Bone mineralization in Turner syndrome: a transverse study of the determinant factors in 58 patients

Turner syndrome (TS) is characterized by the presence of an X chromosome and total or partial loss of the second sex chromosome, short stature, hypergonadotrophic hypogonadism, and a variable dysmorphic picture. Delayed puberty and estrogen deficiency are some of the determinant factors of osteoporosis in TS, but the whether or not there is an intrinsic bone defect is still obscure. The aim of this study was to evaluate the correlation of the z score of bone mineral density (BMD) with age, weight, height, karyotype, associated diseases, bone age, and estrogen therapy in TS patients. We performed a transverse study with area BMD of L2-L4 with dual-energy X-ray absorptiometry (DEXA) in 58 patients with a cytogenetic diagnosis of TS, whose ages ranged from 5 to 29 years. It was observed that 86% of the patients presented with a BMD z score below -1 SD, and 46.5% with a value below -2.5 SD. There was a significant negative association of BMD with age and height, and a positive association with weight and bone mass index (BMI) z scores. A higher BMD was observed in patients with spontaneous puberty and in those with more than 2 years of hormone replacement. In conclusion, there was a high incidence of reduced bone mass among our patients, which was influenced by weight and BMI, by the use and the time of estrogen replacement, and by the presence of spontaneous puberty.