Can blood pressure lowering drugs prevent the onset of type 2 diabetes?

This study evaluated the effect of angiotensin converting enzyme inhibitors (ACEIs) on the development of type 2 diabetes. 

Diabetes, or diabetes mellitus, is a group of metabolic diseases in which a person has high blood sugar mainly due to the body not producing the sugar-lowering hormone, insulin, (type 1 diabetes) or the body no longer responding to insulin (type 2 diabetes).

ACEIs are drugs that lower blood pressure (e.g. Lotensen, Capoten) but recent evidence suggests that they help reduce the progression of diabetes by increasing the body’s sensitivity to insulin.

This study evaluated the effect of ACEIs on the development of new-onset (type 2 diabetes) diabetes.

Nine clinical trials with a total of 92,404 patients (72,128 non-diabetic patients at the beginning of the study) that investigated the effect of ACEIs on the onset of type 2 diabetes were included in this study. The results show that the occurrence of new-onset type 2 diabetes was significantly reduced by 20% in the ACEI groups when compared to the group that did not receive ACEIs, especially among patients with hypertension (high blood pressure), coronary artery disease or cardiovascular disease (narrowed or blocked blood vessels) and heart failure. Other blood pressure lowering drugs such as calcium channel blockers (e.g. Norvasc, Cardizem) and diuretics (e.g. Esidrix, Lasix) did not produce the same beneficial effect. 

Among patients with impaired glucose tolerance (high levels of blood glucose), ramipril (Altace) did not significantly reduce the occurrence of diabetes, but it did significantly contribute to patients returning to normal blood glucose levels. 

ACEIs show beneficial effects in preventing the onset of type 2 diabetes, especially among patients with hypertension, coronary artery disease and cardiovascular disease. 

Most participants recruited in these trials were white and this may limit the generalization of the findings for all other ethnicities.