Poster Session I: Diabetes Acute and Chronic Complications I P/001/WED The effect of age at onset type 1 diabetes on the development of diabetic nephropathy in children and adolescents with T1DM

Objective: To analyze the impact of age at onset on the development of diabetic nephropathy children and adolescents with T1DM. Methods: We studied children and adolescents in whom type 1 diabetes mellitus (T1DM) was diagnosed before the age of 15 years between 1992 and 2005 years in a Moscow district. MAY screening [albumin excretion rate (AER) in three timed overnight samples: mean AER ‡30 mg/day and £300 mg/day)] was performed yearly after 10 years of age from diagnosis. For the analysis, the patients were divided into three groups: those who were aged <5 years (n = 95), 5–10 years (n = 106) and >10 years at diagnosis (n = 62) enabled the evaluation of the effect of diabetes duration and on the development of MAY. Kaplan-Meier survival analyses (log-rank test) estimated the probability of developing MAY. Results: Two hundred and sixty-three (263) T1DM children and adolescents, mean age of 12.9 years, mean diabetes duration of 5.8 years and mean age at onset of diabetes of 6.9 years were selected for the study. Cumulative probability for MAY was 10.2% after 10 years. Among those aged <5 years at diabetes onset, the probability for MAY was 5.4% after 10 years of diabetes duration. This same probability was achieved after only 1 year among those who were diagnosed with diabetes>10 years of age. MAY remained constant over time among the oldest ageat-onset group (5–10 years, ->10 years), while in the youngest age-at-onset group (<5 years), the cumulative probability for MAY started to increase after a period of 8 years of diabetes. After 10 years of diabetes, in the group with a diagnosis before the age of 5 compared with the two other groups, cumulative probability of microalbuminuria was lower (age at diagnosis <5 years: 5.4%; 5–10 years: 28.5%; >10 years: 33%; log rank test P < 0.05). Conclusions: Children diagnosed with T1DM at younger age seem to prolong the time for developing MAY.