Polycystic ovary syndrome (PCOS), characterized by ovarian androgen excess, is the commonest endocrine disorder in women. Obesity increases androgen synthesis, a phenomenon attributed to the accompanying hyperinsulinemia. Our hypothesis was that adipokines, fat cell-derived hormones, play a direct role in modulating ovarian androgen secretion. Therefore, the aims of this study were to explore the effects of adipokines (in particular, adiponectin) on ovarian steroidogenesis and compare the expression of adiponectin receptors in ovaries from women with and without PCO. Sections of archived human ovaries (nine from women with normal ovaries and 16 with PCOS, classified histologically, with reference to menstrual history and ultrasound) were analysed by quantitative morphometry and the proportion of positive-labelling cells compared. In addition, studies of androgen production in relation to adipokine function in primary bovine theca cell culture were also performed. A significantly lower proportion of theca cells expressed adiponectin receptors 1 and 2 (AdipoR1, AdipoR2) in polycystic ovaries than in normal ovaries. In cultured theca cells, adiponectin suppressed androstenedione production and gene expression of LH receptor and key enzymes in the androgen synthesis pathway. Moreover, knockdown of genes for AdipoR1 and AdipoR2 was associated with increased androstenedione secretion by bovine theca cells. These results provide evidence for a direct link between fat cell metabolism and ovarian steroidogenesis, suggesting that disruption of adiponectin and/or its receptors plays a key role in pathogenesis of hyperandrogenism in PCOS.
Until recently obesity was believed to be protective against fractures. However, a report from a Fracture Liaison Clinic in the UK (2010) reported a surprisingly high proportion of obese postmenopausal women attending the clinic with fractures, and in the GLOW study (2011), a similar prevalence and incidence of fractures in obese and non-obese postmenopausal women was observed. Subsequently, other studies have demonstrated the importance of obesity in the epidemiology of fractures. Obese women are at increased risk of fracture in ankle, leg, humerus, and vertebral column and at lower risk of wrist, hip and pelvis fracture when compared to non-obese women. In men, it has been reported that multiple rib fractures are associated with obesity. Furthermore, falls appear to play an important role in the pathogenesis of fractures in obese subjects. Regarding hip fracture and major fractures, the FRAX algorithm has proven to be a useful predictor in obese individuals. Obese people are less likely to receive bone protective treatment; they have a longer hospital stay and a lower quality of life both before and after fracture. Moreover, the efficacy of antiresorptive therapies is not well established in obese people. The latter is a field for future research. Arq Bras Endocrinol Metab. 2014;58(5):470-7 Keywords Obesity; fractures; osteoporosis; osteopenia ReSumo Acreditava-se que pessoas obesas estavam protegidas contra fraturas. No entanto, um estudo realizado no Reino Unido (2010) encontrou uma proporção surpreendentemente alta de obesidade entre as mulheres na pós-menopausa que se consultaram em uma Clínica de Fraturas Ósseas. Da mesma maneira, o estudo GLOW (2011) observou prevalência e incidência semelhantes de fraturas em mulheres na pós-menopausa obesas e não obesas. Posteriormente, vários outros estudos têm demonstrado a importância da obesidade na epidemiologia de fraturas. Mulheres obesas têm maior risco de fratura no tornozelo, na perna, no úmero e na coluna vertebral e têm menor risco de fratura de punho, quadril e pelve quando comparadas às mulheres não obesas. A associação entre fraturas múltiplas de costelas e obesidade foi descrita em homens. Além disso, as quedas parecem desempenhar um papel importante na patogênese de fraturas em pacientes obesos. O algoritmo FRAX parece ser uma ferramenta útil na predição do risco de fraturas em indivíduos obesos. Indivíduos obesos são menos propensos a receber tratamento preventivo para as fraturas ósseas e, quando sofrem uma fratura óssea, sua internação costuma ser mais longa do que a internação de indivíduos magros. A qualidade de vida dos indivíduos obesos é menor antes e depois da fratura. Não obstante, a eficácia de terapias antirreabsorção não está bem estabelecida em pessoas obesas. Este último é um campo para pesquisas futuras. Arq Bras Endocrinol Metab. 2014;58(5):470-7 Descritores Obesidade; fraturas ósseas; osteoporose, osteopenia
Background Although intake of fruits and vegetables seemed to have a protective effect on bone metabolism, its effect on fractures remains uncertain. Methods A systematic review of randomized controlled trials (RCTs) and cohort studies (PROSPERO: CRD42016041462) was performed. RCTs and cohort studies that evaluated the combined intake of fruits and vegetables in men and women aged over 50 years were included. We considered fractures as a primary outcome measure. Changes in bone markers were considered as secondary outcomes. The search strategy included the following descriptors: fruit, vegetables, vegetable products, bone and bones, bone fractures, postmenopausal osteoporosis, and osteoporosis. PubMed, Embase, and Cochrane Library were the databases used. The appraisal of the studies was performed by two independent reviewers, and discussed and agreed upon by both examiners. The data extracted from the RCTs and cohort studies were summarized separately. The risks of fractures were combined across studies using random models. Bone resorption marker (CTx) was summarized with standardized mean differences. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) method was used to evaluate the strength of recommendations. Results Of the 1,192 studies screened, 13 articles were included in the systematic review and 10 were included in the pooled analysis (6 cohort studies and 4 RCTs). The six cohort studies included in the meta-analysis included a population of 225,062. The pooled hazard ratio (HR) (95% confidence interval (CI)) of the hip in five studies was 0.92 (0.87, 0.98). Its heterogeneity was moderate (I 2 = 55.7%, p = 0.060), GRADE ( ⊕⊕⊕ O). Two cohort studies evaluated the risk of any fracture; the HR was 0.90 (95% CI: 0.86–0.96), with aheterogeneity of 24.9% (p = 0.249, GRADE ( ⊕⊕⊕ O)). There was no association between the bone resorption marker CTx and 3 months of fruit and vegetable intake evaluated by four RCTs, GRADE ( ⊕⊕ O O). Conclusion There was an association between the increase of at least one serving of fruits and vegetables per day and decreases in the risk of fractures. The level of evidence for this association is moderate.
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