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

STAR 3 randomized controlled trial to compare sensor-augmented insulin pump therapy with multiple daily injections in the treatment of type 1 diabetes: research design, methods, and baseline characteristics of enrolled subjects

BACKGROUND

Sensor-augmented pump therapy (SAPT) integrates real-time continuous glucose monitoring (RT-CGM) with continuous subcutaneous insulin infusion (CSII) and offers an alternative to multiple daily injections (MDI). Previous studies provide evidence that SAPT may improve clinical outcomes among people with type 1 diabetes. Sensor-Augmented Pump Therapy for A1c Reduction (STAR) 3 is a multicenter randomized controlled trial comparing the efficacy of SAPT to that of MDI in subjects with type 1 diabetes.

METHODS

Subjects were randomized to either continue with MDI or transition to SAPT for 1 year. Subjects in the MDI cohort were allowed to transition to SAPT for 6 months after completion of the study. SAPT subjects who completed the study were also allowed to continue for 6 months. The primary end point was the difference between treatment groups in change in hemoglobin A1c (HbA1c) percentage from baseline to 1 year of treatment. Secondary end points included percentage of subjects with HbA1c < or =7% and without severe hypoglycemia, as well as area under the curve of time spent in normal glycemic ranges. Tertiary end points include percentage of subjects with HbA1c < or =7%, key safety end points, user satisfaction, and responses on standardized assessments.

RESULTS

A total of 495 subjects were enrolled, and the baseline characteristics similar between the SAPT and MDI groups. Study completion is anticipated in June 2010.

CONCLUSIONS

Results of this randomized controlled trial should help establish whether an integrated RT-CGM and CSII system benefits patients with type 1 diabetes more than MDI.

[Optimal timing of insulin detemir injection in patients with type 1 diabetes and poor metabolic control]

AIM

To compare different administration times of insulin detemir (IDet) in patients with type 1 diabetes and poor metabolic control.

MATERIAL AND METHODS

This 24-week open study included 39 people with type 1 diabetes mellitus (DM) randomized to one injection of IDet before lunch (mean 14.24 + or - 00.36 (+ or - SD) h) or at bedtime (23.19 + or - 0.42 h). Whenever target glycemia levels were not reached, the regimen was switched to insulin therapy with two injections (IDet-12h). Insulin aspart was used before main meals.

RESULTS

At week 24, only 12.2% of patients remained in the IDet bedtime group and 30.3% in the IDet before lunch group. The remaining 57.5% joined the IDet-12h group. There were no differences between the IDet before lunch and IDet bedtime groups. A subanalysis including the three groups demonstrated better metabolic control in the IDet before lunch group (glycosylated hemoglobin (HbA1c) 7.1 + or - 0.2 vs. 7.6 + or - 0.4 and 8.1 + or - 0.2% in IDet before-lunch, IDet bedtime and IDet-12h, respectively; p<0.05). An HbA1c value below 7% was achieved in 30.3% of the patients: 15.2% in the IDet before-lunch group, 3.3% in the IDet bedtime group and 12.2% in IDet-12h group. Quality of life did not differ among treatment groups.

CONCLUSIONS

One injection of IDet administered before lunch could improve metabolic control. However, most patients required two injections of IDet.

A cost-effectiveness analysis of continuous subcutaneous insulin injection versus multiple daily injections in type 1 diabetes patients: a third-party US payer perspective

OBJECTIVE

To estimate the long-term cost-effectiveness of using continuous subcutaneous insulin infusion (CSII) compared with multiple daily injections (MDI) of insulin in adult and child/young adult type 1 diabetes mellitus (T1DM) patients from a third-party payer perspective in the United States.

METHOD

A previously validated health economic model was used to determine the incremental cost-effectiveness ratio (ICER) of CSII compared with MDI using published clinical and cost data. The primary input variable was change in HbA(1c), and was assumed to be an improvement of -0.9% to -1.2% for CSII compared with MDI for child/young adult and adults, respectively. A series of Markov constructs simulated the progression of diabetes-related complications.

RESULTS

CSII was associated with an improvement in quality-adjusted life-years (QALYs) gained of 1.061 versus MDI for adults and 0.799 versus MDI for children/young adults. ICERs were $16,992 and $27,195 per QALY gained for CSII versus MDI in adults and children/young adults, respectively. Improved glycemic control from CSII led to a lower incidence of diabetes complications, with the most significant reduction in proliferative diabetic retinopathy (PDR), end stage renal disease (ESRD), and peripheral vascular disease (PVD). The number needed to treat (NNT) for PDR was nine patients, suggesting that only nine patients need to be treated with CSII to avoid one case of PDR. The NNT for ESRD and PVD was 19 and 41, respectively.

CONCLUSIONS

Setting the willingness to pay at $50,000/QALY, the analysis demonstrated that CSII is a cost-effective option for patients with T1DM in the United States.

A randomized prospective study of insulin pump vs. insulin injection therapy in very young children with type 1 diabetes: 12-month glycemic, BMI, and neurocognitive outcomes

OBJECTIVE

To compare glycemic control, body mass index (BMI), neurocognitive function, and parenting stress for preschool-aged diabetic children randomized to treatment either with continuous subcutaneous insulin infusion (CSII) or with intensive insulin injection therapy (IIT).

METHODS

Children <5 yr of age diagnosed with type 1 diabetes mellitus for at least 12 months were randomized to either CSII (n = 21) or IIT (n = 21) for 6 months. After 6 months, the IIT group began CSII therapy and the CSII group continued on pumps. Hemoglobin A1c (HbA1c) and BMI percent were collected at baseline, 3, 6, 9, and 12 months. Neurocognitive assessments (Developmental Test of Visual-Motor Integration and Stanford-Binet Intelligence Scale: Fourth Edition) were administered to children, and parenting and child behavior assessments (Parenting Stress Index and Child Behavior Checklist) were completed by parents and at baseline, 6, and 12 months.

RESULTS

Thirty-five children completed the study. Mean HbA1c decreased significantly over the study period (8.9% +/- 0.6 vs. 8.5% +/- 0.7, p = 0.006). Initiation of CSII resulted in an HbA1c decrease of 0.4% after 3 months (p = 0.002); however, in the CSII first group, the HbA1c at 12 months was not significantly different from study start (8.8% +/- 0.6 vs. 8.5% +/- 0.6; p = 0.4). There were no significant changes in BMI%, neurocognitive, parenting, and child behavior measures between groups.

CONCLUSION

Initiation of CSII vs. continuing IIT does not significantly influence HbA1c, BMI, neurocognitive, or parenting stress parameters in a research study setting.

Improvements in cognition, mood and behaviour following commencement of continuous subcutaneous insulin infusion therapy in children with type 1 diabetes mellitus: a pilot study

AIMS/HYPOTHESIS

Anecdotally, parents and teachers of children with type 1 diabetes mellitus report improvements in behaviour and learning following the commencement of continuous subcutaneous insulin infusion (CSII). This study aimed to investigate changes in cognition, mood and behaviour following commencement of CSII in children with type 1 diabetes.

METHODS

Children (n = 32) with type 1 diabetes aged 6-16 years and starting CSII at two Australian centres underwent behavioural, cognitive and glycaemic assessments prior to the commencement of CSII and 6-8 weeks after its start. A comprehensive cognitive test battery was administered, comprising measures of intelligence, attention, processing speed and executive skills. Behaviour and mood were assessed using the Behaviour Assessment System for Children--Second Edition. Continuous glucose monitoring was performed over a 72 h period and HbA(1c) was measured at both time-points.

RESULTS

After commencement of CSII, there were significant improvements in HbA(1c), a reduction in hyperglycaemia and blood glucose variation and an increase in normoglycaemia. Significant improvements were observed in perceptual reasoning, selective attention, divided attention, cognitive flexibility and working memory. Fewer mood-related symptoms were reported (parent, teacher and self-report) and fewer behavioural problems (parent reports)

CONCLUSIONS/INTERPRETATION

In this uncontrolled pilot study, children with type 1 diabetes demonstrated significant improvements in measures of metabolic control, mood and behaviour and in some complex cognitive skills after commencing CSII therapy.

Patient-reported outcomes for an integrated real-time continuous glucose monitoring/insulin pump system

BACKGROUND

A 16-week, two-site study evaluated outcomes for a new device (the Paradigm 722 System, Medtronic MiniMed, Northridge, CA) that combines a "smart" continuous subcutaneous insulin infusion (CSII) pump with real-time (RT) continuous glucose monitoring (CGM) and CareLinktrade mark data management software (DMS).

METHODS

CSII-naive adults with type 1 diabetes in suboptimal control (mean glycosylated hemoglobin [A1C] = 8.6%) were randomized to the control arm, consisting of multiple daily injections (MDI) and self-monitoring of blood glucose (SMBG), or the study arm (CSII with RT-CGM as an adjunct to SMBG). Participants (n = 28) completed the validated Insulin Delivery System Rating Questionnaire (IDSRQ) and the parallel Blood Glucose (BG) Monitoring System Rating Questionnaire (BGMSRQ) at study start and end. Participants in the study arm (n = 14) also completed newly developed User Acceptance Questionnaires (UAQs) for CSII, RT-CGM, and DMS at study end.

RESULTS

A1C reduction from study start to end was significant (P < 0.05) in both arms (-1.7% for study arm;-1.0% for control arm); there was no significant change in weight in either arm. The IDSRQ showed significantly (P < 0.05) greater benefit for the study arm in convenience, acceptability of BG monitoring requirements, BG control efficacy, diabetes worries, and interpersonal hassles, as well as higher overall satisfaction/preference. The BGMSRQ showed significantly (P < 0.05) greater benefit for the study arm in the BG monitoring system's ability to help manage glycemic control and less interest in changing to another BG monitoring system. The Study Arm UAQs showed positive ratings of system features.

CONCLUSIONS

Several patient-reported outcomes were significantly more positive in the study arm than the control arm; none was significantly more positive in the control arm. The features of the integrated RT-CGM/CSII system were frequently used and highly rated by participants, with high user satisfaction.

Treatment of diabetes mellitus using an external insulin pump in clinical practice

Before the initiation of insulin pump therapy, patients must be aware of the different aspects of this form of intensive insulin therapy. Most healthcare professionals recommend a sequential approach to inform patients about CSII. Factors that need to be considered in choosing an insulin pump include its safety features, durability of the device, tolerability and comfort of the catheter, user-friendliness, technical features and appearance. The initial insulin requirements need to be individualized for the given patient, using different methods to determine the appropriate dosages for the basal rate and prandial boluses. Glycaemic targets and algorithms for insulin dose adaptation need to be learned by the patients to enable them to avoid and/or correct hypo- and hyperglycaemia/ketosis episodes. Patients are also advised on how to carry out frequent self-monitoring of blood glucose-and of ketone bodies, if necessary. Insulin pumps are now able to deliver a range of basal rates and boluses that increase the flexibility of CSII. One specific issue is the approach to meal-planning, based on carbohydrate-counting or the equivalent: this method of so-called 'flexible insulin therapy' can improve metabolic control (for instance, by diminishing postprandial excursions) as well as the quality of life of patients. Evaluation of the knowledge and practices of the patient can be made through a continuous educational programme carried out by experienced nurses and physicians at the start of therapy and during follow-up. In addition, it may be necessary to identify the reasons for lack of improvement in metabolic control after several months of therapy, which include pump malfunction, cannula problems, miscalculated insulin dosages and insufficient metabolic control in specific clinical situations with a high risk of metabolic deterioration (illness, exercise, concomitant drugs). Annual assessment of the patient using an itemized checklist is required to verify the continued efficacy and safety of insulin pump therapy, two main factors of success with CSII treatment.

Clinical Usefulness of a Bolus Calculator in Maintaining Normoglycaemia in Active Professional Patients with Type 1 Diabetes Treated with Continuous Subcutaneous Insulin Infusion

This observational study assessed metabolic control in young, active professionals with type 1 diabetes treated with continuous subcutaneous insulin infusion (CSII) with or without the use of a bolus calculator. Eighteen patients aged 19 − 51 years with diabetes duration of 6 − 22 years were included; eight patients used a bolus calculator and 10 did not. Metabolic control was assessed by glycosylated haemoglobin (HbA1c) measurements and blood glucose profiles. A continuous glucose monitoring system (CGMS) was also used by three patients from each group. Mean HbA1c and fasting blood glucose levels were not significantly different between the two groups, but mean post-prandial blood glucose was significantly lower in bolus calculator users than non-users. The CGMS showed more blood glucose levels within the target range in bolus calculator users than non-users, but statistical significance was not achieved. In conclusion, a bolus calculator may help to improve post-prandial blood glucose levels in active professional type 1 diabetes patients treated with CSII, but does not have a major impact on HbA1c levels.

[Comparison between continuous subcutaneous insulin infusion and multiple daily injection regimens in adolescent with type 1 diabetes from a public health care system approach to severe hypoglycemia]

OBJECTIVE

We compared the incidence of severe hypoglycemia episodes with therapy with multiple doses of insulin (MDI) and after changing to pump (CSII).

PATIENTS AND METHODS

7 T1DM patients with 14 years median and median duration of diabetes of 8 years. We analyzed insulin requirement (U/kg/day), BMI (Kg/m(2)), HbA1c (normal range: 3.5-6.7%) one year before and one year after changing therapy. The severe hypoglycemia episodes decreased from 1.3 to 0 episodes/patient/year; p = 0.00). The insulin requirement decreased from 1.33 +/- 0.26 U/Kg/day to 0.87 +/- 0.17 U/kg/day; p = 0.04 and HbA1c decreased from 8.7 +/- 0.7% to 7.8 +/- 0.9%; p = 0.05.

CONCLUSION

CSII is efficient in decreasing severe hypoglycemia in a subgroup of T1DM using MDI also in Public Health Care System (PHCS) conditions. However, these finding should be reproduced by other Diabetes Care centers and cost studies are necessary to confirm the viability and possibility of this therapy, when necessary, to T1DM patients, which correspond to the majority of these individuals in our country, seeing in the PHCS.

Severe hypoglycaemia and glycaemic control in Type 1 diabetes: meta-analysis of multiple daily insulin injections compared with continuous subcutaneous insulin infusion

AIMS

Continuous subcutaneous insulin infusion (CSII) is a recommended treatment for reducing severe hypoglycaemia in Type 1 diabetes, but the change in hypoglycaemia compared with multiple daily insulin injections (MDI) is unclear. We therefore conducted a meta-analysis comparing severe hypoglycaemia and glycaemic control during CSII and MDI.

METHODS

Databases and literature (1996-2006) were searched for randomized controlled trials (RCTs) and before/after studies of > or = 6 months' duration CSII and with severe hypoglycaemia frequency > 10 episodes/100 patient years on MDI.

RESULTS

In 22 studies (21 reports), severe hypoglycaemia during MDI was related to diabetes duration (P = 0.038) and was greater in adults than children (100 vs. 36 events/100 patient years, P = 0.036). Severe hypoglycaemia was reduced during CSII compared with MDI, with a rate ratio of 2.89 (95% CI 1.45 to 5.76) for RCTs and 4.34 (2.87 to 6.56) for before/after studies [rate ratio 4.19 (2.86 to 6.13) for all studies]. The reduction was greatest in those with the highest initial severe hypoglycaemia rates on MDI (P < 0.001). The mean difference in glycated haemoglobin (HbA(1c)) between treatments was less for RCTs [0.21% (0.13-0.30%)] than in before/after studies [0.72% (0.55-0.90%)] but strongly related to the initial HbA(1c) on MDI (P < 0.001).

CONCLUSIONS

The severe hypoglycaemia rate in Type 1 diabetes was markedly less during CSII than MDI, with the greatest reduction in those with most severe hypoglycaemia on MDI and those with the longest duration of diabetes. The biggest improvement in HbA(1c) was in those with the highest HbA(1c) on MDI.

Long-acting insulin analogs versus insulin pump therapy for the treatment of type 1 and type 2 diabetes

Insulin pump therapy (continuous subcutaneous insulin infusion [CSII]) is now an established form of intensive insulin treatment. It is pertinent to ask, however, if multiple daily injection (MDI) regimens based on new long-acting insulin analogs such as glargine and detemir have now replaced the need for CSII. In type 1 diabetes, CSII reduces the frequency of severe hypoglycemia compared with isophane-based MDIs, but the rate of severe hypoglycemia is usually similar on glargine- or detemir-based MDIs compared with isophane-based MDIs. CSII reduces A1C and glycemic variability compared with isophane-based MDIs; but glargine and detemir do not improve A1C or variability in many patients, particularly those who are prone to hypoglycemia. Head-to-head comparisons of CSII with MDI based on glargine indicate lower A1C, fructosamine, or glucose levels on CSII. It can be concluded that long-acting insulin analogs have not yet replaced the need for insulin pump therapy in type 1 diabetes, and CSII is the best current therapeutic option for some type 1 diabetic subjects. In type 2 diabetes, CSII and MDI produce similar glycemic control, although there is little study of MDI based on long-acting analogs compared with pumps. It is possible that CSII will be beneficial in selected patient groups with type 2 diabetes, but this requires further study.

Quality of life and treatment satisfaction in adults with Type 1 diabetes: a comparison between continuous subcutaneous insulin infusion and multiple daily injections

AIMS

The aim of this case-control study was to compare quality of life (QoL) and treatment satisfaction in adults with Type 1 diabetes (T1DM) treated with either continuous subcutaneous insulin infusion (CSII) or multiple daily injections (MDI).

METHODS

Consecutive patients aged between 18 and 55 years, and attending diabetes clinics for a routine visit, completed the Diabetes-Specific Quality-of-Life Scale (DSQOLS), the Diabetes Treatment Satisfaction Questionnaire (DTSQ) and the SF-36 Health Survey (SF-36). Case (CSII) and control subjects (MDI) were recruited in a 1 : 2 ratio.

RESULTS

Overall, 1341 individuals were enrolled by 62 diabetes clinics; 481 were cases and 860 control subjects. Cases had a longer diabetes duration and were more likely to have eye and renal complications. Age, school education, occupation and HbA(1c) were similar. Of control subjects, 90% followed glargine-based MDI regimens and 10% used NPH-based MDI regimens. On multivariate analysis, after adjusting for socioeconomic and clinical characteristics, scores in the following areas of the DSQOLS were higher in cases than control subjects: diet restrictions (beta = 5.96; P < 0.0001), daily hassles (beta = 3.57; P = 0.01) and fears about hypoglycaemia (beta = 3.88; P = 0.006). Treatment with CSII was also associated with a markedly higher DTSQ score (beta = 4.13; P < 0.0001) compared with MDI. Results were similar when CSII was compared separately with glargine- or NPH-based MDI regimens.

CONCLUSIONS

This large, non-randomized, case-control study suggests quality of life gains deriving from greater lifestyle flexibility, less fear of hypoglycaemia, and higher treatment satisfaction, when CSII is compared with either glargine-based or NPH-based MDI regimens.

Prevalence and associations of psychological distress in young adults with Type 1 diabetes

AIMS

To determine the prevalence of psychological distress in young adults with Type 1 diabetes and to explore associated factors.

METHODS

Ninety-two participants with Type 1 diabetes (46 male, 46 female) attending a young adult clinic completed two psychological self-report assessments; the Centre for Epidemiological Studies-Depression Scale (CES-D) and Adult Self-Report Scale (ASR). The mean age was 21.6 +/- 2.8 years (sd) and mean duration of diabetes was 9.3 +/- 5.4 years. A questionnaire identified the method of insulin delivery, the frequency of blood glucose monitoring and hypoglycaemia requiring third-party assistance. HbA(1c) was measured.

RESULTS

Of the participants, 35.2% reported depressive symptoms (CES-D > or = 16), 23.1% indicating severe depressive symptoms (CES-D > or = 24), and 32.2, 40.4 and 35.5% of participants reported significant distress (ASR > or = 60) on the ASR total problem scales, ASR internalizing and ASR externalizing scores, respectively. Mean HbA(1c) levels were higher in participants with depressive symptoms compared with those with normal scores (CES-D > or = 16, HbA(1c)= 9.4% vs. CES-D < 16, HbA(1c)= 8.4%, P = 0.01). Factors associated with psychological distress included use of continuous subcutaneous insulin infusion (CSII) (P = 0.02) and increased frequency of hypoglycaemic episodes (P = 0.03). CSII users had higher CES-D (21.3 vs. 11.9, P = 0.001) and ASR-Total (59.7 vs. 53.0, P = 0.02) scores than non-CSII users.

CONCLUSIONS

Approximately one-third of young adults with Type 1 diabetes experience psychological distress, which is associated with poorer glycaemic control. Psychological distress was related to frequency of hypoglycaemic episodes and method of insulin administration, with significantly greater distress being observed in those using CSII. These findings support inclusion of a psychologist in the diabetes team.

Efficacy of continuous subcutaneous insulin infusion in Type 1 diabetes: a 2-year perspective using the established criteria for funding from a National Health Service

AIM

To determine the 2-year efficacy of continuous subcutaneous insulin infusion (CSII) following the current established criteria for funding of a National Health Service.

METHODS

Longitudinal, prospective, observational unicentre study. Included in the study were 153 Type 1 diabetes (T1D) subjects, previously treated with multiple daily injections (MDI) of insulin, in whom CSII was started in accordance with the criteria for reimbursement of the Catalan National Health Service. At baseline, we recorded data on age, gender, duration of the disease, body mass index (BMI), insulin dose and indications for CSII. Glycated haemoglobin (HbA(1c)) and the frequency of hypoglycaemic events were used to assess glycaemic control. Quality of life was assessed using three different self-report questionnaires. After 24 months, these same items were remeasured in all subjects. Serious adverse events and injection-site complications were also recorded.

RESULTS

In 96% of subjects, CSII indication included less than optimal glycaemic control using MDI. HbA(1c) fell from 7.9 +/- 1.3 to 7.3 +/- 1.1% (P < or = 0.001) after 24 months of CSII. Insulin requirements were significantly lower at the end of follow-up (0.55 +/- 0.21 U/kg body weight) in comparison with before use of CSII (0.70 +/- 0.20, P < or = 0.001). BMI increased from 24.0 +/- 3.1 to 24.4 +/- 3.2 kg/m(2) after 24 months (P < or = 0.025). The rate of episodes of diabetic ketoacidosis per year remained unchanged. Mild and severe hypoglycaemic episodes were significantly reduced. The scores in all subsets of the Diabetes Quality-of-Life (DQoL) questionnaire significantly improved after 24 months of CSII.

CONCLUSIONS

CSII, commenced according to the criteria for a nationally funded clinical programme, improves glycaemic control and quality-of-life outcomes with fewer hypoglycaemic episodes in T1D subjects previously conventionally treated with MDI.

International survey of insulin pump users: Impact of continuous subcutaneous insulin infusion therapy on glucose control and quality of life

AIMS

To record the characteristics and attitude of patients treated with continuous subcutaneous insulin infusion (CSII), and the impact on glycaemic control in a large number of CSII patients in routine daily life.

METHODS

A structured questionnaire was distributed to 36,450 CSII patients from Europe and North America to determine patient characteristics, therapy characteristics, medical results, complications and treatment satisfaction.

RESULTS

A 38% response rate was achieved, 92% from patients with Type 1 diabetes. The responses indicated that CSII users achieved good glycaemic control with a mean HbA(1c) level of 7.0+/-1.1%. A significant correlation was observed between HbA(1c) and the number of blood glucose measurements per day. Four to five blood glucose measurements are needed in a majority of patients to reach optimal glucose control in intensely treated diabetic patients. The clinical benefits of CSII therapy were matched by patient experience and improvements in quality of life. There were 5.74 episodes per patient year of hypoglycaemia needing assistance, although the number of serious adverse effects recorded was dependent on patient's self-reporting.

CONCLUSIONS

These data suggest patients using CSII therapy achieve good metabolic control, are highly satisfied, and experience an acceptably small number of complications.

Chronobiology in the endocrine system

Biological signaling occurs in a complex web with participation and interaction of the central nervous system, the autonomous nervous system, the endocrine glands, peripheral endocrine tissues including the intestinal tract and adipose tissue, and the immune system. All of these show an intricate time structure with rhythms and pulsatile variations in multiple frequencies. Circadian (about 24-hour) and circannual (about 1-year) rhythms are kept in step with the cyclic environmental surrounding by the timing and length of the daily light span. Rhythmicity of many endocrine variables is essential for their efficacy and, even in some instances, for the qualitative nature of their effects. Indeed, the continuous administration of certain hormones and their synthetic analogues may show substantially different effects than expected. In the design of drug-delivery systems and treatment schedules involving directly or indirectly the endocrine system, consideration of the human time organization is essential. A large amount of information on the endocrine time structure has accumulated, some of which is discussed in this review.

Systematic literature review: quality of life associated with insulin pump use in Type 1 diabetes

AIM

To review systematically the published literature addressing whether continuous subcutaneous insulin infusion (CSII) provides any quality of life benefits to people with Type 1 diabetes.

METHODS

Electronic databases and published references were searched and a consultation with two professional groups was undertaken to identify relevant studies published up to July 2005. A multistep selection process was then undertaken to identify those articles which met the specific selection criteria, which were then critically reviewed.

RESULTS

Eighty-four potential relevant articles were identified from examination of titles and abstracts published during the specified time frame. Of these, 28 articles were retrieved in full text, of which 17 fulfilled the specific criteria for inclusion. Mixed results emerged from existing literature. Of the five randomized controlled trials, three reported mixed results, with one study reporting quality of life benefits and one reporting no evidence of quality of life benefits.

CONCLUSIONS

There is conflicting evidence reported in the various studies on the quality of life benefits of CSII in Type 1 diabetes. Existing research is flawed, making a judgement about the quality of life benefits of insulin pump use difficult. There is no strong evidence against quality of life benefits associated with CSII or otherwise, with poor methodology and inconsistent assessment of quality of life clouding the issue. The lack of reported benefit is probably a function of this rather than pump therapy not offering any quality of life benefits.

Assessing quality of life for new diabetes treatments and technologies: a simple patient-centered score

BACKGROUND

A simple quality of life measure is needed for use in diabetes, particularly for the assessment of new treatments and technologies. We devised and validated a patient-centered quality of life (PCQoL) measure that should be applicable to routine clinical practice or trial of therapies.

METHODS

People with diabetes completed a two-part, PCQoL questionnaire where they nominated five aspects of general- and diabetes-related life judged most important for their overall quality of life and rated each for current level of satisfaction. Scores derived from the questionnaire were compared with a reference measure-the Diabetes Control and Complications Trial diabetes quality of life (DQoL) score. Both were repeated after 1 month. The participants were 72 diabetic patients (60% with type 1 diabetes); 29 people with type 1 diabetes were treated by continuous subcutaneous insulin infusion (CSII) and 14 were treated by multiple daily insulin injections (MDI).

RESULTS

Patients most often cited family and relationships or fear of complications and hypoglycemia as important facets of quality of life for them. The PCQoL measure was highly correlated with the reference DQoL measure (r = 0.73, p < 0.0001), had high repeatability (r = 91, p < 0.0001), and could be completed in less than 5 minutes. The test was sensitive enough to detect a better quality of life in CSII-treated patients vs MDI-treated patients.

CONCLUSION

The PCQoL measure is simple, quick, valid, and suitable for routine use in diabetes or trials of new treatments.

Management of diabetes-related hypoglycemia

Iatrogenic hypoglycemia is the main factor limiting aggressive and optimal diabetes management. Rather than being an inevitable consequence of optimal glycemic control, however, hypoglycemia is avoidable and generally straightforward to manage when it occurs. Professional caregivers, patients, and their families are often fearful of hypoglycemia, even though most episodes are minor and easily self-treated. Understanding the factors contributing to hypoglycemia risk and how to minimize its occurrence is an essential part of diabetes care. Building on the physiologic fundamentals presented in the accompanying review, the incidence, mortality/morbidity, clinical symptoms, severity classification, and psychosocial impact of hypoglycemia are described here. Appropriate selection and titration of therapeutic agents, including insulin analogs with more predictable time-action profiles than human insulin formulations, can reduce hypoglycemia risk. Patient education about hypoglycemia prevention, including symptom recognition and necessity of rapid treatment, behavioral modification, and the importance of frequent blood glucose monitoring should accompany all therapeutic interventions.

Continuous subcutaneous insulin infusion versus multiple daily injections of insulin: economic comparison in adult and adolescent type 1 diabetes mellitus in Australia

BACKGROUND

Recent meta-analyses in the published medical literature have found improved glycaemic control with continuous subcutaneous insulin infusion (CSII) compared with multiple daily injections (MDI) of insulin for patients with diabetes mellitus. In Australia, CSII is predominantly used in type 1 diabetes mellitus (T1DM) patient populations. OBJECTIVE/INTERVENTION: To project long-term costs and outcomes of CSII (Novorapid or Humalog) compared with MDI (NPH insulin plus Novorapid or Humalog) in adult and adolescent T1DM patients in Australia.

METHODS

The study was a modelling analysis utilising a lifetime horizon in adult and adolescent specialty care T1DM patient populations from Australia. Published Australian diabetes complication costs (adjusted to Australian dollars [$A], year 2006 values), treatment costs and discount rates of 5.0% per annum were applied to costs and clinical outcomes. A lifetime horizon was taken, considering only direct medical costs and excluding indirect and non-medical costs. The validated CORE diabetes model employs standard Markov/Monte Carlo simulation techniques. It was used to simulate diabetes progression in Australian adult (mean age 43 years, duration of diabetes 17 years, mean glycosylated haemoglobin [HbA(1c)] 8.2%) and adolescent (mean age 17 years, duration of diabetes 6 years, mean HbA(1c) 8.9%) patients with baseline characteristics taken predominantly from Australian National Diabetes Information Audit and Benchmarking (ANDIAB) in Australia. The main outcome measures were incremental costs and effectiveness of CSII compared with MDI in Australian adult and adolescent patients with T1DM.

RESULTS

Mean direct lifetime costs were $A34,642 higher with CSII treatment than with MDI for adult patients and $A41,779 higher for adolescent patients. Treatment with CSII was associated with an improvement in life expectancy of 0.393 years for adults compared with MDI and 0.537 years for adolescents. The corresponding gains in QALYs were 0.467 QALYs and 0.560 QALYs for adults and adolescents, respectively. This produced incremental cost effectiveness ratios (ICERs) of $A88,220 and $A77,851 per life-year gained for CSII compared with MDI for adult and adolescent T1DM patients, respectively, in Australia. These data also produced corresponding ICERs of $A74,147 per QALY and $A74,661/QALY for adult and adolescent T1DM patients, respectively. Sensitivity analyses suggested that our base-case assumptions were mostly robust with improvements in ICERs for reduction in hypoglycaemic events with CSII treatment and worse ICERs for lower HbA(1c) changes associated with CSII treatment compared with MDI.

CONCLUSIONS

Our analysis suggests that CSII is associated with ICERs in the range of $A53,022-259,646 per QALY gained, with most ICERs representing good value for money in Australia under the majority of scenarios explored.

Predictors of glycemic control on insulin pump therapy in children and adolescents with type I diabetes

OBJECTIVE

To determine variables predictive of glycemic control in a large population of pediatric patients with type 1 diabetes on continuous subcutaneous insulin infusion (CSII).

METHODS

Charts of patients on CSII for > or =1 year were reviewed. "Good" control was a priori defined as HbA1c < or =9% in patients under 12 years of age, and < or =8% in patients over 12 years.

RESULTS

Ninety-three patients were identified (57 girls and 36 boys). Their mean age at pump start was 11.6+/-3.1 years with duration of diabetes of 4.7+/-3.1 years. Average time on pump therapy was 2.4+/-0.8 years. HbA1C decreased from 8.7+/-0.9% prior to pump therapy to 8.3+/-0.6% while on CSII (p < 0.01). Despite analysis of a large number of possible predictors, only number of basal rates (4.4 versus 3.4) and younger age (10.0 years versus 13.1 years) correlated with good control.

CONCLUSION

Only younger age and use of more basal rates were predictive of good diabetes control in children using CSII. Decisions regarding which pediatric patients are most appropriate for CSII must continue to be individualized.

Determinants of glycaemic control in type 1 diabetes during intensified therapy with multiple daily insulin injections or continuous subcutaneous insulin infusion: importance of blood glucose variability

BACKGROUND AND METHODS

We investigated the factors that determine the best glycaemic control on multiple daily insulin (MDI) injections and continuous subcutaneous insulin infusion (CSII), and the hypothesis that blood glucose variability is a major determinant of control and that the resultant HbA(1c) on MDI correlates with the improvement achieved by CSII. We studied 30 type 1 diabetic subjects already receiving MDI. Renewed attempts to improve control on MDI were made for a median of five months, and then the subjects were switched to CSII. The variability of within-day and between-day blood glucose concentrations was calculated from blood glucose self-monitoring data.

RESULTS

HbA(1c) during MDI varied from 5.7 to 11.7% (mean +/- SD, 8.5 +/- 1.4%). Within- and between-day blood glucose variability correlated with HbA(1c) on MDI (r = 0.59, p < 0.001; r = 0.48, p < 0.03). Within-day variability remained an independent predictor of HbA(1c) on MDI. Mean HbA(1c) improved with CSII (to 7.3 +/- 0.9%, p < 0.001), but reduction in HbA(1c) was variable and was related to the HbA(1c) on MDI (r = 0.79, p < 0.001) and within-day variability (r = 0.56, p < 0.01). Similar results were observed for subjects treated only with glargine-based MDI.

CONCLUSIONS

The best glycaemic control achievable on MDI is related to blood glucose variability-those with the largest swings in blood glucose retaining the highest HbA(1c). The improvement in control achieved by CSII is related to HbA(1c) and blood glucose variability on MDI. Pump therapy is most effective in those worst controlled on MDI.

Cost-effectiveness of basal insulin from a US health system perspective: comparative analyses of detemir, glargine, and NPH

The purpose of this study was to compare in clinical and economic terms the long-acting insulin analogue detemir with intermediate-acting Neutral Protamine Hagedorn (NPH) insulin and with long-acting insulin glargine. Investigators used the validated Center for Outcomes Research (CORE) Diabetes Model to project clinical and cost outcomes over a 35-year base case time horizon; outcome data were extracted directly from randomized, controlled trials designed to compare detemir with NPH and with insulin glargine. Modeled patient characteristics were derived from corresponding trials, and simulations incorporated published quality-of-life utilities with cost data obtained from a Medicare perspective. Detemir, when compared with NPH, increased quality-adjusted life expectancy by 0.698 quality-adjusted life-years (QALYs). Lifetime direct medical costs were increased by 10,451 dollars per patient, although indirect costs were reduced by 4688 dollars. On the basis of direct costs, the cost per QALY gained with detemir was 14,974 dollars. In comparison with glargine, detemir increased quality-adjusted life expectancy by 0.063 QALYs, reduced direct medical costs by 2072 dollars per patient, and decreased indirect costs by 3103 dollars (dominant). Reductions in diabetes-related comorbidities were also associated with detemir in both instances, most notably in the complications of retinopathy and nephropathy. Relative reductions in rates of complications were greatest in the comparison of detemir with NPH. Results were most sensitive to variation in hemoglobin A1c (HbA1c) levels. However, variation among any of the key assumptions, including HbA1c, did not alter the relative results. Detemir represents an attractive clinical and economic intervention in the US health care setting compared with both NPH insulin and insulin glargine.

Early detection of insulin deprivation in continuous subcutaneous insulin infusion-treated patients with type 1 diabetes

BACKGROUND

This study was performed to define the clinical relevance of early changes of capillary 3beta-hydroxybutyrate (3betaOHB), for detection of metabolic deterioration before occurrence of overt diabetic ketoacidosis following interruption of continuous subcutaneous insulin infusion (CSII).

METHODS

An open clinical trial was performed with eight patients with type 1 diabetes on CSII therapy. After an overnight fast, at 8 a.m. (T0) CSII was interrupted for 4 h. At noon (T240) CSII was re-established, and at 4 p.m. (T480) the study was ended. Blood glucose (BG) and capillary and plasma 3betaOHB were measured at 30-min intervals, plasma insulin at 60-min intervals, and urinary ketones at 120-min intervals.

RESULTS

After CSII interruption mean BG increased from 149.8+/-54.4 mg/dL at T0 to 224.8+/-56.2 mg/dL at T240 (P<0.05), and mean capillary 3betaOHB increased from 0.1+/-0.1 mmol/L at T0 to 0.9+/-0.6 mmol/L at T240 (P<0.001). The rate of increase of capillary 3betaOHB was faster and significantly more relevant than that of BG (P<0.05). The restoration of CSII produced a significant reduction of mean BG and capillary 3betaOHB (T480, 119.5+/-24 mg/dL and 0.2+/-0.2 mmol/L, respectively; P<0.05 for both vs. T240). The recovery of capillary 3betaOHB was significantly faster than that of BG (P=0.03).

CONCLUSIONS

The dynamic evaluation of changes of capillary 3betaOHB levels can represent a useful support to home BG monitoring in the event of CSII interruption, providing faster information on early metabolic deterioration due to insulin deprivation and allowing preventative action for avoiding the evolution towards overt diabetic ketoacidosis. After reintroduction of insulin infusion the monitoring of the faster recovery of 3betaOHB relative to BG can provide useful information for the prevention of late hypoglycemia due to insulin overinfusion.

Comparison of the effects of continuous subcutaneous insulin infusion (CSII) and NPH-based multiple daily insulin injections (MDI) on glycaemic control and quality of life: results of the 5-nations trial

AIMS

The goal of the study was to determine whether continuous subcutaneous insulin infusion (CSII) differs from a multiple daily injection (MDI) regimen based on neutral protamine hagedorn (NPH) as basal insulin with respect to glycaemic control and quality of life in people with Type 1 diabetes.

METHODS

The 5-Nations trial was a randomized, controlled, crossover trial conducted in 11 European centres. Two hundred and seventy-two patients were treated with CSII or MDI during a 2-month run-in period followed by a 6-month treatment period, respectively. The quality of glycaemic control was assessed by HbA(1c), blood glucose values, and the frequency of hypoglycaemic events. For the evaluation of the quality of life, three different self-report questionnaires have been assessed.

RESULTS

CSII treatment resulted in lower HbA(1c) (7.45 vs. 7.67%, P < 0.001), mean blood glucose level (8.6 vs. 9.4 mmol/l, P < 0.001) and less fluctuation in blood glucose levels than MDI (+/- 3.9 vs. +/- 4.3 mmol/l, P < 0.001). There was a marked reduction in the frequency of hypoglycaemic events using CSII compared with MDI, with an incidence ratio of 1.12 [95% confidence interval (CI): 1.08-1.17] and 2.61 (95% CI: 1.59-4.29) for mild and severe hypoglycaemia, respectively. The overall score of the diabetes quality of life questionnaire was higher for CSII (P < 0.001), and an improvement in pump users' perception of mental health was detected when using the SF-12 questionnaire (P < 0.05).

CONCLUSION

CSII usage offers significant benefits over NPH-based MDI for individuals with Type 1 diabetes, with improvement in all significant metabolic parameters as well as in patients' quality of life. Additional studies are needed to compare CSII with glargine- and detemir-based MDI.

The effects of type 1 diabetes and its long-term complications on physical and mental health status

OBJECTIVE

To analyse how type 1 diabetes mellitus (DM) and the symptoms of its chronic long-term complications correlate with health status domains in the adult population in Finland.

METHODS

A representative sample of patients with type 1 DM was selected randomly from the Finnish drug reimbursement registry. Participants reported symptoms, diagnoses and treatments indicating the presence and time of appearance of long-term complications, and completed the RAND 36 questionnaire. A principal component analysis was performed to compress the eight RAND 36 dimensions into composite domains of health status. The results were validated with split-sample analysis. Regression analyses were used to estimate the effects of age, sex, symptoms of long-term complications and comorbidities on the component T-scores.

RESULTS

Of the 752 (70.8%) responders, 592 fulfilled the criteria of type 1 DM. Of these, 82.6% fully completed the RAND 36 questionnaire. Principal component analysis of our data supports the theory of the 2-factor model of health, as physical and mental health domains were reflected unambiguously by different RAND 36 dimensions. The regression results show that the symptoms of long-term complications correlate more strongly with the physical than the mental domain of health status.

CONCLUSION

Type 1 DM, and especially the symptoms of its long-term complications, correlate mainly with the physical domain of health, although the mental domain is also affected. The prevalence of long-term complications with type 1 DM is sufficiently high within the Finnish population to substantially influence the health status of people with type 1 DM.

Health-economic comparison of continuous subcutaneous insulin infusion with multiple daily injection for the treatment of Type 1 diabetes in the UK

OBJECTIVES

The aim of this study was to project the long-term costs and outcomes of continuous subcutaneous insulin infusion (CSII) compared with multiple daily injections (MDI) in patients with Type 1 diabetes in the UK.

METHODS

The CORE Diabetes Model is a peer-reviewed, validated model which employs standard Markov/Monte Carlo simulation techniques to describe the long-term incidence and progression of diabetes-related complications. It was used to simulate disease progression in a cohort of patients with baseline characteristics taken from published UK studies (mean age 26 years, duration of diabetes 12 years, mean HbA1c 8.68%). Direct costs for 2003 were calculated from a third-party payer perspective. Discount rates of 3.0% per annum were applied to costs and clinical outcomes.

RESULTS

Treatment with CSII was associated with an improvement in mean quality adjusted life expectancy (QALE) of 0.76 +/- 0.19 years compared with MDI (12.03 +/- 0.15 vs. 11.27 +/- 0.14 years). Mean direct lifetime costs were pounds 19,407 +/- 1727 higher with CSII treatment compared with MDI (pounds 80,511 +/- 1257 vs. pounds 61,104 +/- 1249). This produced an incremental cost-effectiveness ratio (ICER) of pounds 25,648 per quality-adjusted life year (QALY) gained with CSII vs. MDI. The results were most sensitive to variation in hypoglycaemia rates and altering improvements in HbA1c associated with CSII therapy compared with MDI.

CONCLUSIONS

Improvements in glycaemic control associated with CSII over MDI led to improved QALE owing to reduced incidence of diabetes-related complications. CSII was associated with an ICER of pounds 25,648 per QALY gained vs. MDI, representing good value for money by current standards in the UK.

Indications and efficacy of continuous subcutaneous insulin infusion (CSII) therapy in Type 1 diabetes mellitus: a clinical audit in a specialist service

AIM

To determine if current guidelines correctly identify patients who will benefit from continuous subcutaneous insulin infusion (CSII) therapy by comparing outcomes between Type 1 diabetic patients with recurrent severe hypoglycaemia (SH) indications with those without; and between patients without and with classic contraindications to CSII managed in a single multidisciplinary pump clinic.

METHODS

Changes in biomedical outcomes [glycated haemoglobin (HbA1c), hypoglycaemia, diabetic ketoacidosis (DKA) rates], from before CSII to the end of the study (median duration 20.5 months, range 1-192), were analysed retrospectively from data collected from notes and interviews of 40 patients. Quality of life was assessed by three validated questionnaires at study end (33 patients).

RESULTS

Twenty-five out of forty patients were started for reasons other than SH and 15 out of 40 had contraindications to CSII. Overall, CSII was associated with a reduction in HbA1c (9.6 +/- 2.7% to 8.3 +/- 1.2%, P = 0.011), SH (6.45 +/- 16.15/year to 0.34 +/- 1.01/year, P = 0.034) and DKA (1.83 +/- 4.48/year to 0.27 +/- 1.12/year, P = 0.036). The fall in SH was greater for patients started for SH (P < 0.001). However, only patients started for other indications showed a fall in HbA1c (P = 0.001). The fall in DKA rate was greater in patients with contraindications (P = 0.042), and they did not lose the other benefits of CSII therapy, including quality of life.

CONCLUSIONS

In the setting of a specialist multidisciplinary service, CSII can be an effective and safe therapy. It confers benefit outside the setting of severe hypoglycaemia and can confer benefit in some patients with classic contraindications. This questions the validity of criteria that may exclude these patients in such a service.

Optimal insulin pump dosing and postprandial glycemia following a pizza meal using the continuous glucose monitoring system

BACKGROUND

We attempted to identify an optimal insulin pump meal bolus by comparing postprandial sensor glucose values following three methods of insulin pump meal bolusing for a consistent pizza meal.

RESEARCH DESIGN AND METHODS

Twenty-four patients with type 1 diabetes participated in a study to compare postprandial glucose values following three meal bolus regimens for a consistent evening pizza meal. Each participant utilized the following insulin lispro regimens on consecutive evenings, and glucose values were tracked by the Continuous Glucose Monitoring System (CGMS, Medtronic MiniMed, Northridge, CA): (a) single-wave bolus (100% of insulin given immediately); (b) 4-h dual-wave bolus (50% of insulin given immediately and 50% given over a 4-h period); and (c) 8-h dual-wave bolus (50% of insulin given immediately and 50% given over a 8-h period). Total insulin bolus amount was kept constant for each pizza meal.

RESULTS

Divergence in blood glucose among the regimens was greatest at 8-12 h. The 8-h dual-wave bolus provided the best glycemic control and lowest mean glucose values (singlewave bolus, 133 mg/dL; 4-h dual-wave bolus, 145 mg/dL; 8-h dual-wave bolus, 104 mg/dL), leading to a difference in mean glucose of 29 mg/dL for the single-wave bolus versus the 8-h dual-wave bolus and 42 mg/dL for the 4-h dual-wave bolus versus the 8-h dual-wave bolus. The lower mean glucose in the 8-h dual-wave bolus was not associated with any increased incidence of hypoglycemia.

CONCLUSIONS

Use of a dual-wave bolus extended over an 8-h period following a pizza meal provided significantly less postprandial hyperglycemia in the late postprandial period (8-12 h) with no increased risk of hypoglycemia.

Quality of life and diabetes knowledge of young persons with type 1 diabetes: Influence of treatment modalities and demographics

OBJECTIVE

The primary objective of this descriptive study was to assess the perception of quality of life and diabetes knowledge among young persons with type 1 diabetes. The secondary objectives were to examine the influence of treatment modality (continuous subcutaneous insulin infusion vs multiple daily injections) and demographics on quality of life and diabetes knowledge of these young persons and to determine the associations between the study variables.

RESEARCH DESIGN AND METHODS

Participants aged 9 to 17 years (n=103) completed the diabetes-specific measure of quality of life and a diabetes knowledge test. Parents of these young persons completed a history questionnaire. Descriptive statistics, independent t tests, and Pearson's correlations were used to analyze the data.

RESULTS

Overall, diabetes-specific measure of quality-of-life scores indicated good quality of life among the study population. Mean scores on the impact, worry, and satisfaction subscales did not indicate negative perceptions of the disease. Body mass index was significantly inversely correlated with the satisfaction scale ( r =-0.247, P =.023). Self-rated health was negatively correlated with the impact ( r =-0.221, P =.038) and worry scale ( r =-0.294, P =.004) and positively correlated with the satisfaction scale ( r =0.291, P =.004). Seventy-two percent correct responses were given on the diabetes knowledge test. Knowledge was significantly correlated to diabetes diagnosis age ( r =0.276, P =.009) and current age ( r =0.453, P =.0005). No significant differences were observed between participants using continuous subcutaneous insulin infusion vs multiple daily injections in regard to diabetes-specific measure of quality of life and diabetes knowledge test.

CONCLUSIONS

In our study, young persons with type 1 diabetes had a positive perception of their quality of life and above-average diabetes knowledge, which were influenced by several factors, such as self-rated health, body mass index, and age at diagnosis. Dietetics professionals should assess perceived quality of life and knowledge among young persons with type 1 diabetes because these factors can potentially influence disease management and treatment compliance.

Insulin pump therapy in children and adolescents: improvements in key parameters of diabetes management including quality of life

AIMS

To determine the impact of insulin pump therapy (continuous subcutaneous insulin infusion) on key parameters of diabetes management including quality of life in children and adolescents with Type 1 diabetes mellitus (T1DM).

METHODS

All patients started on insulin pump therapy were prospectively followed before and after institution of insulin pump therapy. Data collected included age, duration of diabetes, glycated haemoglobin levels (HbA1c), anthropometric data and episodes of severe hypoglycaemia defined as hypoglycaemia resulting in coma or convulsion. A subset of patients also completed the Diabetes Quality of Life Instrument (DQOL) and Self-Efficacy for Diabetes Scale (SED) questionnaires to assess quality of life.

RESULTS

At the time of analysis, 100 patients had been managed with insulin pump therapy. The mean age when starting pump therapy was 12.5 (3.9-19.6) years. Duration of therapy ranged from 0.2 to 4.0 years (mean 1.4 years, median 1.5 years). HbA1c decreased from 8.3 +/- 0.1% prior to pump therapy to 7.8 +/- 0.1% (P < 0.0001). Episodes of severe hypoglycaemia decreased from 32.9 to 11.4 per 100 patient years. Components of quality of life measures showed improvement on pump treatment. BMI standard deviation scores (z scores) did not increase.

CONCLUSIONS

Pump therapy is proving an effective means of insulin therapy in the young patient that shows promise to improve glycaemic control with a reduction in hypoglycaemia frequency. Quality of Life measures suggest that psychosocial outcomes may be improved.

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.

What are capillary blood ketone levels in type 1 diabetic patients using CSII in normal conditions of insulin delivery?

OBJECTIVE

The aim of the study was to determine the normal level of capillary ketonemia in type 1 diabetic patients on continuous subcutaneous insulin infusion (CSII).

RESEARCH DESIGN AND METHODS

A total of 36 type 1 diabetic patients treated by external pump were studied for 2 to 3 weeks. Patients were instructed to self monitor capillary glucose and capillary ketone bodies at least 4 times per day with a handheld Medisense Optium meter and check for urinary ketone bodies in the morning and when blood glucose exceeded 2.5 g/l with a semiquantitative test. Data were collected and analysed for each period of time defined as the time interval between two changes of the infusion site. A period was considered "normal" when no problem causing any impairment in insulin delivery was detected.

RESULTS

186 periods of 2.1 +/- 0.9 days were recorded; 119 were considered normal. 1281 coupled values of glucose and betahydroxybutyrate were analysed during the so called normal periods. Mean percentage of ketonemia of 0, 0.1, 0.2, > or =0.3 mmole/l were 81.3%, 13%, 3.7% and 2% respectively whereas mean glucose level (g/l) was 1.49 +/- 0.7, 1.48 +/- 0.7, 1.59 +/- 0.8 and 1.89 +/- 0.9 respectively. Only 0.9% of betahydroxybutyrate values were > or =0.3 mmole/l when blood glucose exceeded 2.5 g/l.

CONCLUSION

Our study indicates that ketonemia self monitoring can be a valuable tool to screen insulin deficiency in patients on CSII with a low risk of false positive if we consider a threshold of 0.3 mmole/l for ketone bodies.

Nocturnal hypoglycemia: clinical manifestations and therapeutic strategies toward prevention

OBJECTIVE

To review the features of nocturnal hypoglycemia and various preventive strategies.

METHODS

We discuss the physiologic changes, the potential precipitating factors, the immediate and long-term effects, and the currently available options for treatment of nocturnal hypoglycemia in patients with diabetes.

RESULTS

Nocturnal hypoglycemia is common in patients with type 1 diabetes and is usually asymptomatic. Nocturnal hyperinsulinemia frequently occurs with insulin therapy, and although blood glucose levels are often low during sleep, they are seldom measured routinely. Almost 50% of all episodes of severe hypoglycemia occur at night during sleep. Such episodes can cause convulsions and coma and have been implicated as a precipitating factor in cardiac arrhythmias resulting in sudden death--the "dead-in-bed syndrome." Nocturnal hypoglycemia seems to have no immediate detrimental effect on cognitive function; however, on the following day, mood and well-being may be adversely affected. Recurrent exposure to nocturnal hypoglycemia may impair cognitive function; other substantial long-term morbidity includes the development of acquired hypoglycemia syndromes, such as impaired awareness of hypoglycemia, through the putative effect of unsuspected recurrent episodes of nocturnal hypoglycemia.

CONCLUSION

In efforts to decrease the risk of nocturnal hypoglycemic episodes, various strategies can be used to minimize the nocturnal hyperinsulinemia that is associated with many insulin replacement regimens. Regular blood glucose monitoring (particularly at bedtime), the ingestion of appropriate bedtime snacks, and the utilization of short- and long-acting insulin analogues may all help to prevent or minimize the frequency of nocturnal hypoglycemia.

Hypoglycemia in Type 1 Diabetes Mellitus

Spontaneous hypoglycemia is uncommon in the general (nondiabetic) population, but iatrogenic hypoglycemia is rife in patients with type 1 diabetes mellitus, among whom hypoglycemia constitutes a barrier to optimal glycemic control. The obligate dependence on exogenous insulin, together with the current imperfection in insulin therapies, generates degrees of blood glucose fluctuations that often exceed physiological boundaries in these patients. Downward swings in blood glucose levels, if sustained, result in hypoglycemia and significant morbidity and mortality. Hypoglycemia in type 1 diabetes indicates an imbalance between caloric supply and glucose use in response to insulin or exercise. Counterregulatory mechanisms that auto-correct iatrogenic hypoglycemia often become progressively impaired in these patients. This defective counterregulation, together with the imperfections in insulin delivery, set the stage for significant morbidity from iatrogenic hypoglycemia. Recurrent episodes of iatrogenic hypoglycemia induce a state of hypoglycemia unawareness and defective counterregulation, which defines the syndrome of hypoglycemia-associated autonomic failure (HAAF). The reduced awareness of, and counterregulatory responses to, hypoglycemia in patients with HAAF lead to worsening episodes of severe hypoglycemia. Approaches to the prevention of hypoglycemia include glucose monitoring, patient education, meal planning, and medication adjustment. In patients with HAAF, scrupulous avoidance of iatrogenic hypoglycemia may restore the symptomatic and counterregulatory responses to hypoglycemia. Behavioral training focusing on recognition of the more subtle symptoms and signs of evolving hypoglycemia may be beneficial to some patients with HAAF. A methodical search for the pattern and etiology of iatrogenic hypoglycemia is a prerequisite for the identification of the best preventive approach. With proper education, patients with type 1 diabetes and their physicians can learn to prevent or minimize the risk of hypoglycemia while pursuing excellence in glycemic control.

Hypoglycemia in children with type 1 diabetes: current issues and controversies

Hypoglycemia is a common complication of insulin therapy, particularly in the young. For children and adolescents with diabetes, the risk of hypoglycemia may not only prevent optimal glycemic control but can also add significantly to the psychosocial burden of the disease. Recently, surveys employing prospective monitoring techniques have allowed more precise information to be gained about rates of hypoglycemia, its clinical associations, and the impact of new therapies and technologies. A number of reports have estimated rates of hypoglycemic comas and convulsions to be approximately 20 events per 100 patient years in children on current conventional therapy. There is evidence that the introduction of new analog short- and longer-acting insulins and the more widespread use of continuous subcutaneous infusion therapies may allow improvements in glycemic control to occur without the usual increased rate of severe hypoglycemic episodes. The use of glucose sensor technology has brought into focus the widespread occurrence of asymptomatic hypoglycemia. Asymptomatic hypoglycemia has long been recognized, particularly at night, when the combination of excessive insulin action and suppressed counter-regulatory hormone responses put children at special risk of hypoglycemia. Hypoglycemia unawareness is common in the young and is associated with an increased risk of severe hypoglycemia. Whether episodes of severe hypoglycemia have long-term consequences is controversial. Early studies suggesting that the developing brain is sensitive to permanent neurological damage as a result of hypoglycemia have not been confirmed in more recent reports. Many studies have not found convincing evidence of neurological sequelae of the hypoglycemic events that are an inevitable complication of insulin therapy. The question, however, remains under active investigation. Continued prospective monitoring of hypoglycemia rates and consequences has become an essential component of diabetes management.