Sales Débora S, Moreira Ayrton C, Camacho-Hübner Cecilia, Ricco Rubens G, Daneluzzi Júlio C, Campos Antônio D, Martinelli Carlos E
Division of Endocrinology, Department of Paediatrics, School of Medicine of Ribeirão Preto-USP, Ribeirão Preto, Brazil.
J Pediatr Endocrinol Metab. 2003 Jul-Aug;16(6):827-33. doi: 10.1515/jpem.2003.16.6.827.
Premature thelarche (PT) is characterised by precocious breast development without any other sign of puberty, normal height velocity (HV) and normal bone maturation, while girls with central precocious puberty (CPP) show increased HV, bone maturation and increased serum IGF-I and IGFBP-3 levels. This prompted us to study serum IGF-I and IGFBP-3 concentrations in girls with PT. Thirty-nine girls with premature breast development were studied and classified as PT or CPP according to clinical and laboratory evaluation. Normal prepubertal and pubertal girls were studied as controls. Serum IGF-I and IGFBP-3 were determined in all girls by IRMA. IGF-I levels in PT (155 +/- 61 microg/l) were lower than in CPP (337 +/- 149 microg/l) or late-pubertal controls (355 +/- 84 microg/l) and similar to those found in prepubertal (113 +/- 72 microg/l) and early-pubertal (222 +/- 81 microg/l) girls. Considering the SDS of IGF-I for chronological age (CA), the values observed in PT were in an intermediate position between CPP and prepubertal controls and statistically similar to those observed in CPP and prepubertal girls. IGFBP-3 levels in PT (2.1 +/- 0.5 mg/l) were similar to those found in CPP (2.5 +/- 0.8 mg/l), but only the latter were higher than in prepubertal girls (1.9 +/- 0.9 mg/l). IGF-I/IGFBP-3 molar ratios in PT were in an intermediate position between CPP and prepubertal controls. In conclusion, IGF-I and IGF-I/IGFBP-3 values in PT are intermediate between those observed in prepubertal children and in CPP, suggesting that PT could be a very early stage of puberty with slight but real changes in the GH-IGF axis.
性早熟乳房发育（PT）的特征是乳房过早发育，而无任何其他青春期迹象，身高增长速度（HV）正常，骨成熟正常；而中枢性性早熟（CPP）女孩则表现为HV增加、骨成熟加快以及血清胰岛素样生长因子-I（IGF-I）和胰岛素样生长因子结合蛋白-3（IGFBP-3）水平升高。这促使我们研究PT女孩的血清IGF-I和IGFBP-3浓度。对39例乳房过早发育的女孩进行了研究，并根据临床和实验室评估分为PT或CPP。将正常青春期前和青春期女孩作为对照进行研究。通过免疫放射分析（IRMA）测定所有女孩的血清IGF-I和IGFBP-3。PT女孩的IGF-I水平（155±61μg/L）低于CPP女孩（337±149μg/L）或青春期后期对照（355±84μg/L），与青春期前（113±72μg/L）和青春期早期（222±81μg/L）女孩的水平相似。考虑到按实足年龄（CA）计算的IGF-I标准差分值（SDS），PT女孩的观察值处于CPP和青春期前对照之间的中间位置，且在统计学上与CPP和青春期前女孩的观察值相似。PT女孩的IGFBP-3水平（2.1±0.5mg/L）与CPP女孩（2.5±0.8mg/L）相似，但只有后者高于青春期前女孩（1.9±0.9mg/L）。PT女孩的IGF-I/IGFBP-3摩尔比处于CPP和青春期前对照之间的中间位置。总之，PT女孩的IGF-I和IGF-I/IGFBP-3值处于青春期前儿童和CPP之间的中间位置，提示PT可能是青春期的一个非常早期阶段，生长激素-IGF轴存在轻微但真实的变化。
