Đang chuẩn bị liên kết để tải về tài liệu:
Abnormalities in Puberty - part 10

Không đóng trình duyệt đến khi xuất hiện nút TẢI XUỐNG Tải xuống

Hiến pháp chậm trễ của tăng trưởng và tuổi dậy thì đại diện một dấu hiệu cho thấy tiềm năng cho T điều trị [63]. Các nghiên cứu ở một số ít thanh thiếu niên tuổi dậy thì chậm cho thấy tiêm hàng tháng của T thấp có thể làm tăng mật độ xương | Management of Delayed Puberty Constitutional delay of growth and puberty represents another potential indication for T therapy 63 . Studies in a small number of adolescents with delayed puberty suggest that monthly injections of low T may increase bone density 29 64 . However the ultimate impact of this treatment on adult bone density has not been documented. It is also not clear to what extent such increase in bone density is due to an increase in bone size. According to Bertelloni et al. 32 no differences in areal and volumetric BMD of the spine were found in boys with delayed puberty either untreated or treated with T. The nonaromatizable androgen oxandrolone has been reported to increase height gain and bone maturation to the same extent as T in boys with delayed puberty 65 66 . In boys treated with oxandrolone the predicted adult height is significantly increased 66 . To date no data are available on its effect on bone density in these patients except one study in a small number of patients indicating that neither T nor oxandrolone increases areal or volumetric BMD 32 . Recently Wickman et al. 67 demonstrated that combined treatment of testosterone and an aromatase inhibitor appears to increase the predicted final height more than testosterone alone by delaying bone maturation and epiphyseal fusion. This type of treatment did not seem to impair peak bone mass acquisition 64 but the number of observations and the duration of the study were limited. In growing male rats however aromatase inhibitors impair peak bone mass acquisition and volumetric BMD 68 . Conclusions Gonadal failure or even a delay of sex steroid secretion during the period when the skeleton acquires 50 of its bone mineral is a major health problem potentially with consequences into old age. In this regard age-associated osteoporosis may in part be considered a pediatric disease. To date most studies have focused only on issues such as the development of secondary sex characteristics the .