Osteoporosis. Pathogenesis, diagnosis, and treatment in older adults

Sex and aging signatures of proteomics in human cerebrospinal fluid identify distinct clusters linked to neurodegeneration

Sex and age are major risk factors for chronic diseases. Recent studies examining age-related molecular changes in plasma provided insights into age-related disease biology. Cerebrospinal fluid (CSF) proteomics can provide additional insights into brain aging and neurodegeneration. By comprehensively examining 7,006 aptamers targeting 6,139 proteins in CSF obtained from 660 healthy individuals aged from 43 to 91 years old, we subsequently identified significant sex and aging effects on 5,097 aptamers in CSF. Many of these effects on CSF proteins had different magnitude or even opposite direction as those on plasma proteins, indicating distinctive CSF-specific signatures. Network analysis of these CSF proteins revealed not only modules associated with healthy aging but also modules showing sex differences. Through subsequent analyses, several modules were highlighted for their proteins implicated in specific diseases. Module 2 and 6 were enriched for many aging diseases including those in the circulatory systems, immune mechanisms, and neurodegeneration. Together, our findings fill a gap of current aging research and provide mechanistic understanding of proteomic changes in CSF during a healthy lifespan and insights for brain aging and diseases.

Matrix Metalloproteinases in Relation to Bone Mineral Density: A Two-Sample Mendelian Randomization Study

Background: We aimed at investigating causal associations between matrix metalloproteinases (MMPs) and bone mineral density (BMD) by the Mendelian randomization (MR) analysis. Methods: From genome-wide association studies of European ancestry, we selected instrumental variables for MMP-1, MMP-3, MMP-7, MMP-8, MMP-10, and MMP-12. Accordingly, we retrieved summary statistics of three site-specific BMD, namely, forearm, femoral neck, and lumbar spine. We conducted an inverse variance weighted MR as the primary method to compute overall effects from multiple instruments, while additional MR approaches and sensitivity analyses were implemented. Bonferroni-adjusted significance threshold was set at p < 0.05/18 = 0.003. Results: Totally, there was no evidence for causal effects of genetically-predicted levels of MMPs on BMD measurement at three common sites. MR results indicated that there were no causal associations of circulating MMPs with forearm BMD (all p ≥ 0.023) by the inverse variance weighted method. Similarly, there were no causal effects of MMPs on femoral neck BMD (all p ≥ 0.120) and MR results did not support causal relationships between MMPs and lumbar spine BMD (all p ≥ 0.017). Multiple sensitivity analyses suggested the robustness of MR results, which were less likely to be biased by unbalanced pleiotropy or evident heterogeneity. Conclusion: We found no evidence for the causal relationship between MMPs and BMD in the European population.

A cross-sectional study of characteristics of bicyclist upper and lower extremity injuries in bicycle-vehicle crashes in Ohio, United States, 2013-2017

Background

Extremity injury is one of the most common injury types for bicyclists. Extremity injury can lead to long-term disability and contribute to adverse health-related quality of life and prolonged absence from work.

Objectives

The objectives of our study were to identify crash factors associated with bicyclist upper and lower extremity injury and characterize type of extremity injury by bicyclist age category.

Methods

We linked the 2013–2017 Ohio police accident report and hospital databases. The logistic regression model was used to model the odds of sustaining upper or lower extremity injury among bicyclists involved in bicycle-vehicle crashes. Bicyclist upper and lower extremity injury were further described by the detailed injured body regions (e.g., forearm and elbow or lower leg) and the nature of injury (e.g., superficial or fracture).

Results

Bicyclists 65 years or older had higher odds (odds ratio [OR] = 1.46, 95% confidence interval [CI]: 1.03–2.08) of sustaining upper extremity injury, bicyclists aged 3–14 years (OR = 1.34, 95% CI: 1.09–1.66) and 15–24 years (OR = 1.24, 95% CI: 1.03–1.49) had higher odds of sustaining lower extremity injury, compared to bicyclists 25–44 years old. In addition, colder weather, bicyclist sex, and intersection-related crashes were associated with bicyclists’ odds of sustaining upper or lower extremity injury. Compared to individuals under 65 years old, bicyclists 65 years or older had a higher percentage of injury to the wrist, hand and finger, or knee. Bicyclists aged 65 years or older also had a higher percentage of fractures.

Conclusions

Our study has identified important factors that were associated with bicyclists’ odds of sustaining an extremity injury. Based on these findings, targeted educational efforts and interventions can be implemented to prevent bicyclists from these injuries.

Changes to gait speed when romantic partners walk together: Effect of age and obstructed pathway

BACKGROUND

Walking at a brisk pace is widely recommended to promote health. When partners walk together, walking activity is increased and maintained due to enhanced social support and accountability, but at least one person must adjust their gait speed. Decreased gait speed could compromise health benefits, which may be especially relevant for the aging population.

RESEARCH QUESTION

Do adults change gait speed when walking with their romantic partner, relative to walking alone, and is the change in speed affected by age or pathway conditions?

METHODS

Participants were 141 individuals from 72 romantic couples; age range 25-79 years. The three couple conditions were walking alone, walking with their partner, and walking while holding hands with their partner. The two pathway conditions were clear pathway and pathway with obstacles. Gait speed was modeled as a function of the couple conditions, pathway conditions, and covariates (gender, age, relationship duration, and physical activity) using mixed-effects (3-level) regression.

RESULTS

In both pathway conditions, both partners reduced speed when walking together (p < 0.001), and reduced speed further while holding hands (p < 0.001), when compared to walking alone. These effects were unchanged when covariates were included in the model. Further, speed was slower on the obstructed pathway for all participants, but the magnitude of slowing was greater with increasing age (p < 0.001) and in females (p=0.03).

SIGNIFICANCE

Across the adult lifespan, when walking together, both partners decreased gait speed by a clinically meaningful amount (≥0.05 m/s). While walking with a partner may increase walking activity due to social support, reduced speed when walking together may unintentionally reduce health benefits and gait quality in both partners. Future research should identify how health is impacted by the trade-off between increased walking activity and reduced gait speed when romantic partners walk together.

A Statistical Approach Regarding the Diagnosis of Osteoporosis and Osteopenia From DXA: Are We Underdiagnosing Osteoporosis?

Osteoporosis and osteopenia are diagnosed most commonly by evaluating the lowest T‐score of BMD measurements, typically taken at three sites: the L1‐L4 lumbar spine, femoral neck, and total hip. This study aimed to evaluate the effect of using all three BMD measurements and multivariate statistical theory to evaluate how the diagnoses of osteoporosis and osteopenia change in simulation studies and in real data. First, it was found that the T‐scores from these three BMD measurements rarely give concordant diagnoses using the same World Health Organization (WHO) and International Society for Clinical Densitometry (ISCD) guidelines, so that the diagnosis strongly depends on the BMD sites measured. Next, strong correlations were found between the BMD measurements at different sites within the same person, which resulted in increased congruence/concordance between the diagnoses obtained from the BMD T‐scores. Multivariate statistical theory was used to show that the joint distribution of the BMD T‐scores at different sites follows a multivariate t distribution and found that the marginal distribution of any BMD T‐score follows a univariate t distribution. Confidence ellipsoids were derived that are equivalent to the univariate WHO/ISCD thresholds for osteoporosis (T‐score ≤−2.5) and osteopenia (−2.5 < T‐score <−1). The study found that more patients are diagnosed with osteoporosis using the multivariate version of the WHO/ISCD guidelines rather than the current WHO/ISCD guidelines in both real data and simulation studies. Diagnoses of osteoporosis using the statistics derived method were also associated with higher FRAX (fracture risk assessment tool) probabilities of major osteoporotic (p = 0.001) and hip fractures (p = 2.2 × 10⁻⁶). In conclusion, this study shows that considering all three BMD T‐scores is potentially more informative than using the single lowest BMD T‐score. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Characterization and Identification of Isoflavonoids in the Roots of Millettia speciosa Champ. by UPLC-Q-TOF-MS/MS

Introduction:

The root of Millettia speciosa Champ. (Leguminosae) is one of the wellknown traditional Chinese medicines abundant in phenolic compounds and plays important roles in the treatment of pain or numbness of the joints, blood deficiency sallow, chronic bronchitis and chronic hepatitis.

Objective:

An ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) based chemical profiling approach was established for the separation and characterization of isoflavonoids in the roots of Millettia speciosa Champ.

Methods:

The roots of Millettia speciosa Champ. were prepared by ethanol extraction followed by further extraction with chloroform. The extracts were analyzed by UPLC-Q-TOF-MS in positive and negative electrospray ion modes at different Collision Energy (CE) values.

Results:

A total of 48 components were simultaneously detected, of which 38 components, including 21 isoflavones, 4 phenolic acids, 4 isoflavanones, 2 phenolic aldehydes, 2 flavanones, 1 aliphatic acid, 1 chalcone, 1 flavonol, 1 isoflavane and 1 pterocarpan were unambiguously identified or tentatively assigned based on the retention time, UV spectra, characteristic molecular ions, MS/MS fragmentation data and reference standards. The isomers of isoflavonoids were distinguished using accurate mass, the diagnostic fragmentations of C-ring and UV spectra. The major diagnostic fragment ions of isoflavonoids were observed and the corresponding fragmentation pathways were proposed.

Conclusion:

This investigation provides important analysis data for further quality control, pharmacological and toxicological research on Millettia speciosa Champ.

Lactose Intolerance and Bone Health: The Challenge of Ensuring Adequate Calcium Intake

Calcium is an important nutrient with impact upon many biological systems, most notably bone. Ensuring adequate calcium intake throughout the lifespan is essential to building and maintaining bone. Lactose intolerance may predispose individuals to low calcium intake as the number of lactose-free, calcium-rich food sources is limited. In this review, we summarize data from human and animal studies on the influence of lactose and lactase deficiency on calcium absorption and bone health. Based on the available evidence, neither dietary lactose nor lactase deficiency have a significant impact on calcium absorption in adult humans. However, lactose intolerance may lead to reduced bone density and fragility fractures when accompanied by decreased intake or avoidance of dairy. Recently published human trials and meta-analyses suggest a weak but significant association between dairy consumption and bone health, particularly in children. Given the availability of simple dietary approaches to building lactose tolerance and the nutritional deficiencies associated with dairy avoidance, multiple public health organizations recommend that all individuals—including those that are lactose intolerant—consume three servings of dairy per day to ensure adequate nutrient intakes and optimal bone health.

Lipid profile and plasma atherogenic index in postmenopausal osteoporosis

OBJECTIVE

The goal of this study was to investigate the relationship between the lipid profile, plasma atherogenic index (PAI), and osteoporosis in postmenopausal women.

METHODS

The data of age, duration of menopause, height, weight, lipid profile, bone mineral density (BMD) value, and history of oral contraceptive use of 407 postmenopausal women who had not been menstruating for at least 12 months, were between the ages 45 and 80, and presented at the obstetrics and gynecology polyclinic of Kartal Dr. Lutfi Kirdar Tr aining and Research Hospital were reviewed. The patients were divided into 2 groups according to the presence of osteoporosis, and the data compared. The level of significance was accepted as p<0.05.

RESULTS

A total of 142 postmenopausal patients with osteoporosis were included in the study. The mean age was 61.7±6.9 years. In the control group, there were 263 postmenopausal women without osteoporosis, with a mean age of 58.3±4.5 years. There was no statistically significant difference with respect to triglyceride level; however, in the osteoporosis group, the level of total cholesterol and low-density lipoprotein (LDL) were lower, and the level of high-density lipoprotein (HDL) was higher (p=0.762, p=0.002, p=0.01, p<0.001, respectively).

CONCLUSION

A high level of HDL, and low LDL and PAI values, which are important for the prevention of cardiovascular disease, were found to be negative factors for BMD.

The effects of SOST on implant osseointegration in ovariectomy osteoporotic mice

OBJECTIVE

Osteoporosis is a risk factor for implant fixation failure. The inhibition of sclerostin effectively improves bone formation and bone remodeling. Therefore, this study investigated whether SOST deficiency enhances the osseointegration of implants in a mouse model of osteoporosis induced by ovariectomy (OVX).

DESIGN

Osteoporosis was induced in female C57BL/6 and SOST deficient mice by OVX. Titanium implants were placed in the bilateral distal aspects of the femurs. Implants underwent sandblasting and acid-etching after which the structure, surface roughness and chemical components were investigated using scanning electron microscopy (SEM) and energy spectrum analyses. Undecalcified slices, μ-CT, histology analyses and mechanical tests were used to evaluate the osseointegration of implants. The results were compared using one-way ANOVA between four groups.

RESULTS

Sandblasting and acid-etching increased the roughness of the implants. OVX surgery reduced bone formation around the implants in both WT and SOST^-/- mice. However, implant osseointegration was significantly improved in the SOST^-/- OVX mice compared to the WT OVX mice.

CONCLUSIONS

Inhibition of the SOST gene improved implant fixation in the OVX osteoporotic mice, which suggests a strategy for enhancing implant osseointegration in clinical patients with osteoporosis.

Effects of Antipsychotics on Bone Mineral Density in Patients with Schizophrenia: Gender Differences

Low bone mineral density (BMD) and osteoporosis are common in patients with schizophrenia and detrimental to illness prognosis and life quality. Although the pathogenesis is not fully clear, series of studies have revealed factors related to low BMD such as life style, psychotic symptoms, medication use and the activity of bone absorption markers. It has been known that antipsychotic-induced hyperprolactinemia plays a critical role on decreased BMD. However, it remains uncertain whether the risk factors differ between men and women. According to the effect on prolactin, antipsychotics can be classified into two groups: prolactin-sparing (PS) and prolactin-raising (PR). Our previous study has demonstrated that clozapine which is among the PS antipsychotics is beneficial for BMD when compared with PR antipsychotics in women with chronic schizophrenia. We have also found that risks factors associated with low BMD are different between men and women, suggesting that gender-specific risk factors should be considered for intervention of bone loss in patients with schizophrenia. This article reviews the effects of antipsychotics use on BMD with particular discussion for the differences on gender and age, which implicate the alterations of sex and other related hormones. In addition, currently reported protective and risk factors, as well as the effects of medication use on BMD including the combination of antipsychotics and other psychotropic agents and other potential medications are also reviewed.

Calcium and bone health--goodbye, calcium supplements?

This review assesses (1) the potential role of calcium supplements in the prevention and treatment of osteoporosis and osteoporotic fractures, and (2) the safety of calcium supplements with respect to cardiovascular health as well. With regard to (1), a total calcium intake of < 800 mg/day is associated with increased loss of bone mineral density in peri- and postmenopausal women with an increase in fracture risk. Hereby, the effect of calcium supplements on fracture prevention is dependent primary on baseline calcium intake. The strongest protective effect has been reported in individuals with a calcium intake < 700 mg/day and in high-risk groups. A calcium intake of about 1000-1200 mg/day seems to be sufficient for general fracture prevention. With regard to (2), an analysis of the data based on the Hill criteria does not demonstrate convincing evidence that calcium supplements increase cardiovascular risk. In the long term, total calcium intake of 2500 mg/day (from food and supplements) continues to be classified as safe. This value should not be exceeded for an extended period of time.

Prevalence of fracture and osteoporosis risk factors in American Indian and Alaska Native people

OBJECTIVE

Little is known about prevalence of osteoporosis risk factors among American Indians and Alaska Natives (AIAN).

METHODS

We included AIAN people (n=8,039) enrolled in the Education and Research Towards Health (EARTH) Study. Prevalence ratios were used to determine cross-sectional associations of risk factors with self-reported bone fractures.

RESULTS

There is a high prevalence of multiple risk factors for osteoporosis in AIAN, although the factors that are associated with past fracture vary by gender and geographical area. In general, women who reported a fracture reported more risk behaviors, more than two medical conditions, and low physical activity. Men with higher BMI were less likely to report a fracture. Smoking history was associated with fracture for both genders, though not significantly in all sub-groups.

CONCLUSION

We prevent a high prevalence of risk factors for osteoporosis for AIAN. Future research for osteoporosis risk reduction and prevention in AIAN people is indicated.

Vitaminas B12, B6, B9 e homocisteína e sua relação com a massa óssea em idosos

O número de idosos nos últimos anos tem apresentado incremento em todo o mundo, o que acaba gerando inúmeras preocupações com a saúde dessa população, já que nessa fase da vida as alterações fisiológicas os tornam mais propensos a doenças, principalmente as crônicas não-transmissíveis. A osteoporose, uma doença osteometabólica frequente nos idosos, torna-se alvo de importantes estudos, uma vez que suas consequências afetam tanto a saúde física quanto a psicossocial. Contudo, são diversos os fatores que predispõem à osteoporose, entre os quais a deficiência de vitamina B12, vitamina B9 (folato) e vitamina B6 (piridoxina). A carência dessas vitaminas eleva os níveis de homocisteína, que age interferindo nas ligações cruzadas do colágeno, resultando em diminuição da resistência óssea e, consequentemente, na osteoporose e fraturas ósseas tanto em homens quanto em mulheres. Nesse contexto, este artigo tem como objetivo realizar uma revisão de literatura nas bases de dados LILACS e PubMed, sobre a relação dos níveis séricos de vitamina B12, folato, vitamina B6 e homocisteína com a diminuição da massa óssea em idosos.

Myosin heavy chain isoform expression in the Vastus Lateralis muscle of aging African green vervet monkeys

Non-human primates (NHP) represent an emerging animal model for the study of physical function, and provide opportunities for exploration of relationships of muscle biomolecular changes with age. One such primate model, the African green vervet monkey, has been used extensively in biomedical research but little is known regarding skeletal muscle composition, expression of myosin heavy chain (MHC) isoforms, and changes with age. In the present study we examined the effects of age on vastus lateralis (VL) muscle fiber-type composition, fiber cross-sectional area (CSA), and MHC isoforms expressed in 4 young and 4 older adult vervet monkeys. Proteomics analysis, using a human and nonhuman primate protein database, showed five MHC isoforms (I, IIA, IIX, IIB, and IIB') expressed in female vervet VL muscle, which matched the human MHC isoforms. Fast type II fibers predominated and no pure type IIB or IIB' containing fibers were detected. Hybrid fibers containing IIB/IIB' MHC decreased in the old vervets. The CSA of both type I and type II fibers was significantly smaller in older vervet while type IIA fibers showed the most severity of atrophy. The decrease of fast MHC and atrophy of muscle fiber with aging recapitulate observations in human VL muscle. These findings, along with its homology of MHC between the vervet and human suggested that the vervet monkey may be a suitable preclinical model for understanding the cellular and molecular basis of sarcopenia and for developing new interventions to ameliorate the impact of disorders that affect skeletal muscle structure and function.

Mechanosensing by the primary cilium: deletion of Kif3A reduces bone formation due to loading

Primary cilia, solitary microtubule-based structures that grow from the centriole and extend into the extracellular space, have increasingly been implicated as sensors of a variety of biochemical and biophysical signals. Mutations in primary cilium-related genes have been linked to a number of rare developmental disorders as well as dysregulation of cell proliferation. We propose that primary cilia are also important in mechanically regulated bone formation in adults and that their malfunction could play a role in complex multi-factorial bone diseases, such as osteoporosis. In this study, we generated mice with an osteoblast- and osteocyte-specific knockout of Kif3a, a subunit of the kinesin II intraflagellar transport (IFT) protein; IFT is required for primary cilia formation, maintenance, and function. These Colα1(I) 2.3-Cre;Kif3a(fl/fl) mice exhibited no obvious morphological skeletal abnormalities. Skeletally mature Colα1(I) 2.3-Cre;Kif3a(fl/fl) and control mice were exposed to 3 consecutive days of cyclic axial ulna loading, which resulted in a significant increase in bone formation in both the conditional knockouts and controls. However, Colα1(I) 2.3-Cre;Kif3a(fl/fl) mice did exhibit decreased formation of new bone in response to mechanical ulnar loading compared to control mice. These results suggest that primary cilia act as cellular mechanosensors in bone and that their function may be critical for the regulation of bone physiology due to mechanical loading in adults.

Bone density in chronic schizophrenia with long-term antipsychotic treatment: preliminary study

OBJECTIVE

Decreased bone mineral density has been found in the chronic schizophrenic patients who have been given a long-term administration of antipsychotics. Hyperprolactinemia from the antipsychotics and the negative symptom of schizophrenia were considered as the causes for this finding. In this study, the effect of hyperprolactinemia and the negative symptom of schizophrenia on bone mineral density was investigated on male schizophrenic patients.

METHODS

The cross-sectional study was carried out with the subjects of 45 male schizophrenic patients who have undertaken the monotherapy with risperidone, olanzapine and clozapine for at least one year. The demographic factors, clinical symtoms, bone mineral density and hematological test were examined for all the subjects.

RESULTS

No significant relationship was found between hyperprolactinemia and the decreased bone mineral density in the subjects. The negative schizophrenia symptom of the subjects showed a significant effect on the decreased bone mineral density.

CONCLUSION

The decreased bone mineral density finding in the male schizophrenic patients may be caused by the negative schizophrenia symptom rather than the hyperprolactinemia due to the antipsychotics. Additional studies are further required regarding other factors that may affect the decreased bone mineral density such as activity, calcium intake and exposure to sunlight.

The role of cigarette smoking and statins in the development of postmenopausal osteoporosis: a pilot study utilizing the Marshfield Clinic Personalized Medicine Cohort

SUMMARY

A cohort of postmenopausal osteoporotic females and controls with normal bone mineral density, the interleukin 6 (IL6) -634G > C (rs1800796) C allele of the promoter region showed association with osteoporosis. The lipoprotein receptor-related protein 5 (LRP5) gene showed association between C135242T C/T alleles and osteoporosis only in smokers, suggesting a role for environmental interaction.

INTRODUCTION

A nested case-control study within a population-based cohort was undertaken to assess the relative impact of cigarette smoking, statin use, genetic polymorphisms, and one-way interaction of these factors on development of osteoporosis in postmenopausal women.

METHODS

Genotyping of 14 single-nucleotide polymorphisms (SNPs) corresponding to vitamin D receptor gene, estrogen receptor 1, collagen type 1 alpha 1, IL6, transcription growth factor beta, apolipoprotein E, and LRP5 genes was performed in cases (n = 309) with osteoporosis and controls (n = 293) with normal bone mineral density drawn from a homogeneous Caucasian population. SNPs were chosen based on known functional consequences or prior evidence for association and genotyped using matrix-assisted laser desorption ionization time-of-flight technology.

RESULTS

Cases differed from controls relative to body mass index, age, and smoking but not statin use. After adjusting for age, the IL6 -634G > C (rs1800796) allele showed association with osteoporosis (odds ratio (OR) for CC + CG = 2.51, p = 0.0047)), independent of statin use or smoking status. On stratification for smoking, association with LRP5 C135242T (rs545382) and osteoporosis emerged (OR 2.8 in smokers for CT alleles, p = 0.03)), suggestive of potential environmental interaction.

CONCLUSION

Evidence suggested a role for genetic variation in IL6 and LRP5 in conferring risk for osteoporosis in Caucasian women, with the latter manifest only in smokers.

Phytoestrogens from Aspalathus linearis

From the leaves of Aspalathus linearis, 24 known compounds and a new one, aspalalinin (25), were isolated. The structures of the compounds were determined mainly based on spectral evidence. The absolute configuration of aspalalinin was presented on the basis of X-ray analysis. Each isolate was assessed for its estrogenic activity by an estrogen ELISA assay. Compounds 12, 15, and 24 showed the estrogenic activity.

Serum lipid profile: its relationship with osteoporotic vertebrae fractures and bone mineral density in Turkish postmenopausal women

The effect of the serum lipid levels on vertebral fractures and bone mineral density is not clear. A total of 107 postmenopausal women aged 45-79 examined by lumbar spine, hip and radius bone mineral density (BMD) measurements, lateral dorsal and lumbar spine radiographies, routine blood tests and serum lipids [total cholesterol (TC), triglyceride (TG), HDL-C, LDL-C, VLDL-C]. Demographic and lifestyle characteristics were collected. Eighty-nine radiographies with good technical properties were scored by the Kleerekoper method. Patients with vertebrae fractures had lower levels of TC, TG, LDL-C than the patients without vertebrae fractures. Total cholesterol level was the most prominent factor affecting the vertebral fracture existence. An increase of 1 mg/dl total cholesterol decreases the risk of vertebrae fracture by 2.2%. The existence of osteoporosis due to T score was not influencing the lipid values. TC and LDL-C were weakly associated with BMD at the forearm UD region after the adjustment for the possible confounders. This study shows that the serum lipids have impact on vertebrae fracture existence rather than BMD alterations.

Phytoestrogens induce differential estrogen receptor beta-mediated responses in transfected MG-63 cells

Phytoestrogens may function as partial agonists or antagonists of estrogen in many tissues including bone. Five phytoestrogens, belonging to the isoflavones and the flavonoids groups, were assayed in the human MG-63 osteoblastic cell line for their ability to stimulate transcriptional activity of an estrogen-response element (ERE)-luciferase reporter gene via the estrogen receptor beta (ERbeta). Although MG-63 cells were shown to express endogenous estrogen receptors, estradiol (E2) did not affect transcriptional activity of an ERE reporter in these cells. However, E2 did activate the ERE-reporter significantly in MG-63 cells where ERbeta was overexpressed. The isoflavones, genistein and daidzein, caused a dose-dependent increase in the ERE-reporter activity in MG-63 cells overexpressing ERbeta. Among the flavonoids, kaempferol activated ERE-reporter activity, whereas puerarin inhibited ERE-reporter transcription in cells overexpressing ERbeta. Quercetin had no effect on ERE-reporter activity over a concentration range of 10(-10)-10(-6) mol/l. The ERE-reporter activity induced by daidzein, genistein, and kaempferol was blocked by both ICI 182780 and 4-hydroxytamoxifen and partly blocked by puerarin. Our results demonstrated that different phytoestrogens exhibited differential transcription activity of an ERE-reporter via ERbeta-mediated mechanisms in MG-63 cells.

Correlates of bone mineral density among postmenopausal women of African Caribbean ancestry: Tobago women's health study

Population dynamics predict a drastic growth in the number of older minority women, and resultant increases in the number of fractures. Low bone mineral density (BMD) is an important risk factor for fracture. Many studies have identified the lifestyle and health-related factors that correlate with BMD in Whites. Few studies have focused on non-Whites. The objective of the current analyses is to examine the lifestyle, anthropometric and health-related factors that are correlated with BMD in a population based cohort of Caribbean women of West African ancestry. We enrolled 340 postmenopausal women residing on the Caribbean Island of Tobago. Participants completed a questionnaire and had anthropometric measures taken. Hip BMD was measured by DXA. We estimated volumetric BMD by calculating bone mineral apparent density (BMAD). BMD was >10% and >25% higher across all age groups in Tobagonian women compared to US non-Hispanic Black and White women, respectively. In multiple linear regression models, 35-36% of the variability in femoral neck and total hip BMD respectively was predicted. Each 16-kg (one standard deviation (SD)) increase in weight was associated with 5% higher BMD; and weight explained over 10% of the variability of BMD. Each 8-year (1 SD) increase in age was associated with 5% lower BMD. Current use of both thiazide diuretics and oral hypoglycemic medication were associated with 4-5% higher BMD. For femoral neck BMAD, 26% of the variability was explained by a multiple linear regression model. Current statin use was associated with 5% higher BMAD and a history of breast feeding or coronary heart disease was associated with 1-1.5% of higher BMAD. In conclusion, African Caribbean women have the highest BMD on a population level reported to date for women. This may reflect low European admixture. Correlates of BMD among Caribbean women of West African ancestry were similar to those reported for U.S. Black and White women.

Comprehensive fall prevention programs across settings: a review of the literature

The prevention and management of falls across health care and community settings continues to be one of the greatest challenges in geriatric nursing. This article reviews the literature on fall prevention and management and provides information on national programs and resources, as well as public policy related to falls in the elderly.

Trends in pathological vertebral fractures in the United States: 1993 to 2004

OBJECT

Pathological vertebral fractures (PVFs) are an increasingly important cause of disability and have many clinical and economic implications. The authors examined trends in epidemiology and surgical management of pathological vertebral fractures in the US between 1993 and 2004.

METHODS

The Nationwide Inpatient Sample database was used to analyze data collected from 1993 through 2004 to determine general trends in PVFs. Patients with PVFs were identified using the appropriate International Classification of Diseases, 9th Revision (ICD-9) diagnostic code (ICD-9 733.13). Trends in vertebral augmentation procedures and spinal fusions as well as comparison with incidences of other major pathological fractures, such as hip and upper limb, were also examined.

RESULTS

In 2004, there were more than 55,000 inpatient admissions for PVFs. The majority of patients admitted were women (78%) in the 65 to 84 year-age group (60%). Medicare accounted for greater than 80% of insurance, and nearly 50% of all patients were admitted from the emergency department. The mean duration of hospitalization has continued to decrease, from 8.1 days in 1993 to 5.4 days in 2004. The mortality rate has remained relatively constant at approximately 1.5%. The discharge disposition has continued to change with an increasing number of patients being discharged to other institutions such as nursing homes and rehabilitation facilities. There was a staggering increase in the number of vertebral augmentation procedures performed between 1993 and 2004. The "national bill" for inpatient hospitalizations for PVFs totaled $1.3 billion in 2004.

CONCLUSIONS

With the continued aging of the population, PVFs represent an important cause of disability and a significant source of healthcare resource utilization.

Medical Screening for Red Flags in the Diagnosis and Management of Musculoskeletal Spine Pain

When a patient presents with pain in the different regions of the spine, the clinician executes a region-appropriate basic examination that includes appropriate historical cues and specific physical examination tests that can be used to identify red flags. The clinical tests include a specific examination of the sensory and motor systems. Test outcomes are best interpreted in context with the entire examination profile, where the sensitivity and specificity of these tests can influence their utility in uncovering red flags. These red flags can be categorized based on the nature and severity or the specific elements of the patient's presentation. Many general red flags can be observed in any region of the spine, while specific red flags must be categorized and discussed for each spinal region. This categorization can guide the clinician in the direction of management, whether that management is aimed at redirecting the patient's care to another specialist, reconsidering the presentation and observing for clusters of findings that may suggest red flags, or managing the patient within the clinician's specialty in context with the severity of the patient's presentation.

Risk for Osteoporosis and Antiresorptive Therapies in Patients with Crohn's Disease

Background:

The risk of osteoporosis is greater in patients with inflammatory bowel disease (IBD) because of several related risk factors such as the prolonged use of corticosteroids, the malabsorption of calcium and vitamin D following small-bowel disease or small-bowel resections, and the inflammatory process resulting from the illness. A reduction in bone mineral density (BMD) has been reported in 30–75% of patients with IBD (Crohn's disease or ulcerative colitis). An evaluation of the risk factors of osteoporosis should be performed to identify those in need of antiresorptive drug therapies (ART) and/or calcium and vitamin D supplements.

Objective:

To determine whether patients with Crohn's disease at risk for osteoporosis or already having decreased BMD were identified as such and treated with appropriate therapy.

Methods:

A cross-sectional study was performed among 54 white patients with Crohn's disease who attended a gastroenterology specialized clinic between January and March 2002. All patients with Crohn's disease having an outpatient medical visit were asked to participate in the study. Patients who agreed to the study were questioned for Crohn's disease activity index (CDAI) and osteoporosis risk factors such as nutrition, lifestyle, and corticosteroid therapy. Serum bone-specific markers and nutritional status were assessed. BMD test of the lumbar vertebrae (L2–L4) and the nondominant hip were assessed with dual-energy X-ray absorptiometry if the participants did not have a BMD test in the year prior to the study. ART and calcium/vitamin D use were assessed through a questionnaire and on community pharmaceutical drug services in the 2 year period prior to the evaluation.

Results:

Mean age and CDAI severity score were 41.5 years and 145, respectively. None of the patients was evaluated for BMD in the year prior to the study. Osteopenia at the nondominant hip and/or lumbar vertebrae was seen in 29 patients. Eighty-two percent of patients with a T score under −2 SD had not been exposed to ART; 84% of patients with more than 4 risk factors for osteoporosis and a T score less than −1.5 SD had not received ART. Moreover, 88% of patients with a T score less than −1.5 SD and receiving corticosteroid therapy had not been treated with ART.

Conclusions:

The presence of osteoporosis risk factors and osteopenia had not been recognized and treated in our population. Adequate osteoporosis management should be implemented in patients with Crohn's disease to reduce the occurrence of osteoporotic fractures.

The nucleocytoplasmic shuttling protein CIZ reduces adult bone mass by inhibiting bone morphogenetic protein-induced bone formation

Osteoporosis is a major health problem; however, the mechanisms regulating adult bone mass are poorly understood. Cas-interacting zinc finger protein (CIZ) is a nucleocytoplasmic shuttling protein that localizes at cell adhesion plaques that form where osteoblasts attach to substrate. To investigate the potential role of CIZ in regulating adult bone mass, we examined the bones in CIZ-deficient mice. Bone volume was increased and the rates of bone formation were increased in CIZ-deficient mice, whereas bone resorption was not altered. CIZ deficiency enhanced the levels of mRNA expression of genes encoding proteins related to osteoblastic phenotypes, such as alkaline phosphatase (ALP) as well as osterix mRNA expression in whole long bones. Bone marrow cells obtained from the femora of CIZ-deficient mice revealed higher ALP activity in culture and formed more mineralized nodules than wild-type cells. CIZ deficiency enhanced bone morphogenetic protein (BMP)–induced osteoblastic differentiation in bone marrow cells in cultures, indicating that BMP is the target of CIZ action. CIZ deficiency increased newly formed bone mass after femoral bone marrow ablation in vivo. Finally, BMP-2–induced bone formation on adult mouse calvariae in vivo was enhanced by CIZ deficiency. These results establish that CIZ suppresses the levels of adult bone mass through inhibition of BMP-induced activation of osteoblasts.

Nocturia, nocturnal polyuria, and sleep quality in the elderly

Nocturia is a common symptom in the elderly, which profoundly influences general health and quality of life. One consequence of nocturia is sleep deterioration, with increased daytime sleepiness and loss of energy and activity. Accidents, e.g., fall injuries, are increased both at night and in the daytime in elderly persons with nocturia. Nocturia is caused by nocturnal polyuria, a reduced bladder capacity, or a combination of the two. Nocturnal polyuria can be caused by numerous diseases, such as diabetes insipidus, diabetes mellitus, congestive heart failure, and sleep apnoea. In the nocturnal polyuria syndrome (NPS), the 24-h diuresis is normal or only slightly increased, while there is a shift in diuresis from daytime to night. NPS is caused by a disturbance of the vasopressin system, with a lack of nocturnal increase in plasma vasopressin or, in some cases, no detectable levels of the hormone at any time of the 24-h period. The calculated prevalence of NPS is about 3% in an elderly population, with no gender difference. In NPS, there are serious sleep disturbances, partly due to the need to get up for micturition, but there is also increased difficulty in falling asleep after nocturnal awakenings and increased sleepiness in the morning. The treatment of NPS may include avoidance of excessive fluid intake, use of diuretics medication in the afternoon rather than the morning, and desmopressin orally at bedtime.

Lack of insulin-like growth factor I exaggerates the effect of calcium deficiency on bone accretion in mice

Recent studies provide evidence that the GH/IGF-I axis plays a critical role in the regulation of bone accretion that occurs during puberty and that the peak bone mineral density (BMD) is dependent on the amount of dietary calcium intake during the active growth phases. To evaluate whether IGF-I deficiency exaggerates the effect of calcium deficiency on bone accretion during active growth phases, IGF-I knockout (KO) and wild-type (WT) mice were fed with low calcium (0.01%) or normal calcium (0.6%) for 2 wk during the pubertal growth phase and were labeled with tetracycline. The low calcium diet caused significant decreases in endosteal bone formation parameters and a much greater increase in the resorbing surface of both the endosteum and periosteum of the tibia of IGF-I KO mice compared with WT mice. Accordingly, femur BMD measured by dual energy x-ray absorptiometry or peripheral quantitative computed tomography increased significantly in IGF-I WT mice fed the low calcium diet, but not in IGF-I KO mice. IGF-I-deficient mice fed the normal calcium diet showed elevated PTH levels, decreased serum 1,25-dihydroxyvitamin D and serum calcium levels at baseline. Serum calcium changes due to calcium deficiency were greater in IGF-I KO mice compared with WT mice. PTH levels were 7-fold higher in IGF-I KO mice fed normal calcium compared with WT mice, which was further elevated in mice fed the low calcium diet. Treatment of IGF-I-deficient lit/lit mice with GH decreased the serum PTH level by 70% (P < 0.01). Based on these and past findings, we conclude that: 1) IGF-I deficiency exaggerates the negative effects of calcium deficiency on bone accretion; and 2) IGF-I deficiency may lead to 1,25-dihydroxyvitamin D deficiency and elevated PTH levels even under normal calcium diet.

Hormone replacement therapy and the risk of incident congestive heart failure: the Cardiovascular Health Study

BACKGROUND

The development of congestive heart failure (CHF) in older persons is related to a variety of mechanisms. Hormone replacement therapy (HRT) affects several of the pathways that may be important in the development of CHF. We hypothesized that HRT would be associated with a decreased risk of incident CHF.

METHODS

Using Cox proportional-hazards regression, we assessed the risk of incident CHF (n = 304) associated with time-dependent past and current use of HRT compared to never use. The Cardiovascular Health Study is a prospective cohort study of community-dwelling adults aged 65 years and older. This analysis included female participants without a history of CHF at baseline (n = 3223).

RESULTS

At baseline, 62% were never users, 26% were past users, and 12% were current users of HRT. Compared with never users, the multivariable relative risk (RR) of CHF was 1.01 (95% confidence interval [95% CI] 0.76,1.34) for past users and 1.34 (0.93,1.94) for current users. Results were similar among most treatment and clinical subgroups, except that the association of current HRT with CHF appeared to depend on body mass index (BMI) or osteoporosis status. The RR was 0.82 (0.43,1.60) for normal weight women, 1.65 (0.95,2.88) for overweight women, and 2.22 (1.06,4.67) for obese women (p = 0.01 for interaction). Similarly, the RR was 0.15 (0.04,0.65) for women with osteoporosis and 1.82 (1.25,2.65) for women without osteoporosis (p = 0.001 for interaction).

CONCLUSIONS

Overall, HRT was not associated with the risk of incident CHF, although BMI and osteoporosis appeared to modify the association of HRT with CHF. The risk of CHF was lower in patients with lower BMI or osteoporosis.

Relationship between age and lower extremity fractures in frontal motor vehicle collisions

BACKGROUND

Older adults (aged > or = 65 years) represent the single fastest growing segment of the United States population and will comprise one in five Americans during the third decade of this century. As this population segment rapidly expands, lower extremity fractures (LE Fx) and their associated disability will become a greater public health concern. The purpose of this study was to quantify the risk for LE Fx from motor vehicle collisions (MVCs) according to age.

METHODS

The 1995 to 2000 National Automotive Sampling System data files were used. Study entry was limited to front-seat occupants involved in frontal MVCs. Risk ratios for LE Fx and age were adjusted for gender, driver versus passenger, seat belt use, airbag deployment, delta-V, intrusion, and vehicle type.

RESULTS

Beginning in the fourth decade, there was a trend of higher relative risk for LE Fx with age that reached statistical significance in the seventh decade of life.

CONCLUSION

This study documented an increased risk of LE Fx in older MVC occupants. Efforts to prevent these disabling injuries and to better protect occupants' lower extremities in MVCs should include improved vehicle design and reevaluation of the existing federal motor vehicle safety standards.

Premature menopause in a multi-ethnic population study of the menopause transition

BACKGROUND

Premature menopause, also termed premature ovarian failure (POF), is characterized by cessation of menstruation before the age of 40 years. Little information is available on the general prevalence of POF or on the prevalence by ethnic group. There is also a lack of information on the association of POF with health indicators.

METHODS

A cross-sectional survey of women aged 40-55 years was conducted at seven sites in the USA to determine eligibility for a community-based, multi-ethnic longitudinal study of the peri-menopause (The Study of Women Across the Nation, SWAN). Interview data were used to (i). determine the prevalence of self-reported POF overall and by ethnic group, and (ii). assess the association of POF with selected self-reported variables related to health. Cases of POF included only women with no discernible cause for POF.

RESULTS

POF was reported by 1.1% (126/11 652) of women. By ethnicity, 1.0% (95% CI, 0.7-1.4) of Caucasian, 1.4% (95% CI, 1.0-2.1) of African American, 1.4% (95% CI, 0.8-2.5) of Hispanic, 0.5% (95% CI, 0.1-1.9) of Chinese and 0.1% (95% CI, 0.02-1.1) of Japanese women experienced POF. The differences in frequency across ethnic groups were statistically significant (P = 0.01). Only Caucasian, African American and Hispanic women were included in further analyses since too few Asian women had POF. In a multivariate model, POF was independently associated with osteoporosis, female hormone use (excluding oral contraceptives), higher body mass index (BMI) and current smoking after adjustment for education level, ability to pay for basics, site and age at interview. In Caucasian women, use of female hormones, osteoporosis, severe disability and smoking were significantly associated with POF. In contrast, POF in African American women was associated with higher BMI and female hormone use, but not osteoporosis.

CONCLUSIONS

The prevalence of POF appears to vary by ethnicity. Health factors associated with POF also vary by ethnicity but because of the cross-sectional study design, it is not possible to determine cause and effect relationships. Health risks of POF would benefit from further study.

Ginsenoside-Rb1 acts as a weak phytoestrogen in MCF-7 human breast cancer cells

Ginseng has been recommended to alleviate the menopausal symptoms, which indicates that components of ginseng very likely contain estrogenic activity. We have examined the possibility that a component of Panax ginseng, ginsenoside-Rb1, acts by binding to estrogen receptor. We have investigated the estrogenic activity of ginsenoside-Rb1 in a transient transfection system using estrogen-responsive luciferase plasmids in MCF-7 cells. Ginsenoside-Rb1 activated the transcription of the estrogen-responsive luciferase reporter gene in MCF-7 breast cancer cells at a concentration of 50 microM. Activation was inhibited by the specific estrogen receptor antagonist ICI 182,780, indicating that the estrogenic effect of ginsenoside-Rb1 is estrogen receptor dependent. Next, we evaluated the ability of ginsenoside-Rb1 to induce the estrogen-responsive gene c-fos by semi-quantitative RT-PCR assays and Western analyses. Ginsenoside-Rb1 increased c-fos both at mRNA and protein levels. However, ginsenoside-Rb1 failed to activate the glucocorticoid receptor, the retinoic acid receptor, or the androgen receptor in CV-1 cells transiently transfected with the corresponding steroid hormone receptors and hormone responsive reporter plasmids. These data support our hypothesis that ginsenoside-Rb1 acts a weak phytoestrogen, presumably by binding and activating the estrogen receptor.

Estradiol represses human T-cell leukemia virus type 1 Tax activation of tumor necrosis factor-alpha gene transcription

Adult T-cell leukemia is caused by human T-cell leukemia virus type I (HTLV-I). The HTLV-I Tax protein is essential for clinical manifestations because it activates viral and cellular gene transcription. Tax enhances production of tumor necrosis factor-alpha (TNF-alpha), which may lead to bone and joint destruction. Because estrogens might prevent osteoporosis by repressing TNF-alpha gene transcription, we investigated whether estrogens inhibit the transcriptional effects of Tax on the TNF-alpha promoter. Tax activated the -1044, -163, and -125 TNF-alpha promoters by 9-25-fold but not the -82 promoter, demonstrating that Tax activation requires the -125 to -82 region, known as the TNF response element (TNF-RE). Three copies of the TNF-RE upstream of the minimal thymidine kinase promoter conferred a similar magnitude of activation by Tax. We demonstrated that c-Jun, NFkappaB, p50, and p65 interact with and activate the TNF-RE by using mutational analysis of the TNF-RE, Tax mutants that selectively activate NFkappaB or the cAMP-response element binding protein/activating transcription factor pathway, and gel shift assays with nuclear extracts. Estradiol markedly repressed Tax-activated transcription of the TNF-alpha gene with estrogen receptor (ER) alpha or beta. Nuclear extracts from U2OS cells stably transfected with ER(alpha) demonstrated that ERs interact with the TNF-RE. Our studies provide evidence that ERs repress Tax-activated TNF-alpha transcription by interacting with a c-Jun and NFkappaB platform on the TNF-RE. Estrogens may ameliorate bone and inflammatory joint diseases in patients infected with HTLV-I by repressing transcription of the TNF-alpha gene.

A longitudinal study of bone density in midlife women

A longitudinal study of 386 healthy Black and White women aged 35-60 years was conducted to determine the effects of physical activity and other related factors on lumbar bone mineral density over 24 months. Bone mineral density of the lumbar spine, L2-L4, was measured using dual energy x-ray (Hologic 1000). Physical activity levels in three dimensions (leisure, household, and occupational) from both a lifelong and current perspective were obtained by questionnaire. Body mass index was calculated from measured weight in kilograms divided by measured height in meters squared. Calcium, caffeine, and alcohol intake was estimated using a food frequency questionnaire. Age, race, and smoking were determined by self-report. Radioimmunoassays of follicle stimulating hormone (FSH) and estradiol were used to validate self-reports of menopausal status. Multiple regression analysis revealed that race, age, weight, FSH, calcium, and years of tobacco intake formed the best model at baseline (r(2) = 0.32) and at 24 months (r(2) = 0.303). Physical activity was not a significant predictor for bone mineral density at either time point. There were cross-sectional changes of bone mineral density with race, age, and menopausal status. Black women had significantly higher bone mineral density than White women. However, an age-related decline in bone mineral density was exhibited in both Black and White women. Perimenopausal women had significantly lower bone mineral density as compared with premenopausal women. Furthermore 37 (9.6%) women at baseline and 34 (11%) at 24 months were designated at risk for fracture.

Evaluating and treating exercise-related menstrual irregularities

Menstrual abnormalities, from a few skipped periods to a complete absence of menses, are extremely common in both athletic and nonathletic adolescents and women in their early 20s. Exercise-related menstrual abnormality is linked with hypothalamic pituitary axis dysfunction and is a diagnosis of exclusion. In athletes, treatment of secondary menstrual abnormalities and associated health concerns, such as bone density, may include medication and restriction from activity.

Estrogen receptor beta-selective transcriptional activity and recruitment of coregulators by phytoestrogens

Estrogens used in hormone replacement therapy regimens may increase the risk of developing breast cancer. Paradoxically, high consumption of plant-derived phytoestrogens, particularly soybean isoflavones, is associated with a low incidence of breast cancer. To explore the molecular basis for these potential different clinical outcomes, we investigated whether soybean isoflavones elicit distinct transcriptional actions from estrogens. Our results demonstrate that the estrogen 17beta-estradiol effectively triggers the transcriptional activation and repression pathways with both estrogen receptors (ERs) ERalpha and ERbeta. In contrast, soybean isoflavones (genistein, daidzein, and biochanin A) are ERbeta-selective agonists of transcriptional repression and activation at physiological levels. The molecular mechanism for ERbeta selectivity by isoflavones involves their capacity to create an activation function-2 surface of ERbeta that has a greater affinity for coregulators than ERalpha. Phytoestrogens may act as natural selective estrogen receptor modulators that elicit distinct clinical effects from estrogens used for hormone replacement by selectively recruiting coregulatory proteins to ERbeta that trigger transcriptional pathways.