[The metabolic control of insulin-dependent diabetes mellitus and diabetic nephropathy]

Long-term complications of Insulin Dependent Diabetes Mellitus (IDDM) have been associated with several risk factors, particularly the degree of metabolic control and evolution time of the disease. A study was conducted with 219 randomly selected patients with IDDM at our clinic; evolutive, clinical and analytical parameters were assessed and conventional or multiple insulin therapy was evaluated. The classification of glycated hemoglobin (Hb A1c) in quartiles demonstrated a relatively higher incidence of diabetic retinopathy and nephropathy in the upper quartiles versus the lower quartile (p < 0.05). Likewise, patients with multiple insulin therapy had lower retinopathy (24.5% vs. 50.6, p < 0.001) and nephropathy rates (12.9% vs. 26.6%, p < 0.05) compared with those following a conventional insulin therapy. The multivariate analysis showed a statistically significant regression model (p < 0.001) for microalbuminuria level in patients with no established nephropathy; in these patients, the evolution time of IDDM and their Hb A1c level showed a positive independent association, and the use of multiple insulin therapy was a protective factor. The regression analysis of microalbuminuria levels compared with glycated hemoglobin in patients with no established nephropathy showed a value for Hb A1c of 9% as a break-point; from this point upwards microalbuminuria levels increased more markedly. The multivariate analysis here presented can help identify the presence of microalbuminuria in the pathological range in patients with IDDM followed at a hospital clinic from feasible clinical variables (evolution time, glycated hemoglobin level, program of insulin therapy used) establishing a metabolic objective which helps prevent the development of this complication.