High-sucrose effect on bone structure, hardness and biomechanics in an obesity model using Wistar male rats

Introduction: Excessive consumption of sugar-sweetened beverage is positively related to overweight. Despite the epidemic of childhood obesity, body mass can have a positive or negative effect on bone health. Material and methods: Wistar rats 8 weeks olds were randomly assigned to consume water (Control group, n = 10), sucrose 30% (HS group, n = 10) and water + sucrose 30% (WHS group, n = 14) for 8 weeks. All animals received standard laboratory chow ad libitum. Femur measurements included microhardness, bone mineral density (BMD) by DXA, mechanical compression test and microcomputed tomography (microCT) analysis. Results: We observed significant difference in final body weight in HS and WHS groups, significant increase in triacylglycerol/fructosamine in HS and WHS groups, significantly high BMD in WHS group, increased periosteal/endosteal cortical microhardness in WHS group. Compared with control, microCT parameters evidenced lower amount of connected trabecular bone, decreased bone volume, lower trabecular number with high trabecular separation in distal epiphysis in WHS animals. Conclusion: High-sucrose consumption causes obesity induced by a liquid diet with negative effects on cancellous bone.

O impacto do excesso de gordura corporal sobre a remodelação óssea de adolescentes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fatores de risco para osteoporose em mulheres na pós-menopausa do sudeste brasileiro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Low appendicular muscle mass is correlated with femoral neck bone mineral density loss in postmenopausal women

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bone structure, strength and microhardness resulting after hindlimb unloading in rats

Introduction: Bone strength is influenced by a number of different determinants, such as mass, size, geometry and also by the intrinsic material properties of the tissue. Aims: The structure and mechanical properties of the femur were analyzed in aged (14 mo-old) animals submitted to hindlimb unloading (HU) for 21 days. Methods: Twenty Wistar rats were randomly divided into Control and HU groups and the femur was submitted to dual X ray absorptiometry (DXA), DIGORA radiographic density, mechanical compression testing and Knoop microhardness analyse in cortical and cancellous bone. Results: Femurs from HU group presented significantly lower failure load, decreased bone mineral density (BMD)/bone mineral content (BMC) in whole bone; proximal/distal epiphysis and middiaphyseal cortical bone measured by DXA were similar in the two groups; radiographic density from areas in proximal epiphysis was significantly lower in HU group, and microhardness measured at periosteal and endosteal levels were also signifcantly diminished in HU compared with Control group. Conclusion: Disuse induced damage in the trabecular femoral bone architecture with decisive effect on the head and trochanteric fossa, which became weaker. Bone diaphyseal cortical hardness also suffered effect of unloading, probably related to osteocyte/osteoblast activity.

Capacidade funcional, composição corporal e condições de saúde de idosos longevos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação dos fatores de risco para osteoporose em mulheres na pós-menopausa

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do equilíbrio postural em mulheres na pós-menopausa e sua relação com a densidade mineral óssea

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relationship between bone ageand pubertal breast stage to bone biomarkers and bone mineral density in healthy brazilian female adolescents

Background and Aims Bone metabolism involves understanding many factors, especially during puberty, when bone turnover is significant and the bone mass peak must be achieved as a protective factor of future bone health. The objective was to evaluate the behavior of formation and resorption bone biomarkers (BB) in function of biological maturation in female adolescents.Methods Evaluation of formation and resorption BB, osteocalcin (OC), bone alkaline phosphatase (BAP) and carboxyterminal telopeptide (S-CTx) by correlating them with bone mineralization, bone age and pubertal development in healthy female adolescents. Seventy-two volunteers were subdivided into groups according to chronological age/bone age (BA): 10 11 years (n=12), 12 13 years (n=16), 14 15 years (n=15) and 16 19 years (n=29). The following were evaluated: weight (kg), height (m), BMI (kg/m2), calcium intake (3-day 24h food recalls (mg/day), puberty events (Tanner stages), serum OC (ng/mL), BAP (U/L), S-CTx (ng/mL) and bone mineral density (BMD) as calculated by DXA (g/cm2) in the spine (L1-L4), proximal femur and whole body. The project was approved by the UNESP Ethics Committee.Results BB showed similar behaviors, with higher mean values for 10 12 years and when adolescents were in the B2-B3 Pubertal Maturation Stage (B2: BAP=110.16 U/L, OC=33.81ng/mL, S-CTx=1.66 ng/mL and B3: BAP=136.50 U/L, OC=39.15ng/mL and S-CTx=1.88 ng/mL; p<0.001). Mean BB values decreased with advancing BA and pubertal maturity.Conclusions BB values showed parallelism with peak height velocity and significant negative correlation with BMD in the different evaluated sites, with chronological and BA ; higher BMD values correlated with lower bone biomarker values.

Hindlimb unloading producing effects on bone biomechanical properties in mature male rats

Aging is associated with decline in muscle mass and strength and reduced bone density. Age-related bone loss is a primary factor in osteoporosis and all individuals are potential candidates for osteoporosis because bone loss with aging occurs in men and women, but less studied in men. To examine the appropriateness of hindlimb elevation, by tail suspension as a model for diminished mechanical loading, and to determine the influence of age on bone responsiveness to skeletal unloading, we use dual X ray absorptiometry (DXA) and digital radiographic images to analyze the response of the femur from mature rats to biomechanical loads. Femurs from male Wistar rats (9-mo-old) were scanned using DXA and DIGORA and measures obtained in ephipyseal and diaphyseal regions of interest. The mechanical testing was divided into compression load to fracture the head and a three-point bending load to fracture the femur middiaphysis. In femoral epiphysis from hindlimb unload (HU), animals presented significant differences between mineral bone content and density assessed by DXA. Detailed regions of femoral epiphysis (head, throcanteric fossa, throcanter and metaphysis) presented significant lower values from radiographic density. Only compressive load necessary to fracture the femoral head neck was also significantly diminished in HU animals. Disuse induced, as in elderly patients, deterioration of the trabecular bone architecture with critical effect on bone fragility. Rats with 21 days of hindlimb unloading can simulate disuse, suggesting that certain sub-regions of their aging bones are more susceptible to fracture, while other, i.e. diaphyses, are not.

Prevalência da baixa densidade mineral óssea em mulheres na pós-menopausa tratadas de câncer de mama

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Combined training (aerobic plus strength) potentiates a reduction in body fat but demonstrates no difference on the lipid profile in postmenopausal women when compared to aerobic training with a similar training load

The aim of this study was to verify the effects of aerobic and combined training on the body composition and lipid profile of obese postmenopausal women and to analyze which of these models is more effective after equalizing the training load. Sixty five postmenopausal women (age=61.0±6.3 years) were divided into three groups: Aerobic Training (AT,n= 15), Combined Training (CT,[strength+aerobic],n=32) and control group (CG,n=18). Their body composition: upper body fat (TF), fat mass (FM), percentage of fat mass and fat free mass (FFM) were estimated by DXA. The lipid profile, total cholesterol, HDL-cholesterol and LDL-cholesterol were assessed. There was a statistically significant difference in the TF (AT= -4.4 %, CT= -4.4%, and CG= 1.0%, p= 0.001) and FFM (AT= 1.7%, CT= 2.6%, and CG= -1.4%, p= 0.0001) between the experimental and the control groups. Regarding the percentage of body fat, there was a statistically significant difference only between the CT and CG groups (AT= -2.8%, CT= -3.9% and CG= 0.31%, p= 0.004). When training loads were equalized, the aerobic and combined training decreased core fat and increased fat-free mass, but only the combined training potentiated a reduction in percentage of body fat in obese postmenopausal women after the training program. HDL-c levels increased in the combined group and the chol/HDL ratio (atherogenic index) decreased in the aerobic group, however, there were no significant differences between the intervention programs. Taken together, both the exercise training programs were effective for improving body composition and inducing an anti-atherogenic status.

Custo energético durante a prática do Kendō e proposição de protocolo específico para avaliação da aptidão aeróbia em praticantes

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Evaluation of femur of orchiectomized guinea pigs by bone densitometry using dual-energy x-ray absortiometry (DXA) and mechanical testing

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise preditiva da densidade mineral óssea em adolescentes brasileiros eutróficos do sexo masculino

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)