Bone Mineral Density Is Negatively Associated With Arterial Stiffness in Men With Hypertension

Vascular function and skeletal fragility: a study of tonometry, brachial hemodynamics, and bone microarchitecture

Osteoporosis and cardiovascular disease frequently occur together in older adults; however, a causal relationship between these 2 common conditions has not been established. By the time clinical cardiovascular disease develops, it is often too late to test whether vascular dysfunction developed before or after the onset of osteoporosis. Therefore, we assessed the association of vascular function, measured by tonometry and brachial hemodynamic testing, with bone density, microarchitecture, and strength, measured by HR-pQCT, in 1391 individuals in the Framingham Heart Study. We hypothesized that decreased vascular function (pulse wave velocity, primary pressure wave, brachial pulse pressure, baseline flow amplitude, and brachial flow velocity) contributes to deficits in bone density, microarchitecture and strength, particularly in cortical bone, which is less protected from excessive blood flow pulsatility than the trabecular compartment. We found that individuals with increased carotid-femoral pulse wave velocity had lower cortical volumetric bone mineral density (tibia: -0.21 [-0.26, -0.15] standardized beta [95% CI], radius: -0.20 [-0.26, -0.15]), lower cortical thickness (tibia: -0.09 [-0.15, -0.04], radius: -0.07 [-0.12, -0.01]) and increased cortical porosity (tibia: 0.20 [0.15, 0.25], radius: 0.21 [0.15, 0.27]). However, these associations did not persist after adjustment for age, sex, height, and weight. These results suggest that vascular dysfunction with aging may not be an etiologic mechanism that contributes to the co-occurrence of osteoporosis and cardiovascular disease in older adults. Further study employing longitudinal measures of HR-pQCT parameters is needed to fully elucidate the link between vascular function and bone health.

Arterial stiffness and risk of new-onset fragility fracture in Chinese men and women: The Kailuan cohort study

BACKGROUND

Previous studies have shown an association between increased arterial stiffness and reduced bone mineral density. However, the relationship between arterial stiffness and fragility fracture remains unclear. In this study, we explored the impact of arterial stiffness on the risk of new-onset fragility fracture.

METHODS

The study included 53,107 participants in the Kailuan Study in whom brachial-ankle pulse wave velocity (baPWV) measurements were obtained between 2010 and 2021. All participants were free of fragility fractures at baseline. A Cox proportional hazard regression model was used to estimate the hazard ratio (HR) and 95 % confidence interval (CI) for incident fragility fracture on the baseline baPWV groups: <1400 cm/s (reference), 1400 ≤ baPWV < 1800 cm/s, and ≥1800 cm/s.

RESULTS

In total, 327 incident fragility fractures were recorded during an average follow-up of 4.99 ± 3.02 years. After adjustment for potential confounders, the HR for the risk of new-onset fragility fracture was 1.66 (95 % CI 1.14-2.42) for the arterial stiffness group in comparison with the normal baPWV group. The risk of fragility fracture was higher in men (HR 1.64, 95 % CI 1.05-2.57). There was a linear association between higher baPWV and fragility fracture.

CONCLUSIONS

Arterial stiffness as measured by baPWV was associated with the risk of fragility fracture.

Clinical Impact and Mechanisms of Nonatherosclerotic Vascular Aging: The New Kid to Be Blocked

Ischemic cardiovascular disease and stroke remain the leading cause of global morbidity and mortality. During aging, protective mechanisms in the body gradually deteriorate, resulting in functional, structural, and morphologic changes that affect the vascular system. Because atherosclerotic plaques are not always present along with these alterations, we refer to this kind of vascular aging as nonatherosclerotic vascular aging (NAVA). To maintain proper vascular function during NAVA, it is important to preserve intracellular signalling, prevent inflammation, and block the development of senescent cells. Pharmacologic interventions targeting these components are potential therapeutic approaches for NAVA, with a particular emphasis on inflammation and senescence. This review provides an overview of the pathophysiology of vascular aging and explores potential pharmacotherapies that can improve the function of aged vasculature, focusing on NAVA.

Tissue-specific expression of senescence biomarkers in spontaneously hypertensive rats: evidence of premature aging in hypertension

Background

Cellular senescence is an age-related physiological process that contributes to tissue dysfunction and accelerated onset of chronic metabolic diseases including hypertension. Indeed, elevation of blood pressure in hypertension coincides with premature vascular aging and dysfunction. In addition, onsets of metabolic disturbance and osteopenia in patients with hypertension have also been reported. It is possible that hypertension enhances premature aging and causes progressive loss of function in multiple organs. However, the landscape of cellular senescence in critical tissues affected by hypertension remains elusive.

Materials and Methods

Heart, liver, bone, hypothalamus, and kidney were collected from spontaneously hypertensive rats (SHR) and age- and sex-matched normotensive Wistar rats (WT) at 6, 12, 24 and 36 weeks of age (n = 10 animals/group). Changes in mRNA levels of senescence biomarkers namely cyclin-dependent kinase (CDK) inhibitors (CDKIs), i.e., Cdkn2a (encoding p16Ink4a) and Cdkn1a (encoding p21cip1) as well as senescence-associated secretory phenotypes (SASPs), i.e., Timp1, Mmp12, Il6 and Cxcl1, were determined. Additionally, bone collagen alignment and hydroxy apatite crystal dimensions were determined by synchrotron radiation small- and wide-angle X-ray scattering (SAXS/WAXS) techniques.

Results

Real-time PCR revealed that transcript levels of genes encoding CDKIs and SASPs in the heart and liver were upregulated in SHR from 6 to 36 weeks of age. Expression of Timp1 and Cxcl1 was increased in bone tissues isolated from 36-week-old SHR. In contrast, we found that expression levels of Timp1 and Il6 mRNA were decreased in hypothalamus and kidney of SHR in all age groups. Simultaneous SAXS/WAXS analysis also revealed misalignment of bone collagen fibers in SHR as compared to WT.

Conclusion

Premature aging was identified in an organ directly affected by high blood pressure (i.e., heart) and those with known functional defects in SHR (i.e., liver and bone). Cellular senescence was not evident in organs with autoregulation of blood pressure (i.e., brain and kidney). Our study suggested that cellular senescence is induced by persistently elevated blood pressure and in part, leading to organ dysfunction. Therefore, interventions that can both lower blood pressure and prevent cellular senescence should provide therapeutic benefits for treatment of cardiovascular and metabolic consequences.

Differential effects of dexamethasone on arterial stiffness, myocardial remodeling and blood pressure between normotensive and spontaneously hypertensive rats

Dexamethasone (DEX)-induced hypertension is observed in normotensive rats, but little is known about the effects of DEX on spontaneously hypertensive animals (SHR). This study aimed to evaluate the effects of DEX on hemodynamics, cardiac hypertrophy and arterial stiffness in normotensive and hypertensive rats. Wistar rats and SHR were treated with DEX (50 μg/kg s.c., 14 d) or saline. Pulse wave velocity (PWV), echocardiographic parameters, blood pressure (BP), autonomic modulation and histological analyses of heart and thoracic aorta were performed. SHR had higher BP compared with Wistar, associated with autonomic unbalance to the heart. Echocardiographic changes in SHR (vs. Wistar) were suggestive of cardiac remodeling: higher relative wall thickness (RWT, +28%) and left ventricle mass index (LVMI, +26%) and lower left ventricle systolic diameter (LVSD, -19%) and LV diastolic diameter (LVDD, -10%), with slightly systolic dysfunction and preserved diastolic dysfunction. Also, SHR had lower myocardial capillary density and similar collagen deposition area. PWV was higher in SHR due to higher aortic collagen deposition. DEX-treated Wistar rats presented higher BP (~23%) and autonomic unbalance. DEX did not change cardiac structure in Wistar, but PWV (+21%) and aortic collagen deposition area (+21%) were higher compared with control. On the other side, DEX did not change BP or autonomic balance to the heart in SHR, but reduced RWT and LV collagen deposition area (-12% vs. SHR_CT ). In conclusion, the results suggest a differential effect of dexamethasone on arterial stiffness, myocardial remodeling and blood pressure between normotensive and spontaneously hypertensive rats.

[The role of therapeutic exercises in blood pressure correction, vascular wall stiffness and disorders of bone and mineral metabolism in postmenopausal hypertensive patients]

OBJECTIVE

To study the role of therapeutic exercises (TE) in the correction of blood pressure, stiffness of the vascular wall and disorders of bone mineral metabolism in postmenopausal hypertensive patients.

MATERIAL AND METHODS

The study included 78 patients (mean age was 53.32±7.61 years). All patients are divided into 3 groups. The first control group is 20 women without arterial hypertension and menopause. The second group consisted of 27 patients with arterial hypertension (AH) and post-menopause who were not undergone the TE complex and the 3^rd group - 31 women with AH and post-menopause who were undergone TE complex. Patients of all groups were examined in dynamics: at the starting point of the study and 12 months later, out-patient monitoring of blood pressure; sphygmography; densitometry and test for blood serum biochemistry parameters, including sex hormones, vitamin D.

RESULTS

In the course of the study, blood pressure, vascular wall stiffness and disorder of bone mineral density were revealed significantly higher in the group 3 with significantly reduced levels of sex hormones. Multidirectional correlation relationships between the studied parameters are revealed. Treatment combined with therapeutic exercises led to permanent improvement tendency in studied parameters like blood pressure, pulse wave velocity, metabolic disorders and T-criterion.

CONCLUSION

The result of the study indicates that the exercise therapy complex used in the form of regular classes, according to the scheme proposed by the exercise therapy doctor, can be recommended for implementation in clinical practice with the aim of comprehensively affecting the patient's body and developing personalized treatment tactics for postmenopausal women with hypertension.

Poor Bone Quality is Associated With Greater Arterial Stiffness: Insights From the UK Biobank

Osteoporosis and ischemic heart disease (IHD) represent important public health problems. Existing research suggests an association between the two conditions beyond that attributable to shared risk factors, with a potentially causal relationship. In this study, we tested the association of bone speed of sound (SOS) from quantitative heel ultrasound with (i) measures of arterial compliance from cardiovascular magnetic resonance (aortic distensibility [AD]); (ii) finger photoplethysmography (arterial stiffness index [ASI]); and (iii) incident myocardial infarction and IHD mortality in the UK Biobank cohort. We considered the potential mediating effect of a range of blood biomarkers and cardiometabolic morbidities and evaluated differential relationships by sex, menopause status, smoking, diabetes, and obesity. Furthermore, we considered whether associations with arterial compliance explained association of SOS with ischemic cardiovascular outcomes. Higher SOS was associated with lower arterial compliance by both ASI and AD for both men and women. The relationship was most consistent with ASI, likely relating to larger sample size available for this variable (n = 159,542 versus n = 18,229). There was no clear evidence of differential relationship by menopause, smoking, diabetes, or body mass index (BMI). Blood biomarkers appeared important in mediating the association for both men and women, but with different directions of effect and did not fully explain the observed effects. In fully adjusted models, higher SOS was associated with significantly lower IHD mortality in men, but less robustly in women. The association of SOS with ASI did not explain this observation. In conclusion, our findings support a positive association between bone and vascular health with consistent patterns of association in men and women. The underlying mechanisms are complex and appear to vary by sex. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Unraveling the Links Underlying Arterial Stiffness, Bone Demineralization, and Muscle Loss

The effects of elevated arterial stiffness on cardiovascular outcomes are widely studied, whereas the relation to noncardiovascular outcomes relevant to older persons, such as the effect on bones and muscles, is less well established. Arterial stiffness, bone demineralization, and muscle loss are all age-related processes with common risk factors, however, whether these are just parallel age-related alterations or whether these processes share common pathways is not yet understood. In this review, we outline previous literature using different assessments of arterial stiffness in various populations across the world to produce a comprehensive overview. Although there are many studies showing an association between arterial stiffness and loss of bone and muscle, the majority are cross-sectional and there is limited longitudinal evidence to justify causal conclusions. We also give an in-depth review of hypotheses and possible mechanisms which may underlie these associations including hormone dysregulation, impaired glucose metabolism, and inflammation. This narrative review highlights the associations between vessels, bones, and muscles with aging, offering insights into possible shared pathways.

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.

Vessel stiffness, calcification and osteoporosis. Common pathogenetic components

Atherosclerosis and osteoporosis until recently were regarded as the diseases of modern society, and their simultaneous development was explained just by the increased chances with longevity. Currently, there are studies showing evidence on these diseases in ancient populations, regardless the age and gender. The diseases found in younger age, with the early Egyptian civilization, witness on the common genetic and behavioral risk factors and pathogenetic components, than simple age-related chance. Scientific publications show more and more data on common properties of these diseases and pathogenetic mechanisms. High risk of premature death from atherosclerosis and osteoporosis complications facilitates the search for individual and general predictors of the disorders with the aim of on-time prevention. Treatment of atherosclerosis and osteoporosis presentation events in one patient demands for a range of medications that leads to polypragmasia. The review is focused on common mechanisms of vascular stiffness development, calcification and bone density decrease. Profound understanding might make it to open novel targets for one drug to both diseases, with decreased rate of complications.

Exposure to tobacco smoke increases bone loss in spontaneously hypertensive rats

PURPOSE

To define if exposure to tobacco smoke (TS) could induce reduction of bone mass and impairment of bone architecture, features observed in osteoporosis in normotensive rats and the influence of TS exposure on the osteoporotic features exhibited in the spontaneously hypertensive (SH) rats.

METHODS

Normotensive Wistar Kyoto (WKY) and SH rats were exposed to filtered air or TS for 8 weeks, then their proximal femurs were extracted for micro-computed tomography (micro-CT) assessment, histological and immune-histological examinations to quantify the adverse influence of TS exposure on the bone mass and density, as well as bone architecture.

RESULTS

We found that TS exposure not only induced significant decreases in bone mineral density (BMD), bone volume (BV), cortical and trabecular thickness (Ct.Th and Tb.Th), trabecular surface area (Tb.Ar), expression of hypoxia-inducible factor-1α (HIF-1α) in the trabecular marrow, delayed ossification of cartilage, as well as statistical increases in trabecular separation (Tb.SP) and the number of trabecular marrow adipocytes in both WKY and SH rats, but also exacerbated multiple features of osteoporosis exhibited in SH rats, including decreased BMD, Ct.Th, Tb.Ar, HIF-1α expression, delayed cartilage ossification, and increased Tb.SP.

CONCLUSIONS

Our results show that TS exposure can reduce bone mass and impair bone architecture and exacerbate multiple features of osteoporosis exhibited in SH rats.