Comparison of continuous subcutaneous insulin infusion with multiple insulin injections using the NovoPen

The Review of Insulin Pens-Past, Present, and Look to the Future

Currently, there are about 150-200 million diabetic patients treated with insulin globally. The year 2021 is special because the 100th anniversary of the insulin discovery is being celebrated. It is a good occasion to sum up the insulin pen technology invention and improvement which are nowadays the leading mode of an insulin delivery. Even though so many years have passed, insulin is still administered subcutaneously, that is why devices to deliver it are of great importance. Insulin pens have evolved only through the last decades (the reusable, durable pens, and the disposable, prefilled pens) and modern smart insulin pens have been developed in the last few years, and both types of the devices compared to traditional syringes and vials are more convenient, discrete in use, have better dosing accuracy, and improve adherence. In this review, we will focus on the history of insulin pens and their improvement over the previous decades.

Continuous subcutaneous insulin infusion versus multiple daily injections in children and young people at diagnosis of type 1 diabetes: the SCIPI RCT

BACKGROUND

The risk of developing long-term complications of type 1 diabetes (T1D) is related to glycaemic control and is reduced by the use of intensive insulin treatment regimens: multiple daily injections (MDI) (≥ 4) and continuous subcutaneous insulin infusion (CSII). Despite a lack of evidence that the more expensive treatment with CSII is superior to MDI, both treatments are used widely within the NHS.

OBJECTIVES

(1) To compare glycaemic control during treatment with CSII and MDI and (2) to determine safety and cost-effectiveness of the treatment, and quality of life (QoL) of the patients.

DESIGN

A pragmatic, open-label randomised controlled trial with an internal pilot and 12-month follow-up with 1 : 1 web-based block randomisation stratified by age and centre.

SETTING

Fifteen diabetes clinics in hospitals in England and Wales.

PARTICIPANTS

Patients aged 7 months to 15 years.

INTERVENTIONS

Continuous subsutaneous insulin infusion or MDI initiated within 14 days of diagnosis of T1D.

DATA SOURCES

Data were collected at baseline and at 3, 6, 9 and 12 months using paper forms and were entered centrally. Data from glucometers and CSII were downloaded. The Health Utilities Index Mark 2 was completed at each visit and the Pediatric Quality of Life Inventory (PedsQL, diabetes module) was completed at 6 and 12 months. Costs were estimated from hospital patient administration system data.

OUTCOMES

The primary outcome was glycosylated haemoglobin (HbA_1c) concentration at 12 months. The secondary outcomes were (1) HbA_1c concentrations of < 48 mmol/mol, (2) severe hypoglycaemia, (3) diabetic ketoacidosis (DKA), (4) T1D- or treatment-related adverse events (AEs), (5) change in body mass index and height standard deviation score, (6) insulin requirements, (7) QoL and (8) partial remission rate. The economic outcome was the incremental cost per quality-adjusted life-year (QALY) gained.

RESULTS

A total of 293 participants, with a median age of 9.8 years (minimum 0.7 years, maximum 16 years), were randomised (CSII, n = 149; MDI, n = 144) between May 2011 and January 2015. Primary outcome data were available for 97% of participants (CSII, n = 143; MDI, n = 142). At 12 months, age-adjusted least mean squares HbA_1c concentrations were comparable between groups: CSII, 60.9 mmol/mol [95% confidence interval (CI) 58.5 to 63.3 mmol/mol]; MDI, 58.5 mmol/mol (95% CI 56.1 to 60.9 mmol/mol); and the difference of CSII - MDI, 2.4 mmol/mol (95% CI -0.4 to 5.3 mmol/mol). For HbA_1c concentrations of < 48 mmol/mol (CSII, 22/143 participants; MDI, 29/142 participants), the relative risk was 0.75 (95% CI 0.46 to 1.25), and for partial remission rates (CSII, 21/86 participants; MDI, 21/64), the relative risk was 0.74 (95% CI 0.45 to 1.24). The incidences of severe hypoglycaemia (CSII, 6/144; MDI, 2/149 participants) and DKA (CSII, 2/144 participants; MDI, 0/149 participants) were low. In total, 68 AEs (14 serious) were reported during CSII treatment and 25 AEs (eight serious) were reported during MDI treatment. Growth outcomes did not differ. The reported insulin use was higher with CSII (mean difference 0.1 unit/kg/day, 95% CI 0.0 to 0.2 unit/kg/day; p = 0.01). QoL was slightly higher for those randomised to CSII. From a NHS perspective, CSII was more expensive than MDI mean total cost (£1863, 95% CI £1620 to £2137) with no additional QALY gains (-0.006 QALYs, 95% CI -0.031 to 0.018 QALYs).

LIMITATIONS

Generalisability beyond 12 months is uncertain.

CONCLUSIONS

No clinical benefit of CSII over MDI was identified. CSII is not a cost-effective treatment in patients representative of the study population.

FUTURE WORK

Longer-term follow-up is required to determine if clinical outcomes diverge after 1 year. A qualitative exploration of patient and professional experiences of MDI and CSII should be considered.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN29255275 and EudraCT 2010-023792-25.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 42. See the NIHR Journals Library website for further project information. The cost of insulin pumps and consumables supplied by F. Hoffman-La Roche AG (Basel, Switzerland) for the purpose of the study were subject to a 25% discount on standard NHS costs.

A cluster randomised trial, cost-effectiveness analysis and psychosocial evaluation of insulin pump therapy compared with multiple injections during flexible intensive insulin therapy for type 1 diabetes: the REPOSE Trial

BACKGROUND

Insulin is generally administered to people with type 1 diabetes mellitus (T1DM) using multiple daily injections (MDIs), but can also be delivered using infusion pumps. In the UK, pumps are recommended for patients with the greatest need and adult use is less than in comparable countries. Previous trials have been small, of short duration and have failed to control for training in insulin adjustment.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of pump therapy compared with MDI for adults with T1DM, with both groups receiving equivalent structured training in flexible insulin therapy.

DESIGN

Pragmatic, multicentre, open-label, parallel-group cluster randomised controlled trial, including economic and psychosocial evaluations. After participants were assigned a group training course, courses were randomly allocated in pairs to either pump or MDI.

SETTING

Eight secondary care diabetes centres in the UK.

PARTICIPANTS

Adults with T1DM for > 12 months, willing to undertake intensive insulin therapy, with no preference for pump or MDI, or a clinical indication for pumps.

INTERVENTIONS

Pump or MDI structured training in flexible insulin therapy, followed up for 2 years. MDI participants used insulin analogues. Pump participants used a Medtronic Paradigm^® Veo^TM (Medtronic, Watford, UK) with insulin aspart (NovoRapid, Novo Nordisk, Gatwick, UK).

MAIN OUTCOME MEASURES

Primary outcome - change in glycated haemoglobin (HbA_1c) at 2 years in participants whose baseline HbA_1c was ≥ 7.5% (58 mmol/mol). Key secondary outcome - proportion of participants with HbA_1c ≤ 7.5% at 2 years. Other outcomes at 6, 12 and 24 months - moderate and severe hypoglycaemia; insulin dose; body weight; proteinuria; diabetic ketoacidosis; quality of life (QoL); fear of hypoglycaemia; treatment satisfaction; emotional well-being; qualitative interviews with participants and staff (2 weeks), and participants (6 months); and ICERs in trial and modelled estimates of cost-effectiveness.

RESULTS

We randomised 46 courses comprising 317 participants: 267 attended a Dose Adjustment For Normal Eating course (132 pump; 135 MDI); 260 were included in the intention-to-treat analysis, of which 235 (119 pump; 116 MDI) had baseline HbA_1c of ≥ 7.5%. HbA_1c and severe hypoglycaemia improved in both groups. The drop in HbA_1c% at 2 years was 0.85 on pump and 0.42 on MDI. The mean difference (MD) in HbA_1c change at 2 years, at which the baseline HbA_1c was ≥ 7.5%, was -0.24% [95% confidence interval (CI) -0.53% to 0.05%] in favour of the pump (p = 0.098). The per-protocol analysis showed a MD in change of -0.36% (95% CI -0.64% to -0.07%) favouring pumps (p = 0.015). Pumps were not cost-effective in the base case and all of the sensitivity analyses. The pump group had greater improvement in diabetes-specific QoL diet restrictions, daily hassle plus treatment satisfaction, statistically significant at 12 and 24 months and supported by qualitative interviews.

LIMITATION

Blinding of pump therapy was not possible, although an objective primary outcome was used.

CONCLUSION

Adding pump therapy to structured training in flexible insulin therapy did not significantly enhance glycaemic control or psychosocial outcomes in adults with T1DM.

RESEARCH PRIORITY

To understand why few patients achieve a HbA_1c of < 7.5%, particularly as glycaemic control is worse in the UK than in other European countries.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN61215213.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 20. See the NIHR Journals Library website for further project information.

Needle with a novel attachment versus conventional screw-thread needles: a preference and usability test among adults with diabetes and impaired manual dexterity

BACKGROUND

NovoTwist(®) (Novo Nordisk A/S, Bagsværd, Denmark) is an insulin pen needle that features a novel attachment and detachment system. The aim of this test was to assess overall preference and handling of NovoTwist compared with conventional screw-thread needles in people with type 1 or type 2 diabetes.

METHODS

One hundred twenty adults with type 1 or type 2 diabetes and manual dexterity dysfunction who were currently self-injecting with an insulin pen were included in this open-label, randomized, crossover test. Participants were stratified according to the impact that manual dexterity problems had on their ability to inject insulin (1 = no effect at all; 4 = a lot), and those rated as 1 were excluded from subanalyses because of low numbers. Following instruction, participants attached the needle to Next Generation FlexPen(®) (Novo Nordisk A/S), made an injection into a foam cushion, and detached the needle; this process was repeated three times with NovoTwist and the participant's current screw-thread needle (or NovoFine(®) [Novo Nordisk A/S]) in a random order. Responses to questions on user experience with each needle were subsequently recorded on a 6-point rating scale (1 = very difficult; 6 = very easy).

RESULTS

Significantly more respondents had a preference for NovoTwist (79%) compared with the conventional screw-thread needles (21%, P < 0.001). Significantly more respondents preferred NovoTwist for both ease of attachment (80%, P < 0.001) and ease of detachment (74%, P < 0.001). Most respondents found NovoTwist the most appropriate needle for performing everyday injections (71%, P < 0.001).

CONCLUSIONS

Such preference by patients has a positive impact on the treatment of diabetes as NovoTwist may alleviate the burden of performing everyday injections through its ease of use.

A review of 25 years' experience with the NovoPen family of insulin pens in the management of diabetes mellitus

NovoPen, the first insulin pen, was introduced in 1985. This review article is an update of a review paper published in 2006 on 20 years' use of the NovoPen family of insulin pens in the management of diabetes mellitus. The literature searches conducted in the earlier review article were updated with search results for new articles published since April 2005. This was followed by an iterative search of references cited in identified publications and by searches of abstracts from proceedings of major international diabetes conferences since 2005. Most of the original studies identified in the 2006 review showed that insulin regimens using the NovoPen family of insulin pens were at least as effective (and in some cases superior) in maintaining glycaemic control and were as safe (in terms of hypoglycaemia) as conventional insulin regimens employing vials and syringes. Most patients preferred the various NovoPen insulin pens over vials and syringes, with some evidence suggesting that the use of discreet devices, such as those of the NovoPen family, facilitates intensive insulin therapy regimens, thereby helping to improve lifestyle flexibility. The new search results showed that the current generation of the device for the adult population, NovoPen 4, retains these benefits and further meets patients' needs by improving ease of use, convenience and discretion, which may be particularly important for those with manual dexterity, visual or auditory impairments. There was also evidence that healthcare professionals would be more likely to recommend NovoPen 4 to their patients than other devices. The recently introduced NovoPen Echo, designed specifically for the paediatric population, combines half-increment dosing with a memory function that can be used to retrieve information about the time and amount of the last dose, potentially reducing the fear of double dosing or missing a dose. Evidence obtained from the new searches suggested that paediatric patients, their parents and healthcare professionals were highly satisfied with NovoPen Echo overall, with most paediatric patients rating it their favourite pen compared with other insulin pens. In conclusion, new data published over the last 5 years on the use of NovoPen devices add to the large body of published evidence supporting the patient-related benefits of durable insulin injection pens in the treatment of diabetes since the first such pen was introduced in 1985. Together, the benefits of NovoPen are considered likely to improve both patients' quality of life and their compliance with therapy.

Continuous subcutaneous insulin infusion (CSII) versus multiple insulin injections for type 1 diabetes mellitus

BACKGROUND

Type 1 diabetes is a metabolic disorder resulting from a defect in insulin secretion. Onset of type 1 diabetes mellitus may occur at any age and it is one of the most common chronic diseases of childhood and adolescence. Since there are no interventions known to prevent onset, it is vital that effective treatment regimes are available. Glycaemic control is maintained by replacement of insulin and may be in the form of 'conventional' insulin therapy (multiple injections per day) or continuous subcutaneous insulin infusion (CSII).

OBJECTIVES

To assess the effects of CSII compared to multiple insulin injections (MI) in people with type 1 diabetes mellitus.

SEARCH STRATEGY

Studies were obtained from electronic searches of The Cochrane Library, MEDLINE, EMBASE and CINAHL.

SELECTION CRITERIA

Studies were included if they were randomised controlled trials comparing CSII with three or more insulin injections per day (MI) in people with type 1 diabetes mellitus.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted characteristics of included studies. Authors contacted study investigators to obtain missing information. Generic inverse variance meta-analyses using a random-effects model were performed.

MAIN RESULTS

Twenty three studies randomised 976 participants with type 1 diabetes to either intervention. There was a statistically significant difference in glycosylated haemoglobin A1c (HbA1c) favouring CSII (weighted mean difference -0.3% (95% confidence interval -0.1 to -0.4). There were no obvious differences between the interventions for non-severe hypoglycaemia, but severe hypoglycaemia appeared to be reduced in those using CSII. Quality of life measures suggest that CSII is preferred over MI. No significant difference was found for weight. Adverse events were not well reported, no information is available on mortality, morbidity and costs.

AUTHORS' CONCLUSIONS

There is some evidence to suggest that CSII may be better than MI for glycaemic control in people with type 1 diabetes. Non-severe hypoglycaemic events do not appear to be reduced with CSII. There is insufficient evidence regarding adverse events, mortality, morbidity and costs.

Continuous subcutaneous insulin infusion versus multiple daily insulin injections in patients with diabetes mellitus: systematic review and meta-analysis

AIMS

We compared the effects of continuous subcutaneous insulin infusion (CSII) with those of multiple daily insulin (MDI) injections on glycaemic control, risk of hypoglycaemic episodes, insulin requirements and adverse events in type 1 and type 2 diabetes mellitus.

METHODS

The electronic databases MEDLINE, EMBASE and CENTRAL were systematically searched for randomised controlled trials up to March 2007. A systematic review and meta-analysis were performed.

RESULTS

Overall, 22 studies were included (17 on type 1 diabetes mellitus, two on type 2 diabetes mellitus, three on children). With regard to adults with type 1 diabetes mellitus, our meta-analysis found a between-treatment difference of -0.4% HbA(1c) (six studies) in favour of CSII therapy. Available median rates of mild or overall hypoglycaemic events were comparable between the different interventions (1.9 [0.9-3.1] [CSII] vs 1.7 [1.1-3.3] [MDI] events per patient per week). Total daily insulin requirements were lower with CSII than with MDI therapy. In patients with type 2 diabetes mellitus, CSII and MDI treatment showed no statistically significant difference for HbA(1c). The incidence of mild hypoglycaemic events was comparable between the treatment groups. In adolescents with type 1 diabetes mellitus, glycated haemoglobin and insulin requirements were significantly lower in the CSII groups; no data were available on hypoglycaemic events. The only study performed in younger children did not provide enough data for conclusive inferences. No overall conclusions were possible for severe hypoglycaemia and adverse events for any of the different patient groups due to rareness of such events, different definitions and insufficient reporting.

CONCLUSIONS/INTERPRETATION

CSII therapy in adults and adolescents with type 1 diabetes mellitus resulted in a greater reduction of glycated haemoglobin, in adult patients without a higher rate of hypoglycaemia. No beneficial effect of CSII therapy could be detected for patients with type 2 diabetes mellitus.

Glycaemic control with modified intensive insulin injections (MII) using insulin pens and premixed insulin in children with type-1 diabetes: a randomized controlled trial

The objective of this study was to compare glycemic control and insulin dosage in children with type 1 diabetes treated by a modified intensified insulin therapy MII using insulin pens (and premixed and regular insulin) with those on conventional insulin therapy. This was a longitudinal, randomized controlled trial for 6 months or more. From a cohort of 125 children with previously diagnosed type-1 diabetes (more than a year after diagnosis) two groups were randomly selected Group AI (n=20) and Group B (n=20). Group AI children and 10 children with recently diagnosed type 1 diabetes (Group AII) were allocated to MII using regular insulin and premixed insulin (30/70 and 40/60 and 50/50). Group B patients continued their conventional insulin therapy for the whole period of the trial. The main outcome measures were glycemic control measured by mean blood glucose concentration and percentage of glycated haemoglobin and total daily insulin dose. Mean blood glucose concentrations before the three main meals, and at midnight, (148, 147, 179 and 127 mg/dl, respectively) were lower in children receiving intensified MII compared with those receiving conventional insulin therapy (192, 174, 194 and 179 mg/dl, respectively) (standardized mean difference 34+/-15 mg/dl), equivalent to a difference of 1.9+/-0.8 mmol/l. This improved control during MII was achieved with no change in the average daily insulin dose in group-AI. In group-AII insulin dose decreased significantly during their first 6 moths of treatment (honeymooning). Glycemic control is better during MII using insulin pens and premixed and regular insulin compared with conventional insulin therapy, without any significant change in insulin dose needed to achieve this level of control. The difference in glycemic control between the two methods is significant and could reduce the risk of micro-vascular complications.

A Review of 20??Years??? Experience with the Novopen?? Family of Insulin Injection Devices

NovoPen, the first insulin pen injector, was introduced in 1985. This article reviews the published evidence over two decades of use of the NovoPen family of injection devices in diabetes management. A search for NovoPen publications from 1985 onwards was conducted in the following databases: MEDLINE/PubMed, Cochrane Database of Systematic Reviews, American College of Physicians Journal Club, Database of Abstract Reviews and Effects, and Cochrane Controlled Trials Register. Publications were examined and underwent a selection process to identify studies of NovoPen devices (NovoPen [1], NovoPen 2, NovoPen 1.5 and NovoPen 3) in the diabetes/insulin therapy area that contained evidence of the effects of NovoPen in a variety of categories. Of the studies identified, most showed that insulin regimens using the NovoPen family of devices are at least as effective (and in some cases superior) in maintaining glycaemic control and are as safe (in terms of hypoglycaemia) as conventional insulin regimens employing syringes. The published evidence identified also showed that insulin administration via NovoPen devices was for most patients easier, more convenient and quicker than with conventional syringes and that most patients preferred the various NovoPen devices over syringes. There was also some evidence that the use of discreet devices, like those of the NovoPen family, facilitates adherence to intensive insulin therapy regimens, helps to improve lifestyle flexibility and reduces injection pain compared with conventional syringe-based regimens. Together these benefits of NovoPen devices are considered likely to improve both patients' quality of life and compliance with therapy. In conclusion, a large body of published evidence accumulated over the past two decades testifies to the patient-related benefits of the NovoPen family of insulin injection devices in the treatment of diabetes.

Validity and reliability of an instrument for assessing health-related quality of life and treatment preferences: the Insulin Delivery System Rating Questionnaire

OBJECTIVE

To provide a preliminary assessment of the validity and reliability of a new measure of health-related quality of life (HRQOL) and treatment preference for insulin delivery systems.

RESEARCH DESIGN AND METHODS

Study participants were 197 adults with type 1 or type 2 diabetes who completed the Insulin Delivery System Rating Questionnaire (IDSRQ), a self-administered questionnaire developed for this study. The IDSRQ assessed patient perceptions of treatment satisfaction, impact of treatment on daily activities, clinical efficacy, diabetes-related worries and social burdens, psychological well-being, and overall treatment system preference of patients using continuous subcutaneous insulin infusion (CSII) and multiple daily injections (MDI).

RESULTS

The IDSRQ subscales had acceptable reliability (alpha = 0.67-0.92, median 0.82) and test-retest correlations (intraclass correlation coefficient 0.67-0.94, median 0.88). Floor effects (0-10%, median 0%) and ceiling effects (0-18%, median 4%) were minimal. There were statistically significant differences (P < 0.05) between patients using CSII and MDI on all IDSRQ subscales except psychological well-being (P = 0.096); differences in means were 0.3-1.4 SD units (median 0.9). Multiple regression analysis (controlling for age, sex, and type of diabetes) showed that treatment satisfaction, perceived clinical efficacy, and psychological well-being were independently associated with overall treatment preference and accounted for half of the difference in preference between CSII and MDI patients.

CONCLUSIONS

Preliminary findings suggest that the IDSRQ is a valid and reliable measure of HRQOL and treatment preferences for insulin delivery systems. The subscales are comprehensive, sensitive to differences in user populations, and account for most of the preference for a particular insulin delivery system.

Persistent poor glycaemic control in adult Type 1 diabetes. A closer look at the problem

Around 25% of the adult Type 1 diabetes population is in persistent poor glycaemic control and thus at increased risk of developing microvascular complications. We here discuss correlates of long-standing poor glycaemic control and review the efficacy of clinical strategies designed to overcome persistent poor control. Only a few studies have identified determinants and correlates of long-standing poor glycaemic control in Type 1 diabetes. There is some evidence implicating genetic factors, as well as lower economic status, and psychological factors, including lack of motivation, emotional distress, depression and eating disorders. Ways of improving glycaemic control include strategies to enable self-management, e.g. motivational strategies, coping-orientated education, psychosocial therapies, and/or intensifying insulin injection therapy plus continuous subcutaneous insulin infusion. Long-standing poor glycaemic control appears to be a heterogeneous and complex phenomenon, for which there is no simple, single solution. Comprehensive psycho-medical assessment in diabetes care may prove useful in tailoring interventions. Further research is warranted, to increase our understanding how psychosocial and biomedical factors, separately and in interaction, determine poor outcomes in Type 1 diabetes.

Glycaemic control in a type 1 diabetes clinic for younger adults

BACKGROUND

In the Diabetes Control and Complications Trial (DCCT, 1993) tight diabetes control (HbA1c <7%) was associated with significantly less microvascular complications compared to 'conventionally' treated type 1 patients.

AIM

To assess the effectiveness of a dedicated young-adult type 1 diabetes clinic in achieving HbA1c levels <7% between 1991 and 2001.

DESIGN

Retrospective review of case-notes.

METHODS

All patients who attended the clinic in the first six years (1991 to 1996) were studied. All were offered at least two appointments per year. Case-notes were reviewed up to December 2001.

RESULTS

We treated 386 type 1 patients (59.8% male, mean age 28.7 years, mean duration diabetes 9.5 years). After a mean follow-up of 7.7 years, 261 (67.6%) had attended in the past 2 years, 22 (5.8%) were known to have died, 11 (2.8%) had transferred to another clinic and 92 (23.8%) had repeatedly failed to attend appointments for 2 years. Over 11 years, the total mean (SD) HbA1c was 9.19% (1.3). Only 3.4% of patients achieved an average HbA1c of <7% during the study period, and 80% of patients had average HbA1c levels of >8%.

DISCUSSION

Despite regular specialist physician, specialist diabetes nurse and dietician input, encouragement of multiple daily insulin injections and repeatedly following-up failed appointments (including home visits), fewer than 1:20 patients achieved the DCCT target of mean HbA1c <7%. Tight diabetes control is rare in a routine clinic setting.

A review of basal insulins

Tight glycaemic control (ideally, HbA1c<7%) is central to reducing the risk of long-term complications of diabetes. This approach, for both Type 1 and Type 2 diabetes, commonly involves the use of basal insulin, and must be achieved with minimal risk of hypoglycaemia (particularly nocturnal episodes). Indeed, concern around hypoglycaemia is a major barrier to achieving tight glycaemic control, and is a common problem with those protracted-acting insulins most frequently used in clinical practice for basal insulin supply. Other drawbacks include inter- and intra-patient variability that compromises dosing reproducibility and unsuitability for single daily dosing. New long-acting human insulin analogues with action profiles designed to overcome these problems are now available in clinical practice or are under evaluation in clinical trials. Clinical evidence suggests efficacy and safety advantages for these analogues over NPH insulin (the most commonly used basal insulin), and may bring closer the goal of tight glycaemic control in patients with diabetes.

Insulin pump therapy: a meta-analysis

OBJECTIVE

To conduct a meta-analysis of the metabolic and psychosocial impact of continuous subcutaneous insulin infusion (CSII) therapy on adults, adolescents, and children.

RESEARCH DESIGN AND METHODS

Studies were identified and data regarding study design, year of publication, sample size, patient's age, diabetes duration, and duration of CSII therapy were collected. Means and SDs for glycohemoglobin, blood glucose, insulin dosages, and body weight for CSII and comparison conditions were subjected to meta-analytic procedures. Data regarding pump complications and psychosocial functioning were reviewed descriptively.

RESULTS

A total of 52 studies, consisting of 1,547 patients, were included in the meta-analysis. Results indicate that CSII therapy is associated with significant improvements in glycemic control (decreased glycohemoglobin and mean blood glucose). A descriptive review of potential complications of CSII use (e.g., hypoglycemia, diabetic ketoacidosis [DKA], pump malfunction, and site infections) suggests a decreased frequency of hypoglycemic episodes but an increased frequency of DKA in studies published before 1993.

CONCLUSIONS

CSII therapy is associated with improved glycemic control compared with traditional insulin therapies (conventional therapy and multiple daily injections) and does not appear to be associated with significant adverse outcomes. Additional studies are needed to further examine the relative risks of CSII therapy, including the potential psychosocial impact of this technologically advanced therapy.

Less severe hypoglycaemia, better metabolic control, and improved quality of life in Type 1 diabetes mellitus with continuous subcutaneous insulin infusion (CSII) therapy; an observational study of 100 consecutive patients followed for a mean of 2 years

AIMS

To compare glycaemic control, occurrence of acute complications, and diabetes-specific quality of life in Type 1 diabetic patients (on intensified conventional insulin treatment (ICT)) before and after initiation of CSII.

METHODS

One hundred and three patients (58 women) started CSII between October 1995 and April 1999 in our department. The indication for CSII was optimization of metabolic control and improvement of flexibility of life style (OF group) in 60 patients (58%), and prevention of severe hypoglycaemia (HY group) in 43 patients. Mean age at initiation of CSII was 33 +/- 11 years (OF 33 +/- 10, HY 33 +/- 11 (mean +/- sd)), diabetes duration 18 +/- 9 years (OF 16 +/- 9, HY 20 +/- 9). Three patients stopped CSII, mean duration of CSII of the remaining 100 patients was 1.8 +/- 1.2 years. The occurrence of hypoglycaemia, ketoacidosis and skin abscesses was assessed retrospectively for the 12 months before starting CSII, and recorded continuously during CSII. Quality of life was assessed with a validated, diabetes-specific questionnaire before and after CSII in 50 patients.

RESULTS

The incidence of serious hypoglycaemia (any external help) was reduced from 1.23 (OF 0.0; HY 2.93) during ICT to 0.29 cases/patient per year (OF 0.09; HY 0.55) during CSII. The incidence of severe hypoglycaemia (SH) (treated with i.v. glucose or glucagon injection) fell from 0.70 (OF 0.0; SH 1.67) during ICT to 0.06 cases/patient per year (OF 0.02; HY 0.12) during CSII. HbA1c improved from 7.7 +/- 1.1% to 7.2 +/- 1.0% (P < 0.001) (OF 7.8% vs. 7.2%; HY 7.6% vs. 7.2%). During CSII the incidence of abscesses was 0.11 and of ketoacidosis 0.01 cases/patient per year. Quality of life assessments showed significant improvement in all parameters during CSII.

CONCLUSIONS

In our cohort of Type 1 diabetic patients, we observed a substantial decrease of hypoglycaemia along with a significant fall of HbA1c. Quality of life on CSII was improved when compared with ICT.

Glycaemic control with continuous subcutaneous insulin infusion compared with intensive insulin injections in patients with type 1 diabetes: meta-analysis of randomised controlled trials

OBJECTIVE

To compare glycaemic control and insulin dosage in people with type 1 diabetes treated by continuous subcutaneous insulin infusion (insulin infusion pump therapy) or optimised insulin injections.

DESIGN

Meta-analysis of 12 randomised controlled trials.

PARTICIPANTS

301 people with type 1 diabetes allocated to insulin infusion and 299 allocated to insulin injections for between 2.5 and 24 months.

MAIN OUTCOME MEASURES

Glycaemic control measured by mean blood glucose concentration and percentage of glycated haemoglobin. Total daily insulin dose.

RESULTS

Mean blood glucose concentration was lower in people receiving continuous subcutaneous insulin infusion compared with those receiving insulin injections (standardised mean difference 0.56, 95% confidence interval 0.35 to 0.77), equivalent to a difference of 1.0 mmol/l. The percentage of glycated haemoglobin was also lower in people receiving insulin infusion (0.44, 0.20 to 0.69), equivalent to a difference of 0.51%. Blood glucose concentrations were less variable during insulin infusion. This improved control during insulin infusion was achieved with an average reduction of 14% in insulin dose (difference in total daily insulin dose 0.58, 0.34 to 0.83), equivalent to 7.58 units/day.

CONCLUSIONS

Glycaemic control is better during continuous subcutaneous insulin infusion compared with optimised injection therapy, and less insulin is needed to achieve this level of strict control. The difference in control between the two methods is small but should reduce the risk of microvascular complications.

Continuous subcutaneous insulin infusion at 25 years: evidence base for the expanding use of insulin pump therapy in type 1 diabetes

Continuous subcutaneous insulin infusion (CSII) is used in selected type 1 diabetic subjects to achieve strict blood glucose control. A quarter of a century after its introduction, world-wide use of CSII is increasing. We review the evidence base that justifies this increase, including effectiveness compared with modern intensified insulin injection regimens and concern about possible complications. Review of controlled trials shows that, in most patients, mean blood glucose concentrations and glycated hemoglobin percentages are either slightly lower or similar on CSII versus multiple insulin injections. However, hypoglycemia is markedly less frequent than during intensive injection therapy. Ketoacidosis occurs at the same rate. Nocturnal glycemic control is improved with insulin pumps, and automatic basal rate changes help to minimize a prebreakfast blood glucose increase (the "dawn phenomenon") often seen with injection therapy. Patients with "brittle" diabetes characterized by recurrent ketoacidosis are often not improved by CSII, although there may be exceptions. We argue that explicit clinical indications for CSII are helpful; we suggest the principal indications for health service or health insurance-funded CSII should include frequent, unpredictable hypoglycemia or a marked dawn phenomenon, which persist after attempts to improve control with intensive insulin injection regimens. In any circumstances, candidates for CSII must be motivated, willing and able to undertake pump therapy, and adequately psychologically stable. Some diabetic patients with well-defined clinical problems are likely to benefit substantially from CSII and should not be denied a trial of the treatment. Their number is relatively small, as would therefore be the demand on funds set aside for this purpose.

Type 1 diabetes mellitus in a routine diabetes clinic: the association of psycho-social factors, diabetes knowledge and glycaemic control to insulin regime

In controlled trials intensified diabetes therapy including multiple insulin injection regimes has been shown to improve glycaemic and microvascular disease outcomes in insulin dependent diabetes but this is not clear in routine outpatient practice. We undertook a pragmatic cross sectional study of 200 patients with Type 1 diabetes aged 18-50 years. There were 108 on two insulin injections/day (conventional) and 92 on four injections/day (multiple) with no significant difference for age, sex, social class, body mass index, diabetes duration, hypoglycaemia rate or complications prevalence. The relationship of insulin injection regime used with diabetes knowledge, psychological factors and glycaemic control outcomes was evaluated. Percent glycated HbA1c concentrations (normal range < 5.5%) were worse in the multiple injection group (7.5 +/- 1.7 vs. 6.8 +/- 1.4%, P < 0.001) (mean +/- SD). Their scores for diabetes knowledge (72.5 +/- 8.2 vs. 69.0 +/- 9.8, P < 0.01) were better but treatment satisfaction (29.9 +/- 5.1 vs. 28.5 +/- 6.1, ns) and well-being (49.1 +/- 10.7 vs. 46.5 +/- 12.7, ns) scores were not. Parameters of perceived locus of control were (multiple v conventional): personal (self), 24.5 +/- 5.0 vs. 22.3 +/- 5.9, P < 0.05; medical (doctor), 11.8 +/- 5.1 vs. 10.8 +/- 5.8, ns; situational (chance), 7.9 +/- 5.1 vs. 8.9 +/- 5.9, ns. In multiple regression of HbA1c versus multiple variables only insulin regime (P < 0.001) was significant. We conclude that in routine clinical practice the use of intensive insulin regimes are associated with worse glycaemic control despite patients being marginally more knowledgeable and self directed.

Influence of intensified insulin regimen on quality of life and metabolic control in insulin-dependent diabetes mellitus

Seventy-eight non-randomized patients with IDDM, aged 33.8 +/- 9.6 years (mean +/- S.D.), with a duration of diabetes of 16.6 +/- 9.5 years and a HbA1c level of 8.0% +/- 1.5 at baseline were included in the study. The effects of a change from a 3-dose insulin regimen using conventional syringes to a treatment mode using 4 injections per day with a pen injector on metabolic control, perceived distress from diabetes on everyday life and correspondence between expectations and experiences of treatment during a 1-year trial were assessed. The experience measures were registered at baseline and after 3 and 12 months, respectively. HbA1c levels were measured every 3 months. Neither the metabolic control nor the body mass index or rate of hypoglycemic episodes changed during the study period. However, the patients experienced a decreased distress from diabetes, which appeared during the first 3 months and remained unchanged thereafter. The expectations of advantages from the intensified insulin therapy were generally high and were mostly either fulfilled or exceeded by experiences. We conclude that multiple insulin injection therapy, under routine treatment conditions, is subjectively preferable to patients and has favourable effects on their quality of life although something more is required in order to also achieve an improvement of metabolic control.

Audit of multiple insulin injection regimens in a large outpatient diabetic population

One hundred out-patients treated by multiple insulin injection regimens underwent clinical audit by retrospective analysis of their case-notes. Patients had been on multiple insulin injection therapy (MIIT) for 1.0-4.5 years (median, 3.6 years) and had had diabetes for 2 months-33 years (median, 8.7 years) at the time of starting pen therapy. Median daily insulin dose per patient did not differ significantly following stabilisation on MIIT or at latest follow-up. The median glycated haemoglobin did not change during each of the 4 years of follow-up. During the year prior to commencing MIIT the patients showed no significant alteration in body weight. Patients' weights rose significantly during each subsequent year. Median weight gains were 0.9 kg (P less than 0.005) during the first year, 1.4 kg (P less than 0.005) during the second year, 0.9 kg (P less than 0.05) during the third year and 1.4 kg (P less than 0.05) during year 4. No such weight gain was recorded in a control group of 30 patients matched for age and duration of diabetes and treated by twice daily insulin injections. Multiple insulin injection regimens used over prolonged periods in a routine clinic setting do not alter metabolic control. However, continuing weight gain appears to occur despite similar daily insulin doses.

Evaluation of a pen injector system for growth hormone treatment

The increasing use of human growth hormone (hGH) treatment has resulted in the introduction of a number of alternative delivery systems to conventional syringe and needle administration. We examined patients' evaluation of a new delivery system, the Kabipen (Kabi-Vitrum). We also assessed the accuracy of hGH delivery by the Kabipen. Of the 77 survey respondents 13 had used only the Kabipen, 14 the syringe only, and 50 had used both systems. Altogether 46 (92%) of those who had used both systems preferred the Kabipen. Children over 10 years were more likely to self administer hGH with the Kabipen (64%) than syringe (25%). Patient instructions, convenience of use, and comfort of use were rated better for the Kabipen than syringe. With a dose setting of 2 units the Kabipen delivered a mean (SD) of 1.997 (0.073) units with 102.5% recovery from a unit cartridge. In summary the Kabipen is an accurate device clearly preferred by the majority of hGH recipients surveyed.

Deterioration in blood glucose control in females with diabetes changed to a basal-bolus regimen using a pen-injector

Although the basal-bolus regimen of insulin delivery is more physiological than conventional twice daily insulin it does not usually improve blood glucose control. Having recently withdrawn 3 patients from pen-injector therapy for deteriorated blood glucose control we examined the records of all our diabetic patients on a pen-injector for at least 1 year. Of the 51 patients identified, 3 had died, 2 moved away, and 4 patients (3 females) had pen-injector therapy withdrawn for poor control; 3 patients had inadequate records. The remaining 21 males and 18 females were well matched for age, duration of diabetes, and duration of pen-injector treatment. Blood glucose control deteriorated significantly during pen-injector therapy in female patients (9.6 +/- 1.2 to 10.7 +/- 1.4%, p = 0.02), but not in the males (9.3 +/- 1.3 vs 9.4 +/- 1.4%, NS). Weight and insulin dose did not change significantly in any patient. Blood glucose control may deteriorate in young women with diabetes changed to insulin therapy with a pen-injector.