For diabetics with gastroparesis, unpredictable gastric emptying rates and uncertainties in nutrient absorption can lead to difficulties in managing glycemia. The utility of continuous glucose monitoring (CGM), which quantifies real time glucose excursions, in planning periprandial insulin dosing for diabetic patients with gastroparesis has not been explored. The Safety, Feasibility, and Potential Efficacy of Continuous Glucose Monitoring and Insulin Pump Therapy in Diabetic Gastroparesis (GLUMIT-DG) study is a multicenter, uncontrolled clinical trial that was established by the Gastroparesis Clinical Research Consortium (GpCRC) to assess the safety and utility of CGM in guiding insulin pump therapy in patients with type 1 and type 2 diabetes and gastroparesis.

Individuals with symptoms of gastroparesis, a Gastroparesis Cardinal Symptom Index (GCSI) score of 18, and diabetes for at least 2 years are enrolled in the study. Participants are treated using a combination of CGM and insulin pump therapy. The primary outcome measure, the frequency of mild and moderate (glucose level < 70 mg/dL) and severe hypoglycemic episodes while undergoing therapy, is assessed at 12 and 24-week follow-up visits. CGM data are related to finger stick levels and HbA1c values to test comparability of CGM and finger stick values. The efficacy of CGM-guided insulin pump therapy on symptoms of gastroparesis, quality of life, satiety, gastric myoelectrical activity, and autonomic function are also evaluated as a secondary outcome measures.

The study aimed to evaluate the safety and efficacy of continuous glucose monitoring (CGMS) in conjunction with an insulin pump to improve glycemic control for treatment of type 1 and type 2 diabetic patients with gastroparesis.

The primary outcome measure, the frequency of mild and moderate (glucose level < 70 mg/dL) and severe hypoglycemic episodes while undergoing therapy, is assessed at 12 and 24-week follow-up visits. The efficacy of CGM-guided insulin pump therapy on symptoms of gastroparesis, quality of life, satiety, gastric myoelectrical activity, and autonomic function are also evaluated as a secondary outcome measures.

Individuals between the ages of 18-70 years who met the following criteria were eligible for the study:

• Type 1 or Type 2 diabetes mellitus for at least 2 years
• Symptoms of gastroparesis for at least 1 year prior to registration
• Gastroparesis Cardinal Symptom Index (GCSI) score of 18
• Delayed gastric emptying on gastric scintigraphy within 1 year of registration, defined as greater than 60% retention at 2 hours or greater than 10% retention at 4 hours
• Hemoglobin A1c of at least 8.0% at registration regardless of current therapy
• Normal upper endoscopy within 1 year of registration
• No clinical or imaging evidence of obstruction
• Successful mastering use of GMS during the run-in period

Preliminary analysis has shown excellent comparability between CGM and finger stick values (random Bland-Altman plot, 95% limits of agreement = -55 to +52 mg/dL, and Pearson's correlation = 0.95 [p<0.001]).