Avaliação de fatores determinantes da densidade mineral ossea areal na sindrome de Turner : estudo transversal de 58 casos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

Turner syndrome (TS) is an abnormality of the X ehromosome, characterized mainly by endogenous estrogen deficieney and short stature. Most bone density studies in patiens with TS have presented osteoporosis as a consequence of the absence of pubertal development and low estrogen levels. However, intrinsie factors of bone changes related to TS have not been completely clarified yet. The aim of this study was to evaluate the variables that can modify the bone mineral density (BMD). Thus, 58 subjects with cytogenetic diagnosis of TS, aged 5 to 29 years , followed up in the Pediatric and General Endocrinology Units of the School Hospital at the State University of Campinas have been studied. Abone densitometry using the Dual Energy X-ray Absorptiometry (DEXA) technique was performed. The values of the L2-L4 areal BMD z score were evaluated in relation to chronological and bone age, height, weight, associated diseases (nephropathy, cardiopathy and hypothyroidism), karyotype, pubertal development, age at the beginning of the estrogen therapy, duration and dose of estrogen therapy. Statistical analysis included fischer and Kruskal - Wallis tests with significance when p was <0.05. It has been observed that older patients presented lower BMD z secres (non pubertal patients). Besides, taller non pubertal patients presented lower BMD z scores, probably due to their ages. Lower BMD z scores of weight and body mass index (BMI) were found among patients with lower BMD z scores. Higher BMD z scores were observed in patients with spontaneous puberty, and lower values in patients who had undergone estrogen therapy. It was necessary over 2 years of estrogen therapy in order to observe higher BMD z secres. According to the karyotype, after the beginning of puberty, the 45,X/46,XX mosaicism was related to higher BMD z scores, while non pubertal patients, were related to lower BMD z scores. Bone age, age at the beginning of estrogen therapy, estrogen dose, height z score (in relation to normal and TS population data), weight, BMI, presence of Y chromosome and associated diseases have not presented statisticaly significant correlation with BMD z scores. It was observed that 86% ofthe patients presented BMD z score below -1 SD, and 46.5% below -2,5 SD. Therefore, TS patients showed low values of L2-L4 areal BMD, probably due to weight and BMI z scores, the karyotype, the use and time of estrogen replacement beginning and the presence of spontaneous puberty.

ASSUNTO(S)

densitometria estrogenos turner osteoporose sindrome de

ACESSO AO ARTIGO

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