The effects of ovariectomy on bone mineral density, geometrical, and biomechanical characteristics in the rabbit femur

2010 ◽  
Vol 23 (01) ◽  
pp. 31-36 ◽  
Author(s):  
M. E. Kara ◽  
F. Sevil
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Animal Studies ◽  
Biomechanical Properties ◽  
Mineral Density ◽  
Cross Sectional ◽  
Tomographic Images ◽  
Three Point Bending ◽  
Rabbit Femur

SummaryThe aim of the study was to evaluate the bone mineral density, as well as the biomechanic and morphometric changes in the femur of ovariectomised rabbits.Twenty-four six-month-old New Zealand rabbits were randomly divided into an ovariectomy (n = 12) and a sham (n = 12) group. Six rabbits in each group were euthanatized at eight and 16 weeks after surgery, and the femora were resected. The morphometric data were obtained from tomographic images. Periosteal and endosteal diameters and cortical thickness were measured. Total cross-sectional, cortical and medullary areas were also measured. The bone mineral content, the bone area and the bone mineral density were measured from the proximal, distal and mid-shaft of the femur as well as the total femur by dual energy X-ray absorptiometry. Employing the three-point bending method, the ultimate force, stiffness and work-to-failure were measured. The mechanical data were normalised to obtain intrinsic biomechanical properties such as ultimate stress, elastic modulus, and toughness, all of which are independent of size and shape.The results indicated that the femur was both larger and weaker 16 weeks after surgery in the ovariectomised group. Results also suggest that the rabbit might be a useful animal model for investigation of diseases related to oestrogen loss such as human postmenopausal osteoporosis. However, additional studies with advanced techniques at several time points via in vivo animal studies, and precision and predictability analyses should be designed to standardise the rabbit as a model for osteoporosis.

Association between reproductive factors and postmenopausal osteoporosis

2011 ◽  
Vol 20 (03) ◽  
pp. 248-251
Author(s):  
H. R. Meybodi ◽  
N. Khalili ◽  
P. Khashayar ◽  
R. Heshmat ◽  
A. Hossein-nezhad ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Reproductive Factors ◽  
Population Based ◽  
Age At Menarche ◽  
Mineral Density ◽  
Cross Sectional ◽  
Number Of Children ◽  
Menstrual History ◽  
Duration Of Breastfeeding

SummaryThe present cross-sectional research was designed to study possible correlations between clinical reproductive factors and bone mineral density (BMD) values.Using the data gathered by the population-based Iranian Multicenter Osteoporosis Study (IMOS), we investigated the correlation found between reproductive factors and osteoporosis. Subjects were recruited from five major cities of Iran. Bone mineral density was measured using Dual-Energy X-ray Absorptiometry and the results were analyzed against the age at menarche and at menopause, number of pregnancies, children and abortions, and the history (and duration) of breastfeeding.Data was available for 2528 women. Gravidity and number of children were reversely correlated with BMD. Younger age at menarche was associated with higher BMD values, whereas there was no significant correlation between age at menopause and menstrual history and BMD.Our study suggests that clinical reproductive factors, particularly number of children and breastfeeding, could be incorporated as predictors of BMD levels in women. Given the controversial results obtained in different studies, longitudinal studies should be carried out to enlighten the importance of these factors and the rationale of their use to predict BMD values in different settings.

scholarly journals Somatic maturation and the relationship between bone mineral variables and types of sports among adolescents: cross-sectional study

2017 ◽  
Vol 135 (3) ◽  
pp. 253-259 ◽  
Author(s):  
Ricardo Ribeiro Agostinete ◽  
Igor Hideki Ito ◽  
Han Kemper ◽  
Carlos Marcelo Pastre ◽  
Mário Antônio Rodrigues-Júnior ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Peak Height ◽  
Cross Sectional Study ◽  
Height Velocity ◽  
Whole Body ◽  
Sectional Study ◽  
Peak Height Velocity ◽  
Mineral Density ◽  
Cross Sectional

ABSTRACT CONTEXT AND OBJECTIVE: Peak height velocity (PHV) is an important maturational event during adolescence that affects skeleton size. The objective here was to compare bone variables in adolescents who practiced different types of sports, and to identify whether differences in bone variables attributed to sports practice were dependent on somatic maturation status. DESIGN AND SETTING: Cross-sectional study, São Paulo State University (UNESP). METHODS: The study was composed of 93 adolescents (12 to 16.5 years old), divided into three groups: no-sport group (n = 42), soccer/basketball group (n = 26) and swimming group (n = 25). Bone mineral density and content were measured using dual-energy x-ray absorptiometry and somatic maturation was estimated through using peak height velocity. Data on training load were provided by the coaches. RESULTS: Adolescents whose PHV occurred at an older age presented higher bone mineral density in their upper limbs (P = 0.018). After adjustments for confounders, such as somatic maturation, the swimmers presented lower values for bone mineral density in their lower limbs, spine and whole body. Only the bone mineral density in the upper limbs was similar between the groups. There was a negative relationship between whole-body bone mineral content and the weekly training hours (β: -1563.967; 95% confidence interval, CI: -2916.484 to -211.450). CONCLUSION: The differences in bone variables attributed to sport practice occurred independently of maturation, while high training load in situations of hypogravity seemed to be related to lower bone mass in swimmers.

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