Hypertension and prognosis in established diabetic nephropathy.

In the patient with diabetes mellitus the onset of intermittent and then persistent proteinuria signals the development of established nephropathy. This heralds an extremely poor prognosis and mortality in this group has been estimated to be 80 to 100 times greater than that of an age-matched normal population. The excess mortality and its associated morbidity exists for both insulin-dependent and non-insulin-dependent patients who develop proteinuria. The final cause of death is often cardiovascular, such as myocardial infarction or a cerebrovascular accident, rather than end stage renal failure with death from uraemia. Strict and aggressive control of blood pressure during this stage is the only therapy that has been shown to slow the decline in glomerular filtration. To date, there have been no studies large enough to establish if this can produce the desired effect of reducing the excess mortality in this group. The newer antihypertensive agents may have a specific role but this also remains to be shown conclusively; their major advantage may be related to their fewer side-effects especially on cardiovascular risk factors in this highly susceptible group.