The kidney in diabetes: How to control renal and related cardiovascular complications

Abstract

The clear-cut and detailed pathogenesis of diabetic renal disease is not yet elucidated, but it is clear that both initiation and progression of renal disease in diabetes is related to glycemic control and blood pressure (BP) regulation, also seen in intervention studies. Consequently, optimal control of glycemia and antihypertensive treatment have become the cornerstones in the management of patients with diabetes. Naturally, modulating factors need to be discussed in further detail. The genetics of diabetes and its renal complications are still very complex issues that need to be explored further. Few and inconclusive data are available with respect to clinical management, for which genotyping is not required. Dietary protein content has long been an interesting avenue for possible treatment, but to date, data from patients with nondiabetic renal disease and with diabetes are not totally convincing, although further results may be published very soon. The issue is also complex because a low-protein diet may increase BP according to new studies, rendering the issue of low-protein content in the diet still more complex and controversial. Metabolic issues remain a key question, specifically with regard to glycemic control, in which data have accumulated over the past decade from epidemiological and interventional studies. There is no doubt that optimal glycemic control is crucial, but issues regarding specific glucose-related mechanisms and protein and lipid metabolism are still under investigation. The renin-angiotensin system has emerged as a key issue in diabetes, especially with regard to its inhibition by angiotensin-converting enzyme (ACE) inhibition and angiotensin-receptor blockade. New studies suggest that more complete inhibition of this system by dual blockade may be an avenue for further study according to positive results in patients with microalbuminuric type 2 diabetes, who are at great risk. Antihypertensive treatment still remains a fundamental component, although the metabolic effects of some antihypertensive agents may be important, especially with respect to diuretics, β-blockers, and possibly α-blockers. The situation becomes complex with the frequent combination of various agents in the treatment of hypertension in patients with diabetes. Conversely, ACE inhibitors may have some diabetes-protective effect, but further studies are needed.