Prevalência de Osteoporose numa amostra de mulheres Portuguesas

A osteoporose é uma doença crónica e progressiva. O diagnóstico baseia-se na avaliação de densidade mineral óssea (DMO), por absorciometria bifotónica por RX (DXA) e no conceito operacional da Organização Mundial de Saúde (OMS) indicando que a doença acontece para valores de DMO inferiores a 2,5 desvios-padrão do valor médio máximo para mulheres jovens, saudáveis de etnia caucasóide. Existe variabilidade nos valores de pico de massa óssea entre diferentes populações. Este estudo pretende avaliar a prevalência de osteoporose quando utilizada a base de referência do equipamento e quando utilizada a base de dados para score-T construída a partir da amostra.Osteoporosis is a chronic and progressive disease. Its diagnosis is based on the assessment of bone mineral density (BMD) by dual energy X-ray absortiometry (EDXA) and the operational concept of the World Health Organization (WHO) indicating that the disease happens to BMD values less than 2.5 deviations standard of the average maximum for young, healthy Caucasian women. Variability exists in what relates values of peak bone mass between different populations. The purpose of this study is to evaluate and compare osteoporosis prevalence using the equipment reference database against using our sample´s calculated T-scores

Endocrine parameters in association with bone mineral accrual in young female vocational ballet dancers

Purpose Little is known on bone mass development in dancers involved in vocational training. The aim of the present study was to model bone mineral content (BMC) accruals and to determine whether circulating levels of oestrogens, growth hormone (GH) and insulin-like growth factor I (IGF-1) explain differences in bone mass gains between vocational dance students and matched-controls. Methods The total of 67 vocational female dancers (VFD) and 68 aged-matched controls (12.1±1.9yrs and 12.7±2.0yrs at baseline, respectively) were followed for two consecutive years (34 VFD and 31 controls remained in the study for the full duration). BMC was evaluated annually at impact [femoral neck (FN); lumbar spine (LS)], and non-impact sites (forearm) using DXA. Anthropometry, age at menarche (questionnaire) and hormone serum concentrations (immunoradiometric assays) were also assessed for the same period. Results VFD demonstrated consistently reduced body weight (p0.05). However, body weight did explain the differences between groups in terms of BMC gains at the forearm (non-impact site). Conclusion Two consecutive years of vocational dance training revealed that young female dancers demonstrate consistently lower bone mass compared to controls at both impact and non-impact sites. The studied endocrine parameters do not seem to explain group differences in terms of bone mass gains at impact sites

Bone mineral density in vocational and professional ballet dancers

Summary: According to existing literature, bone health in ballet dancers is controversial. We have verified that, compared to controls, young female and male vocational ballet dancers have lower bone mineral density (BMD) at both impact and non-impact sites, whereas female professional ballet dancers have lower BMD only at non-impact sites. Introduction: The aims of this study were to (a) assess bone mineral density (BMD) in vocational (VBD) and professional (PBD) ballet dancers and (b) investigate its association with body mass (BM), fat mass (FM), lean mass (LM), maturation and menarche. Methods: The total of 152 VBD (13 ± 2.3 years; 112 girls, 40 boys) and 96 controls (14 ± 2.1 years; 56 girls, 40 boys) and 184 PBD (28 ± 8.5 years; 129 females, 55 males) and 160 controls (27 ± 9.5 years; 110 female, 50 males) were assessed at the lumbar spine (LS), femoral neck (FN), forearm and total body by dual-energy X-ray absorptiometry. Maturation and menarche were assessed via questionnaires. Results: VBD revealed lower unadjusted BMD at all anatomical sites compared to controls (p < 0.001); following adjustments for Tanner stage and gynaecological age, female VBD showed similar BMD values at impact sites. However, no factors were found to explain the lower adjusted BMD values in VBD (female and male) at the forearm (non-impact site), nor for the lower adjusted BMD values in male VBD at the FN. Compared to controls, female PBD showed higher unadjusted and adjusted BMD for potential associated factors at the FN (impact site) (p < 0.001) and lower adjusted at the forearm (p < 0.001). Male PBD did not reveal lower BMD than controls at any site. Conclusions: both females and males VBD have lower BMD at impact and non-impact sites compared to control, whereas this is only the case at non-impact site in female PBD. Maturation seems to explain the lower BMD at impact sites in female VBD

Genetic variation in Wnt/β-catenin and ER signalling pathways in female and male elite dancers and its associations with low bone mineral density: a cross-section and longitudinal study.

The association of genetic polymorphisms with low bone mineral density in elite athletes have not been considered previously. The present study found that bone mass phenotypes in elite and pre-elite dancers are related to genetic variants at the Wnt/β-catenin and ER pathways. Some athletes (e.g. gymnasts, dancers, swimmers) are at increased risk for low bone mineral density (BMD) which, if untreated, can lead to osteoporosis. To investigate the association of genetic polymorphisms in the oestrogen receptor (ER) and the Wnt/β-catenin signalling pathways with low BMD in elite and pre-elite dancers (impact sport athletes). The study included three phases: (1) 151 elite and pre-elite dancers were screened for the presence of low BMD and traditional osteoporosis risk factors (low body weight, menstrual disturbances, low energy availability); (2) a genetic association study was conducted in 151 elite and pre-elite dancers and age- and sex- controls; (3) serum sclerostin was measured in 101 pre-elite dancers and age- and sex-matched controls within a 3-year period. Eighty dancers revealed low BMD: 56.3% had at least one traditional osteoporosis risk factor, whereas 28.6% did not display any risk factor (37.2% revealed traditional osteoporosis risk factors, but had normal BMD). Body weight, menstrual disturbances and energy availability did not fully predict bone mass acquisition. Instead, genetic polymorphisms in the ER and Wnt/β-catenin pathways were found to be risk factors for low BMD in elite dancers. Sclerostin was significantly increased in dancers compared to controls during the 3-year follow-up (p < 0.05)

Associations between nutrition, energy expenditure and energy availability with bone mass acquisition in dance students: A 3-year longitudinal study

This is an accepted manuscript of an article published by Springer in Archives of Osteoporosis on 24/09/2021. Available online: https://doi.org/10.1007/s11657-021-01005-5 The accepted version of the publication may differ from the final published version.Purpose To determine whether risk factors normally associated with low bone mass in athletic populations (i.e. nutrition intake, energy expenditure and energy availability) are significant predictors of bone mass changes in vocational dance students. Methods The total of 101 vocational dancers (63 females, 12.8±2.2yrs; 38 males, 12.7±2.2yrs) and 118 age-matched controls (50 females, 13.0±2.1yrs; 68 males, 13.0±1.8yrs) were monitored for three consecutive years. Bone mass parameters were measured annually at impact sites (femoral neck – FN; lumber spine – LS) and non-impact site (forearm) using DXA. Nutrition (3-day record), energy expenditure (accelerometer), energy availability and IGF-1 serum concentration (immunoradiometric assays) were also assessed. Results Female and male vocational dancers had consistently reduced bone mass at all anatomical sites (p<0.001) than controls. IGF-1 did not differ between male vocational dancers and controls, but female dancers showed it higher than controls. At baseline, calcium intake was significantly greater in female vocational dancers than controls (p<0.05). Male vocational dancers’ fat and carbohydrate intakes were significantly lower than matched controls (p<0.001 and p<0.05, respectively). Energy availability of both female and male vocational dancers was within the normal range. A significant group effect was found at the FN regarding energy intake (p<0.05) in female dancers. No significant predictors were found to explain bone mass differences in males. Conclusion Our 3-years study revealed that both female and male vocational dancers displayed lower bone mass compared to controls, at both impact and non-impact sites. The aetiology of these findings may be grounded on factors different than those usually considered in athletic populations.The study was supported by the Portuguese Foundation for Science and Technology for supporting this research (PhD Grant: SFRH/BD/88585/2012)