Skin Cancer Prevention Strategy and Action Plan (PDF 455KB)

Northern Ireland may not enjoy the sunniest climate in the world, or even in the UK, however, in spite of this we have witnessed a significant rise in the incidence of melanoma skin cancer cases in recent years - from 80 cases in 1984 to 282 in 2009 (the latest year for which published figures are available). In relation to non-melanoma skin cancers, there are approximately 2,850 new cases here each year, making it the most common type of cancer diagnosed in Northern Ireland. åÊ The rise in the number of skin cancer cases is alarming. We know that the increase in this particular type of cancer is global and not just confined to our part of the world. We also know there are many factors involved: the significant rise in people travelling on foreign sun holidays; more leisure time being spent out of doors; and damage caused to the ozone layer to name but a few. åÊ Substantial progress in the area of skin cancer awareness raising and prevention has been made through the previous “Melanoma Strategy” which was developed in 1997. However, the unfortunate reality is that we will continue to see rising rates of skin cancer for some time to come as a result of many years of overexposure to the sun before skin cancer prevention programmes were developed. Until we can reverse this trend through effective campaigning and awareness raising, early detection will be key to bringing down mortality rates. While the 1997 strategy was right for its time, there have been many developments since then, necessitating a new strategy to reflect today’s position. åÊ For example, recent studies about the importance of vitamin D have highlighted the need for balance in sun safety messages. This new strategy is not about stopping people from enjoying the sun and its many benefits. Rather, it is about encouraging people to take proportionate measures to prevent overexposure. åÊ åÊ

Bone anabolic potential of soy isoflavones and plant extracts and genomic changes during differentiation of hPOB-tert osteoblast-like cells

Summary For the nutritional management of bone health and the prevention of osteoporosis it is important to identify nutrients that positively influence the bone remodeling process at the cellular level. Soy isoflavones show promising osteoprotective effects in animals and humans but their mechanism of action in bone cells is yet poorly understood. Firstly, soy tissue cultures were characterized as a new and optimized source of isoflavones. A large variability in the isoflavone content was observed and high-producing strains (46.3 mg/g dry wt isoflavones) were identified. In the Ishikawa cells bioassay, the estrogenicity of isoflavones was confirmed to be 1000 to 10000 less than 17Mestradiol and that of the malonyl forms was shown for the first time (EC50 of 350 nM and 1880 nM for malonylgenistin and malonyldaidzin, respectively). The estrogenic activity of soya tissue culture extracts correlated to their isoflavone content. Secondly, the effects of phytonutrients on BMP-2 gene expression and on the mevalonate synthesis pathway, as key mediators of bone formation, were investigated. Dietary achievable concentrations of genistein and daidzein (10vM), and statins (4xM) but not 17M estradiol (10nM), induced BMP-2 gene expression (by up to 3-fold) and inhibited the cholesterol biosynthetic pathway (by up to 50%) in the human osteoblastic cell line hP0B¬tert. In addition, several plant extracts (Cyperus rotundus, Lindera benzoin and Cnidium monnieri) induced BMP-2 gene expression but this induction was not restricted to the inhibition of the cholesterol synthesis pathway neither to the estrogenicity. Finally, the gene expression profiles during hP0B-tert differentiation induced by vitamin D and dexamethasone were analyzed with the Affymetrix human GeneChip. 1665 different genes and 98 ESTs were significantly regulated. The expression profiles of bone-related genes was largely in agreement with previously documented patterns, supporting the physiological relevance of the genomic results and the hP0B-tert cell line as a valid model of human osteoblast differentiation. The expression of alternative differentiation markers during the osteogenic treatment of hP0B-tert cells indicated that the adipocyte and myoblast differentiation pathways were repressed, confirming that these culture conditions allowed only osteoblast differentiation. The gene ontology analysis identified further sub-groups of genes that may be involved in the bone formation process. Aims of the thesis In order to define new strategies for the nutritional management of bone health and for the prevention of osteoporosis the major goal of the present work was to investigate the potential of phytonutrients to positively modulate the bone formation process at the cellular level and, in particular: 1.To select and optimise alternative plant sources containing high levels of isoflavones with estrogenic activity (Chapter 3). 2.To compare the effects of statins and phytonutrients on BMP-2 gene expression and on the mevalonate synthesis pathway and to select new plant extracts with a bone anabolic potential (Chapter 4). 3.To further characterize the new human periosteal cell line, hP0B-tert, as a bone- formation model, by elucidating its gene expression profile during differentiation induced by vitamin D and dexamethasone (Chapter 5).

Malignant transformation of DMBA/TPA-induced papillomas and nevi in the skin of mice selectively lacking retinoid-X-receptor alpha in epidermal keratinocytes.

Retinoid-X-receptor alpha (RXRalpha), a member of the nuclear receptor (NR) superfamily, is a ligand-dependent transcriptional regulatory factor. It plays a crucial role in NR signalling through heterodimerization with some 15 NRs. We investigated the role of RXRalpha and its partners on mouse skin tumor formation and malignant progression upon topical DMBA/TPA treatment. In mutants selectively ablated for RXRalpha in keratinocytes, epidermal tumors increased in size and number, and frequently progressed to carcinomas. As keratinocyte-selective peroxisome proliferator-activated receptor gamma (PPARgamma) ablation had similar effects, RXRalpha/PPARgamma heterodimers most probably mediate epidermal tumor suppression. Keratinocyte-selective RXRalpha-null and vitamin-D-receptor null mice also exhibited more numerous dermal melanocytic growths (nevi) than control mice, but only nevi from RXRalpha mutant mice progressed to invasive human-melanoma-like tumors. Distinct RXRalpha-mediated molecular events appear therefore to be involved, in keratinocytes, in cell-autonomous suppression of epidermal tumorigenesis and malignant progression, and in non-cell-autonomous suppression of nevi formation and progression. Our study emphasizes the crucial role of keratinocytes in chemically induced epidermal and melanocytic tumorigenesis, and raises the possibility that they could play a similar role in UV-induced tumorigenesis, notably in nevi formation and progression to melanoma.

Five Years Of Denosumab Treatment In Women With Postmenopausal Osteoporosis: Preliminary Results From The Freedom Extension Study

Aims: The pivotal FREEDOM study evaluated the effi cacy and safety of 3 years' denosumab treatment in women with postmenopausal osteoporosis (PMO).1 Since osteoporosis is a chronic condition requiring long-term therapy, FREEDOM was extended to further elucidate the safety and effi cacy of long-term denosumab administration. We present data from the fi rst 2 years of this extension, representing up to 5 years' continuous exposure to denosumab.Methods: Patients who completed FREEDOM were eligible for the extension. Women continued to receive (long-term group), or started after 3 years' placebo (cross-over group), denosumab 60 mg sc every 6 months and daily calcium and vitamin D. These data refl ect 5 years' (long-term) or 2 years' (cross-over) continuous denosumab treatment. Effi cacy measures include changes in BMD from extension study baseline and bone turnover markers (BTM). P-values are descriptive.Results: Of the 83.0% of subjects who completed FREEDOM, 70.2% (N = 4550) agreed to participate in the extension (long-term: 2343; cross-over: 2207). In the long-term group, there were further signifi cant gains (P < 0.0001) in BMD in years 4 and 5: 1.9% and 1.7% at the lumbar spine to a total of 13.7% from FREEDOM baseline and 0.7% and 0.6% at the total hip to a total of 7.0%. During their fi rst 2 years' denosumab treatment, women in the cross-over group had signifi cant improvements in lumbar spine (7.9%) and total hip BMD (4.1%) (P < 0.0001). Serum C-telopeptide (CTX) was rapidly reduced following denosumab dosing in both groups, with the characteristic attenuation of CTX reduction observed at the end of the dosing interval. A low incidence of new vertebral and nonvertebral fractures was reported for both groups. The denosumab safety profi le did not change over time.Conclusions: Denosumab treatment for up to 5 years in women with PMO remains well tolerated, maintains reduction of BTMs and continues to significantly increase BMD.Reference1. Cummings. NEJM 2009;361:756.

Pathoecology and paleodiet in Postclassic: Historic Maya from northern coastal Belize

This paper examines the synergism among diet, disease, and ecology at two related coastal Maya sites in Belize (Marco Gonzalez and San Pedro) for the Postclassic and Historic periods (1350-1650 AD), which immediately follow the Classic period collapse. Stable carbon- and nitrogen-isotope ratios in collagen and stable carbon-isotope ratios in structural carbonate were analysed for bones from 65 humans and a wide variety of faunal species. There are no apparent differences in whole diets or degree of carnivory between individuals with lesions indicative of anemia and those without, but those with lesions appear to have consumed significantly more C4 foods and protein from lower trophic levels. Non-specific infection (periostitis) and vitamin C deficiency (scurvy) are also present in high frequencies and appear to co-occur with lesions indicative of anemia, particularly in childhood. Individuals with scurvy also appear to have consumed significantly more C4 foods than normal individuals. Spondyloarthropathy is common in adults. These findings are discussed in light of: (1) the debate on how anemia versus scurvy are manifest and diagnosed, (2) Spanish ethnohistoric descriptions of the poor state of Maya health at the time of contact, and (3) the Osteological Paradox. We suggest that although this coastal environment exacerbated morbidity because of possible parasitic infection, the inhabitants were probably able to survive physiological stresses better than either their inland contemporaries or their modern counterparts.

Calbindin-immunoreactive sensory neurons in dissociated dorsal root ganglion cell cultures of chick embryo: role of culture conditions.

Immunoreactivity to calbindin D-28k, a vitamin D-dependent calcium-binding protein, is expressed by neuronal subpopulations of dorsal root ganglia (DRG) in the chick embryo. To determine whether the expression of this phenotypic characteristic is maintained in vitro and controlled by environmental factors, dissociated DRG cell cultures were performed under various conditions. Subpopulations of DRG cells cultured at embryonic day 10 displayed calbindin-immunoreactive cell bodies and neurites in both neuron-enriched or mixed DRG cell cultures. The number of calbindin-immunoreactive ganglion cells increased up to 7-10 days of culture independently of the changes occurring in the whole neuronal population. The presence of non-neuronal cells, which promotes the maturation of the sensory neurons, tended to reduce the percentage of calbindin-immunoreactive cell bodies. Addition of horse serum enhanced both the number of calbindin-positive neurons and the intensity of the immunostaining, but does not prevent the decline of the subpopulation of calbindin-immunoreactive neurons during the second week of culture; on the contrary, the addition of muscular extract to cultures at 10 days maintained the number of calbindin-expressing neurons. While calbindin-immunoreactive cell bodies grown in culture were small- or medium-sized, no correlation was found between cell size and immunostaining density. At the ultrastructural level, the calbindin immunoreaction was distributed throughout the neuroplasm. These results indicate that the expression of calbindin by sensory neurons grown in vitro may be modulated by horse serum-contained factors or interaction with non-neuronal cells. As distinct from horse serum, muscular extract is able to maintain the expression of calbindin by a subpopulation of DRG cells.

Vitaminas B y homocisteína en la insuficiencia renal crónica

Metabolic, biochemical, and hormonal changes occur in chronic renal failure usually associated with hyponutrition states. In predialysis patients, knowing the nutritional state about water-soluble vitamins such as thiamine, riboflavin, pyridoxine, cianocobalamine, and folic acid is becoming more and more important since some of the manifestations of chronic renal failure may be due to the deficiency of some of these water-soluble vitamins. The metabolic pathways in which most of these vitamins participate are interrelated and it is difficult to understand how the individual deficits of each vitamin affect renal pathology. This work aims at reviewing not only this issue but also the status of these water-soluble vitamins that different authors have found in groups of predialysis patients. On the other hand, the issue on the high prevalence of hyperhomocysteinemia in chronic renal failure as the main mortality risk factor due to cardiovascular pathologies as well as the implication of these vitamins in the metabolism of homocysteine, and consequently in plasma levels of this metabolite in predialysis patients is reviewed.

Genetics of leprosy reactions: an overview

Type-1 (T1R) and Type-2 (T2R) leprosy reactions (LR), which affect up to 50% of leprosy patients, are aggressive inflammatory episodes of sudden onset and highly variable incidence across populations. LR are often diagnosed concurrently with leprosy, but more frequently occur several months after treatment onset. It is not uncommon for leprosy patients to develop recurring reactional episodes; however, they rarely undergo both types of LR. Today, LR are the main cause of permanent disabilities associated with leprosy and represent a major challenge in the clinical management of leprosy patients. Although progress has been made in understanding the immunopathology of LR, the factors that cause a leprosy patient to suffer from LR are largely unknown. Given the impact that ethnic background has on the risk of developing LR, host genetic factors have long been suspected of contributing to LR. Indeed, polymorphisms in seven genes [Toll-like receptors (TLR)1, TLR2, nucleotide-binding oligomerisation domain containing 2, vitamin D receptor, natural resistance-associated macrophage protein 1, C4B and interleukin-6] have been found to be associated with one or more LR outcomes. The identification of host genetic markers with predictive value for LR would have a major impact on nerve damage control in leprosy. In this review, we present the recent advances achieved through genetic studies of LR.

Osteoprotegerin and bone mineral density in hemodiafiltration patients.

A newly identified cytokine, osteoprotegerin (OPG) appears to be involved in the regulation of bone remodeling. In vitro studies suggest that OPG, a soluble member of the TNF receptor family of proteins, inhibits osteoclastogenesis by interrupting the intercellular signaling between osteoblastic stromal cells and osteoclast progenitors. As patients with chronic renal failure (CRF) often have renal osteodystrophy (ROD), we investigated the role of osteoprotegerin (OPG) in ROD, and investigated whether there was any relationship between serum OPG, intact parathyroid (PTH) (iPTH), vitamin D, and trabecular bone. Serum OPG combined with iPTH might be a useful tool in the noninvasive diagnosis of ROD, at least in cases in which the range of PTH values compromises reliable diagnosis. Thirty-six patients on maintenance hemodiafiltration (HDF) and a control group of 36 age and sex matched healthy subjects with no known metabolic bone disease were studied. The following assays were made on serum: iPTH, osteocalcin (BGP), bone alkaline phosphatase, 25(OH)-cholecalciferol, calcium, phosphate, OPG, IGF-1, estradiol, and free testosterone. Serum Ca++, P, B-ALP, BGP, IGF-1, iPTH, and OPG levels were significantly higher in HDF patients than in controls, while DXA measurements and quantitative ultrasound (QUS) parameters were significantly lower. On grouping patients according to their mean OPG levels, we observed significantly lower serum IGF-1, vitamin D3 concentrations, and lumbar spine and hip bone mineral density in the high OPG groups. No correlation was found between OPG and bone turnover markers, whereas a negative correlation was found between serum OPG and IGF-1 levels (r=-0.64, p=0.032). Serum iPTH concentrations were positively correlated with bone alkaline phosphatase (B-ALP) (r=0.69, p=0.038) and BGP (r=0.92, p<0.001). The findings made suggest that an increase in OPG levels may be a compensatory response to elevated bone loss. The low bone mineral density (BMD) levels found in the high OPG group might have been due to the significant decrease in serum IGF-1 and vitamin D3 observed. In conclusion, the findings made in the present study demonstrate that increased OPG in hemodiafiltration patients is only partly due to decreased renal clearance. As it may partly reflect a compensatory response to increased bone loss, this parameter might be helpful in the identification of patients with a marked reduction in trabecular BMD.

Nutrient patterns and their food sources in an International Study Setting: report from the EPIC study.

BACKGROUND Compared to food patterns, nutrient patterns have been rarely used particularly at international level. We studied, in the context of a multi-center study with heterogeneous data, the methodological challenges regarding pattern analyses. METHODOLOGY/PRINCIPAL FINDINGS We identified nutrient patterns from food frequency questionnaires (FFQ) in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study and used 24-hour dietary recall (24-HDR) data to validate and describe the nutrient patterns and their related food sources. Associations between lifestyle factors and the nutrient patterns were also examined. Principal component analysis (PCA) was applied on 23 nutrients derived from country-specific FFQ combining data from all EPIC centers (N = 477,312). Harmonized 24-HDRs available for a representative sample of the EPIC populations (N = 34,436) provided accurate mean group estimates of nutrients and foods by quintiles of pattern scores, presented graphically. An overall PCA combining all data captured a good proportion of the variance explained in each EPIC center. Four nutrient patterns were identified explaining 67% of the total variance: Principle component (PC) 1 was characterized by a high contribution of nutrients from plant food sources and a low contribution of nutrients from animal food sources; PC2 by a high contribution of micro-nutrients and proteins; PC3 was characterized by polyunsaturated fatty acids and vitamin D; PC4 was characterized by calcium, proteins, riboflavin, and phosphorus. The nutrients with high loadings on a particular pattern as derived from country-specific FFQ also showed high deviations in their mean EPIC intakes by quintiles of pattern scores when estimated from 24-HDR. Center and energy intake explained most of the variability in pattern scores. CONCLUSION/SIGNIFICANCE The use of 24-HDR enabled internal validation and facilitated the interpretation of the nutrient patterns derived from FFQs in term of food sources. These outcomes open research opportunities and perspectives of using nutrient patterns in future studies particularly at international level.

Algoritmo para el diagnóstico precoz de la deficiencia de vitamina b12 en ancianos

BACKGROUND: The elderly population is particularly at risk for developing vitamin B12-deficiency. Serum cobalamin does not necessarily reflect a normal B12 status. The determination of methylmalonic acid is not available in all laboratories. Issues of sensitivity for holotranscobalamin and the low specificity of total homocysteine limit their utility. The aim of the present study is to establish a diagnostic algorithm by using a combination of these markers in place of a single measurement. METHODS: We compared the diagnostic efficiency of these markers for detection of vitamin B12 deficiency in a population (n = 218) of institutionalized elderly (median age 80 years). Biochemical, haematological and morphological data were used to categorize people with or without vitamin B12 deficiency. RESULTS: In receiver operating curves characteristics for detection on vitamin B12 deficiency using single measurements, serum folate has the greatest area under the curve (0.87) and homocysteine the lowest (0.67). The best specificity was observed for erythrocyte folate and methylmalonic acid (100% for both) but their sensitivity was very low (17% and 53%, respectively). The highest sensitivity was observed for homocysteine (81%) and serum folate (74%). When we combined these markers, starting with serum and erythrocyte folate, followed by holotranscobalamin and ending by methylmalonic acid measurements, the overall sensitivity and specificity of the algorithm were 100% and 90%, respectively. CONCLUSION: The proposed algorithm, which combines erythrocyte folate, serum folate, holotranscobalamin and methylmalonic acid, but eliminate B12 and tHcy measurements, is a useful alternative for vitamin B12 deficiency screening in an elderly institutionalized cohort.

Freedom Trial First-Year Extension: Results from 4 Years of Denosumab Exposure in Women with Postmenopausal Osteoporosis

Aims: To investigate the long-term efficacy and safety of denosumab (DMAb) for the treatment of postmenopausal women with osteoporosis in an open-label extension to the 3-year FREEDOM study.1Methods: All women who completed the FREEDOM study were eligible to enter a long-term open-label extension (up to 10 years). After providing informed consent, participants received 6-monthly subcutaneous injections of DMAb (60 mg). Here we report data from the first year of followup. For women randomized to DMAb in the FREEDOM study ('long-term group'), this represents up to 48 months of DMAb exposure (eight 6-monthly injections). For those randomized to placebo ('de novo group') the data are from up to 12 months of exposure (two injections). All participants continued to take calcium (1 g) and vitamin D (≥400 IU) supplements daily. Changes in bone mineral density (BMD) and bone turnover markers (BTM) are reported for subjects enrolled in the extension. No formal statistical testing was planned for this interim report. P-values are descriptive.Results: Overall, 4,550 eligible women (70.2%) who completed the FREEDOM study entered the open-label extension study (long-term, n=2,343; de novo, n=2,207). During the first year of the extension, lumbar spine (LS) BMD in the long-term group further increased by 2.0% (12.1% increase vs. FREEDOM baseline at 48 months), and total hip (TH) BMD further increased by 0.8% (6.5% increase at 48 months) (p<0.0001 for both BMD gains during year 4; Fig. 1). During the first year of the extension, LS and TH BMD increased by 5.4% and 3.0%, respectively in the de novo group (both p<0.0001). After DMAb initiation, serum C-telopeptide (CTX) in the de novo group decreased rapidly and similarly to the long-term group (Fig. 2). Reductions in BTMs continue to attenuate at the end of the dosing interval as previously reported. Adverse event (AE) rates were similar (70.4% of women in the longterm group and 67.9% in the de novo group). Serious Aes were also similar (9.8% and 11.2% of women, respectively). During year 4, osteoporotic nonvertebral fractures were reported in 31 women in the long-term group and 51 in the denovo group.Fig. 1. Percentage change in BMD with denosumab for4 years (long-term) or 1 year (de novo)Fig. 2. Percentage change in sCTX over timeConclusions: These interim results suggest that continuation of DMAb treatment through 48 months is associated with further significant increases in spine and hip BMD with sustained reduction of bone turnover. The de-novo treatment group results confirm the first year active treatment findings previously reported1.Acknowledgements: Amgen Inc. sponsored this study. Figure ©2010, American Society for Bone and Mineral Research, used by permission, all rights reserved. Disclosure of Interest: H. Bone Grant/Research Support from: Amgen, Eli Lilly, Merck, Nordic Bioscience, Novartis, Takeda Pharmaceuticals, Consultant/Speaker's bureau/ Advisory activities with: Amgen, Merck, Takeda Pharmaceuticals, Zelos, S. Papapoulos Consultant/Speaker's bureau/ Advisory activities with: Amgen, Merck, Novartis, Lilly, Procter and Gamble, GSK, M.-L. Brandi Grant/Research Support from: MSD, GSK, Nycomed, NPS, Amgen, J. Brown Grant/Research Support from: Abbott, Amgen, Bristol Myers Squibb, Eli Lilly, Pfizer, Roche, Consultant/ Speaker's bureau/Advisory activities with: Abbott, Amgen, Eli Lilly, Novartis, Merck, Warner Chilcott,, R. Chapurlat Grant/Research Support from: Servier, Sanofi-Aventis, Warner-Chilcott, Novartis, Merck, Consultant/Speaker's bureau/Advisory activities with: Servier, Novartis, Amgen, E. Czerwinski: None Declared, N. Daizadeh Employee of: Amgen Inc., Stock ownership or royalties of: Amgen Inc., A. Grauer Employee of: Amgen Inc., Stock ownership or royalties of: Amgen Inc., C. Haller Employee of: Amgen Inc., Stock ownership or royalties of: Amgen Inc., M.-A. Krieg: None Declared, C. Libanati Employee of: Amgen Inc., Stock ownership or royalties of: Amgen Inc., Z. Man Grant/Research Support from: Amgen, D. Mellström: None Declared, S. Radominski Grant/Research Support from: Amgen, Pfizer, Roche, BMS, J.-Y. Reginster Grant/Research Support from: Bristol Myers Squibb, Merck Sharp & Dohme, Rottapharm, Teva, Lilly, Novartis, Roche, GlaxoSmithKline, Amgen, Servier, Consultant/Speaker's bureau/ Advisory activities with: Servier, Novartis, Negma, Lilly,Wyeth, Amgen, GlaxoSmithKline, Roche, Merckle, Nycomed, NPS, Theramex, UCB, Merck, Sharpe & Dohme, Rottapharm, IBSA, Genvrier, Teijin, Teva, Ebewee Pharma, Zodiac, Analis, Theramex, Novo-Nordisk, H. Resch: None Declared, J. A. Román Grant/Research Support from: Roche, Pharma, C. Roux Grant/Research Support from: Amgen, MSD, Novartis, Servier, Roche, Consultant/ Speaker's bureau/Advisory activities with: Amgen, MSD, Novartis, Servier, Roche, S. Cummings Grant/ Research Support from: Amgen, Lilly, Consultant/Speaker's bureau/Advisory activities with: Amgen, Lilly, Novartis, Merck

Fracture risk and zoledronic acid therapy in men with osteoporosis.

BACKGROUND: Fractures in men are a major health issue, and data on the antifracture efficacy of therapies for osteoporosis in men are limited. We studied the effect of zoledronic acid on fracture risk among men with osteoporosis. METHODS: In this multicenter, double-blind, placebo-controlled trial, we randomly assigned 1199 men with primary or hypogonadism-associated osteoporosis who were 50 to 85 years of age to receive an intravenous infusion of zoledronic acid (5 mg) or placebo at baseline and at 12 months. Participants received daily calcium and vitamin D supplementation. The primary end point was the proportion of participants with one or more new morphometric vertebral fractures over a period of 24 months. RESULTS: The rate of any new morphometric vertebral fracture was 1.6% in the zoledronic acid group and 4.9% in the placebo group over the 24-month period, representing a 67% risk reduction with zoledronic acid (relative risk, 0.33; 95% confidence interval, 0.16 to 0.70; P=0.002). As compared with men who received placebo, men who received zoledronic acid had fewer moderate-to-severe vertebral fractures (P=0.03) and less height loss (P=0.002). Fewer participants who received zoledronic acid had clinical vertebral or nonvertebral fractures, although this difference did not reach significance because of the small number of fractures. Bone mineral density was higher and bone-turnover markers were lower in the men who received zoledronic acid (P<0.05 for both comparisons). Results were similar in men with low serum levels of total testosterone. The zoledronic acid and placebo groups did not differ significantly with respect to the incidence of death (2.6% and 2.9%, respectively) or serious adverse events (25.3% and 25.2%). CONCLUSIONS: Zoledronic acid treatment was associated with a significantly reduced risk of vertebral fracture among men with osteoporosis. (Funded by Novartis Pharma; ClinicalTrials.gov number, NCT00439647.).

Genetics of calcium homeostasis in humans: continuum between monogenic diseases and continuous phenotypes

Extracellular calcium participates in several key physiological functions, such as control of blood coagulation, bone calcification or muscle contraction. Calcium homeostasis in humans is regulated in part by genetic factors, as illustrated by rare monogenic diseases characterized by hypo or hypercalcaemia. Both serum calcium and urinary calcium excretion are heritable continuous traits in humans. Serum calcium levels are tightly regulated by two main hormonal systems, i.e. parathyroid hormone and vitamin D, which are themselves also influenced by genetic factors. Recent technological advances in molecular biology allow for the screening of the human genome at an unprecedented level of detail and using hypothesis-free approaches, such as genome-wide association studies (GWAS). GWAS identified novel loci for calcium-related phenotypes (i.e. serum calcium and 25-OH vitamin D) that shed new light on the biology of calcium in humans. The substantial overlap (i.e. CYP24A1, CASR, GATA3; CYP2R1) between genes involved in rare monogenic diseases and genes located within loci identified in GWAS suggests a genetic and phenotypic continuum between monogenic diseases of calcium homeostasis and slight disturbances of calcium homeostasis in the general population. Future studies using whole-exome and whole-genome sequencing will further advance our understanding of the genetic architecture of calcium homeostasis in humans. These findings will likely provide new insight into the complex mechanisms involved in calcium homeostasis and hopefully lead to novel preventive and therapeutic approaches. Keyword: calcium, monogenic, genome-wide association studies, genetics.

Gain-of-function haplotype in the epithelial calcium channel TRPV6 is a risk factor for renal calcium stone formation.

The rate-limiting step of dietary calcium absorption in the intestine requires the brush border calcium entry channel TRPV6. The TRPV6 gene was completely sequenced in 170 renal calcium stone patients. The frequency of an ancestral TRPV6 haplotype consisting of three non-synonymous polymorphisms (C157R, M378V, M681T) was significantly higher (P = 0.039) in calcium stone formers (8.4%; derived = 502, ancestral = 46) compared to non-stone-forming individuals (5.4%; derived = 645, ancestral = 37). Mineral metabolism was investigated on four different calcium regimens: (i) free-choice diet, (ii) low calcium diet, (iii) fasting and (iv) after a 1 g oral calcium load. When patients homozygous for the derived haplotype were compared with heterozygous patients, no differences were found with respect to the plasma concentrations of 1,25-vitamin D, PTH and calcium, and the urinary excretion of calcium. In one stone-forming patient, the ancestral haplotype was found to be homozygous. This patient had absorptive hypercalciuria. We therefore expressed the ancestral protein (157R+378V+681T) in Xenopus oocytes and found a significantly enhanced calcium permeability when tested by a (45)Ca(2+) uptake assay (7.11 +/- 1.93 versus 3.61 +/- 1.01 pmol/min/oocyte for ancestral versus derived haplotype, P < 0.01). These results suggest that the ancestral gain-of-function haplotype in TRPV6 plays a role in calcium stone formation in certain forms of absorptive hypercalciuria.