Incidence and Risk Factors Involved in the Development of Nephropathy in Patients with Type 1 Diabetes Mellitus: Follow Up Since Onset.

Abstract

Estimation of the incidence of nephropathy as well as potential risk factors involved in its onset in a cohort of patients with type 1 diabetes who were followed from diagnosis. We studied 716 patients, who were followed for a mean (standard deviation [SD]) of 10.1 (SD: 5.3) years. We analyzed the influence of demographic characteristics and levels of glycated hemoglobin (A1C), lipids and blood pressure during the course of the disease by univariate and multivariate survival methods. The cumulative incidence of nephropathy was 2.6%, 6.3% and 11.9% at 5, 10 and 15 years of evolution, respectively. The factors associated with increased risk for nephropathy were systolic blood pressure and A1C levels. An increment of 10 mm Hg in systolic blood pressure increases the risk by 36%, and an increment of 1% in A1C levels raises the risk by 13% at 5 years since onset and 68% at 10 years, and it doubles the risk at 15 years. Women have higher risk than men (hazard ratio 1.79; p=0.024). Our study suggests that female gender and high levels of A1C and systolic blood pressure throughout the course of the disease are the main factors associated with an increased risk for development of nephropathy in patients with type 1 diabetes mellitus.