Treating hypertension and microalbuminuria is one of the most importan
t tasks next to blood glucose control in the treatment of adolescents
with diabetes mellitus type 1. Normoglycemia as well as normotensive b
lood pressure values are able to prevent cardiac, vascular and renal c
omplications of diabetes. The prevalence of arterial hypertension in p
atients with diabetes is considerably higher compared to the general p
opulation. The development of diabetic nephropathy is strongly associa
ted with arterial hypertension. Diabetic nephropathy can be regarded e
ither as cause or result of hypertension. Microalbuminuria, which can
be observed already in childhood and adolescence, is the earliest indi
cator of progressive renal destruction. One of the most serious compli
cations of juvenile diabetes still is terminal renal failure. Recent s
tudies demonstrate that familial and genetic factors play an important
role in the pathogenesis of diabetic nephropathy. Early identificatio
n of patients at risk is warranted. Regular measurement of arterial bl
ood pressure and routine urine analysis for albuminuria is a prerequis
ite of the care of children and adolescents with diabetes. Early inter
vention, especially treatment with ACE inhibitors will improve the pro
gnosis for diabetic nephropathy in adolescents with elevated blood pre
ssure and/or microalbuminuria.