Blood pressure reduction as a preventive treatment of diabetic nephropathy

Arterial hypertension is present in 10-80% of newly diagnosed Type 2 diabetics, and in 30-50% of Type 1 diabetics after some years. In patients with overt nephropathy, correction of hypertension is associated with a reduction in the rate of decline of glomerular filtration rate. In most patients without clinical diabetic nephropathy, arterial pressure remains within normal limits as defined by usual criteria, whether or not microalbuminuria is present. Short-term studies of Type 1 diabetics with microalbuminuria suggest that angiotensin-converting enzyme inhibitors result in a fall in urinary albumin excretion rate more than calcium antagonists and diuretics. Additional studies assessing the long-term effect of different antihypertensive agents on the evolution of early diabetic nephropathy are needed before the superiority of any drug can be claimed. In addition, non pharmacological approaches, including optimal glycemic control as well as modification of dietary sodium and serum lipid profile, may alter the progressive course of elevation in arterial pressure and decline in renal function. The optimal level of blood pressure for diabetic patients remains to be determined.