Osteoporosis and atherosclerosis: biological linkages and the emergence of dual-purpose therapies

The association between the non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and the risk of osteoporosis among U.S. adults: analysis of NHANES data

BACKGROUND

Osteoporosis and atherosclerosis frequently afflict older adults, and recent insights suggest a deeper connection between these conditions that surpasses mere aging effects. The ratio of non-high-density to high-density lipoprotein cholesterol (NHHR) has emerged as a novel lipid marker for evaluating the risk of cardiovascular diseases. Nonetheless, investigations into the correlation of the NHHR with the risk of developing osteoporosis remain unexplored.

METHODS

We collected NHHR and bone mineral density (BMD) data from 11,024 National Health and Nutrition Examination Survey (NHANES) participants between 2011 and 2018. Multivariate linear regression was employed to examine the correlation between BMD and NHHR. Smooth curves were employed to deal with the nonlinearity. To further account for the nonlinear link, we used a two-part linear regression model. The threshold effects were estimated using two components of a linear regression model. Subgroup and sensitivity analyses were carried out to ascertain the stability of the findings.

RESULTS

We discovered a negative relationship between the NHHR and lumbar spine BMD in all three models. An L-shaped curvilinear association existed between the NHHR and lumbar spine BMD, with a key inflection point of 6.91. The fully adjusted model showed that the BMD of the lumbar spine fell by 0.03 g/cm2 in those who were in the fourth quartile as opposed to the lowest quartile. The sensitivity analysis using unweighted logistic analysis verified the stability of the results. In addition, BMD in the nondiabetic group was more significantly affected by the negative effect of the NHHR in the subgroup analysis.

CONCLUSIONS

According to this research, there appears to be a negative correlation between BMD and NHHR in US Adults. To clarify the precise physiological mechanisms by which the NHHR contributes to the onset of osteoporosis, more research is necessary.

The Identification Potential of Atherosclerotic Calcifications in the Context of Forensic Anthropology

Atherosclerosis is an inflammatory disease that, in its more developed stages, can lead to the calcification of fatty plaques on the walls of arteries, resulting in the appearance of new bone elements. It is a condition that has been studied and documented little in the context of paleopathology, especially in the framework of forensic anthropology. This article analyzed the skeletal remains of 71 individuals (35 females and 36 males) from the Luís Lopes Identified Collection of the National Museum of Natural History and Science in Lisbon, 31 of whom had an autopsy report. An attempt was made to ascertain whether these bone elements resulting from atherosclerotic calcification would resist cadaveric decomposition and whether they would be recoverable several years after burial, and a survey was carried out of their distribution according to sex and age, as well as their association with other pathologies, such as osteoporosis and cardiac and renal pathologies. An imaging analysis of an atherosclerotic plaque was also carried out to complement the macroscopic analysis and present other methods of identifying plaques. It was concluded that each atherosclerotic calcification has a unique profile, which can be useful for identification, especially in cases where the individual shows a severe condition. In terms of identification potential, the analysis of calcified atherosclerotic plaques can be useful, as they can corroborate or reject an identification. However, it always requires the existence of ante-mortem imaging exams and must always be used in addition to other identification methods. Regardless of the identification, these plaques are bone elements resulting from a pathology and should, therefore, be known and recognized by the scientific community.

Osteoporosis and cardiovascular disease: a review

BACKGROUND

Osteoporosis and cardiovascular disease are common diseases encountered globally, especially with advancing age. Osteoporosis occurs when there is a loss of bone mineral density leading to increased predisposition to fragility fracture. The conventional perception of osteoporosis is purely as a metabolic bone disease. However, there are mounting reports from recent studies that osteoporosis could be seen as a risk factor for cardiovascular disease just like other traditional risk factors such as hypertension, dyslipidaemia and diabetes. This is a paradigm shift with regards to the outlook of osteoporosis. Osteoporosis and cardiovascular disease have similar risk factors, including diabetes, smoking, excess alcohol, sedentary lifestyle, ageing and dyslipidaemia. This may partly explain the link between osteoporosis and cardiovascular disease. In addition, both osteoporosis and atherosclerosis, which underlies most cardiovascular disease, are both characterized by low grade chronic inflammation. Moreover, the processes involved in the calcification of atheroma are similar to what is seen in bone remodeling. Both processes also involve similar regulators such as osteoprotegerin and related proteins such as osteonectin, osteopontin and type 1 collagen are found in bone matrix and atheromatous plaques.

CONCLUSION

There is emerging evidence that individuals with osteoporosis are also at an increased risk of coronary artery disease and stroke even after controlling for other factors. The traditional risk factors for cardiovascular disease also predispose people to developing osteoporosis, suggesting that the same mechanism may be causing the two. Moreover, a number of anti-osteoporotic drugs have also been largely linked with cardiovascular disease. This calls for a change in the view of osteoporosis as a metabolic disease but as a cardio-metabolic disorder thereby emphasizing the need for intensified preventive strategies for the disease.

Understanding the Stony Bridge between Osteoporosis and Vascular Calcification: Impact of the FGF23/Klotho axis

A relationship between osteoporosis (OP) and vascular calcification (VC) is now proposed. There are common mechanisms underlying the regulation of them. Fibroblast growth factor- (FGF-) 23 and Klotho are hormones associated with the metabolic axis of osteovascular metabolism. Most recently, it was suggested that the FGF23-klotho axis is associated with increasing incidence of fractures and is potentially involved in the progression of the aortic-brachial stiffness ratio. Herein, we discussed the potential role of the FGF23/Klotho axis in the pathophysiology of OP and VC. We want to provide an update review in order to allow a better understanding of the potential role of the FGF23/Klotho axis in comorbidity of OP and VC. We believe that a better understanding of the relationship between both entities can help in proposing new therapeutic targets for reducing the increasing prevalence of OP and VC in the aging population.

Atherosclerosis and Bone Loss in Humans-Results From Deceased Donors and From Patients Submitted to Carotid Endarterectomy

Background and Aims: Atherosclerosis and osteoporosis share common risk factors, as well as inflammatory mechanisms. Our aim was to understand how atherosclerotic lesions are related with disturbances in bone.

Methods: Gene expression of pro-inflammatory and bone metabolism related proteins (IL-1β, IL-6, IL-17A, TNF, RANKL, OPG, COL1, CTSK, OCL, TRAP, CBFA1, DKK1, SOST, ADIPOQ, and ADIPOR1) were analyzed in arteries and bones from 45 deceased donors and adipose tissue was used as control. Additionally, in 139 patients with advanced atherosclerosis submitted to carotid endarterectomy we compared calcium content (Alizarin red) and plaque inflammatory scores (CD3⁺, CD68⁺, and adiponectin) of patients with normal bone mineral density (BMD) with those with low BMD and explored the associations between gene expression in atherosclerotic plaques and BMD. Serum levels of pro-inflammatory and bone related proteins were measured both in donors and patients. Associations were investigated by the Pearson or Spearman correlation tests, and multivariate regression analyzes were performed when justified.

Results: Gene expression of bone remodeling and pro-inflammatory proteins correlated positively in bone and aorta, independently of age and sex of donors, but not in adipose tissue. The expression of bone formation genes was significantly higher in atheroma plaques from endarterectomized patients with normal vs. low BMD as well as inflammatory CD68⁺ scores, regardless of patients' age and sex, but not of body mass index. No relationship was observed between serum levels and gene expression levels of pro-inflammatory or bone remodeling proteins.

Conclusions: Our results suggest that the relationship between bones and vessels in the context of atherosclerotic disease and osteoporosis may rely on the intrinsic connection between the tissues involved, independently of disease stage. Serum measurements of pro-inflammatory and bone-remodeling proteins do not accurately translate tissue pathologic processes.

Association between the cumulative exposure to bisphosphonates and hospitalization for atherosclerotic cardiovascular events: A population-based study

BACKGROUND AND AIMS

Although bisphosphonates have been suggested to protect against atherosclerotic cardiovascular (CV) events, evidence is still conflicting. We aimed at investigating the effect of bisphosphonates on hospitalizations for atherosclerotic CV events.

METHODS

We carried out a retrospective cohort study selecting subjects aged>40 years, incident users of bisphosphonates. Exposure to bisphosphonates was characterized based on cumulative doses (proportion of days covered, PDC). Treatment's adherence was classified as low (PDC≤40%), intermediate (PDC 41%-80%), or high (PDC>80%). A multivariate Cox model was fitted to estimate the association between cumulative time-dependent exposure to bisphosphonates and hospitalization for atherosclerotic CV events (hazard ratio [HR] and 95% confidence interval).

RESULTS

Among 82,704 new bisphosphonates users (females 87.0%, mean age 70.7 ± 10.6 years), 16.1% had a CV hospitalization during a mean follow-up of 6.5 + 2.6 years. Compared with individuals with PDC ≤40%, those exposed for 41-80% or more than 80% showed HRs of CV hospitalization of 0.95 [0.91-0.99] and 0.75 [0.71-0.81], respectively. In the sub-analysis by type of event, a PDC >80% was associated with a reduced incidence for both coronary and cerebrovascular events (HRs 0.75 [0.68-0.83] and 0.76 [0.70-0.83], respectively). The protective effect was confirmed in stratified analyses by sex and age classes, and in those performed at 1 and 3 years of follow-up.

CONCLUSIONS

Strict adherence to bisphosphonate treatment was associated with a better CV outcome. Although further studies to investigate possible mechanisms are warranted, bisphosphonates could be considered as having a potential CV benefit beyond the effect on bones.

Lipidomic architecture shared by subclinical markers of osteoporosis and atherosclerosis: The Cardiovascular Risk in Young Finns Study

BACKGROUND

Studies have shown that osteoporosis and atherosclerosis are comorbid conditions sharing common risk factors and pathophysiological mechanisms. Understanding these is crucial in order to develop shared methods for risk stratification, prevention, diagnosis and treatment. The aim of this study was to apply a system-level bioinformatics approach to lipidome-wide data in order to pinpoint the lipidomic architecture jointly associated with surrogate markers of these complex comorbid diseases.

SUBJECTS AND METHODS

The study was based on the Cardiovascular Risk in Young Finns Study cohort from the 2007 follow-up (n = 1494, aged 30-45 years, women: 57%). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyse the serum lipidome, involving 437 molecular lipid species. The subclinical osteoporotic markers included indices of bone mineral density and content, measured using peripheral quantitative computer tomography from the distal and shaft sites of both the tibia and the radius. The subclinical atherosclerotic markers included carotid and bulbus intima media thickness measured with high-resolution ultrasound. Weighted co-expression network analysis was performed to identify networks of densely interconnected lipid species (i.e. lipid modules) associated with subclinical markers of both osteoporosis and atherosclerosis. The levels of lipid species (lipid profiles) of each of the lipid modules were summarized by the first principal component termed as module eigenlipid. Then, Pearson's correlation (r) was calculated between the module eigenlipids and the markers. Lipid modules that were significantly and jointly correlated with subclinical markers of both osteoporosis and atherosclerosis were considered to be related to the comorbidities. The hypothesis that the eigenlipids and profiles of the constituent lipid species in the modules have joint effects on the markers was tested with multivariate analysis of variance (MANOVA).

RESULTS

Among twelve studied molecular lipid modules, we identified one module with 105 lipid species significantly and jointly associated with both subclinical markers of both osteoporosis (r = 0.24, p-value = 2 × 10^-20) and atherosclerosis (r = 0.16, p-value = 2 × 10^-10). The majority of the lipid species in this module belonged to the glycerolipid (n = 60), glycerophospholipid (n = 13) and sphingolipid (n = 29) classes. The module was also enriched with ceramides (n = 20), confirming their significance in cardiovascular outcomes and suggesting their joint role in the comorbidities. The top three of the 37 statistically significant (adjusted p-value < 0.05) lipid species jointly associated with subclinical markers of both osteoporosis and atherosclerosis within the module were all triacylglycerols (TAGs) - TAG(18:0/18:0/18:1) with an adjusted p-value of 8.6 × 10^-8, TAG(18:0/18:1/18:1) with an adjusted p-value of 3.7 × 10^-6, and TAG(16:0/18:0/18:1) with an adjusted p-value of 8.5 × 10^-6.

CONCLUSION

This study identified a novel lipid module associated with both surrogate markers of both subclinical osteoporosis and subclinical atherosclerosis. Alterations in the metabolism of the identified lipid module and, more specifically, the TAG related molecular lipids within the module may provide potential new biomarkers for testing the comorbidities, opening avenues for the emergence of dual-purpose prevention measures.

mTORC1 and mTORC2 Differentially Regulate Cell Fate Programs to Coordinate Osteoblastic Differentiation in Mesenchymal Stromal Cells

Vascular regeneration depends on intact function of progenitors of vascular smooth muscle cells such as pericytes and their circulating counterparts, mesenchymal stromal cells (MSC). Deregulated MSC differentiation and maladaptive cell fate programs associated with age and metabolic diseases may exacerbate arteriosclerosis due to excessive transformation to osteoblast-like calcifying cells. Targeting mTOR, a central controller of differentiation and cell fates, could offer novel therapeutic perspectives. In a cell culture model for osteoblastic differentiation of pluripotent human MSC we found distinct roles for mTORC1 and mTORC2 in the regulation of differentiation towards calcifying osteoblasts via cell fate programs in a temporally-controlled sequence. Activation of mTORC1 with induction of cellular senescence and apoptosis were hallmarks of transition to a calcifying phenotype. Inhibition of mTORC1 with Rapamycin elicited reciprocal activation of mTORC2, enhanced autophagy and recruited anti-apoptotic signals, conferring protection from calcification. Pharmacologic and genetic negative interference with mTORC2 function or autophagy both abolished regenerative programs but induced cellular senescence, apoptosis, and calcification. Overexpression of the mTORC2 constituent rictor revealed that enhanced mTORC2 signaling without altered mTORC1 function was sufficient to inhibit calcification. Studies in mice reproduced the in vitro effects of mTOR modulation with Rapamycin on cell fates in vascular cells in vivo. Amplification of mTORC2 signaling promotes protective cell fates including autophagy to counteract osteoblast differentiation and calcification of MSC, representing a novel mTORC2 function. Regenerative approaches aimed at modulating mTOR network activation patterns hold promise for delaying age-related vascular diseases and treatment of accelerated arteriosclerosis in chronic metabolic conditions.

Bisphosphonate use and incident cardiovascular events among older breast cancer survivors

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of mortality in early-stage breast cancer survivors. Recent studies suggest that bisphosphonates may decrease CVD risk in older patients.

OBJECTIVE

This study sought to assess whether bisphosphonate use is associated with lower rates of incident CVD events among early-stage breast cancer survivors.

METHODS

Longitudinal, population-based cohort study was conducted by using data from the Surveillance, Epidemiology and End Results registry linked to Medicare claims. We identified women >65 years with no history of CVD who were diagnosed with stage 0-III primary breast cancer between 2007 and 2010. Our primary outcome was a composite of incident angina pectoris, myocardial infarction, atrial fibrillation/flutter, heart failure, or stroke within 36 months of cancer diagnosis. Bisphosphonate use was defined as the presence of ≥1 pharmacy claim from 6 months prior to cancer diagnosis to the incident CVD event. We used propensity scores to create a matched group of breast cancer survivors without bisphosphonate exposure to compare rates of incident CVD events.

RESULTS

A total of 2178 breast cancer survivors had ≥1 bisphosphonate prescription; the average length of bisphosphonate use was 15 months. Analyses of the matched data showed that 13.0% of bisphosphonate users and 23.4% of non-bisphosphonate users experienced an incident CVD event (p < 0.0001) after breast cancer diagnosis. Bisphosphonate use was significantly associated with fewer incident CVD events (hazard ratio: 0.51, 95% confidence interval: 0.44 to 0.59).

CONCLUSIONS

Bisphosphonate use is associated with lower incidence of CVD events among older early-stage breast cancer survivors. Future studies should prospectively evaluate whether bisphosphonate use can decrease CVD incidence.

Low bone mineral density is associated with global coronary atherosclerotic plaque burden in stable angina patients

Background

Accelerated atherosclerosis is considered to be the linking factor between low bone mineral density (BMD) and increased cardiovascular events and mortality, while some coronary angiographic studies do not support this point. In this study, we attempt to provide a distinct comprehensive view of the relationship between BMD and the angiographically determined coronary atherosclerotic burden.

Methods

A total of 459 consecutive patients with stable chest pain suspected of coronary artery disease (CAD) underwent both dual-energy X-ray absorptiometry scan and selective coronary angiography. The association between BMD and global coronary atherosclerotic plaque burden as represented by the multivessel involvement and the modified Gensini score was analyzed.

Results

Multivariable analysis revealed that the low BMD at femoral neck and total hip was an independent correlate of multivessel CAD. The T-scores measured at femoral neck and total hip were both negatively and independently associated to the modified Gensini score. These inversely correlated relationships between BMD and CAD were not observed at lumbar spine 1–4.

Conclusion

This cross-sectional study elucidated an inverse relationship between hip BMD and the modified Gensini score, and low hip BMD values (T-scores) were significantly and independently associated with increased risk of multivessel coronary disease in patients hospitalized for stable chest pain.

Compartment-resolved Proteomic Analysis of Mouse Aorta during Atherosclerotic Plaque Formation Reveals Osteoclast-specific Protein Expression

Atherosclerosis leads to vascular lesions that involve major rearrangements of the vascular proteome, especially of the extracellular matrix (ECM). Using single aortas from ApoE knock out mice, we quantified formation of plaques by single-run, high-resolution mass spectrometry (MS)-based proteomics. To probe localization on a proteome-wide scale we employed quantitative detergent solubility profiling. This compartment- and time-resolved resource of atherogenesis comprised 5117 proteins, 182 of which changed their expression status in response to vessel maturation and atherosclerotic plaque development. In the insoluble ECM proteome, 65 proteins significantly changed, including relevant collagens, matrix metalloproteinases and macrophage derived proteins. Among novel factors in atherosclerosis, we identified matrilin-2, the collagen IV crosslinking enzyme peroxidasin as well as the poorly characterized MAM-domain containing 2 (Mamdc2) protein as being up-regulated in the ECM during atherogenesis. Intriguingly, three subunits of the osteoclast specific V-ATPase complex were strongly increased in mature plaques with an enrichment in macrophages thus implying an active de-mineralization function.

Knee subchondral bone perfusion and its relationship to marrow fat and trabeculation on multi-parametric MRI and micro-CT in experimental CKD

The pathogenesis of chronic kidney disease (CKD) is multifactorial. In the progression of CKD arthropathy, arteriosclerosis may alter the knee subchondral bone marrow by altering blood flow through the bone vasculature. Herein, multi-parametric MRI assessment, including dynamic contrast enhanced magnetic resonance imaging (DCE-MRI), magnetic resonance spectroscopy (MRS), MRI T2*, contrast enhanced MR angiography (CE-MRA), and micro-CT were applied in a rodent nephrectomy model to: 1) investigate the blood perfusion of subchondral bone marrow and its relationship to fat water content and trabeculation pattern in CKD and 2) demonstrate the feasibility of using multi-parametric MRI parameters as imaging biomarkers to evaluate the disease’s progression. Two groups of rats in our study underwent either 1) no intervention or 2) 5/6 nephrectomy. We found that in the CKD group, perfusion amplitude A and elimination constant k_el values were significantly decreased, and vascular permeability k_ep was significantly increased. MRS showed that fat fraction (FF) was significantly lower, water fraction (WF) was significantly higher in the CKD group. Micro-CT showed a significant loss of trabecular bone. Knee subchondral bone marrow perfusion deficiency in experimental CKD may be associated with decreased fat content, increased water content, and sparse trabeculation.

Association between bisphosphonate therapy and outcomes from rehabilitation in older people

BACKGROUND

Bisphosphonate therapy may have actions beyond bone, including effects on cardiovascular, immune and muscle function. We tested whether bisphosphonate treatment is associated with improved outcomes in older people undergoing inpatient rehabilitation.

METHODS

Analysis of prospectively collected, linked routine clinical datasets. Participants were divided into never users of bisphosphonates, use prior to rehabilitation only, use after rehabilitation only, and current users (use before and after rehabilitation). We calculated change in 20-point Barthel scores during rehabilitation, adjusting for comorbid disease and laboratory data using multivariable regression analysis. Cox regression analyses were performed to analyse the association between bisphosphonate use and time to death or hospitalisation.

RESULTS

2797 patients were included in the analysis. Current bisphosphonate users showed greater improvement in Barthel score during rehabilitation than non-users (5.0 points [95%CI 4.3-5.7] vs 3.8 [95%CI 3.6-3.9]), but no difference compared to those receiving bisphosphonates only after discharge (5.1 [95%CI 4.6-5.5]). Previous bisphosphonate use was significantly associated with time to death (adjusted hazard ratio 1.41 [95%CI 1.15-1.73]) but less strongly with time to combined endpoint of hospitalisation or death (adjusted hazard ratio 1.18 [95%CI 0.98-1.48]). Use after discharge from rehabilitation was associated with reduced risk of death (adjusted hazard ratio 0.64 [95%CI 0.55-0.73]; hazard ratio per year of bisphosphonate prescription 0.98 [95%CI 0.97-0.99]).

CONCLUSION

Bisphosphonate use is unlikely to be causally associated with improved physical function in older people, but continuing use may be associated with lower risk of death.

The Association between Bone Quality and Atherosclerosis: Results from Two Large Population-Based Studies

OBJECTIVE

It is highly debated whether associations between osteoporosis and atherosclerosis are independent of cardiovascular risk factors. We aimed to explore the associations between quantitative ultrasound (QUS) parameters at the heel with the carotid artery intima-media thickness (IMT), the presence of carotid artery plaques, and the ankle-brachial index (ABI).

METHODS

The study population comprised 5680 men and women aged 20-93 years from two population-based cohort studies: Study of Health in Pomerania (SHIP) and SHIP-Trend. QUS measurements were performed at the heel. The extracranial carotid arteries were examined with B-mode ultrasonography. ABI was measured in a subgroup of 3853 participants. Analyses of variance and linear and logistic regression models were calculated and adjusted for major cardiovascular risk factors.

RESULTS

Men but not women had significantly increased odds for carotid artery plaques with decreasing QUS parameters independent of diabetes mellitus, dyslipidemia, and hypertension. Beyond this, the QUS parameters were not significantly associated with IMT or ABI in fully adjusted models.

CONCLUSIONS

Our data argue against an independent role of bone metabolism in atherosclerotic changes in women. Yet, in men, associations with advanced atherosclerosis, exist. Thus, men presenting with clinical signs of osteoporosis may be at increased risk for atherosclerotic disease.

Novel association between bone mineral density scores and the prevalence of peripheral artery disease in both sexes

The purpose of the current study was to investigate the association between bone mineral density (BMD) scores and the prevalence of peripheral artery disease (PAD) in a large cohort of subjects who underwent arterial Doppler assessments and calcaneal bone densitometry. The study was performed using data obtained from Life Line Screening Inc. Subjects were self-selected and paid for screening tests. The prevalence of PAD was significantly higher in men with osteopenia (4.5%) and osteoporosis (10.9%) compared to men with normal BMD (3.0%) ( p<0.001). Osteopenia (odds ratio (OR) 1.3) and osteoporosis (OR 2.3) were found to be independent risk factors for the presence of PAD in men. The prevalence of PAD was significantly higher in women with osteopenia (4.8%) and osteoporosis (11.8%) compared to women with normal BMD (3.3%) ( p<0.001). Osteopenia (OR 1.15) and osteoporosis (OR 1.8) were found to be independent risk factors for the presence of PAD in women. The current study reports a strong association of abnormal BMD analysis with the prevalence of PAD, which persists even when controlling for age and associated atherosclerotic risk factors. Although the mechanism by which these two disease processes is related is not completely elucidated, the presence of osteoporosis should make clinicians aware of the possibility of occult PAD or associated atherosclerotic disease in appropriate patients.

Risk factors of mortality during the first year after low energy osteoporosis fracture: a retrospective case-control study

INTRODUCTION

Osteoporotic fractures are a major public health problem because of the morbidity and mortality of fracture complications. The objective of this study was to examine predictive factors of mortality during the first year after an osteoporotic fracture.

METHODS

It is a retrospective case-control study using data of a group of 1081 patients aged over 50 years with severe osteoporotic fractures by the Rennes university hospital emergency department from August 2007 to September 2008. Patients (cases) who died during the year following the fracture were compared with others who had survived (controls) one year after the fracture, matched on age, sex and type of fracture. Pre-fracture comorbidities and complications after the fractures were studied.

RESULTS

Forty-two cases and 126 controls were analyzed without significant differences in age, sex or type of fracture. On univariate analysis, previous neoplasia, neurodegenerative disease, walking aids, thromboembolic complication, post fracture infection, post fracture heart failure, post fracture acute respiratory failure were associated with more mortality after osteoporotic fracture. After multivariate analysis, only previous neoplasia (OR = 4.63 [1.79 - 11.95]; p = 0.02) and acute respiratory failure after fracture (OR = 28.15 [5.75 - 137.9]; p<0.001) were retained as predictive factors during the year following the fracture.

CONCLUSION

Patients died more often from their co-morbidities than direct complications of their fractures. Osteoporotic fracture seems to be a marker of poor health status and a factor which may hasten the death.

Association of adipokines and estradiol with bone and carotid calcifications in postmenopausal women

OBJECTIVES

Carotid artery calcifications (CAC) and high carotid artery intima-media thickness (cIMT) are associated with low bone mineral density (BMD) by unknown mechanisms in postmenopausal women. Leptin, adiponectin and estradiol may mediate these associations. Our aim was to study the relationships of the aforementioned factors to bone health (BMD) and carotid atherosclerosis (CAC and cIMT).

METHOD

Participants (n = 290, mean age 73.6 years) for this cross-sectional OSTPRE-BBA study (Kuopio Osteoporosis Risk Factor and Prevention - Bone, Brain and Atherosclerosis) were randomly selected from the OSTPRE cohort in 2009. Femoral neck and total body BMDs, trunk and total body fat mass were measured with dual-energy X-ray absorptiometry, and cIMT (mm) and CAC (no/yes) were measured with B-type ultrasound. Free estradiol, adiponectin and leptin were measured from serum samples.

RESULTS

Circulating estradiol levels were associated with leptin (β = 0.131, p < 0.001), but not with adiponectin (p > 0.05), when adjusted for total body fat mass. There were no associations between estradiol tertiles and BMDs, or with cIMT or CAC. Adiponectin levels were inversely associated with femoral neck BMD (p = 0.019, β = -0.138) and total body BMD (p = 0.009, β = -0.142), adjusted for total body fat mass, age, current smoking and estradiol, but showed no relationship with CAC or cIMT. Leptin levels were not associated with BMDs or cIMT; but the odds ratio was 1.5 between the CAC and leptin quartiles (p = 0.014), adjusted for total body fat mass, age, statin use and calcium intake.

CONCLUSION

The adipokines are associated with vascular calcification and low BMD. Moreover, estradiol was not independently associated with BMD or CAC.

Osteoporosis Is Associated With High Risk for Coronary Heart Disease: A Population-Based Cohort Study

We employed a population-based cohort sample to explore the risk of coronary heart disease (CHD) in relation to osteoporosis in an Asian population.We designed a retrospective population-based cohort study from 2000 to 2010 with data obtained from Taiwan's Longitudinal Health Insurance Database. A total of 19,456 patients aged 45 years or older who had no history of CHD and had a diagnosis of osteoporosis were identified as the osteoporosis cohort. The patients in the comparison cohort were randomly selected and frequency matched according to age, sex, and year of index date at a 1:1 ratio. Both cohorts were followed from the index date until a new diagnosis of CHD was made. Baseline variables, comorbidities, and bisphosphonate and estrogen prescriptions were collected.The overall incidence of CHD was 23.5 (per 1000 person-years) for the osteoporosis cohort and 16.7 for the comparison cohort, with a mean follow-up of 6.54 years and 6.63 years, respectively. The hazard ratio (HR) for developing CHD during follow-up was 1.30 (95% confidence interval [CI], 1.23-1.38) for the osteoporosis cohort compared with the comparison cohort after adjusting for age, sex, comorbidities, and estrogen medication. Patients with osteoporosis who received treatment with bisphosphonates or with both bisphosphonates and estrogen exhibited a significantly lower risk for CHD (adjusted HR = 0.37 and 0.23) than those who did not receive either of these 2 medications.The results support an association between osteoporosis and CHD in Asian population.

Blood and interstitial flow in the hierarchical pore space architecture of bone tissue

There are two main types of fluid in bone tissue, blood and interstitial fluid. The chemical composition of these fluids varies with time and location in bone. Blood arrives through the arterial system containing oxygen and other nutrients and the blood components depart via the venous system containing less oxygen and reduced nutrition. Within the bone, as within other tissues, substances pass from the blood through the arterial walls into the interstitial fluid. The movement of the interstitial fluid carries these substances to the cells within the bone and, at the same time, carries off the waste materials from the cells. Bone tissue would not live without these fluid movements. The development of a model for poroelastic materials with hierarchical pore space architecture for the description of blood flow and interstitial fluid flow in living bone tissue is reviewed. The model is applied to the problem of determining the exchange of pore fluid between the vascular porosity and the lacunar-canalicular porosity in bone tissue due to cyclic mechanical loading and blood pressure. These results are basic to the understanding of interstitial flow in bone tissue that, in turn, is basic to understanding of nutrient transport from the vasculature to the bone cells buried in the bone tissue and to the process of mechanotransduction by these cells.

Impact of recipient-related factors on structural dysfunction of xenoaortic bioprosthetic heart valves

OBJECTIVE

To analyze the influence of recipient-related metabolic factors on the rate of structural dysfunction caused by the calcification of xenoaortic bioprostheses.

MATERIALS AND METHODS

We retrospectively analyzed clinical status, calcium-phosphorus metabolism, and nonspecific markers of inflammatory response in bioprosthetic mitral valve recipients with calcific degeneration confirmed by histological and electron microscopic studies (group 1, n=22), and in those without degeneration (group 2, n=48).

RESULTS

Patients with confirmed calcification of bioprostheses were more likely to have a severe clinical state (functional class IV in 36% in group 1 versus 15% in group 2, P=0.03) and a longer cardiopulmonary bypass period (112.8±18.8 minutes in group 1 versus 97.2±23.6 minutes in group 2, P=0.02) during primary surgery. Patients in group 1 demonstrated moderate hypovitaminosis D (median 34.0, interquartile range [21.0; 49.4] vs 40 [27.2; 54.0] pmol/L, P>0.05), osteoprotegerin deficiency (82.5 [44.2; 115.4] vs 113.5 [65.7; 191.3] pg/mL, P>0.05) and osteopontin deficiency (4.5 [3.3; 7.7] vs 5.2 [4.1; 7.2] ng/mL, P>0.05), and significantly reduced bone-specific alkaline phosphatase isoenzyme (17.1 [12.2; 21.4] vs 22.3 [15.5; 30.5] U/L, P=0.01) and interleukin-8 levels (9.74 [9.19; 10.09] pg/mL vs 13.17 [9.72; 23.1] pg/mL, P=0.045) compared with group 2, with an overall increase in serum levels of proinflammatory markers.

CONCLUSION

Possible predictors of the rate of calcific degeneration of bioprostheses include the degree of decompensated heart failure, the duration and invasiveness of surgery, and the characteristics of calcium-phosphorus homeostasis in the recipient, defined by bone resorption and local and systemic inflammation. The results confirm the hypothesis that cell-mediated regulation of pathological calcification is caused by dysregulation of metabolic processes, which are in turn controlled by proinflammatory signals.

Osteoporosis and cardiovascular disease: an update

Osteoporosis (OP) and cardiovascular diseases (CVD) are the most important causes of mortality and morbility in the elderly. Lots of studies showed a correlation between bone loss and cardiovascular risk mediated by the vascular calcification. The relationship between OP and CVD could be firstly explained by their common risk factors such as age, smoking, alcohol consumption, physical activity and menopause. However, other different hypotheses were proposed to clarify this link. Multiple factors, for example bone morphogenetic proteins, osteoprotegerin, receptor activator of nuclear factor κB ligand, parathyroid hormone, phosphate, oxidized lipids and vitamins D and K seemed to be involved in both conditions, indicating a possible common pathophysiologic mechanism. We review and discuss the available data describing this association. Further studies are necessary to better investigate similarities between OP and CVD.

The hallmarks of osteoarthritis and the potential to develop personalised disease-modifying pharmacological therapeutics

Osteoarthritis (OA) is an age-related condition and the leading cause of pain, disability and shortening of adult working life in the UK. The incidence of OA increases with age, with 25% of the over 50s population having OA of the knee. Despite promising preclinical data covering various molecule classes, there is regrettably at present no approved disease-modifying OA drugs (DMOADs). With the advent of next generation sequencing technologies, other therapeutic areas, in particular oncology, have experienced a paradigm shift towards defining disease by its molecular composition. This paradigm shift has enabled high resolution patient stratification and supported the emergence of personalised or precision medicines. In this review we evaluate the potential for the development of OA therapeutics to undergo a similar paradigm shift given that OA is increasingly being recognised as a heterogeneous disease affecting multiple joint tissues. We highlight the evidence for the role of these tissues in OA pathology as different "hallmarks" of OA biology and review the opportunities to identify and develop targeted disease-modifying pharmacological therapeutics. Finally, we consider whether it is feasible to expect the emergence of personalised disease-modifying medicines for patients with OA and how this might be achieved.

Effects of intravenous zoledronate and ibandronate on carotid intima-media thickness, lipids and FGF-23 in postmenopausal osteoporotic women

OBJECTIVE

Osteoporosis and atherosclerosis are interconnected entities and share also some pathophysiological mechanisms. Moreover, recent literature data have supported the hypothesis that bisphosphonates (BPs) may have some antiatherogenic actions. This study aimed to evaluate the effects of one year with zoledronate or ibandronate given intravenously on lipid profile and on carotid artery intima-media thickness (CA-IMT).

METHODS

Sixty postmenopausal osteoporotic women (mean age: 66.6±7.8years) were randomly assigned to 1-year treatment with zoledronate 5mg i.v. annually or ibandronate 3mg i.v. every 3 months. In all patients at baseline and after 12months we measured CA-IMT, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), 25-hydroxyvitamin D (25OHD), bone alkaline phosphatase (B-ALP), type I collagen β carboxy telopeptide (βCTX), osteocalcin (OC), fibroblast growth factor 23 (FGF-23) and sclerostin.

RESULTS

The osteoporotic women treated with zoledronate showed a greater reduction in CA-IMT than those treated with ibandronate. HDL-C and HDL-C/LDL-C ratio showed a significant (p<0.01) increase in the 2 groups, whereas, LDL-C showed a reduction in the two groups which, however, reached statistical significance (p<0.05) only in the zoledronate group. FGF-23 serum levels showed a similar and significant decrease in both the women treated with zoledronate and in those treated with ibandronate. At the end of the study period sclerostin serum levels showed a higher increase in the patients treated with zoledronate than in those treated with ibandronate.

CONCLUSION

In osteoporotic women both zoledronate and ibandronate given intravenously resulted in an increase in HDL-C/LDL-C ratio and a reduction of CA-IMT which was significant only for zoledronate. Further prospective studies are needed to clarify whether the change in FGF-23 and sclerostin levels is a marker or a potential mechanism of the action of BPs at a vascular level.

Bone metabolism regulators and arterial stiffness in postmenopausal women

BACKGROUND

Osteoprotegerin (OPG), osteopontin (OPN) and matrix Gla protein (MGP) are markers of bone metabolism but they are also involved in vascular calcification. However, their precise role is not completely understood. Arterial stiffness is considered an independent predictor of cardiovascular events and it may be one of the causes of the increased cardiovascular risk associated with postmenopausal status. Medial and intimal calcification may increase arterial stiffness. The aim of our study was to assess the relationship of OPG, OPN and MGP with aortic pulse wave velocity (aPWV) as a marker of arterial stiffness in postmenopausal women.

MATERIALS AND METHODS

Circulating OPG, OPN and serum total MGP were measured in 144 postmenopausal women using the enzyme-linked immunosorbent assay method. Aortic PWV was determined by an oscillometric method.

RESULTS

Osteoprotegerin correlated with age (p<0.001, r=0.27), aPWV (p<0.001, r=0.32) and hypersensitive C reactive protein (hsCRP) (p<0.001, r=0.37), OPN correlated directly with hsCRP (p<0.001, r=0.39) and inversely with high density lipoprotein cholesterol (p=0.02, r=-0.02). No significant association was found between total MGP and clinical, biochemical and vascular parameters. The correlation between OPG and aPWV persisted even after the adjustment for various potential confounders (p=0.02, r=0.19). In multiple regression analysis in the whole study population the most important predictors of aPWV were OPG (β=0.230, p=0.006), hsCRP (β=0.212, p=0.01) and systolic blood pressure (β=0.163, p=0.04). After exclusion of patients treated with statins the independent predictors were hsCRP (β=0.275, p=0.005) and OPG (β=0.199, p=0.04).

CONCLUSION

Circulating OPG, but not OPN and total MGP, is associated with aPWV and may be a marker of the increased arterial stiffness and cardiovascular risk in postmenopausal women.

Osteoporosis and atherosclerosis: a post-mortem MDCT study of an elderly cohort

OBJECTIVES

To evaluate how far fracture status and bone mineral density (BMD) correlate with the vascular calcification score (CS).

METHODS

On 29 complete human cadavers (17 female, 12 male; mean age at death was 85.57 years), multi-detector computed tomography was performed to assess the spine fracture status (fracture vs non-fracture [FX vs non-FX]) and CS of the coronary arteries (Coro-CS), the aorta (Aorta-CS) and the pelvic vessels (Iliac-CS). Quantitative computed tomography of the lumbar spine was performed to estimate overall BMD (osteoporotic [BMD <80 mg/cm(3)] vs non-osteoporotic [BMD ≥ 80 mg/cm(3)]).

RESULTS

Gender-specific differences in statistical significance were only observed for Aorta-CS and Iliac-CS but not for Coro-CS. When comparing the osteoporotic with the non-osteoporotic group, statistically significant differences were only found for Iliac-CS (P < 0.05); however, linear regression analysis showed none of the CSs to significantly correlate with BMD.

CONCLUSIONS

In our small post-mortem elderly population, statistically significant associations of fracture status and BMD with CS were only observed between the osteoporotic and non-osteoporotic groups for the pelvic vessels but not for the coronary arteries and the aorta.

KEY POINTS

• Gender-specific differences were observed for aortic and iliac calcification score (CS). • There was no difference in coronary CS between females and males. • Only iliac CS was different in osteoporotic and non-osteoporotic subjects. • In linear regression analysis, CS showed no correlation with BMD. • In univariate analysis, gender was a BMD and iliac CS confounder.

Bisphosphonate use is associated with reduced risk of myocardial infarction in patients with rheumatoid arthritis

Bisphosphonates have been shown to reduce mortality in patients with osteoporotic fractures, but the mechanism is unclear. Bisphosphonates have immunomodulatory effects that may influence the development of vascular disease. We sought to determine if bisphosphonate use is associated with a reduced risk of myocardial infarction (MI) in a rheumatoid arthritis (RA) population with high prevalence of bisphosphonate use and vascular disease. Adult patients with RA enrolled in the National Data Bank for Rheumatic Diseases, a longitudinal study of RA patients enrolled continuously from U.S. rheumatology practices between 2003 and 2011, were included in the analysis (n = 19,281). Patients completed questionnaires every 6 months. including questions on medication use, demographic information, clinical information, and health status. MIs were confirmed by a central adjudicator. Among the 5689 patients who were treated with bisphosphonates at some time during the study period, the risk of MI while on bisphosphonate compared to when not on bisphosphonate was 0.56 (95% confidence interval [CI], 0.37-0.86; p < 0.01) after adjustment for multiple confounders. In models including all 19,281 treated and untreated patients, the adjusted risk of first MI was 0.72 (95% CI, 0.54-0.96; p = 0.02) and of all MIs it was 0.72 (95% CI, 0.53-0.97; p = 0.03) in bisphosphonate users compared to nonusers. This finding suggests a potential mechanism for the mortality reduction observed with bisphosphonate medications.

Association of bone mineral density with albuminuria and estimated glomerular filtration rate: the Dong-gu Study

BACKGROUND

Kidney dysfunction and albuminuria may be associated with BMD. However, little evidence has been reported on relationships between BMD and eGFR and albuminuria.

METHODS

A total of 8,992 subjects aged 50 years or older participated in a survey conducted. Participants had their lumbar spine and femoral neck BMD measured by a Lunar Prodigy bone densitometer (GE, Madison, WI). Kidney function was assessed using MDRD eGFR and diagnosis of albuminuria was based on albumin-creatinine ratio.

RESULTS

ACR was negatively associated with lumbar spine and femur neck BMD in females (lumbar spine: 1.001, 0.988, 0.974 and 0.979 g/cm(2), p < 0.001; femur neck: 0.796, 0.790, 0.783 and 0.782 g/cm(2), p = 0.002), but not in males, after adjusting for covariates. Additionally, eGFR was shown to be negatively associated with lumbar spine BMD after adjusting for covariates (male: 1.181, 1.166, 1.152 and 1.149 g/cm(2), p = 0.001; female: 0.997, 0.980, 0.979 and 0.982 g/cm(2), p = 0.005), but demonstrated no association with femur BMD.

CONCLUSIONS

ACR in females was negatively associated with lumbar spine and femur neck BMD, but not in males. eGFR was negatively associated with lumbar spine BMD in both males and females.

Relationship between MRI-measured bone marrow adipose tissue and hip and spine bone mineral density in African-American and Caucasian participants: the CARDIA study

CONTEXT

An increasing number of studies suggest that bone marrow adipose tissue (BMAT) might play a role in the pathogenesis of osteoporosis. Our previous study of Caucasian women demonstrated that there is an inverse relationship between BMAT and whole-body bone mineral density (BMD). It is unknown whether visceral adipose tissue (VAT), sc adipose tissue (SAT), and skeletal muscle had an effect on the relationship between BMAT and BMD.

OBJECTIVE

In the present study we investigated the relationship between pelvic, hip, and lumbar spine BMAT with hip and lumbar spine BMD in the population-based Coronary Artery Risk Development in Young Adults (CARDIA) sample with adjustment for whole-body magnetic resonance imaging (MRI)-measured VAT, SAT, and skeletal muscle.

DESIGN

T1-weighted MRI was acquired for 210 healthy African-American and Caucasian men and women (age 38-52 yr). Hip and lumbar spine BMD were measured by dual-energy x-ray absorptiometry.

RESULTS

Pelvic, hip, and lumbar spine BMAT had negative correlations with hip and lumbar spine BMD (r = -0.399 to -0.550, P < 0.001). The inverse associations between BMAT and BMD remained strong after adjusting for demographics, weight, skeletal muscle, SAT, VAT, total adipose tissue (TAT), menopausal status, lifestyle factors, and inflammatory markers (standardized regression coefficients = -0. 296 to -0.549, P < 0.001). Among body composition measures, skeletal muscle was the strongest correlate of BMD after adjusting for BMAT (standardized regression coefficients = 0.268-0.614, P < 0.05), with little additional contribution from weight, SAT, VAT, or total adipose tissue.

CONCLUSION

In this middle-aged population, a negative relationship existed between MRI-measured BMAT and hip and lumbar spine BMD independent of demographics and body composition. These observations support the growing evidence linking BMAT with low bone density.

Future of anticathepsin K drugs: dual therapy for skeletal disease and atherosclerosis?

BACKGROUND

Until fairly recently, cathepsin K was recognized solely as a bone-resorbing enzyme expressed selectively in the osteoclast. Evidence of its requirement for normal bone remodeling has resulted in this protease receiving considerable attention from the pharmaceutical industry. In the last decade, intense research efforts were aimed at development of cathepsin K inhibitors for treatment of osteoporosis and other skeletal disorders associated with pathological bone loss. Emerging new evidence suggests that in addition to bone resorption, cathepsin K is involved in the turnover of extracellular matrix proteins in organs, such as the lung, thyroid and skin, and plays important roles in cardiovascular disease, inflammation and obesity.

DISCUSSION

This review highlights the physiological and pathophysiological implications of this potent protease, with a focus on recent developments in the design and use of cathepsin K inhibitors to target skeletal pathologies. Therapeutic implications of anticathepsin K drugs in the context of common links between bone disease and atherosclerosis are also discussed.

CONCLUSION

The association of cathepsin K with skeletal and cardiovascular disorders offers intriguing future applications for inhibitors of this potent protease.

Molecular dynamics simulation of mammalian 15S-lipoxygenase with AMBER force field

A molecular dynamics simulation study of mononuclear iron 15S-lipoxygenase (15S-LOX) from rabbit reticulocytes was performed to investigate its structure and dynamics; newly developed AMBER force field parameters were employed for the first coordination sphere of the catalytic iron (II). The results obtained from this study demonstrate that the structural features of the catalytic iron coordination site are in good agreement with available data obtained from experiments. The motional flexibility of the N-terminal β-barrel domain is greater than the C-terminal catalytic domain; flexibility was assessed in terms of B-factors and secondary structure calculations. The significant features obtained for the relative motional flexibility of these two domains of 15S-LOX in solution as well as the isolated C-terminal domain were analyzed in terms of radius of gyration and maximum diameter, which correlated well with the structural flexibility of 15-lipoxygenase-1 in solution as probed by small-angle X-ray scattering. The motional flexibility indicates interdomain motion between the N-terminal β-barrel and the C-terminal catalytic domain; this was further verified by the evaluation of central bending in the solvated LOX molecule, which identified an unstructured stretch of amino acids as the interdomain linker. The average bending angle confirmed significant central bending between these two domains, which was linked to the high degree of motional freedom of the N-terminal β-barrel domain in aqueous solutions. This can be considered to have biological relevance for membrane binding as well as for regulating the catalytic domain.

Association between coronary artery calcification using low-dose MDCT coronary angiography and bone mineral density in middle-aged men and women

Six hundred sixty-one participants who had at least one cardiac risk factor but were without known coronary heart disease underwent low-dose multidetector computed tomography coronary angiography (MDCT-CA) and dual-energy X-ray absorptiometry. The association between presence of subclinical coronary calcified plaque and low bone mineral density for the middle-aged individual was not significant after multivariate adjustment.

INTRODUCTION

Results of previous clinical studies assessing the relationship between osteoporosis and coronary calcification are inconsistent. This study aimed to evaluate the association between subclinical coronary calcification and osteoporosis in middle-aged men, premenopausal women, and postmenopausal women by using low-dose MDCT-CA and bone mineral density (BMD).

METHODS

This study enrolled 661 participants with at least one cardiac risk factor but without known coronary artery disease (CAD). All subjects underwent low-dose MDCT-CA and dual-energy X-ray absorptiometry on the same day.

RESULTS

The mean age was 52.2 years for men, 44.8 years for premenopausal women, and 59.1 years for postmenopausal women. The prevalence of calcified plaques between men with normal BMD and low BMD at lumbar spine were significantly different (P=0.042). The prevalence of mixed plaque and calcified plaque between pre- and postmenopausal women with normal BMD and low BMD at lumbar spine and femoral neck were not significantly different (P>0.05). Possible association between lumbar spine, femoral neck, and total proximal femur BMD and the presence of CAP was evaluated for men, premenopausal women, and postmenopausal women using multivariate logistic regression analysis: results were not significant (P>0.05).

CONCLUSION

Our study demonstrates that the association between the presence of subclinical coronary calcification and low BMD among middle-aged men and women was not significant after controlling for age and other risk factors for CAD and osteoporosis.

(Sub)clinical cardiovascular disease is associated with increased bone loss and fracture risk; a systematic review of the association between cardiovascular disease and osteoporosis

Introduction

Both cardiovascular disease and osteoporosis are important causes of morbidity and mortality in the elderly. The co-occurrence of cardiovascular disease and osteoporosis prompted us to review the evidence of an association between cardiovascular (CV) disease and osteoporosis and potential shared common pathophysiological mechanisms.

Methods

A systematic literature search (Medline, Pubmed and Embase) was conducted to identify all clinical studies that investigated the association between cardiovascular disease and osteoporosis. Relevant studies were screened for quality according to guidelines as proposed by the Dutch Cochrane Centre and evidence was summarized.

Results

Seventy studies were included in this review. Due to a large heterogeneity in study population, design and outcome measures a formal meta-analysis was not possible. Six of the highest ranked studies (mean n = 2,000) showed that individuals with prevalent subclinical CV disease had higher risk for increased bone loss and fractures during follow-up compared to persons without CV disease (range of reported risk: hazard ratio (HR) 1.5; odds ratio (OR) 2.3 to 3.0). The largest study (n = 31,936) reported a more than four times higher risk in women and more than six times higher risk in men. There is moderate evidence that individuals with low bone mass had higher CV mortality rates and incident CV events than subjects with normal bone mass (risk rates 1.2 to 1.4). Although the shared common pathophysiological mechanisms are not fully elucidated, the most important factors that might explain this association appear to be, besides age, estrogen deficiency and inflammation.

Conclusions

The current evidence indicates that individuals with prevalent subclinical CV disease are at increased risk for bone loss and subsequent fractures. Presently no firm conclusions can be drawn as to what extent low bone mineral density might be associated with increased cardiovascular risk.

Thoracoabdominal calcifications predict cardiovascular disease mortality in type 2 diabetic and nondiabetic subjects: 18-year follow-up study

OBJECTIVE To evaluate cardiovascular disease (CVD) and total mortality associated with thoracoabdominal calcifications. RESEARCH DESIGN AND METHODS Thoracoabdominal calcifications of native radiograms were evaluated in 833 subjects with type 2 diabetes and 1,292 subjects without diabetes, aged 45-64 years, without prior evidence of CVD. The type 2 diabetic and nondiabetic study cohorts were followed up for 18 years. RESULTS After adjustment for conventional risk factors, marked thoracoabdominal calcifications predicted CVD/total mortality with hazard ratio (HR) (95% CI) of 1.5 (0.8-3.0)/1.8 (1.1-2.9) in type 2 diabetic men, 3.0 (1.6-5.7)/3.1 (1.9-5.0) in type 2 diabetic women, 5.0 (2.2-12)/4.0 (2.2-7.4) in nondiabetic men, and 7.8 (1.8-34)/3.0 (1.3-7.0) in nondiabetic women and in the presence of C-reactive protein below/over 3 mg/l with HR of 2.4 (1.3-4.4)/3.0 (1.4-6.1) in type 2 diabetic subjects and 4.0 (1.5-10.8)/6.6 (2.7-16.0) in nondiabetic subjects. CONCLUSIONS Thoracoabdominal calcifications in native radiograms are significant predictors of CVD and total mortality, especially in type 2 diabetic and nondiabetic women with elevated high-sensitivity C-reactive protein level.

Regulation of interleukin-6 expression in osteoblasts by oxidized phospholipids

Epidemiological evidence suggests that cardiovascular disease is associated with osteoporosis, independent of age. Bone resorptive surface is increased in mice on a high-fat diet, and osteoclastic differentiation of bone marrow preosteoclasts is promoted by oxidized phospholipids. Because osteoclastic differentiation requires cytokines produced by osteoblasts, we hypothesized that the stimulatory mechanism of oxidized phospholipids is via induction of osteoclast-regulating cytokines in osteoblasts. To investigate the effects of oxidized phospholipids on expression of such cytokines, murine calvarial preosteoblasts, MC3T3-E1, were treated with oxidized 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphocholine (ox-PAPC), an active component of oxidized lipoproteins. Results showed that ox-PAPC increased expression of interleukin-6 (IL-6) and tumor necrosis factor-alpha. IL-6 expression was also elevated in calvarial tissues from hyperlipidemic but not in wild-type mice. Ox-PAPC also induced IL-6 protein levels in both MC3T3-E1 and primary calvarial cells. Promoter-reporter assay analysis showed that ox-PAPC, but not PAPC, induced murine IL-6 promoter activity. Effects of ox-PAPC on IL-6 expression and the promoter activity were attenuated by H89, a PKA inhibitor. Analysis of deletion and mutant IL-6 promoter constructs suggested that CAAT/enhancer binding protein (C/EBP) partly mediates the ox-PAPC effects. Taken together, the data suggest that oxidized phospholipids induce IL-6 expression in osteoblasts in part via C/EBP.

Low bone mineral density is related to atherosclerosis in postmenopausal Moroccan women

BACKGROUND

Some studies have implicated several possible metabolic linkages between osteoporosis and vascular calcification, including estrogen deficiency, vitamin D excess, vitamin K deficiency and lipid oxidation products. Nevertheless, it remains unclear whether osteoporosis and atherosclerosis are related to each other or are independent processes, both related to aging. The aim of this cross-sectional study was to evaluate the correlation between arterial thickening and bone status in a sample of apparently healthy Moroccan women.

METHODS

Seventy-two postmenopausal women were studied. All patients were without secondary causes that might affect bone density. Bone status was assessed by bone mineral density (BMD) in lumbar spine and all femoral sites. Arterial wall thickening was assessed by intima-media thickness (IMT) in carotid artery (CA) and femoral artery (FA). Prevalent plaques were categorized into four groups ranging from low echogenicity to high echogenicity.

RESULTS

The mean age was 59.2 +/- 8.3 years. 84.7% had at least one plaque. By Spearman Rank correlation, CA IMT was negatively correlated to Femoral total BMD (r = -0.33), Femoral neck BMD (r = -0.23), Ward triangle BMD (r = -0.30) and Trochanter BMD (r = -0.28) while there was no association with lumbar BMD. In multiple regression analysis, CA IMT emerged as an independent factor significantly associated with all femoral sites BMD after adjusting of confounding factors. FA IMT failed to be significantly associated with both Femoral and Lumbar BMD. No significant differences between echogenic, predominantly echogenic, predominantly echolucent and echolucent plaques groups were found concerning lumbar BMD and all femoral sites BMD CONCLUSION: Our results demonstrate a negative correlation between bone mineral density (BMD) qnd carotid intima-media thickness (IMT) in postmenopausal women, independently of confounding factors. We suggest that bone status should be evaluated in patients with vascular disease to assess whether preventive or therapeutic intervention is necessarry.

Integrated network systems and evolutionary developmental endocrinology

Endocrine system has been considered to be a linear one, but the 'real world endocrine system' is a complex system, which is difficult to investigate using conventional strategies, such as single nucleotide polymorphism, genome-wide analysis, or gene targeting in animals. Here we propose a new strategy to comprehend the endocrine system as a complex network system. We introduced several novel concepts, such as complex system, network analysis, systems biology and evolutionary medicine, into the comprehension of endocrine system as a whole complex network system. This system is considered to be a scale-free network with key molecules such as acetyl CoA, NAD or ATP as 'hubs'. This system is robust against simple mutations, but various complex diseases may attack hubs. The system is also 'fractals', since there exist similar network systems among cells, proteins, and transcription factors in the lower levels, and there are similar ones among disease and social network in the higher levels. We propose to call this model 'Integrated Network Systems and Evolutionary DEvelopmental ENdocrinology (INS-EDEN)'. This novel framework will facilitate us to develop a new approach for understanding and treatment of various complex diseases related to endocrinology, and identify a unified theory of complex diseases.

KLOTHO gene polymorphism is associated with coronary artery stenosis but not with coronary calcification in a Korean population

Experimental studies have demonstrated KLOTHO gene polymorphism might be associated with vascular atherosclerosis and calcification. However, the impact of this genetic variant on human coronary arteries still remains to be elucidated. We investigated the effect of a KLOTHO gene variant on coronary artery stenosis and calcification. Four hundred and thirty-four patients referred for chest pain were enrolled. All the patients underwent coronary angiography and were investigated for polymorphism of the KLOTHO G395A gene. Coronary artery disease (CAD) was defined as > or = 50% diameter stenosis in at least one coronary artery. The other patients were considered to be controls. Homozygotes or heterozygotes for G395A were significantly more common in the CAD patients than in the controls (30.2% versus 21.5%, P = 0.039). In the subgroup aged < 60 years, the G395A mutant was more frequent in CAD than in control (35.3% versus 18.8%, P = 0.016), but in patients > or = 60 years, there was no difference (28.0% versus 24.1%, P = 0.473). Using multivariate analysis, we identified the KLOTHO gene G395A mutant as an independent risk factor of CAD (OR 1.712, 95% CI [1.066-2.749], P = 0.026). The frequency of the KLOTHO gene G395A mutant was not different between the calcified and noncalcified coronary artery groups (25.7%, 26.4%, respectively, P = 0.861) and an A allele carrier state was not an independent risk factor of coronary artery calcification. In conclusion, the KLOTHO gene G395A allele carrier state may be associated with CAD but not with coronary artery calcification in this Korean population.

PPARs as new therapeutic targets for the treatment of cerebral ischemia/reperfusion injury

Stroke is a leading cause of death and long-term disability in industrialized countries. Despite advances in understanding its pathophysiology, little progress has been made in the treatment of stroke. The currently available therapies have proven to be highly unsatisfactory (except thrombolysis) and attempts are being made to identify and characterize signaling proteins which could be exploited to design novel therapeutic modalities. The peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that control lipid and glucose metabolism. PPARs regulate gene expression by binding with the retinoid X receptor (RXR) as a heterodimeric partner to specific DNA sequences, termed PPAR response elements. In addition, PPARs may modulate gene transcription also by directly interfering with other transcription factor pathways in a DNA-binding independent manner. To date, three different PPAR isoforms, designated alpha, beta/delta, and gamma, have been identified. Recently, they have been found to play an important role for the pathogenesis of various disorders of the central nervous system and accumulating data suggest that PPARs may serve as potential targets for treating ischemic stroke. Activation of all PPAR isoforms, but especially of PPARgamma, was shown to prevent post-ischemic inflammation and neuronal damage in several in vitro and in vivo models, negatively regulating the expression of genes induced by ischemia/ reperfusion (I/R). This paper reviews the evidence and recent developments relating to the potential therapeutic effects of PPAR-agonists in the treatment of cerebral I/R injury.

Atherosclerosis and osteoporosis: age-dependent degenerative processes or related entities?

Osteoporosis and atherosclerosis, two multifactorial and degenerative entities, are major public health problems. These diseases accompany the aging process and share common risk factors. Furthermore, several common pathophysiological factors have been suggested. These include similar molecular pathways involving bone and vascular mineralization, estrogen deficiency, parathyroid hormone, homocysteine, lipid oxidation products, inflammatory process, as well as vitamin D and K. Moreover, the use of statins, biphosphonates, beta-blockers and experimental dual-purpose therapies based on the biological linkage of the above entities may simultaneously benefit bone loss and vascular disease. This review considers a potential link between osteoporosis and atherosclerosis beyond aging. These common factors may lead to appropriate treatment strategies.