Diabetic glomerulopathy in young IDDM patients. Preventive and diagnostic aspects

The clinical course of diabetic nephropathy may be described in stages; the normo-, micro- and macroalbuminuric stage. The basis for its development is the diabetic glomerulopathy in which accumulation of basement membrane (BM) material is pivotal. Normoalbuminuric patients have normal or slightly increased BM thickness; microalbuminuric patients show further BM thickening and mesangial expansion, formation of new capillaries, arteriolar and interstitial changes. The degree of diabetic glomerulopathy may be predicted by long-term glycemic control, diabetes duration and glomerular filtration rate (GFR). A slight decline in GFR in microalbuminuric patients is associated with increases in BM thickness, capillary diameter and interstitial volume fraction. In turn, the degree of early diabetic glomerulopathy may predict the level of microalbuminuria several years later. Improved metabolic control, even to not normal levels, retards the increase of BM thickness and matrix volume in microalbuminuric adolescents. If matrix accumulation may be prevented diabetic nephropathy will not develop. Morphometric analyses may thus be useful in evaluating the effect of intervention, also during shorter periods and at early stages.