Optical Nanosensors for Real-Time Feedback on Insulin Secretion by β-Cells

Quantification of insulin is essential for diabetes research in general, and for the study of pancreatic β-cell function in particular. Herein, fluorescent single-walled carbon nanotubes (SWCNT) are used for the recognition and real-time quantification of insulin. Two approaches for rendering the SWCNT sensors for insulin are compared, using surface functionalization with either a natural insulin aptamer with known affinity to insulin, or a synthetic lipid-poly(ethylene glycol) (PEG) (C₁₆ -PEG(2000Da)-Ceramide), both of which show a modulation of the emitted fluorescence in response to insulin. Although the PEGylated-lipid has no prior affinity to insulin, the response of C₁₆ -PEG(2000Da)-Ceramide-SWCNTs to insulin is more stable and reproducible compared to the insulin aptamer-SWCNTs. The SWCNT sensors successfully detect insulin secreted by β-cells within the complex environment of the conditioned media. The insulin is quantified by comparing the SWCNTs fluorescence response to a standard calibration curve, and the results are found to be in agreement with an enzyme-linked immunosorbent assay. This novel analytical tool for real time quantification of insulin secreted by β-cells provides new opportunities for rapid assessment of β-cell function, with the ability to push forward many aspects of diabetes research.

A meta-analysis and meta-regression on the prevalence of lipohypertrophy in diabetic patients on insulin therapy

AIMS OF THE STUDY

This study aimed to assess the prevalence of lipohypertrophy (LH) in diabetes mellitus (DM) patients on insulin therapy and identify factors influencing the prevalence rates through a meta-analysis and meta-regression.

METHODS

Databases of PubMed, Embase, Scopus, and Google Scholar were screened from inception to 20th Aug 2020. Data on prevalence was transformed using the logit transformation for pooling the proportions using the DerSimonian-Laird meta-analysis model. Random-effects meta-regression analysis was performed to assess the influence of the following moderators on the pooled prevalence: male gender, mean age, type of DM, DM duration, duration of insulin therapy, needle re-users, rotation of injection site, HbA_1c, insulin dose, ≥8mm needle users and mean number of injections/day.

RESULTS

Forty-five studies were included. LH was diagnosed by observation and palpation by all studies. On meta-analysis of data from 26,865 participants, the overall prevalence of LH was found to be 41.8% (95% CI: 35.9% to 47.6%). On region-wise analysis, pooled prevalence of LH in Europe was 44.6% (95% CI: 37.5% to 51.8%) in Africa was 34.8% (95% CI: 16.9% to 52.8%) and in Asia was 41.3% (95% CI: 27.2% to 55.3%). The pooled prevalence of LH in studies only on type 1 and type 2 DM patients was 39.9% (95% CI: 28.3% to 51.6%) and 45.9% (95% CI: 29.5% to 62.4%) respectively. Only insulin duration was found to significantly influence the prevalence of LH on meta-regression.

CONCLUSION

Our study indicates that the prevalence of LH in DM patients on insulin therapy is estimated to be 41.8%. The longer the duration of insulin therapy, the higher is the prevalence of LH.

Bruising: A Neglected, Though Patient-Relevant Complication of Insulin Injections Coming to Light from a Real-Life Nationwide Survey

INTRODUCTION

Despite the availability of sophisticated devices and suitable recommendations on how to best perform insulin injections, lipohypertrophy (LH) and bruising (BR) frequently occur as a consequence of improper injection technique.

AIM

The purpose of this nationwide survey was to check literature-reported LH risk factors or consequences for any association with BR METHOD: This was a cross-sectional, observational, multicenter study based on the identification of skin lesions at all patient-reported insulin injection sites in 790 subjects with diabetes. General and injection habit-related elements were investigated as possible BR risk factors.

RESULTS

While confirming the close relationship existing between LH and a full series of factors including missed injection site rotation, needle reuse, long-standing insulin treatment, frequent hypoglycemic events (hypos), and great glycemic variability (GV), the observed data could find no such association with BR, which anyhow came with high HbA1c levels, missed injection site rotation, and long-standing insulin treatment.

CONCLUSION

BR most likely depends on the patient's habit of pressing the injection pen hard onto the skin. Despite being worrisome and affecting quality of life, BR seems to represent a preliminary stage of LH but does not affect the rate of hypos and GV.

TRIAL REGISTRATION

207/19.09.2017.

Insulin-Induced Skin Lipohypertrophy in Type 2 Diabetes: a Multicenter Regional Survey in Southern Italy

INTRODUCTION

Lipohypertrophies (LHs) due to incorrect insulin injection techniques have been described in the literature for decades. Their rate averages 38%, but this is still controversial because of the vast range reported by different publications, most of which fail to describe the selected detection protocol and therefore are not entirely reliable. We still need to identify the real LH rate, and only consistently using a standardized method in a large cohort of insulin-treated (IT) patients make this possible.

METHODS

Our group performed thorough clinical skin examinations on patients suffering from type 2 diabetes mellitus (T2DM): 1247 IT T2DM outpatients were examined according to a standardized protocol, previously published elsewhere, as well as an ultrasound scan of the same skin areas to assess the degree of concordance between the two methods and to evaluate the demographic, clinical, and behavioral risk factors (RF) as well as metabolic consequences of identified LHs.

RESULTS

The concordance between the two methods was 99%. Identified risk factors for LHs were needle reuse, failure to rotate injection sites, and ice-cold insulin injections. High HbA1c values, wide glycemic variability, and longstanding proneness to hypoglycemia with a high rate of ongoing hypoglycemic events proved to be significantly associated with LHs, too; the same applied to cardiovascular and renal complications as well as to living alone and being retired.

CONCLUSIONS

Based on a strict well-structured methodology, our data confirmed what has already been reported in the literature on factors leading to, or associated with, LHs and, for the first time in adults, indicated cryotrauma from ice-cold insulin injections and specific social conditions as factors facilitating LH occurrence. HCPs should therefore plan a yearly clinical examination of all injection sites to improve patient quality of life through better glucose control and a reduced rate of hypoglycemic events.

TRIAL REGISTRATION

Trial registration no. 127-11.01.2019, approved by the Scientific and Ethics Committee of Campania University "Luigi Vanvitelli," Naples, Italy.

Impact of Insulin Injection and Infusion Routines on Lipohypertrophy and Glycemic Control in Children and Adults with Diabetes

INTRODUCTION

Proper insulin injection/infusion is essential to optimize insulin absorption and action. Guidelines on insulin injection techniques are available. Lipohypertrophy (LH) is a local complication of insulin therapy, which results in erratic absorption and impaired glycemic control.

METHODS

Children and adults with type 1 diabetes on insulin injection or infusion were enrolled in the study. Subjects were interviewed and filled in a questionnaire on injection/infusion routines. Sites of injection/infusion were examined by trained diabetes educators, and capillary HbA1c was obtained.

RESULTS

One hundred sixty-nine subjects (104 children) with type 1 diabetes were enrolled; 119 were on multiple daily injection (MDI) and 50 on insulin pump therapy. Seventy-two percent and 82% of children and adults, respectively, rotate site at every injection; 78% of pump users change infusion set and 74% rotate site at 2-3 days. Thirty-nine percent and 32% of children and adults had LH. HbA1c was lower in children and adults with no LH (P < 0.001). An association was seen between LH and rotation frequency in children (P = 0.026). LH was the most common skin complication in the MDI group, while nodules, allergy marks and hyperpigmentation were seen in pump users.

CONCLUSION

Proper injection/infusion routines impact glycemic control and skin health. Education and examination of injection sites remain a crucial part of diabetes management.

Ultrasound detection of insulin-induced lipohypertrophy in Type 1 and Type 2 diabetes

AIMS

To define standard criteria for the detection of lipohypertrophy using ultrasonography and to determine the accuracy of this method.

METHOD

Individuals using insulin therapy for ≥2 years with unknown lipohypertrophy status were enrolled at a diabetes education centre. A team of diabetes educator nurses performed a clinical examination for evidence of lipohypertrophy and a separate team of ultrasonographers examined participants in a blinded fashion.

RESULTS

The echo signature for lipohypertrophy consisted of location in the subcutaneous layer and lesions that were 1) well circumscribed either by hyperechoic foci with defined borders or a nodular shape with a hypoechoic halo, 2) heterogeneous in echotexture compared with surrounding tissue, 3) associated with distortion of surrounding connective tissue with 4) absence of vascularity and 5) absence of capsule. Ultrasonography identified individuals with lipohypertrophy significantly more frequently than inspection or palpation (P<0.0001). Inter-observer agreement was moderate (κ=0.50) and limited by the presence of subclinical lesions in 73% of the participants.

CONCLUSIONS

The ultrasound detection of lipohypertrophy is consistent with clinical examination and is reproducible using a defined echo signature. (ClinicalTrials.gov registration no: NCT02348099).

A Systematic Review of Ultrasound-Detected Lipohypertrophy in Insulin-Exposed People with Diabetes

INTRODUCTION

Lipohypertrophy (LH) is a common complication occurring in diabetes individuals. The most common methods used include palpation, visual examination and/or ultrasound (US). To date, there is limited information on the detection sensitivity among the different techniques used to identify LH. This systematic review aimed to identify studies that examined insulin-related LH using US detection to identify the prevalence, characteristics and morphology of LH, and to compare US and clinical palpation methods for detecting LH.

METHODS

Three electronic databases were systematically searched for studies detecting LH using US in insulin users. Articles were screened for eligibility and included studies were appraised using quality assessment tools. The quality of the evidence was evaluated using Grading of Recommendations Assessment, Development and Evaluation, and the extracted data was synthesised narratively.

RESULTS

Sixteen articles were included in the review providing data on 1722 patients. The prevalence of LH prevalence varied from 14.5% to 88% (median 56.6%). Identified risk factors for the development of included insulin injection behaviour such as a lack of injection site rotation and social factors such as low education level. Four studies compared LH detection by US to palpation, providing inconsistent results. One study showed that palpation detected 64% more LH, whilst two studies demonstrated that US identified 50% more sites and extended areas of LH (additional ~ 5 cm²). Another study provided comparable estimates between palpation and US in clinicians trained to detect LH (97%).

CONCLUSION

The evidence highlights a lack of congruence in results pertaining to the detection sensitivity of US and palpation for LH sites. More research with robust study design is needed to verify whether clinically palpation is sufficient to detect LH, or whether US would increase the precision of LH assessment to help address this common clinically significant problem.

Turkish Insulin Injection Techniques Study: Complications of Injecting Insulin Among Turkish Patients with Diabetes, Education They Received, and the Role of Health Care Professional as Assessed by Survey Questionnaire

INTRODUCTION

Using the Turkish and rest of world (ROW) Injection Technique Questionnaire (ITQ) data we address key insulin injection complications.

METHODS

Summarized in first ITQ paper.

RESULTS

Nearly one-third of Turkish insulin users described lesions consistent with lipohypertrophy (LH) at their injection sites and 27.4% were found to have LH by the examining nurse (using visual inspection and palpation). LH lesions in the abdomen and thigh of Turkish patients are slightly smaller than those measured in ROW but more than half of Turkish patients who have LH continue to inject into them at least daily. More than a quarter of Turkish patients have frequent unexplained hypoglycemia and nearly 2 out of 5 have glycemic variability, both of which have been linked to the presence of LH and the habit of injecting into it. Nearly half of Turkish injectors report having pain on injection. Of these, just over half report having painful injections only several times a month or year (i.e., not with every injection). In Turkey the diabetes nurse has by far the major role in teaching patients how to inject. Nearly 40% of Turkish injectors get their sites checked at least annually, and a larger proportion than ROW had received recent (within the last 12 months) instruction on how to inject properly.

CONCLUSION

Turkish patients and professionals have clearly made progress in injection technique, but there are still considerable challenges ahead which the new Turkish guidelines will help address.

FUNDING

BD Diabetes Care.

Insulin Injection Technique Questionnaire: results of an international study comparing Brazil, Latin America and World data

BACKGROUND

In 2014-2015, the largest international survey of insulin injection technique in patients with diabetes taking insulin was conducted in 42 countries, totaling 13,289 participants. In Brazil, patients from five public health centers were included. This study aims to evaluate insulin injection technique in Brazilian patients and compare results with Latin America (LatAm) and World data.

METHODS

The insulin Injection Technique Questionnaire (ITQ) survey consisted of an initial patient section (questions applied by an experienced nurse), followed by observation of injection technique and examination of the injection sites by the health care professional.

RESULTS

In Brazil, 255 patients were evaluated: 25% had type 1 diabetes mellitus (T1DM) and 75% had T2DM. In this study, 79% of patients injected less than 4 times a day, and 17.3% used insulin pens, compared to 28% in LatAm and 86% worldwide. Syringes were used by 78% of patients in Brazil, compared to 65% in LatAm and 10% globally. Differences in needle length were substantial-nearly 64% in Brazil inject with 8 mm length needle compared to 48% in LatAm and 27% worldwide. Additionally, 48% of patients in Brazil skip doses, 80% reuse pen needles and 57% reuse syringes with 27% having lipohypertrophy by exam.

CONCLUSION

Brazilian patients use syringes more and pens less, inject with larger needles and have more lipohypertrophy when compared to Latin America and World data. Their re-use of needles and syringes is also high. This study showed that in Brazil, teaching of proper injection technique has to be more widespread, and more intensive during diabetes educational sessions, and the type of delivered supplies must be updated to smaller, shorter needles preferred by patients, in order to facilitate adherence to treatment. From the ITQ, we conclude that there are many aspects of insulin injection technique that may be improved in Brazil.

Insulin-Related Lipohypertrophy: Lipogenic Action or Tissue Trauma?

Lipohypertrophy has been suggested as an outcome of lipogenic action of insulin and/or injection-related tissue trauma. In a cross-sectional study, we evaluated the predictors of lipohypertrophy in 372 type 1 diabetes patients (mean age 17.1 years) receiving subcutaneous insulin with pen and/or syringes for ≥3 months. On examining injection sites with inspection and palpation technique, 62.1% patients demonstrated lipohypertrophy. Univariate analysis showed that gender, BMI, HbA1c, injection device, rotation, injection area, needle length, insulin regimen, and total daily dose of insulin were associated with lipohypertrophy (p < 0.05). Notably, the mean needle reuse was comparable in patients with or without lipohypertrophy (8.1 vs. 7.2, p = 0.534). In multivariate logistic regression, gender, HbA1c, TDD, injection devices, and needle length lost its significance. Further, injections over smaller area (≤8.5 × 5.5 cm) and non-rotation of sites were found to be strongest independent predictor of lipohypertrophy (p < 0.0005 for both) with increased odds of 23.2 (95% CI 9.1-59.2) and 6.3 (95% CI 3.4-11.9) times, respectively. Being underweight was also a significant independent predictor (odds ratio [OR] 13.0 [95% CI 2.2-75.2], p = 0.004). Compared to rapid plus long-acting analogs, regular insulin plus long-acting analogs and conventional premixed insulin users had 3.2 (95% CI 1.5-6.8, p = 0.003) and 4.6 (95% CI 1.4-15.7, p = 0.014) fold higher risk of lipohypertrophy (mean injection frequency 4.01 vs. 4.01 vs. 2.09, respectively). Sub-group analysis showed that lipohypertrophy was 79% less likely in patients with multiple daily injections (≥4) than twice-daily regimen (OR 0.21, p < 0.0005). Moreover, lipohypertrophy was reduced to half with bolus doses of rapid-acting insulin analogs than regular insulin (p = 0.003), even though mean injection frequency was comparable (4.01 vs. 3.93, p = 0.229). This difference was statistically insignificant for basal doses with NPH or long-acting analogs (p = 0.069). Therefore, injection area, rotation, BMI, and insulin regimen are the best predictors of lipohypertrophy and together could correctly identify lipohypertrophy status in 84.4% patients with excellent discrimination capability (AUC = 0.906, p < 0.0005). In conclusion, findings of our study suggest that delivering rapidly absorbed insulin analogs over large injection area along with greater split of total daily doses reduce insulin-induced lipogenesis and outplay tissue trauma added through frequent injections and needle reuse.

An Effective Intervention for Diabetic Lipohypertrophy: Results of a Randomized, Controlled, Prospective Multicenter Study in France

BACKGROUND

Lipohypertrophy (LH) is highly prevalent and is potentially harmful to insulin-injecting patients.

METHODS

In this study, we assessed the impact of injection technique (IT) education, including use of a 4-mm pen needle on insulin-treated patients with clinically observed LH in a randomized, controlled, prospective multicenter study in France with follow-up of 6 months. Intensive education and between-visit reinforcement were given to the intervention group. Control patients received similar messages at study outset.

RESULTS

A total of 123 patients were recruited (age 52.1 ± 15.7 years; men 70.7%; body mass index >30 kg/m²: 34.2%; type 1: 53.7%; years with diabetes mellitus: 18.1 ± 10.5), of which 109 patients were included in the final analysis. The intervention group (n = 53) showed a significant decrease of total daily dose of insulin (average at baseline: 54.1 IU) at 3 months (T-3) and 6 months (T-6), reaching just over 5 IU versus baseline (P = 0.035). Corresponding, although not significant, decreases occurred in controls (n = 56); between-group differences were not significant. There were significant decreases in HbA1c (up to 0.5%) at T-3 and T-6 in both groups, with no significant differences between groups. A significant number of intervention patients improved their IT habits; about half achieved ideal IT habits by T-3 versus a quarter of control patients. By T-6, 2/3 of intervention patients achieved either ideal or acceptable IT habits, while only 1/3 of control patients did.

CONCLUSIONS

Our intervention was effective in both study arms, however, to a greater degree and more rapidly in the intervention group. Widespread application of this intervention could be highly cost-effective.

Prevalence of lipohypertrophy in insulin-treated diabetes patients: A systematic review and meta-analysis

AIMS/INTRODUCTION

Insulin-treated diabetes patients are at high risk for lipohypertrophy (LH), but this clinical problem has been overlooked by some medical professionals. In addition, studies differed from each other significantly in regard to the prevalence of LH. The present systematic review aimed to determine pooled prevalence levels of LH among insulin-injecting diabetes patients.

MATERIALS AND METHODS

Four electronic databases (PubMed, EMBASE, The Cochrane Library and Scopus) were searched for eligible studies from their inception until April 2017, and reference lists were searched manually to identify additional studies. Studies containing data on LH in patients with diabetes mellitus were included. Meta-analysis was carried out with a random effects model.

RESULTS

A total of 26 studies with a total of 12,493 participants met the inclusion criteria. Meta-analysis showed that the pooled prevalence of LH was 38% (95% confidence interval [CI] 29-46%, I2 = 99.1%). The main influence on LH was the type of diabetes mellitus. The pooled prevalence of LH among patients with type 2 diabetes mellitus was higher than patients with type 1 diabetes mellitus (49%, 95% CI 23-74% vs 34%, 95% CI 19-49%). The pooled prevalence of LH of studies involving a mixed type of diabetes mellitus was 37% (95% CI 25-48%, I2 = 98.3%).

CONCLUSION

The prevalence of LH was high in insulin-treated diabetes patients. It showed that diabetes nurses should screen for LH regularly in their patients, and teach them how to prevent LH in their daily management of diabetes mellitus.

In-Hospital Administration of Insulin by Nurses in Northern Greece: An Observational Study

OBJECTIVE

The purpose of this study is to explore current practice regarding insulin administration by nurses in a Greek public hospital.

DESIGN AND METHODS

A mixed-methods qualitative data collection design was used with ad hoc nonparticipant observation and post hoc interviews with the staff involved. Insulin management and administration was observed and compared to international guidelines. A sample of 20 nurses from two medical wards was assessed on 100 occasions of insulin administration, and 8 nurses were subsequently interviewed.

RESULTS

Inter-rater agreement was found to be satisfactory (average κ 0.840). In 61% of all instances, nurses washed their hands before administering insulin, and, in 70%, they donned gloves before injections. In 64.5% of all instances, the nurses did not clean the insulin bottle before inserting the needle, and in 42.7% of instances, they did not check for air bubbles in the syringe. In 89.1% of instances, nurses did not check the injection site for appropriateness or other possible complications. However, in 90.9%, they cleaned the skin at the injection site with an alcohol swab. In 70.9% of all instances, the needle was placed vertically to the skin but without a skinfold. In 89.1% of instances, post-injection care was rated as poor.

CONCLUSION

Overall, compliance with international guidelines regarding insulin administration techniques, as observed in these sample wards, is not satisfactory. Nurses in this Greek hospital tend to administer subcutaneous injections in ways not reflected in current research findings, practice guidelines, or evidence-based care recommendations. Evidently, Greek nurses in this sample require updating on current evidence-based practice, clinical guidelines, and protocols of care regarding routine insulin administration.

Indian Injection Technique Study: Injecting Complications, Education, and the Health Care Professional

INTRODUCTION

Using the Indian and rest of world (ROW) injection technique questionnaire (ITQ) data, we address key insulin injection complications.

METHODS

In 2015 we conducted an ITQ survey throughout India involving 1011 patients. Indian values were compared with those from 41 other countries participating in the ITQ, known here as ROW.

RESULTS

More than a quarter of Indian insulin users described lesions consistent with lipohypertrophy (LH) at their injection sites and approximately 1 in 5 were found to have LH by the examining nurse (using visual inspection and palpation). Just over half of Indian injectors report having pain on injection. Of these, 4 out of 5 report having painful injections only several times a month or year (i.e., not with every injection). Doctors and diabetes educators in India (as opposed to nurses) have a larger role in teaching patients how to inject than they do in ROW. Despite this specialized approach, a very high percentage of patients report that they have not been trained (at least cannot remember being trained) in a wide range of essential injection topics. Only about 30% of Indian injectors get their sites checked at least annually, with nearly a third only having sites checked when they specifically complained and nearly 4 out of 10 never having had their sites checked.

CONCLUSION

Indian HCPs can clearly do a better job covering all the vital topics essential to proper injection habits.

UK lipohypertrophy interventional study

INTRODUCTION

Lipohypertrophy (LH) is one of the most common complications of insulin therapy. We conducted a prospective study in 18 UK centres to assess the impact of a targeted LH intervention on a range of clinical, biological and socio-economic parameters.

METHODS

Seventy-five insulin-injecting patients were recruited randomly and were followed prospectively for 3-6months, with results compared to baseline values. Interventions included the use of an intensive education program and a switch to a 4mm pen needle.

RESULTS

At all injection sites LH decreased significantly by the end of the study, either disappearing completely or shrinking by approximately 50% from its original diameter. Injections into LH decreased by more than 75% by the end. Most patients were not correctly rotating injection sites at the beginning but by the end most were, by a 5-fold margin. Only 1/3 of our subjects used the 4mm needle at the beginning of the study, however, virtually all did by study end. The mean HbA1c improved by more than 4mmol/L and there were significantly lower levels of unexpected hypoglycaemia and glucose variability. Total daily doses of insulin dropped by an average of 5.6 IU by study end.

CONCLUSIONS

We believe the impressive clinical improvements seen with training to prevent LH can be achieved by wide adoption of the interventions outlined in this study.

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.

Worldwide Injection Technique Questionnaire Study: Injecting Complications and the Role of the Professional

From February 1, 2014, through June 30, 2015, 13,289 insulin-injecting patients from 423 centers in 42 countries participated in one of the largest surveys ever performed in diabetes. The first results of this survey are published elsewhere in this issue. Herein we report that the most common complication of injecting insulin is lipohypertrophy (LH), which was self-reported by 29.0% of patients and found by physical examination in 30.8% by health care professionals (HCPs). Patients with LH consumed a mean of 10.1 IU more insulin daily than patients without LH. Glycated hemoglobin levels averaged 0.55% higher in patients with vs without LH. Lipohypertrophy was associated with higher rates of unexplained hypoglycemia and glycemic variability as well as more frequent diabetic ketoacidosis, incorrect rotation of injection sites, use of smaller injection zones, longer duration of insulin use, and reuse of pen needles (each P<.05). Routine inspection of injection sites by the HCP was associated with lower glycated hemoglobin levels, less LH, and more correct injection site rotation. Patients were also more likely to rotate correctly if they received injection instructions from their HCP in the past 6 months. Fewer than 40% of patients claimed to have gotten such instructions in the past 6 months, and 10% said that they have never received training on how to inject correctly despite injecting for a mean of nearly 9 years. Use of these data should stimulate renewed commitment to optimizing insulin injection practices.

Lipodystrophy in Insulin-Treated Subjects and Other Injection-Site Skin Reactions: Are We Sure Everything is Clear?

Physicians and patients have long been aware of skin lesions at the sites of insulin injections, referred to as lipodystrophy that can present as lipoatrophy (LA) or lipohypertrophy (LH). However, the reported prevalence of these different skin lesions varies widely, emphasizing the need for a correct identification method. In this short review we discuss LA and LH and also take into account other skin lesions, such as bruising, as well as different needle injuries, including those associated with the subcutaneous injection of pegvisomant (a drug aimed at counteracting the high levels of growth hormone associated with acromegaly), long-acting exenatide (a glucagon-like peptide-1 receptor agonist), and anti-tumor necrosis factor-alpha biologic agents (used against Crohn's disease). In these latter cases specific studies are warranted to understand the pathophysiological background and possible prevention. However, the most common lesion is still insulin injection site-related LD, so a strong effort has to be made to avoid the confusion generated by previously misleading classifications which were barely able to reliably distinguish between LA and LH.

A suitable palpation technique allows to identify skin lipohypertrophic lesions in insulin-treated people with diabetes

BACKGROUND

Lipohypertrophy (LH) is a major complication of subcutaneous insulin treatment brought about by multiple overlapping injections and/or needle reuse. It is responsible for unacceptable glucose oscillations due to a high rate of hypoglycaemic episodes and rebound glucose spikes. Skin ultrasound scans (USS), the gold standard for its detection, is too expensive for screening purposes.

AIMS

To define a structured method allowing health professionals (HPs) to identify LH lesions as inexpensively and correctly as possible.

METHODS

Out of 129 insulin-treated people with diabetes identified by USS as having LH lesions, only 40 agreed to participate in the study (24 females, age 54 ± 15 years, daily insulin dosage 57 ± 12 IU). Each was blindly examined by four well trained and four non-trained HPs according to a standard method involving repeated well codified maneuvers.

RESULTS

A specific training allowed inexperienced HPs to acquire high diagnostic accuracy in identifying LH lesions independent of site, size, shape, and even BMI. This kind of training also allowed to reach a 97 % consistency rate among HPs as compared to USS, while the lack of training was associated with a wide variability and inconsistency of identification results.

CONCLUSIONS

Diabetes teams should follow systematically the simple procedure reported in this paper for the diagnosis of LH and try to get it further implemented and progressively refined in large scale studies. This would have a major impact on patient education in terms of (1) correct injection technique and (2) ability to identify lesions early enough to prevent poor metabolic outcome.

Antinociceptive properties of nasal delivery of neurotoxin-loaded nanoparticles coated with polysorbate-80

Neurotoxin-1 (NT) is an analgesic peptide which is endowed an exceptional specificity of action that blocks transmission of the nerve impulse. The aim of this study was to evaluate the potential application of nanoparticles technology as drug carrier system for the nasal delivery of NT. Mice were administered intranasally (i.n.) with NT (NT-P-NP), free NT solution (F-NT) and intravenously (i.v.) with NT (IV-NT) respectively. The NT levels in animal brain and antinociceptive activity of NT were analyzed. The result on brain transport showed that nanoparticles could exert enhanced delivery of NT into the brain significantly after i.n. administration. The results of antinociceptive activity showed that NT-P-NP increased immobility in the open-field test, both phases of formalin test were significantly inhibited by the NT-P-NP and NT-P-NP significantly inhibited the reaction time to thermal stimuli at 60 and 90 min. Both NT-P-NP and IV-NT were able to inhibit constrictions in acetic acid-induced writhing reaction. These data suggest that NT-loaded nanoparticles coated with polysorbate-80 could generate a significant improvement of drug levels in the brain. Intranasal administration of Neurotoxin-1 entrapped in nanoparticles coated with polysorbate-80 is an attractive alternative to intravenous administration.

The Third Injection Technique Workshop in Athens (TITAN)

The first Injection Technique workshop brought together endocrinologists and injection experts from around the world in Strasbourg in 1997. From its work came groundbreaking recommendations which advanced best practices in areas such as the use of a skin fold when injecting. The second Injection Technique workshop, with an expanded format including nurses and diabetes educators, took place in Barcelona in 2000. The initial stimulus to use shorter injecting needles can be said to date from this meeting. The third Injection Technique workshop was held in Athens in September 2009 and involved 127 experts from across the globe. After a comprehensive review of all publications since 2000 as well as several unpublished studies, the attendees divided into smaller groups to debate and draft new injecting recommendations based on the new data and their collective experience. This paper summarizes all the formal presentations given at this practical consensus workshop.

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.

Complexation Hydrogels for the Oral Delivery of Growth Hormone and Salmon Calcitonin

The hydrogel system of poly(methacrylic acid-co-N-vinyl pyrrolidone) was evaluated for use as an oral delivery system for growth hormone and salmon calcitonin. These proteins were selected because of their therapeutic importance and the insight provided by evaluating the delivery of a therapeutic agent with a high molecular weight (growth hormone) and a drug with a high isoelectric point (salmon calcitonin). Growth hormone loading and release studies were performed for both P(MAA-co-NVP) and P(MAA-g-PEG). Loading efficiencies for the respective systems were 50.9 ± 1.8% and 57.8 ± 4.1%; weight incorporation of the protein was determined to be 3.5 ± 0.1% and 4.0 ± 0.3%. At pH 7.4, growth hormone release of 90% occurred within 45 min for P(MAA-co-NVP) microparticles; 90% release was not achieved with P(MAA-g-PEG) microparticles until 180 min. At pH 1.2, no release occurred from P(MAA-co-NVP) microparticles but 10% release occurred from P(MAA-g-PEG) microparticles. Salmon calcitonin loading and release were shown to be affected by the negative charges of deprotonated MAA; for systems with monomer molar feed ratios of 4:1, 1:1 and 1:4 MAA:NVP, loading efficiencies were determined to be 70.6 ± 3.0%, 25.3 ± 1.2%, and 1.6 ± 1.3%. Salmon calcitonin release was minimal from the copolymer with 4:1 MAA:NVP monomer feed at pH 7.4. The release improved when the pH was raised above physiological levels. These studies confirmed that P(MAA-co-NVP) was an effective oral delivery system for high molecular weight drugs, but improvements are needed before the system could be utilized for high isoelectric point therapeutic delivery.

Results and analysis of the 2008-2009 Insulin Injection Technique Questionnaire survey

BACKGROUND

The efficacy of injection therapy in diabetes depends on correct injection technique and, to provide patients with guidance in this area, we must understand how they currently inject.

METHODS

From September 2008 to June 2009, 4352 insulin-injecting Type 1 and Type 2 diabetic patients from 171 centers in 16 countries were surveyed regarding their injection practices.

RESULTS

Overall, 3.6% of patients use the 12.7-mm needle, 1.8% use the 12-mm needle, 1.6% use the 10-mm needle, 48.6% use the 8-mm needle, 15.8% use the 6-mm needle, and 21.6% use the 5-mm needle; 7% of patients do not know what length of needle they use. Twenty-one percent of patients admitted injecting into the same site for an entire day, or even a few days, a practice associated with lipohypertrophy. Approximately 50% of patients have or have had symptoms suggestive of lipohypertrophy. Abdominal lipohypertrophy seems to be more frequent in those using the two smaller injection size areas, and less frequent in those using larger areas. Nearly 3% of patients reported always injecting into lipohypertrophic lesions and 26% inject into them sometimes. Of the 65% of patients using cloudy insulins (e.g. NPH), 35% do not remix it before use.

CONCLUSIONS

It is clear from the latest survey that we have improved in certain areas, but that, in others, we have either not moved at all or our efforts have not yielded the results we expected. The results of the present survey are available online on a country-by-country and question-by-question basis at http://www.titan-workshop.org.

Assessment of poly(methacrylic acid-co-N-vinyl pyrrolidone) as a carrier for the oral delivery of therapeutic proteins using Caco-2 and HT29-MTX cell lines

Hydrogels of poly(methacrylic acid-co-N-vinyl pyrrolidone) were synthesized and evaluated for their use as carriers for oral protein delivery. Insulin loading efficiencies were determined to be near 90% for carriers crosslinked with ethylene glycol dimethacrylate with corresponding weight incorporation levels near 12%. Although no insulin was released in gastric conditions, as desired, near instantaneous release occurred when the pH was raised to values typical of the intestinal area. Cytocompatibility studies with Caco-2 and Caco-2/HT29-MTX cultures demonstrated that microparticles did not elicit toxic effects at concentrations up to 5.0 mg/mL. Insulin transport studies revealed that the carriers did not disrupt the cell layer and thus did not change the insulin permeability in the apical-to-basolateral direction. Therefore, microparticles of this system were best suited for oral delivery of therapeutic agents that do not require transport facilitation.

Impact of Absorption and Transport on Intelligent Therapeutics and Nano-scale Delivery of Protein Therapeutic Agents

The combination of materials design and advances in nanotechnology has led to the development of new therapeutic protein delivery systems. The pulmonary, nasal, buccal and other routes have been investigated as delivery options for protein therapy, but none result in improved patient compliances and patient quality of life as the oral route. For the oral administration of these new systems, an understanding of protein transport is essential because of the dynamic nature of the gastrointestinal tract and the barriers to transport that exist.Models have been developed to describe the transport between the gastrointestinal lumen and the bloodstream, and laboratory techniques like cell culture provide a means to investigate the absorption and transport of many therapeutic agents. Biomaterials, including stimuli-sensitive complexation hydrogels, have been investigated as promising carriers for oral delivery. However, the need to develop models that accurately predict protein blood concentration as a function of the material structure and properties still exists.

Incidence of lipohypertrophy in diabetic patients and a study of influencing factors

This study examines the incidence of lipohypertrophy in diabetic individuals as well as the factors that have an influence on causing this condition. In consideration of the period of development of lipohypertrophy, the research sampling consisted of 215 diabetics who had been using insulin for at least 2 years. Observation and palpation techniques were used in assessing lipohypertrophy in these diabetics. Data were evaluated using percentages, chi(2) and logistic regression analysis. Results of the study established lipohypertrophy in 48.8% of the individuals comprising the sampling. It was seen that the incidence of lipohypertrophy in these individuals was affected by their level of education, the frequency that they changed needles, the frequency of changing their injection sites and the amount of time they had been using insulin, the difference proving to be statistically significant (p<0.05). In the logistic regression analysis, it was found that the amount of time insulin had been used (p=0.001), the frequency of changing injection sites (p=0.004) and the frequency of changing needles (p=0.004) had an influence on the development of lipohypertrophy. These results show that the amount of time insulin is used and the procedure for injection both affect the development of lipohypertrophy.