Volume 3 · Number 4 · December 2011
- Isoflavones and bone [137-138]
- Changes in bone metabolism markers and ultrasound parameters in postmenopausal women induced by soy isoflavones [141-146]
- Usefulness of FRAX® in the study of fractures in the alcoholic patient [149-156]
- Risk of fracture according to FRAX®, hypovitaminosis D, and quality of life in a population with osteoporotic fracture cared for in primary care: baseline description of the VERFOECAP cohort [157-164]
- Nutrition and osteoporosis. Calcium and vitamin D [165-182]
- Profile of action of denosumab in treatment of osteoporosis [183-188]
The appearance of scales for the prediction of the absolute risk of fragility fracture and the consequent definition of thresholds for pharmacological intervention has significantly limited the number of women eligible for treatment among those who are in their first years of the menopause. What is certain is the deterioration that many of them suffer in terms of bone metabolism as a consequence of rapid hypogonadism, but there are no defined strategies for the use of drugs to limit this phenomenon. In its day, hormone therapy solved this problem, but its limitations to use in women with symptoms sufficient to affect quality of life has left many users without an efficacious option. It is true that life style changes, especially diet and exercise, alleviate the problem, but they are not an entirely satisfactory solution. The advances which are being made in the action mechanism of plant extracts, both in the form of pure molecules prepared to the equal quality of medicines, or foods in which they are found in sufficient concentrations (functional foods), are raising new expectations. There has been significant progress in the knowledge of the molecular mechanisms of many of these substances, especially the isoflavones. Although there are differences between their components, we know that they are capable of activating estrogen receptors, particularly isoform β, and that this is followed by the activation of different signalling pathways in various experimental models, essentially cellular. The fundamental question, however, is what is their true clinical significance.
On this point the evidence is more limited and to date, still confusing. On the one hand is the unfinished business of the symptoms, where there are few clinical studies of quality, and those that there are present difficulties derived from their inclusion of groups with low numbers of participants or of other methodological drawbacks. On the other, there is the question of their eventual efficacy in limiting chronic diseases which more or less clearly have their roots in hypogonadism, such as cardiovascular disease or osteoporosis. The questions in relation to the former have recently been reviewed1, and with respect to the latter, particularly welcome is the article by García-Martín et al. in this issue2.
Changes in bone metabolism markers and ultrasound parameters in postmenopausal women induced by soy isoflavones
Introduction: The results of the works published on the role of isoflavones in the prevention of postmenopausal osteoporosis are contradictory. The objective of our study is to evaluate the effects of nutritional intervention with a milk product enriched with soy isoflavones on bone metabolism in Spanish postmenopausal women.
Subjects and methods: A randomised controlled double blind trial was carried out in 99 postmenopausal women who were allocated to two groups: group S (n=48), with a consumption of a milk product enriched with soy isoflavones (50mg/day), and group C (n=51), with a consumption of a control milk product over 12 months. Hormone parameters and markers for bone metabolism were assessed at the baseline and at one year. Ultrasound of the calcaneum (QUS, Hologic Sahara®, North Carolina, US.) was used as the evaluation tool for bone mass.
Results: At 12 months, a decrease in blood levels of tartrate-resistant acid phosphatase and osteoprotegerin occurred (2.18 ± 0.8 vs 1.76 ± 0.54 U/l, p<0.001, and 5.21 ± 3.36 vs 3.89 ± 1.47 pmol/L, p=0.007, respectively), as well as an increase in 25-OH-vitamin D (24.48 ± 9.85 vs 28.18 ± 10.45 ng/ml, p<0.001 ) with no differences between the groups. There were no significant changes in hormone parameters and the rest of the bone markers. In terms of the QUS, in the total sample there was an increase in the sound velocity [SOS] (1517.86 ± 38.13 vs 1525.11 ± 35.6 m/s, p=0.036), QUI (76.37 ±19.87 vs 80.82 ± 18.26, p=0.012 ), estimated bone mineral density [Est. BMD] (0.408 ± 0.13 vs 0.435 ± 0.12 g/cm², p=0.013) and T-score (-1.55 ± 1.12 vs -1.31 ± 1.03, p=0.019). In group S, positive changes occurred in QUI (74.37 ± 18.87 vs 78.83 ± 13.68, p=0.032) and Est. BMD (0.397 ± 0.12 vs 0.423 ± 0.09 g/cm², p=0.04), whilst in group C there were no significant differences.
Conclusions: The daily consumption of these milk products increases levels of 25-OH-vitamin D and results in a decrease in markers for bone metabolism. A diet rich in soy isoflavones may be an option as a preventative measure against the effects of the menopause on bone.
FRAX® index is a prognostic tool to assess the risk of osteoporotic fracture. Although ethanol ingestion, liver disease and body mass index are considered independent prognostic factors in the FRAX® score, we have observed that in chronic alcoholics there are several variables not included in the FRAX® index, which show a relation with prevalent fractures and/or low BMD. Therefore, in this study we compare the relation of FRAX® index with those of other variables, such as lean and fat mass, liver function parameters, and amount of ethanol consumed, with the presence or not of prevalent fractures in 57 chronic alcoholic men, older than 40 years, drinkers of more than 200 g ethanol/day during a long time. We found that FRAX® index was significantly higher among those with any fracture, but the same happened with BMI, total fat amount, and fat amount at arms, as well as total amount of ethanol. The FRAX® index did not show differences among those with or without vertebral fractures, or rib fractures. Patients with rib fractures showed differences in total fat amount and right arm fat amount when compared with patients without rib fractures. Therefore, these results suggest that in the alcoholic, other variables, such as amount of ethanol consumed and fat mass, should be considered, in addition to FRAX®, in the prediction of fractures.read more
Risk of fracture according to FRAX®, hypovitaminosis D, and quality of life in a population with osteoporotic fracture cared for in primary care: baseline description of the VERFOECAP cohort
Background: the patient with an osteoporotic fracture cared for in primary care has seldom been studied. The VERFOECAP study has dual objectives: to estimate if the risk of fracture (FRAX®) in fractured patients is different in patients with or without a re-fracture; and to study the prevalence of hypovitaminosis D and the impact of the fracture on quality of life. We present a baseline description.
Material and method: design and ambit: multicentred prospective cohort study in primary care (12 centres in Catalonia). Population: random sample of patients with a history of principal osteoporotic fracture between 2006 and 2008 cared for in primary care. Information gathering: at initial inclusion meetings clinical information was gathered, quality of life questionnaires ECOS16 (specific) and EuroQol-5D (generic) completed, spinal X-ray carried out, and levels of vitamin D in the blood measured. Subjects were followed up for two years. Analysis: comparison between two groups using T-test or chi-squared test. Prevalence of hypovitaminosis D and confidence interval using binomial test.
Results: 194 patients were included. The average risk (standard deviation) of fracture of the hip, according to FRAX® was calculated as: 6.9% (6.4), and of principal osteoporotic fractures: 14.8% (8.6). EuroQol-5D showed frequent limitations to walking (47.6%) and to daily activities (45.5%); 55.0% reported moderate pain, and 41.0% anxiety/depression. The ECOS-16 score was higher in patients with a history of vertebral fracture (p<0.001). The prevalence of hypovitaminosis D was 61.4% (CI 95%: 53.6%-68.9%).
Conclusions: the VERFOECAP cohort includes patients with osteoporotic fractures cared for in primary care at high risk of re-fracture with significant deterioration in quality of life. In these patients vitamin D deficiency is highly prevalent.
Calcium and vitamin D are essential nutritional elements in bone health throughout life, in the attainment and maintenance of peak bone mass. In the treatment of osteoporosis, an adequate intake of calcium and the repletion of vitamin D are critical for the maximisation, in terms of antifractural efficacy, of the response to osteo-active treatments: anticatabolics and anabolics.
The daily requirement for calcium is estimated to be between 1,000 and 1,200 mg and may be obtained relatively easily through a normal diet, or by means of food supplements. However, a substantial section of the population does not attain these required levels. In addition, patients with intolerance to milk, with limited gastric secretion due to their age, for autoimmune reasons, or due to the use of agents such as proton pumps which limit it, gastrectomy or other reasons, or malabsorption, make calcium supplements, nutritional or pharmacological, necessary. The requirements for vitamin D are estimated at 800-1,000 UI, but few foods contain this vitamin, and cutaneous synthesis, even in sunny regions, is insufficient to obtain blood levels of 25 (OH)D [marker for the status of vitamin D in the body] above the 30 ng/mL necessary for an optimum biological response in the bone and other target organs and tissues. This means that it is practically always necessary to supplement it through reinforced foods or with pharmacological vitamin D.
The recent discovery of the RANK/RANKL/OPG system (RANK: Receptor Activator for Nuclear Factor κB; RANKL: Receptor Activator for Nuclear Factor κB Ligand; OPG: osteoprotegerin) as final effector in osteoporosis pathogenesis have lead to the development of new therapeutic strategies. Denosumab is a human monoclonal antibody that, like OPG, binds to RANKL preventing RANK activation, thus decreasing bone turnover and increasing bone mineral density. Denosumab is administered subcutaneously every 6 months. Clinical trials have demonstrated efficacy on bone mineral density and reduction of fractures in postmenopausal women and a favourable safety profile.read more
Since the first, the Journal of Savançs, was published in 1665, scientific reviews have been the vehicles par excellence for the spreading of information and scientific knowledge, and instruments of communication between researchers from the same field. In the general framework of scientific communication “authors resort to the scientific journals with intention of ensuring ownership of their ideas (a public register) and with the certainty that the knowledge published is valid, is scientifically verified and respects the academic norms of scientific method, and this because it has been evaluated fairly and impartially by the members of the scientific community themselves, thus becoming an instrument of certification, validation and knowledge”1.
The importance of scientific reviews reaches its greatest expression in the case of medicine, where they are the medium most used for the interchange of ideas, to review and to update knowledge, making them a true reflection of the evolution of this scientific community.
Since their appearance in the 17th century, the evolution of scientific reviews has been linked with the changes in the way science is conducted and especially, to the events in the purely technological realm. In recent years, especially since the appearance and spreading use of the internet in the 90s, and after its consolidation as the main medium for searching for information and spreading content, we are experiencing great transformations in the process of scientific communications which directly affect the way in which reviews are written and published: the step from the printed form to the electronic, the appearance and consolidation of the Open Access movement which has modified the way scientific knowledge is published, spread and visualised, and the incorporation in the scientific reviews of the technologies of the so-called Web 2.0, “a system of applications on the internet which can be integrated to facilitate the publication of content by the users”2, turning it into more attractive products for the final user. All this has produced significant changes in the editorial guidelines of scientific publications, as well as in the way of consulting with, and participating in, these journals. I think that these conditions make this the time for reflexion and to try to give a response to questions such as: Will the print media survive or will the digital format definitely take over? Will the reviews be accessible by subscription or free access? Will the reviews be 2.0?
Taking into account how, and by how much, the scientific communication scene has transformed in recent years, the difficulty associated with predicting how scientific reviews will be in just a few years will have escaped no one, but we attempt here to give some broad brushstrokes to give us a glimpse, at least, of the general picture.
Elevated prevalence of hypovitaminosis D in a population attending a health centre in Tenerife, Canary Islands
To the Editor:
The existence of hypovitaminosis D in the population is well known, both in the general population and in certain groups of patients [1,2], being most significant in older people who are institutionalised in residential homes .
The Canary Islands, being an archipelago with a large number of hours of sun and, therefore, with a high availability of what constitutes the natural source of vitamin D, might be expected to have a low prevalence of hypovitaminosis D expected in its population. However, various studies in our environment have confirmed that levels of vitamin D are as low as those in other areas of Spain situated further north [4-8]. Hence, highly notable is a study carried out in Canarian medical students who, being young, healthy and with sufficient knowledge of the physiology of vitamin D, and even though spending a large number of hours in the sun, still had a high prevalence of hypovitaminosis D .