A physiological study of the effect of alpha-melanocyte stimulating hormone (alpha-MSH) on glucose tolerance in people with type 1 diabetes

INTERVENTION: 10ug/ml alpha‐MSH in saline administered via intravenous infusion at 1500ng/kg/hr, commencing at time ‐30 minutes and continued until time 180 minutes. At time 0 minutes, participants will consume a drink containing 75g glucose within 5 minutes. The intravenous infusion and glucose challenge will be supervised by a research nurse. The wash out period between the intervention and comparator treatments will be at least 2 days and no longer than 6 weeks. Participants will be asked to administer half of the usual insulin dose they would normally take to cover the glucose load immediately prior to consuming the glucose drink (time 0 minutes), or if they use an insulin pump, asked to set the pump to a temporary basal rate immediately prior to the infusion (‐30 minutes). The study doctor will consult with each participant to formulate a plan for insulin dosing before and during the oral glucose tolerance test. CONDITION: Metabolic and Endocrine ‐ Diabetes Type 1 Diabetes; ; Type 1 Diabetes PRIMARY OUTCOME: Two‐hour area under the curve blood plasma glucose concentration following 75g oral glucose commencing at time 0 minutes and calculated using measures collected at 0, 15, 30, 60, 90 and 120 minutes.[0, 15, 30, 60, 90 and 120 minutes relative to consumption of the glucose drink.] SECONDARY OUTCOME: Adverse events[At ‐30, 0, 30, 60, 90, 120 and 180 minutes relative to consumption of the glucose drink, participants will be asked whether they are feeling any tiredness, nausea or flushing. Participants will additionally be observed throughout the 3.5 hour infusion to monitor for adverse events, as well as for 30 minutes before commencing the infusion and 30 minutes after stopping the infusion. Within 48 hours of completing a treatment visit, a research nurse will call participants to enquire about any adverse events.] Blood plasma alpha‐MSH concentrations at ‐30, 0, 15, 30, 60, 90, 120 and 180 minutes.[‐30, 0, 15, 30, 60, 90, 120 and 180 minutes relative to consumption of the glucose drink.] Blood plasma glucagon concentrations at ‐30, 0, 15, 30, 60, 90, 120 and 180 minutes.[‐30, 0, 15, 30, 60, 90, 120 and 180 minutes relative to consumption of the glucose drink.] Blood plasma glucose concentrations at ‐30 and 180 minutes.[‐30 minutes and 180 minutes relative to consumption of the glucose drink.] Blood serum c‐peptide concentrations at ‐30, 0, 15, 30, 60, 90, 120 and 180 minutes.[‐30, 0, 15, 30, 60, 90, 120 and 180 minutes relative to consumption of the glucose drink.] Blood serum insulin concentrations at ‐30, 0, 15, 30, 60, 90, 120 and 180 minutes.[‐30, 0, 15, 30, 60, 90, 120 and 180 minutes relative to consumption of the glucose drink.] INCLUSION CRITERIA: Type 1 diabetes with a confirmed diagnosis of at least 3 years' duration and a plasma or serum c‐peptide of less than 0.1 nM. BMI equal or greater than 18 and less than 30kg/m2, with a stable body weight for at least three months prior to enrolment. Be able to read and understand the written information about the study and provide written consent to participate in it.