The Role of the Adrenergic System in Hypoglycaemia Induced Inflammatory Response in People With Type 1 Diabetes and People Without Type 1 Diabetes-RAID-II

Overview

The goal of this trial is to study the effect that adrenaline has on the immune reaction seen during a low blood sugar. People with type 1 diabetes do not produce their own insulin. The cells in the pancreas that produce insulin are destroyed. People with type 1 diabetes require daily insulin administration. As a consequence of this insulin therapy the blood sugar can dip too low, causing symptoms such as confusion, irritation and tiredness. This is called hypoglycaemia. Hypoglycaemia has been associated with an increased risk for cardiovascular disease such as heart attacks. During hypoglycaemia the immune system is activated. The immune system consists of white blood cells which produce cytokines, these are proteins used to kill pathogens such as bacteria. During hypoglycaemia there are no pathogens but the cytokines are still produced, leading to unwanted damage. A previous study performed by our research group showed that the immune system activation caused by hypoglycaemia is associated with the stress hormone adrenaline. Adrenaline is released by the body in moments of stress such as during running or bungee jumping. Adrenaline is also released by the body during hypoglycaemia to increase the sugar level. Our hypothesis is that adrenaline activates the immune system during hypoglycaemia. Adrenaline acts in the body through two receivers, these are called alpha and beta receptors. These are present on almost all cells in the body especially on the immune cells. With the study we want to study the situation where there is a hypoglycaemia without the adrenaline. We will achieve this by lowering the blood sugar in participants. During the low blood sugar we will administer two drugs, which will attach themselves to the adrenaline receivers, the alpha and beta receptor. With this method we hope to block the adrenaline effects and with that block the immune response caused by adrenaline.

Rationale: Hypoglycaemia has shown to cause a sustained pro-inflammatory response which could promote a pro-atherogenic state and explain the association between hypoglycaemia and cardiovascular events. This pro-inflammatory response has been linked to the adrenaline response to hypoglycaemia. Adrenergic blockade with α and β adrenergic receptor antagonists (ARA) has shown to blunt the leukocyte response after hypoglycaemia induction and adrenaline administration. Whether and to what degree a combined blockade blunts the hypoglycaemia induced pro-inflammatory response is unknown. Objective: to examine the effect of adrenergic inhibition on the hypoglycaemia induced inflammatory response (e.g. leukocyte phenotype, cytokines, inflammatory proteins) by performing a hyperinsulinaemic hypoglycaemic glucose clamp alongside infusion of α-ARA and β-ARA. Secondary objectives consist of the effect of adrenergic blockade during hypoglycaemia on atherogenic parameters and glucose metrics ( e.g. time in range). Study design: Intervention study with a cross-over design Study population: Potentially eligible adult ( 16 - 75 years) participants will be recruited through social media, the Radboudumc outpatient clinic and other advertisements. We will recruit a total of 24 individuals, i.e. 12 healthy participants and 12 participants with type 1 diabetes. Participants with type 1 diabetes will be twice ( as there are two investigational days) equipped with a blinded continuous glucose monitoring device (CGM) during the test, which will measure interstitial glucose levels for a total of 10 days. Intervention: All participants will undergo a hyperinsulinaemic hypoglycaemic glucose clamp ( nadir 2.8 mmol/L). During the clamp the participants will be randomized to receive an infusion of saline or an infusion of phentolamine and propranolol. This will be done using a cross-over design. The participants will undergo both the saline and adrenergic blockade. Main study parameters/endpoints: The main study parameter will be the monocyte count after 60 minutes hyperinsulinaemic hypoglycaemic clamp and adrenergic blockade during the clamp.