[Antihypertensive therapy in diabetes mellitus].

Approximately 150 million people worldwide have diabetes mellitus, of whom 90% are type II diabetics. It is therefore of no surprise that diabetic nephropathy has become the leading cause of end-stage renal disease. Opposite to what has been known previously, kidney disease is at least as common in type II as in type I diabetes. However, because the majority of type II diabetics has hypertension for many years before diabetes mellitus becomes clinically relevant, renal lesions are often heterogeneous with frequent exclusive presence of ischemic changes. For the treatment of hypertension in diabetics without nephropathy (no microalbuminuria), drugs that exert beneficial effects or are at least neutral with respect to lipid and glucose metabolism, such as ACE inhibitors, angiotensin II-receptor antagonists, non-dihydropyridine-calcium channel blockers and the thiazide-like indapamide, are to be preferred. Although metabolically neutral, dihydropyridine calcium channel blockers should be used with caution, since an increase in cardiovascular morbidity and mortality in type II diabetics treated with these compounds has most recently been described. Once that diabetic nephropathy is established, blood pressure should be lowered to 120/80 mmHg (measured in seated position). Antihypertensive treatment should primarily be based on ACE inhibitors; angiotensin II-receptor antagonists are a valuable alternative if ACE inhibitors are not tolerated. Both ACE inhibitors and angiotensin II-receptor antagonists should be used with high caution in elderly patients with severe atherosclerosis in whom acute renal failure could occur due to the presence of bilateral renal artery stenosis. Newer studies indicate that non-dihydropyridine calcium channel blockers such as verapamil and diltiazem may be as effective as ACE inhibitors in preserving renal function in diabetic nephropathy. A fix-dose combination of the ACE inhibitor trandolapril with verapamil is now available; it should be reserved for patients whose blood pressure and/or proteinuria can not be adequately controlled with ACE inhibitors. Finally, indapamide is the only antihypertensive diuretic with nephroprotective properties.