Bone Maturation and Bone Mineralization in Precocious Puberty: Relation to Estrogen Receptor Gene Polymorphisms

摘要

Estrogen plays an important role in bone maturation and bone mineralization. To elucidate the physiological roles of estrogen in the regulation of bone growth, we investigated the relationship between bone mineral status and the estrogen receptor (ER) gene polymorphism in subjects with precocious puberty, where excess estrogen is exposed to the bone. Thirty-six patients with central precocious puberty or early puberty were enrolled in the study. The relationships between PvuII and XbaI restriction fragment length polymorphisms of the ER gene and the lumbar spine bone mineral density (BMD), BMD SD score adjusted for either chronological age or bone age, were evaluated. The mean BMD value for bone age (-0.52 ± 0.83 SD) was significantly lower than the BMD value for chronological age (0.30 ± 0.96 SD) (p<0.01), indicating that bone maturation (advancement of bone age) was not associated with bone age-matched mineralization (increase in BMD). Furthermore, the PP genotype for the PvuII polymorphism appeared to be associated with an increased BMD (p<0.05), suggesting that the ER gene genotype may be related to bone mineral accretion during estrogen exposure. ER gene polymorphisms might thus account for the varying degrees of increase in BMD after estrogen exposure, leading to the dissociation of bone maturation and bone mineralization.