Can antihypertensive medication interfere with the vicious cycle between hypertension and vascular calcification?

Vascular calcification: High incidence sites, distribution, and detection

Vascular calcification is an important pathological change in a variety of disease states such as atherosclerosis (AS), diabetes, chronic kidney disease (CKD), hypertension, and is a strong predictor of cardiovascular events. The distribution and location of calcification in different vessels may have different clinical effects and prognosis. Therefore, the study of high-risk sites of vascular calcification will help us to better understand the prevention, diagnosis, and treatment of related diseases, as well as to evaluate the efficacy and prognosis. So far, although there are some studies on the sites with high incidence of vascular calcification, there is a lack of systematic sorting out the distribution and location of vascular calcification in humans. Based on this, relevant databases were searched, literatures were retrieved, analyzed, and summarized, and the locations of high incidence of vascular calcification and their distribution characteristics, the relationship between high incidence of vascular calcification and hemodynamics, and the common detection methods of high incidence of vascular calcification were systematically described, hoping to provide help for clinical and research.

Antihypertensive treatment with hydrochlorothiazide-hydralazine combination aggravates medial vascular calcification in CKD rats with mineral bone disorder

Background

Arterial stiffness and medial vascular calcification, leading to isolated systolic blood pressure (BP), are major cardiovascular risk factors in patients with chronic kidney disease (CKD) and mineral bone disorders (MBD). The impact of BP on MBD-induced medial vascular calcification in CKD remains uncertain. We investigated whether BP reduction improves arterial stiffness and medial vascular calcification in a rat model of CKD-MBD.

Methods

CKD was induced in Wistar rats by subtotal nephrectomy. Then, MBD was generated by a Ca/P-rich diet with calcitriol supplementation to induce medial vascular calcification. Two antihypertensive treatments were evaluated: (1) the angiotensin AT1 receptor antagonist losartan, and (2) the combination of the thiazide diuretic hydrochlorothiazide and the direct vasodilator hydralazine (HCTZ/HY). After 5 weeks, mean BP (MBP), pulse pressure (PP), and pulse wave velocity (PWV) were determined. Vascular calcification was assessed in the thoracic aorta.

Results

While MBP was similar in CKD-MBD and control CKD rats, PP and PWV were increased in CKD-MBD rats. The heightened arterial stiffness in CKD-MBD rats was associated with diffused medial calcification along the thoracic aorta. Although both losartan and HCTZ/HY reduced MBP in CKD-MBD rats, losartan did not affect PP and PWV nor medial vascular calcification, whereas HCTZ/HY, unexpectedly, further increased arterial stiffness and medial vascular calcification.

Conclusion

In the rat model of CKD-MBD, antihypertensive treatment with losartan did not affect arterial stiffness or medial vascular calcification. However, HCTZ/HY treatment aggravated arterial stiffness and vascular calcification despite a similar reduction of MBP, suggesting a blood pressure-independent mechanism for vascular calcification.

Calcification alters the viscoelastic properties of tendon fascicle bundles depending on matrix content

Tendon fascicle bundles are often used as biological grafts and thus must meet certain quality requirements, such as excluding calcification, which alters the biomechanical properties of soft tissues. In this work, we investigate the influence of early-stage calcification on the mechanical and structural properties of tendon fascicle bundles with varying matrix content. The calcification process was modeled using sample incubation in concentrated simulated body fluid. Mechanical and structural properties were investigated using uniaxial tests with relaxation periods, dynamic mechanical analysis, as well as magnetic resonance imaging and atomic force microscopy. Mechanical tests showed that the initial phase of calcification causes an increase in the elasticity, storage, and loss modulus, as well as a drop in the normalized value of hysteresis. Further calcification of the samples results in decreased modulus of elasticity and a slight increase in the normalized value of hysteresis. Analysis via MRI and scanning electron microscopy showed that incubation alters fibrillar relationships within the tendon structure and the flow of body fluids. In the initial stage of calcification, calcium phosphate crystals are barely visible; however, extending the incubation time for the next 14 days results in the appearance of calcium phosphate crystals within the tendon structure and leads to damage in its structure. Our results show that the calcification process modifies the collagen-matrix relationships and leads to a change in their mechanical properties. These findings will help to understand the pathogenesis of clinical conditions caused by calcification process, leading to the development of effective treatments for these conditions. STATEMENT OF SIGNIFICANCE: This study investigates how calcium mineral deposition in tendons affects their mechanical response and which processes are responsible for this phenomenon. By analyzing the elastic and viscoelastic properties of animal fascicle bundles affected by calcification induced via incubation in concentrated simulated body fluid, the study sheds light on the relationship between structural and biochemical changes in tendons and their altered mechanical response. This understanding is crucial for optimizing tendinopathy treatment and preventing tendon injury. The findings provide insights into the calcification pathway and its resulting changes in the biomechanical behaviors of affected tendons, which have been previously unclear.

Association between pulse pressure and aortic calcification: Findings from the National Health and Nutrition Examination Survey 2013-2014

Dual-energy X-ray absorptiometry (DXA) is a low-cost, minimal radiation technique commonly used to assess bone density and body composition that can also provide a measure of abdominal aortic calcification (AAC). We examined the association between pulse pressure (PP) and DXA-derived AAC in a nationally representative sample of US adults. Analyses were performed in 2,478 adults from the 2013-2014 NHANES cycle. AAC scores were calculated using a validated 24-point scale from thoraco-lumbar spine images (scored 1-6 across four vertebral heights from L1-L4 for both anterior and posterior aortic walls). We examined PP as a predictor of both the presence (dichotomous) and magnitude (continuous) of AAC in age-stratified analyses (<60 years of age and ≥60 years of age) adjusting for traditional cardiovascular disease risk factors, sex, mean arterial pressure and additionally for age and antihypertensive medication. The prevalence of AAC was 25.5%. PP was a predictor of the presence of AAC in fully adjusted models in adults <60 years of age (OR 1.31, P < .05) and ≥60 years of age (OR 1.33, P < .05). PP was also associated with the magnitude of AAC in the overall sample but did not retain significance after separating by age-groups and additionally adjusting for antihypertensive medication. In conclusion, PP is associated with the presence of AAC as measured by DXA in a nationally representative sample of US adults.

Pharmacological and Nutritional Modulation of Vascular Calcification

Vascular calcification is an independent predictor of cardiovascular disease, and therefore, inhibition or regression of this processes is of clinical importance. The standard care regarding prevention and treatment of cardiovascular disease at this moment mainly depends on drug therapy. In animal and preclinical studies, various forms of cardiovascular drug therapy seem to have a positive effect on vascular calcification. In particular, calcium channel blockers and inhibitors of the renin-angiotensin-aldosteron system slowed down arterial calcification in experimental animals. In humans, the results of trials with these drugs are far less pronounced and often contradictory. There is limited evidence that the development of new atherosclerotic lesions may be retarded in patients with coronary artery disease, but existing lesions can hardly be influenced. Although statin therapy has a proven role in the prevention and treatment of cardiovascular morbidity and mortality, it is associated with both regression and acceleration of the vascular calcification process. Recently, nutritional supplements have been recognized as a potential tool to reduce calcification. This is particularly true for vitamin K, which acts as an inhibitor of vascular calcification. In addition to vitamin K, other dietary supplements may also modulate vascular function. In this narrative review, we discuss the current state of knowledge regarding the pharmacological and nutritional possibilities to prevent the development and progression of vascular calcification.

Common Carotid Artery Calcification Impacts on Cognitive Function in Older Patients

INTRODUCTION

Cognitive impairment and dementia represent an emerging health problem. Cardiovascular (CV) risk factors contribute to cognitive impairment.

AIM

To investigate the effect of vascular calcification on cognitive impairment and dementia, independently of plaque and traditional CV risk factors.

METHODS

Four hundred and sixty-nine patients (age of 78.6 ± 6.1 years, 74.4% women) were studied. Traditional CV risk factors levels, cognitive function (MMSE), brain CT scan, and other vascular parameters were measured. Common Carotid Artery (CCA) plaque and calcification were evaluated by ultrasound.

RESULTS

CCA calcification was associated with a lower MMSE score than in subjects with no CCA calcification (23.7 ± 0.3 versus 25.5 ± 0.8; p = 0.015), after controlling for age, sex, education, blood pressure levels, diabetes, creatinine, lipid lowering therapy, neuroimaging alteration, and CCA plaque. Similarly, CCA calcification was associated with higher odds of dementia regardless of the presence of CCA plaque (OR 1.70, 95% CI 1.01-2.94, p < 0.05). This trend was not observed when stratifying patients according to the presence of CCA plaque.

CONCLUSION

CCA calcification is associated with cognitive impairment and dementia, independently of established CV risk factors and CCA plaque. The impact of arterial calcification on cognition seems largely independent of arterial stiffness.