Does blood glucose control influence heart disease?

This study looked at whether blood glucose control influenced heart disease and stroke for patients with type 2 diabetes (T2D). It found that patients with better blood glucose control had a lower risk of heart disease and stroke over the following 8 years.

T2D is a disorder in which the body does not respond well to the hormone insulin, leading to high levels of glucose (sugar) in the blood. Over time, high blood glucose can cause inflammation and damage small blood vessels.

Patients with T2D have a higher risk of high blood pressure and cardiovascular disease (CVD), including heart attack and stroke. However, it is not clear whether high glucose levels lead to this increased risk. For example, obesity can worsen both CVD and T2D, which may explain their connection to each other. It is not clear whether good glucose control can lower the risk of heart attack and stroke for patients with T2D.

This study used records from 174,028 patients with T2D. All patients were initially between 45 and 84 years old. They were followed for an average of 8.4 years. Over that time there were 34,072 cardiovascular events such as heart attack, heart failure, or stroke.

Glycated hemoglobin (HbA1c) is a measure of glucose control over the previous two-three months. For those with T2D, the target for good blood glucose control is an HbA1c below 7%. Patients were grouped according to their usual HbA1c scores.

Below the target HbA1c, there was no connection between CVD and blood glucose. Above this target, every 1% increase in HbA1c led to a 21% increase in the risk of a CVD event. Each 1% increase in HbA1c also led to a 37% increase in the risk of death due to CVD.

This study found that patients with better blood glucose control have a lower risk of heart attack, heart failure, and stroke compared to patients with uncontrolled T2D.

High blood glucose and CVD were more closely connected for middle-aged patients than for elderly patients. For middle-aged patients, improving health factors such as glucose levels can lead to greater improvement in outcomes.