Reduced weight gain with insulin detemir compared to NPH insulin is not explained by a reduction in hypoglycemia

Real-world study of the concomitant use of biphasic insulin aspart 30/70 with GLP-1 receptor agonist versus first-generation basal insulin with GLP-1 receptor agonist in type 2 diabetes

AIMS

Combining insulin with a glucagon-like peptide-1 receptor agonist (GLP-1RA) to treat type 2 diabetes (T2D) is common. While many studies have investigated concomitant therapy with basal insulin+GLP-1RA, few have reported on premixed insulin+GLP-1RA. We aimed to address this gap using data from the Clinical Practice Research Datalink Aurum database in England.

METHODS

This retrospective cohort study with propensity score matching assessed glycaemic levels and other clinical outcomes in people with T2D, comparing biphasic insulin aspart 30/70 (BIAsp 30) + GLP-1RA with basal insulin (insulin detemir/glargine U100) + GLP-1RA (from 2006 to 2021).

RESULTS

In total, 4770 eligible people were identified; 1511 had a BIAsp 30 + GLP-1RA regimen and were propensity score-matched to an equal number receiving basal+GLP-1RA. There was no significant difference in glycated haemoglobin (HbA1c) reduction between cohorts at 6 months (p = 0.15), with a decrease of -1.07 (95% CI: -1.16; -0.98) %-points (-11.7 mmol/mol [95% CI: -12.7; -10.7]) in the BIAsp 30 + GLP-1RA cohort, versus -0.97 (95% CI: -1.07; -0.88) %-points (-10.6 mmol/mol [95% CI: -11.7; -9.6]) in the basal+GLP-1RA cohort. Body mass index (BMI) decreased by -0.35 kg/m2 (95% CI: -0.52;-0.18) at 6 months with BIAsp 30 + GLP-1RA, versus -0.72 kg/m2 (95% CI: -0.90;-0.54) with basal+GLP-1RA (p = 0.003). BMI was influenced by the initiation sequence of GLP-1RA in relation to insulin (p < 0.0001). Hypoglycaemia rates were low and not significantly different between cohorts.

CONCLUSIONS

Combining BIAsp 30 + GLP-1RA provides glycaemic control with no significant difference to that of propensity score-matched people receiving basal insulin+GLP-1RA, with no increase in hypoglycaemia risk or weight gain.

Why does type 2 diabetes mellitus impair weight reduction in patients with obesity? A review

Background

A common adiposopathic complication of obesity is type 2 diabetes mellitus. Healthful weight reduction in patients with obesity can improve glucose metabolism and potentially promote remission of type 2 diabetes mellitus. However, weight-reduction in patients with increased adiposity is impaired among patients with type 2 diabetes mellitus compared to patients without diabetes mellitus.

Methods

Data for this review were derived from PubMed and applicable websites.

Results

Among patients with increased body fat, the mechanisms underlying impaired weight reduction for those with type 2 diabetes mellitus are multifactorial, and include energy conservation (i.e., improved glucose control and reduced glucosuria), hyperinsulinemia (commonly found in many patients with type 2 diabetes mellitus), potential use of obesogenic anti-diabetes medications, and contributions from multiple body systems. Other factors include increased age, sex, genetic/epigenetic predisposition, and obesogenic environments.

Conclusions

Even though type 2 diabetes mellitus impairs weight reduction among patients with increased adiposity, clinically meaningful weight reduction improves glucose metabolism and can sometimes promote diabetes remission. An illustrative approach to mitigate impaired weight reduction due to type 2 diabetes mellitus is choosing anti-diabetes medications that increase insulin sensitivity and promote weight loss and deprioritize use of anti-diabetes medications that increase insulin exposure and promote weight gain.

(Ultra-)long-acting insulin analogues versus NPH insulin (human isophane insulin) for adults with type 2 diabetes mellitus

BACKGROUND

Evidence that antihyperglycaemic therapy is beneficial for people with type 2 diabetes mellitus is conflicting. While the United Kingdom Prospective Diabetes Study (UKPDS) found tighter glycaemic control to be positive, other studies, such as the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, found the effects of an intensive therapy to lower blood glucose to near normal levels to be more harmful than beneficial. Study results also showed different effects for different antihyperglycaemic drugs, regardless of the achieved blood glucose levels. In consequence, firm conclusions on the effect of interventions on patient-relevant outcomes cannot be drawn from the effect of these interventions on blood glucose concentration alone. In theory, the use of newer insulin analogues may result in fewer macrovascular and microvascular events.

OBJECTIVES

To compare the effects of long-term treatment with (ultra-)long-acting insulin analogues (insulin glargine U100 and U300, insulin detemir and insulin degludec) with NPH (neutral protamine Hagedorn) insulin (human isophane insulin) in adults with type 2 diabetes mellitus.

SEARCH METHODS

For this Cochrane Review update, we searched CENTRAL, MEDLINE, Embase, ICTRP Search Portal and ClinicalTrials.gov. The date of the last search was 5 November 2019, except Embase which was last searched 26 January 2017. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing the effects of treatment with (ultra-)long-acting insulin analogues to NPH in adults with type 2 diabetes mellitus.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed risk of bias, extracted data and evaluated the overall certainty of the evidence using GRADE. Trials were pooled using random-effects meta-analyses.

MAIN RESULTS

We identified 24 RCTs. Of these, 16 trials compared insulin glargine to NPH insulin and eight trials compared insulin detemir to NPH insulin. In these trials, 3419 people with type 2 diabetes mellitus were randomised to insulin glargine and 1321 people to insulin detemir. The duration of the included trials ranged from 24 weeks to five years. For studies, comparing insulin glargine to NPH insulin, target values ranged from 4.0 mmol/L to 7.8 mmol/L (72 mg/dL to 140 mg/dL) for fasting blood glucose (FBG), from 4.4 mmol/L to 6.6 mmol/L (80 mg/dL to 120 mg/dL) for nocturnal blood glucose and less than 10 mmol/L (180 mg/dL) for postprandial blood glucose, when applicable. Blood glucose and glycosylated haemoglobin A1c (HbA1c) target values for studies comparing insulin detemir to NPH insulin ranged from 4.0 mmol/L to 7.0 mmol/L (72 mg/dL to 126 mg/dL) for FBG, less than 6.7 mmol/L (120 mg/dL) to less than 10 mmol/L (180 mg/dL) for postprandial blood glucose, 4.0 mmol/L to 7.0 mmol/L (72 mg/dL to 126 mg/dL) for nocturnal blood glucose and 5.8% to less than 6.4% HbA1c, when applicable. All trials had an unclear or high risk of bias for several risk of bias domains. Overall, insulin glargine and insulin detemir resulted in fewer participants experiencing hypoglycaemia when compared with NPH insulin. Changes in HbA1c were comparable for long-acting insulin analogues and NPH insulin. Insulin glargine compared to NPH insulin had a risk ratio (RR) for severe hypoglycaemia of 0.68 (95% confidence interval (CI) 0.46 to 1.01; P = 0.06; absolute risk reduction (ARR) -1.2%, 95% CI -2.0 to 0; 14 trials, 6164 participants; very low-certainty evidence). The RR for serious hypoglycaemia was 0.75 (95% CI 0.52 to 1.09; P = 0.13; ARR -0.7%, 95% CI -1.3 to 0.2; 10 trials, 4685 participants; low-certainty evidence). Treatment with insulin glargine reduced the incidence of confirmed hypoglycaemia and confirmed nocturnal hypoglycaemia. Treatment with insulin detemir compared to NPH insulin found an RR for severe hypoglycaemia of 0.45 (95% CI 0.17 to 1.20; P = 0.11; ARR -0.9%, 95% CI -1.4 to 0.4; 5 trials, 1804 participants; very low-certainty evidence). The Peto odds ratio for serious hypoglycaemia was 0.16, 95% CI 0.04 to 0.61; P = 0.007; ARR -0.9%, 95% CI -1.1 to -0.4; 5 trials, 1777 participants; low-certainty evidence). Treatment with detemir also reduced the incidence of confirmed hypoglycaemia and confirmed nocturnal hypoglycaemia. Information on patient-relevant outcomes such as death from any cause, diabetes-related complications, health-related quality of life and socioeconomic effects was insufficient or lacking in almost all included trials. For those outcomes for which some data were available, there were no meaningful differences between treatment with glargine or detemir and treatment with NPH. There was no clear difference between insulin-analogues and NPH insulin in terms of weight gain. The incidence of adverse events was comparable for people treated with glargine or detemir, and people treated with NPH. We found no trials comparing ultra-long-acting insulin glargine U300 or insulin degludec with NPH insulin.

AUTHORS' CONCLUSIONS

While the effects on HbA1c were comparable, treatment with insulin glargine and insulin detemir resulted in fewer participants experiencing hypoglycaemia when compared with NPH insulin. Treatment with insulin detemir also reduced the incidence of serious hypoglycaemia. However, serious hypoglycaemic events were rare and the absolute risk reducing effect was low. Approximately one in 100 people treated with insulin detemir instead of NPH insulin benefited. In the studies, low blood glucose and HbA1c targets, corresponding to near normal or even non-diabetic blood glucose levels, were set. Therefore, results from the studies are only applicable to people in whom such low blood glucose concentrations are targeted. However, current guidelines recommend less-intensive blood glucose lowering for most people with type 2 diabetes in daily practice (e.g. people with cardiovascular diseases, a long history of type 2 diabetes, who are susceptible to hypoglycaemia or older people). Additionally, low-certainty evidence and trial designs that did not conform with current clinical practice meant it remains unclear if the same effects will be observed in daily clinical practice. Most trials did not report patient-relevant outcomes.

Impact of Weight Change in Adults with Type 2 Diabetes Mellitus: A Literature Review and Critical Analysis

Objective

Weight reduction is a key component of diabetes management in adults with type 2 diabetes mellitus (T2DM), yet the benefits of weight loss in T2DM patients have been difficult to quantify. We examined the medical literature regarding the relationships between weight change and 1) glycemic control and 2) cost and resource use.

Methods

Systematic searches were conducted in the electronic databases Embase, MEDLINE, and the Cochrane Database of Systematic Reviews to identify publications regarding the impact of weight change on T2DM outcomes from 2007 onward. Identified publications were screened for relevance against predefined eligibility criteria, and methodological approaches and results were extracted. Evidence for the impact of weight change on outcomes was evaluated and used to identify strengths, limitations, and gaps in the current literature.

Results

The number of studies meeting eligibility criteria for each outcome was: glycemic control (n=38) and cost and resource use (n=11). The relationship between weight change and glycemic control was dependent on the interplay of multiple factors, eg, the weight loss interventions employed, the antidiabetic medication classes used, the time horizon, and baseline BMI and glycemic control. With respect to cost and resource use, the review indicated that savings were associated with weight loss, and increased costs were associated with weight gain.

Conclusion

Studies regarding weight change in T2DM patients demonstrated varying effects on glycemic control and a positive association with costs and resource use, where weight loss was associated with decreased costs and resource use. Future studies may be able to clarify these relationships.

Insulin-associated weight gain in obese type 2 diabetes mellitus patients: What can be done?

Insulin therapy (IT) is initiated for patients with type 2 diabetes mellitus when glycaemic targets are not met with diet and other hypoglycaemic agents. The initiation of IT improves glycaemic control and reduces the risk of microvascular complications. There is, however, an associated weight gain following IT, which may adversely affect diabetic and cardiovascular morbidity and mortality. A 3 to 9 kg insulin-associated weight gain (IAWG) is reported to occur in the first year of initiating IT, predominantly caused by adipose tissue. The potential causes for this weight gain include an increase in energy intake linked to a fear of hypoglycaemia, a reduction in glycosuria, catch-up weight, and central effects on weight and appetite regulation. Patients with type 2 diabetes who are receiving IT often have multiple co-morbidities, including obesity, that are exacerbated by weight gain, making the management of their diabetes and obesity challenging. There are several treatment strategies for patients with type 2 diabetes, who require IT, that attenuate weight gain, help improve glycaemic control, and help promote body weight homeostasis. This review addresses the effects of insulin initiation and intensification on IAWG, and explores its potential underlying mechanisms, the predictors for this weight gain, and the available treatment options for managing and limiting weight gain.

Weight effects of antidiabetic agents

Obesity and diabetes are on the rise, which remains a continuous health concern worldwide. It is important to consider weight effects of antidiabetic agents prior to initiation as different antidiabetic agents impact weight differently. Areas covered: New agents to treat diabetes, glucagon-like peptide-1 receptor agonists and sodium glucose cotransporter 2 inhibitors, have emerged over recent years that have been shown to result in weight reduction. Unfortunately, other antidiabetic medications used can cause weight gain such as with insulin, sulfonylureas, and thiazolidediones while some remain weight neutral (metformin and dipeptidyl peptidase-4 inhibitors). The weight effects of these antidiabetic medications described are from select relevant guidelines, clinical trials, reviews, and meta-analysis found through PubMed and Ovid databases up to July 2017. Expert commentary: This article summarizes the current evidence available on the weight effects of these agents in patients with diabetes. Evaluating potential risks, such as weight gain, with potential benefits, such as improvement in glycemic control, will help with designing optimal therapeutic diabetes regimens.

The past, present, and future of basal insulins

Insulin production by the pancreas follows a basic pattern where basal levels of insulin are secreted during fasting periods, with prandial increases in insulin associated with food ingestion. The aim of insulin therapy in patients with diabetes is to match the endogenous pattern of insulin secretion as closely as possible without causing hypoglycaemia. There are several optimal pharmacokinetic and pharmacodynamic properties of long-acting basal insulins that can help to achieve this aim, namely, as follows: activity that is flat and as free of peaks as possible, a duration of action of ≥24-h, and as little day-to-day variation as possible. The long-acting basal insulins are a fundamental therapy for patients with type 1 and type 2 diabetes, and those that are currently available have many benefits; however, the development of even longer-acting insulins and improved insulin delivery techniques may lead to better glycemic control for patients in the future. Established long-acting basal insulins available in the United States and Europe include insulin glargine 100 units/mL and insulin detemir, both of which exhibit similar glycemic control to that of the intermediate-acting neutral protamine Hagedorn insulin, but with a reduction in hypoglycaemia. Newer insulin products available include new insulin glargine 300 units/mL (United States and Europe) and the ultra-long-acting insulin degludec (Europe) with basal insulin peglispro currently in development. These new insulins demonstrate different pharmacokinetic/pharmacodynamic profiles and longer durations of action (>24 h) compared with insulin glargine 100 units/mL, which may lead to potential benefits. The introduction of biosimilar insulins may also broaden access to insulins by reducing treatment costs. Copyright © 2015 John Wiley & Sons, Ltd.

Weight-sparing effect of insulin detemir: a consequence of central nervous system-mediated reduced energy intake?

Insulin therapy is often associated with adverse weight gain. This is attributable, at least in part, to changes in energy balance and insulin's anabolic effects. Adverse weight gain increases the risk of poor macrovascular outcomes in people with diabetes and should therefore be mitigated if possible. Clinical studies have shown that insulin detemir, a basal insulin analogue, exerts a unique weight-sparing effect compared with other basal insulins. To understand this property, several hypotheses have been proposed. These explore the interplay of efferent and afferent signals between the muscles, brain, liver, renal and adipose tissues in response to insulin detemir and comparator basal insulins. The following models have been proposed: insulin detemir may reduce food intake through direct or indirect effects on the central nervous system (CNS); it may have favourable actions on hepatic glucose metabolism through a selective effect on the liver, or it may influence fluid homeostasis through renal effects. Studies have consistently shown that insulin detemir reduces energy intake, and moreover, it is clear that this shift in energy balance is not a consequence of reduced hypoglycaemia. CNS effects may be mediated by direct action, by indirect stimulation by peripheral mediators and/or via a more physiological counter-regulatory response to insulin through restoration of the hepatic-peripheral insulin gradient. Although the precise mechanism remains unclear, it is likely that the weight-sparing effect of insulin detemir can be explained by a combination of mechanisms. The evidence for each hypothesis is considered in this review.

Effects of insulin detemir and NPH insulin on body weight and appetite-regulating brain regions in human type 1 diabetes: a randomized controlled trial

Studies in rodents have demonstrated that insulin in the central nervous system induces satiety. In humans, these effects are less well established. Insulin detemir is a basal insulin analog that causes less weight gain than other basal insulin formulations, including the current standard intermediate-long acting Neutral Protamine Hagedorn (NPH) insulin. Due to its structural modifications, which render the molecule more lipophilic, it was proposed that insulin detemir enters the brain more readily than other insulins. The aim of this study was to investigate whether insulin detemir treatment differentially modifies brain activation in response to food stimuli as compared to NPH insulin. In addition, cerebral spinal fluid (CSF) insulin levels were measured after both treatments. Brain responses to viewing food and non-food pictures were measured using functional Magnetic Resonance Imaging in 32 type 1 diabetic patients, after each of two 12-week treatment periods with insulin detemir and NPH insulin, respectively, both combined with prandial insulin aspart. CSF insulin levels were determined in a subgroup. Insulin detemir decreased body weight by 0.8 kg and NPH insulin increased weight by 0.5 kg (p = 0.02 for difference), while both treatments resulted in similar glycemic control. After treatment with insulin detemir, as compared to NPH insulin, brain activation was significantly lower in bilateral insula in response to visual food stimuli, compared to NPH (p = 0.02 for right and p = 0.05 for left insula). Also, CSF insulin levels were higher compared to those with NPH insulin treatment (p = 0.003). Our findings support the hypothesis that in type 1 diabetic patients, the weight sparing effect of insulin detemir may be mediated by its enhanced action on the central nervous system, resulting in blunted activation in bilateral insula, an appetite-regulating brain region, in response to food stimuli.

Trial Registration

ClinicalTrials.gov NCT00626080.

Cerebral blood flow and glucose metabolism in appetite-related brain regions in type 1 diabetic patients after treatment with insulin detemir and NPH insulin: a randomized controlled crossover trial

OBJECTIVE

To test the hypothesis that insulin detemir, which is associated with less weight gain than other basal insulin formulations, exerts its weight-modulating effects by acting on brain regions involved in appetite regulation, as represented by altered cerebral blood flow (CBF) or cerebral glucose metabolism (CMRglu).

RESEARCH DESIGN AND METHODS

Twenty-eight male type 1 diabetic patients (age 36.9 ± 9.7 years, BMI 24.9 ± 2.7 kg/m(2), A1C 7.5 ± 0.6%) successfully completed a randomized crossover study, consisting of two periods of 12-week treatment with either insulin detemir or NPH insulin, both in combination with prandial insulin aspart. After each treatment period, patients underwent positron emission tomography scans to measure regional CBF and CMRglu.

RESULTS

After 12 weeks, A1C, daily insulin doses, fasting insulin, and blood glucose levels were similar between treatments. Insulin detemir resulted in body weight loss, whereas NPH insulin induced weight gain (between-treatment difference 1.3 kg; P = 0.02). After treatment with insulin detemir relative to NPH insulin, CBF was higher in brain regions involved in appetite regulation, whereas no significant difference in CMRglu was observed.

CONCLUSIONS

Treatment with insulin detemir versus NPH insulin resulted in weight loss, paralleled by increased CBF in appetite-related brain regions in the resting state, in men with well-controlled type 1 diabetes. These findings lend support to the hypothesis that a differential effect on the brain may contribute to the consistently observed weight-sparing effect of insulin detemir.

The comparison of 24-hour urinary sodium, albumin, and protein excretion in chronic kidney disease patients with type 2 diabetes mellitus using insulin detemir or insulin glargine

BACKGROUND AND OBJECTIVE

Insulin detemir induces bodyweight loss or less weight gain in patients with type 2 diabetes mellitus. However, in contrast to insulin detemir, insulin glargine has no weight loss effect. Increased sodium excretion has been speculated to be one of the mechanisms of weight loss by insulin detemir. However, there are no studies in the literature comparing sodium excretion between patients using insulin detemir and those using insulin glargine. There are also no studies comparing the excretion of urinary albumin and urinary protein in chronic kidney disease (CKD) patients using insulin detemir or insulin glargine. Thus, the aim of the current study was to compare the effects of insulin detemir and insulin glargine on sodium, albumin, and protein excretion in patients with various stages of CKD and concomitant type 2 diabetes.

METHODS

Demographic, clinical, and laboratory data were evaluated for all patients. Hypoglycemic attacks, appetite score, 24-h urinary sodium, albumin, and protein excretion were also measured.

RESULTS

A total of 47 patients (23 taking insulin detemir, 24 taking insulin glargine) were included in the study. There were no differences with respect to 24-h sodium (p = 0.694), albumin (p = 0.297), or protein excretion (p = 0.202) between patient groups. Appetite and hypoglycemic attacks also did not differ between groups. Use of insulin detemir or insulin glargine was not related to sodium, albumin, and protein excretion in stepwise regression analysis.

CONCLUSION

There was no difference between insulin detemir and insulin glargine with respect to sodium, albumin, and protein excretion in type 2 diabetic CKD patients. Studies are needed both in CKD patients and those with normal renal function to highlight mechanisms regarding the weight loss effect unique to insulin detemir.

Insulin detemir: a review of its use in the management of diabetes mellitus

Insulin detemir (Levemir®) is a long-acting insulin analogue indicated for use as basal insulin therapy in patients with type 1 or 2 diabetes mellitus. The protracted action of insulin detemir is explained by increased self-association and reversible binding to albumin, which slows its systemic absorption from the injection site. In glucose-clamp studies, less within-patient variability in glucose-lowering effect was seen with insulin detemir than with neutral protamine Hagedorn (NPH) insulin or insulin glargine in patients with type 1 or 2 diabetes. The beneficial effect of insulin detemir on glycaemic control was shown in numerous randomized, open-label, multicentre trials, including when used as basal-bolus therapy in patients with type 1 or 2 diabetes and as basal therapy in addition to oral antidiabetic drugs in insulin-naive patients with type 2 diabetes. In terms of glycosylated haemoglobin (HbA(1c)).[primary endpoint in most trials], insulin detemir was generally at least as effective as NPH insulin, insulin glargine or insulin lispro protamine suspension in patients with type 1 or 2 diabetes, and at least as effective as biphasic insulin aspart in patients with type 2 diabetes. Less within-patient variability in blood glucose was also generally seen with insulin detemir than with NPH insulin in patients with type 1 or 2 diabetes. Significantly less weight gain was generally seen with insulin detemir than with NPH insulin in patients with type 1 diabetes or with insulin detemir than with NPH insulin, insulin glargine, insulin lispro protamine suspension or biphasic insulin aspart (in one study) in patients with type 2 diabetes (i.e. insulin detemir generally had a weight-sparing effect). The addition of insulin detemir to liraglutide plus metformin improved glycaemic control in insulin-naive patients with type 2 diabetes and inadequate glycaemic control, although a significantly greater reduction in bodyweight was seen in patients receiving liraglutide plus metformin than in those receiving add-on therapy with insulin detemir. Results of two trials in patients aged 2-16 or 6-17 years (and a subgroup analysis in children aged 2-5 years) indicate that a basal-bolus insulin regimen incorporating insulin detemir appears to be a suitable option for use in paediatric patients with type 1 diabetes. Less within-patient variation in self-measured fasting plasma glucose was seen with insulin detemir than with NPH insulin in one of the studies. Insulin detemir was noninferior to NPH insulin in pregnant women with type 1 diabetes in terms of the HbA(1c) value achieved at 36 gestational weeks. In addition, maternal and neonatal outcomes with insulin detemir were similar to those seen with NPH insulin. Subcutaneous insulin detemir was generally well tolerated in the treatment of patients with type 1 or 2 diabetes, including in paediatric patients and pregnant women with type 1 diabetes. The majority of adverse events, including serious adverse events, reported in insulin detemir recipients were not considered to be related to the study drug. Insulin detemir was generally associated with a significantly lower risk of nocturnal hypoglycaemia than NPH insulin in patients with type 1 or 2 diabetes, particularly nocturnal minor hypoglycaemia. In conclusion, insulin detemir is a useful option for use as basal insulin therapy in patients with type 1 or 2 diabetes.

Diabetes therapy--focus on Asia: second-line therapy debate: insulin/secretagogues

The following review is based on the second part of a debate entitled 'Diabetes therapy--focus on Asia: 2nd line therapy: GLP1/DPP4 inhibitors versus Secretagogue/insulin therapy', which was held during the '1st Asia Pacific Congress on Controversies to Consensus in Diabetes, Obesity and Hypertension (CODHy)', in Shanghai, China, 2011. As such we reviewed only insulin and secretagogue therapy despite the existence of other therapeutic options. The article aims to shed light on the circumstances most adequate for use of these as second-line agents, despite possible drawbacks. It is important to emphasize that regardless of it being a review of published evidence, it primarily represents the professional opinion of the writers.

Insulin in the brain: there and back again

Insulin performs unique functions within the CNS. Produced nearly exclusively by the pancreas, insulin crosses the blood-brain barrier (BBB) using a saturable transporter, affecting feeding and cognition through CNS mechanisms largely independent of glucose utilization. Whereas peripheral insulin acts primarily as a metabolic regulatory hormone, CNS insulin has an array of effects on brain that may more closely resemble the actions of the ancestral insulin molecule. Brain endothelial cells (BECs), the cells that form the vascular BBB and contain the transporter that translocates insulin from blood to brain, are themselves regulated by insulin. The insulin transporter is altered by physiological and pathological factors including hyperglycemia and the diabetic state. The latter can lead to BBB disruption. Pericytes, pluripotent cells in intimate contact with the BECs, protect the integrity of the BBB and its ability to transport insulin. Most of insulin's known actions within the CNS are mediated through two canonical pathways, the phosphoinositide-3 kinase (PI3)/Akt and Ras/mitogen activated kinase (MAPK) cascades. Resistance to insulin action within the CNS, sometimes referred to as diabetes mellitus type III, is associated with peripheral insulin resistance, but it is possible that variable hormonal resistance syndromes exist so that resistance at one tissue bed may be independent of that at others. CNS insulin resistance is associated with Alzheimer's disease, depression, and impaired baroreceptor gain in pregnancy. These aspects of CNS insulin action and the control of its entry by the BBB are likely only a small part of the story of insulin within the brain.

Brain meets body: the blood-brain barrier as an endocrine interface

The blood-brain barrier (BBB) separates the central nervous system (CNS) from the peripheral tissues. However, this does not prevent hormones from entering the brain, but shifts the main control of entry to the BBB. In general, steroid hormones cross the BBB by transmembrane diffusion, a nonsaturable process resulting in brain levels that reflect blood levels, whereas thyroid hormones and many peptides and regulatory proteins cross using transporters, a saturable process resulting in brain levels that reflect blood levels and transporter characteristics. Protein binding, brain-to-blood transport, and pharmacokinetics modulate BBB penetration. Some hormones have the opposite effect within the CNS than they do in the periphery, suggesting that these hormones cross the BBB to act as their own counterregulators. The cells making up the BBB are also endocrine like, both responding to circulating substances and secreting substances into the circulation and CNS. By dividing a hormone's receptors into central and peripheral pools, the former of which may not be part of the hormone's negative feed back loop, the BBB fosters the development of variable hormone resistance syndromes, as exemplified by evidence that altered insulin action in the CNS can contribute to Alzheimer's disease. In summary, the BBB acts as a regulatory interface in an endocrine-like, humoral-based communication between the CNS and peripheral tissues.

Insulin degludec as an ultralong-acting basal insulin once a day: a systematic review

BACKGROUND

Insulin degludec (IDeg) is a neutral, ultralong-acting new generation basal insulin analog developed by NovoNordisk currently in Phase III clinical development. IDeg offers a duration of action of more than 42 hours in adults, much longer than current basal insulin formulations.

OBJECTIVE

The aim of this review is to assess the efficacy and safety data of IDeg in the treatment of type 1 and type 2 diabetes mellitus.

METHODS

Relevant English language articles from 2010 to 2012 were identified through MEDLINE, PubMed, EMBASE, Scopus, BIOSIS, and Google Scholar. Online conference proceedings of the 71st ADA Scientific Sessions and the 47th EASD Annual Meeting were reviewed. Studies were compared in terms of their study designs, primary and secondary efficacy parameters, and tolerability data.

RESULTS

There are a total of nine published trials investigating the clinical efficacy and safety of IDeg in over 3000 subjects with type 1 and 2 diabetes. Only three trials were published in full. All were open-label, randomized multicenter trials with durations of 16 to 52 weeks. IDeg and coformulations of IDeg with insulin aspart (IAsp) were compared to insulin glargine (IGlar), detemir, and biphasic IAsp 30 (BIAsp 30).

CONCLUSION

Based upon the available evidence, there appear to be no reported differences between IDeg and IGlar, detemir, or BIAsp 30 in the reduction of the primary efficacy end-points of HbA(1c) and mean fasting plasma glucose (FPG) concentrations. Only flexible dosing of IDeg provided a significant reduction in FPG compared to IGlar. IDeg demonstrated a significant reduction in nocturnal hypoglycemia in type 1 diabetes. In type 2 diabetes, IDeg reduced the incidence of hypoglycemia by 18% and 58% compared to IGlar and BIAsp 30, respectively.

Patient empowerment and optimal glycemic control

OBJECTIVE

This review updates the clinician on strategies of insulin use and educational approaches to empower their patients to use insulin correctly in self-management treatment plans.

DESIGN AND METHODS

A PubMed literature search was conducted to identify peer-reviewed clinical trials published in English in the last 10 years. Search terms used were 'glycemic control', 'insulin', and 'type 2 diabetes'. An additional search to include the terms 'patient empowerment' and 'self-management' was also conducted. Some articles relevant to this review may not have been identified using these terms. Oral antidiabetes agents in conjunction with insulin are not addressed.

RESULTS

A total of 562 articles were initially identified. Papers that did not provide data pertinent to the efficacy and tolerance of insulin types for treatment of type 2 diabetes mellitus (T2DM) were excluded. Based on methodology, results, and clinical implications, 12 clinical trials were included for discussion in this review.

CONCLUSIONS

Patients with T2DM who are empowered with knowledge about their disease and treatment can take an active role in their diabetes care, and therefore, are more likely to achieve blood glucose and A1C goals, which can slow progression of their disease and the onset of complications. Although concentrating solely on medical information and physiological facts does not guarantee patient empowerment and self-management, educational strategies such as interactive teaching, problem solving and individualized education can have a positive impact. Insulin titration algorithms can empower patients to manage their therapy, and such algorithms are simple to use for patients treated with insulin analogs. As patients with T2DM become empowered by knowledge and gain more control of their disease, their physicians must then serve as their advisors rather than as their directors or prescribers.

Receptor-isoform-selective insulin analogues give tissue-preferential effects

The relative expression patterns of the two IR (insulin receptor) isoforms, +/- exon 11 (IR-B/IR-A respectively), are tissue-dependent. Therefore we have developed insulin analogues with different binding affinities for the two isoforms to test whether tissue-preferential biological effects can be attained. In rats and mice, IR-B is the most prominent isoform in the liver (> 95%) and fat (> 90%), whereas in muscles IR-A is the dominant isoform (> 95%). As a consequence, the insulin analogue INS-A, which has a higher relative affinity for human IR-A, had a higher relative potency [compared with HI (human insulin)] for glycogen synthesis in rat muscle strips (26%) than for glycogen accumulation in rat hepatocytes (5%) and for lipogenesis in rat adipocytes (4%). In contrast, the INS-B analogue, which has an increased affinity for human IR-B, had higher relative potencies (compared with HI) for inducing glycogen accumulation (75%) and lipogenesis (130%) than for affecting muscle (45%). For the same blood-glucose-lowering effect upon acute intravenous dosing of mice, INS-B gave a significantly higher degree of IR phosphorylation in liver than HI. These in vitro and in vivo results indicate that insulin analogues with IR-isoform-preferential binding affinity are able to elicit tissue-selective biological responses, depending on IR-A/IR-B expression.

Insulin detemir for the treatment of obese patients with type 2 diabetes

The risk for developing type 2 diabetes (T2DM) is greater among obese individuals. Following onset of the disease, patients with T2DM become more likely to be afflicted with diabetic micro- and macrovascular complications. Decreasing body weight has been shown to lower glycosylated hemoglobin and improve other metabolic parameters in patients with T2DM. Medications used to lower blood glucose may increase body weight in patients with T2DM and this has been repeatedly shown to be the case for conventional, human insulin formulations. Insulin detemir is a neutral, soluble, long-acting insulin analog in which threonine-30 of the insulin B-chain is deleted, and the C-terminal lysine is acetylated with myristic acid, a C14 fatty acid chain. Insulin detemir binds to albumin, a property that enhances its pharmacokinetic/pharmacodynamic profile. Results from clinical trials have demonstrated that treatment with insulin detemir is associated with less weight gain than either insulin glargine or neutral protamine Hagedorn insulin. There are many potential reasons for the lower weight gain observed among patients treated with insulin detemir, including lower risk for hypoglycemia and therefore decreased defensive eating due to concern about this adverse event, along with other effects that may be related to the albumin binding of this insulin that may account for lower within-patient variability and consistent action. These might include faster transport across the blood-brain barrier, induction of satiety signaling in the brain, and preferential inhibition of hepatic glucose production versus peripheral glucose uptake. Experiments in diabetic rats have also indicated that insulin detemir increases adiponectin levels, which is associated with both weight loss and decreased eating.

Effect of insulin analogues on 3t3-l1 adipogenesis and lipolysis

BACKGROUND

Insulin has several biological functions besides glycaemic control. We investigated and compared the effects of six different commercial insulins on adipocyte cell differentiation, the lipolytic activity of differentiated cells, and the expression levels of genes involved in adipogenesis and associated with insulin activity.

MATERIALS AND METHODS

3T3-L1 cells were induced to differentiate with six commercial insulins: glargine, lispro, aspart, detemir, NPH and regular recombinant human insulin (used as control). Cell differentiation, lipolysis and gene expression were measured at day 7 (D7) and day 10 (D10) after induction of differentiation in these cells.

RESULTS

The highest values of cell differentiation and lipolysis were found at D10 for all the insulins used. Preadipocyte differentiation differed at both times depending on the insulin used, with detemir insulin being the least adipogenic. The PPARγ mRNA level varied according to the insulin and was a good genetic marker of adipogenesis at D7. Cells treated with glargine insulin showed the highest lipolysis and HSL expression on both days. Gene expression levels of InsR, SREBP-1c and SCD-1 differed depending on the insulin studied.

CONCLUSIONS

Detemir insulin was the least adipogenic of the insulins tested, whereas treatment with glargine insulin tended to produce the highest lipolysis levels. Under these experimental conditions, the modifications made in commercial insulins to improve glycaemic control also affect adipocyte differentiation, the lipolysis level of differentiated cells, and the expression of different genes that can modify metabolic pathways independently of glucose metabolism.

Detemir as a once-daily basal insulin in type 2 diabetes

Background

Insulin detemir, a long-acting basal insulin analog, is labeled for once-daily or twice-daily dosing in patients with type 1 (T1DM) or type 2 (T2DM) diabetes mellitus. Protocols for some earlier clinical studies of detemir evaluated twice-daily dosing, which may have generated the misperception that detemir should be prescribed twice daily for most patients. This review examines pharmacokinetic and pharmacodynamic (PK/PD), observational, and controlled studies that have evaluated once-daily and twice-daily detemir in patients with T2DM to determine the efficacy and safety of once-daily dosing.

Methods

PubMed was searched using the keywords “detemir,” “once daily,” “twice daily,” and “type 2 diabetes” with the limits of clinical trial, human, and English.

Results

Detemir has a relatively flat time–action profile and duration of action of up to 24 hours for patients with T2DM. Once-daily dosing is the most commonly used detemir regimen reported in observational studies, and controlled clinical studies indicate that once-daily dosing controls glycosylated hemoglobin when detemir is administered alone or in combination with a prandial insulin or oral antidiabetes drugs. In comparative clinical trials, detemir had a similar time–action profile and duration of action to another long-acting insulin analog, glargine, with less within-subject variability. Once-daily detemir was associated with no weight gain or less weight gain than comparator regimens. For patients who had not achieved glycemic control with a basal dose of once-daily detemir, adding a prandial insulin provided better glycemic control, less postprandial hypoglycemia, and a lower total daily dose of detemir than twice-daily detemir. Involvement of a multidisciplinary team and the use of a holistic approach for the treatment of T2DM patients are recommended to achieve and maintain the best patient outcomes.

Conclusion

Results from PK/PD, observational, and controlled clinical studies support a once-daily detemir regimen alone or in combination with a prandial insulin or oral antidiabetes drugs.

Insulin detemir reduces weight gain as a result of reduced food intake in patients with type 1 diabetes

OBJECTIVE

Insulin detemir lacks the usual propensity for insulin to cause weight gain. We investigated whether this effect was a result of reduced energy intake and/or increased energy expenditure.

RESEARCH DESIGN AND METHODS

A 32-week, randomized crossover design trial was undertaken in 23 patients with type 1 diabetes. Patients on a basal-bolus regimen (with insulin aspart as the bolus insulin) were randomly assigned to insulin detemir or NPH insulin as a basal insulin for 16 weeks, followed by the other basal insulin for 16 weeks. At the end of each 16-week period, total energy expenditure, resting energy expenditure, diet-induced thermogenesis, activity energy expenditure, energy intake, weight change, glycemic control, hypoglycemic episodes, and hormones that affect satiety and fuel partitioning were measured.

RESULTS

After 16 weeks, weight change was -0.69±1.85 kg with insulin detemir and +1.7±2.46 kg with NPH insulin (P<0.001). Total energy intake was significantly less with insulin detemir (2,016±501 kcal/day) than with NPH insulin (2,181±559 kcal/day) (P=0.026). There was no significant difference in any measure of energy expenditure, HbA1c percentage, or number of hypoglycemic episodes. Leptin was lower and resistin was higher with insulin detemir compared with NPH insulin (P=0.039, P=0.047). After the meal, ghrelin and pancreatic polypeptide levels (P=0.002, P=0.001) were higher with insulin detemir.

CONCLUSIONS

The reduced weight gain with insulin detemir compared with NPH insulin is attributed to reduced energy intake rather than increased energy expenditure. This may be mediated by a direct or indirect effect of insulin detemir on the hormones that control satiety.

Insulin detemir is not transported across the blood-brain barrier

Insulin detemir has a different profile of action on the central nervous system (CNS) than human insulin. It has been hypothesized that this is caused by an altered ability of insulin detemir to cross the blood-brain barrier (BBB). Here, we measured the permeability of the BBB to insulin detemir. We labeled insulin detemir with radioactive iodine (I-Det) and examined its ability to cross the BBB of the mouse. Permeation was assessed after intravenous injection and by brain perfusion in the presence or absence of excess insulin detemir. The ability of insulin detemir to inhibit human insulin transport across the BBB was also assessed. I-Det did not cross the BBB either after intravenous injection or when studied by brain perfusion, a method which removes or reduces the influence of circulating proteins. Unlabeled detemir was about 10 times less potent than human insulin at inhibiting the transport of radioactive human insulin across the BBB. The altered CNS profile of insulin detemir may be caused by its poor access to CNS receptors and by a block of human insulin from crossing the BBB.

Are analogue insulins superior to human insulin in clinical practice?

Insulin analogues were designed to provide more physiologic pharmacokinetic and pharmacodynamic properties compared with human insulin. This article examines the literature over a 2-year period, focusing on studies directly comparing analogue and human insulin in controlled clinical trials and large observational studies documenting the introduction of, or change to, analogue insulin in clinical practice. Findings indicate that analogues provide objective benefits that include improved glycemic control, lower risk of hypoglycemia, lower glucose variability, and (for insulin detemir) reduced weight gain. Recent data with analogues also explore their safety and efficacy in special patient groups such as children and adolescents. These data complement increasing evidence that analogues offer improved acceptability and accessibility to people with diabetes.

An update on the treatment of type 1 and type 2 diabetes mellitus: focus on insulin detemir, a long-acting human insulin analog

Basal insulin analogs are used to minimize unpredictable processes of NPH insulin. Modification of the human insulin molecule results in a slower distribution to peripheral target tissues, a longer duration of action with stable concentrations and thus a lower rate of hypoglycemia. Insulin detemir is a basal insulin analog that provides effective therapeutic options for patients with type 1 and type 2 diabetes. For glycemic control, no significant differences were found in HbA_1c levels compared with NPH and insulin glargine. It is comparable with insulin glargine in significantly reducing rates of all types of hypoglycemia. Clinical studies have demonstrated that detemir is responsible for significantly lower within-subject variability and no or less weight gain than NPH insulin and glargine. Recent pharmacodynamic studies have shown that detemir can be used once daily in many patients with diabetes. Together with patient-friendly injection devices and dose adjustments, it provides a treatment option with the potential to lower the key barriers of adherence to insulin therapy in type 2 diabetes. Recent guidelines for treatment of type 2 diabetes suggest starting intensive therapy of hyperglycemia at an early stage of diabetes and recommend therapeutic options that provide the possibility of reaching HbA_1c goals individually, with a low risk of hypoglycemia or other adverse effects of treatment. The properties of insulin detemir match these requirements.

Diabetes and obesity: therapeutic targeting and risk reduction - a complex interplay

Obesity is a major risk factor for the development of diabetes and predisposes individuals to hypertension and dyslipidaemia. Together these pathologies increase the risk for cardiovascular disease (CVD), the major cause of morbidity and mortality in type 2 diabetes mellitus (T2DM). Worsening trends in obesity and T2DM raise a serious conundrum, namely, how to control blood glucose, blood pressure, and lipids when many antidiabetic agents cause weight gain and thereby exacerbate other cardiovascular risk factors associated with T2DM. Further, evidence suggests that some established antihypertensive agents may worsen glucose intolerance. Many patients who are obese, hypertensive, and/or hyperlipidaemic fail to achieve blood pressure, lipid and glycaemic goals, and this failure may in part be explained by physician reluctance to utilize complex combination regimens for fear of off-target effects. Thus, a clear need exists for clinicians to understand the risks and benefits of different pharmacologic, and indeed non-pharmacologic, options in order to maximize treatment outcomes. While intensive lifestyle modification remains an elusive gold standard, newer diabetes targets, including the incretin axis, may offer greater cardiovascular risk reduction than other antidiabetes therapies, although definitive clinical trial data are needed. The glucagon-like peptide-1 (GLP-1) receptor agonists exenatide and liraglutide and the dipeptidyl peptidase-4 (DPP-4) inhibitors sitagliptin and vildagliptin effectively lower HbA1c; exenatide and liraglutide reduce weight and blood pressure and improve lipid profiles. Sitagliptin and vildagliptin are weight neutral but also appear to improve lipid profiles. Integration of incretin therapies into the therapeutic armamentarium is a promising approach to improving outcomes in T2DM, and perhaps even in reducing complications of T2DM, such as co-morbid hypertension and dyslipidaemia. Additional long-term studies, including CVD end-point studies, will be necessary to determine the appropriate places for incretin-based therapies in treatment algorithms.

Comparison of the efficacy and safety of insulin glargine and insulin detemir with NPH insulin in children and adolescents with type 1 diabetes mellitus receiving intensive insulin therapy

OBJECTIVE

The purpose of this study was to compare the efficacy and safety of insulin glargine and detemir with NPH insulin in children and adolescents with type 1 diabetes mellitus (DM).

METHODS

Thirty four children and adolescents with type 1 DM (mean age 12.7 ± 3.4 years, diabetes duration 5.4 ± 3.0 years) were included in the study. All patients had been receiving intensive insulin therapy with insulin aspart and NPH for at least 6 months before switching from NPH to insulin glargine (Group 1, n=19) or detemir (Group 2, n=15). The medical records obtained within 6 months before and after treatment with insulin glargine and detemir were retrospectively reviewed and the data were compared in each group.

RESULTS

The mean age and duration of DM were similar in two groups (p>0.05). In both groups, switching from NPH to insulin glargine or detemir, resulted in a reduction in HbA(1c) (p0.05, for both). Patients in the detemir treated group had less increment in body mass index (BMI) SDS at the end of 6 months of therapy compared to NPH and glargine treated patients (p>0.05, for both). No side effects were noted throughout the study.

CONCLUSION

Both insulin glargine and detemir improved HbA(1c) at short-term and proved to be safe and well tolerated in children and adolescents with type 1 DM.