A Prospective Study of Insulin Infusion Set Use for up to 7 Days: Early Replacement Reasons and Impact on Glycemic Control.

Background: There is limited evidence supporting a replacement interval of infusion sets for continuous subcutaneous insulin infusion (CSII). The aim of this study was to investigate if steel and soft cannula infusion sets can be used in CSII therapy for up to 7 days without negative impact on infusion sites or glycemic control. Methods: The insulin infusion sets YpsoPump® Orbit®micro (steel needle) and YpsoPump® Orbit®soft (soft cannula) were each used for up to 7 days by 40 adult subjects with CSII. Each subject used both infusion set types twice. Early replacement reasons were documented and glycemic control was monitored. Results: Of 160 inserted insulin infusion sets, 66% were used for 7 days with no obvious difference between steel and soft infusion sets. The mean wearing time was 6.2 ± 1.5 days. Main reasons for early infusion set replacements were occlusions (19%), plaster issues (4%), and accidental pull-out (4%). Comparing glycemic control during day 1-3 and 1-7, mean glucose was 146 ± 21 mg/dL versus 148 ± 18 mg/dL, coefficient of variation was 34% ± 7% versus 33% ± 5%, and insulin dose was 40 ± 11 U versus 41 ± 11 U. Only mild and nonserious infusion site reactions occurred. Conclusions: In this study, 7 days indwelling time of insulin infusion sets did not show a clinically relevant impact on glycemic control or insulin requirements and the infectious risk appeared to be low. The replacement interval of infusion sets may be individualized beyond the currently labeled maximum use duration.

First User Experiences With a Novel Touchscreen-Based Insulin Pump System in Daily Life of Patients With Type 1 Diabetes Experienced in Insulin Pump Therapy.

INTRODUCTION: A new insulin pump system was tested under everyday conditions for user evaluation and safety assessment prior to its launch in Europe. This insulin pump is focused on easy handling and uses prefilled cartridges. METHODS: The pump system was used by 35 adult subjects with type 1 diabetes, experienced in insulin pump therapy, under everyday conditions for approximately one month each. All subjects rated various aspects of the system after home use; technical issues and safety parameters were assessed throughout the study. RESULTS: All 35 subjects completed the study as planned and used the system for a total of 1013 days. After home use, 74% of the subjects were very satisfied or quite satisfied with the new pump. The subjects confirmed that the system is easy to use, especially considering general handling, bolus delivery and basal rate settings, infusion set, and cartridge change. Potential for improvements was seen in the touchscreen, warnings and alarms, the blind bolus function, the availability of a bolus calculator (was not available at time of study), and the cartridge size as rated by the study participants. Safety analysis did not raise any concerns for the use of this system. CONCLUSION: The majority of the users testing the system were satisfied with the novel insulin pump system and the system was safe for use under everyday conditions by this study population.

Clinical performance of a device that applies local heat to the insulin infusion site: a crossover study.

BACKGROUND: Fast-acting insulin analogs have been available since 1996. The absorption rate of these insulins is still too slow to mimic the physiological insulin action in healthy subjects. This study investigates the clinical performance of InsuPatch™, a local skin-heating device, on postprandial glucose excursion. METHODS: Twenty-four type 1 diabetes mellitus subjects on continuous subcutaneous insulin infusion were included in this crossover study [10 male, 14 female, age: 43.5 ± 11.3 years, diabetes duration: 18.3 ± 10.5 years, glycosylated hemoglobin: 7.4 ± 0.8%, body mass index: 25.0 ± 3.0 kg/m(2) (mean ± standard deviation)]. The impact of local skin heating was measured by dividing the two-hour area under the curve by integration time (AUC/t(120)) for blood glucose (BG) above baseline after two standardized breakfast and dinner meal pairs (with and without heating) per subject. For the first breakfast pair, venous insulin concentration was also measured. RESULTS: A significant reduction was found for the AUC/t(120) after breakfast and after dinner meals (42 breakfast meal pairs, AUC/t(120) not heated 66.4 ± 32.8 mg/dl vs heated 56.8 ± 34.0 mg/dl, p = .017; 38 dinner meal pairs, AUC/t(120) not heated 30.8 ± 31.0 mg/dl vs heated 18.4 ± 23.9 mg/dl, p = .0028). The maximum venous insulin concentration with heating was 27% higher than without heating (n = 23). The number of hypoglycemic events on days with heating (n = 9) was similar to the number of days without heating (n = 13). CONCLUSIONS: Local heating of the skin around the infusion site significantly reduced postprandial BG by enhancing insulin absorption. The heating device was well tolerated, and it could facilitate development of closed-loop systems.

Multicenter user evaluation of ACCU-CHEK® Combo, an integrated system for continuous subcutaneous insulin infusion.

BACKGROUND: The aim of this study was to evaluate a newly developed system for insulin delivery incorporating a multifunctional blood glucose meter and a remotely controlled insulin pump (ACCU-CHEK® Combo system) in established pump users with type 1 diabetes. The technology was assessed both from device performance and subject usability perspectives. METHOD: A multicenter, prospective, single group study was carried out in five centers in the Netherlands and four centers in the United Kingdom for more than 6 months. The study was divided into two phases: Phase 1 (4 weeks) for device validation purposes and phase 2 (22 weeks) to observe the impact of the system on metabolic control, patient satisfaction [using the Diabetes Treatment Satisfaction Questionnaire (DTSQ)] and device safety. RESULTS: Eighty subjects completed the planned study period. There were no unexpected device errors. Treatment satisfaction was high at baseline and further increased to study end (DTSQ change version: sum score, 10.6±7.2; scale score range, -18 to +18, p<0.0001). Hemoglobin A1c improved continuously over time, from 7.9% (±0.9%) to 7.7% (±0.8%) at month 3 (p<0.001) and 7.6% (±0.8%) at month 6 (p<0.0001). The frequency of severe hypoglycemia was 0.08 per patient years. There was no case of ketoacidosis. CONCLUSIONS: The new system was evaluated by experienced continuous subcutaneous insulin infusion users as safe in daily practice and associated with favorable treatment satisfaction and a modest improvement in glycemic control.

Functional characterization of the new human GABA(A) receptor mutation beta3(R192H).

We screened 124 individuals for single nucleotide polymorphisms of the alpha1, beta3 and gamma2 genes of the GABA(A) receptor in the regions corresponding to the ligand-binding domains on the protein level. In a patient with chronic insomnia, a missense mutation was found in the gene of the beta3 subunit. This mutation results in the substitution of the amino acid residue arginine for histidine in position 192 (beta3(R192H)). The patient was found to be heterozygous for this mutation. Functional analysis of human alpha1beta3(R192H)gamma2S GABA(A) receptors using ultra fast perfusion techniques revealed a slower rate of the fast phase of desensitization compared with alpha1beta3gamma2S GABA(A) receptors. Additionally, current deactivation [a major determinant of inhibitory postsynaptic current (IPSC) duration] was faster in the mutated receptors. This raises the possibility of decreased GABAergic inhibition contributing to insomnia, as some members of the patient's family also suffer from insomnia. The mutation beta3(R192H) might, therefore, be linked to this condition. The intron/exon boundaries of the alpha1 subunit gene were also established and three additional variants were found in the alpha1 and beta3 genes.