Anasarca in Newly Diagnosed Type 1 Diabetes: Review of the Pathophysiology of Insulin Edema

Insulin edema after initiation of hybrid closed-loop insulin pump therapy with continuous glucose monitoring: a case report

BACKGROUND

Insulin edema is a rare complication which can present after initiation or intensification of insulin therapy in people with diabetes. Initiation of closed-loop hybrid insulin pump therapy can result in rapid improvement in glycemic control for people with diabetes. We present a case in which transition to a closed-loop hybrid insulin pump system, followed by significant improvement in glycemic control, led to development of insulin edema in a person with type 1 diabetes.

CASE PRESENTATION

We present a 51-year-old woman with type 1 diabetes of 16 years duration, on insulin pump therapy for more than 10 years, who presented for follow-up 7 weeks after transitioning to a hybrid closed-loop insulin pump system with continuous glucose monitoring (CGM). She complained of weight gain and bilateral lower extremity edema which had started two weeks after the change in pump modality. Laboratory studies and echocardiogram did not reveal any etiology of the acute edema. HbA1c was 3.3% lower than the previous measurement 15 weeks earlier, and there was a significant increase in the daily total insulin dose. With exclusion of other causes of acute edema, the patient was diagnosed with insulin edema and started on hydrochlorothiazide. On follow up, her lower extremity edema significantly improved although her weight did not return to baseline.

CONCLUSION

To our knowledge, this is the first case of insulin edema reported in a person with type 1 diabetes using CGM and a hybrid closed-loop insulin pump system. The increase in total daily insulin dose, rapid improvement of glycemic control, and lack of hypoglycemic episodes were important factors to consider in evaluation of this case. Use of hybrid closed-loop systems can help achieve rapid improvement in glycemic control in people with diabetes. This case suggests that consideration should be given to adjusting initial blood glucose targets when starting these remarkable new technologies in people with baseline poor glycemic control.

Insulin Edema Syndrome due to Rapid Glucose Correction in a Diabetic Patient

Edema resulting from the initiation of insulin therapy or intensification of glycemic control is a rare and under-recognized complication. In this report, we present a case of a 46-year-old patient with insulin-dependent diabetes mellitus (IDDM) who avoided insulin treatment due to associated peripheral edema. Though rare, this phenomenon is typically seen in patients with elevated glucose levels who are initiated on insulin treatment, resulting in rapid correction and tight control of glucose levels. The diagnosis of insulin-induced edema is made after other causes of acute edema are ruled out. Furthermore, in this case report, we will also discuss the postulated mechanisms for the edema-causing property of insulin.

Insulin oedema in type 2 diabetes mellitus: A case report

Insulin oedema is a rare condition that may occur after the initiation or rapid intensification of insulin therapy in patients with long-standing hyperglycaemia, commonly with type 1 diabetes mellitus (DM). We reported a case of insulin oedema in a patient with type 2 DM who presented with swelling of the extremities and weight gain of 3 kg 1 week after insulin initiation. A course of furosemide was administered, but no significant immediate improvement was observed; however, the lower limb swelling resolved spontaneously after 3 months of follow-up. The patient also achieved adequate diabetic control with insulin, as shown by the reduction of her HbA1c from 10.7% to 6.9% over 6 months. Insulin oedema is a diagnosis of exclusion after ruling out other differential diagnoses, such as cardiac, renal, or liver failure. Although insulin oedema carries with it a good prognosis, physicians should be aware of the condition to avoid misdiagnosis.

Insulin-Induced Edema in a Patient with Type 2 Diabetes Mellitus

Patient: Female, 35-year-old

Final Diagnosis: Diabetes mellitus type 2

Symptoms: Edema of lower limbs • edema of the face

Medication: Insulin glargine

Clinical Procedure: —

Specialty: Endocrinology and Metabolic

Insulin Edema With Use of U-500 Regular Insulin in a Hybrid Closed-Loop Insulin Pump

Insulin edema is a rare complication of insulin therapy which has been described in known or newly diagnosed people with diabetes, following initiation or intensification of insulin treatment. Here we present a 63-year-old man with complaints of weight gain, shortness of breath, and lower extremity edema starting two weeks after the change of his insulin pump to the hybrid closed-loop insulin pump system and substitution of U-100 aspart insulin with U-500 regular insulin. Laboratory studies, imaging, and electrocardiogram (EKG) were performed to evaluate the cause of acute edema and were all normal. Hemoglobin A1C showed remarkable improvement after the pump change and the insulin pump download showed a significant increase in the amount of total daily insulin administered. With the exclusion of other causes of acute edema, the patient was diagnosed with insulin edema. He was started on spironolactone 50 mg/daily and showed a desirable improvement of edema on follow-up. 

This case shows that although the use of the hybrid insulin-pump system helps to obtain better control of diabetes in many patients, the rapid improvement in glycemic control may precipitate the development of insulin edema. Furthermore, the use of high concentration insulin in insulin pumps is off-label and their use might increase the rate of complications of insulin therapy including insulin edema.