Management of renal disease and hypertension in insulin-dependent diabetes, with an emphasis on early nephropathy.

In the follow-up of insulin-dependent diabetes mellitus patients with renal disease, a decline in glomerular filtration rate measured by an exact technique is the major primary end point in evaluating the progress of the disease. Abnormal albuminuria is considered an intermediate or secondary end point. All studies suggest that an increase in albuminuria indicates a decline or a risk of future decline in glomerular filtration rate. The main risk factor for progression appears to be the elevated blood pressure (which in itself may be a pathogenetic factor) that is associated with abnormal albumiuria from the microalbuminuric level. Abnormal albuminuria seems to always be associated with the risk of progression, and a reversal of abnormal albuminuria suggests a beneficial prognosis. Abnormal albuminuria is easily monitored by immunochemical procedures, including semiquantitative dipstick tests that may be important in renal screening procedures. Elevated blood pressure is important for the progression of abnormal albuminuria, but poor metabolic control seems to be the major initiating factor (although the mechanisms at a molecular biologic level are less clear). New studies confirm the strong predictive value of microalbuminuria for overt renal disease. At the same time, it is clear that microalbuminuria is associated with many cardiovascular abnormalities that cluster in some patients and is clearly associated with a poor prognosis. An intervention strategy is to achieve the best possible metabolic control without creating hypoglycemic problems or too difficult a lifestyle. Increasingly, studies underscore the value of early antihypertensive therapy, especially with angiotensin-converting enzyme inhibitors, in patients with microalbuminuria. This scenario of earlier and earlier antihypertensive treatment for microalbuminuric patients is evolving. Numerous studies indicate that microalbuminuria is stabilized or reversed by this treatment, and some new evidence suggests better preservation of glomerular filtration rate by this intervention program. Accumulating results also suggest considerable improvement in survival rate with this program in proteinuric insulin-dependent diabetes mellitus patients.