Enhanced progression of urinary albumin excretion in IDDM during puberty

OBJECTIVE - To determine whether the progression of urinary albumin excretion rate (AER) is higher during puberty than before or after this period. RESEARCH DESIGN AND METHODS-A prospective study was conducted in which normoalbuminuric prepubertal (n = 20), pubertal (n = 28), and postpubertal (n = 26) IDDM groups matched for diabetes duration and long-term metabolic control were followed for 3 years. At 6-month intervals, 24-h urine collection was used to determine AER. RESULTS - AER increased significantly over a period of 3 years in the pubertal (P = 0.001) and postpubertal (P = 0.003) subjects but not in prepubertal subjects. The annual progression of AER was significantly higher in the pubertal group than in the prepubertal (P = 0.001) or postpubertal (P = 0.001) groups. Six pubertal, two postpubertal, and none of the prepubertal subjects developed microalbuminuria (AER greater than or equal to 20 mu g/min on two consecutive occasions) over a 3-year period (P = 0.047). Multiple logistic regression analysis showed that the risk of development of microalbuminuria was increased in pubertal subjects compared with the prepubertal and postpubertal subjects (adjusted relative risk [95% CI]: 4.3 [1.5-9.3], P = 0.012, and 2.1 [1.1-5.0], P=0.023, respectively). CONCLUSIONS - Puberty represents an independent risk of the development of microalbuminuria in diabetes. This finding suggests that the endocrine changes of puberty lead to an accelerated process of early kidney damage in diabetes. In pediatric diabetes care, screening for microalbuminuria is needed soon after the onset of puberty.