Novel insulin delivery profiles for mixed meals for sensor-augmented pump and closed-loop artificial pancreas therapy for type 1 diabetes mellitus

Maintaining euglycemia for people with type 1 diabetes is highly challenging, and variations in glucose absorption rates with meal composition require meal type specific insulin delivery profiles for optimal blood glucose control. Traditional basal/bolus therapy is not fully optimized for meals of varied fat contents. Thus, regimens for low- and high-fat meals were developed to improve current insulin pump therapy. Simulations of meals with varied fat content demonstrably replicated published data. Subsequently, an insulin profile library with optimized delivery regimens under open and closed loop for various meal compositions was constructed using particle swarm optimization. Calculations showed that the optimal basal bolus insulin profiles for low-fat meals comprise a normal bolus or a short wave. The preferred delivery for high-fat meals is typically biphasic, but can extend to multiple phases depending on meal characteristics. Results also revealed that patients that are highly sensitive to insulin could benefit from biphasic deliveries. Preliminary investigations of the optimal closed-loop regimens also display bi- or multiphasic patterns for high-fat meals. The novel insulin delivery profiles present new waveforms that provide better control of postprandial glucose excursions than existing schemes. Furthermore, the proposed novel regimens are also more or similarly robust to uncertainties in meal parameter estimates, with the closed-loop schemes demonstrating superior performance and robustness.

Bolus calculator and wirelessly communicated blood glucose measurement effectively reduce hypoglycaemia in type 1 diabetic children - randomized controlled trial

BACKGROUND

The aim of this study was to assess the effect of bolus calculator function and wireless communication between insulin pump and blood glucose metre on metabolic control in children with type 1 diabetes, treated with insulin pumps.

METHODS

In this randomized, controlled, 12-week trial, 156 patients, aged 12.9 ± 2.6 years, with a history of diabetes of 5.1 ± 3.3 years and glycated haemoglobin values of 7.3 ± 1.2% (56.3 ± 13.44 mmol/mol) were included. Children were assigned to one of three arms: group A, subjects using bolus calculator and wireless communication between insulin pump and blood glucose metre; group B, subjects using bolus calculator without communication between the devices and group C, control group. Devices were downloaded at 0, 6 and 12 weeks.

RESULTS

There were statistically fewer episodes of hypoglycaemia in children using bolus calculator compared with the control group: A versus C (3.8 ± 3.1 versus 7.8 ± 5.13 episodes/2 weeks, respectively, p < 0.0001); B versus C (3.6 ± 3.3 versus 7.8 ± 5.1 episodes/2 weeks, respectively, p < 0.0001). Patients in group A used bolus calculator function significantly more frequently than patients in group B (4.9 ± 3.4 versus 2.5 ± 2.9 times/24 h, respectively, p = 0.0006). No significant differences in glycated haemoglobin levels were found between the experimental and the control groups: group A versus C (p = 0.699). The use of bolus calculator did not influence post-prandial glycaemia, body mass index-SD score or insulin/kg/24 h.

CONCLUSIONS

Bolus calculator use reduces hypoglycaemic episodes independently of communication between insulin pump and blood glucose metre. Wireless communication between devices results in more frequent bolus calculator use.

Insulin pump therapy is equally effective and safe in elderly and young type 1 diabetes patients

OBJECTIVES

It is generally accepted that in adult type 1 diabetes patients (T1D) continuous subcutaneous insulin infusion (CSII) via a personal pump is more effective than the multiple daily injections (MDI) model. However, it is not clear whether all age groups of adult T1D patients may equally benefit from CSII therapy. We aimed to compare the glycemic control and use of selected pump tools in T1D subjects using CSII over the age of 50 (50+ T1D) with patients younger than 50 years of age.

METHODS

The last available insulin pump/blood glucose meter downloads and last available HbA1c levels of 124 adult T1D subjects using CSII were reviewed. We divided our cohort into two subgroups: 50+ T1D patients (n = 13) and younger patients (n = 111).

RESULTS

There were no differences in glycemic control achieved with CSII treatment in 50+ T1D patients vs. younger subjects. HbA1c levels were 7.01 ± 0.67% and 7.34 ± 1.24% (p = 0.46), and the mean glycemia based on glucometer downloads was 141.8 ± 17.7 mg/dl and 150.8 ± 35.7 mg/dl (p = 0.69), respectively. Also, there were no differences with respect to the use of important personal pump options and tools.

CONCLUSION

In conclusion, insulin pump therapy appears to be effective and safe in T1D patients regardless of age.