Effect of self-reported walking difficulty on bone mass and bone resorption marker in Japanese people aged 40?years and over

Background: This study aimed to examine the association of walking difficulty with bone mass or bone turnover among community-dwelling Japanese people aged 40 years and older. Methods: We studied 1097 community-dwelling Japanese people aged 40 years and older (379 men and 718 women) who were invited to participate in periodic health examinations in 2006?2009. Walking difficulty was defined as having difficulty walking 100 m on a level surface (self-administered questionnaire). Calcaneal stiffness index (bone mass) was measured by quantitative ultrasound. Spot urine samples were collected, and urinary N-terminal cross-linking telopeptide of type I collagen (NTx) was measured. Values were corrected for creatinine (Cre) concentration. Results: The prevalence of walking difficulty was significantly higher in women than in men (7.4 vs. 3.4 %, p?=?0.011) and significantly increased with age in men (p for trend?=?0.02) and women (p for trend <0.001). In univariate analysis, men and women with walking difficulty were older (p?<?0.001) and had a lower stiffness index (p?<?0.001), compared with those without walking difficulty. Among women, individuals with walking difficulty had significantly higher urinary NTx/Cre than those without walking difficulty (p?<?0.001); however, this was not so among men (p?=?0.39). Multiple regression analysis adjusted for age, weight, and menopausal status showed a significant association between walking difficulty and lower stiffness index in men (p?=?0.004) and women (p?=?0.005). In women, walking difficulty was significantly associated with higher NTx/Cre (p?=?0.001), but not in men (p?=?0.35). Conclusions: Walking difficulty may contribute to low bone mass in both sexes but might cause high bone turnover in women only

Relationship between oxidative stress and diabetic osteopenia in premenopausal rats

The relationship between lipid peroxidation, antioxidant defense and diabetic osteopenia remains unclear. This study evaluated the relationship among lipid peroxidation index, antioxidant defense parameters and bone metabolism in a premenopausal diabetic model using measures including thiobarbituric acid-reactive substances concentration (TBARS) and reduced glutathione (GSH) content in brain homogenates, histomorphometric analysis, biomechanical testing and bone mineral density (BMD). Female Wistar rats with regular estrous cycle were divided into two groups: Group 1: control rats (n = 15) and Group 2: diabetic rats (n = 15). Diabetes was induced by alloxan and confirmed by glycemia >250 mg/dL. The lipid peroxidation index, measured by TBARS concentration, showed a significant increase (p<0.05) in diabetic animals in comparison to control animals. However, the antioxidant parameter measured by GSH content, was significantly lower (p<0.05) in diabetic animals. Histomorphometric analysis showed a significant increase (p<0.05) in femoral trabecular separation together with a significant decrease (p<0.05) in trabecular thickness, and reduced trabecular bone volume in diabetic rats. Moreover, biomechanical testing and BMD values were significantly lower (p<0.05) in the diabetic group. Thus, our results demonstrated that increased lipid peroxidation and altered antioxidant defense could be related to the development of oxidative stress and diabetic osteopenia in premenopausal rats.<br>A relação entre peroxidação lipídica, defesa antioxidante e osteopenia diabética permanece obscura. Este estudo avaliou a associação entre índice de peroxidação lipídica, parâmetro de defesa antioxidante e metabolismo ósseo em um modelo diabético pré-menopausa através de medidas como a concentração de substâncias reativas ao ácido tiobarbitúrico (SRAT) e conteúdo de glutationa reduzida (GSH) no homogenato cerebral, análises histomorfométricas, teste biomecânico e densidade mineral óssea (DMO). Ratos Wistar fêmeas com ciclo estral regular foram distribuídos em dois grupos: Grupo 1 - ratas controle (n = 15) e Grupo 2 - ratas diabéticas (n = 15). O diabetes foi induzido pela aloxana e confirmado pela glicemia >250 mg/dL. O índice de peroxidação lipídica, medido pela concentração de SRAT, demonstrou um aumento significativo (p<0.05) nos animais diabéticos, em relação aos animais controle. Entretanto, o parâmetro de defesa antioxidante, mensurado pelo conteúdo de GSH, foi reduzido significativamente (p<0.05) nos animais diabéticos. As análises histomorfométricas mostraram um aumento significativo (p<0.05) da separação trabecular do fêmur, associado à diminuição significativa da espessura trabecular (p<0.05) e volume ósseo trabecular reduzido nas ratas diabéticas. Além disso, o teste biomecânico, medido pela força máxima, e valores de DMO foram reduzidos significativamente (p<0.05) no grupo diabético. Dessa maneira, nossos resultados demonstraram que a peroxidação lipídica aumentada e defesa antioxidante modificada podem estar relacionadas ao desenvolvimento do estresse oxidativo e osteopenia diabética em ratas pré-menopausadas