Diabetes and hypertension are two main causes of end-stage renal disease (ESRD) or diabetic nephropathy, as these two disorders account for around 40% and 25% of all cases, respectively. Diabetic nephropathy treated with drugs helps in lowering blood pressure and protein content in the urine.

Angiotensin-converting enzyme (ACE) inhibitors reduce both blood pressure and proteinuria. It acts through a mechanism of action, stopping the body from creating angiotensin II hormone. The process is carried out by inhibiting angiotensin-converting enzyme (ACE) that helps in relaxing blood vessels which in turn help reduce blood pressure. The relaxation of blood vessels helps reduce re-absorption of water by the kidneys. These actions help to decrease blood pressure, relieving the pressure on the kidney, thus alleviating diabetic nephropathy. The role of ACE inhibitors in slowing diabetic neuropathy shows that captopril (ACE inhibitor) leads to a better reduction in the rate of decline in renal function, and also helped to reduce death by diabetic retinopathy by 50%.

The ability of ACE inhibitors to relax blood vessels has become one of the most important steps in decreasing renal failure. It is used in first-line therapies for the treatment of diabetic retinopathy. Side effects observed are minimal;  such as dry cough and other similar illness. Thus, ACE inhibitors are helpful in treatment of diabetic nephropathy.