Reducing LDL cholesterol may prevent heart disease in patient with type 2 diabetes

This study aimed to see if using statins to lower LDL (low-density lipoprotein) cholesterol in patients with type 2 diabetes (T2D) with high cholesterol and eye damage reduced the risk for cardiovascular (CV) events such as heart attacks, strokes, kidney disease, and deaths. The main finding of the study was that lowering LDL cholesterol reduced the number of CV events and death due to CV events.

Patients with T2D have a higher risk of heart disease. Patients with high cholesterol also have a higher risk of heart disease. Therefore, patients with both T2D and high cholesterol have an even higher risk of heart disease. Heart disease can lead to CV events. Another complication of T2D is diabetic retinopathy. This is an eye disease that can lead to blindness.

There are two main types of cholesterol: HDL (high-density lipoprotein) and LDL. HDL is known as “good cholesterol”. It removes cholesterol that has been deposited around the body. LDL is known as “bad cholesterol”. It deposits cholesterol in blood vessels. Therefore, lowering LDL stops cholesterol from building up in blood vessels. Target LDL level is below 70 mg/dL. Statins are LDL lowering drugs.

It is not known if treating patients with T2D who have high cholesterol and retinopathy with statins can decrease the rate of CV events.

This study included 1909 patients with T2D who also have high cholesterol and retinopathy. Patients were randomly assigned to either receive standard statin therapy or intensive statin therapy. Standard statin therapy meant target LDL levels between 100-120 mg/dL. Intensive statin therapy was LDL levels of less than 70 mg/dL. Patients were treated for 5 years.

After 6 months, target LDL levels were achieved in those treated with intense statin therapy (66.5 mg/dL from 93.7mg/dL at the start). LDL levels actually increased in those who received standard statin therapy for 6 months (109.6 mg/dL from 107.9 mg/dL at the start). The group treated intensely with statins were 52% less likely to have a CV event after 12 months of treatment than those treated with standard statin therapy.

There were no differences in serious side effects between the standard and the intensive treatment groups. 

The authors concluded that reducing LDL levels to below 70 mg/dL may reduce CV events in patients with T2D with high cholesterol and diabetic retinopathy.

This study was funded by Shionogi & Co., a developer of statins.

This study only included patients in Japan. Therefore, the results may not apply to all populations.