Intensive versus conventional glycemic control in type 2 diabetes mellitus patients: the effects on diabetes complications

The present review compared the effects on diabetes complications of an intensive glycemic control (IGC) versus a conventional glycemic control (CGC) in patients with type 2 diabetes mellitus (T2DM).

T2DM is the most common form of diabetes. T2DM appears either because the pancreas does not produce enough insulin or because the body cannot use insulin properly (a process called insulin resistance). Insulin is needed so the cells can use glucose as energy. When insulin resistance occurs, glucose cannot enter the cells and builds up in the blood (leading to high blood sugar – hyperglycemia). This leads to diabetes complications such as eye (known as retinopathy), kidney (or nephropathy), nerve (or neuropathy) and heart (cardiovascular) complications. Patients with T2DM are more likely to suffer from heart attacks. The goal in T2DM treatment is not only to reach glycemic (blood sugar) control, but to reduce the risk of complications.

Previous studies have shown that complications can be prevented by keeping glucose levels as low as possible. The authors identified 14 clinical trials (in the medical literature) that compared the effects on diabetes complications of an intensive versus a conventional glycemic control. Overall, 28614 patients with T2DM were included. 15269 patients were randomly assigned to the IGC group and 13345 patients to the CGC group. 

There was no significant difference regarding the risk of death between the two groups. However, there was a 15% lower risk of heart attack in patients in the IGC group compared to patients in the CGC group. Also, patients in the IGC group had a 20% lower risk of developing eye problems and a 17% reduction in the risk of kidney complications compared to patients in the CGC group. Still, patients in the IGC group had a 30% increased risk of developing severe hypoglycemia (low blood sugar).

In summary, according to this review, an intensive glycemic control does not seem to change the risk of death compared to a conventional glycemic control. IGC might lower the risk of heart attack, eye or kidney complications, however it may also increase the risk of severe hypoglycemia.

This review included various trials, with different definitions of what represents an intensive glycemic control. Also, patients received a wide range of diabetes treatments in order to achieve glycemic control.