Optimal time of mealtime insulin administration in people with type 1 diabetes

INTERVENTION: Ten type 1 diabetics who had been on CSII for at least six months were included in the study. On the day before the first test meal, patients received a subcutaneous CGM sensor (Medtronic CGMS SofSensor) during a visit to the outpatient clinic and were instructed to calibrate the sensor at home according to the manufacturer?s specifications. The next day at 08:00 am, patients reported on an empty stomach to the clinical research unit and were admitted. Patients received an intravenous catheter for blood collection. Before the start of the daily study protocol blood glucose was measured by finger prick. If blood glucose was between 3.0 mmol/L and 7.8 mmol/L, the study protocol would commence immediately. If the blood glucose was too high, intravenous insulin aspart was administered. If blood glucose had been corrected to acceptable parameters and if these values remained stable (excursions < 0.6mmol/L) over a period of 1 hour, the study protocol commenced. Patients were randomized on each study day by means of opaque, sealed envelopes which were sequentially numbered, between insulin bolus administration at three strata; ‐30, ‐15 or 0 minutes before the meal. Each patient was provided with a meal that was comparable to their regular morning meal, the meal for one individual patient did not differ over study days. The first hour before the meal blood was sampled every 15 minutes, the first 2 hours after the meal every 10 minutes and the third and fourth hour after the meal every 20 minutes. Blood samples were collected in 2cc sodium fluoride tubes for determination of blood glucose. The insulin bolus was administered by the patients according to their own calculation of carbohydrates in the meal (at this point estimated to be between 4 and 12 IU per meal, depending on the patient and their respective meals). After the test meal and blood collection, patients would go home continuing to wear the CGM sensor and reported back to the clinical research unit the next day t CONDITION: Type 1 diabetes and postprandial glycemic conditions. ; Nutritional, Metabolic, Endocrine ; Insulin‐dependent diabetes mellitus PRIMARY OUTCOME: All outcomes in this study are outcomes derived from the postprandial glucose curve, and as such are a measure of postprandial glucose control on the three study days until 5 hours postprandially. SECONDARY OUTCOME: 1. Continuous Glucose Monitoring (CGM) values; 2. Number and duration of hypoglycemias; 3. Maximum swing of blood‐glucose levels; 4. Highest blood glucose levels; 5. Lowest blood glucose levels; 6. Time spent in hyperglycemia INCLUSION CRITERIA: 1. Men or women aged from 18 to 75 years 2. Type 1 diabetes according to the WHO definition 3. Treated with insulin for at least 2 years and by Continuous Subcutaneous Insulin Infusion (CSII) for at least 6 months 4. Body mass index (BMI) < 35 kg/m2 5. Written informed consent