Association between handgrip strength and body composition, physical fitness, and biomarkers in postmenopausal women with metabolic syndrome

SUMMARY OBJECTIVES: This study examined the association between handgrip strength and body composition, physical fitness, and biomarkers in postmenopausal women with metabolic syndrome. METHODS: A total of 75 postmenopausal women were diagnosed with metabolic syndrome participated in this study. Muscle strength was assessed via a hydraulic grip strength dynamometer; physical fitness tests included a timed-up-and-go, arm curl test, and 30-s chair stand. Body composition was assessed via bioelectrical impedance, from which estimates of fat mass, body fat percentage, fat-free mass, and visceral fat area were determined. Fasting plasma glucose and glycated hemoglobin were measured via blood sample analyses. Multiple linear regression analyses were conducted using handgrip strength as the dependent variable and using body composition, physical fitness, and biomarkers as independent variables. RESULTS: The results revealed that 52% of the total sample were classified as obese, 37.3% as overweight, and only 10.7% as normal weight. Significant correlations were present between handgrip strength and fat-free mass (p=0.002; R=0.590), mean blood pressure (p=0.002; R=0.450), and arm curl (p=0.001; R=0.795). CONCLUSION: This study showed that handgrip strength was predictive of fat-free mass, blood pressure, and upper limb strength performance.

Are skeletally mature female rats a suitable model to study osteoporosis? / Ratas esqueleticamente maduras são um modelo satisfatório para estudar osteoporose?

OBJECTIVE: To analyze if female Wistar rats at 56 weeks of age are a suitable model to study osteoporosis. MATERIALS AND METHODS: Female rats with 6 and 36 weeks of age (n = 8 per group) were kept over a 20-week period and fed a diet for mature rodents complete in terms of Ca, phosphorous, and vitamin D. Excised femurs were measured for bone mass using dual-energy x-ray absorptiometry, morphometry, and biomechanical properties. The following serum mar-kers of bone metabolism were analyzed: parathyroid hormone (PTH), osteocalcin (OC), osteoprotegerin (OPG), receptor activator of nuclear factor Κappa B ligand (RANKL), C-terminal peptides of type I collagen (CTX-I), total calcium, and alkaline phosphatase (ALP) activity. RESULTS: Rats at 56 weeks of age showed important bone metabolism differences when compared with the younger group, such as, highest diaphysis energy to failure, lowest levels of OC, CTX-I, and ALP, and elevated PTH, even with adequate dietary Ca. CONCLUSION: Rats at 26-week-old rats may be too young to study age-related bone loss, whereas the 56-week-old rats may be good models to represent the early stages of age-related changes in bone metabolism.

OBJETIVO: Avaliar se ratas Wistar com 56 semanas de idade são um modelo satisfatório para estudar osteoporose. MATERIAIS E MÉTODOS: Ratas com 6 e 36 semanas de idade (n = 8 por grupo) foram criadas por um período de 20 semanas e alimentadas com dieta completa em Ca, fósforo e vitamina D para ratas adultas. Os fêmures foram analisados quanto à massa óssea pela técnica de absortiometria por dupla fonte de raios-X, morfometria e propriedades biomecânicas; os marcadores séricos do metabolismo ósseo analisados foram paratormônio (PTH), osteocalcina (OC), osteoprotegerina (OPG), fator receptor ativador nuclear Κappa B ligante (RANKL), peptídeos C-terminal de colágeno tipo I (CTX-I), cálcio total e atividade da fosfatase alcalina (FA). RESULTADOS: As ratas com 56 semanas de vida apresentaram uma importante diferença no metabolismo ósseo quando comparadas ao grupo das ratas jovens, como, por exemplo, maior energia para quebrar a diáfise do fêmur, menores níveis de OC, CTX-I e ALP e maiores níveis de PTH mesmo com dieta adequada em cálcio. CONCLUSÃO: As ratas com 26 semanas de vida podem ser consideradas muito jovens para estudar a perda óssea relacionada à idade, porém, as ratas com 56 semanas de vida podem representar um bom modelo dos estágios iniciais das alterações associadas à idade no metabolismo ósseo.

Fructooligosaccharides (FOS) and hormonal replacement therapy (HRT) by estrogen suppressed bone resorption in the ovariectomized rat

The present investigation aims to compare the effects of fructooligosaccharides (FOS) and the hormonal replacement therapy (HRT) by estrogen on bone metabolism in ovariectomized rats. Three-month-old (276,0±3,4g body weight) Wistar female rats were submitted to an ovariectomy (OVT) procedure and after 30 days, the animals were randomLy assigned (n=10) to treatment groups for 20 days. The animals were treated with FOS (RAFTILOSE® P95) (5g/100g of diet intake/day) through intragastric intubations and/or not with hormonal replacement therapy (HRT) by synthetic â-estradiol (SIGMA/E-4389) (30ìg/kg of body weight) daily administrated by subcutaneous injection (G1 = OVT + FOS + HRT; G2 = OVT + FOS + saline; G3 = OVT + water + HRT; G4 = OVT + water + saline). The rats were fed with standard diet contend 1.3 por cento of Ca and received deionized water ad libitum. The data are expressed as the mean values ± standard error means (SEM) and analyzed by two-way ANOVA Tukey’s post-hoc test (p<0.05). Both treatments alone reduced total alkaline phosphatase activity. The FOS treatment increased the tibiae calcium, but the effect of FOS + HRT was more powerful. Radiodensity analysis supports this result too. In femur biomechanical properties, the proportional limit and resilience of FOS + HRT and FOS animals group suggest an increased effect on the bone capacity in absorbing energy. These results are also observed in the qualitative analysis of the SEM. Prebiotics substances consumption should be introduced for prevention or treatment of osteoporosis.