not experience another event in the evaluation period, nor did anyone in the rest of the cohort (frequency of severe hypoglycaemia 0.12 events/year before and 0.0 after intervention).

CONCLUSIONS

In people admitted for optimising insulin therapy or severe hypoglycaemia, metabolic control improved substantially and frequency of severe hypoglycaemia was significantly reduced after participation in a structured inpatient intervention. Reasons could be motivational and better adapted eating habits, tailoring individual therapy solutions and deescalating diabetes therapy in people after severe hypoglycaemia.

Adequate Structured Inpatient Diabetes Intervention in People With Type 1 Diabetes Improves Metabolic Control and Frequency of Hypoglycaemia

OBJECTIVE

Several studies evaluated inpatient diabetes teaching and treatment programmes (DTTP) in diabetes type 1 (DM1) many years ago, but in these studies insulin treatment was not yet intensified before the DTTP. Today, most patients are already on intensified insulin treatment before entering a DTTP. The aim of this trial was to evaluate the outcome one year after participation in an inpatient intervention including a DTTP in a longitudinal study.

METHODS

109 patients participated in an inpatient intervention in 2014. All individuals were invited to participate in an outpatient follow-up visit after one year.

RESULTS

Ninety participants (52.2% female, age 48.0 y, diabetes duration 19.1 y, 31.1% CSII, HbA1c 7.9% / 63.3 mmol/mol) were followed-up after 1.2±0.3 y [1 died, 18 declined / were not available]. 83 / 90 individuals participated to optimise diabetes therapy, 7 / 90 had newly-diagnosed DM1. In the optimisation group, HbA1c decreased by 0.4% (p=0.009) without change of insulin dose (54 IU/day before and after) or BMI (26 kg/m² before and after). In people with baseline HbA1c ≥7.5% (n=26 / 83), HbA1c decreased by 0.9%. The frequency of severe hypoglycaemia decreased from 0.22 to 0.05 events / year (p=0.045). In people with frequent non severe hypoglycaemia (n=8), events decreased from 4.5±2.0 to 2.8±0.9 / week (p=0.358). Systolic (-6.5 mmHg, p=0.035) and diastolic (-3.4 mmHg, p=0.003) blood pressure improved without change of number of antihypertensive medication (1.9±2.1 vs. 1.8±2.0, p=0.288).

CONCLUSIONS

In people with DM1, metabolic control improved after the inpatient intervention without increasing insulin dosage or BMI. The inpatient intervention remains effective to substantially improve metabolic control under the present circumstances of care.

Evaluation of diabetes care management in primary clinics based on the guidelines of American Diabetes Association

OBJECTIVE

There is a rapid increase in the incidence of diabetes mellitus in Saudi Arabia. Diabetes management is an essential constituent to prevent prognosis of diabetes complications. The main objective of this study was to assess diabetes care in primary clinics based on the guidelines of American Diabetes Association (ADA).

METHODS

A retrospective study at King Khaled University Hospitals, Riyadh, Saudi Arabia. A total of 200 patients were randomly selected from the databases of primary care clinics. An evaluation checklist was created based on the ADA treatment guidelines such as medical history, physical examination, laboratory evaluation, and referrals.

RESULTS

The result showed that elements achieving the ADA targets for overall care were medical history (44.9%), physical examination (59.6%), laboratory evaluation (36.3%), and referrals (19.3%). The other subelement indicators such as referral to diabetes self-management education clinics (10%), dental examination (2%), HbA1c regular monitoring (33.5%), and blood pressure determination (100%) were documented with adherence to ADA standards.

CONCLUSIONS

Diabetes management standards are an essential element in the success of the management plan. Most of the elements examined are not in full compliance with the ADA standard. Continues monitoring and self-review are recommended.

Effect of 48 h Fasting on Autonomic Function, Brain Activity, Cognition, and Mood in Amateur Weight Lifters

Objectives. The acute fasting-induced cardiovascular autonomic response and its effect on cognition and mood remain debatable. Thus, the main purpose of this study was to estimate the effect of a 48 h, zero-calorie diet on autonomic function, brain activity, cognition, and mood in amateur weight lifters. Methods. Nine participants completed a 48 h, zero-calorie diet program. Cardiovascular autonomic function, resting frontal brain activity, cognitive performance, and mood were evaluated before and after fasting. Results. Fasting decreased (p < 0.05) weight, heart rate, and systolic blood pressure, whereas no changes were evident regarding any of the measured heart rate variability indices. Fasting decreased (p < 0.05) the concentration of oxygenated hemoglobin and improved (p < 0.05) mental flexibility and shifting set, whereas no changes were observed in working memory, visuospatial discrimination, and spatial orientation ability. Fasting also increased (p < 0.05) anger, whereas other mood states were not affected by it. Conclusions. 48 h fasting resulted in higher parasympathetic activity and decreased resting frontal brain activity, increased anger, and improved prefrontal-cortex-related cognitive functions, such as mental flexibility and set shifting, in amateur weight lifters. In contrast, hippocampus-related cognitive functions were not affected by it.

Saxagliptin co-therapy in C-peptide negative Type 1 diabetes does not improve counter-regulatory responses to hypoglycaemia

AIMS

To test the hypothesis that dipeptidyl peptidase-4 inhibition in C-peptide negative Type 1 diabetes would reduce glucose variability and exposure to hypoglycaemia and therefore may indirectly enhance counter-regulatory responses to subsequent hypoglycaemia.

METHODS

We conducted a 12-week double-blind, randomized, placebo-controlled crossover study. The study was conducted in a tertiary hospital outpatient clinic, with additional studies performed in a clinical research centre. After obtaining informed consent, we recruited 14 subjects with moderately well controlled Type 1 diabetes (HbA1c 64 ± 2 mmol/mol) of long duration (20.5 ± 2.7 years). The subjects received 12 weeks' therapy with oral saxagliptin (5 mg) or placebo. Glucose variability, assessed via continuous glucose monitoring, together with frequency of hypoglycaemia, hypoglycaemia awareness and symptomatic, cognitive and counter-regulatory hormone responses to experimental hypoglycaemia, were assessed. Additional outcome measures included HbA1c level, weight, total daily insulin dose and adverse events.

RESULTS

Saxagliptin co-therapy did not reduce glucose variability (low blood glucose index, average daily risk range), hypoglycaemia frequency or awareness and did not improve counter-regulatory hormonal responses during experimental hypoglycaemia (area under the curve for adrenaline 25 775 vs. 24 454, for placebo vs saxagliptin, respectively; P = 0.76).

CONCLUSIONS

No additional benefit of dipeptidyl peptidase-4 inhibition co-therapy with saxagliptin in the management of Type 1 diabetes was observed.

Insights into the role of neuronal glucokinase

Glucokinase is a key component of the neuronal glucose-sensing mechanism and is expressed in brain regions that control a range of homeostatic processes. In this review, we detail recently identified roles for neuronal glucokinase in glucose homeostasis and counterregulatory responses to hypoglycemia and in regulating appetite. We describe clinical implications from these advances in our knowledge, especially for developing novel treatments for diabetes and obesity. Further research required to extend our knowledge and help our efforts to tackle the diabetes and obesity epidemics is suggested.

Effect of an avocado oil-enhanced diet ( Persea americana ) on sucrose-induced insulin resistance in Wistar rats

A number of studies have been conducted to evaluate the effects of vegetable oils with varying percentages of monounsaturated and polyunsaturated fatty acids on insulin resistance. However, there is no report on the effect of avocado oil on this pathologic condition. The aim of this work was to evaluate the effect of avocado oil on sucrose-induced insulin resistance in Wistar rats. An experimental study was carried out on Wistar rats that were randomly assigned into six groups. Each group received a different diet over an 8-week period (n = 11 in each group): the control group was given a standard diet, and the other five groups were given the standard feed plus sucrose with the addition of avocado oil at 0%, 5%, 10%, 20%, and 30%, respectively. Variables were compared using Student t test and analysis of variance. Statistically significant difference was considered when p < 0.05. Rats that were given diets with 10% and 20% avocado oil showed lower insulin resistance (p = 0.022 and p = 0.024, respectively). Similar insulin resistance responses were observed in the control and 30% avocado oil addition groups (p = 0.85). Addition of 5–30% avocado oil lowered high sucrose diet-induced body weight gain in Wistar rats. It was thus concluded that glucose tolerance and insulin resistance induced by high sucrose diet in Wistar rats can be reduced by the dietary addition of 5–20% avocado oil.

Minimizing Hypoglycemia in Diabetes

Hypoglycemia caused by treatment with a sulfonylurea, a glinide, or insulin coupled with compromised defenses against the resulting falling plasma glucose concentrations is a problem for many people with diabetes. It is often recurrent, causes significant morbidity and occasional mortality, limits maintenance of euglycemia, and impairs physiological and behavioral defenses against subsequent hypoglycemia. Minimizing hypoglycemia includes acknowledging the problem; considering each risk factor; and applying the principles of intensive glycemic therapy, including drug selection and selective application of diabetes treatment technologies. For diabetes health-care providers treating most people with diabetes who are at risk for or are suffering from iatrogenic hypoglycemia, these principles include selecting appropriate individualized glycemic goals and providing structured patient education to reduce the incidence of hypoglycemia. This is typically combined with short-term scrupulous avoidance of hypoglycemia, which often will reverse impaired awareness of hypoglycemia. Clearly, the risk of hypoglycemia is modifiable.

Hypoglycemia-associated changes in the electroencephalogram in patients with type 1 diabetes and normal hypoglycemia awareness or unawareness

Hypoglycemia is associated with increased activity in the low-frequency bands in the electroencephalogram (EEG). We investigated whether hypoglycemia awareness and unawareness are associated with different hypoglycemia-associated EEG changes in patients with type 1 diabetes. Twenty-four patients participated in the study: 10 with normal hypoglycemia awareness and 14 with hypoglycemia unawareness. The patients were studied at normoglycemia (5-6 mmol/L) and hypoglycemia (2.0-2.5 mmol/L), and during recovery (5-6 mmol/L) by hyperinsulinemic glucose clamp. During each 1-h period, EEG, cognitive function, and hypoglycemia symptom scores were recorded, and the counterregulatory hormonal response was measured. Quantitative EEG analysis showed that the absolute amplitude of the θ band and α-θ band up to doubled during hypoglycemia with no difference between the two groups. In the recovery period, the θ amplitude remained increased. Cognitive function declined equally during hypoglycemia in both groups and during recovery reaction time was still prolonged in a subset of tests. The aware group reported higher hypoglycemia symptom scores and had higher epinephrine and cortisol responses compared with the unaware group. In patients with type 1 diabetes, EEG changes and cognitive performance during hypoglycemia are not affected by awareness status during a single insulin-induced episode with hypoglycemia.

Restoration of self-awareness of hypoglycemia in adults with long-standing type 1 diabetes: hyperinsulinemic-hypoglycemic clamp substudy results from the HypoCOMPaSS trial

OBJECTIVE

Impaired awareness of hypoglycemia (IAH) and defective counterregulation significantly increase severe hypoglycemia risk in type 1 diabetes (T1D). We evaluated restoration of IAH/defective counterregulation by a treatment strategy targeted at hypoglycemia avoidance in adults with T1D with IAH (Gold score ≥4) participating in the U.K.-based multicenter HypoCOMPaSS randomized controlled trial.

RESEARCH DESIGN AND METHODS

Eighteen subjects with T1D and IAH (mean ± SD age 50 ± 9 years, T1D duration 35 ± 10 years, HbA1c 8.1 ± 1.0% [65 ± 10.9 mmol/mol]) underwent stepped hyperinsulinemic-hypoglycemic clamp studies before and after a 6-month intervention. The intervention comprised the HypoCOMPaSS education tool in all and randomized allocation, in a 2 × 2 factorial study design, to multiple daily insulin analog injections or continuous subcutaneous insulin infusion therapy and conventional glucose monitoring or real-time continuous glucose monitoring. Symptoms, cognitive function, and counterregulatory hormones were measured at each glucose plateau (5.0, 3.8, 3.4, 2.8, and 2.4 mmol/L), with each step lasting 40 min with subjects kept blinded to their actual glucose value throughout clamp studies.

RESULTS

After intervention, glucose concentrations at which subjects first felt hypoglycemic increased (mean ± SE from 2.6 ± 0.1 to 3.1 ± 0.2 mmol/L, P = 0.02), and symptom and plasma metanephrine responses to hypoglycemia were higher (median area under curve for symptoms, 580 [interquartile range {IQR} 420-780] vs. 710 [460-1,260], P = 0.02; metanephrine, 2,412 [-3,026 to 7,279] vs. 5,180 [-771 to 11,513], P = 0.01). Glycemic threshold for deterioration of cognitive function measured by four-choice reaction time was unchanged, while the color-word Stroop test showed a degree of adaptation.

CONCLUSIONS

Even in long-standing T1D, IAH and defective counterregulation may be improved by a clinical strategy aimed at hypoglycemia avoidance.

Evaluation of a treatment and teaching refresher programme for the optimization of intensified insulin therapy in type 1 diabetes

OBJECTIVE

Evaluation of an ambulatory diabetes teaching and treatment refresher programme (DTTP) for the optimization of intensified insulin therapy in patients with type 1 diabetes (refresher course).

METHODS

85 outpatients took part in this prospective multicentre trial. Metabolic and psychosocial data were analyzed at baseline (V1), 6 weeks (V2) and 12 months after DTTP (V3).

RESULTS

In patients with baseline HbA1c>7% (88%), HbA1c decreased by 0.36% (p=0.004). The percentage of patients with HbA1c≤7% increased from 21.3 to 34.9% and with HbA1c above 10% decreased from 6.6 to 1.6% at V3. The incidence of hypoglycaemia decreased significantly: non severe hypoglycaemia from 3.31 to 1.39 episodes/pat/week (p=0.001) and severe hypoglycaemia from 0.16 to 0.03 episodes/pat/year (p=0.02). The treatment satisfaction increased by +10 of maximal ±18 points. The negative influence of diabetes on quality of life decreased from -1.93 to -1.69 points (p=0.031).

CONCLUSION

In a group of patients with moderately controlled diabetes type 1 who were already treated with intensified insulin therapy, metabolic control, treatment satisfaction and quality of life were improved after participation in an ambulatory DTTP without increasing insulin dosage, number of injections or insulin species.

PRACTICE IMPLICATIONS

This DTTP is effective for the optimization of intensified insulin therapy.

Omitting Follow-up Food After Initial Hypoglycaemic Treatment Does not Increase the Likelihood of Repeat Hypoglycaemia

INTRODUCTION

Guidelines for self-treatment of hypoglycaemia specify initial treatment with quick-acting carbohydrate until blood glucose levels normalize and then follow-up with longer-acting carbohydrate. The few studies investigating follow-up show 29-57% omission or undertreatment with follow-up carbohydrate but do not investigate the association of this with repeat hypoglycaemia. This study aimed to develop, validate and administer a questionnaire to delineate this association. The timeframe targeted was 2 h post primary hypoglycaemic event (PPHE), the time influenced by long-acting carbohydrate.

METHODS

A questionnaire was generated, test-retest reliability assessed, and it was piloted on convenience samples from the target population. The final version was administered to all insulin-treated individuals attending an outpatient diabetes clinic over 4 weeks (169).

RESULTS

Questionnaire development: readability (69.6-standard/easy), test-retest reliability (Cohen's kappa 0.57-0.91) and return rate (72.2%) were all acceptable. Questionnaire data: questionnaires were returned by 122 participants (63 males/59 females). Method of insulin administration was subcutaneous insulin injections (91%) and continuous subcutaneous insulin infusion (CSII) (9%). Repeat hypoglycaemia within 2 h PPHE was reported by 8.2% of respondents. There was no significant difference for age, gender and diabetes duration between those reporting repeat hypoglycaemia and those without. Consumption of follow-up longer-acting carbohydrate was reported by 58.2% of responders with 48% of these using long-acting and 52% medium-acting carbohydrate foods. Method of insulin administration and consumption of follow-up food were significantly associated with repeat hypoglycaemia (P = 0.015, 0.039) but presence or absence of symptoms and duration of action of carbohydrate were not significantly associated (P = 0.103, 0.629). Hierarchical logistic regression analysis showed omission of follow-up food PPHE was not a significant predictor of increased likelihood of repeat hypoglycaemia within 2 h PPHE, irrespective of method of insulin administration (P = 0.085).

CONCLUSION

This study supports guidelines that recommend judicious, rather than routine use of follow-up longer-acting carbohydrate PPHE.

A retrospective study on the incidence and risk factors of severe hypoglycemia in primary care

AIMS

To investigate the incidence and risk factors of severe hypoglycemia (SH) in primary care. SH was defined as hypoglycemia with coma, or the need of glucose or glucagon injection.

METHODS

We performed a cross-sectional retrospective study in patients with diabetes treated in primary care in Germany. We analyzed an unselected sample of participants with type 1 (n = 373) and type 2 diabetes (n = 4481) who participated in an insurance plan from the health care insurer Deutsche BKK. Data of participants with type 1 diabetes are as follows: women, n = 155 (42%); age, 49±16 years; diabetes duration, 20+13 years; BMI, 28±6 kg/m2; GHb, 7.1+1.5%; GHb≤7%, n = 263 (71%); GHb≥8.5%, n = 48 (13%). Data of participants with type 2 diabetes: women, n = 1979 (44%); age, 66±10 years; diabetes duration, 8±7 years; BMI, 30±5 kg/m2; GHb, 6.6±1.3%; GHb≤7%, n = 3747 (84%); GHb≥8.5%, n = 360 (8%); insulin therapy, n = 1175 (26%).

RESULTS

The incidence of SH in type 1 diabetes: 1.3% (CI: 0.4%, 3.1%) per year; type 2 diabetes with insulin therapy: 0.9% (CI: 0.5%, 1.7%); without insulin therapy: 0.3% (CI: 0.1%, 0.6%). The event rate was 0.02 SH per patient/year in type 1 diabetes and 0.01 in type 2 diabetes, respectively. Low BMI, GHb, insulin therapy and female gender were associated with an increased risk of SH.

CONCLUSIONS

In primary care, patients with diabetes can achieve good glycemic control with very rare events of SH. Due to low incidence, SH would have been an inappropriate parameter to evaluate the outcome quality of diabetes therapy in primary care.

NMDA receptor blockade by memantine does not prevent adaptation to recurrent hypoglycaemia in healthy men

AIMS

Recurrent hypoglycaemia leads to an attenuation of hypoglycaemic symptoms and hormonal counterregulatory responses. This phenomenon poses a severe problem in the treatment of patients with diabetes mellitus, but the underlying neuroendocrine mechanisms are unclear. On the basis of animal experimental findings, we hypothesized that counterregulatory attenuation represents a basic adaptive learning process relying on synaptic long-term potentiation or depression. If so, attenuation should be prevented by blocking glutamatergic N-methyl-D-aspartate (NMDA) receptors.

METHODS

Sixteen healthy young men participated in two conditions, separated by 4 weeks. Participants received the NMDA antagonist memantine over 5 days (15 mg/day) in one condition and placebo in the other one. After 3 days of drug administration, participants underwent two hypoglycaemic clamps on day 4 and another one on day 5. We assessed blood concentrations of counterregulatory hormones (cortisol, ACTH, epinephrine, norepinephrine, growth hormone and glucagon) as well as subjective symptoms of hypoglycaemia and word-list recall as an indicator of short-term memory.

RESULTS

Counterregulatory responses of all hormones as well as neuroglycopenic and autonomic symptom ratings showed robust attenuation following the third as compared to the first hypoglycaemia (p < 0.05). NMDA receptor antagonization by memantine impaired memory function but did not alter any neuroendocrine measure of counterregulatory attenuation (p > 0.17).

CONCLUSIONS

Attenuation of the endocrine as well as symptomatic counterregulatory response to recurrent hypoglycaemia is not prevented by the NMDA receptor blocker memantine. Our results do not support the view that adaptation to repeated hypoglycaemia relies on NMDA receptor-mediated plastic processes involving long-term potentiation or depression.

Acute hypoglycemia causes depressive-like behaviors in mice

Reports in humans advocate a link between hypoglycemia and altered mood. Such observations, however, have not been mechanistically explored. Here we examined depressive-like behaviors in mice resulting from acute hypoglycemia. Mice were fasted for 12 hours and then administered intraperitoneal insulin to induce a blood glucose nadir of 50 mg/dL at 0.75 hour after injection that by 2 hours postinjection had returned to normal. The behaviors of locomotion, forced swim, saccharin preference, and novel object recognition were subsequently examined. Mice made hypoglycemic showed depressive-like behaviors 24 hours after resolution of hypoglycemia as evidenced by increased immobility in the forced swim test (FST) and reduced saccharin preference. Movement and memory were not impacted by hypoglycemia 24 hours after its resolution. By 48 hours posthypoglycemia, depressive-like behaviors resolved. In contrast, neither peripheral insulin administration without resultant hypoglycemia nor intracerebroventricular insulin administration altered performance in the FST. The antidepressants fluoxetine and desipramine prevented hypoglycemia-induced immobility in the FST, as did the antiadrenergic agents phentolamine, metoprolol, and butoxamine. Epinephrine and norepinephrine administration caused increased immobility in the FST at 24 hours postadministration that subsequently resolved by 48 hours. These data indicate that, in mice, acute hypoglycemia through adrenergic pathways caused depressive-like behaviors that exist well beyond the resolution of hypoglycemia.

Update in the CNS response to hypoglycemia

Hypoglycemia remains a major clinical issue in the management of people with type 1 and type 2 diabetes. Research in basic science is only beginning to unravel the mechanisms that: 1) underpin the detection of hypoglycemia and initiation of a counterregulatory defense response; and 2) contribute to the development of defective counterregulation in both type 1 and type 2 diabetes, particularly after prior exposure to repeated hypoglycemia. In animal studies, the central nervous system has emerged as key to these processes. However, bench-based research needs to be translated through studies in human subjects as a first step to the future development of clinical intervention. This Update reviews studies published in the last 2 yr that examined the central nervous system effects of hypoglycemia in human subjects, largely through neuroimaging techniques, and compares these data with those obtained from animal studies and the implications for future therapies. Based on these studies, it is increasingly clear that our understanding of how the brain responds and adapts to recurrent hypoglycemia remains very limited. Current therapies have provided little evidence that they can prevent severe hypoglycemia or improve hypoglycemia awareness in type 1 diabetes. There remains an urgent need to increase our understanding of how and why defective counterregulation develops in type 1 diabetes in order for novel therapeutic interventions to be developed and tested.

Decreased vascular endothelial growth factor response to acute hypoglycemia in type 2 diabetic patients with hypoglycemic coma

INTRODUCTION

Plasma vascular endothelial growth factor (VEGF) was shown to increase during acute hypoglycemia and could mediate rapid adaptation of the brain. In this study we examined the neuroendocrine response in patients with type 2 diabetes mellitus (T2DM) in hypoglycemic coma or with acute neuroglycopenic symptoms.

METHODS

We prospectively studied 135 consecutive T2DM patients admitted for severe hypoglycemia during a 2-year period. We collected clinical variables and measured plasma concentrations of VEGF, epinephrine, norepinephrine, cortisol and growth hormone at admission and 30min afterwards.

RESULTS

Thirty two patients developed hypoglycemic coma and 103 did not lose consciousness. Median plasma VEGF level of coma patients was 3.1-fold lower at baseline than that of non-coma patients, and even 5.3-fold lower 30min afterwards. Plasma epinephrine concentration was significantly lower just at baseline in coma patients. On the contrary, there were no differences in concentrations of the other hormones. Multivariate logistic regression analysis showed that VEGF concentration (OR 0.68; CI 0.51-0.95) was a protective factor against the development of coma.

CONCLUSIONS

VEGF and epinephrine responses to acute hypoglycemia are reduced in T2DM patients who develop hypoglycemic coma. An increased plasma VEGF concentration appeared to be a protective factor against the development of hypoglycemic coma.

Glucose counterregulatory responses to hypoglycemia

The brain relies almost exclusively on glucose for fuel. Therefore, adequate uptake of glucose from the plasma is key for normal brain function and survival. Despite wide variations in glucose flux (i.e., fed state, fasting state, etc), blood glucose is maintained in a very narrow range. This is accomplished by a series of hormonal and physiologic responses. As a result, hypoglycemia is a rare occurrence in normal individuals. However, glucose counterregulatory responses are altered in patients with diabetes treated with insulin especially after repeated hypoglycemia or antecedent exercise.

Central nervous system: a conductor orchestrating metabolic regulations harmed by both hyperglycaemia and hypoglycaemia

Recent evidence suggests that the brain has a key role in the control of energy metabolism, body fat content and glucose metabolism. Neuronal systems, which regulate energy intake, energy expenditure, and endogenous glucose production, sense and respond to input from hormonal and nutrient-related signals that convey information regarding both body energy stores and current energy availability. In response to this input, adaptive changes occur that promote energy homeostasis and the maintenance of blood glucose levels in the normal range. Defects in this control system are implicated in the link between obesity and type 2 diabetes mellitus. The central nervous system may be considered the conductor of an orchestra involving many peripheral organs involved in these homeostatic processes. However, the brain is mainly a glucose-dependent organ, which can be damaged by both hypoglycaemia and hyperglycaemia. Hypoglycaemia unawareness is a major problem in clinical practice and is associated with an increased risk of coma. Stroke is another acute complication associated with diabetes mellitus, especially in elderly people, and the control of glucose level in this emergency situation remains challenging. The prognosis of stroke is worse in diabetic patients and both its prevention and management in at-risk patients should be improved. Finally, chronic diabetic encephalopathies, which may lead to cognitive dysfunction and even dementia, are also recognized. They may result from recurrent hypoglycaemia and/or from chronic hyperglycaemia leading to cerebral vascular damage. Functional imaging is of interest for exploring diabetes-associated cerebral abnormalities. Thus, the intimate relationship between the brain and diabetes is increasingly acknowledged in both research and clinical practice.

Sleep and the response to hypoglycaemia

Undetected nocturnal hypoglycaemia frequently occurs in patients with diabetes, having a negative influence on well-being, counterregulation against and awareness of subsequent hypoglycaemia, and even causing sudden death in some cases most likely by inducing cardiac arrhythmia. Sleep markedly weakens the neuroendocrine defence mechanism against hypoglycaemia by shifting the glycaemic threshold for counterregulatory activation to lower levels. While hypoglycaemia triggers awakening in healthy subjects, patients with type 1 diabetes frequently fail to awake in the presence of low plasma glucose levels. Little is known about the frequency of and responses to nocturnal hypoglycaemia in patients with type 2 diabetes. Unfortunately, effective strategies to prevent or even safely detect nocturnal hypoglycaemia are still lacking. Taken together, hypoglycaemia occurring during sleep presents a major, often neglected problem in the management of diabetic patients. Different aspects of this phenomenon such as responses to and consequences of nocturnal hypoglycaemia as well as strategies for its prevention are highlighted in this review.