Effects of Acute Intake of Caffeinated Beverages in Type 1 Diabetes (REDBULL)

Effects of Acute Intake of Caffeine Enhanced Energy Drinks on Blood Glucose, Some Physiological Parameters and Cognitive Performance in Patients With Type 1 Diabetes

The aim of this pilot study is to determine the impact of caffeine-enhanced energy drinks on blood glucose excursion on heart rate, blood pressure, cardiac output and cognitive performance in patients with type 1 diabetes. Knowledge acquired may inform a wider study of the impact of these drinks. This is a randomised, cross over blinded study in which all participants will participate in the 3 arms of the study. The study will consist of 3 phases, each lasting 3 days. A different study drink will be administered during each phase. There will be an initial screening visit and a pre- study visit before each study phase. Each participant will make 10 visits to the research centre. There will be a week wash out period between each study phase. Prior to each study phase, there will be a 3 day caffeine and alcohol abstinence run-in period. Study drinks will be matched for taste and volume (as far as possible) and will be administered by the use of opaque cups, lids and straws to enable double-blind randomisation for both researcher and participants. Administration of the study drink to participants will be based on Latin squares to provide a balanced treatment order. During the 3 days study period; participants will be required to abstain from all other caffeine containing beverages or confectioneries. The secondary aim is to determine if tolerance to cardiovascular effects of caffeine-enhanced energy drinks is developed following acute short term ingestion.

Regular caffeine enhanced energy drink (containing 240mg caffeine & 84g glucose) e.g. regular red bull cans (x3)

The effects on certain mood states, e.g. energetic arousal, tense arousal and hedonic tone following the consumption of caffeinated energy drinks in comparison with caffeine free glucose in patients with type 1 diabetes

Inclusion Criteria: Male and female adults aged ≥18 years Confirmed diagnosis of Type 1 diabetes of more than one year duration Participants who use multiple daily injections of basal and meal-time analogue insulin. Ability to perform daily finger stick measurements of blood glucose levels Adequate contraceptive control Provision of informed consent Exclusion Criteria: Hypoglycaemia unawareness Coronary heart disease Cardiac arrhythmia Structural heart lesions, Autonomic neuropathy Psychiatry illness, Epilepsy Migraine Caffeine intolerance Unable to provide informed consent