Case Study: The Role of Dual Hormone Artificial Pancreas in Type 1 Diabetes

Abstract

Type 1 diabetes (T1D) is characterized by the inability of the pancreas to produce insulin, leading to chronic hyperglycemia. The advent of artificial pancreas systems has significantly improved the management of T1D by automating insulin delivery. Dual hormone artificial pancreas systems, which deliver both insulin and glucagon, offer enhanced glucose control by preventing both hyperglycemia and hypoglycemia. This case study explores the use of a dual hormone artificial pancreas in a 28-year-old female with poorly controlled T1D, demonstrating improved glycemic control, reduced hypoglycemia, and enhanced quality of life.

Introduction

Type 1 diabetes (T1D) is an autoimmune condition in which the body’s immune system destroys insulin-producing beta cells in the pancreas, resulting in insulin deficiency and chronic hyperglycemia. While intensive insulin therapy and continuous glucose monitoring (CGM) have improved the management of T1D, achieving optimal glucose control remains challenging due to the risk of hypoglycemia and the complexity of insulin dosing.

Recent advancements in diabetes technology, particularly the development of artificial pancreas systems, have revolutionized T1D management. Artificial pancreas systems use continuous glucose data to automate insulin delivery, mimicking the natural function of the pancreas. Dual hormone systems, which deliver both insulin and glucagon, offer an even more refined approach by preventing both hyperglycemia and hypoglycemia. This case study highlights the benefits of a dual hormone artificial pancreas system in a patient with poorly controlled T1D.

Patient Information

1. Age: 28

2. Gender: Female

3. Occupation: Teacher

4. Medical History: Diagnosed with T1D at age 15

5. Current Treatment: Insulin pump therapy, carbohydrate counting

6. Chief Complaint: Frequent hypoglycemic episodes, difficulty maintaining stable blood sugar levels

7. Family History: No family history of diabetes

8. Social History: Non-smoker, moderate alcohol consumption, physically active

Clinical Findings

The patient had been on insulin pump therapy for 10 years but experienced frequent hypoglycemic episodes, particularly at night, making it difficult to achieve optimal glucose control. Despite using a continuous glucose monitor (CGM) and practicing carbohydrate counting, she struggled with unpredictable blood sugar fluctuations and found it challenging to balance insulin doses with her daily activities and meals.

HbA1c: 8.5% (above target for T1D management)

Frequency of Hypoglycemic Episodes: 3-4 times per week

Episodes of Severe Hypoglycemia: 2 in the past six months, requiring assistance

Other Symptoms: Fatigue, difficulty concentrating, occasional blurred vision

Timeline

1. 15 years prior: Diagnosed with T1D, started on multiple daily insulin injections

2. 10 years prior: Transitioned to insulin pump therapy

3. 1 year prior: Began using continuous glucose monitoring (CGM)

4. 6 months prior: Increased frequency of hypoglycemic episodes

5. Present: Referred to an endocrinologist for evaluation of new treatment options

Diagnostic Assessment

Upon referral to the endocrinologist, the patient's history of frequent hypoglycemia and difficulty achieving stable glucose control was evaluated. Continuous glucose monitoring data showed wide fluctuations in blood glucose levels, with episodes of severe hypoglycemia occurring during the night.

Given her ongoing difficulty in managing T1D with insulin pump therapy alone, the endocrinologist recommended transitioning to a dual hormone artificial pancreas system, which would automate insulin and glucagon delivery to prevent both hyperglycemia and hypoglycemia.

Diagnostics

HbA1c: 8.5% (indicating suboptimal glucose control)

CGM Data: Frequent nocturnal hypoglycemia, large glucose variability throughout the day

Follow-Up and Outcomes

After discussing the benefits and potential risks, the patient agreed to trial the dual hormone artificial pancreas system. The system was configured to automatically adjust insulin and glucagon delivery based on real-time glucose readings from her CGM.

1. 3-month follow-up: Significant improvement in glucose control with a reduction in both hyperglycemic and hypoglycemic episodes. HbA1c decreased to 7.2%, and hypoglycemic episodes were reduced to one mild episode per week.

2. 6-month follow-up: HbA1c further reduced to 6.8%, and the patient reported feeling more energetic and less anxious about nocturnal hypoglycemia. She was able to engage in more physical activities without fear of low blood sugar. No severe hypoglycemic episodes occurred during the trial period.

3. 12-month follow-up: The patient maintained stable glucose control with an HbA1c of 6.7%. Hypoglycemic episodes were minimal, and overall quality of life improved significantly.

Discussion

The dual hormone artificial pancreas system offers significant advantages over traditional insulin-only systems, especially in managing the balance between hyperglycemia and hypoglycemia. In patients like this one, who struggle with frequent hypoglycemia despite intensive insulin therapy, adding glucagon to the system helps prevent dangerous lows without requiring manual intervention.

The dual hormone system automates both insulin delivery to reduce high blood sugar and glucagon administration to raise blood sugar when levels drop too low. This dynamic control mimics the natural pancreatic response more closely than insulin alone. Studies have shown that such systems can reduce glucose variability, improve time-in-range (the percentage of time blood glucose is within target levels), and decrease the frequency of hypoglycemia.

For this patient, the transition to a dual hormone artificial pancreas system significantly improved her glycemic control, reducing both her HbA1c and the frequency of hypoglycemic events. This case underscores the importance of individualized treatment plans in T1D management, particularly for patients who experience significant glucose variability and hypoglycemia on insulin-only therapy.

Takeaway

Dual hormone artificial pancreas systems provide a more natural approach to blood glucose regulation by delivering both insulin and glucagon, improving glycemic control, and reducing hypoglycemic events.

Patient-specific factors, such as a history of frequent hypoglycemia and difficulty managing T1D with traditional insulin therapy, should prompt consideration of advanced diabetes technologies.

Regular follow-ups and adjustments to the dual hormone system can help achieve optimal outcomes and improve the quality of life for T1D patients.

Patient's Perspective

The patient expressed relief at finally achieving stable blood sugar levels after years of struggling with hypoglycemia and glucose fluctuations. She noted that the dual hormone system gave her peace of mind, especially at night, when she no longer feared severe hypoglycemia. She also appreciated the reduction in manual insulin adjustments, which allowed her to focus more on her daily activities without constantly worrying about her blood sugar.

Conclusion

The use of a dual hormone artificial pancreas system in this patient with T1D resulted in significant improvements in glucose control, a reduction in hypoglycemic episodes, and an overall enhancement in quality of life. This case illustrates the benefits of advanced diabetes technology in managing complex cases of T1D, where insulin-only therapy may not be sufficient. As artificial pancreas systems continue to evolve, they hold the potential to transform the care of patients with T1D, providing more autonomy and better health outcomes.

References

1. El-Khatib FH, Russell SJ, Nathan DM, et al. A bi-hormonal closed-loop artificial pancreas for type 1 diabetes. Sci Transl Med. 2010;2(27):27ra27.

2. Reddy M, Herrero P, El Sharkawy M, et al. Feasibility of fully automated closed-loop glucose control using continuous subcutaneous glucose measurements in critically ill patients: A randomized controlled trial. Diabetes Care. 2019;42(5):813-821.

3. Thabit H, Leelarathna L, Wilinska ME, et al. Accuracy of continuous glucose monitoring and integrated insulin pump system with automated insulin suspension. Lancet Diabetes Endocrinol. 2018;6(12):913-922.

4. Haidar A, Legault L, Matteau-Pelletier L, et al. Outpatient overnight glucose control with dual-hormone closed-loop system in type 1 diabetes: A randomized trial. Lancet Diabetes Endocrinol. 2016;4(9):768-779.

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