Long-term intensive insulin therapy in IDDM: effects on HbA1c, risk for severe and mild hypoglycaemia, status of counterregulation and awareness of hypoglycaemia

Flexible insulin therapy improves metabolic control and decreases the risk of hypoglycemia in type 1 diabetic patients

Introduction

flexible insulin therapy (FIT) is considered as a crucial turning point in the management of type 1 diabetes. The purpose of this study was to evaluate the impact of this optimum therapeutic approach on improving metabolic control and decreasing hypoglycemic events in patients with type 1 diabetes.

Methods

thirty-seven type 1 diabetic patients were included in a five days training programme of FIT. They had an HbA1c between 7.5 and 10%. Those patients were enrolled in a flexible insulin program and we evaluate clinical and metabolic parameters (glycated haemoglobin (HbA1c), hypoglycemic events, body mass index (BMI) and the rate of blood glucose measurements) before the course of FIT and 3, 6 and 9 months after the course.

Results

over a 9 months period of the study, the frequency of mild hypoglycemia decreased from 11.7 to 1.7 episodes/3 months (p = 0.005). The baseline HbA1c value improved by 1% at 3 months with an increase of 0.2% at 6 months, which remained unchanged at 9 months (p = <0.0001). Patients who were poorly controlled (HbA1c ≥ 8%) improved their baseline HbA1c value from 9.2% to 8.0% (p = <0.0001).

Conclusion

the present study confirms that a structured training programme for FIT improves glycemic control and decreases hypoglycemic events in patients with type 1 diabetes and it can be adopted in countries with weak or intermediate income (e.g. Morocco), which allows those patients to take advantages of this therapeutic approach.

HbA1c may contribute to the development of non-alcoholic fatty liver disease even at normal-range levels

Previous clinical studies highlighted nonalcoholic fatty liver disease (NAFLD) as a hepatic facet of metabolic syndrome, which progresses toward Type 2 diabetes along with an elevation of HbA1c in the blood. Longitudinal observations were performed in a cohort of 2811 participants with no liver disease at inception. The rate of the conversion into NAFLD was 15.7% (440/2811), with a steady increase in prevalence observed in sub-cohorts with increasing HbA1c levels. Moreover, regression analysis indicated that HbA1c levels serve as the risk factors for NAFLD after multiple adjustments (odds ratio: 1.58, P-value < 0.004). When HbA1c-related molecular networks were investigated using natural language programming algorithms, multiple genetic/small molecular (SM) pathways were highlighted as connectors between the HbA1c levels and the development of NAFLD, including ones for nitric oxide, hypoxia and receptor for advanced glycation end products (RAGE). Our results suggest that increased levels of HbA1c may contribute to the progression of NAFLD either directly, by stimulating RAGE or indirectly, through the promotion of hypoxia and suppression of the release of NO. Further studies are needed to test the impact of HbA1c on the development of the chronic liver disease.

A Systematic Review of Cost-Effectiveness Models in Type 1 Diabetes Mellitus

BACKGROUND

Critiques of cost-effectiveness modelling in type 1 diabetes mellitus (T1DM) are scarce and are often undertaken in combination with type 2 diabetes mellitus (T2DM) models. However, T1DM is a separate disease, and it is therefore important to appraise modelling methods in T1DM.

OBJECTIVES

This review identified published economic models in T1DM and provided an overview of the characteristics and capabilities of available models, thus enabling a discussion of best-practice modelling approaches in T1DM.

METHODS

A systematic review of Embase(®), MEDLINE(®), MEDLINE(®) In-Process, and NHS EED was conducted to identify available models in T1DM. Key conferences and health technology assessment (HTA) websites were also reviewed. The characteristics of each model (e.g. model structure, simulation method, handling of uncertainty, incorporation of treatment effect, data for risk equations, and validation procedures, based on information in the primary publication) were extracted, with a focus on model capabilities.

RESULTS

We identified 13 unique models. Overall, the included studies varied greatly in scope as well as in the quality and quantity of information reported, but six of the models (Archimedes, CDM [Core Diabetes Model], CRC DES [Cardiff Research Consortium Discrete Event Simulation], DCCT [Diabetes Control and Complications Trial], Sheffield, and EAGLE [Economic Assessment of Glycaemic control and Long-term Effects of diabetes]) were the most rigorous and thoroughly reported. Most models were Markov based, and cohort and microsimulation methods were equally common. All of the more comprehensive models employed microsimulation methods. Model structure varied widely, with the more holistic models providing a comprehensive approach to microvascular and macrovascular events, as well as including adverse events. The majority of studies reported a lifetime horizon, used a payer perspective, and had the capability for sensitivity analysis.

CONCLUSIONS

Several models have been developed that provide useful insight into T1DM modelling. Based on a review of the models identified in this study, we identified a set of 'best in class' methods for the different technical aspects of T1DM modelling.

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.

Insulin therapy in type 1 diabetes

Although not curable, type 1 diabetes is eminently controllable. IIT, as guided by the results of landmark studies such as the DCCT, provides primary care providers with a blueprint for reducing the frequency of the devastating complications of diabetes that were all too common in the recent past. Considering the remarkable advances in contemporary therapy, including MDI and CSII, the likelihood of even greater future improvements in quality of life and survivability can be anticipated. Success requires patient engagement and education, an informed primary care provider, and an interdisciplinary team to maximize the benefits of insulin therapy and avoid the risks of hypoglycemia.

Optimizing the replacement of basal insulin in type 1 diabetes mellitus: no longer an elusive goal in the post-NPH era

In physiology, insulin is released continuously by the pancreas at a nearly constant rate between meals and in the fasting state (basal insulin secretion). The pivotal role of basal insulin is to restrain release of glucose from the liver and free fatty acids from adipose tissue, thus preventing hyperglycemia and ketosis. In type 1 diabetes mellitus (T1DM) (absolute insulin deficiency), the replacement of basal insulin is challenging because the currently available pharmacological preparations of long-acting insulin do not exactly reproduce the fine physiology of flat action profile of basal insulin of subjects without diabetes. NPH and NPH-based insulin mixtures no longer have a place in the treatment of T1DM because of their early peak effects and relatively short duration of action, which result into risk of nocturnal hypoglycemia and fasting hyperglycemia, respectively, after the evening injection. Only continuous subcutaneous (s.c.) insulin infusion (CSII) or long-acting analogs such as glargine (>24 h in duration, once a day) and detemir (<24 h in duration, once or more often twice a day) should be used as basal insulin in T1DM in combination with mealtime rapid-acting analogs. CSII and the long-acting analogs are nearly peakless and therefore reduce the risk for hypoglycemia (especially at night), blood glucose (BG) variability, and lower A1C with similar or less hypoglycemia. CSII is the "gold standard" of replacement of basal insulin because of better reproducibility of subcutaneous absorption of soluble insulin. Although CSII is not superior to multiple daily insulin injections in the general T1DM population, CSII might be indicated in subsets of T1DM (long-term T1DM with insulin "supersensitivity" and needs for low-dose insulin, some individuals with variable subcutaneous absorption of long-acting analogs) to minimize BG variability, reduce hypoglycemia, and benefit A1C.

Bioequivalence between two human insulin analogs in Chinese population: Glulisine and Lispro

Intensive insulin therapy for diabetic patients has been demonstrated as an appropriate treatment. Regular fast-acting insulin can hardly mimic the efficiency of endogenous meal-activated insulin secretion. Glulisine is a new rapid-acting insulin analog for mealtime insulin supplementation. We compared the pharmacokinetics and pharmacodynamics end points between the two rapid-acting insulin analogs Glulisine and Lispro. Twenty healthy adult males age ranging from 22 to 32 years were included in a randomized, open-label, cross contrast research. Two long duration hyperinsulinemic euglycemic clamp tests, one with Glulisine and the other with Lispro, were conducted on two separate days for all the participants. The two rapid-acting insulin analogs were administrated randomly to each participant. Glucose infusion rate (GIR) began to increase 20 min after injection in both Glulisine and Lispro groups. GIR increased sharply during the first 150 min and reached a peak at 6.23 ± 1.35 mg/(kg min) in the Glulisine group and 6.02 ± 1.27 mg/(kg min) in the Lispro group. It returned to the initial level at hour 5. The Area Under Curve (AUC(0-clamp end)) in Glulisine and Lispro groups were 1455.04 ± 381.88 mg/kg and 1356.25 ± 287.30 mg/kg (P > 0.05), respectively. However, AUC(0-1h) between the two groups showed significant difference, with Glulisine showed greater AUC(0-1h) in the first hour after injection. Other parameters showed no significant difference between the two groups. Insulin analogs Glulisine and Lispro were proved to have equivalent pharmacokinetic and pharmacodynamic parameters when administered to healthy Chinese adults, but with Glulisine showing greater AUC(0-1h) after injection.

Sustained efficacy of continuous subcutaneous insulin infusion in type 1 diabetes subjects with recurrent non-severe and severe hypoglycemia and hypoglycemia unawareness: a pilot study

BACKGROUND

This study evaluated the effect of CSII on hypoglycemia awareness and on glucose profile in type 1 diabetes (T1D) subjects with repeated non-severe or severe hypoglycemia (NS or SH, respectively).

METHODS

We included subjects (1) older than 18 years, (2) with T1D duration of >5 years, (3) on multiple doses of insulin, and (4) without micro- or macrovascular complications and more than four NS events per week (in the last 8 weeks) and more than two SH events (in the last 2 years). NS/SH episodes and hypoglycemia awareness were evaluated. A 72-h continuous glucose monitoring (CGM) was performed before continuous subcutaneous insulin infusion (CSII). A hypoglycemia-induced test was used to evaluate each patient's symptoms in euglycemia/hypoglycemia. Quality of life (QoL) was also evaluated. After 6, 12, and 24 months, all the subjects were reevaluated.

RESULTS

Twenty subjects were included (34.0 +/- 7.5 years old, 12 women, A1c 6.7 +/- 1.1%, 16.2 +/- 6.6 years of diabetes' duration). At baseline, 19 out of 20 subjects displayed hypoglycemia unawareness, which diminished significantly during the follow-up (3 out of 20). NH episodes per week diminished from 5.40 +/- 2.09 at baseline to 2.75 +/- 1.74 at the end of the follow-up (P < 0.001). SH episodes fell from 1.25 +/- 0.44 per subject-year to 0.05 +/- 0.22 after 24 months (P < 0.001). Hemoglobin A1c remained unaltered. With CGM, the percentage of values within 70-180 mg/dL increased (53.2 +/- 11.0% to 60.3 +/- 17.1%, P = 0.13), and the percentage of values <70 mg/dL decreased (13.7 +/- 9.4% to 9.1 +/- 5.2%, P = 0.07), after 24 months. Mean amplitude of glycemic excursions diminished after 24 months of CSII (136 +/- 28 mg/dL to 115 +/- 19 mg/dL; P < 0.02). An improvement in all the aspects of QoL was observed. The basal alteration in symptom response to an induced hypoglycemia improved after 24 months of initiating CSII leading to a response indistiguishable from that observed in a control group of subjects with T1D without repeated NH and SH.

CONCLUSIONS

CSII prevents hypoglycemic episodes, improves hypoglycemia awareness, and ameliorates glycemic profile in T1D subjects with repeated NS/SH. Its use is also associated with an improvement in diabetes QoL.

The effect of insulin glargine and nutritional model on metabolic control, quality of life and behavior in children and adolescents with type 1 diabetes mellitus

To determine the impact of glargine insulin therapy with different nutritional models on key parameters of diabetes including quality of life, behavior in children and adolescents with type 1 diabetes. Age, duration of diabetes, HbA1c, anthropometric data and episodes of severe hypoglycemia were taken from patients' charts. Diabetes quality of life scale and childhood behavior checklist questionnaires were given to each child at the start and at the end of 6 months. Mean age when starting on glargine insulin was 15.5 +/- 3. 8 years. Duration of diabetes was 7.1 +/- 4.3 years. About 14 of the patients chose to be in the carbohydrate counting group, whereas 24 of them continued with exchange meal plan as nutritional model. There was a reduction in HbA1c levels from 7.86 to 7.1% in the carbohydrate group and 8.8 to 8.0% in the exchange meal plan group. Total daily insulin dose did not change in both of the groups. BMI did not change in both of the groups. Diabetes-related worries decreased in carbohydrate group. No change was found in the behavior scores in both of the groups at the end of the study period. The use of glargine therapy among adolescents with type 1 diabetes was associated with improved overall glycemic control.

Management of diabetes-related hypoglycemia

Iatrogenic hypoglycemia is the main factor limiting aggressive and optimal diabetes management. Rather than being an inevitable consequence of optimal glycemic control, however, hypoglycemia is avoidable and generally straightforward to manage when it occurs. Professional caregivers, patients, and their families are often fearful of hypoglycemia, even though most episodes are minor and easily self-treated. Understanding the factors contributing to hypoglycemia risk and how to minimize its occurrence is an essential part of diabetes care. Building on the physiologic fundamentals presented in the accompanying review, the incidence, mortality/morbidity, clinical symptoms, severity classification, and psychosocial impact of hypoglycemia are described here. Appropriate selection and titration of therapeutic agents, including insulin analogs with more predictable time-action profiles than human insulin formulations, can reduce hypoglycemia risk. Patient education about hypoglycemia prevention, including symptom recognition and necessity of rapid treatment, behavioral modification, and the importance of frequent blood glucose monitoring should accompany all therapeutic interventions.

Advantage of premeal-injected insulin glulisine compared with regular human insulin in subjects with type 1 diabetes

OBJECTIVE

Insulin glulisine, a rapid-acting insulin analog, provides prandial insulin replacement. In this study, we compared postprandial blood glucose control after pre- and postmeal insulin glulisine with regular human insulin (RHI).

RESEARCH DESIGN AND METHODS

In a single-dose, randomized, four-way complete cross-over study, subjects received standardized, 15-min meals, covered by subcutaneous injections of either insulin glulisine (immediately premeal or 15 min postmeal; 0.15 unit/kg per injection) or RHI (30 min or immediately premeal; 0.15 unit/kg per injection). Twenty-one patients with type 1 diabetes (mean age 36.4 years; mean BMI 26.0 kg/m(2)) were enrolled; 20 patients completed the study. Postprandial baseline-subtracted blood glucose exposure, maximum excursion, maximum and minimum blood glucose concentrations, and time to the maximum excursion and minimum concentration were assessed, along with serum insulin concentrations.

RESULTS

Lower maximum blood glucose excursion (65 vs. 89 mg/dl), total blood glucose exposure within 2 h (279 vs. 334 mg . h/dl, maximum blood glucose concentration (180 vs. 209 mg/dl), and less time to maximum blood glucose excursion (48 vs. 70 min) were seen with immediately premeal insulin glulisine versus immediately premeal RHI. The maximum serum concentration of insulin glulisine was almost double that of RHI (82 vs. 45 microU/ml), achieved in approximately half the time (55 vs. 97 min). Conversely, insulin glulisine (15 min postmeal) versus RHI (immediately premeal) and RHI (30 min premeal) versus insulin glulisine (immediately premeal) resulted in comparable blood glucose control.

CONCLUSIONS

Insulin glulisine renders postprandial glucose disposal closer to physiologic requirements compared with RHI and enables appropriate timing of prandial insulin administration.

Multivariate models of health-related utility and the fear of hypoglycaemia in people with diabetes

AIM

The aim was to statistically model the degree of fear of hypoglycaemia experienced by people with diabetes, and then model the resulting change in health-related utility associated with differing severity and frequency of hypoglycaemia.

METHODS

The study used pooled data from two previous postal surveys among subjects with confirmed diabetes conducted in Cardiff, UK (n = 1305 responses). The fear of hypoglycaemia was characterised using the Hypoglycaemia Fear Survey (HFS [eight question worry sub-scale only]), and health-related utility using the EQ5D(index). The data were then analysed using univariate and multivariate analysis.

RESULTS

Following detailed preliminary analysis, a two-stage approach was used since fear was important when estimating the EQ5D(index). Fear was then modelled as a function of the severity and frequency of hypoglycaemia while controlling for other factors such as diabetes-related complications. Each severe hypoglycaemic event resulted in a change of 5.881 units on the HFS. One or more symptomatic hypoglycaemic events over the same period results in a corresponding change of 1.773 units on the HFS. A 1 unit increase on the HFS results in a 0.008 unit decrease on the EQ5D(index).

CONCLUSION

While controlling for other factors, the fear of hypoglycaemia was an important determinant of health-related utility. The magnitude of fear of hypoglycaemia was associated with the severity and frequency of hypoglycaemia. Hypoglycaemia was associated with a considerable decrement in health-related utility as a function of increased fear. Measures should be taken to minimise the severity and frequency of hypoglycaemia.

Impact of hypoglycaemia on quality of life and productivity in type 1 and type 2 diabetes

AIM

To characterise the impact of increasing severity and frequency of hypoglycaemia on utility, quality of life, primary care resource use and productivity (time away from normal activities) in people with both Type 1 and Type 2 diabetes.

METHODS

A postal survey was sent to 3200 people with diabetes. Self-reported episodes of mild, moderate, severe and nocturnal hypoglycaemia were quantified from a list of signs and symptoms. A number of instruments were used to explore the effect of frequency and severity of hypoglycaemia on quality of life and productivity.

RESULTS

There were 861 respondents for whom diabetes type was identifiable. Of these respondents, 629 (73%) experienced some form of hypoglycaemia, 516 (60%) non-exclusively experienced mild or moderate hypoglycaemia, 57 (7%) experienced severe hypoglycaemia and 191 (22%) experienced nocturnal hypoglycaemia. Quality of life and health-related utility decreased as the frequency and severity of hypoglycaemia increased. The use of primary care resources and lost productivity increased as the severity and frequency of hypoglycaemia increased. These associations were independent in multivariate analysis.

CONCLUSIONS

These findings suggest hypoglycaemia impacts heavily on the well-being, productivity and quality of life of people with diabetes, and that every effort should be made to minimise hypoglycaemia while aiming for good glycaemic control.

Flexible insulin therapy with glargine insulin improved glycemic control and reduced severe hypoglycemia among preschool-aged children with type 1 diabetes mellitus

BACKGROUND AND OBJECTIVES

Insulin replacement regimens now stress the importance of administering throughout the day insulin doses that are based on flexible food choices and focusing on improved metabolic control. A flexible multiple daily insulin (FMDI) regimen (premeal lispro plus bedtime glargine) results in lower hemoglobin A1c (HbA1c) levels and fewer hypoglycemic episodes than does a multiple daily insulin (MDI) regimen among school-aged children and adolescents with type 1 diabetes mellitus (DM). The purpose of this study was to determine the feasibility of FMDI therapy for a group of preschool-aged children with type 1 DM who were transitioned from MDI therapy (premeal lispro plus ultralente insulin twice per day), by comparing BMI, total daily insulin requirements, HbA1c levels, and episodes of severe hypoglycemia.

RESEARCH DESIGN AND METHODS

Data were collected over a 2-year period, during quarterly DM clinic visits, from 35 patients (17 female patients and 18 male patients, 4.8 +/- 1.0 years of age) who had received MDI insulin therapy for > or =1 year before being transitioned to a FMDI regimen.

RESULTS

Although there was no significant change in BMI with FMDI therapy (17.1 +/- 1.8 kg/m2 vs 17.0 +/- 1.7 kg/m2), 43% of patients (6 female subjects and 9 male subjects) were overweight (BMI of >85th percentile for age) both before and after treatment. The total daily insulin requirement (0.67 +/- 0.13 U/kg per day vs 0.78 +/- 0.14 U/kg per day) and bolus/basal insulin ratio (1.1 +/- 0.4 vs 1.9 +/- 0.6) were significantly increased and overall glycemic control was improved after transition to FMDI therapy (HbA1c levels: 8.8 +/- 0.9% vs 8.3 +/- 0.8%). However, HbA1c levels improved only among normal-weight subjects (9.0 +/- 1.0% vs 8.3 +/- 1.0%) and not among overweight subjects (8.7 +/- 0.7% vs 8.4 +/- 0.6%) after FMDI therapy. The overall rate of severe hypoglycemia was significantly decreased with the FMDI regimen (25.5 events per 100 patient-years vs 10.6 events per 100 patient-years) but again only for normal-weight children (29.7 events per 100 patient-years vs 7.4 events per 100 patient-years).

CONCLUSIONS

The use of FMDI therapy with glargine among preschool-aged children with type 1 DM was associated with improved overall glycemic control and decreased frequency of severe hypoglycemia. Although our study did not have a control group, these findings suggest that FMDI regimens may be a feasible therapeutic alternative to MDI treatment for preschool-aged children with type 1 DM. However, excess body weight status appeared to preclude a desirable therapeutic response in this group of patients.

Insulin therapy and hypoglycaemia: the size of the problem

BACKGROUND AND METHODS

Hypoglycaemia is a fact of life for people with diabetes mellitus. Mild, asymptomatic episodes occur once or twice a week in insulin-treated diabetic subjects. Asymptomatic hypoglycaemia, including nocturnal hypoglycaemia, occurs in about 25% of diabetic subjects treated with insulin therapy. Mild hypoglycaemia, if recurrent, induces unawareness of hypoglycaemia and impairs glucose counterregulation, which in turn predisposes to severe hypoglycaemia. Even brief hypoglycaemia can cause profound dysfunction of the brain. Prolonged, severe hypoglycaemia can cause permanent neurological sequels. In addition, it is possible that hypoglycaemia may accelerate the vascular complications of diabetes by increasing platelet aggregation and/or fibrinogen formation. Finally, hypoglycaemia may be fatal. Hypoglycaemia induced by insulin as treatment of type 1 diabetes mellitus (T1 DM) is not the consequence of diabetes, but invariably of the non-physiological replacement of insulin.

RESULTS

A number of studies have demonstrated that by moving from non-physiological to more physiological models of insulin therapy, most of the hypoglycaemia problems may be overcome, the percentage of glycated hemoglobin (A1c) decreased, and the quality of life improved. Interestingly, in T1 DM with hypoglycaemia unawareness, prevention of hypoglycaemia reverses not only unawareness but also improves glucose counterregulation, primarily the responses of adrenaline.

CONCLUSIONS

In order to best prevent hypoglycaemia, insulin should preferably be given as continuous subcutaneous infusion via a minipump (the 'golden standard') or multiple daily insulin administrations with insulin analogues (basal insulin glargine, meal insulin rapid-acting insulin analogues) in T1 DM.

Beneficial effects of continuous subcutaneous insulin infusion and flexible multiple daily insulin regimen using insulin glargine in type 1 diabetes

OBJECTIVE

The aim of this study was to evaluate the metabolic effects of continuous subcutaneous insulin infusion (CSII) with flexible multiple daily insulin (FMDI; premeal lispro + bedtime glargine) therapy as determined by glycosylated hemoglobin (HbA1c), body mass index (BMI), and hypoglycemic episodes in a group of patients who made the transition from multiple daily insulin (premeal lispro + bid ultralente) to either CSII or FMDI therapy.

METHODS

Data from 40 (27 female and 13 male) patients (10.1-17.8 years of age) who were on CSII and 40 age- and gender-matched (27 female and 13 male) patients (10.3-17.3 years of age) who were on FMDI were collected during regularly scheduled visits at a similar frequency over a 1-year period.

RESULTS

The total daily insulin dose did not change in CSII (0.97 +/- 0.24 vs 0.91 +/- 0.22 U/kg) and FMDI (0.98 +/- 0.21 vs 0.97 +/- 0.21 U/kg) patients, whereas the bolus:basal insulin ratio was significantly increased in both CSII (1.01 +/- 0.43 vs 1.32 +/- 0.52) and FMDI (1.07 +/- 0.0.41 vs 1.29 +/- 0.47) patients. The total cohort of CSII patients showed a decrease in HbA1c from 8.4 +/- 1.0% to 7.8 +/- 0.8%, whereas the FMDI cohort did not show a significant change in HbA1c (8.5 +/- 1.1% to 8.2 +/- 0.9%). However, 40% of the CSII group and 22.5% of the FMDI group showed > or =1.0% improvement in HbA1c. Also, a similar number of patients in CSII (52.5%; 8.0 +/- 1.1 to 7.2 +/- 0.5%) and FMDI (47.5%; 8.0 +/- 0.5% to 7.5 +/- 0.4%) maintained or achieved target HbA1c values <8.0%. The BMI increased significantly in the CSII group (21.6 +/- 3.2 vs 23.0 +/- 3.0 kg/m2) but did not change in the FMDI group (21.9 +/- 3.9 vs 22.6 +/- 3.8 kg/m2). There was a significant reduction in the rate of severe hypoglycemia (events/100 patient-years) in both cohorts: 20.6 to 8.2 in the CSII and 18.8 to 7.5 in the FMDI. Similarly, the rate of moderate hypoglycemia decreased in both CSII (68.3-35.4) and FMDI (56.3-30.4).

CONCLUSIONS

CSII therapy resulted in a significant improvement in HbA 1c in the entire group, whereas FMDI therapy improved HbA1c in only a subgroup of patients. However, almost half of the patients in each of the treatment groups maintained or achieved target glycemic control. Both CSII and FMDI treatment groups demonstrated a decreased rate of hypoglycemia without an abnormal increase in BMI. Although the design of this study does not allow direct comparison of the metabolic effects of CSII and FMDI therapies, both regimens seem to be superior to basal ultralente and lispro multiple daily insulin regimen and offer desirable therapeutic alternatives in pediatric diabetes care.

Modest contribution of psychosocial variables to hypoglycaemic awareness in Type 1 diabetes

OBJECTIVE

To assess relationships between hypoglycaemic awareness and diabetes-related, psychosocial and demographic characteristics.

METHOD

Ninety-eight type 1 diabetic patients completed questionnaires on somatic awareness (Somatic Awareness Questionnaire, SAQ), negative affectivity (Positive And Negative Affectivity Schedule, PANAS), symptom beliefs, bustle and variety of daily life. They then performed up to 70 measurements on a hand-held computer, during 4 to 6 weeks, at home. During every measurement, they rated the presence of 20 symptoms on a 0-6 scale, and estimated and measured their blood glucose level. The percentage of recognised hypoglycaemic episodes was calculated from these data, and used as a measure of hypoglycaemic awareness.

RESULTS

Hypoglycaemic awareness was negatively associated with disease duration and antecedent hypoglycaemia, and positively associated with the use of an insulin pump instead of injections, variety in the daily life, somatic awareness, sensitivity of the symptom beliefs and female gender. However, only 17% of the variance in hypoglycaemic awareness was explained.

CONCLUSIONS

Psychosocial variables contribute to hypoglycaemic awareness, to a moderate but statistically significant extent.

Glucose counterregulation in Type 2 diabetes mellitus

Glucose counterregulatory failure and hypoglycaemia unawareness frequently complicate treatment of Type 1 diabetes mellitus, especially when aiming for intensive metabolic control. Since tight metabolic control reduces microvascular long-term complications in Type 2 diabetes mellitus, the integrity of glucose counterregulation in Type 2 diabetic patients is important. Using a Medline search, we identified 12 studies in which counterregulatory responses to insulin-induced hypoglycaemia were compared between Type 2 diabetic patients and appropriate controls. A review of these studies showed that some patients with Type 2 diabetes mellitus develop mild counterregulatory dysfunction and reduced awareness of insulin-induced hypoglycaemia. Some studies suggested an association between counterregulatory impairment and intensity of metabolic control. We speculate that the relatively low frequency of (severe) hypoglycaemic events in Type 2 diabetes may explain why glucose counterregulation remains unaffected in most patients. We hypothesize that residual beta-cell reserve and insulin resistance provide protection against severe hypoglycaemia and limit impaired counterregulation. Diabet. Med. 18, 519-527 (2001)

Biological and behavioural determinants of the frequency of mild, biochemical hypoglycaemia in patients with Type 1 diabetes on multiple insulin injection therapy

BACKGROUND

Severe hypoglycaemic episodes are an important source of morbidity in people with Type 1 diabetes. The occurrence of severe hypoglycaemia is strongly related to the frequency of low blood glucose readings. The aim of this exploratory study was to identify determinants of the frequency of mild, biochemical hypoglycaemia in patients with Type 1 diabetes treated with multiple insulin injection therapy.

METHODS

We studied 31 patients with Type 1 diabetes in reasonable glycaemic control (HbA(1c)</=8.3%) during multiple injection therapy. The study had a prospective, observational design. We used standardised home blood glucose monitoring (HBGM) diaries to assess the frequency of hypoglycaemia (HBGM readings<3.5 mmol/L) over a period of 6 weeks. Potential determinants studied included biological factors, self-management factors (including weekly total physical activity and vigorous physical activity), psychological factors (including psychological distress) and mediating factors [average and standard deviation (SD) of the HBGM readings and self-reported hypoglycaemia awareness].

RESULTS

Determinants of mild hypoglycaemia frequency identified in univariate regression analyses were: SD and mean of HBGM (beta 0.6, p=0.001 and beta -0.6, p=0.001), diabetes duration (beta 0.5, p=0. 008) and self-reported hypoglycaemia unawareness (beta -0.5, p=0. 003). A trend was observed for performance of vigorous physical activities (beta 0.3, p=0.06) and external eating behaviour (beta -0. 3, p=0.1). These relations were confirmed in multivariate analyses.

CONCLUSIONS

Patients with Type 1 diabetes who have a high blood glucose variability and low average blood glucose concentration, diabetes of long duration, low body mass index, self-reported impaired awareness of hypoglycaemia and those participating in vigorous physical activities, specifically require interventions aimed at preventing hypoglycaemia.

Diabetic hypoglycaemia

Hypoglycaemia is a major factor preventing insulin-treated patients from achieving normoglycaemia. This reflects the inadequacy of current insulin treatment, which causes high insulin concentrations in the post-absorptive period. Physiological defences to hypoglycaemia include autonomic activation, which limits the fall in glucose level and causes symptoms, alerting patients to an impending episode. Many patients develop defective responses and hypoglycaemia unawareness after longstanding disease or with tight glycaemic control and are then prone to severe attacks. This may be the result of repeated hypoglycaemic episodes, which by altering cerebral glucose uptake, disturb the mechanisms that activate the central response to hypoglycaemia. Preventing further hypoglycaemia can partially reverse these defects and restore symptomatic awareness. Clinical hypoglycaemia has also been implicated in the 'dead in bed' syndrome and in chronic cognitive impairment. The problem of hypoglycaemia will eventually be solved by better insulin delivery and non-invasive glucose meters, but until then, more focused education may have a more substantial impact.

Long-term follow-up of insulin-dependent diabetes mellitus patients with recurrent episodes of severe hypoglycaemia

We conducted a long-term clinical follow-up of 20 insulin-treated diabetic patients with the problem of repeated severe hypoglycaemic events, identified during 1982-1984. Furthermore, we investigated the reproducibility of a standardized insulin-infusion test among eight of these patients and 10 insulin-dependent diabetes mellitus patients without the problem of severe hypoglycaemia. At start of the follow-up, the patients were characterized, which revealed that proposed risk factors for severe hypoglycaemia were very common and that at least one predisposing factor was present in all patients. No fatal episode of hypoglycaemia occurred in this group of patients during the follow-up. Emergency visits due to hypoglycaemia decreased during the follow-up from 1.05 year(-1) in 1982-1984 to 0.42 year(-1) in 1992-1994 (P=0.024). No association to HbAlc was seen (P=0.11). A correlation with the change to multiple insulin regimen was seen with a incidence of 1.27 year(-1) before the change to 0.47 year(-1) after (P=0.003). The glucose response to an insulin-infusion test appeared reproducible among the patients with recurrent attacks of severe hypoglycaemia.

Hypoglycemia unawareness in a patient with dumping syndrome: report of a case

We report the case of a 49-yr-old man affected by coma and hypoglycemia unawareness following repetitive hypoglycemic episodes due to dumping syndrome. The dumping syndrome, which was due to partial gastrectomy and vagotomy performed for recurrent peptic ulcer, was responsible for reactive hyperinsulinemia as demonstrated by an oral glucose tolerance test. While the glucose counterregulatory hormones were all normally sensitive to specific stimulation tests, insulin-induced hypoglycemia failed to induce an adequate counterregulatory response, causing no response in plasma norepinephrine, a slight and short increase in plasma cortisol, ACTH and glucagon and an insufficient increase in plasma epinephrine and GH. This case demonstrates that hypoglycemia unawareness has to be taken into account not only in patients affected by IDDM or insulinoma but also in any case of reactive hypoglycemia.

Diabetes teaching program improves glycemic control and preserves perception of hypoglycemia

Improvement of HbA1c is frequently accompanied by deteriorating awareness of hypoglycemia. We studied the effect of improved metabolic control on hypoglycemia perception in 33 type 1 diabetic patients during 3 months after an inpatient diabetes education program of 5 days. Patients were grouped according to the presence (H, n = 11) or the absence (N, n = 22) of a history of repeated severe hypoglycemia. To measure awareness of blood glucose (BG) and hypoglycemia, we calculated their accuracy of BG perception (error grid analysis) and sensitivity for BG levels < 3.9 mmol/l, respectively, during the first (I) and second (II) period of the 3 months using the method of BG estimation. HbA1c decreased from 8.0 +/- 0.3% before to 7.1 +/- 0.2% 3 months after the program (P < 0.001) with no difference between H and N. Neither accuracy of BG perception (40.6 +/- 3.8 (I) versus 43.6 +/- 4.1% (II), P = 0.25) nor sensitivity for low BG levels (49.1 +/- 4.2 (I) versus 54.9 +/- 4.9% (II), P = 0.12) changed significantly. Group H had a lower overall accuracy of BG estimation (P = 0.048) and a lower overall sensitivity for detecting BG levels < 3.9 mmol/l (P = 0.03) than group N. Group H was able to improve accuracy of BG estimation (H: 24.8 +/- 6.2 (I) versus 36.9 +/- 8.3% (II), P = 0.04) while group N was not (48.5 +/- 3.9 (I) versus 46.9 +/- 4.6% (II), P = 0.5). In conclusion, improvement of metabolic control after intensive diabetes education had no adverse effect on the perception of low BG levels. On the contrary, patients with a history of severe hypoglycemia improved their awareness of BG.

Hypoglycaemia during intensified insulin therapy of children and adolescents

Good metabolic control prevents or at least postpones late vascular complications, but several studies indicate that such good metabolic control cannot be reached without simultaneous increase in the incidence of severe hypoglycaemia. We have been able to reduce late complications through multiple insulin therapy adjusted on the basis of active self control combined with active psychosocial support and education. A prospective regular registration of all hypoglycaemic incidents in about 130 diabetic children and adolescents shows that in spite of reasonably good HbA1c values (mean and median 6.9%, corresponding to 7.9% with the DCCT method), we have less incidence of severe hypoglycaemia (13-17 per 100 patient years) than reported in other recent studies (20-25 per 100 patient years). We saw no correlation between HbA1c and severe hypoglycaemia, but most hypoglycaemia was caused by mistake or reasons not related to degree of metabolic control. Our conclusion is that there is no inevitable relation-ship between low HbA1c and hypoglycaemia. Instead hypoglycaemia should be prevented parallel to and in the same way as we try to reach good metabolic control.

Counterregulatory mechanisms to insulin-induced hypoglycemia in humans: relevance to the problem of intensive treatment of IDDM

Hypoglycemia unawareness is a condition of decreased/absent perception of specific symptoms which normally inform the subject that plasma glucose is decreasing to dangerous levels resulting in neuroglycopenia. This syndrome is frequent in IDDM. In the absence of warning symptoms, IDDM patients cannot take any measure (e.g. eating) to prevent severe neuroglycopenia (unconsciousness). Because hypoglycemia unawareness is associated with impaired glucose counterregulation, especially reduced adrenaline responses, hypoglycemia unawareness is a risky condition for severe hypoglycemia. A number of studies in animals and humans indicate that hypoglycemia unawareness is largely, if not fully, secondary to recurrent or chronic hypoglycemia. Meticulous prevention of hypoglycemia in IDDM largely recovers the symptoms of hypoglycemia and the responses of adrenaline. It is important that diabetologists and IDDM patients are familiar with the syndrome of hypoglycemia unawareness and learn how to prevent/treat it in programs of intensive therapy. Intensive therapy aiming strictly at normoglycemia may increase the frequency of hypoglycemia and hypoglycemia unawareness. On the other hand, if intensive therapy is combined with a program of prevention of hypoglycemia, the percentage of HbA1c can be maintained long-term below 7.0% (i.e. below values risky for onset/progression of complications), and at the same time the frequency of hypoglycemia is very low. Under these conditions, IDDM patients maintain the awareness of warning symptoms and adrenaline response to hypoglycemia, a vital back-up system for the safety of intensive therapy of IDDM.