The development, enhancement, and reversal of the secondary complications of diabetes mellitus.

Diabetic glomerulopathy continues as a major problem in the management of the patient with diabetes mellitus; however, evidence in man and in animals underlines the fact that good control of diabetes favorably alters the course of this complication. Islet transplantation in the diabetic rat returns plasma glucose and insulin levels to normal. In parallel mesangial matrix thickening, mesangial deposition of immunoglobulin and urinary excretion of albumin markedly improve following islet transplantation. Although amelioration of diabetes affects the course of glomerulopathy, other factors (most notably measures that increase glomerular capillary pressure) enhance the development of the diabetic renal lesions. Following uninephrectomy or clipping of a renal artery, the remaining (in the case of uninephrectomy) or unclipped diabetic kidney develops the morphologic and functional changes of diabetic nephropathy at a rate greater than in kidneys in an intact diabetic rat. The clipped kidney demonstrates diminished diabetic changes, suggesting a protective effect with decreased glomerular capillary pressures. In addition to measures improving the control of diabetes, procedures reducing factors accelerating diabetic complications may improve the prognosis in diabetic glomerulopathy.