Metabolic characteristics and urine albumin excretion rate in relation to pubertal maturation in Type 1 diabetes

Background The objective of this study was to assess the impact of pubertal maturation on urinary albumin excretion rate (AER) and persistent microalb uminuria, and to identify possible factors affecting urinary AER in adolesc ents with Type 1 diabetes. Methods One hundred patients aged 9.1-19.0 years with a duration of diabete s of >2 years out of 138 eligible adolescents with Type 1 diabetes from an outpatient diabetes clinic participated in the study, together with 100 hea lthy controls. A timed overnight urine sample was collected in the hospital , where all the adolescents stayed for 22-24 h, and microalbuminuria was co nfirmed with at least one consecutive positive sample (AER 20-200 mu g/min) . Results The prevalence of persistent microalbuminuria was 6%. All the patie nts affected were girls: one prepubertal (T I), one in late puberty (T IV) and three postpubertal (T V). These patients had significantly higher HbA(1 c) levels than did the normoalbuminuric girls with Type 1 diabetes. Neither duration of diabetes nor age differed significantly between the two groups . AER increased more conspicuously with pubertal maturation in the boys wit h Type 1 diabetes than in the control boys, while the girls with diabetes h ad significantly higher body mass index (BMI) and serum total and LDL chole sterol than did the control girls. HbA(1c) was independently associated wit h AER in a multiple regression model. Diastolic blood pressure (BP) was ele vated in both girls and boys with Type 1 diabetes as compared with healthy adolescents, while no difference was observed between the patients with mic roalbuminuria and normoalbuminuria. Conclusions Persistent microalbuminuria was mainly observed in late puberty and after puberty among adolescents with Type 1 diabetes. Female sex and p oor metabolic control predispose such adolescents to this condition during pubertal maturation. Copyright (C) 2000 John Wiley & Sons, Ltd.