Prepubertal urinary estrogen excretion and its relationship with pubertal timing.

摘要

Whether prepubertal estrogen production impacts on the timing of puberty is notclear. We aimed to investigate prepubertal 24-h estrogen excretion levels andtheir association with early and late pubertal markers. Daily urinary excretionrates of estrogens of 132 healthy children, who provided 24-h urine samples 1 and2 yr before the start of the pubertal growth spurt [age at takeoff (ATO)], werequantified by stable isotope dilution/GC-MS. E-sum3 (estrone + estradiol +estriol) was used as a marker for potentially bioactive estrogen metabolites and E-sum5 (E-sum3 + 16-epiestriol + 16-ketoestradiol) for total estrogen production.Pubertal outcomes were ATO, age at peak height velocity (APHV), duration ofpubertal growth acceleration (APHV-ATO), age at Tanner stage 2 for pubic hair(PH2), genital (G2, boys) and breast (B2, girls) development, and age atmenarche. Prepubertal urinary estrogen excretions (E-sum3 and E-sum5) were notassociated with ATO, APHV, and age at PH2 but with duration of pubertal growthacceleration (P < 0.01) in both sexes. Girls with higher E-sum3 reached B2 0.9 yr(P = 0.04) and menarche 0.3 yr earlier (P = 0.04) than girls with lower E-sum3.E-sum3 was not associated with age at G2 in boys (P = 0.6). For most pubertalvariables, the associations with E-sum3 were stronger than with E-sum5. Inconclusion, prepubertal estrogens may not be critical for the onset of thepubertal growth spurt but are correlated with its duration in both boys andgirls. Prepubertal estrogen levels may already predict the timing of girls'menstruation and breast development but do not appear to affect sexual maturationin boys.