Low bone density is not associated with aortic calcification

Associations between bone mineral density and abdominal aortic calcification: Results of a nationwide survey

BACKGROUND AND AIMS

Vascular calcification has been linked to bone mineral density (BMD). This study aimed to investigate the association between BMD and abdominal aortic calcification (AAC).

METHODS AND RESULTS

Data from the 2013-2014 National Health and Nutrition Examination Survey (NHANES) were utilized. Participants lacking BMD and AAC score data were excluded. BMD at the femoral neck was measured using dual-energy X-ray absorptiometry. AAC scores were assessed using the Kauppila scoring system, with AAC defined as a score greater than zero, and severe AAC defined as a score greater than six. Weighted multivariable regression analysis and subgroup analysis were conducted to examine the independent relationship between BMD and AAC score, AAC, and severe AAC. A total of 2965 participants were included. After adjusting for multiple covariates, BMD showed a negative association with higher AAC scores (β = -0.17, 95% CI -0.29, -0.05, p = 0.0066). The odds of having AAC and severe AAC decreased by 9% and 16%, respectively, for every one-unit increase in BMD (AAC: odds ratio [OR] = 0.91, 95% CI 0.82, 1.00, p = 0.0431; severe AAC: OR = 0.84, 95% CI 0.71, 0.99, p = 0.0334).

CONCLUSION

Low BMD is associated with higher AAC scores and an increased risk of AAC and severe AAC. Considering the detrimental impact of low BMD on cardiovascular health, individuals with AAC should be evaluated for osteopenia and osteoporosis in clinical settings.

Heterotopic mineralization (ossification or calcification) in aged musculoskeletal soft tissues: A new candidate marker for aging

Aging can lead to various disorders in organisms and with the escalating impact of population aging, the incidence of age-related diseases is steadily increasing. As a major risk factor for chronic illnesses in humans, the prevention and postponement of aging have become focal points of research among numerous scientists. Aging biomarkers, which mirror molecular alterations at diverse levels in organs, tissues, and cells, can be used to monitor and evaluate biological changes associated with aging. Currently, aging biomarkers are primarily categorized into physiological traits, imaging characteristics, histological features, cellular-level alterations, and molecular-level changes that encompass the secretion of aging-related factors. However, in the context of the musculoskeletal soft tissue system, aging-related biological indicators primarily involve microscopic parameters at the cellular and molecular levels, resulting in inconvenience and uncertainty in the assessment of musculoskeletal soft tissue aging. To identify convenient and effective indicators, we conducted a comprehensive literature review to investigate the correlation between ectopic mineralization and age-related changes in the musculoskeletal soft tissue system. Here, we introduce the concept of ectopic mineralization as a macroscopic, reliable, and convenient biomarker for musculoskeletal soft tissue aging and present novel targets and strategies for the future management of age-related musculoskeletal soft tissue disorders.

Coronary calcification and bone microarchitecture by high-resolution peripheral quantitative computed tomography from the São Paulo Ageing and Health (SPAH) Study

Epidemiological studies reveal a link between osteoporosis and the risk of ischemic cardiovascular disease. We illustrate an association between coronary calcification and bone microarchitecture in older adults based on the SPAH study. This cross-sectional research comprised 256 individuals subjected to cardiac coronary computed tomography angiography (CCTA) for coronary artery calcification (CAC), high-resolution peripheral quantitative computed tomography (HR-pQCT) at the tibia and radius with standardized z score parameters, and dual-energy X-ray absorptiometry (DXA) to evaluate bone status. We used Student’s t test and the Mann–Whitney and Chi-squared tests for comparison of basal measurements. Association analysis was performed using the Poisson regression model with adjustment for CAC and sex. Multivariate analysis revealed different bone variables for predicting CAC in DXA and HR-pQCT scenarios. Although most of the bone parameters are related to vascular calcification, only cortical porosity (Ct.Po) remained uniform by HR-pQCT. Results for were as follows: the tibia—women (exp β = 1.12 (95% CI 1.10–1.13, p < 0.001) and men (exp β = 1.44, 95% CI 1.42–1.46, p < 0.001); the radius—women (exp β = 1.07 (95% CI 1.07–1.08, p < 0.001) and men (exp β = 1.33 (95% CI 1.30–1.37, p < 0.001). These findings suggest an inverse relationship between CAC and cortical bone content, as assessed by HR-pQCT, with higher coronary calcification in individuals older than 65 years.

Measuring forearm bone density instead of lumbar spine bone density improves the sensitivity of diagnosing osteoporosis in older adults with cardiovascular diseases: Data from SARCOS study

Introduction

In older individuals with cardiovascular diseases, it has been challenging to diagnose osteoporosis due to aortic calcification and degenerative processes in the spine of older adults, especially in very old adults.

Aim

To assess whether the distal forearm BMD with the proximal femur BMD has greater sensitivity for the diagnosis of osteoporosis than the lumbar spine BMD with the proximal femur BMD.

Methods

We evaluated 515 older adults with cardiovascular disease from the SARCOS study and stratified them into under and over 80-year-old age groups and according to gender. Two diagnostic criteria were used to assess osteoporosis, SPF (lumbar spine and proximal femur BMD) and DFF (distal forearm and proximal femur BMD), which were compared with the multiple bone sites (MS) criteria (lumbar spine, distal radius, femoral neck, and total femur BMD).

Results

43.9% were aged ≥80 years. Osteoporosis by SPF was diagnosed in 34% (n = 175), by DFF in 42.2% (n = 216), and by MS in 46.8% (n = 241). The characteristics of the three groups were similar. For every 100 older individuals with osteoporosis based on MS, 27 were not diagnosed by the SPF, and nine were not diagnosed by DFF (p = 0.001). The SPF did not diagnose osteoporosis in 23/100 in older adults aged <80 years, while DFF did not diagnose 16/100 (p.ns). In adults aged ≥80 years, the SPF did not identify osteoporosis in 31/100 older adults, while the DFF failed to identify it in only 5/100 (p < 0.001). In men and women aged ≥80 years, DFF showed higher sensitivity for the diagnosis of osteoporosis compared to the SPF criterion.

Conclusion

In the elderly population with cardiovascular disease evaluated in our study, the use of distal forearm BMD instead of lumbar spine BMD, associated with proximal femur BMD, showed higher sensitivity for the diagnosis of osteoporosis, regardless of gender, and especially among the very older adults.

•

Diagnosis of osteoporosis (OP) in the elderly with cardiovascular disease is challenging.

•

We evaluated the sensitivity of distal forearm (DF) BMD vs. lumbar spine (LS) BMD.

•

LS BMD did not diagnose OP in 27/100, and DF BMD in 9/100 (p = 0.001).

•

LS BMD did not identify OP in 31/100, and DF BMD in 5/100 (p < 0.001) aged ≥80 years.

•

DF BMD showed higher sensitivity for diagnosing osteoporosis, regardless of gender.

Ascending Aortic Calcification as a Potential Predictor for Low Bone Mineral Density: A Pilot Study

BACKGROUND

Identifying the factors related to low bone mineral density (BMD) can have significant implications for preventing hip fractures. The correlation between ascending aortic calcification and BMD has never been reported. Therefore, the purpose of the current study is to confirm the hypothesis that ascending aortic calcification can be used as a predictive factor for low BMD and to find a radiographic sign to show it.

METHOD

Plain film and computed tomography (CT) images of the thorax were obtained from 91 patients with hip fractures. Using the images, the calcification line of the ascending aorta adjacent to the aortic arch was evaluated. A prominent calcification line confirmed by both plain film and CT was classified as +2. A line which was ambiguous on plain film but confirmed by CT was classified as +1. Cases with no calcification were categorized as 0 (control). We compared the classified score with the BMD and calculated the kappa coefficient to measure intraobserver reliabilities for this radiographic finding.

RESULTS

Twenty-eight patients showed a +2 line, twenty-four patients showed a +1 line, and thirty-nine patients showed 0 lines. The median BMD of each group was 0.37 for the +2 line, 0.45 for the +1 line, and 0.51 for the 0 line. The BMD for the +2 group was significantly lower than the others. The kappa coefficient was approximately 0.6 (p < 0.01).

CONCLUSION

The imaging finding of calcification of the ascending aorta might be considered as a potential surrogate marker of low BMD. In such subjects, BMD might be ordered for the confirmation of diagnosis of osteoporosis. Mini-Abstract. The Aortic Arch Tail Sign, a calcification line on the ascending aorta, was relevant to low BMD in the current study. BMD can be ordered for the confirmation of diagnosis of osteoporosis in a subject incidentally found to have ascending aorta calcification on X-ray or CT.

Brief Report: Aging Attenuates the Association Between Coronary Artery Calcification and Bone Loss Among HIV-Infected Persons

INTRODUCTION

Studies among HIV-uninfected persons (mostly in their sixth decade of life) show that detectable coronary artery calcium (CAC) is independently associated with low bone mineral density (BMD), suggesting a possible common pathogenic mechanism.

AIM

We assessed the relationship between CAC and BMD, which has not been well described among younger to middle-aged HIV-infected persons.

METHODS

We studied participants with baseline CAC and BMD measures from a prospective cohort of HIV-infected persons enrolled in the Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy (SUN) during 2004-2006. We used logistic regression to assess the association between detectable CAC (>0 Agatston score) and BMD (g/cm, T-score), and adjusted for known traditional and HIV-related risk factors.

RESULTS

Among 472 participants (76% male, 30% non-Hispanic black, median age 41 years, and 71% with HIV RNA < 400 copies/mL), the majority had no detectable CAC (82%), but had baseline osteopenia (53%) or osteoporosis (10%). In univariate analysis, participants with detectable CAC had lower femoral neck/total hip T-scores, lower femoral neck/total hip/lumbar spine BMD, and higher rates of osteopenia/osteoporosis. After adjustment for age, all associations were no longer significant; adjustment for traditional risk factors excluding age and HIV-related variables failed to attenuate these associations.

CONCLUSIONS

We found aging attenuates the association between detectable CAC and BMD in this cohort. Aging remains an important contributor to non-AIDS-defining illnesses. These data reinforce the importance of developing screening and prevention strategies for aging HIV-infected persons given their excess risk across a wide spectrum of end-organ complications.

Changes in vascular calcification and bone mineral density in calcium supplement users from the Canadian Multi-center Osteoporosis Study (CaMOS)

BACKGROUND AND AIMS

Calcium supplements have been associated with increased cardiovascular events. This study investigates the relationship between calcium supplement use and the 5 year progression of abdominal aorta calcification (AAC) in participants from one center of the Canadian Multi-Centre Osteoporosis Study (CaMOS).

METHODS

Participants (n = 296; 217 women and 79 men) had lateral spine X-rays and DEXA bone mineral density (BMD) scans (femoral neck, lumbar spine and total hip) taken at two time points within a 5 year interval. AAC was assessed using the Framingham Method. Calcium supplement use was assessed by a facilitated health history questionnaire and medication inventory.

RESULTS

AAC significantly increased over 5 years, AAC progression was significantly greater in calcium supplement users, as compared to non-users, overall and in females. The amount of calcium was positively correlated to AAC progression. A multi-variable linear regression model was generated for women only, as there were not enough men for multivariable modelling. Calcium supplement use and amount remained significantly associated with AAC progression after adjustment for age, hypertension, diabetes and smoking history. Change in AAC score was not associated with change in BMD T-Score. In univariate analyses of males, calcium supplement use was associated with a significantly greater BMD loss at the lumbar spine, hip, and femoral neck.

CONCLUSIONS

Older female calcium supplement users had significantly higher AAC progression over 5 years, but did not have any significant BMD preservation. These results suggest that vascular calcification may contribute to the cardiovascular events observed in calcium supplement users.

Association Between Abdominal Aortic Calcification, Bone Mineral Density, and Fracture in Older Women

Although a relationship between vascular disease and osteoporosis has been recognized, its clinical importance for fracture risk evaluation remains uncertain. Abdominal aortic calcification (AAC), a recognized measure of vascular disease detected on single-energy images performed for vertebral fracture assessment, may also identify increased osteoporosis risk. In a prospective 10-year study of 1024 older predominantly white women (mean age 75.0 ± 2.6 years) from the Perth Longitudinal Study of Aging cohort, we evaluated the association between AAC, skeletal structure, and fractures. AAC and spine fracture were assessed at the time of hip densitometry and heel quantitative ultrasound. AAC was scored 0 to 24 (AAC24) and categorized into low AAC (score 0 and 1, n = 459), moderate AAC (score 2 to 5, n = 373), and severe AAC (score >6, n = 192). Prevalent vertebral fractures were calculated using the Genant semiquantitative method. AAC24 scores were inversely related to hip BMD ( r _s = -0.077, p = 0.013), heel broadband ultrasound attenuation ( r _s = -0.074, p = 0.020), and the Stiffness Index ( r _s = -0.073, p = 0.022). In cross-sectional analyses, women with moderate to severe AAC were more likely to have prevalent fracture and lumbar spine imaging-detected lumbar spine fractures, but not thoracic spine fractures (Mantel-Haenszel test of trend p < 0.05). For 10-year incident clinical fractures and fracture-related hospitalizations, women with moderate to severe AAC (AAC24 score >1) had increased fracture risk (HR 1.48; 95% CI, 1.15 to 1.91; p = 0.002; HR 1.46; 95% CI, 1.07 to 1.99; p = 0.019, respectively) compared with women with low AAC. This relationship remained significant after adjusting for age and hip BMD for clinical fractures (HR 1.40; 95% CI, 1.08 to 1.81; p = 0.010), but was attenuated for fracture-related hospitalizations (HR 1.33; 95% CI, 0.98 to 1.83; p = 0.073). In conclusion, older women with more marked AAC are at higher risk of fracture, not completely captured by bone structural predictors. These findings further support the concept that vascular calcification and bone pathology may share similar mechanisms of causation that remain to be fully elucidated © 2019 American Society for Bone and Mineral Research.

Low Bone Mineral Density Is Not Associated with Subclinical Atherosclerosis: A Population-Based Study in Rural China

OBJECTIVES

Loss of bone mass may affect the progression of atherosclerosis. We investigated the relationship between low bone mineral density (BMD) and subclinical atherosclerosis in rural China.

METHODS

In total, 333 men and 421 postmenopausal women aged 55-65 years were enrolled. BMD was measured in the lumbar spine, femoral neck, and total hip using dual-energy X-ray absorptiometry. Subclinical atherosclerosis was defined as increased carotid artery intima-media thickness (CIMT ≥0.9 mm), the presence of carotid plaques, high brachial-ankle pulse wave velocity (baPWV ≥1,400 cm/s), and low ankle-brachial index (ABI ≤1). Binary logistic regression analyses were used to estimate the association between low BMD and subclinical atherosclerosis.

RESULTS

There was no significant difference in BMD between the normal group and the subclinical atherosclerosis group. After full adjustment for the relevant covariates, a boundary significant association was found between low BMD in the femoral neck and baPWV in postmenopausal women (odds ratio = 1.77, p = 0.049). After full adjustment, neither BMD nor low BMD were significantly associated with subclinical atherosclerosis in men or postmenopausal women.

CONCLUSIONS

Low BMD is not associated with subclinical atherosclerosis in Chinese individuals aged 55-65 years resident in rural China.

In Type-2 Diabetes Subjects Trabecular Bone Score is Better Associated with Carotid Intima-Media Thickness than BMD

Literature data reported that in elderly subjects, carotid intima-media thickness (IMT) was negatively associated with bone mineral density (BMD). Paradoxically, type-2 diabetes (T2DM) patients, despite having higher BMD, present an increased risk of fragility fractures and cardiovascular complications. Some studies have reported trabecular bone score (TBS), an index of trabecular bone quality, as possibly being reduced in T2DM. This study aimed to evaluate whether in T2DM subjects TBS was better associated with IMT with respect to BMD. In 131 consecutive T2DM subjects (55 men and 76 women; mean age: 60.0 ± 7.3 years) and 265 consecutive non-T2DM subjects (107 men and 158 women; mean age: 58.9 ± 7.8 years) we measured carotid IMT by high-resolution ultrasonography and BMD at lumbar spine (LS-BMD), at femoral neck FN-BMD and total hip TH-BMD; TBS was calculated using TBS iNsight software. LS-BMD, FN-BMD, and TH-BMD were all significantly higher in T2DM than in non-T2DM subjects, whereas TBS was significantly lower in T2DM subjects than in controls and inversely correlated with diabetes duration. In T2DM subjects multiple regression analysis showed that IMT was positively associated with age (b = 0.017; p < 0.001) and inversely associated with TBS (b = -0.473; p = 0.038). In non-T2DM subjects, only age was positively associated with IMT. To sum up, T2DM subjects present higher values of BMD and lower values of TBS with respect to non-diabetic controls. Moreover, in T2DM subjects TBS was found to be independently associated with carotid IMT. These findings suggest that TBS may not only capture bone fragility-related factors, but also some information associated with greater risk of developing cardiovascular diseases.

Bone Density in Postmenopausal Women with or without Breast Arterial Calcification

BACKGROUND

Identification of osteoporosis in women in order to prevent its related morbidity and mortality is considered a priority. Routine mammography is performed on all menopausal women as a screening tool. Determination of the relation between breast arterial calcification (BAC) on mammography and the bone density of this high-risk population could help us to determine those with osteoporosis. The aim of this study was to investigate the mentioned probable relation between BAC and osteoporosis.

MATERIALS AND METHODS

In this cross-sectional study, menopausal women referred for annual screening mammography were enrolled. According to the results of mammography, they were classified into two groups: menopausal women with and without calcification of breast arteries. The selected women were referred for bone mineral density (BMD) evaluation by dual-energy x-ray absorptiometry (DXA). The results of BMD were compared between the two studied groups.

RESULTS

In this study, BMD was measured in 43 and 45 menopausal women with and without BAC, respectively. After age adjustment the difference between BMD measurements were not statistically significantly different (P > 0.05). There was a significant negative correlation between age and lumbar (P = 0.002, r = -0.42) and hip bone (P = 0.000, r = -0.67) density in menopausal women with BAC.

CONCLUSION

The results of the current study indicated that there was no significant relationship between BAC and BMD in our studied population, but it seems that increasing age has an important role in both developing BAC and reducing BMD. For obtaining more conclusive results, further studies with larger sample sizes and considering the severity of BAC is recommended.

Decreased Bone Mineral Density Is an Independent Predictor for the Development of Atherosclerosis: A Systematic Review and Meta-Analysis

Background

There is conflicting evidence regarding the association between decreased bone mineral density (BMD) and atherosclerosis. To this end, we performed a systematic review and meta-analysis to clarify the association.

Methods

To identify relevant studies, PubMed, Embase, and the Cochrane Library were systematically searched up to November 2015. All observational and comparative studies directly investigating the relationship between decreased BMD and clinical consequences of atherosclerotic vascular abnormalities, including carotid artery calcification (CAC), cardiovascular disease (CAD), and coronary artery disease (CAD) were obtained, without limitation of language or publication year.

Results

A total of 25 studies involving 10,299 patients were included. The incidence of atherosclerotic vascular abnormalities was significantly increased in low BMD patients, compared to patients with normal BMD (OR, 1.81, 95% CI [1.01, 2.19], p<0.00001)). Similar results were also observed for postmenopausal women (OR, 2.23, 95% CI [1.72, 2.89], p<0.00001). Subgroup analyses of osteopenia, osteoporosis, and normal BMD also revealed that the combined ORs for the incidence of atherosclerotic vascular abnormalities increased as BMD decreased. Of note, after adjusting for age, sex, body mass index (BMI) and other vascular risk factors, decreased BMD remained significantly associated with the incidence of atherosclerotic vascular abnormalities (OR, 2.96, 95% CI [2.25, 3.88], p < 0.00001).

Conclusions

Based on the results of this study, decreased BMD is an independent predictor for the development of atherosclerosis in elderly individuals. Moreover, the risk of atherosclerotic vascular abnormalities increased as BMD decreased. Future studies focusing on individuals with different severities of atherosclerosis and comorbidities are of interest.

Relationship between osteopenic syndrome and severity of coronary artery disease detected with coronary angiography and Gensini score in men

Background

Many studies have shown that evidence supporting the relationship between low bone mineral density (BMD) and coronary artery disease (CAD) has been increasing. There is a significant increase of myocardial infarction in men with low BMD.

Purpose

We aimed to detect the relationship between BMD and CAD in patients whose CAD was detected with coronary angiography, and its severity and prevalence was detected with Gensini score.

Methods

A total of 55 patients were selected who were found to have single or multiple infarctions through using coronary angiography in the cardiology clinic. The CAD severity was evaluated by calculating the Gensini score. These patients were divided into two groups: mild CAD and severe CAD groups. Femur bone mineral density (FBMD) was measured with dual energy X-ray absorptiometry. T score values were determined to be normal if the values were >−1.0 (n=22, 40%), and osteopenia–osteoporosis (osteopenic syndrome) if the T score values were ≤−1 (n=33, 60%).

Results

The FBMD of severe CAD according to the Gensini risk score was found to be significantly lower. FBMD values in patients decreased as their Gensini scores increased.

Conclusion

There was a significant relationship between CAD and osteopenic syndrome. FBMD level in men with severe CAD is significantly low when compared with patients who have mild CAD.

Abdominal aortic calcification: A reappraisal of epidemiological and pathophysiological data

In men and women, there is a significant association between the risk of cardiovascular event (myocardial infarction, stroke) and risk of major fragility fracture (hip, vertebra). Abdominal aortic calcification (AAC) can be assessed using semiquantitative scores on spine radiographs and spine scans obtained by DXA. Severe AAC is associated with higher risk of major cardiovascular event. Not only does severe AAC reflect poor cardiovascular health status, but also directly disturbs blood flow in the vascular system. Severe (but not mild or moderate) AAC is associated with lower bone mineral density (BMD), faster bone loss and higher risk of major fragility fracture. The fracture risk remains increased after adjustment for BMD and other potential risk factors. The association between severe AAC and fracture risk was found in both sexes, mainly in the follow-ups of less than 10years. Many factors contribute to initiation and progression of AAC: lifestyle, co-morbidities, inorganic ions, dyslipidemia, hormones, cytokines (e.g. inflammatory cytokines, RANKL), matrix vesicles, microRNAs, structural proteins (e.g. elastin), vitamin K-dependent proteins, and medications (e.g. vitamin K antagonists). Osteogenic transdifferentiation of vascular smooth muscle cells (VSMC) and circulating osteoprogenitors penetrating into vascular wall plays a major role in the AAC initiation and progression. Vitamin K-dependent proteins protect vascular tunica media against formation of calcified deposits (matrix GLA protein, GLA-rich protein) and against VSMC apoptosis (Gas6). Further studies are needed to investigate clinical utility of AAC for the assessment of fracture and cardiovascular risk at the individual level and develop new medications permitting to prevent AAC progression.

Decreased bone mineral density is associated with coronary atherosclerosis in healthy postmenopausal women

Objective

This study aimed to assess the association between bone mineral density (BMD) and coronary atherosclerosis in healthy postmenopausal women.

Methods

We performed a retrospective review of 252 postmenopausal women who had visited a health promotion center for a routine checkup. BMD of the lumbar spine (L1-L4) and femoral neck was evaluated using dual-energy X-ray absorptiometry, and coronary atherosclerosis was assessed using 64-row multidetector computed tomography. Participants were divided into normal BMD and osteopenia-osteoporosis groups, according to the T-scores of their lumbar spine or femoral neck.

Results

Participants with osteopenia-osteoporosis had a significantly higher proportion of coronary atherosclerosis than did those with normal BMD at the lumbar spine (P=0.003) and femoral neck (P=0.004). Osteopenia-osteoporosis at the lumbar spine (odds ratio [OR], 2.86; 95% confidence interval [CI], 1.12 to 7.27) or femoral neck (OR, 3.35; 95% CI, 1.07 to 10.57) was associated with coronary atherosclerosis, after controlling for age and cardiovascular risk factors.

Conclusion

Decreased BMD is associated with coronary atherosclerosis in healthy postmenopausal women, independent of age and cardiovascular risk factors. Postmenopausal women with decreased BMD may have a higher risk of developing coronary atherosclerosis.

Vitamin D deficiency plays an important role in cardiac disease and affects patient outcome: Still a myth or a fact that needs exploration?

There is increasing evidence that a low vitamin D status may be an important and hitherto neglected factor of cardiovascular disease. This review is an overview of the current body of literature, and presents evidence of the mechanisms through which vitamin D deficiency affects the cardiovascular system in general and the heart in particular. Available data indicate that the majority of congestive heart failure patients have 25-hydroxyvitamin D deficiency. Furthermore, the low serum 25-hydroxyvitamin D level has a higher impact on hypertension, coronary artery disease an on the occurrence of relevant cardiac events. A serum 25-hydroxyvitamin D level below 75 nmol/l (30 ng/l) is generally regarded as vitamin D insufficiency in both adults and children, while a level below 50 nmol/l (20 ng/l) is considered deficiency. Levels below 50 nmol/l (20 ng/l) are linked independently to cardiovascular morbidity and mortality.

Coronary microvascular endothelial dysfunction is an independent predictor of development of osteoporosis in postmenopausal women

BACKGROUND

A growing body of evidence links coronary artery atherosclerosis and calcification to osteoporosis in women. The endothelium plays a critical role in maintaining vascular integrity and may play a role in bone metabolism. We aimed to determine whether early coronary atherosclerosis, as detected by coronary microvascular endothelial dysfunction (CMED), predicts the development of osteoporosis in postmenopausal women.

METHODS

Coronary vascular reactivity was evaluated in 194 postmenopausal women greater than 50 years of age and with non-obstructive coronary arteries by administration of intracoronary acetylcholine during diagnostic angiography. CMED was defined as ≤50% increase in coronary blood flow from baseline in response to maximal dose. After a median follow-up of 7.0±0.3 years, patients were assessed by a questionnaire for development of osteoporosis.

RESULTS

The average age of the cohort was 60.9±7.4 years. Women with CMED were twice as likely to develop osteoporosis compared with women without endothelial dysfunction after adjustment for potential confounders (relative risk, 2.4; 95% confidence interval [CI], 1.1, 5.6, P=0.02). Epicardial endothelial dysfunction was not associated with development of osteoporosis.

DISCUSSION

Early coronary atherosclerosis with endothelial dysfunction is an independent marker for increased risk of developing osteoporosis in postmenopausal women greater than 50 years of age without obstructive coronary artery disease. The current study supports a link between coronary atherosclerosis and osteoporosis.

Bone mineral density, vertebral fractures and body mass index in postmenopausal women with abdominal aortic calcification

BACKGROUND

Evidence suggest that there are connections between osteoporosis and cardiovascular diseases.

OBJECTIVES

The aim of the study was to analyze the relationship between radiological measurements of abdominal aorta calcifications (AAC) and bone mineral density (BMD) in postmenopausal women.

METHODS

In this cross-sectional study were included 125 postmenopausal women 50-84 years of age. BMD of the spine and hip was measured by dual energy X-ray absorptiometry (DXA). AAC were assessed by lateral radiographs of lumbar spine (L1-L4), using the antero-posterior severity score (0-24). Vertebral fractures were evaluated from T4 to L4 using Genant's semiquantitative method.

RESULTS

Forty-one (32.8%) patients had osteoporosis and 61 (48.8%) had AAC with a mean score of 3.1. Postmenopausal women with AAC were older and had significantly lower femoral neck and trochanteric BMD than subjects without AAC (all p < 0.01). There were no significant differences in the frequency of fractures between subjects with AAC and those without AAC (p > 0.05). In univariate analysis, age, height, weight, femoral and trochanter BMD were significantly associated with the severity of AAC score. In multiple regression analysis, femoral neck BMD, but not lumbar spine, trochanter BMD or age, was an independent predictor of AAC.

CONCLUSIONS

Reduced femoral neck BMD is negatively associated with the presence of AAC in postmenopausal women. The association between BMD and AAC seems to be age-independent, which suggests a common pathogenesis for bone loss and vascular calcifications.

Metformin inhibits vascular calcification in female rat aortic smooth muscle cells via the AMPK-eNOS-NO pathway

Metformin exhibits diverse protective effects against diabetic complications, such as bone loss. Here, we investigated the effect of metformin on vascular calcification, another type 2 diabetes complication. In female rat aortic smooth muscle cells (RASMCs), we observed that metformin significantly alleviated β-glycerophosphate-induced Ca deposition and alkaline phosphatase activity, corresponding with reduced expression of some specific genes in osteoblast-like cells, including Runx2 and bone morphogenetic protein-2, and positive effects on α-actin expression, a specific marker of smooth muscle cells. Mechanistic analysis showed that phosphorylation levels of both AMP-activated protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS) were increased with NO overproduction. After inhibition of either AMPK or eNOS with the pharmacologic inhibitors, compound C or Nω-Nitro-L-arginine methyl ester, NO production was lowered and metformin-meditated vascular protection against β-glycerophosphate-induced Ca deposition was removed. Our results support that metformin prevents vascular calcification via AMPK-eNOS-NO pathway.

Association between circulating osteoblast progenitor cells and aortic calcifications in women with postmenopausal osteoporosis

BACKGROUND AND AIMS

Ectopic artery calcification has been documented in women with postmenopausal osteoporosis, in whom an imbalance in the number of circulating osteoprogenitor cells (OPCs) has been identified. Circulating OPCs form calcified nodules in vitro; however, it remains unknown whether an association exists between the number of circulating OPCs and aortic calcifications. We investigated the relationship between OPCs and aortic calcifications in women with postmenopausal osteoporosis.

METHODS AND RESULTS

The number of circulating OPCs was quantified by FACS analysis in 50 osteoporotic postmenopausal women. OPCs were defined as CD15-/alkaline-phosphatase(AP)+ cells coexpressing or not CD34. Participants underwent measurement of markers of bone metabolism, bone mineral density and abdominal aortic calcium (AAC) by 64-slice computed tomography. Patients with AAC were older, had lower 25(OH)vitamin D levels and higher circulating CD15-/AP+/CD34- cells than those without AAC. Significant correlates of AAC included age (rho = 0.38 p = 0.006), calcium (rho = 0.35 p = 0.01), 25(OH)vitamin D (rho = -0.31, p = 0.03) and the number of CD15-/AP+/CD34- cells (rho = 0.55 p < 0.001). In regression analyses, the log-transformed number of CD15-/AP+/CD34- cells was associated with the presence (OR = 6.45, 95% CI 1.03-40.1, p = 0.04) and severity (β = 0.43, p < 0.001) of AAC, independent of age, 25(OH)vitamin D, calcium and other potential confounders. Patients with low 25(OH)vitamin D and high CD15-/AP+/CD34- cells had higher median AAC than other patients (1927/μL, 862-2714/μL vs 147/μL, 0-1665/μL, p = 0.003).

CONCLUSION

In women with postmenopausal osteoporosis, the number of circulating CD15-/AP+/CD34- cells is significantly associated with increased aortic calcifications, that appear to be correlated also with reduced 25(OH)vitamin D levels.

Association between cardiovascular diseases and osteoporosis-reappraisal

Positive association between cardiovascular diseases and osteoporosis is important because it concerns two major public health problems. Men and women with cardiovascular diseases (including severe abdominal aortic calcification (AAC) and peripheral arterial disease) tend to have lower areal and volumetric bone mineral density (BMD) as well as faster bone loss, although findings vary according to skeletal site. On one hand, severe forms of cardiovascular diseases (heart failure, myocardial infarction, hypertension, severe AAC) are associated with higher risk of osteoporotic fracture, especially hip fracture. This link was found in the studies based on healthcare databases and the cohort studies. On the other hand, low BMD, history of fragility fracture, vitamin D deficit and increased bone resorption are associated with higher risk of major cardiovascular events (myocardial infraction, stroke, cardiovascular mortality). Moreover, osteocalcin secreted by osteoblasts may be involved in the regulation of energetic and cardiovascular metabolism. The association between both pathologies depends partially on the shared risk factors, and also on the mechanisms that are involved in the regulation of bone and cardiovascular metabolism. Interpretation of the data should take into account methodological limitations: representativeness of the cohorts, quality of the registers and the information obtained from questionnaires, severity of diseases, number of events (statistical power) and their temporal closeness, availability of the information on potential confounders. It seems that patients with severe form of osteoporosis would benefit from assessment of the cardiovascular status and vice versa. However, official guidelines for the clinical practice are still lacking.

Is vascular calcification associated with bone mineral density and osteoporotic fractures in ambulatory, elderly women?

We analyzed the relationship between aortic calcification and two osteoporotic parameters (bone mineral density (BMD) and incident osteoporotic fractures) in 667 ambulatory, elderly women from the Epidemiology of Osteoporosis (EPIDOS) cohort (mean age, 80 years; range, 72-94 years). We did not find any correlation between the aortic calcification score and BMD or osteoporotic fractures.

INTRODUCTION

The aging process is associated with osteoporosis and aortic calcification; conditions which may have similar disease mechanisms. However, the relationship between these two settings remains to be elucidated. We analyzed the relationship between aortic calcification and osteoporotic parameters (BMD and incident osteoporotic fractures) in a cohort of ambulatory, elderly women.

METHODS

The study included 667 ambulatory women from the EPIDOS cohort (mean age, 80 years; age range, 72-94 years). The baseline examination included bone investigations, a clinical and functional examination, and a comprehensive questionnaire on health status and lifestyle. Semiquantitative methods were used to determine the abdominal aortic calcification score on baseline radiographs. Incident fractures were recorded via postal questionnaires issued every 4 months for about 4 years.

RESULTS

Five hundred three women (75%) had aortic calcification. The mean aortic calcification score was 5.5 (median, 4). During the follow-up period, 186 (28%) women reported one or more incident osteoporotic fractures. We did not find any correlation between the aortic calcification score on one hand and the BMD or the occurrence of incident osteoporotic fractures on the other. Only age and systolic blood pressure were found to be independently associated with the aortic calcification score. Osteoporotic fractures were independently associated with age and BMD.

CONCLUSIONS

Osteoporosis and aortic calcification appear to be independent processes in a cohort of ambulatory, elderly women. However, potential confounding factors may be present and prospective studies are needed to investigate this situation further.

Arterial stiffening relates to arterial calcification but not to noncalcified atheroma in women. A twin study

OBJECTIVES

Our aim was to examine the relationship of arterial stiffness to measures of atherosclerosis, arterial calcification, and bone mineral density (BMD); the heritability of these measures; and the degree to which they are explained by common genetic influences.

BACKGROUND

Arterial stiffening relates to arterial calcification, but this association could result from coexistent atherosclerosis. A reciprocal relationship between arterial stiffening/calcification and BMD could explain the association between cardiovascular morbidity and osteoporosis.

METHODS

We examined, in 900 women from the Twins UK cohort, the relationship of carotid-femoral pulse wave velocity (cfPWV) to measures of atherosclerosis (carotid intima-media thickening; carotid/femoral plaque), calcification (calcified plaque [CP]; aortic calcification by computed tomography, performed in subsample of 40 age-matched women with low and high cfPWV), and BMD.

RESULTS

The cfPWV independently correlated with CP but not with intima-media thickness or noncalcified plaque. Total aortic calcium, determined by computed tomography, was significantly greater in subjects with high cfPWV (median Agatston score 450.4 compared with 63.2 arbitrary units in subjects with low cfPWV, p = 0.001). There was no independent association between cfPWV and BMD. Adjusted heritability estimates of cfPWV and CP were 0.38 (95% confidence interval: 0.19 to 0.59) and 0.61 (95% confidence interval: 0.04 to 0.83), respectively. Shared genetic factors accounted for 92% of the observed correlation (0.38) between cfPWV and CP.

CONCLUSIONS

These results suggest that the association between increased arterial stiffness and the propensity of the arterial wall to calcify is explained by a common genetic etiology and is independent of noncalcified atheromatous plaque and independent of BMD.

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.

Relationships between vascular calcification, calcium metabolism, bone density, and fractures

Factors involved with calcium metabolism, such as serum calcium and phosphate and calcium intake, have been associated with vascular disease in different populations. We investigated whether this association is mediated via increased vascular calcification by assessing relationships between these factors and abdominal aortic calcification (AAC) and coronary artery calcification (CAC). A total of 1471 healthy postmenopausal women participated in a 5-year randomized, placebo-controlled trial of calcium 1 g/day, and 323 healthy middle-aged and older men participated in a 2-year randomized, placebo-controlled trial of calcium 600 or 1200 mg/day. AAC was assessed on vertebral morphometric images at baseline and follow-up. Based on computed tomography, 163 men had CAC assessed, on average, 1.5 years after study completion. In elderly women, AAC was positively related to serum calcium (p < .001), phosphate (p = .04), and the calcium-phosphate product (p = .003), but changes in AAC over time and incidence of cardiovascular events were not related to these variables. In middle-aged men, AAC and CAC were not consistently related to these variables. Neither dietary calcium intake nor calcium supplementation was associated with changes in the prevalence of AAC over time, and calcium supplementation also was not related to CAC scores in men. After adjusting for age, AAC was not associated with low bone mineral density (BMD) at baseline, changes in BMD over time, or fracture incidence. CAC also was not related to baseline BMD. In summary, serum calcium and phosphate are associated with AAC in older women, but dietary calcium intake and calcium supplementation were not associated with changes in AAC over 2 to 5 years.

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.

Vascular calcification and bone disease: the calcification paradox

Vascular calcification or ectopic mineralization in blood vessels is an active, cell-regulated process, increasingly recognized as a general cardiovascular risk factor. Remarkably, ectopic artery mineralization is frequently accompanied by decreased bone mineral density or disturbed bone turnover. This contradictory association, observed mainly in osteoporosis and chronic kidney disease, is called the 'calcification paradox'. Here, we review recent advances in our understanding of the calcification paradox, including protein expression patterns governing both normal and ectopic mineralization, the conversion of vascular smooth muscle cells to bone-like cells, and the regulatory pathways involved in both bone and vessel mineralization. Further elucidation of the mechanisms underlying the calcification paradox is crucial in order to develop preventive and therapeutic strategies to deal with vascular calcification and reduce the associated cardiovascular risk.

Abdominal aortic calcification, BMD, and bone microstructure: a population-based study

To better define the relationship between vascular calcification and bone mass/structure, we assessed abdominal aortic calcification (AAC), BMD, and bone microstructure in an age-stratified, random sample of 693 Rochester, MN, residents. Participants underwent QCT of the spine and hip and high-resolution pQCT (HRpQCT) of the radius to define volumetric BMD (vBMD) and microstructural parameters. AAC was quantified with the Agatston scoring method. In men, AAC correlated with lower vertebral trabecular and femoral neck vBMD (p < 0.001), but not after age or multivariable (age, body mass index, smoking status) adjustment. Separation into <50 and >or=50 yr showed this pattern only in the older men. BV/TV and Tb.Th inversely correlated with AAC in all men (p < 0.001), and Tb.Th remained significantly correlated after age adjustment (p < 0.05). Tb.N positively correlated with AAC in younger men (p < 0.001) but negatively correlated in older men (p < 0.001). The opposite was true with Tb.Sp (p = 0.01 and p < 0.001, respectively). Lower Tb.N and higher Tb.Sp correlated with AAC in older men even after multivariable adjustment. Among all women and postmenopausal women, AAC correlated with lower vertebral and femoral neck vBMD (p < 0.001) but not after adjustment. Lower BV/TV and Tb.Th correlated with AAC (p = 0.03 and p = 0.04, respectively) in women, but not after adjustment. Our findings support an age-dependent association between AAC and vBMD. We also found that AAC correlates with specific bone microstructural parameters in older men, suggesting a possible common pathogenesis for vascular calcification and deterioration in bone structure. However, sex-specific differences exist.

Progression of vascular calcifications is associated with greater bone loss and increased bone fractures

In this prospective study, we found a positive relationship between the prevalence of aortic calcifications and age. Aortic calcifications at baseline were positively associated with osteoporotic fractures. In addition, progression of aortic calcifications was also positively associated with the rate of decline in BMD at lumbar spine.

INTRODUCTION

The aim of this study was to analyze the relationship between the progression of abdominal aortic calcification and osteoporosis in a Spanish cohort of men and women older than 50.

METHODS

Men and women (n=624) aged 50 and over underwent two lateral X-rays of thoracic and lumbar spine and a dual X-ray absorptiometry (DXA) study at lumbar spine and hip, and were followed during 4 years. Abdominal aortic calcifications were classified as absent, mild-moderate and severe.

RESULTS

There was a positive relationship between the prevalence of aortic calcifications and age. In both sexes, prevalent severe aortic calcifications were positively associated with prevalent osteoporotic fractures [odds ratio (OR)=1.93 (1.02-3.65)]. The association was stronger when only vertebral fracture was considered [OR=2.45 (1.23-4.87)]. In addition, progression of aortic calcifications showed a positive association with the rate of decline in bone mineral density (BMD) at lumbar spine.

CONCLUSIONS

Aortic calcifications at baseline were positively associated with osteoporotic fractures. The progression of aortic calcifications was also positively associated with the rate of decline in BMD at lumbar spine.

Vitamin D and cardiovascular disease risk

PURPOSE OF REVIEW

Despite our understanding of how to prevent and treat traditional cardiovascular risk factors, cardiovascular disease remains the leading cause of death of both men and women in the US. Thus, there is widespread interest in a number of emerging nontraditional risk factors for the detection of early cardiovascular disease in order to implement aggressive preventive therapies. 25-Hydroxyvitamin D deficiency has been identified as a potential novel cardiovascular disease risk factor. This review outlines what is known about the association of 25-hydroxyvitamin D levels and cardiovascular disease risk.

RECENT FINDINGS

Low 25-hydroxyvitamin D levels have been associated with the cardiovascular disease risk factors of hypertension, obesity, diabetes mellitus and the metabolic syndrome, as well as cardiovascular disease events including stroke and congestive heart failure. Studies suggest vitamin D deficiency may be a contributor to the development of cardiovascular disease potentially through associations with diabetes or hypertension.

SUMMARY

Vitamin D deficiency is easy to screen for and easy to treat with supplementation. Further larger observational studies and randomized clinical trials are, however, needed to determine whether vitamin D supplementation could have any potential benefit in reducing future cardiovascular disease events and mortality risk.

Association of high alpha2-Heremans–Schmid glycoprotein/fetuin concentration in serum and intima-media thickness in patients with atherosclerotic vascular disease and low bone mass

OBJECTIVE

Alpha2-Heremans-Schmid glycoprotein (AHSG; fetuin), a member of the cystatin superfamily of cysteine protease inhibitors involved in vascular pathology and bone metabolism, has been reported to be reduced in patients with atherosclerosis and medial calcification related to end stage renal disease or dialysis. No data on fetuin in patients with peripheral artery disease associated with low bone mass and normal renal function are available in the literature. In the present study we evaluated serum fetuin concentrations, bone mass, and markers of bone turnover in patients with atherosclerosis of peripheral vessels and normal kidney function.

PATIENTS AND METHODS

Ninety consecutive patients with evidence of atherosclerotic plaques at the common carotid or femoral artery were studied. Severity grade of disease was documented by ultrasound measurement of intima-media thickness (IMT). Fasting serum levels of fetuin were measured by sandwich enzyme immunoassay.

MAIN RESULTS

The mean patient serum concentration of fetuin was 57.68+/-13.6 ng/ml, significantly higher than that of control subjects (41.6+/-7.6 ng/ml; p<0.001). The mean serum concentration of bone-specific alkaline phosphatase (BAP) were 8.4+/-2.3 microg/l, significantly lower than controls (13.6+/-1.6 microg/l; p<0.001). Fetuin was correlated with IMT (r=0.8530; p<0.0001) and inversely correlated with BAP (r=-0.5503; p<0.0001). Patients had a vertebral and femoral bone mass significantly lower than controls.

CONCLUSION

This study documented for the first time that, in patients with atherosclerosis of peripheral vessels, serum fetuin levels were higher than in healthy subjects, and correlated with the severity of disease; further studies are required to analyse the role of AHSG as an independent predictor of atherosclerotic disease and low bone mass in patients with normal renal function.

Association between systemic calcified atherosclerosis and bone density

Both atherosclerosis and osteoporosis are responsible for significant morbidity and mortality, are independent predictors of cardiovascular disease (CVD) events, and may share common regulatory mechanisms as well as histopathology. Multiple reports of weak or null relationships between traditional CVD risk factors and calcified atherosclerosis have heightened interest in novel predictors of arterial calcium. One such hypothesis is for an inverse relationship between bone mineral density (BMD) and calcified coronary atherosclerosis. Although contrary findings have been reported, the majority of cross-sectional and all prospective studies have demonstrated a significant inverse association between arterial calcium deposits and BMD. The few studies that include men are equivocal, and, to date, no study has investigated the relationship between BMD and systemic arterial calcium. The aim of this study was to test the hypothesis that lumbar BMD is significantly associated with the presence of arterial atherosclerotic calcium in the carotid, coronary, and iliac vascular beds as well as the aorta.

Relationship between vascular calcification and bone mineral density in the Old-order Amish

Vascular calcification and osteoporosis are common age-related processes that are influenced by both genetic and nongenetic factors. Whether common genes underlie these processes is not known. We measured coronary artery calcification (CAC), aortic calcification (AC), and bone mineral density (BMD) in 682 men and women from large Old-Order Amish families. We assessed the heritabilities of these traits and then evaluated, using variance decomposition procedures, whether variation in the traits was influenced by a common set of genes (i.e., pleiotropy). Significant heritabilities were detected for BMD of the femoral neck and spine (0.65, 0.63) and CAC and AC (0.43, 0.42). Mean BMD did not differ significantly across quartiles of either CAC or AC in either sex. In neither the total group nor any single subgroup (men, women, postmenopausal women) did any of the genetic or environmental correlations between BMD and vascular calcification achieve statistical significance. However, subjects with a history of cardiovascular disease (CVD) events had significantly lower BMD at the femoral neck compared to subjects who reported no prior history of CVD (age-, sex-, body mass index-, and family structure-adjusted P = 0.003). We detected no evidence for shared genes affecting the joint distribution of bone and vascular calcification. However, our results do reveal a lower BMD in subjects with a prior history of CVD in the Old-Order Amish.

Interaction of vascular and bone disease in patients with normal renal function and patients undergoing dialysis

The cardiovascular risk of patients undergoing dialysis is 20-30 times higher than that of individuals of the same age, without abnormal renal function, from the general population. Observational studies of patients with normal and abnormal renal function have shown that there is an association between bone disease, vascular calcification and cardiovascular outcome and that worsening of these conditions happens in parallel. Basic science studies are elucidating several mechanisms that could explain the interaction between bone disease, vascular calcification and cardiovascular outcome. For example, the expression of osteoprotegerin-a protein that regulates bone resorption by binding receptor activator of nuclear factor kappaB (RANK) ligand (RANKL), thus preventing interaction with the receptor RANK and the stimulation of osteoclast maturation-is regulated by several cytokines. Additionally, osteoprotegerin seems involved in the genesis of atherosclerosis. Imbalances of bone mineral metabolism, bone matrix secretion and vascular smooth-muscle-cell apoptosis seem involved in the ossification of the arterial wall in chronic kidney disease, and could explain some of the complex interactions between bone and vascular disease in renal failure. In this article we present a brief review of some of the basic mechanisms involved in vascular calcification and the clinical evidence of an association of vascular and bone disease.

Volumetric BMD and vascular calcification in middle-aged women: the Study of Women's Health Across the Nation

The association of spine vBMD with AC and CAC was studied in a biracial cohort of 490 middle-aged women in the Study of Women's Health Across the Nation. Lower vBMD was related to high AC, but not to CAC, independent of age and shared risk factors between osteoporosis and cardiovascular disease.

INTRODUCTION

This analysis studied the association of spine volumetric BMD (vBMD) with aortic (AC) and coronary artery (CAC) calcification in middle-aged women and evaluated whether such associations were independent of age and shared risk factors between osteoporosis and cardiovascular disease (CVD) or explained by endogenous estradiol levels.

MATERIALS AND METHODS

Vascular calcification and trabecular vBMD of the spine were measured using electron-beam CT in 490 women free from clinical CVD in the Study of Women's Health Across the Nation. Women were 45-58 years of age, 61% were white, and 64% were perimenopausal. Calcification scores were categorized into three levels (no AC, N = 146; moderate AC, scores = 1-74, N = 221; high AC, N = 123; no CAC, N = 256; moderate CAC, score = 1-7.54, N = 111; high CAC, N = 123). The highest categories were set at the 75th percentiles. Multinomial logistic regression was used to assess the association between vBMD (per SD) and the AC and CAC levels, with no calcification as the reference group.

RESULTS

AC and CAC were detected in 70% and 48% of the population, respectively. Mean vBMD was 161.6 +/- 37.2 (SD) mg/ml. vBMD was associated with high AC in unadjusted, age-adjusted, and risk factor-adjusted analysis. Per 1 SD decrease in vBMD, the adjusted odds of high AC compared with no AC was significantly increased by 68% (95% CI, 1.06-2.68). Estradiol did not influence this association. vBMD was related to high CAC in unadjusted (OR = 1.35; 95% CI, 1.08-1.70) but not adjusted models. No associations of vBMD with moderate AC or CAC were observed.

CONCLUSION

Lower vBMD was related to high AC, but not to CAC, in a biracial cohort of healthy middle-aged women independent of age and shared risk factors between osteoporosis and CVD. Further research should study possible pathophysiological links between the two conditions and the potential for common preventive and therapeutic interventions.

Paraoxonase-1 activity as a marker of atherosclerosis is not associated with low bone mineral density in healthy postmenopausal women

The aging process is associated with an increasing prevalence of osteoporosis and atherosclerosis, but it is uncertain if these two conditions are interrelated. Serum paraoxonase-1 (PON1) is a high-density lipoprotein (HDL) associated enzyme that has been implicated in the pathogenesis of atherosclerosis. Our aims of the study were to investigate (1) serum paraoxonase and arylesterase activities and, lipid hydroperoxide (LOOH) levels in healthy postmenopausal women and (2) whether there were any associations between these enzyme activities and bone mineral density (BMD). A total of 97 generally healthy postmenopausal women were enrolled in the study. BMD was measured at lumbar spine (LS) and femoral neck (FN) with dual energy X-ray absorptiometry. Serum paraoxonase and arylesterase activities were measured spectrophotometrically. LOOH levels were measured by iodometric assay. In this population, 50 (51%) women had BMD T scores < -2.5 at the LS and/or FN defined as osteoporosis and 47 (49%) of them had normal BMDs. Serum paraoxonase, arylesterase, and LOOH activities were not significantly different between osteoporotic and nonosteoporotic postmenopausal women. There were also no correlations between paraoxonase, arylesterase, LOOH activities, and LS BMD and FN BMD. We conclude that there may be not good evidence to support a direct relationship between osteoporosis and atherosclerosis in these subjects. However, prospective studies with larger groups are needed to investigate this issue further.

Carotid plaque echogenicity and risk of nonvertebral fractures in women: a longitudinal population-based study

Atherosclerosis and osteoporosis appear to be related, but prospective studies on the relationship are sparse. In order to examine whether carotid artery plaques with different morphology predict nonvertebral fractures, we followed 2,733 women, aged 55-74 years (75% of the eligible population in Tromsø, Norway), for 6 years. At baseline, plaque morphology in terms of ultrasound echogenicity was categorized into three groups, ranging from low echogenicity (echolucent plaques with a high content of soft tissue) to strong echogenicity (echogenic plaques with a high content of dense fibrous tissue and calcified material). We found that the age-adjusted relative risk (RR) of fracture was significantly higher among women with echogenic plaques than among women without plaques: 1.7 (95% confidence interval [CI] 1.0-2.7). After adjustment for bone mineral density at baseline in addition to age, the RR was 1.6 (95% CI 1.0-2.6), and further adjustments for body mass index, body height, high-density lipoprotein cholesterol, smoking status, and muscle strength did not influence the association. Subjects with other plaque types were not at an increased risk compared to subjects without plaques: RR < or = 1.1, after multiple adjustments. We conclude that in the general population elderly women with echogenic carotid plaques are at higher risk of nonvertebral fractures than women without plaques.

Postmenopausal osteoporosis and atheroma

Epidemiological studies have established a significant association between two major health problems, osteoporosis and atheroma, which is independent from age, gender, and other cardiovascular risk factors. Bone loss and the development of calcific deposits within vessel walls occur concomitantly. Proteins formerly thought to be specific of bone have been identified in atheroma lesions; and associations linking vertebral and proximal femoral fractures to aortic calcifications have been reported. Bone loss may be a marker for the risk of stroke and cardiovascular death. Bone loss may occur as a consequence of ischemia related to vascular disease. Despite numerous published studies, the mechanism underlying the osteoporosis-atheroma association remains controversial. Factors that perpetuate the debate include the often retrospective design of the studies, small sample sizes, and known limitations of absorptiometry as a tool for measuring osteoporosis severity. We reviewed the available clinical, epidemiological, and animal data on the mechanisms underlying the association between osteoporosis and atheroma. The possible effect of osteoporosis medications on the blood vessel wall is discussed. These issues remain a matter of debate, indicating a need for vast prospective studies to look for a causal link between osteoporosis and atheroma. The results of these studies may lead to new treatment strategies.

Volumetric and areal bone mineral density measures are associated with cardiovascular disease in older men and women: the health, aging, and body composition study

The associations of volumetric (vBMD) and areal (aBMD) bone mineral density measures with prevalent cardiovascular disease (CVD) and subclinical peripheral arterial disease (PAD) were investigated in a cohort of older men and women enrolled in the Health, Aging, and Body Composition Study. Participants were 3,075 well-functioning white and black men and women (42% black, 51% women), aged 68-80 years. Total hip, femoral neck, and trochanter aBMD were measured using dual-energy X-ray absorptiometry. Quantitative computed tomography was used to evaluate spine trabecular, integral, and cortical vBMD measures in a subgroup (n = 1,489). Logistic regression was performed to examine associations of BMD measures with CVD and PAD. The prevalence of CVD (defined by coronary heart disease, PAD, cerebrovascular disease, or congestive heart failure) was 29.8%. Among participants without CVD, 10% had subclinical PAD (defined as ankle-arm index <0.9). Spine vBMD measures were inversely associated with CVD in men (odds ratio of integral [OR(integral)] = 1.34, 95% confidence interval [CI] 1.10-1.63; OR(trabecular )= 1.25, 95% CI 1.02-1.53; OR(cortical )= 1.36, 95% CI 1.11-1.65). In women, for each standard deviation decrease in integral vBMD, cortical vBMD, or trochanter aBMD, the odds of CVD were significantly increased by 28%, 27%, and 22%, respectively. Total hip aBMD was associated with subclinical PAD in men (OR = 1.39, 95% CI 1.03-1.84) but not in women. All associations were independent of age and shared risk factors between BMD and CVD and were not influenced by inflammatory cytokines (interleukin-6 and tumor necrosis factors-alpha). In conclusion, our results provide further evidence for an inverse association between BMD and CVD in men and women. Future research should investigate common pathophysiological links for osteoporosis and CVD.

Coronary calcification and osteoporosis in men and postmenopausal women are independent processes associated with aging

The objective of this study was to investigate whether low bone mass is directly associated with the severity of coronary atherosclerosis in men and postmenopausal women self-referred for evaluation of coronary atherosclerosis and osteoporosis. Low bone mass was evaluated by measurement of bone mineral density (BMD) using quantitative computerized tomography (QCT). Coronary atherosclerosis was evaluated by measurement of coronary calcium (CC) burden using electron beam computerized tomography (EBCT). Using a cross-sectional design, we tested the hypothesis that osteoporosis and coronary atherosclerosis are correlated, age-dependent processes. Study variables were BMD, CC scores, and other known risk factors for osteoporosis and atherosclerosis. Qualifying for the study were 313 postmenopausal women and 167 men. Men had higher baseline CC scores and higher body mass indexes compared to women. In females, those patients with coronary calcification were older and had significantly lower BMD compared to those without calcification. In males, those patients with coronary calcification were older. By univariate correlation analysis, the degree of coronary calcification was inversely associated with BMD in postmenopausal women (P < 0.0001) but not in men. However, after controlling for age, this association was absent for both men and postmenopausal women. Using multivariate logistic regression analysis in women and men separately, age was the only significant predictor of positive CC status and low BMD. Our study suggests that in postmenopausal women and in men, after controlling for age, osteoporosis and coronary atherosclerosis are independent processes.

Increased prevalence of peripheral arterial disease in osteoporotic postmenopausal women

The aim of this study was to investigate the prevalence and correlates of peripheral arterial disease (PAD) in a population of osteoporotic postmenopausal women. The presence of PAD was assessed by ankle brachial index (ABI) in 345 ambulatory osteoporotic postmenopausal women, and in 360 community-based, age- and race-matched postmenopausal women with normal bone mineral density (BMD) (control group). PAD was detected in 63/345 (18.2%) osteoporotic women and in 14/360 (3.8%) control subjects (P < 0.0001). The mean ABI values were significantly lower in the osteoporosis group than in the control group (0.98 +/- 0.09 vs. 1.04 +/- 0.06, P < 0.0001). No difference in cardiovascular risk factors was observed between osteoporotic patients and controls, or between osteoporotic patients with and without PAD. Osteoporotic patients with PAD had lower femoral neck BMD T scores than those without PAD (-4.2 +/- 0.7 vs. -2.3 +/- 0.7, P < 0.0001). Only 4 PAD patients (5.1%) had intermittent claudication. In multivariate logistic regression analysis, factors independently associated with PAD within osteoporotic patients were lower femoral neck BMD T score (odds ratio (OR) = 0.20, 95% confidence interval (CI), 0.05-0.70, P = 0.01) and systolic blood pressure (OR = 1.02, 95% CI, 1.00-1.03, P = 0.01). This study shows for the first time an increased prevalence of PAD among osteoporotic postmenopausal women, with a lower femoral neck BMD T score being a significant independent predictor. The findings suggest that vascular status evaluation should be done in osteoporotic postmenopausal women in order to identify candidate patients for preventive and therapeutic cardiovascular interventions.

Relationship between bone mineral density and myocardial infarction in US adults

Cardiovascular disease and osteoporosis have several common risk factors, and quite a few studies suggest a relationship between them. The objective of the present study was to explore the relationship between cardiovascular disease risk factors and bone mineral density in association with having had a previous myocardial infarction in a general population. This cross-sectional study was conducted using data for 5,050 women and men aged 50-79 years who participated in the Third National Health and Nutrition Examination Survey (NHANES III). Race/ethnic and gender-specific mean BMD values for young adults were used to determine race/ethnic and gender-specific T-scores to define osteoporosis and low BMD. Multiple logistic regression analysis revealed that subjects self-reporting a previous myocardial infarction had significantly higher odds (odds ratio 1.28, [95% confidence interval (CI), 1.01 to 1.63] p=0.04) of having low bone mineral density, when adjusting for cardiovascular disease and osteoporosis risk factors. Self-reported myocardial infarction was not significantly associated with low bone mineral density in women, (odds ratio 1.22, [95% CI, 0.80 to 1.86] p=0.37), but was significant in men, (odds ratio 1.39, [95% CI, 1.03 to 1.87] p=0.03). These findings demonstrate that male survivors of myocardial infarction have low bone mineral density. The pathophysiologic connection between the atherosclerotic and the osteoporotic processes needs further elucidation. It is also of importance to study the processes in both men and women.