Physiological insulin replacement in type 1 diabetes mellitus

Ovarian functions and polycystic ovary syndrome in adult women with type 1 diabetes mellitus in a Turkish population

PURPOSE

The effect of gonadotropin-releasing hormone agonist (GnRHa) stimulation has not been studied in adult women with type 1 diabetes mellitus (DM). We investigated the baseline and stimulated hormone levels after GnRHa and the frequency and relationship between polycystic ovary syndrome (PCOS) and type 1 DM in adult women with type 1 DM.

METHODS

We included 55 adult women (age, 17-35 years) with type 1 DM and 15 healthy women (age, 20-29 years). Hormones including total testosterone, androstenedione, dehydroepiandrosterone sulphate (DHEAS), follicle-stimulating hormone (FSH), luteinising hormone (LH), estradiol, prolactin, and thyroid-stimulating hormone were measured in the early follicular phase of the menstrual cycle. All participants underwent GnRHa stimulation test, and FSH, LH, estradiol and 17-OHP response levels were measured every 6 h for 24 h. PCOS was diagnosed according to ESHRE/ASRM (Rotterdam) criteria.

RESULTS

Between patients with type 1 DM and healthy controls, no significant differences were noted in mean age and body mass index (BMI) as well as baseline and stimulated hormone levels after buserelin stimulation, except for baseline serum 17-OHP levels, which was higher in patients with type 1 DM. Polycystic ovary morphology (PCOM) was detected in 14 (25%) patients, clinical hyperandrogenism in 16 (29%), hyperandrogenemia in 25 (45%), anovulatory cycle in 72%, and PCOS in 20 (36%).

CONCLUSION

All parameters representing androgen excess disorders, except 17-OHP level, of both groups were similar, and frequencies of PCOS and anovulatory cycle in adult women with type 1 DM were 36% and 72%, respectively.

Living with Insulin: The story of insulin from people with diabetes

The history of insulin is rightly considered one of the most beautiful stories in medicine which goes even further than the extraordinary result of tens of millions of lives saved. Without a doubt, it constitutes a major achievement for medical science which, especially in the last 50 years, has led to an impressive acceleration in the succession of new treatment opportunities. We are going to describe the history of insulin therapy, the history we lived from two different angles as people living with type 1 diabetes, and obviously also as diabetologists, but as diabetologists with diabetes. Without a doubt, insulin and his story constitutes a major achievement for medical science which has led to an impressive acceleration in the succession of new treatment opportunities. Care opportunities that have not only allowed fundamental improvements in outcomes, but have also and above all impacted the quality of life of people with diabetes. Summarizing one hundred years of insulin is no simple endeavor. In our view, it would be easier, and probably more befitting, to focus on the last 50 years, namely the period we have lived closely and personally together with insulin. More to the point, these last 50 years have witnessed a dramatic acceleration of research and innovation. In our opinion, it is precisely the innovations in insulin therapy introduced from the last decades that fully justify the description of events in this incredible period as "the miracle of insulin". We'll describe how the most important innovations introduced in the last decades had impact on what we have nowadays, as patients and diabetologits: today, we can finally adapt insulin therapy to the patient's life or lifestyle, reversing what was the perception of patients until 20 years, when insulin was considered, by the most, as an obstacle, which seemed insurmountable to some, to a free and unconstrained life.

A model-based approach to investigating the relationship between glucose-insulin dynamics and dapagliflozin treatment effect in patients with type 2 diabetes

AIMS

To develop a quantitative systems pharmacology model to describe the effect of dapagliflozin (a sodium-glucose co-transporter-2 [SGLT2] inhibitor) on glucose-insulin dynamics in type 2 diabetes mellitus (T2DM) patients, and to identify key determinants of treatment-mediated glycated haemoglobin (HbA1c) reduction.

MATERIALS AND METHODS

Glycaemic control during dapagliflozin treatment was mechanistically characterized by integrating components representing dapagliflozin pharmacokinetics (PK), glucose-insulin homeostasis, renal glucose reabsorption, and HbA1c formation. The model was developed using PK variables, glucose, plasma insulin, and urinary glucose excretion (UGE) from a phase IIa dapagliflozin trial in patients with T2DM (NCT00162305). The model was used to predict dapagliflozin-induced HbA1c reduction; model predictions were compared to actual data from phase III trials (NCT00528879, NCT00683878, NCT00680745 and NCT00673231).

RESULTS

The integrated glucose-insulin-dapagliflozin model successfully described plasma glucose and insulin levels, as well as UGE in response to oral glucose tolerance tests and meal intake. HbA1c reduction was also well predicted. The results show that dapagliflozin-mediated glycaemic control is anticorrelated to steady-state insulin concentration and insulin sensitivity.

CONCLUSIONS

The developed model framework is the first to integrate SGLT2 inhibitor mechanism of action with both short-term glucose-insulin dynamics and long-term glucose control (HbA1c). The results suggest that dapagliflozin treatment is beneficial in patients with inadequate glycaemic control from insulin alone and this benefit increases as insulin control diminishes.

Advances in the management of diabetes: new devices for type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune condition that affects a significant number of people worldwide, with higher prevalence in white European populations. The condition is responsible for a high burden of microvascular complications, especially when poorly controlled. The condition is also burdensome on the patient and has major psychosocial and occupational impacts. It requires lifelong frequent blood glucose monitoring and regular insulin injections. Important technological advances in the management of T1D have occurred in recent years. These include the advent of new glucose testing devices using interstitial glucose, and new insulin delivery devices. These technologies may improve quality of life, and glucose management in this condition. This review aims to outline the current advances in the management of T1D for the general physician, with a particular focus on new technologies.

Quality of care of patients with type 1 diabetes: population-based results in a French region

AIM

Although the incidence of type 1 diabetes (T1D) has been increasing, little is known of its quality of care. Thus, our survey was designed to retrospectively evaluate this issue in French patients.

METHODS

Patients with T1D living in northeastern France were identified thanks to the healthcare system (CPAM) database, and the resulting list reviewed by local diabetes specialists. All of the listed patients and their primary physicians were asked to fill in a questionnaire including clinical data, laboratory results and follow-up habits. The 'optimized results' included CPAM-based results plus any specialized care provided during hospitalizations in diabetes and non-diabetes units, according to questionnaire data.

RESULTS

A total of 227 individuals, for whom CPAM data were available, were identified as having T1D. From these patients, 174 questionnaires were answered, and optimized results (having both CPAM data and a completely filled-in questionnaire) were available for 149 patients. Of the 169 patients who responded, 71.3% reported at least a yearly visit with a diabetologist. This number reached 77.9% when optimized results were considered. Patients who received specialized care were younger, underwent HbA(1c) tests more often and were more frequently on optimal treatment; however, there was no difference in HbA(1c) values or in the prevalence of complications. Eye examinations and kidney tests had been performed at least once over the 2-year period in more than 87% of the patients, whereas around 30%, 21% and 23% had an eye exam, creatinine test and urinary albumin excretion measurement, respectively, only once over the same time period.

CONCLUSION

This is the first large-scale study of the quality of care in patients with T1DM in France, and it could serve as a preliminary survey for a national study. Although the follow-up was better than previously reported, there is still considerable room for improvement.

Female reproduction and type 1 diabetes: from mechanisms to clinical findings

BACKGROUND

The functional reproductive alterations seen in women with type 1 diabetes (T1D) have changed as therapy has improved. Historically, patients with T1D and insufficient metabolic control exhibited a high prevalence of amenorrhea, hypogonadism and infertility. This paper reviews the impact of diabetes on the reproductive axis of female T1D patients treated with modern insulin therapy, with special attention to the mechanisms by which diabetes disrupts hypothalamic-pituitary-ovarian function, as documented mainly by animal model studies.

METHODS

A comprehensive MEDLINE search of articles published from 1966 to 2012 was performed. Animal model studies on experimental diabetes and human studies on T1D were examined and cross-referenced with terms that referred to different aspects of the gonadotropic axis, gonadotrophins and gonadal steroids.

RESULTS

Recent studies have shown that women with T1D still display delayed puberty and menarche, menstrual irregularities (especially oligomenorrhoea), mild hyperandrogenism, polycystic ovarian syndrome, fewer live born children and possibly earlier menopause. Animal models have helped us to decipher the underlying basis of these conditions and have highlighted the variable contributions of defective leptin, insulin and kisspeptin signalling to the mechanisms of perturbed reproduction in T1D.

CONCLUSIONS

Despite improvements in insulin therapy, T1D patients still suffer many reproductive problems that warrant specific diagnoses and therapeutic management. Similar to other states of metabolic stress, T1D represents a challenge to the correct functioning of the reproductive axis.

Contraception, and pregnancy in adolescents with type 1 diabetes: a review

Adolescence is a critical period for girls with type 1 diabetes mellitus (T1D). Reproductive issues, such as menstrual abnormalities, risk of an unplanned pregnancy, and contraception, should be addressed during this phase of life. This paper reviews several reproductive issues that are important in the care of adolescents, including pubertal development, menstrual abnormalities, ovulatory function, reproductive problems, the effects of hyperglycemia, contraception, and treatment of an unplanned pregnancy. A review of the literature was conducted. A MEDLINE search January 1966 to March 2011 was performed using the following MESH terms: puberty, menarche, ovary, polycystic ovary syndrome, menstruation, contraception, contraception-barrier, contraceptives-oral-hormonal, sex education, family planning services, and pregnancy in adolescence. This literature search was cross-referenced with an additional search on diabetes mellitus-type 1, diabetes complications, and pregnancy in diabetes. All published studies were searched regardless of the language of origin. Bibliographies were reviewed to extract additional relevant sources.

Mid- and high-ratio premix insulin analogues: potential treatment options for patients with type 2 diabetes in need of greater postprandial blood glucose control

Some patients with type 2 diabetes continue to have high postprandial blood glucose levels on twice-daily regimens of 'low-ratio' premix insulin formulations (up to 30% rapid-acting, with 70% protracted insulin). These patients require intensified insulin therapy, which can be provided by a twice- or thrice-daily regimen of mid-ratio (50% rapid-acting and 50% protaminated intermediate-acting insulin - human or analogue) or high-ratio (70% rapid-acting and 30% protaminated insulin - analogue only) premix insulin. Alternatively, a third daily injection of low-ratio premix insulin can be added to the regimen, with the option of incorporating one or more injections of mid- or high-ratio premix as required, and as an alternative to basal-bolus therapy. How these mid- and high-ratio formulations differ from the low-ratio premix insulins is reviewed here, with the aim of identifying the role of these formulations in diabetes management. Glucose clamp studies have shown that premix analogues give serum insulin levels proportional to their percentage of rapid-acting uncomplexed insulin: the higher the proportion, the greater the maximum level reached. Other pharmacokinetic parameters were not always significantly different between the mid- and high-ratio formulations. In clinical trials, postprandial plasma glucose and glycated haemoglobin A1c (HbA(1c)) levels were significantly reduced with thrice-daily mid- /high-ratio premix analogue when compared with twice-daily low-ratio biphasic human insulin (BHI) 30/70 or once-daily insulin glargine. Moreover, glycaemic control with mid-/high-ratio premix analogue was found to be similar to that with a basal-bolus therapy. Mid- and high-ratio premix regimens are generally well tolerated. The frequency of minor hypoglycaemia was reportedly higher with mid- /high-ratio premix analogues than with BHI 30, but nocturnal hypoglycaemia was less frequent. Although there is little evidence that clinical outcomes with mid-ratio premix analogues are different from those with high-ratio, they are useful additions to the low-ratio formulations for the management of diabetes, and addressing postprandial hyperglycaemia in particular.

Biphasic insulin aspart 30/70 (BIAsp 30) in the treatment of type 1 and type 2 diabetes

The pharmacological advantages of the rapid-acting analog, insulin aspart, over human insulin have contributed to the widespread prescription of the premix, biphasic insulin aspart 30/70 (BIAsp 30), in type 1 (T1DM) and type 2 diabetes (T2DM). This article reviews the available literature on the pharmacology, efficacy and safety of BIAsp 30 in T1DM and T2DM from an online search of the PubMed database. Following injection, BIAsp 30 reaches higher plasma insulin levels more quickly than human premix or basal insulin, giving effective reduction of postprandial hyperglycemia. In T1DM patients, randomized controlled trials (RCTs) have shown that HbA(1c) reduction is similar, but postprandial glycemic control is better, with BIAsp 30 than with human insulin regimens. In T2DM patients, lowering of HbA(1c) and postprandial hyperglycemia with BIAsp 30 compare favorably with optimized oral antidiabetes drug treatment, insulin glargine, and, in obese patients, human premix. An increase in minor hypoglycemia with BIAsp 30 relative to basal insulin has been reported in T2DM patients, but major and nocturnal hypoglycemia rates are generally low. Findings from RCTs in T2DM patients are supported by large observational studies. In summary, BIAsp 30 once to three times daily represents a simple and effective tool for the modern management of diabetes.

The pharmacokinetic and pharmacodynamic properties of different formulations of biphasic insulin aspart: a randomized, glucose clamp, crossover study

BACKGROUND

Type 2 diabetes patients on premixed insulin are commonly prescribed biphasic insulin with low prandial insulin content, such as biphasic insulin aspart (BIAsp) 30, comprising 30% insulin aspart (IAsp). The new formulations BIAsp 50 and BIAsp 70 contain 50% and 70% soluble IAsp, respectively. We compared the pharmacodynamics (PD) and pharmacokinetics (PK) of BIAsp 30, 50, and 70 and IAsp in a glucose clamp trial.

METHODS

In this randomized, double-blind, crossover study at a clinical research institute, 32 type 1 diabetes patients on basal-bolus therapy each underwent four glucose clamps (clamp level 5 mmol/L, duration 28 h post-dosing [12 h for IAsp]) and received a single dose of 0.4 U/kg BIAsp 30, 50, or 70 and IAsp. Main PD/PK outcome parameters measured were early- and late-phase glucose disposal (area under the curve of glucose infusion rate [AUC(GIR)]), nonesterified fatty acid concentrations, and IAsp concentrations.

RESULTS

With increasing proportions of soluble IAsp, the insulin formulations showed significantly higher early metabolic activity (ratio of AUC(GIR) 0-6 h: BIAsp 50/BIAsp 30 = 1.28 [P < 0.001], BIAsp 70/BIAsp 50 = 1.18 [P < 0.001), IAsp/BIAsp 70 = 1.15 [P < 0.01]) and lower late metabolic activity (ratio of AUC(GIR) 12-28 h: BIAsp 50/BIAsp 30 = 0.17 [P < 0.01], BIAsp 70/BIAsp 50 = 0.21 [P < 0.05]). Likewise, early IAsp levels were significantly greater and late PK concentrations were significantly lower with increasing proportion of soluble IAsp.

CONCLUSIONS

There are significant differences between the early and late PD and PK effects among BIAsp 30, 50, and 70 and IAsp that should allow tailored treatment with the convenience of prandial and basal insulin in each injection.

Lispro insulin-induced lipoatrophy: a new case

Lipoatrophy (LA) is a rare complication of insulin treatment in type 1 diabetes mellitus. The pathogenesis of insulin-induced LA is still unknown. Many theories suggest immunological reactions. We report a 4-yr-old Saudi girl with LA probably induced by lispro insulin. A review of the literature on the clinical features, pathophysiology, differential diagnosis, and treatment is briefly discussed.

Premixed insulin treatment for type 2 diabetes: analogue or human?

The progressive nature of type 2 diabetes makes insulin initiation a necessary therapeutic step for many patients. Premixed insulin formulations containing both basal and prandial insulin (so called biphasic insulin) are often prescribed because they are superior to long- or intermediate-acting insulin in obtaining good metabolic control. In addition, they are considered as an attractive alternative to classical basal-bolus therapy as fewer daily injections are required. Premixed insulin formulations include conventional (e.g. biphasic human insulin 70/30, or 30/70 in European countries, BHI 30) and newer premixed human analogues (e.g. biphasic insulin aspart 70/30, or 30/70 in Europe, BIAsp 30; insulin lispro mix 75/25-Mix 75/25, or Mix 25/75 in Europe). Like conventional premixed human insulin, premixed insulin analogues contain a fixed proportion of soluble, rapid-acting insulin analogue, with protaminated analogue comprising the remainder. Unlike conventional premixes, analogue premixes have more physiological pharmacokinetic and therapeutically more desirable pharmacodynamic profiles than premixed human insulin. Consequently, postprandial glycaemic control is better with premixed insulin analogues than with premixed human insulin. In nontreat-to-target registration trials, the lowering of haemoglobin A(1c) with premixed insulin analogues was not inferior to that seen with premixed human insulin. Minor hypoglycaemia was similar for premixed analogue and premixed human insulins, while major hypoglycaemia appears to be rare with either formulation. The occurrence of adverse events, other than hypoglycaemia, was also similar between various premix insulins. The premixed insulin analogues, BIAsp 30 and Mix 75/25, like the fast-acting analogues from which they are derived, also allow flexible injection timing, relative to meal timing, thus improving adherence, compliance and quality of life compared with premixed human insulin. Overall, the evidence suggests that premixed insulin analogues are cost effective and have useful advantages over premixed human insulin for the treatment of type 2 diabetes.

Basal insulin supplementation in Type 1 diabetic children: a long-term comparative observational study between continuous subcutaneous insulin infusion and glargine insulin

No long-term data are available on the efficacy of glargine insulin in comparison with continuous sc insulin infusion (CSII) in children and adolescents affected by Type 1 diabetes (T1D). Our aim was to compare the 2-yr efficacy of the 2 insulin approaches, in order to know how to best supply basal insulin in these patients. Thirty-six 9 to 18-yr-old consecutive children with at least 3 yr previous T1D diagnosis were enrolled. As part of routine clinical care, the patients consecutively changed their previous insulin scheme (isophane insulin at bedtime and human regular insulin at meals) and were randomly selected in order to receive either multiple daily injections (MDI) treatment with once-daily glargine and human regular insulin at meals, or CSII with aspart or lispro insulin. Both groups showed a significant decrease in glycosylated hemoglobin (HbA1c) values during the 1st year of therapy, though only in the CSII treated children was the decrease also observed during the 2nd year. The overall insulin requirement significantly decreased only in the CSII group and exclusively during the 1st year, while no significant differences were observed concerning body mass index SD score, severe hypoglycemic episodes and basal insulin supplementation. The work illustrates the first long-term study comparing the efficacy of CSII to MDI using glargine as basal insulin in children. Only with CSII were better HbA1c values obtained for prolonged periods of time, so that CSII might be considered the gold standard of intensive insulin therapy also for long-term follow-ups.

Posição de consenso da Sociedade Brasileira de Diabetes: insulinoterapia intensiva e terapêutica com bombas de insulina

Este artigo relata a posição de consenso da Sociedade Brasileira de Diabetes sobre a insulinoterapia intensiva e a terapêutica com bombas de infusão de insulina, obtida durante simpósio de atualização realizado especificamente para esta finalidade, em 2003. Estas modalidades de tratamento do diabetes são aqui conceituadas, seus fundamentos são colocados, e os aspectos práticos de indicações, exeqüibilidade, limites, técnicas e relação custo-benefício são analisados. As técnicas envolvem os esquemas de auto-monitorização glicêmica sugeridos e as doses, tipos, formas de administração da insulina e fatores de cálculo utilizados em cada modalidade de tratamento intensivo, tanto no DM1 quanto no DM2. O papel da SBD na implementação dos tratamentos intensivos do diabetes e a atuação dos vários profissionais envolvidos são discutidos e comentados. Conclui-se com as respostas de consenso a questões orientadoras do tema, formuladas na apresentação do simpósio.

How to achieve a predictable basal insulin?

The development of insulin analogues over the last two decades have aimed at optimising the pharmacokinetic profile of subcutaneously injected insulin for therapeutic use in diabetes mellitus. Rapid acting analogues were successfully engineered and marketed in the late 1990's. In engineering long-acting analogues it has been a particular challenge to obtain action profiles that would be predictable from day to day in the same person. The most recent approach has been to acylate the insulin molecule with a fatty acid which provides the insulin molecule with a specific affinity for albumin. The first clinically available agent of this type is insulin detemir. Pharmacological studies have shown that reversible albumin binding will protract absorption following subcutaneous injection but still allow the insulin molecule to be recognised by the insulin receptor following dissociation from the carrier protein. Moreover, the molecular features of insulin detemir are attractive in that the molecule can be formulated as a neutral aqueous solution and does not precipitate after injection. Together with an important buffering mechanism effected by plasma albumin binding, this explains a highly significant reduction of within-subject variability of pharmacodynamic response observed in repeat isoglycaemic clamp studies where insulin detemir was compared to other basal insulin products. No safety considerations have been identified in using albumin as an insulin carrier to protract and buffer insulin action. In assessing the clinical attractiveness of insulin analogues, it is furthermore critically important to consider how the molecular modifications impact efficacy and safety. A number of pharmacological studies have shown that insulin detemir overall retains the molecular pharmacological properties of native human insulin, including a physiological balance between metabolic and mitogenic potencies. Taken together, insulin detemir provides an attractive novel approach for predictive basal insulin delivery to people with diabetes.

An observational study comparing continuous subcutaneous insulin infusion (CSII) and insulin glargine in children with type 1 diabetes

OBJECTIVE

The advantages of continuous subcutaneous insulin infusion (CSII) or insulin glargine have been demonstrated both in adult and paediatric diabetic patients; however, as no data comparing these two approaches during childhood are available, we have examined the efficacy of these two intensive approaches.

RESEARCH DESIGN AND METHODS

We retrospectively evaluated data from 36 diabetic children, who had changed their previous insulin regimen [with isophane insulin (NPH) at bedtime] because of HbA1c levels >8.0%. Twenty patients underwent CSII, while the other 16 (significantly younger for age) started insulin glargine at bedtime.

RESULTS

At 6 and 12 months, CSII-treated patients showed a significant reduction in HbA1c values from 8.5 +/- 1.8 to 7.4 +/- 1.1% and to 7.6 +/- 1.2%, respectively. The insulin requirement significantly decreased from 0.93 +/- 0.2 IU/kg to 0.73 +/- 0.2 IU/kg of body weight and to 0.74 +/- 0.15 IU/kg of body weight, respectively, while no significant differences were observed for BMI SDS, fructosamine and severe hypoglycaemic events. The patients treated with glargine showed a small decline in HbA1c values from 8.9 +/- 1.7 to 8.3 +/- 0.9% (not significant) in the first 6 months of treatment and to 8.2 +/- 0.9% after 12 months.

CONCLUSION

The basal insulin supplementation can be supplied effectively in children with type 1 diabetes by either CSII or insulin glargine. As previously reported for adults, it is confirmed that CSII is the best current intensive approach aimed to the improvement of glycaemic control.

Insulin aspart improves meal time glycaemic control in patients with Type 2 diabetes: a randomized, stratified, double-blind and cross-over trial

AIMS

This randomized, multi-centre, double-blind, stratified, two period, cross-over trial was undertaken to assess the pharmacokinetics and pharmacodynamics of insulin aspart injected immediately before compared with regular human insulin injected 30 min before a Mediterranean-style meal in 37 (23 M, 14 F) patients with Type 2 diabetes.

METHODS

Insulin aspart or regular human insulin was given subcutaneously (0.15 U/kg) in random sequence, using a double-dummy technique (at one visit: human regular insulin at t=-30 min and placebo at t=0; at the other visit: placebo at t=-30 min and aspart insulin at t=0). Serum glucose and insulin concentrations (15 points) were measured after each meal for 240 min.

RESULTS

Post-prandial glycaemic excursions were 20% lower with insulin aspart (IAsp) compared with regular human insulin (HI) treatment [ratio (Iasp/HI)=0.80, CI=(0.66-0.98), P=0.034]. The maximum serum glucose (SG) concentration was similar for the two treatments (P=NS). The (median) time to maximum SG was 25 min shorter for IAsp compared with HI (P=0.048). Maximum serum insulin concentration was higher after IAsp compared with HI (P=0.023) as well as the area under the 4-h serum insulin curve (P=0.006). Furthermore, the time to maximum serum insulin concentration was 27 min shorter after IAsp (P=0.039), even though IAsp was injected 30 min after HI. No adverse events occurred during the trial.

CONCLUSIONS

In patients with Type 2 diabetes a more favourable insulin profile and a better glycaemic control were found with IAsp injected immediately before compared with HI injected 30 min before a Mediterranean-style meal.

Engineering predictability and protraction in a basal insulin analogue: the pharmacology of insulin detemir

The suboptimal nature of the absorption profiles of human insulin formulations following subcutaneous administration has prompted the development of insulin analogues better suited for therapeutic use in diabetes mellitus. A particular challenge has been to engineer long-acting agents that do not produce unduly variable responses from one injection to another. One recent approach that has met with success has been to acylate, the insulin molecule with a fatty acid, thereby enabling reversible albumin binding. The first clinically available agent of this type is insulin detemir. Pharmacological studies have established that this principle is effective in prolonging action, primarily by retarding absorption. The solubility of insulin detemir in the vial and after injection and an important buffering mechanism effected by plasma albumin binding explain a significant decrease in within-subject variability of pharmacodynamic response observed in repeat isoglycaemic clamp studies where insulin detemir was compared to other basal insulin products. Owing to the extremely high ratio of albumin-binding sites to insulin detemir molecules at therapeutic concentrations, no safety considerations have been identified pertaining to albumin binding. The insulin detemir molecule retains the molecular pharmacological properties of native human insulin, including a physiological balance between metabolic and mitogenic potencies. Thus, insulin detemir offers the promise of an improved tolerability:efficacy ratio in the clinical setting.

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.

Efficacy Comparison between preprandial and postprandial insulin aspart administration with dose adjustment for unpredictable meal size

BACKGROUND

Patients with type 1 diabetes mellitus (DM) may encounter situations in which meal size and content is unpredictable. In theory, postprandial injection of rapid-acting insulin analogues could prove more effective in achieving glucose control at such times because this treatment strategy could allow adjustment of insulin dose for the actual size of the meal consumed rather than being based on an estimate of what will be consumed.

OBJECTIVE

This study compared the postprandial glycemic control achieved with meal-related insulin aspart injected immediately before a meal with that injected immediately after a meal.

METHODS

This randomized, crossover study was conducted at Sansum Diabetes Research Institute, Santa Barbara, California. Adult patients with type 1 DM were enrolled. At study visit 1, patients were randomly assigned to inject insulin aspart 0 to 5 minutes before the start of the meal or immediately after the meal. The timing of injection relative to the meal was reversed at study visit 2. The meal-related dose was calculated based on the anticipated caloric and carbohydrate intake (preprandial injection) or actual calories and carbohydrates ingested (postprandial injection). Postprandial blood glucose concentrations were evaluated as markers of efficacy of postprandial aspart administration.

RESULTS

Twenty patients were enrolled in the study (mean [SE] duration of DM, 22.5 [3.2] years; mean [SE] body mass index, 26.2 [1.0] kg/M2; age range, 22-82 years); 19 completed it. Total glucose AUC during the meal test was 22% less when insulin aspart was injected immediately before the study meal (mean [SE], 23,014 [1832] mg/dL.min) than when injected immediately after the meal (mean [SE], 29,535 [2243] mg/dL.min) (P < 0.001), but baseline-adjusted AUC was similar. Maximum mean (SD) glucose concentrations in the postprandial period were <180 mg/dL, the current DM treatment goals specified by the American Diabetes Association (149.0 [9.9] mg/dL and 102.0 [9.2] mg/dL, following postprandial insulin aspart injection and preprandial injection, respectively; P < 0.001). There was variation in the number of calories consumed, but patients consumed a similar number of calories in the 2 treatment regimens. The frequency of postprandial hypoglycemia was comparable. Adjustment of postprandial insulin aspart dose for the actual meal size consumed maintained postprandial glucose concentrations within currently recommended treatment guidelines.

CONCLUSIONS

Preprandial insulin aspart injection produced a better glucose profile and is preferred when conditions permit. However, both preprandial and postprandial insulin aspart administration achieved postprandial glucose concentrations within currently recommended treatment guidelines.

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.

Self-management support for insulin therapy in type 2 diabetes

PURPOSE

The purpose of this article is to describe the self-management support that can be provided by diabetes educators for type 2 diabetes patients who are transitioning from therapy with oral hypoglycemic agents to insulin.

METHODS

The role of the diabetes educator in patient education and self-management support during all aspects of insulin therapy is discussed. Phases during which support may be especially important include the decision-making process, initiation, and maintenance.

RESULTS

Although some patients make the decision fairly easily, the introduction of insulin therapy is likely to raise many issues and questions for many type 2 diabetes patients. The more reluctant patients may experience psychological insulin resistance, a syndrome where insulin therapy is viewed as a threat or failure, which can affect health professionals as well. The diabetes educator can provide support and approaches to help diminish this resistance and make the transition to insulin therapy easier and more effective for patients with type 2 diabetes.

CONCLUSIONS

Education and ongoing self-management support are needed for informed decision making and the initiation and maintenance of insulin therapy. Therefore, diabetes educators have a critical role to play during both the decision-making process and the safe transition to insulin therapy.

Continuous glucose monitoring in children with type 1 diabetes: before and after insulin pump therapy

OBJECTIVE

The aim of continuous subcutaneous insulin infusion (CSII) therapy in patients with type 1 diabetes mellitus (T1DM) is to mimic as closely as possible the normal physiologic pattern seen in individuals without diabetes. This study was undertaken to determine the specific areas of improved glycemic control in subjects after initiation of insulin pump therapy and times where further improvement is needed.

RESEARCH DESIGN AND METHODS

Eight patients with T1DM (age 7.5-17 yr) wore the Continuous Glucose Monitoring System (CGMS) (Medtronic MiniMed, Northridge, CA, USA) for 3 d before and 3 months after initiation of insulin pump therapy. The CGMS, which measures inter- stitial glucose concentrations every 5 min for a 72-h period, was used to evaluate glucose profiles. Patients entered 4-5 fingerstick blood glucose measurements daily into the sensor for calibration. Detailed logs of food intake, exercise, and hypoglycemic symptoms were also recorded.

RESULTS

Hemoglobin A1c (HbA1C) was reduced (p < 0.007) following 3 months of insulin pump therapy. Post-CSII continuous glucose profiles demonstrated an overall improvement in hourly mean glucose over a 24-h period (p < 0.001) as well as a reduction in the area under the curve for glucose (27 +/- 4 prepump vs. 8.6 +/- 1.4 mg/dL/d postpump, p < 0.004). This improvement was a result of an attenuation of the maximal postprandial glycemic excursions. Postbreakfast 349 +/- 24 vs. 267 +/- 16 mg/dL, p < 0.003; lunch 340 +/- 16 vs. 217 +/- 20 mg/dL, p < 0.003. Postdinner average similarly decreased after 3 months of CSII by 22%, p < 0.04.

CONCLUSIONS

Pump therapy specifically improved the postprandial glucose excursions in children.

Dysfunction of aorta involves different patterns of intracellular signaling pathways in diabetic rats

Rat models of insulin-dependent (streptozotocin-induced) and independent (Otsuka Long-Evans Tokushima Fatty (OLETF)) diabetes had sustained and transient increases in blood glucose levels. Over-contraction due to norepinephrine was seen exclusively in streptozotocin rat aorta. Contraction was enhanced under high-glucose conditions in OLETF rats. In order to understand the association between these patterns of changes, total diacylglycerol was measured as a key element of phosphatidylinositol-turnover due to the conversion of some incorporated glucose into diacylglycerol. Streptozotocin rats had enhanced basal diacylglycerol. Both diacylglycerol kinase (metabolic enzyme of diacylglycerol) and total phosphatidylinositol turnover activities also increased on norepinephrine stimulation, independent of extracellular glucose level. On the other hand, diacylglycerol, diacylglycerol kinase and phosphatidylinositol turnover in OLETF rats increased under high glucose conditions in the absence of norepinephrine treatment. These results indicated that diacylglycerol and diacylglycerol kinase-mediated phosphatidylinositol turnover acceleration was influenced by an increase in glucose levels in OLETF rats or by receptor-mediated signals in streptozotocin rats including glucose desensitization based on submaximal incorporation. We suggest that the alteration of vascular dysfunction is induced by different factors in each type of diabetes.

Insulin glargine: a systematic review of a long-acting insulin analogue

BACKGROUND

Insulin glargine is the first long-acting basal insulin analogue indicated for subcutaneous administration once daily at bedtime in adults with type 1 or type 2 diabetes mellitus and pediatric patients aged > or = 6 years with type 1 diabetes. It differs in structure from native human insulin by 3 amino acids, a structural modification that provides a delayed onset of action and a constant, peakless effect that has a duration of at least 24 hours.

OBJECTIVE

The goal of this article was to help determine the current place in therapy of insulin glargine by reviewing all available efficacy and tolerability data published since its introduction onto the market.

METHODS

Relevant English-language articles were identified through searches of MEDLINE, PubMed, and EMBASE from 1966 to October 2002 and PREMEDLINE for November 2002. The search terms used were insulin, analogs, analogues, diabetes mellitus, glargine, HOE901, HOE-901, efficacy, safety, comparative study, treatment outcome, and case report. The reference lists of the identified articles were searched for additional relevant publications. Pharmacokinetic and pharmacodynamic data were reviewed and summarized. All large clinical trials (> or = 100 patients) evaluating the efficacy and tolerability of insulin glargine in patients with type 1 or type 2 diabetes were included in the review. Studies were compared in terms of their designs, primary and secondary efficacy parameters (glycosylated hemoglobin [HbA(1c)], fasting plasma glucose [FPG] and/or fasting blood glucose [FBG] level, incidence of hypoglycemia), and tolerability assessments.

RESULTS

Fourteen trials met the criteria for inclusion in this review, 7 of them published only in abstract form. All were multicenter, randomized, open-label, parallel-group trials conducted in Europe or the United States, and ranged in duration from 4 to 52 weeks. They compared insulin glargine with neutral protamine Hagedorn (NPH) insulin given once or twice daily in >5000 patients with type 1 or type 2 diabetes, or in insulin-naive patients with type 2 diabetes that was poorly controlled by oral antidiabetic agents. Insulin doses were individually titrated to achieve a target FBG level < or =120 mg/dL (6.7 mmol/L). The studies were typically statistically underpowered to detect a significant difference in HbA(1c) between treatment groups; only 3 trials were of an adequate size to have 90% statistical power to detect a mean 0.5% difference in HbA(1c). Furthermore, analysis of the data from these trials was associated with a number of methodologic problems relating to inconsistencies in reporting. Given these limitations, the available data suggest that insulin glargine treatment produces statistically significant reductions in FPG or FBG levels at end point both compared with baseline and compared with NPH insulin (P < 0.001) without achieving overall significant improvements in HbA(1c) values. However, a recent abstract of a small 52-week trial in patients with type 1 diabetes reported a 0.4% additional decrease in HbA(1c) with insulin glargine treatment compared with NPH insulin. Patients have reported greater treatment satisfaction with insulin glargine compared with NPH insulin. The findings varied regarding weight gain, overall incidence of hypoglycemia, and incidence of nocturnal hypoglycemia. Currently, the cost of insulin glargine is twice that of NPH insulin on a per-unit basis.

CONCLUSIONS

As a basal insulin replacement, insulin glargine administered once daily demonstrates a steady time-action profile over 24 hours without a pronounced peak. Based on the evidence from published clinical trials, insulin glargine appears to have equal clinical efficacy to NPH insulin, produces similar reductions in HbA(1c), and is associated with lower FPG and FBG levels and a consistent and significant reduction in the incidence of nocturnal hypoglycemia in patients with type 2 diabetes.

A 2-year pilot trial of continuous subcutaneous insulin infusion versus intensive insulin therapy in patients with newly diagnosed type 1 diabetes (IMDIAB 8)

In a pilot study, the metabolic effects of continuous subcutaneous insulin infusion (CSII) versus intensive subcutaneous insulin therapy (ISIT) started at diagnosis in patients with Type 1 diabetes and continued for a 2-year period were evaluated and compared. Twenty-three patients (between 12 and 35 years old, mean +/- SD 18.4 +/- 9 years) were randomized into two treatment groups (CSII vs. ISIT), and both received supplemental nicotinamide (NA), 25 mg/kg of body weight. CSII was started immediately after admission to the hospital. Parameters of metabolic control [insulin dose, hemoglobin A1c (HbA1c), and C-peptide] were evaluated for a 2-year follow-up period. Data are presented for a total of 19 patients who remained in the study for its duration. Two years after diagnosis, mean +/- SD HbA1c was 6.3 +/- 0.5% and 6.2 +/- 0.3% for the CSII and ISIT groups, respectively (p=not significant). Compared with baseline values, an increase of baseline C-peptide of 38% for the CSII group and 27% for the ISIT group was observed; however, the difference between the groups was not significant. The insulin requirement for the entire duration of the study, but not at entry and 3 months, was significantly higher in CSII compared with ISIT patients (0.62 +/- 0.4 IU/kg/day vs. 0.3 +/- 0.4 IU/kg/day, respectively; p<0.01). After trial completion patients on CSII continued with this mode of therapy. Implementation of CSII as well as ISIT at diagnosis of Type 1 diabetes and continuation for 2 years thereafter achieved similar and optimal metabolic control, but more insulin was required with the CSII group. Both types of intensive insulin therapy combined with NA are able to preserve C-peptide secretion or even increase baseline levels for up to 2 years after diagnosis.

Novel insulins: expanding options in diabetes management

Management of type 1 and type 2 diabetes mellitus with intensive insulin therapy usually includes an intermediate- or long-acting basal component for between-meal and nocturnal glycemic control, together with preprandial bolus injections of a short-acting insulin for control of meal-stimulated increases in serum glucose levels. Although the ideal basal/bolus insulin combination has yet to be found, recent developments may provide safer and more effective options. Two new short-acting semisynthetic analogs--insulin lispro and insulin aspart--can be administered as preprandial bolus injections closer to mealtime than regular human insulin, thereby synchronizing insulin administration and food absorption. In clinical trials, postprandial increases in blood glucose levels were significantly less after treatment with insulin lispro or insulin aspart than with premeal regular insulin. Because of their short duration of action, a slightly greater basal insulin supply may be needed when insulin lispro or insulin aspart is used. Inhalation devices for aerosolized regular human insulin offer another alternative to premeal subcutaneous bolus injections. Inhaled insulin is absorbed more rapidly than subcutaneous regular insulin and may therefore be given closer to mealtime. For basal therapy, insulin glargine, a new long-acting analog, is absorbed more slowly after subcutaneous administration than are conventional neutral protamine Hagedorn (NPH) and ultralente insulin, and has a relatively flat metabolic effect. Clinical trials indicate that insulin glargine is at least as effective as NPH insulin and ultralente insulin, and is associated with a reduced risk of nocturnal hypoglycemia. Other long-acting analogs, such as fatty acid acylated insulins, have been tested in animal models and are being evaluated in clinical studies.