U-500 insulin: why, when and how to use in clinical practice

Evaluation of a Conservative Pharmacist-led U-500R Insulin Management Protocol in the Primary Care Setting

Objective

The objective of this quality assurance study is to evaluate the impact of a conservative, pharmacist-led, U-500R insulin management protocol on diabetes control (A1c) and total daily dosage requirements between August 2016 and August 2018.

Methods

This was a retrospective chart review of adult patients, aged 18 to 79, with type 2 diabetes and managed with insulin, at 2 federally qualified healthcare clinics in Denver, Colorado. To determine if our conservative pharmacist-led U-500R insulin management protocol impacted efficacy and total daily dosage requirements when converting patients from U-100 to U-500R insulin, we compared the most effective dose of U-500R (defined as the total daily dose (TDD) of U-500R insulin at A1c goal or the lowest tolerated A1c) to the baseline A1c and TDD of U-100 insulin at time of conversion.

Results

Following conversion of U-100 to U-500R insulin, patients required an average of 21 fewer units of insulin with U-500R than U-100 and achieved an average A1c of 7.2% which reflected a reduction of 3.5 points from baseline. Five patients (62.5%) achieved A1c goal per ADA guidelines, and all patients achieved at least a 1.7 point reduction in A1c, with 1 patient achieving a 6.7 point reduction. Two patients (25%) were still in the process of U-500R titration at the time of data collection, and 1 patient (12.5%) did not achieve goal A1c while under pharmacy management at these clinics. Four of the five patients who achieved A1c goal did so with an overall reduction in total daily insulin dose (average of 57.5 units less than original U-100 dose) resulting in an average A1c decrease of 3.6 points.

Concentrated insulins in current clinical practice

New concentrated insulins (exceeding 100 units/mL) and dedicated devices have recently become available, offering new treatment options for people with diabetes, for basal and prandial insulin supplementation. The concentrated insulin formulations range from 2-fold concentration (insulin lispro 200 units/mL) with rapid-acting prandial action to 5-fold concentration (human regular insulin, 500 units/mL) with basal and short-acting prandial actions. Long-acting basal insulins include degludec 200 units/mL and glargine 300 units/mL. Concentrated insulins have been developed with the goal of easing insulin therapy by reducing the volume and number of injections and in some cases making use of altered pharmacokinetic and pharmacodynamic properties. This review summarizes the unique characteristics of each concentrated insulin to help healthcare providers and people with diabetes understand how to best use them.

A retrospective review of insulin requirements in patients using U-500 insulin hospitalized to a Veterans Affairs Hospital

AIMS

The aim of this study was to compare the changes in the total daily dose (TDD) of insulin of patients on U-500 insulin; before hospitalization, during hospitalization and six weeks after discharge.

METHODS

A retrospective chart review of veterans with type 2 diabetes receiving U-500 insulin in the ambulatory setting and who were admitted between 2012 and 2015 was performed. During hospitalization, patients were transitioned to receive U-100 insulin (detemir or glargine for basal and aspart for bolus). Paired t-tests were conducted to compare TDD of insulin during hospitalization to prior to admission and at six week of follow-up.

RESULTS

The average hemoglobin A1_c at the time of hospital admission was 8.3±1.5% (n=20). The average TDD of insulin during hospitalization (124±67units) was significantly less than prior to admission (295±123units) and at six week follow-up (310±105units). The average glucose during hospitalization was 180±36mg/dL. Hypoglycemia was less than 0.5%.

CONCLUSION

We showed that patients received significantly less total daily insulin while hospitalized compared to their insulin doses in the ambulatory setting, and we demonstrate that patients receiving U-500 insulin can be safely transitioned to U-100 insulin while hospitalized, with minimal hypoglycemia.

Patient-reported outcomes in transition from high-dose U-100 insulin to human regular U-500 insulin in severely insulin-resistant patients with type 2 diabetes: analysis of a randomized clinical trial

Background

Initiation and titration of human regular U-500 insulin (U-500R) with a dosing algorithm of either thrice daily (TID) or twice daily (BID) improved glycemic control with fewer injections in patients with type 2 diabetes treated with high-dose, high-volume U-100 insulin. The objective of this analysis was to compare patient-reported outcomes between U-500R TID and BID treatment groups in this titration-to-target randomized, clinical trial.

Methods

In this 24-week, open-label, parallel trial, 325 patients were randomized to TID (n = 162) or BID (n = 163) U-500R after a 4-week lead-in period (screening). The Treatment Related Impact Measure-Diabetes (TRIM-D) and EQ-5D-5L questionnaires were administered at screening, baseline/randomization, and endpoint (24 weeks). The Visual Analog Scale-Injection Site Pain (VAS-ISP) was assessed at baseline/randomization, 12 weeks, and endpoint.

Results

The TRIM-D showed statistically significant improvements in overall scores from baseline to endpoint for both BID and TID groups, most domains in the TID group, and all domains in the BID group. The BID group achieved better scores than the TID patients in overall and in treatment burden, daily life, and compliance domains (p < .05). EQ-5D-5L index scores showed no statistically significant differences for TID and BID groups (and no differences between TID and BID groups) from baseline to endpoint. VAS-ISP scores improved for both treatment groups (−5.60 TID; −6.47 BID; p < .05 for both) from baseline to endpoint.

Conclusions

U500 can be successfully titrated for improved glycemic control using BID and TID regimens with diabetes-specific Patient-Reported Outcomes showing improvements in both arms; however, BID had better scores than TID in overall, treatment burden, daily life, and compliance domains.

Trial registration

These secondary analyses are based on the study first received January 22, 2013 and reported in Clinical Trial Registry No.: NCT01774968.

Treatment of Diabetic Ketoacidosis With Intravenous U-500 Insulin in a Patient With Rabson-Mendenhall Syndrome: A Case Report

Rabson-Mendenhall syndrome is a rare genetic disorder resulting from mutations in the insulin receptor and is associated with high degrees of insulin resistance. These patients are prone to complications secondary to their hyperglycemia including diabetic ketoacidosis (DKA). We report the case of a 19-year-old male with Rabson-Mendenhall syndrome presenting with DKA who required doses of up to 500 U/h (10.6 U/kg/h) of insulin. The patient's insulin infusion was originally compounded with U-100 regular insulin, although to minimize volume, the product was compounded with U-500 insulin. The DKA eventually resolved requiring infusion rates ranging from 400 to 500 U/h. Although numerous opportunities for medication errors exist with the use of U-500 insulin, this case outlines the safe use of concentrated intravenous insulin when clinically indicated for patients requiring extremely high doses of insulin to control blood glucose.

Pharmacologic Treatment of Type 2 Diabetes

Objective: To review the oral and injectable pharmacologic treatment options for type 2 diabetes. Data Sources: A literature search was conducted using PubMed electronic database for studies published in English between 1993 and September 2014. Search terms included diabetes mellitus, type 2 diabetes, and the individual name for each antidiabetic medication reviewed. In addition, manual searches were performed for cross-references from publications. Package inserts, United States Food and Drug Administration (FDA) Web site, Institute for Safe Medication Practices Web site, American Diabetes Association Web site and scientific session poster presentations, and individual drug company Web pages were also reviewed. Study Selection and Data Extraction: This review focused on information elucidated over the past 10 years to assist prescribers in choosing optimal therapy based on individual patient characteristics. Studies leading to the approval of or raising safety concerns for the antidiabetic medications reviewed in this article were included. Data Synthesis: In the past 10 years, there have been 4 novel oral antidiabetic medication classes and 10 new injectable agents and insulin products approved by the FDA for the treatment of type 2 diabetes as well as new information regarding the safety and use of several older antidiabetic medication classes. The distinctions were reviewed for each individual agent, and a comparison was completed if there was more than one agent in a particular therapeutic class. Using current information available, select investigational agents in phase III trials or with a pending new drug application were highlighted. Conclusion: There are now 9 distinct oral pharmacologic classes and a variety of insulin and noninsulin injectable medications available for the treatment of type 2 diabetes. Metformin remains the first-line treatment option for most patients. When considering options for alternative or additional treatment, prescribers must weigh the benefits and risks using individual patient characteristics.

Initiation of human regular U-500 insulin use is associated with improved glycemic control: a real-world US cohort study

AIM

Describe the characteristics of patients initiating human regular U-500 insulin (U-500R) and their subsequent glycemic control in a real-world setting.

METHODS

US Humedica electronic health record system data (July 2007-September 2011) were used to identify patients with diabetes aged ≥18 years with ≥1 records for U-500R prescriptions, 6 months of preindex data, 12 months following first use of U-500R, and at least one glycated hemoglobin (HbA1c) value in both preindex and postindex periods. Paired t tests were used to measure the change in HbA1c from preindex to postindex periods (last or most recent values) and hypoglycemia.

RESULTS

Among patients initiating U-500R (N=445), 96.9% had type 2 diabetes with mean age 57 years and mean body mass index 40.4 kg/m(2). Postindex prescriptions were written for U-500R alone (47.0%, group A) and concomitant U-500R/U-100 insulins (53.0%, group B). Concomitant oral antihyperglycemic agents (AHAs) and non-insulin injectable AHAs were used by 43.4% and 14.6% of patients, respectively. Following initiation of U-500R, mean HbA1c improved 0.68% in all patients (p<0.0001 compared with baseline), but the decrease in HbA1c did not differ significantly between groups (A: 0.78%; B: 0.60%). Overall, hypoglycemic events, largely captured in the outpatient setting, increased in incidence from 6.7% to 11.9% (p≤0.0001) and from 0.23 to 0.39 events/patient/year, an increase of 0.16 (p=0.003), from preindex to postindex.

CONCLUSIONS

This real-world outcomes analysis demonstrates that U-500R initiation is associated with a clinically meaningful improvement in glycemic control over the subsequent 12-month period with modest increase in incidence and rate of hypoglycemia.

A practical guide to concentrated insulin for pharmacists

PURPOSE

Insulin improves glycemic control in several ways, for example, by stimulating glucose uptake in the muscle and inhibiting hepatic glucose production. It has other mechanisms of action for correcting the abnormal metabolism of proteins, fats, and carbohydrates. The formulation of concentrated insulin (U-500) is a higher potency of insulin than the U-100 regular formulation. It is indicated for children and adults with type 1 and type 2 diabetes who have not achieved adequate glycemic control with exercise and proper dietary habits. However, the unique characteristics of concentrated insulin require that a patient be educated on its use. This article provides a practical guide for pharmacists on the use of concentrated insulin in both inpatient and outpatient settings and highlights specific concerns and management strategies.

CONCLUSION

Concentrated insulin works in the same mechanism as U-100 insulin formulations for treating type 1 and type 2 diabetes. Pharmacists are knowledgeable about managing the disease and can identify patients who will benefit with treatment of concentrated insulin. They can provide recommendations to prevent and resolve situations, such as dosing errors, which arise in patients on concentrated insulin and can educate patients and health care professionals on dosing conversions and titration.

Application of PK/PD modeling and simulation to dosing regimen optimization of high-dose human regular U-500 insulin

Pharmacokinetic/pharmacodynamic (PK/PD) studies of human regular U-500 insulin (U-500R) at high doses commonly used in clinical practice (>100 units) have not been performed. The current analysis applied PK/PD modeling/simulation to fit the data and simulate single-dose and steady-state PK/PD of U-500R high-dose regimens. Data from 3 single-dose euglycemic clamp studies in healthy obese and normal-weight patients, and normal-weight patients with type 1 diabetes were used to build the model. The model was sequential (PK inputs fed into PD component). PK was described using a 1-compartment model with first-order absorption and elimination. The model estimated separate absorption rate constants for U-500R and human regular U-100 insulin. The PD component used an effect compartment model, parameterized in terms of maximum pharmacologic effect (E(max)) and concentration to achieve 50% of E(max). The model described the data well. Steady-state PK for once-daily (QD), twice-daily (BID), or thrice-daily (TID) administration appeared to be reached 24 hours after the first dose. At steady-state, QD dosing showed the greatest fluctuations in PK/PD. BID dosing showed a gradual increase in insulin action with each dose and a fairly stable basal insulin effect. For TID dosing, activity was maintained throughout the dosing interval. PK/PD modeling/simulation of high U-500R doses supports BID or TID administration with an extended duration of activity relative to QD. TID dosing may provide slightly better full-day insulin effect. Additional PK/PD studies and randomized controlled trials of U-500R are needed to validate model predictions in patients with insulin-resistant diabetes requiring high-dose insulin.

Inpatient management of women with gestational and pregestational diabetes in pregnancy

For women with type 1 diabetes (T1DM), type 2 diabetes (T2DM), and gestational diabetes (GDM), poor maternal glycemic control can significantly increase maternal and fetal risk for adverse outcomes. Outpatient medical and nutrition therapy is recommended for all women with diabetes in order to facilitate euglycemia during the antepartum period. Despite intensive outpatient therapy, women with diabetes often require inpatient diabetes management prior to delivery as maternal hyperglycemia can significantly increase neonatal risk of hypoglycemia. Consensus guidelines recommend maternal glucose range of 80-110 mg/dL in labor. The most optimal inpatient strategies for the prevention of hyperglycemia and hypoglycemia proximate to delivery remain unclear and will depend upon factors such as maternal diabetes diagnosis, her baseline insulin resistance, duration and route of delivery etc. Low dose intravenous insulin and dextrose protocols are necessary to achieve optimal predelivery glycemic control for women with T1DM and T2DM. For most with GDM however, euglycemia can be maintained without intravenous insulin. Women treated with a subcutaneous insulin pump during the antepartum period represent a unique challenge to labor and delivery staff. Strategies for self-managed subcutaneous insulin infusion (CSII) use prior to delivery require intensive education and coordination of care with the labor team in order to maintain patient safety. Hospitalization is recommended for most women with diabetes prior to delivery and in the postpartum period despite appropriate outpatient glycemic control. Women with poorly controlled diabetes in any trimester have an increased baseline maternal and fetal risk for adverse outcomes. Common indications for antepartum hospitalization of these women include failed outpatient therapy and/or diabetic ketoacidosis (DKA). Inpatient management of DKA is a significant cause of maternal and fetal morbidity and remains a common indication for hospitalization of the pregnant woman with diabetes. Changes in maternal physiology increase insulin resistance and the risk for DKA. A systematic approach to its management will be reviewed.

The use of U-500 regular insulin in the management of patients with obesity and insulin resistance

The rise in prevalence of obesity and diabetes has created a challenge in managing increasing numbers of patients who require high doses of insulin. This article reviews the published literature on the properties of U-500 insulin and its use in clinical practice. U-500 insulin is likely to have a longer time to peak effect and a longer duration of action than similar doses of U-100 insulin. Evidence for its use in clinical practice rests on retrospective case series, which suggests that the use of U-500 insulin either by multiple daily injections or a continuous subcutaneous insulin infusion is effective in improving glycaemic control. To prevent insulin dosing and administration errors, great care must be taken in providing staff and patient education, and in developing policies for the management of patients on U-500 insulin who are admitted to hospital.

Low-volume insulin degludec 200 units/ml once daily improves glycemic control similarly to insulin glargine with a low risk of hypoglycemia in insulin-naive patients with type 2 diabetes: a 26-week, randomized, controlled, multinational, treat-to-target trial: the BEGIN LOW VOLUME trial

OBJECTIVE

The 200 units/mL formulation of insulin degludec (IDeg 200 units/mL) contains equal units of insulin in half the volume compared with the 100 units/mL formulation. We compared the efficacy and safety of IDeg 200 units/mL once daily with 100 units/mL insulin glargine (IGlar) in insulin-naïve subjects with type 2 diabetes (T2DM) inadequately controlled with oral antidiabetic drugs.

RESEARCH DESIGN AND METHODS

In this 26-week, open-label, treat-to-target trial, subjects (n = 457; mean HbA1c 8.3% [67 mmol/mol], BMI 32.4 kg/m(2), and fasting plasma glucose [FPG] 9.6 mmol/L [173.2 mg/dL]) were randomized to IDeg 200 units/mL or IGlar, both given once daily in combination with metformin with or without a dipeptidyl peptidase-4 inhibitor. Basal insulin was initiated at 10 units/day and titrated weekly to an FPG target of <5 mmol/L (<90 mg/dL) according to mean prebreakfast self-measured blood glucose values from the preceding 3 days.

RESULTS

By 26 weeks, IDeg reduced HbA1c by 1.30% and was not inferior to IGlar. Mean observed FPG reductions were significantly greater with IDeg than IGlar (-3.7 vs. -3.4 mmol/L [-67 vs. -61 mg/dL]; estimated treatment difference: -0.42 [95% CI -0.78 to -0.06], P = 0.02). Despite this difference, rates of overall confirmed hypoglycemia were not higher with IDeg than with IGlar (1.22 and 1.42 episodes/patient-year, respectively), as were rates of nocturnal confirmed hypoglycemia (0.18 and 0.28 episodes/patient-year, respectively). Mean daily basal insulin dose was significantly lower by 11% with IDeg 200 units/mL compared with IGlar. IDeg was well-tolerated, and the rate of treatment-emergent adverse events was similar across groups.

CONCLUSIONS

In this treat-to-target trial in insulin-naïve patients with T2DM, IDeg 200 units/mL improved glycemic control similarly to IGlar with a low risk of hypoglycemia.

U-500R and aspart insulin for the treatment of severe insulin resistance in pregnancy associated with pregestational diabetes

Severe insulin resistance as a complication of diabetes in pregnancy is seen with increasing frequency. Treatment with large doses of insulin (>300 units perday) can be practically difficult. A woman with preexisting Type 2 diabetes mellitus and poor glycemic control presented in early pregnancy requiring over 1000 units of insulin daily. She was transitioned to subcutaneous U-500 (concentrated regular insulin) in combination with a rapid-acting insulin analog achieving good glycemic control and good maternal and fetal outcomes. U-500R insulin in conjunction with a rapid-acting insulin analog can be used safely in early pregnancy to improve glycemic control in severe insulin resistance due to pregestational diabetes.

Cost, healthcare resource utilization, and adherence of individuals with diabetes using U-500 or U-100 insulin: a retrospective database analysis

OBJECTIVE

To describe costs, healthcare resource utilization, and adherence of US patients receiving human regular U-500 insulin (U-500R), compared to patients receiving high-dose (>200 units/day) U-100 insulins (U-100) by subcutaneous injection for the treatment of diabetes.

METHODS

A retrospective analysis of data from Thomson Reuters MarketScan Research Databases (7/1/2008 to 12/31/2010). Difference-in-differences analyses were conducted on cost (medical, pharmacy, and overall costs) and on healthcare resource utilization variables (overall, diabetes-related, and non-diabetes-related medical visits). Adherence rates to the index insulins were assessed by proportion of days covered (PDC).

RESULTS

Seven hundred and eleven (19%) patients in the U-500R cohort and 1508 (6%) patients in the U-100 cohort met selection criteria. Propensity score matching resulted in 684 matched pairs. Mean change in annualized pharmacy costs was in favor of the U-500R vs the U-100 cohort (-$1258 vs $3345, a difference of -$4603, p < 0.0001). Mean overall cost increase in the U-500R vs the U-100 cohort was also lower ($1999 vs $9104, a difference of -$7105, p = 0.005). The proportion of patients with at least one coded hypoglycemic event during the 12-month post-index period was higher in the U-500R vs the U-100 cohort (17.1% vs 11.7%, p < 0.005), but neither hypoglycemia rate (2.73 vs 2.90 events per person) nor hypoglycemia-specific costs (mean $1669 vs $1543) were significantly different. No significant differences were noted between cohorts for change (post-pre) in any resource utilization category. PDC was greater in the U-500R vs the U-100 cohort (65.2% vs 39.5%, p < 0.0001).

LIMITATIONS

Claims data are not as accurate as empirical evaluation by a clinician. Glycemic control data were not available for this analysis.

CONCLUSIONS

In patients requiring high-dose insulin, treatment with U-500R vs high-dose U-100 insulins is associated with significant decreases in pharmacy and overall costs, slightly higher hypoglycemia incidence, no difference in hypoglycemia-specific costs or in resource utilization, and better adherence.

Evolution of insulin development: focus on key parameters

INTRODUCTION

Although insulin products and treatment strategies have improved significantly, clinical challenges still exist. Meeting glycemic goals while minimizing glucose variability and hypoglycemia is of utmost importance when considering existing insulin therapies and designing investigational insulin treatments.

METHODS

A PubMed search identified relevant, peer-reviewed articles related to the evolution of insulin development for this nonsystematic review. Search terms included "animal insulin," "synthetic insulin," "regular human insulin," "insulin lispro," "insulin aspart," "insulin glulisine," "insulin glargine," "insulin detemir," "insulin degludec," "biphasic human insulin," "insulin premixes," "ultra-long acting," "oral insulin," and "inhaled insulin."

RESULTS

While the discovery of animal insulin significantly decreased mortality rates from diabetes, issues with availability and large variability between batches led to difficulty in determining proper doses and, subsequently, challenges in achieving glycemic control and avoiding hypoglycemia. The development of synthetic insulin created a more readily available supply, but hypoglycemia still persisted. Recombinant DNA technology solved insulin production problems and allowed for the development of better retarding agents, but pharmacokinetic/pharmacodynamic profiles still did not mimic natural insulin. Insulin premixes offered improved glycemic control, decreased intrapatient variability versus self-mixing, and required fewer injections per day; however, patient adherence remained a problem due to the need to inject 30-60 minutes before a meal for optimal control. This prompted the development of rapid-acting insulin analogs that could be injected right before a meal and long-acting insulin analogs with flatter time-action profiles.

CONCLUSION

Despite advances in insulin development, a need to provide more physiologic basal insulin coverage and reduce hypoglycemic risk in patients with diabetes remains. Newer insulin analogs and more convenient routes of insulin delivery have shown promising safety and efficacy results. Many patients with diabetes have not reached glycemic goals on currently available insulins. Additional studies are necessary to tailor optimal insulin delivery strategies to specific subsets of diabetes patients.

U-500 insulin as a component of basal bolus insulin therapy in type 2 diabetes

BACKGROUND

Changes in hemoglobin A1c (A1C), weight, and total daily insulin dose (TDD) were investigated following initiation of insulin U-500 (U500) alone or as part of a basal/bolus insulin (BBI) regimen.

SUBJECTS AND METHODS

Records of patients with type 2 diabetes who were prescribed U500 were retrospectively reviewed. Logistic regression analysis was used to investigate relationships between changes in A1C and use of U500 alone or as BBI.

RESULTS

Twelve patients were identified as using U500 alone (n=2) or in combination with long-acting (LAI) (n=7) or rapid-acting (RAI) (n=3) insulin. Reductions in A1C (9.5% at baseline vs. 7.7% at 6-9 months, P<0.0001) and increases in weight (128.8±32.7 vs. 131.5±31.3 kg, P<0.014) and TDD (260±111 to 333±106 units/day, P<0.0002) were observed. Concurrent use of LAI or RAI with U500 did not predict improvements in A1C.

CONCLUSIONS

U500 resulted in improvements in A1C and weight gain and increased TDD when used alone or as part of combination insulin therapy. Further investigations to define the optimal use of U500 are recommended.

A 16-week open-label, multicenter pilot study assessing insulin pump therapy in patients with type 2 diabetes suboptimally controlled with multiple daily injections

BACKGROUND

We assessed the efficacy, safety, and patient-reported outcomes (PROs) of insulin pump therapy in patients with type 2 diabetes mellitus (T2DM) who were suboptimally controlled with a multiple daily injection (MDI) regimen.

METHODS

In this subanalysis of a 16-week multicenter study, 21 insulin-pump-naïve patients [age 57 ± 13 years, hemoglobin A1c (A1C) 8.4 ± 1.0%, body weight 98 ± 20 kg, total daily insulin dose 99 ± 65 U, mean ± standard deviation] treated at baseline with MDI therapy with or without oral antidiabetic agents discontinued all diabetes medications except metformin and initiated insulin pump therapy. Insulin was titrated to achieve the best possible glycemic control with the simplest possible dosing regimen. Outcome measures included A1C, fasting and postprandial glucose, body weight, incidence of hypoglycemia, and PROs.

RESULTS

Glycemic control improved significantly after 16 weeks: A1C 7.3 ± 1.0% (-1.1 ± 1.2%, p < .001), fasting glucose 133 ± 33 mg/dl (-32 ± 74 mg/dl, p < .005), and postprandial glucose 153 ± 35 mg/dl (-38 ± 46 mg/dl, p < .001). At week 16, the mean daily basal, bolus, and total insulin doses were 66 ± 36, 56 ± 40, and 122 ± 72 U (1.2 U/kg), respectively, and 90% of patients were treated with two or fewer daily basal rates. Body weight increased by 2.8 ± 2.6 kg (p < .001). Mild hypoglycemia was experienced by 81% of patients at least once during the course of the study with no episodes of severe hypoglycemia. There were significant improvements in PRO measures.

CONCLUSIONS

Insulin pump therapy using a relatively simple dosing regimen safely improved glucose control and PROs in patients with T2DM who were unable to achieve glycemic targets with MDI therapy. Controlled trials are needed to further assess the clinical benefits and cost-effectiveness of insulin pumps in this patient population.

Extreme insulin resistance: indications and approaches to the use of U-500 insulin in type 2 diabetes mellitus

The use of U-500 insulin in the management of highly insulin resistant diabetic patients is growing. There are a number of reports that have noted the effects of U-500 insulin using multiple daily injections or continuous subcutaneous insulin infusion on hemoglobin A(1c), weight, and total daily insulin dosage. The effect of U-500 insulin use on glycemic control, changes in body weight, total daily insulin dosage, incidence of hypoglycemia, and effect on lipid levels and blood pressure as well as patient satisfaction and quality of life will be reviewed. In addition, this article will delineate algorithms of U-500 use, compare multiple daily injections or continuous subcutaneous insulin infusion, and discuss U-500 insulin pharmacokinetics.

Clinical approach to the patient with diabetes mellitus and very high insulin requirements

A number of patients with diabetes require very high (> 2 Ukg⁻¹ day⁻¹), or extremely high (> 3 Ukg⁻¹ day⁻¹), insulin doses for the management of their hyperglycemia. Unfortunately, many of the physicians who treat these patients limit themselves to prescribing ever higher doses of insulin, without questioning why. Furthermore, when the insulin requirements get to be extreme, demanding an explanation, clinicians are frequently lost in a sea of literature where there is not a single paper dealing with this problem systematically. A systematic approach to the evaluation of these patients is necessary to facilitate an appropriate diagnosis, select the most reasonable therapy, and hopefully improve the long-term outcome of these patients. This manuscript intends to provide the clinician with a review of the literature pertinent for the differential diagnosis, work-up, and management of these patients. We will review the definitions of insulin sensitivity during normality, the various degrees or categories of insulin resistance, and the expected insulin requirements during each of these states. Subsequently, we propose a simple alphabetic mnemonic approach to help remember the differential diagnosis, and a clinical algorithm to help guide the work-up of these patients. Lastly, we briefly discuss general management considerations in these conditions.

Insulin pump therapy in patients with type 2 diabetes safely improved glycemic control using a simple insulin dosing regimen

BACKGROUND

This study assessed insulin dose and dosing patterns required to optimize glycemic control with an insulin pump in patients with type 2 diabetes.

METHODS

In this 16-week, open-label, multicenter, pilot study, 56 insulin pump-naive patients treated at baseline with two or more oral antidiabetes agents (OADs), basal insulin with or without OADs, or basal-bolus insulin with or without OADs discontinued all diabetes medications except metformin and initiated insulin pump therapy. Insulin doses were adjusted to optimize glycemic control with the simplest possible insulin regimen. Outcomes included total daily insulin dose, daily basal and bolus insulin doses, number of daily basal rates, hemoglobin A1C, fasting and postprandial glucose, patient-reported outcomes and rate of hypoglycemia.

RESULTS

After 16 weeks of pump therapy, the mean +/- SD total daily insulin dose was 95 +/- 59 U. The percentage of the total daily insulin dose used as basal and as bolus delivery was 55% and 45%, respectively. Eighty-eight percent of patients were treated with two or fewer daily basal rates. Mean A1C was lowered by 1.2 +/- 1.2% (P < 0.001), and there was no severe hypoglycemia. Mean change in body weight was +1.9 +/- 3.3 kg (P < 0.001). Overall treatment preference improved with pump therapy compared to baseline.

CONCLUSIONS

Insulin pump therapy using a simple dosing regimen significantly improved glycemic control in patients with type 2 diabetes. Patients experienced limited weight gain, there was no severe hypoglycemia, and overall treatment preference improved significantly.

Clinical efficacy and patient satisfaction with U-500 insulin use

AIMS

The prevalence of highly insulin-resistant diabetes is increasing and treatment requires the use of very high doses of insulin. This study was performed to analyze efficacy and patient satisfaction with use of U-500 concentrated insulin.

METHODS

The medical records of 40 patients using U-500 insulin for at least 3 months were reviewed. A quality of life questionnaire was administered 6 or more months after U-500 was initiated. Effects of U-500 use on HbA1c, weight, total daily insulin use, hypoglycemia, and patient satisfaction were measured.

RESULTS

Patients had uncontrolled diabetes for 3 years prior to U-500 initiation despite insulin titration. Subjects required continued insulin titration to attain glycemic control even after U-500 initiation, but HbA1c decreased by 1.5% within 3 months. Subjects gained weight with insulin titration. Hypoglycemic symptoms increased early after transition to U-500 insulin, but patients reported fewer hypoglycemic episodes on the quality of life questionnaire. Patient satisfaction with diabetes care and control was significantly improved following transition to U-500 insulin.

CONCLUSIONS

Use of U-500 insulin assists with attaining glycemic control in highly insulin-resistant subjects, but at the cost of weight gain and increased insulin doses. However, patient satisfaction is improved with U-500 insulin use.

High-dose insulin therapy: is it time for U-500 insulin?

OBJECTIVE

To provide an overview of U-500 regular insulin action, review published clinical studies with U-500 regular insulin, and offer guidance to practicing endocrinologists for identifying patients for whom U-500 regular insulin may be appropriate.

METHODS

This review has been produced through a synthesis of relevant published literature compiled via a literature search (MEDLINE search of the English-language literature published between January 1969, and July 2008, related to U-500, insulin resistance, concentrated insulin, high-dose insulin, insulin pharmacokinetics, and diabetes management) and the authors' collective clinical experience.

RESULTS

The obesity epidemic is contributing to an increase in the prevalence of type 2 diabetes, as well as to increasing insulin requirements in insulin-treated patients. Many of these patients exhibit severe insulin resistance, manifested by daily insulin requirements of 200 units or greater or more than 2 units/kg. Delivering an appropriate insulin volume to these patients can be difficult and inconvenient and may be best accomplished with U-500 regular insulin by multiple daily injections or with continuous subcutaneous insulin infusion, rather than with standard U-100 insulin. Implementation of U-500 regular insulin in patients previously on other insulin formulations is described with a treatment algorithm covering dosage requirements ranging from 150 to more than 600 units per day on the basis of the authors' experience.

CONCLUSIONS

Regimen conversion of appropriately selected patients from high-dose, U-100 insulin to U-500 regular insulin therapy on the basis of the recommendations presented in this article may potentially result in improved glycemic control and lower cost.