DECREASE OF GLOMERULAR HYPERFILTRATION IN SHORT-TERM DIABETIC ADOLESCENTS WITHOUT MICROALBUMINURIA

OBJECTIVE - This study has been designed to follow prospectively the GFR and UAE of young patients with short-term IDDM and normal UAE. RESEARCH DESIGN AND METHODS - The study population consisted of 19 patients with glomerular hyperfiltration and 19 patients with normal GFR, matched for duration of diabetes and age. GFR has been assessed by radiosotopic tracer and UAE by RIA at the beginning of the study and after 30.5 +/- 10.4 mo of follow-up. RESULTS - GFR decreased in the two groups but DELTA GFR of patients with glomerular hyperfiltration was greater than DELTA GFR of patients with normal GFR (0.83 +/- 0.55 vs. 0.28 +/- 0.63 ml . min-1 . mo-1; P < 0.01). UAE, BP, and prevalence of microalbuminuria were comparable between the two groups at follow-up. Rate of fall of GFR was positively correlated with initial GFR (r = 0.59, P < 0.001) but not with initial UAE, BP, or changes in HbA1c, UAE, BP, or pubertal development during follow-up. CONCLUSIONS- investigation of kidney function in children and adolescents with IDDM over a 3-yr follow-up period shows that glomerular hyperfiltration is characterized by a greater decline in GFR without an increased rate of appearance of microalbuminuria, than in patients with normal GFR.