HYPO-HEART

Hypoglycaemia and cardiac arrhythmias in type 2 diabetes.

The prevalence of type 2 diabetes is increasing worldwide. The majority of patients with type 2 diabetes die prematurely or become disabled as a consequence of cardiovascular complications. Prospective studies have shown direct associations with the degree of hyperglycaemia and risk of major cardiovascular events. However, treating hyperglycaemia is a major challenge because the closer the patients get to glycaemic goals, the higher is the risk of hypoglycaemia. Large-scale diabetes outcome trials have shown conflicting results regarding the impact of intensive glucose-lowering therapy on mortality and cardiovascular risk. Some of these studies have demonstrated that intensification of glycaemic control is associated with increased cardiovascular events, but it is not clear whether these events are directly related to hypoglycaemic episodes or plasma glucose variability.

We aim to determine the prevalence of clinically relevant arrhythmias in patients with type 2 diabetes and delineate whether they are associated with episodes of hypoglycaemia or plasma glucose variability. This will be achieved by using clamp techniques, data obtained from continuous glucose monitoring and cardiac monitoring using a loop recorder. By using hyperglycaemic and hypoglycaemic clamps along with intensive monitoring of the heart in patients with type 2 diabetes compared to normal glucose tolerant (NGT) and healthy individuals, we aim to elucidate the glucose-dependency of heart rhythm and haemodynamic changes (measured by echocardiography) in the two groups.

The expected results will enhance our understanding of the relationship between level of glycaemic control and cardiovascular risk and hopefully help to develop improved strategies for the management of patients with type 2 diabetes.

Aim

We aim to test our hypothesis by investigating patients with type 2 diabetes and one or more complications to diabetes. The study consists of two parts. In Part 1, we aim to investigate changes in heart rhythm, hemodynamic regulation, and hormonal response during high fluctuations in plasma glucose and hypoglycaemia using a combined hyper- and hypoglycaemic clamp in patients with insulin-treated type 2 diabetes compared to matched NGT individuals.

In Part 2, we aim to investigate the prevalence of hypoglycaemia and fluctuations in plasma glucose in relation to the cardiac arrhythmias in patients with type 2 diabetes using continuous glucose monitoring in combination with implantable loop-recorders.



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