Prorenin and vascular complications of diabetes.

A high plasma prorenin is a marker of microvascular complications of diabetes. We have followed 56 adults and 120 children with uncomplicated insulin-dependent (type 1) diabetes. When plasma prorenin rises above the normal range in an adolescent or adult with type 1 diabetes, signs of nephropathy, retinopathy, or neuropathy follow within one to two years. The earliest sign may be intermittent microalbuminuria, which can often be abolished by improved control of hyperglycemia. The association between increased plasma prorenin and complications of noninsulin-dependent (type 2) diabetes is less reliable in patients with hypertension and in those receiving medication that affects plasma prorenin. The oral hypoglycemic agent, glipizide, lowers plasma prorenin, but its effect on prognosis is unknown. Plasma prorenin and renin decline as blood pressure rises, whereas the prevalence of micro- and macroalbuminuria increases. Many drugs used to control hypertension affect the level of prorenin. In the majority of our patients with type 2 diabetes who are hypertensive or are taking a medication that affects plasma prorenin, microalbuminuria may prove to be a more reliable warning of vascular complications.