Impact of injection sites for soluble insulin on glycaemic control in type 1 (insulin-dependent) diabetic patients treated with a multiple insulin injection regimen

Clinical Considerations for Insulin Therapy in Older Adults with Type 1 Diabetes

Type 1 diabetes represents an autoimmune condition with a strong inherited background, and its incidence is increasing worldwide. About 25% of such cases are diagnosed in adulthood, some even as late as the ninth decade of life. The number of older adults with type 1 diabetes is increasing due to improvements in care and decreased mortality rate. However, there is a lack of clinical trials in people older than 70 years of age with type 1 diabetes complicated with comorbidities, frailty, and dependency. The management of type 1 diabetes and the goals of therapy should be individualized based on the patient's health status and life expectancy. In healthier older adults, insulin treatment regimens (multiple daily insulin injections or insulin pump therapy) that approximate the normal physiology of insulin secretion should be used to achieve lower glycemic goals, while reducing the risk of hypoglycemia with frequent glucose monitoring (preferably using continuous glucose monitoring systems). For frail individuals with poor health, simpler insulin regimens and less stringent glycemic targets would be more appropriate. Poor cognition, vision and hearing, impaired mobility, depression, and chronic pain can interfere with complex insulin regimens. In these individuals, the principal goals of therapy are to reduce the acute effects of hyperglycemia, minimize hypoglycemia risk, and optimize quality of life. The newer insulin preparations and technological advances in insulin delivery and blood glucose monitoring have enhanced the management of type 1 diabetes in all age groups.

Systematic Review of Device Parameters and Design of Studies Bridging Biologic-Device Combination Products Using Prefilled Syringes and Autoinjectors

Biologic-device combination products using prefilled syringes (PFSs) and autoinjectors (AIs) are popular for biological products administered subcutaneously. Pharmacokinetic (PK) comparability studies commonly provide the scientific data to support introduction of AI presentations via bridging with PFS. A survey of biological products approved by FDA's Center for Drug Evaluation and Research identified 17 biologics license applications (BLAs) with both PFS and AI presentations for subcutaneous (SC) administration, including 16 approved on February 1, 2018, and one with AI presentation under review. A systematic review on the device parameters and the PK comparability studies bridging the two presentations was conducted. Subsequently, whether device parameters or the PK study design may have influenced the PK comparability study results was evaluated. The reported device parameters for AI and PFS are generally consistent across BLAs, whereas the approach to assess PK comparability varied, including the study design. Most PK comparability studies met bioequivalence (BE) criteria. Upon inspection of the studies that did not meet BE criteria, injection depth of AI and the injection site for either AI or PFS were identified as potential influencing factors to the outcome of PK comparability study. This study represents an initial attempt to identify the potential influencing factors on device bridging, including the characteristics of the device and the clinical pharmacology study. These findings may inform the combination product development strategy, specifically design considerations for device and PK comparability studies.

Factors Affecting the Absorption of Subcutaneously Administered Insulin: Effect on Variability

Variability in the effect of subcutaneously administered insulin represents a major challenge in insulin therapy where precise dosing is required in order to achieve targeted glucose levels. Since this variability is largely influenced by the absorption of insulin, a deeper understanding of the factors affecting the absorption of insulin from the subcutaneous tissue is necessary in order to improve glycaemic control and the long-term prognosis in people with diabetes. These factors can be related to either the insulin preparation, the injection site/patient, or the injection technique. This review highlights the factors affecting insulin absorption with special attention on the physiological factors at the injection site. In addition, it also provides a detailed description of the insulin absorption process and the various modifications to this process that have been utilized by the different insulin preparations available.

Indian Injection Technique Study: Population Characteristics and Injection Practices

INTRODUCTION

It was estimated that 3.2 million Indians with diabetes injected insulin in 2010, but little is known about the techniques used.

METHODS

In 2015 we conducted an injection technique questionnaire (ITQ) survey throughout India involving 1011 patients. Indian values were compared with those from 41 other countries participating in the ITQ, known here as rest of world (ROW).

RESULTS

Mean HbA1c was 8.6. BMI values in India were 1.5-3 units lower than in ROW depending on patient group, meaning the risk of intramuscular (IM) injections is high in India. The mean total daily dose (TDD) of insulin was lower in every category of Indian patient than in ROW, perhaps reflecting the lower BMI. Needle reuse, whether with pens or syringes, is much higher in India than ROW and so is the number of times the needle is used. The majority (56.8%) of Indian insulin users performed only 2 injections/day as opposed to ROW where 45% of patients performed at least 4 injections/day. Indian patients inject insulin in the thighs more often than patients in ROW, a site where IM injections are more risky. Many patients do not have proper access to sharps containers or have other risk factors that could lead to blood-borne pathogen spread. More than 60% of used sharps in India go into the rubbish, with nearly 12% not even having the minimum protection of a cap.

DISCUSSION

The shortest needles are very common in India; however, the level of needle reuse is high. Multiple daily injections therapy is not as common in India as ROW. More focus needs to be given to dwell times under the skin, reconstitution of cloudy insulins, skinfolds, and safe sharps disposal.

New Insulin Delivery Recommendations

Many primary care professionals manage injection or infusion therapies in patients with diabetes. Few published guidelines have been available to help such professionals and their patients manage these therapies. Herein, we present new, practical, and comprehensive recommendations for diabetes injections and infusions. These recommendations were informed by a large international survey of current practice and were written and vetted by 183 diabetes experts from 54 countries at the Forum for Injection Technique and Therapy: Expert Recommendations (FITTER) workshop held in Rome, Italy, in 2015. Recommendations are organized around the themes of anatomy, physiology, pathology, psychology, and technology. Key among the recommendations are that the shortest needles (currently the 4-mm pen and 6-mm syringe needles) are safe, effective, and less painful and should be the first-line choice in all patient categories; intramuscular injections should be avoided, especially with long-acting insulins, because severe hypoglycemia may result; lipohypertrophy is a frequent complication of therapy that distorts insulin absorption, and, therefore, injections and infusions should not be given into these lesions and correct site rotation will help prevent them; effective long-term therapy with insulin is critically dependent on addressing psychological hurdles upstream, even before insulin has been started; inappropriate disposal of used sharps poses a risk of infection with blood-borne pathogens; and mitigation is possible with proper training, effective disposal strategies, and the use of safety devices. Adherence to these new recommendations should lead to more effective therapies, improved outcomes, and lower costs for patients with diabetes.

Worldwide Injection Technique Questionnaire Study: Population Parameters and Injection Practices

From February 1, 2014, through June 30, 2015, 13,289 insulin-injecting patients from 423 centers in 42 countries took part in one of the largest surveys ever performed in diabetes. The goal was to assess patient characteristics, as well as historical and practical aspects of their injection technique. Results show that 4- and 8-mm needle lengths are each used by nearly 30% of patients and 5- and 6-mm needles each by approximately 20%. Higher consumption of insulin (as measured by total daily dose) is associated with having lipohypertrophy (LH), injecting into LH, leakage from the injection site, and failing to reconstitute cloudy insulin. Glycated hemoglobin values are, on average, 0.5% higher in patients with LH and are significantly higher with incorrect rotation of sites and with needle reuse. Glycated hemoglobin values are lower in patients who distribute their injections over larger injection areas and whose sites are inspected routinely. The frequencies of unexpected hypoglycemia and glucose variability are significantly higher in those with LH, those injecting into LH, those who incorrectly rotate sites, and those who reuse needles. Needles associated with diabetes treatment are the most commonly used medical sharps in the world. However, correct disposal of sharps after use is critically suboptimal. Many used sharps end up in public trash and constitute a major accidental needlestick risk. Use of these data should stimulate renewed interest in and commitment to optimizing injection practices in patients with diabetes.

Glucose-lowering effect of insulin degludec is independent of subcutaneous injection region

Background and Objectives

Patients with diabetes mellitus inject insulin in different regions of the body. This study investigated the pharmacokinetic and pharmacodynamic properties of insulin degludec (IDeg), a new-generation once-daily basal insulin with an ultra-long duration of action, after subcutaneous (SC) administration in different injection regions.

Methods

In this study, 20 healthy subjects received single SC doses of IDeg (0.4 U/kg; separated by 13–21 days) in the thigh, abdomen and deltoid in a randomised, open-label, single-centre, single-dose, complete crossover trial. Each dose was followed by a 24-h euglycaemic clamp and 120-h pharmacokinetic blood sampling. The obtained pharmacokinetic/pharmacodynamic profiles were extrapolated to steady state by simulation using a pharmacokinetic/pharmacodynamic model.

Results

Total IDeg exposure [area under the IDeg serum concentration–time curve 0–120 h after a single dose (AUC_{IDeg,0–120h,SD})] and maximum serum concentration [maximum IDeg serum concentration after a single dose (C_max,IDeg,SD)] were higher (6–7 and 23–27 %, respectively) following a single SC dose in the deltoid or abdomen, compared with the thigh, as also observed with other insulin preparations. No statistical difference was observed in these measures between deltoid and abdominal administration. No pronounced differences were observed in the glucose-lowering effect of IDeg [area under the glucose infusion rate (GIR) curve 0–24 h after a single dose (AUC_{GIR,0–24h,SD}) and maximum GIR after a single dose (GIR_max,SD)] when injected in the thigh, abdomen or deltoid (AUC_{GIR,0–24h,SD} 2,572, 2,833 and 2,960 mg/kg, respectively). Simulated mean steady-state pharmacokinetic and pharmacodynamic profiles supported a flat and stable IDeg exposure and effect regardless of injection region, with comparable total glucose-lowering effects [area under the GIR curve at steady state (AUC_GIR,τ,SS)] between the thigh, abdomen and deltoid.

Conclusions

These findings support administering IDeg SC in the thigh, upper arm or abdominal wall without affecting IDeg absorption or effect at steady state.

Electronic supplementary material

The online version of this article (doi:10.1007/s40261-014-0218-x) contains supplementary material, which is available to authorized users.

Identification and comparison of insulin pharmacokinetics injected with a new 4-mm needle vs 6- and 8-mm needles accounting for endogenous insulin and C-peptide secretion kinetics in non-diabetic adult males

Aims/Introduction

Many patients with diabetes now use 5‐, 6‐ or 8‐mm needles for insulin injection. However, it is unclear whether needle length, particularly for shorter needles, affects the pharmacokinetic properties of insulin.

Materials and Methods

This was a three‐way, randomized, cross‐over, single‐center study involving 12 healthy Japanese adult males (age 27.4 ± 4.14 years; weight 64.2 ± 5.2 kg; body fat percentage 18.2 ± 1.5%). Participants received a subcutaneous (abdomen) dose of insulin lispro (1.5 U for participants weighing 55 to <65.0 kg; 2.0 U for participants weighing 65.0 to <80.0 kg) delivered using a 32‐G × 4 mm (32G × 4), 31‐G × 8 mm (31G × 8) or 32‐G × 6 mm (32G × 6) needle with a 3–7‐day washout between doses. Pharmacokinetic parameters of exogenous insulin were identified using non‐linear least squares, where the total insulin concentration was fit to the measured plasma insulin concentration using an overall combined model that accounted for C‐peptide/insulin secretion in addition to the injected dose.

Results

Maximum concentration and area under the curve for 0 to infinity min for insulin were bioequivalent for the 32G × 4 needle relative to the 32G × 6 and the 31G × 8 needles. The time to the maximum insulin concentration was bioequivalent for the 32G × 4 needle relative to the 32G × 6 needle, but not the 31G × 8 needle.

Conclusions

The use of 4‐mm needles is unlikely to change the pharmacokinetic properties of insulin when injected subcutaneously in adults. This trial was registered with UMIN‐CTR (no. UMIN000004469).

Insulin pump therapy for pregnancy: a primer

Current knowledge and advances in insulin formulations, insulin pump technology, and blood glucose monitoring techniques have improved practitioners' ability to achieve diabetic people's blood glucose targets. Practitioners and pregnant women should bear in mind that important differences exist in glucose metabolism during pregnancy and require a different approach from non-pregnant people to avoid pregnant women's experience being adversely affected. Insulin pump therapy, if used skillfully by practitioners and their pregnant patients, can be especially beneficial for some diabetic women during their pregnancies. Women's healthcare practitioners should endeavor to be familiar with this therapy, even if they are not experts in its full complexity.

New injection recommendations for patients with diabetes

AIM

Injections administered by patients are one of the mainstays of diabetes management. Proper injection technique is vital to avoiding intramuscular injections, ensuring appropriate delivery to the subcutaneous tissues and avoiding common complications such as lipohypertrophy. Yet few formal guidelines have been published summarizing all that is known about best practice. We propose new injection guidelines which are thoroughly evidence-based, written and vetted by a large group of international injection experts.

METHODS

A systematic literature study was conducted for all peer-reviewed studies and publications which bear on injections in diabetes. An international group of experts met regularly over a two-year period to review this literature and draft the recommendations. These were then presented for review and revision to 127 experts from 27 countries at the TITAN workshop in September, 2009.

RESULTS

Of 292 articles reviewed, 157 were found to meet the criteria of relevance to the recommendations. Each recommendation was graded by the weight it should have in daily practice and by its degree of support in the medical literature. The topics covered include The Role of the Professional, Psychological Challenges, Education, Site Care, Storage, Suspension and Priming, Injecting Process, Proper Use of Pens and Syringes, Insulin analogues, Human and Pre-mixed Insulins, GLP-1 analogs, Needle Length, Skin Folds, Lipohypertrophy, Rotation, Bleeding and Bruising, Pregnancy, Safety and Disposal.

CONCLUSION

These injecting recommendations provide practical guidance and fill an important gap in diabetes management. If followed, they should help ensure comfortable, effective and largely complication-free injections.

Role Of Injection Technique In Use Of Insulin Pens: Prospective Evaluation Of A 31-Gauge, 8-Mm Insulin Pen Needle

OBJECTIVE

To evaluate the effectiveness, comfort, and ease of use of insulin pen injections with a 31-gauge, 8-mm needle.

METHODS

In 50 study subjects (24 patients with type 1 insulin-dependent diabetes and 26 insulin-using patients with type 2 diabetes), we assessed the delivery of insulin, residual insulin leakage, glycemic control, plunger depression pressure, and perceived pain associated with the B-D 31-gauge, 8-mm pen needles in comparison with the B-D conventional 30-gauge, 8-mm pen needles, while the patient used their own insulin pens (Novo or B-D). The study subjects injected their usual dose of regular and NPH insulin using the 30-gauge, 8-mm needle during the first 3 weeks of the study. This period was followed by two 3-week crossover segments of the study with either needle assigned in random sequence.

RESULTS

No statistically significant differences were noted in glycemic control or perceived pain of injection between the two needles. The interaction between the two needles and the two insulin pen brands on glycemic control was not statistically significant. Plunger depression pressure increased with the increase in the gauge of the needle and with increases in size of dose of injected insulin (P<0.01). B-D pen users reported lower plunger pressure ratings in comparison with Novo pen users (P<0.01), regardless of the needle type and dose range. Both the insulin pen type and the needle type individually had statistically significant (P<0.01) effects on the residual insulin leakage from the needle tip after injection; however, their interaction was not statistically significant. Insulin doses greater than 30 units were associated with increased leakage (P<0.01). As needle retention time decreased, residual insulin leakage from the needle tip after injection increased (P<0.01), regardless of the needle used.

CONCLUSION

The 31-gauge insulin pen needles are safe and effective for the delivery of insulin. With both 30-gauge and 31-gauge needles, attention to injection technique is essential to ensure complete delivery of insulin, particularly with administration of large doses.

Serum insulin profiles in consecutive children 2 years after the diagnosis of IDDM

We studied associations of 24-h serum insulin profiles with insulin dose, age, gender, haemoglobin A1c (HbA1c) and C-peptide values, as well as blood glucose profiles in 77 consecutive children-nine aged 2-4, 14 aged 5-8, 26 aged 9-12, and 28 aged 13-17 years--2 years after the onset of insulin-dependent diabetes mellitus (IDDM). Mean weight-based insulin doses in the four age groups were similar (0.7 +/- 0.2 U.kg-1.day-1 in all); body surface-area-based doses differed. Insulin doses correlated significantly with the 24-h mean and area-under-the-curve (AUC) values, and with mean values at 03.00 hours of serum insulin in the children aged 5-8 and 13-17 years. The mean insulin concentrations of the age groups (95% confidence intervals) increased with age [6.1 (3.8, 9.7), 7.6 (5.9, 9.8), 10.4 (8.6, 12.4), and 14.0 (11.6, 16.8) mU/l; p < 0.0002]. The 24-h mean of serum insulin together with HbA1c concentration predicted 32% of the variation of mean blood glucose concentrations. Of children aged less than 9 years, 50% had insulin values less than 5 mU/l (healthy subjects' lower reference limit), and 14% were of less than 2 mU/l (detection limit of the assay) at 03.00 hours. At 07.00 hours, 82% had insulin values of less than 5 mU/l, and 36% were of less than 2 mU/l, respectively. Some young children had night-time hypoglycaemia with simultaneous hypoinsulinaemia. Insulin profiles correlated poorly with the HbA1c and peak C-peptide values.(ABSTRACT TRUNCATED AT 250 WORDS)